Showing papers by "University of Alabama at Birmingham published in 1984"

A Meta-Analysis of the Relationships Between Individual Job Satisfaction and Individual Performance

Abstract: The correlational literature concerning the relationships between individual job satisfaction and individual performance was analyzed, using the metaanalysis techniques of Hunter, Schmidt, and Jackson (1982). Higher and more consistent correlations between overall job satisfaction and performance were indicated than those previously reported. Relationships between JDI measures of job satisfaction and performance were not as high or as consistent as those found between overall job satisfaction and performance.

Preferential utilization of the most JH-proximal VH gene segments in pre-B-cell lines.

Abstract: The most JH-proximal VH gene segments are used highly preferentially to form VHDJH rearrangements in pre-B-cell lines. This result demonstrates that the rate at which immunoglobulin VH gene segments recombine is influenced by their chromosomal organization, and that the initial repertoire ofVH genes expressed in pre-B cells is strikingly different from that seen in mature populations.

Spectral sensitivity of a novel photoreceptive system mediating entrainment of mammalian circadian rhythms.

Abstract: Environmental light cycles are the dominant synchronizers of circadian rhythms in the field, and artificial light cycles and pulses are the major tools used in the laboratory to analyse properties of circadian systems1–4. It is therefore surprising that few studies have analysed the physical parameters of light stimuli that affect circadian rhythms. There have previously been no spectral sensitivity measurements for phase shifting the circadian rhythms of mammals and only two preliminary reports on the wavelength dependence of this response exist3,4. Using the magnitude of phase shift caused by a single 15-min pulse of monochromatic light given 6 h after activity onset, we have now characterized the spectral sensitivity of the photoreceptors responsible for phase shifting the locomotor rhythm of the hamster (Mesocricetus auratus). The sensitivity curve for this response has a maximum near 500 nm and is similar to the absorption spectrum for rhodopsin. Although the spectral sensitivity is consistent with a rhodopsin-based photopigment, two features of the photoreceptive system that mediates entrainment are unusual: the threshold of the response is high, especially for a predominantly rod retina like that of the hamster, and the reciprocal relationship between intensity and duration holds for extremely long durations (up to 45 min). These results suggest that the photoreceptive system mediating entrainment is markedly different from that involved in visual image formation.

Mapping by monoclonal antibody detection of glycosaminoglycans in connective tissues

Abstract: Chondroitin sulphate proteoglycans are widespread connective tissue components1–4 and chemical analysis of cartilage and other proteoglycans has demonstrated molecular speciation involving the degree and position of sulphation of the carbohydrate chains5,6. This may, in turn, affect the properties of the glycpsaminoglycan (GAG), particularly with respect to self-association and interactions with other extracellular matrix components6,7. Interactions with specific molecules from different connective tissue types, such as the collagens8,9 and their associated glycoproteins10,11, could be favoured by particular charge organizations on the GAG molecule endowed by the sulphate groups. So far, it has not been possible to identify and map chondroitins of differing sulphation in tissues, but we have now raised three monoclonal antibodies which specifically recognize unsulphated, 4-sulphated and 6-sulphated chondroitin and dermatan sulphate. These provide novel opportunities to study the in vivo distribution of chondroitin sulphate proteoglycans. We demonstrate that chondroitin sulphates exhibit remarkable connective tissue specificity and furthermore provide evidence that some proteoglycans may predominantly carry only one type of chondroitin sulphate chain.

Usable Frequencies in Hyperthermia with Thermal Seeds

Abstract: Temperature distributions are computed for tissue models assumed to be heated by constant power seeds, and from that, the heating power which the implants have to produce to achieve clinically acceptable temperatures in the tumor are obtained. Calculations of the heat produced by thermal seeds exposed to an electromagnetic induction field showed it to be strongly dependent on the permeability of the material, on the field frequency, on the seed diameter, and on the orientation of the implants with respect to the field. It is recommended that, other parameters permitting, the implants be oriented parallel to the induction field and that the field frequency be approximately 200 kHz or lower. Under these conditions, implants with diameters as small as 0.25 mm produce sufflcient heat for any clinical application without undue heating by eddy currents flowing within the patient. The use of frequencies above the recommended range puts certain restrictions on the implant geometry and on the magnetic properties of their material. Needles oriented perpendicular to the field produce enough heat to reach therapeutic temperatures only within a narrow range of parameters.

