Showing papers by "University of Alabama at Birmingham published in 1980"

Epidemiologic studies of Streptococcus pneumoniae in infants: acquisition, carriage, and infection during the first 24 months of life.

Abstract: A natural history study of pneumococcal infection in 82 infants followed from birth is reported. Longitudinal carriage patterns were determined by serial throat and nasopharyngeal cultures. Seventy-nine of 82 infants carried one or more types during the study period. The first type was acquired by a mean age of six months, and the duration of carriage decreased with successive types carried. Acquisition of new types peaked in winter months, but carriage rates fluctuated throughout the year. Thirty-one pneumococcal infections were documented in 24 infants: 28 episodes of otitis media, two of bacteremia, and one of meningitis. Types causing disease were similar to commonly carried types (6, 14, 19 and 23). However, infection usually occurred within one month of acquisition of a new type and was seldom associated with prolonged carriage. In terms of exposure to new strains, 15% (31 of 196) of acquisitions resulted in disease.

Saccades are spatially, not retinocentrically, coded.

Abstract: Most models of the saccadic eye movement system imply that saccades are programmed for a certain distance and direction. Electrical stimulation of the brain was used to move the eyes of monkeys just before saccades to visual targets. Despite the stimulation-induced perturbation, saccades brought gaze to the target locations. This compensation indicates that saccades are coded to direct the eyes to a certain position in the orbit (or in space).

Structure and Metabolism of Connective Tissue Proteoglycans

Abstract: With the possible exception of hyaluronic acid, the connective tissue polysaccharides are all synthesized by their parent cells as components of proteoglycans. In these substances, a number of polysaccharide chains are covalently linked to a protein core; e.g., in the proteoglycan of bovine nasal cartilage, which is the prototype of molecules of this kind, close to 100 chondroitin sulfate chains, with a molecular weight of approximately 20,000, and slightly fewer keratan sulfate chains are linked to a core protein (mol. wt. 200,000) which constitutes 7–8% of the entire molecule. In many respects, the proteoglycans are similar to other protein-bound complex carbohydrates, and the conspicuous polysaccharide component per se does not distinguish the proteoglycans from the class of glycoproteins; e.g., there are members of the glycoprotein class, such as the blood group substances, which have a high relative content of carbohydrate consisting of a substantial number of monosaccharide units. Rather, the segregation of the proteoglycans into a separate category is based on a few specific characteristics: (1) each polysaccharide consists of repeating disaccharide units in which a hexosamine, d-glucosamine, or d-galactosamine is always present; (2) all connective tissue polysaccharides except keratan sulfate contain a uronic acid, either d-glucuronic acid or its 5-epimer, l-iduronic acid, or both; (3) ester sulfate groups are present in all members of the group except in hyaluronic acid; in addition, N-sulfate groups are found in heparin and heparan sulfate. Although certain other bipolymers are known to contain ester sulfate, e.g., some epithelial mucins (Horowitz, 1977), these compounds are clearly distinguishable from the connective tissue polysaccharides by the other criteria indicated above. It may also be mentioned that the d-glucuronic-acid-containing repeating disaccharide of chondroitin, N-acetylchondrosine, has recently been identified as a component of thyroglobulin (Spiro, 1977); however, since the disaccharide is present as a single unit, thyroglobulin may not be considered a proteoglycan.

Outcome of symptomatic congenital cytomegalovirus infection: results of long-term longitudinal follow-up.

Abstract: Thirty-four patients with congenital cytomegalovirus infection who were symptomatic as newborns were followed in a special clinic providing periodic medical and visual examinations as well as psychometric testing and audiometry All patients had symptoms of congenital infection by 2 weeks of age, and 31 of 34 had virus isolated from urine within the first month of life Age at latest follow-up varied from 9 months to 14 years with a mean of about 4 years Ten patients died and 23 surviving patients had adequate follow-up examinations; all but two had evidence of central nervous system or auditory handicaps Microcephaly was present in 16 (70%), mental retardation in 14 (61%), hearing loss in seven (30%), neuromuscular disorders in eight (35%), and chorioretinitis or optic atrophy in five (22%) Children with symptomatic congenital cytomegalovirus infection are at very high risk for handicaps that will significantly impair development

