Showing papers by "University of Tennessee Health Science Center published in 1995"

Efficacy and Safety of Monoclonal Antibody to Human Tumor Necrosis Factor α in Patients With Sepsis Syndrome: A Randomized, Controlled, Double-blind, Multicenter Clinical Trial

Abstract: Objective. —To evaluate the efficacy and safety of anti—tumor necrosis factor α monoclonal antibody (TNF-α MAb) in the treatment of patients with sepsis syndrome. Design. —Randomized, prospective, multicenter, double-blind, placebo-controlled clinical trial. Setting. —A total of 31 hospitals in the United States and Canada. Patients. —There were 994 patients with sepsis syndrome enrolled in this clinical trial, and 971 patients were infused with the study drug. Intervention. —Patients were prospectively stratified into shock or nonshock groups and then randomized to receive a single infusion of 15 mg/kg of TNF-α MAb, 7.5 mg/kg of TNF-α MAb, or placebo. Patients received standard aggressive medical and surgical care during the 28-day postinfusion period. Outcome Measure. —Twenty-eight-day all-cause mortality. Results. —The distribution of variables describing demographics, organ system dysfunction or failure, preinfusion Acute Physiology and Chronic Health Evaluation II score, number of organs failing at baseline, initial sites of infection, infecting microorganisms, antimicrobials used, and initial invasive procedures was similar among patients in the TNF-α MAb and placebo treatment arms. Among all infused patients, there was no difference in all-cause mortality in patients who received placebo as compared with those who received TNF-α MAb. In septic patients with shock (n=478), there was a trend toward a reduction in all-cause mortality, which was most evident 3 days after infusion: 25 of 162 patients treated with 15 mg/kg of TNF-α MAb died, 22 of 156 patients treated with 7.5 mg/kg of TNF-α MAb died, and 44 of 160 patients in the placebo group died (15 mg/kg: 44% reduction vs placebo, P =.01; 7.5 mg/kg: 48.7% reduction vs placebo, P =.004). At day 28, the reduction in mortality for shock patients was not significant for either dose of TNF-α MAb relative to placebo (15 mg/kg, 61 deaths among 162 patients [37.7% mortality]; 7.5 mg/kg, 59 deaths among 156 patients [37.8% mortality]; placebo, 73 deaths among 160 patients [45.6% mortality]; P =.20 for 7.5 mg/kg and P =.15 for 15 mg/kg). Serious adverse events were reported in 4.6% of all infused patients. No immediate hypersensitivity allergic reactions due to TNF-α MAb were reported. Serum sickness—like reactions were seen in 2.5% of patients receiving TNF-α MAb. Conclusions. —There was no decrease in mortality between placebo and TNF-α MAb in all infused patients. In septic shock patients who received TNF-α MAb, a significant reduction in mortality was present 3 days after infusion. Although a trend toward reduced mortality continued at 28 days following treatment with TNF-α MAb, the difference in mortality among shock patients treated with placebo or TNF-α MAb was not significant. ( JAMA . 1995;273:934-941)