Auditory receptive fields in primate superior colliculus shift with changes in eye position

Abstract: The process by which sensory signals are transformed into commands for the control of movement is poorly understood. A potential site for such a transformation is the superior colliculus (SC), which receives auditory, visual and somatosensory inputs1–3 and contains neurones that discharge before saccadic eye movements4–6. Along the primary sensory pathways, signals coding the spatial location of auditory, visual and somatosensory targets are based on distinctly different coordinate systems, and it is not known whether each type of sensory input uses a separate motor pathway or if they are converted into a common coordinate system in order to share a single pre-motor circuit. Sensory neurones in the SC have spatially restricted receptive fields (RFs) and are organized into maps across the collicular surface7–9. Acute experiments have shown a rough correspondence between the spatial positions of RFs of neurones encountered along a single dorsal–ventral penetration of the colliculus, regardless of the modality of the effective stimulus10–14, suggesting that auditory, visual and somatosensory maps might be in register. However, in these conditions the head-centred auditory system and the retinotopic visual system are aligned because the eyes are in the primary orbital position15. Moreover, other data have suggested16–18 that the primate SC is organized in motor, not sensory, coordinates, although in the cat, eye position was found to have no effect on auditory receptive fields19. We therefore sought here to determine what happens to the registration of the auditory and visual maps in the alert, behaving animal. Monkeys, with heads fixed, were trained to make delayed saccadic eye movements to auditory or visual targets from one of three initial fixation points while the activity of single neurones was recorded extracellularly. We found that the auditory receptive fields shifted with changes in eye position, allowing the auditory and visual maps to remain in register.

Randomized, Double‐Blind, Placebo Controlled Trial of Low‐Dose Pulse Methotrexate in Psoriatic Arthritis

Abstract: Thirty-seven patients with psoriatic arthritis were entered into a 12-week prospective, controlled, double-blind multicenter trial comparing placebo and oral pulse methotrexate therapy. Methotrexate was given in a dose of 2.5-5.0 mg every 12 hours in 3 consecutive doses per week. A stable background medication program with nonsteroidal antiinflammatory drugs was allowed. Methotrexate was superior to placebo only in physician assessment of arthritis activity and in improvement of the amount of skin surface area with psoriasis. A small but statistically significant rise of serum total bilirubin occurred in the methotrexate-treated patients. No patients were withdrawn from the study for adverse drug effects.

Outcome assessment in clinical trials. Evidence for the sensitivity of a health status measure.

Abstract: Health status measures are conceptually relevant to the assessment of clinical outcome in the rheumatic diseases, but their ability to detect meaningful changes in health has not been clearly demonstrated. This report describes the performance of a self-administered health status questionnaire in a randomized, double-blind, 21-week comparison of placebo, oral gold, and injectable gold in rheumatoid arthritis patients. Outcome was assessed by standard clinical measures, including joint count, grip strength, and laboratory tests, and by the Arthritis Impact Measurement Scales, a reliable and valid health status measure that assesses physical disability, psychological status, and pain. Data from the clinical and health status measures produced highly similar conclusions: injectable and oral gold are more effective than placebo for rheumatoid arthritis, and injections are slightly more effective than oral gold. The health status measure was thus quite sensitive to clinically meaningful drug-induced improvements. These findings provide justification for the further application of health status measures to clinical trials of chronic disease.

Head and neck melanoma in 534 clinical Stage I patients. A prognostic factors analysis and results of surgical treatment.