The prognostic significance of ulceration of cutaneous melanoma

Abstract: Ulceration of a cutaneous melanoma on microscopic sections is an adverse prognostic finding. The five-year survival rate is reduced from 80% for non-ulcerated melanomas to 55% in the presence of ulceration for Stage I melanoma patients and from 53 to 12% for Stage II melanoma patients (P less than 0.001). As a group, ulcerated lesions are thicker and more likely to have a nodular growth pattern. However, survival rates were still worse for ulcerated melanomas when matched with nonulcerated lesions for thickness and stage of disease. The width but not the depth of surface ulceration significantly correlated with survival. The median ulcer depth was 0.08 mm (range 0.01-1.2 mm). In those few lesions with ulcer craters more than 0.2 mm in depth, the melanomas were so thick they had the same poor prognosis regardless of whether thickness was measured to the base of the ulcer or to the top of the lesion. The Breslow microstaging method of measuring thickness is therefore a valid prognostic indicator, even for ulcerated lesions. The incidence of ulceration for the entire patient group ranged from 12.5% for melanomas less than 0.76 mm thickness to 72.5% for melanomas greater than 4.0 mm thick (P of correlation = 0.0001); from 12% for Level II invasion to 63% for Level V lesions (P = 0.005); from 23% for superficial spreading growth patterns to 49% for nodular and 74% for polypoid lesions (P = 0.0001); and from 27% for lesions with a heavy lymphocyte infiltration to 60% for minimal or absent host response (P = 0.005). There was no significant correlation with anatomic location, pigmentation of the melanomas, or with the patient's age and sex. Since ulceration appears to have such an important influence on survival rates, this parameter should be considered as a stratification criterion in clinical trials and accounted for when analyzing results of melanoma treatment.

Occupational Disease in Dentistry and Chronic Exposure to Trace Anesthetic Gases

Abstract: Results from a survey of 30,650 dentists and 30,547 chairside assistants suggest that long-term exposure to trace anesthetics in the dental operatory can be associated with increased general health problems and reproductive difficulties. Incidences of spontaneous abortion, congenital abnormalities in offspring, cancer, liver disease, and kidney disease were compared among exposed, nonexposed, and indirectly exposed persons.

Establishment of Mouse Colonic Carcinoma Cell Lines with Different Metastatic Properties

Abstract: Tumorigenic cell lines were established in culture from three transplantable mouse colonic carcinomas designated CT 26, CT36, and CT 51. The cultured lines were characterized for the retention of the biological characteristics of the parental lines. All three cultured lines retained the ability to form tumors in vivo. Serially transplanted parental lines CT 26 and CT 51 grew at a faster rate than did CT 36 and showed a greater propensity for the formation of lung metastases. Similar characteristics were exhibited by the tumors formed from the injection of cultured cells. The cultured cell lines were also evaluated with respect to a number of in vitro markers for cancer. Cultured CT 26 and CT 51 cells formed tumors at lower inocula than did CT 36. CT 26 and CT 51 showed anchorage-independent growth and lack of contact inhibition, while CT 36 grew as a strict monolayer and did not form colonies in 0.27% agarose. CT 26 had the highest saturation density of the cell lines when grown in media supplemented with either 10 or 2.5% fetal bovine serum, while CT 51 had the lowest saturation density under these conditions. The varying degrees of malignancy exhibited by the three cell lines and the overall retention of the biological characteristics of the parental lines by the cultured lines suggest that the cultured cells (without the contaminating stromal elements present in the serially transplanted lines) will provide suitable material for the investigation of the molecular bases of these malignant characteristics.

Long-term evaluation (12 to 22 years) of open heart surgery for tetralogy of Fallot.

Abstract: Four hundred seventy-five patients underwent repair of tetralogy of Fallot from 1955 to 1964; 396 of these were hospital survivors and were followed up for 12 to 22 years. An excellent late clinical result was maintained by 87 percent of the 396 hospital survivors. A less than excellent result in the remaining 13 percent of hospital survivors was caused by late mortality in 7 percent (sudden death in 3 percent, death due to cardiac causes in 2 percent and death due to noncardiac causes in 2 percent), required reoperation in 4 percent (mainly because of residual ventricular septal defect) and development of symptoms in 2 percent. Postoperative cardiomegaly (cardiothoracic ratio greater than 0.55) was observed in 60 (25 percent) of 246 patients who had a follow-up chest roentgenogram, and was more common among those who died late or remained symptomatic. Among the few patients with inadequate surgical relief of right ventricular hypertension who did not have transanular patch repair, the hypertension did not tend to decrease progressively, whereas it did decrease in patients who had patch repair. No late sudden deaths were encountered in 20 patients shown to have postoperative right bundle branch block plus left axis deviation (bifascicular block pattern). Pulmonary valve incompetence appeared to have relatively little harmful influence on the late result, causing cardiac disability in 1 percent of the patients and appeared to be the main contributing factor of postoperative cardiomegaly in 13 (5 percent) of the 246 patients who had a follow-up chest roentgenogram. Most late deaths and complications appeared within 2 years of operation, and accelerating deterioration in late results did not occur as the follow-up extended beyond 2 decades.