Development of the Quality of Life in Epilepsy Inventory

Abstract: We developed an instrument to measure health-related quality of life (HRQOL) in epilepsy. A 99-item inventory was constructed from the RAND 36-Item Health Survey (generic core), with 9 additional generic items, 48 epilepsy-targeted items, and 6 other items concerning attitudes toward epilepsy and self-esteem. We administered the 99-item inventory to 304 adults with epilepsy at 25 epilepsy centers. Patients and patient-designated proxies completed the inventory and were retested 1-91 days later. A multitrait scaling analysis of these data led to retention of 86 items distributed in 17 multiitem scales (Cronbach's alpha ranged from 0.78 to 0.92). Factor analysis of the 17 multiitem scales yielded four underlying dimensions of health: an epilepsy-targeted dimension, a cognitive factor, mental health, and physical health. Construct validity was supported by significant patient-proxy correlations for all scales and correlations between neuropsychologic tests and self-reported emotional and cognitive function (all p values < 0.05). There were significant negative correlations between the four factor scores derived from the HRQOL scales and neurotoxicity, systemic toxicity, and health care utilization (except for the correlation between mental health factor and health care utilization; all p values < 0.05). Patients who were seizure-free in the preceding year reported better HRQOL for the overall score, three of the four factor scores, and 8 of the 17 scale scores than did patients with a high frequency of seizures. Relative validity analysis showed that the epilepsy-targeted factor and three of its four component scales were more sensitive to categorization of patients by severity of seizure frequency and type than scales tapping physical health, mental health, or cognitive function. These cross-sectional data support the reliability and validity of this measure of HRQOL in epilepsy. The addition of an epilepsy-targeted supplement to the generic core improved the sensitivity to severity of epilepsy. The 86 items included in the field testing were supplemented by three additional items to form the Quality of Life in Epilepsy (QOLIE-89) inventory.

TEL/AML1 fusion resulting from a cryptic t(12;21) is the most common genetic lesion in pediatric ALL and defines a subgroup of patients with an excellent prognosis.

Abstract: The t(12;21)(p13;q22) is identified by routine cytogenetics in less than 0.05% of pediatric acute lymphoblastic leukemia (ALL) patients. This translocation encodes a TEL/AML-1 chimeric product comprising the helix-loop-helix domain of TEL, a member of the ETS-like family of transcription factors, fused to AML-1, the DNA-binding subunit of the AML-1/CBF beta transcription factor complex. Both TEL and AML-1 are involved in several myeloid leukemia-associated translocations with AML-1/CBF beta being altered in 20-30% of de novo acute myeloid leukemia (AML) cases. We now demonstrate that a TEL/AML1 chimeric transcript encoded by a cryptic t(12;21) is observed in 22% of pediatric ALL, making it the most common genetic lesion in these patients. Moreover, TEL/AML1 expression defined a distinct subgroup of patients characterized by an age between 1 and 10 years, B lineage immunophenotype, non-hyperdiploid DNA content and an excellent prognosis. These data demonstrate that molecular diagnostic approaches are invaluable in identifying clinically distinct subgroups, and that the AML1/CBF beta transcription complex is the most frequent target of chromosomal rearrangements in human leukemia.

Synthesis of multiple exoproducts in Pseudomonas aeruginosa is under the control of RhlR-RhlI, another set of regulators in strain PAO1 with homology to the autoinducer-responsive LuxR-LuxI family.

Abstract: Mutants of Pseudomonas aeruginosa PAO1 that were deficient in the ability to produce proteases that degrade casein were detected among the survivors of chemical mutagenesis. One such mutant (PDO31) showed reduced production of elastolytic activity, beta-hemolytic activity, and pyocyanin. A 4.3-kb EcoRI fragment from a gene bank of PAO1 that complemented defects in PDO31 was found. Transposon mutagenesis and deletion derivatives of the clone were used in conjunction with complementation tests to determine the physical location of the gene of interest. Nucleotide sequence analysis revealed an open reading frame (rhlR) encoding a putative 27.6-kDa protein (RhlR) with homology to autoinducer-responsive regulators of quorum sensing systems such as LuxR of Vibrio fischeri and LasR of P. aeruginosa. Further sequence analysis downstream of rhlR revealed an independently transcribed gene (rhlI) that encodes a putative 22.2-kDa protein with homology to members of the family of autoinducer synthetases, such as LuxI of V. fischeri and LasI of P. aeruginosa. The rhlRI sequences were also recently reported by others (U.A. Ochsner and J. Reiser, Proc. Natl. Acad. Sci. USA 92: 6424-6428, 1995) as an autoinducer-mediated regulation mechanism for rhamnolipid biosurfactant synthesis in P. aeruginosa PG201. Mutants with defects in rhlR or rhlI were constructed in PAO1 by gene replacement, using clones modified by Tn501 insertion. Compared with the wild type, the rhlR and rhlI mutants both showed defects in the production of elastase, LasA protease, rhamnolipid, and pyocyanin. Transcription from the gene for elastase, as measured with a lasB-cat fusion, demonstrated that production of elastase was subject to cell density-dependent gene activation in PAO1. However, transcription of lasB-cat in the rhlI mutant, which had lost the presumptive autoinducer synthetase (predicted to activate RhlR), showed low basal activity and had lost all cell density-dependent transcription of lasB. Thus, RhlR-RhlI represent the second autoinducer-responsive regulatory mechanism found in P. aeruginosa that controls expression of multiple virulence factor exoproducts, including elastase.