Refractive optical systems for irradiance redistribution of collimated radiation: their design and analysis.

Abstract: A set of differential equations is derived which specifies the shape of two aspherical surfaces of a lens system that will convert an incident plane wave with an arbitrary energy profile into collimated radiation with a uniform energy distribution. As an example, a lens system is designed that converts a laser beam with a Gaussian energy profile into an expanded beam with a uniform energy distribution. Off-axis rays are then traced through the lenses in order to analyze the performance of the lens system.

Isolating the effects of symbolic distance, and semantic congruity in comparative judgments: An additive-factors analysis

Abstract: The time needed to compare two symbols increases as the cognitive distance between them on the relevant dimension increases (symbolic distance effect). Furthermore, when subjects are told to choose either the larger or the smaller of two stimuli, the response time is shorter if the instruction is congruent with the overall size of the stimuli (semantic congruity effect). Three experiments were conducted to determine the locus of these effects in terms of a sequence of processing stages. The developmental aspects of these effects were also evaluated, as the subjects were from kindergarten, first grade, third grade, fifth grade, and college. By varying the visual quality of the stimulus in each experiment, it was determined that the distance effect resides in a comparison stage, whereas the congruity effect is an encoding phenomenon. Both distance and congruity effects were present at all grade levels, but they decreased in magnitude as grade increased. The results were interpreted relative to recent models of comparative judgments.

Effect of Corticosteroids on Cataract Formation

Abstract: • While the cataractogenic effects of corticosteroids are beyond dispute, disagreement exists concerning effects of total dose, intensity of dose, and duration of administration on cataract formation. We studied 106 adult male patients matched for age, race, and socioeconomic status. We compared posterior subcapsular (PSC) cataract formation among those with (39) and without (67) a history of systemic corticosteroid therapy. Difference in incidence of PSC opacities among patients with and without a history of corticosteroid therapy was statistically significant. However, no statistically significant correlation was found between PSC opacities and total steroid dose, weekly dose (intensity), duration of dose, or age of patient. Our findings agree with some recent literature that suggests the most important factor in steroid-induced PSC cataract formation may be variability in individual susceptibility to side effects of corticosteroids. We suggest abandoning the concept of a "safe" dose.

Immunoglobulin gene rearrangement in immature B cells.

Abstract: Two types of immature B cells, namely fetal liver hybridomas and the leukemic cell line 70Z/3, both of which have cytoplasmic mu chains but no light chains, were examined for DNA rearrangements of their light chain and heavy chain immunoglobulin genes. In the fetal liver hybridomas, which were constructed from fetal liver cells and a tumor cell, no light chain gene rearrangement was observed, whereas in the 70Z/3 cell line a kappa light chain rearrangement probably occurred. The results suggest that, although the lack of light chain synthesis can be due to a lack of gene rearrangement, there may also be transcriptional regulation, which may also be important for the expression of light chain immunoglobulins in immature B cells.

Psycho-social aspects of chronic pain in spinal cord injury

Abstract: The relationship between persistent pain in spinal cord injury and medical-descriptive, demographic, psychological and familial-social data was studied. Multiple linear regression and discriminant analysis were used to predict (1) presence or absence of pain; (2) severity of pain; (3) time post-injury onset of pain; (4) whether or not pain interfered with activities of daily living. The best combinations of predictor variables accounted for only 15 and 19% of the dependent measures pain vs. no-pain and onset of pain, respectively. The best combinations of predictor variables accounted for 43 and 44%, respectively of the dependent measures severity of pain and whether or not pain interfered with activities of daily living. Higher levels of subjective pain were associated with greater age, higher verbal intelligence, higher levels of anxiety and a more negative psycho-social situation. Persons who reported pain interfering with activities of daily living were more likely to be older, of higher intelligence, more depressed, clinically rated as experiencing greater levels of distress and immersed in a more negative psycho-social environment. The importance of psycho-social variables in the understanding of persistent spinal cord injury pain and the need for prospective studies along these lines are demonstrated.