Nonoperative management of blunt hepatic trauma is the treatment of choice for hemodynamically stable patients. Results of a prospective trial.

Abstract: BACKGROUND: A number of retrospective studies recently have been published concerning nonoperative management of minor liver injuries, with cumulative success rates greater than 95%. However, no prospective analysis that involves a large number of higher grade injuries has been reported. The current study was conducted to evaluate the safety of nonoperative management of blunt hepatic trauma in hemodynamically stable patients regardless of injury severity. METHODS: Over a 22-month period, patients with blunt hepatic injury were evaluated prospectively. Unstable patients underwent laparotomies, and stable patients had abdominal computed tomography (CT) scans. Those with nonhepatic operative indications underwent exploration, and the remainder were managed nonoperatively in the trauma intensive care unit. This group was compared with a hemodynamically matched operated cohort of blunt hepatic trauma patients (control subjects) who had been prospectively analyzed. RESULTS: One hundred thirty-six patients had blunt hepatic trauma. Twenty-four (18%) underwent emergent exploration. Of the remaining 112 patients, 12 (11%) failed observation and underwent celiotomy--5 were liver-related failures (5%) and 7 were nonliver related (6%). Liver related failure rates for CT grades I through V were 20%, 3%, 3%, 0%, and 12%, respectively, and rates according to hemoperitoneum were 2% for minimal, 6% for moderate, and 7% for large. The remaining 100 patients were successfully treated without operation--30% had minor injuries (grades I-II) and 70% had major (grades III-V) injuries. There were no differences in admission characteristics between nonoperative success or failures, except admission systolic blood pressure (127 vs. 104; p < 0.04). Comparing the nonoperative group to the control group, there were no differences in admission hemodynamics or hospital length of stay, but nonoperative patients had significantly fewer blood transfusions (1.9 vs. 4.0 units; p < 0.02) and fewer abdominal complications (3% vs. 11%; p < 0.04). CONCLUSIONS: Nonoperative management is safe for hemodynamically stable patients with blunt hepatic injury, regardless of injury severity. There are fewer abdominal complications and less transfusions when compared with a matched cohort of operated patients. Based on admission characteristics or CT scan, it is not possible to predict failures; therefore, intensive care unit monitoring is necessary.

Potassium currents responsible for inward and outward rectification in rat neostriatal spiny projection neurons

Abstract: Many of the nonlinear membrane properties displayed by neostriatal spiny projection neurons are conferred by their voltage-gated potassium (K+) currents, including an inwardly rectifying current (IKir), fast (IAt), and slowly (IAs)-inactivating A-currents, and a slow, noninactivating current. The relative contribution of these K+ currents to the pronounced inward and outward rectification of the current-voltage (I-V) relationship of spiny neurons was investigated in a neostriatal slice preparation. Manipulation of the equilibrium potential for K+ (EK) showed that the voltage dependence of activation of inward rectification was identical to that of IKir. In addition, application of barium (100 microM), which is known to reduce IKir in a time- and voltage-dependent manner, had equivalent effects on inward rectification. Subsequent application of cesium (3 mM) or tetraethylammonium (TEA, 25 mM) blocked inward rectification in a solely voltage-dependent fashion consistent with the action of these blockers on IKir. Administration of 4-aminopyridine (4-AP, 100 microM) at concentrations that selectively depress IAs, reduced outward rectification of spiny neurons at subthreshold membrane potentials. Higher concentrations of 4-AP (2 mM), which block both IAs and IAt, revealed an early transient overshoot in voltage deflections at potentials near spike threshold, but rectification persisted at the end of the responses. The transient overshoot and the residual rectification were eliminated by TEA (25 mM), a blocker of the slow, noninactivating K+ current. Collectively, these results indicate that all three depolarization-activated K+ currents contribute to outward rectification at different times and membrane potentials defined by their voltage dependence of activation and kinetics of inactivation. The spontaneous activity of neostriatal spiny neurons recorded in intact animals is characterized by sustained and limited shifts in membrane potential from relatively hyperpolarized potentials to depolarized potentials near spike threshold. The present data suggest that the hyperpolarized state is determined principally by IKir and the limits on the depolarized state are defined by IAf, IAs, and the noninactivating current. These outward K+ currents also are hypothesized to govern the spike discharge characteristics once the depolarized state has been reached.

Bacterial pyrogenic exotoxins as superantigens.

Abstract: The recent discovery of the mode of interaction between a group of microbial proteins known as superantigens and the immune system has opened a wide area of investigation into the possible role of these molecules in human diseases Superantigens produced by certain viruses and bacteria, including Mycoplasma species, are either secreted or membrane-bound proteins A unique feature of these proteins is that they can interact simultaneously with distinct receptors on different types of cells, resulting in enhanced cell-cell interaction and triggering a series of biochemical reactions that can lead to excessive cell proliferation and the release of inflammatory cytokines However, although superantigens share many features, they can have very different biological effects that are potentiated by host genetic and environmental factors This review focuses on a group of secreted pyrogenic toxins that belong to the superantigen family and highlights some of their structural-functional features and their roles in diseases such as toxic shock and autoimmunity Deciphering the biological activities of the various superantigens and understanding their role in the pathogenesis of microbial infections and their sequelae will enable us to devise means by which we can intervene with their activity and/or manipulate them to our advantage

Effects of parenteral and enteral nutrition on gut-associated lymphoid tissue

Abstract: Changes in mucosal defense have been implicated as important factors affecting infections complications in critically ill patients. To study the effects of nutrient administration on gut-associated lymphatic tissue (GALT), ICR mice were randomized to receive chow plus intravenous saline, intravenous feeding of a total parenteral nutrition (TPN) solution, or enteral feeding of the same TPN solution. In a second series of experiments, a more complex enteral diet (Nutren) was compared with chow feeding and enteral TPN. After 5 days of feeding with experimental diets, lymphocytes were harvested from the mesenteric lymph nodes (MLNs), Peyer's patches (PPs), lamina propria (LP) cells, and intraepithelial (IE) spaces of the small intestine to determine cell yields and phenotypes. Small intestinal washings, gallbladder contents, and sera were collected and analyzed for immunoglobulin A (IgA) levels. In both series of experiments, there were no significant changes within the MLNs. There were significant decreases in total cell yields from the PPs, IE spaces, and LP in animals fed with TPN solution, either enterally or parenterally, as compared with chow-fed mice. Total T cells were decreased in both TPN-fed groups in the PPs and LP, whereas total B cells were decreased in the PP, IE, and LP populations. Total cell numbers remained normal in the Nutrenfed group, except for a decrease in LP T cells. CD4+ LP cells decreased significantly with a reduction in the CD4/CD8 ratio in mice fed TPN solution either intravenously or enterally, whereas IgA recovery from small intestinal washings was significantly decreased in the same groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence for a streptococcal superantigen-driven process in acute guttate psoriasis.