An assessment of recent advances in external maxillofacial materials

Abstract: A variety of new materials representing several polymer classes and diverse fabrication procedures are now becoming available for use as external maxillofacial prostheses. Because of the availability of these materials, the severely disfigured patient can now be provided an opportunity to elad a near-normal life in today's society. Remarkable advancements have been made in providing the patient with prostheses which feel and look more like skin. Progress has also been made in simplifying fabrication procedures, thus reducing cost. Much remains to be done in materials research. Processing time is still too long for most of the materials. Some of the materials give variable results in the quality and stability of the prostheses because of sensitivity to contaminants and to lab conditions and operator technique. Extrinsic coloration is extremely tedious and diffult with many of the products. The fitting and attachment of the prosthesis to the patient continues to need much improvement. Margins are difficult to mask even with the best materials. Large prostheses of most of the materials are much too heavy and are poorly retained. Staining of the prostheses by foods, cosmetics, and tobacco is a serious problem. The need for an improved material has been recognized by various government agencies and a few of the industrial suppliers of synthetic polymers. Additional advances are sure to result from these efforts.

Computer control of the infusion of vasoactive drugs.

Abstract: In the Cardiac Surgical Intensive Care Unit (CICU) of the University of Alabama Hospital in Birmingham, Alabama, the mean arterial pressure (MAP) is regulated by computer (H-P 21 MX) controlled infusion of vasodilating agents and has been performed in 1100 hypertensive patients following open heart surgery.

Neural effects on sinus rate and atrioventricular conduction produced by electrical stimulation from a transvenous electrode catheter in the canine right pulmonary artery.

Abstract: We studied the effects on sinus rate and atrioventricular (AV) conduction of electrical stimulation from a 12-polar electrode catheter advanced into the right pulmonary artery of 21 anesthetized dogs. In each experiment, the distal tip of the electrode catheter was positioned at a standard fluoroscopic site, and a sequence of bipolar electrograms was recorded during sinus rhythm from the 11 adjacent catheter electrode pairs using a standardized technique. Within each sequence of electrograms, a characteristic change in the polarity of the atrial complexes was identified at a site in the proximal right pulmonary artery. This recording site was labeled the site of initial polarity transition. Stimulus-strength response testing was performed from each catheter electrode pair during spontaneous sinus rhythm and during atrial fibrillation sustained by rapid atrial pacing. The least stimulus strengths required to slow sinus rate or to depress AV conduction were obtained using an electrode pair at a proximal right pulmonary artery site identified as the optimal stimulation site. This stimulation site was at, or immediately proximal to, the recording site of initial polarity transition. Stimulation distal to the site of initial polarity transition precipitated atrial fibrillation using stimulus strengths which were very low compared to stimulus strengths required to precipitate atrial fibrillation at more proximal sites. Negative chronotropic and negative dromotropic effects persisted throughout 5-minute periods of stimulation from the optimal stimulation site and could be modulated by varying stimulus parameters. Using neurophysiological and neuropharmacological techniques, we demonstrated that these effects were produced by stimulation of preganglionic parasympathetic efferent nerve fibers. Circ Res 46: 48-57, 1980

Retinal ganglion cells projecting to the rabbit accessory optic system.

Abstract: Recent evidence from extracellular recording studies indicates that the medial terminal nucleus (MTN) of the rabbit accessory optic system receives inputs from a particular functional class of retinal ganglion cells--specifically, the on-type direction-selective cells. These ganglion cells have been selectively labeled by the retrograde transport of horseradish peroxidase (HRP) injected into the MTN. The number of labeled cells, their distribution over the retina, and their soma areas were determined. In one animal in which the HRP injection completely filled the nucleus, two thousand ganglion cells were labeled. This number agrees with previous estimates of the number of retinal axons terminating in the MTN. Unlike results in avians, none of the ganglion cells was displaced--i.e., they were not Dogiel cells. The density of labeled cells was highest in the visual streak and, overall, the distribution of labeled cells corresponded to the physiologically determined distribution of on-type direction-selective cells. Cells labeled by the HRP injection were among the 20% largest cells in the retina. This result, in conjunction with conclusions from other studies, leads to the prediction that on-type direction-selective cells can be characterized morphologically as cells with large cell bodies and a very extensive dendritic spread in which the dendrites ramify in the vitreal sublamina of the inner plexiform layer.