Abstract: Recent studies have suggested that T cells play a critical role in the pathogenesis of psoriasis. Guttate psoriasis is a well-defined form of psoriasis frequently associated with streptococcal throat infection. This study tested the hypothesis that T cells in acute guttate psoriasis skin lesions may be activated by streptococcal superantigens. Peripheral blood as well as lesional and perilesional skin biopsies were analyzed for T cell receptor V beta repertoire using monoclonal antibodies against 10 different V beta families. Skin biopsies from all patients with acute guttate psoriasis, but not skin biopsies from patients with acute atopic dermatitis or inflammatory skin lesions induced in normal subjects with sodium lauryl sulfate, demonstrated selective accumulation of V beta 2+ T cells (P < 0.05). The expansion of V beta 2+ T cells occurred in both the CD4+ and the CD8+ T cell subsets. Sequence analysis of T cell receptor beta chain genes of V beta 2-expressing T cells from skin biopsies of patients with guttate psoriasis showed extensive junctional region diversity that is more compatible with a superantigen rather than a conventional (nominal) antigen-driven T cell response. All streptococcal isolates from patients with guttate psoriasis secreted streptococcal pyrogenic exotoxin C, a superantigen known to stimulate marked V beta 2+ T cell expansion. These data support the concept that acute guttate psoriasis is associated with superantigenic stimulation of T cells triggered by streptococcal superantigen(s).

Differential expression of two basement membrane collagen genes, COL4A6 and COL4A5, demonstrated by immunofluorescence staining using peptide-specific monoclonal antibodies.

Abstract: Genes for the human alpha 5(IV) and alpha 6(IV) collagen chains have a unique arrangement in that they are colocalized on chromosome Xq22 in a head-to-head fashion and appear to share a common bidirectional promoter. In addition we reported a novel observation that the COL4A6 gene is transcribed from two alternative promoters in a tissue-specific manner (Sugimoto, M., T. Oohashi, and Y. Ninomiya. 1994. Proc. Natl. Acad. Sci. USA. 91:11679-11683). To know whether the translation products of both genes are colocalized in various tissues, we raised alpha 5(IV) and alpha 6(IV) chain-specific rat monoclonal antibodies against synthetic peptides reflecting sequences near the carboxy terminus of each noncollagenous (NC)1 domain. By Western blotting alpha 6(IV) chain-specific antibody recognized 27-kD monomers and associated dimers of the human type IV collagen NC1 domain, which is the first demonstration of the presence in tissues of the alpha 6(IV) polypeptide as predicted from its cDNA sequence. Immunofluorescence studies using anti-alpha 6(IV) antibody demonstrated that in human adult kidney the alpha 6(IV) chain was never detected in the glomerular basement membrane, whereas the basement membranes of the Bowman's capsules and distal tubules were positive. The staining pattern of the glomerular basement membrane was quite different from that obtained with the anti-alpha 5(IV) peptide antibody. The alpha 5(IV) and alpha 6(IV) chains were colocalized in the basement membrane in the skin, smooth muscle cells, and adipocytes; however, little if any reaction was seen in basement membranes of cardiac muscles and hepatic sinusoidal endothelial cells. Thus, both genes are expressed in a tissue-specific manner, perhaps due to the unique function of the bidirectional promoter for both genes, which is presumably different from that for COL4A1 and COL4A2.

Cell and molecular analysis of the developing and adult mouse subventricular zone of the cerebral hemispheres

Abstract: The subventricular zone (SVZ) of the lateral ventricle remains mitotically active in the adult mammalian central nervous system (CNS). Recent studies have suggested that this region may contain neuronal precursors (neural stem cells) in adult rodents. A variety of neuronal and glial markers as well as three extracellular matrix (ECM) markers were examined with the hope of understanding factors that may affect the growth and migration of neurons from this region throughout development and in the adult. This study has characterized the subventricular zone of late embryonic, postnatal, and adult mice using several neuronal markers [TuJ1, nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d), neuron- specific enolase (NSE)], glial markers [RC-2, vimentin, glial fibrillary acidic protein (GFAP), galactocerebroside (Gal-C)], ECM markers [tenascin-C (TN-C), chondroitin sulfate, a chondroi tin sulfate proteoglycan termed dermatan sulfate-dependent proteoglycan-1 (DSD-1-PG)], stem-cell marker (nestin), and proliferation-specific marker [bromodeoxyuridine (BrdU)]. TuJ1+ and nestin+ cells (neurons and stem cells, respectively) persist in the region into adulthood, although the numbers of these cells become more sparse as the animal develops, and they appear to be immature compared to the cells in surrounding forebrain structures (e. g., not expressing NSE and having few, if any, processes). Likewise, NADPH-d+ cells are found in and around the SVZ during early postnatal development but become more sparse in the prolifera tive zone through maturity, and, by adulthood, only a few labeled cells can be found at the border between the SVZ and surrounding forebrain structures (e. g., the striatum), and even smaller numbers of positive cells can be found within the adult SVZ proper. BrdU labeling also seems to decrease significantly after the first postnatal week, but it still persists in the SVZ of adult animals. The disappearance of RC-2+ (radial) glia during postnatal development and the persistence of glial-derived ECM molecules such as tenascin and chondroitin sulfate proteoglycans (as well as other “boundary” molecules) in the adult SVZ may be associated with a persistence of immaturity, cell death, and a lack of cell emigration from the SVZ in the adult. © 1995 Wiley-Liss, Inc.

Extent of medial temporal resection on outcome from anterior temporal lobectomy: a randomized prospective study

Abstract: WE REPORT A prospective, randomized, blinded clinical trial comparing seizure and neuropsychological outcomes from anterior temporal lobectomies between two groups of patients. One group (n = 34) underwent hippocampal resection posteriorly to the anterior edge of the cerebral peduncle (partial hippocampectomy). In the other group (n = 36), the hippocampus was removed further to the level of the superior colliculus (total hippocampectomy). The amount of lateral cortical resection was the same between groups. Patients were and neuropsychological morbidity. At 1 year postoperatively, the total hippocampectomy group had a statistically superior seizure outcome compared with the partial hippocampectomy group (69 versus 38% seizure-free), and examination of time to first seizure (survival analysis) revealed significantly superior outcomes associated with total hippocampectomy. There was no increased neuropsychological morbidity associated with the more extensive hippocampal resection.

Effects of nicotine on proliferation and extracellular matrix production of human gingival fibroblasts in vitro

Abstract: Normal function of gingival fibroblasts is essential for maintenance of the gingival extracellular matrix (ECM), but under inflammatory conditions in gingival tissue which may occur with tobacco use, they can also act in its destruction. The purpose of this study was to determine the effects of nicotine, a major component of tobacco, on gingival fibroblast proliferation, the production of fibronectin (FN), and the production and breakdown of type I collagen to elucidate its role in periodontal destruction associated with its use. A human gingival fibroblast strain derived from a healthy individual with non-inflamed gingiva was used in this study. Nicotine at concentrations > 0.075% caused cell death, and at 0.075% and 0.05% it caused transient vacuolization of the fibroblasts. At concentrations of 0.001% to 0.075%, nicotine significantly inhibited proliferation (P or = 0.05% (P or = 0.025% significantly increased collagenase activity (P < or = 0.008), using [3H]-gly and [14C]-pro-labeled type I collagen gels as substrate. The results show that, in vitro, nicotine inhibits the growth of gingival fibroblasts and their production of FN and collagen, while also promoting collagen breakdown. This suggests that nicotine itself may augment the destruction of the gingival ECM occurring during periodontal inflammation associated with smokeless tobacco use.

Management of blunt splenic trauma: computed tomographic contrast blush predicts failure of nonoperative management.