Surgical management of regional lymph nodes in cutaneous melanoma

Abstract: The initial evaluation of melanoma patients should include an assessment of the regional lymph nodes for metastatic disease. Clinical palpation of the nodes is an important but relatively crude index of metastatic melanoma. In clinically normal nodes, the risk of microscopic metastatic melanoma can be predicted by such prognostic factors as thickness, ulceration, and anatomic location of the melanoma. Other prognostic factors, including the level of invasion and growth pattern (nodular and superficial spreading) provided no additional predictive information after these dominant factors were accounted for. Stage I patients with intermediate thickness melanoma (0.76–4.00 mm) have an improved survival rate with elective Iymphadenectomy, while those with thin (

Replacement of the Ascending Aorta and Aortic Valve with a Composite Graft: Results in 86 Patients

Abstract: We reviewed our entire experience with composite graft replacement of the ascending aorta and aortic valve during a 63 month interval ending in December, 1979. Anuloaortic ectasia was the most common indication for operation, followed by aortic dissection (acute and chronic). Hospital mortality was 5% and was related to the preoperative functional status and the duration of intraoperative myocardial ischemia. Reoperation on the ascending aorta for reasons other than postoperative hemorrhage was required in five of the 82 hospital survivors (6%). By actuarial analysis, 90% of hospital survivors were free of any reoperation on the ascending aorta or aortic valve three years postoperatively, and 93% were free of reoperation related specifically to the composite graft. Pseudoaneurysms at the coronary ostia or distal aortic anastomosis were observed in five of 16 patients having postoperative angiography. One of the five patients has required reoperation. Follow-up has averaged 23.5 months (range: 0.2-60 months). Three year actuarial survival for the 86 patients was 81%, for 44 patients with anuloaortic ectasia was 88%, and for 31 patients with aortic dissection was 83%. Composite graft replacement of the ascending aorta and aortic valve is a satisfactory alternative to supracoronary graft replacement and aortic valve replacement. It offers the advantage of excluding all aneurysmal tissue from the aortic anulus to the innominate artery, thereby eliminating the potential for later development of aneurysms of the sinuses of Valsalva, a known complication of the supracoronary technique. It is the method of choice for patients with anuloaortic ectasia and cephalad displacement of the coronary ostia. It is suitable for many patients with acute or chronic dissection and for patients with sinuses of Valsalva aneurysms following previous operations on the ascending aorta or aortic valve.

Effects of Anti‐Ig Antibodies on the Development and Differentiation of B Cells

Abstract: It is now well known that B cells characteristically express immunoglobulin receptors on their surface. On average, each B lymphocyte bears approximately 10̂ immunoglobulin molecules on its outer cell membrane. A relatively small portion of the carboxy terminal end of the immunoglobulin molecule is embedded in the fluid membrane, and the rest of the surface antibody receptor is exposed. Since these receptors for antigen are intimately involved both in antigen triggering of the immune response and in the induction of specific immune tolerance, it is perhaps not surprising that cross-linkage of surface immunoglobulins with divalent ;mti-Ig antibodies may have either positive or negative effects. Our studies of the effects of anti-Ig antibodies have been concerned chiefly with their inhibitory effects on B cells. We have used antibodies specific for immunoglobulin isotype and allotypic determinants to examine different stages in the life history of B cells. These studies, conducted in chickens, mice, rabbits and humans, led directly to demonstration of the existence of an immature IgM* B lymphocyte whose development is easily blocked by cross-linkage of surface IgM molecules and which has the capacity to give rise to B cells which produce other immunoglobulin isotypes. Indirectly these studies led to the identification of a very immature cell type of B lineage in mammals, the so-called pre-B cell, which has the unusual feature of expressing;/ chains only in the cytoplasm, i.e., surface immunogiobulin receptors are lacking. It is during this stage in differentiation that allelic exclusion is expressed and the process of clonal diversity is initiated.