Abstract: Nonoperative management of blunt splenic trauma is widely accepted; however, reported failure rates have ranged as high as 40%. There are few factors available to identify failures reliably. To characterize failures of nonoperative management better, we retrospectively reviewed 309 blunt splenic injuries treated at our level I trauma center over a 5-year period. Eighty-nine patients were initially managed nonoperatively (29%), and 12 patients failed this approach (13%). Upon review of the initial computed tomography scans, a hyperdense collection of contrast media in the splenic parenchyma, or "contrast blush," was noted in 8 of 12 (67%) patients who failed and in 5 of 77 (6%) of those who were successfully managed nonoperatively (p < 0.0001). These data suggest that the presence of a contrast blush is an important consideration when deciding the method for management of the splenic injury. If these results are confirmed in a prospective fashion, the failure rate of nonoperative management of blunt splenic trauma could be reduced by identification of the contrast blush.

Glomerulosclerosis as a determinant of posttransplant function of older donor renal allografts.

Abstract: Transplantation of kidneys from older donors is being advocated to expand the organ donor pool. However, the prevalence of atherosclerosis and age-induced renal structural alterations account for the variable function of allografts procured from these older donors. Pretransplant biopsies are sometimes used to evaluate kidneys from older donors, but to date there are no defined criteria correlating the extent of structural alterations in these kidneys to subsequent function. We investigated the effect of glomerulosclerosis, a marker for nephrosclerosis, on graft outcome. Sixty-five baseline biopsies of kidney allografts were retrospectively analyzed to identify a referent point of glomerulosclerosis that correlated with inferior graft outcome. Age and death from nontraumatic cerebrovascular injuries were the main correlates for donor glomerulosclerosis (P 2.5 mg/dl (n = 13) or nephrectomy (n = 4) had a mean of 20% glomerulosclerosis at the time of implantation compared with only 2% sclerosis in allografts with good function (P 20% sclerosis had an 87% incidence of delayed function (P 20% sclerosis (P 50 yrs) donors and those donors with nontraumatic cerebrovascular accidents, despite seemingly normal preprocurement serum creatinine.

Organization of the avian "corticostriatal" projection system: a retrograde and anterograde pathway tracing study in pigeons.

Abstract: Birds have well-developed basal ganglia within the telencephalon, including a striatum consisting of the medially located lobus parolfactorius (LPO) and the laterally located paleostriatum augmentatum (PA), Relatively little is known, however, about the extent and organization of the telencephalic “cortical” input to the avian basal ganglia (i. e., the avian “corticostriatal” projection system). Using retrograde and anterograde neuroanatomical pathway tracers to address this issue, we found that a large continuous expanse of the outer pallium projects to the striatum of the basal ganglia in pigeons. This expanse includes the Wulst and archistriatum as well as the entire outer rind of the pallium intervening between Wulst and archistriatum, termed by us the pallium externum (PE). In addition, the caudolateral neostriatum (NCL), pyriform cortex, and hippocampal complex also give rise to striatal projections in pigeon. A restricted number of these pallial regions (such as the “limbic” NCL, pyriform cortex, and ventral/caudal parts of the archistriatum) project to such ventral striatal structures as the olfactory tubercle (TO), nucleus accumbens (Ac), and bed nucleus of the stria terminalis (BNST). Such “limbic” pallial areas also project to medialmost LPO and lateralmost PA, while the hyperstriatum accessorium portion of the Wulst, the PE, and the dorsal parts of the archistriatum were found to project primarily to the remainder of LPO (the lateral two-thirds) and PA (the medial four-fifths). The available evidence indicates that the diverse pallial regions projecting to the striatum in birds, as in mammals, are parts of higher order sensory or motor systems. The extensive corticostriatal system in both birds and mammals appears to include two types of pallial neurons: (1) those that project to both striatum and brainstem (i. e., those in the Wulst and the archistriatum) and (2) those that project to striatum but not to brainstem (i. e., those in the PE). The lack of extensive corticostriatal projections from either type of neuron in anamniotes suggests that the anamniote-amniote evolutionary transition was marked by the emergence of the corticostriatal projection system as a prominent source of sensory and motor information for the striatum, possibly facilitating the role of the basal ganglia in movement control. © 1995 Wiley-Liss, Inc.