Abstract: Single and multifactorial analyses were used to evaluate prognosis and results of surgical treatment in 534 clinical Stage I patients with head and neck cutaneous melanoma treated at the University of Alabama in Birmingham (U.S.A.) and the University of Sydney (Australia). This computerized data base was prospectively accumulated in over 90% of cases. Melanomas were about equally distributed between men and women. They were located on the skin of the face in 47%, neck in 27%, scalp in 13%, and the ear in 13% of patients. Both the results of the prognostic factors analyses and the surgical treatment demonstrated that lentigo maligna melanoma (LMM) was distinct from the other two growth patterns, superficial spreading melanoma and nodular melanoma (SSM and NM). In a multifactorial analysis of the 453 patients with SSM and NM, the dominant prognostic variables were tumor thickness (p less than 0.00001), anatomic subsite (p = 0.0213), and ulceration (p = 0.0289). Patients with melanomas on the scalp or neck subsites fared worse than those with tumors located on the face or ear. The results differed for LMM, where thickness was not a significant predictor of survival, and the most dominant prognostic variable was ulceration (p = 0.0042). Local recurrence rates were low, being 2.4% for tumors less than 2.5 mm in thickness, but were 12.3% for tumors greater than or equal to 4.0 mm in thickness. Patients with SSM and NM lesions located on the head and neck had a lower survival rate than those with extremity melanomas in every tumor thickness category, although only those in the 0.76 to 1.49 mm thickness subgroup were significantly different (p = 0.0007). After 5 years of follow-up, patients who underwent an elective lymph node dissection for SSM and NM with a thickness range of 1.5 to 3.99 mm had a better survival (72%) than patients with melanomas of equivalent thickness whose initial treatment was wide excision alone (45%). LMM had a less aggressive biologic behavior compared to SSM or NM and was treated more conservatively. Thus, LMM lesions had an 85% 10-year survival rate with wide excision only, and there was no significant improvement in survival with ELND. Growth patterns, tumor thickness, ulceration, and anatomic subsites should be considered when evaluating risk factors and when making treatment decisions in head and neck melanoma patients.

Loss of pigmentation in Shigella flexneri 2a is correlated with loss of virulence and virulence-associated plasmid.

Abstract: In this study, we examined the relationship between the virulence of Shigella flexneri 2a and the ability of strains of S. flexneri 2a to absorb Congo red. Spontaneous nonpigmented (i.e., unable to bind Congo red [Pcr-]) derivatives of a virulent, pigmented (Pcr+) strain of S. flexneri 2a were isolated and assayed for virulence as determined by their ability to invade epithelial cells. All Pcr- mutants examined lost the ability to invade epithelial cells and were thus avirulent. Agarose gel electrophoresis of plasmid DNA from these avirulent, Pcr- mutants showed that the majority of these strains had lost a plasmid band corresponding to a virulence-associated plasmid, pSf2a140. In many of the mutants, concomitant loss of pigmentation, virulence, and pSf2a140 was accompanied by the appearance of a new plasmid, smaller than pSf2a140. We believe these new plasmids to be deletion derivatives of pSf2a140 and that loss of pigmentation and loss of virulence are associated with deletions in pSf2a140. We transduced Pcr- mutants to Pcr+ and isolated transductants which suppressed the Pcr- phenotype. None of the Pcr+ transductants regained the ability to invade epithelial cells. Several suppressors of the Pcr- phenotype were identified as mutations in cell wall biosynthesis. These results support our belief that although pigmentation is usually associated with virulence, genetic determinants unrelated to virulence can also affect the ability of the cell to bind Congo red. Therefore, the ability of S. flexneri 2a to bind Congo red does not necessarily imply the ability to invade epithelial cells. However, loss of ability to bind Congo red is accompanied by loss of virulence.

Application ofin vivo NMR spectroscopy to cancer

Abstract: A critical review is presented of NMR spectroscopic studies of isolated tumor cells, excised tumors, and in vivo tumors. Although the majority of the studies examined deal with 31P NMR spectroscopy, the potential utility of multinuclear NMR investigations is emphasized. A major theme of this review is the evaluation of the potential applications of in vivo NMR spectroscopy to experimental tumor biology and to the clinical diagnosis and management of cancer. Data are presented demonstrating that this method may prove useful in distinguishing between relatively well vascularized aerobic tumors and poorly vascularized hypoxic tumors. This could provide a basis for identifying tumors responsive to X radiation or hyperthermia. Preliminary experiments point to the possibility that in vivo NMR spectroscopy will be capable of detecting tumor response to chemotherapy, X radiation, and hyperthermia and may also detect drug-induced toxicity to tissues vital to the survival of the host.

The cortical projection of the basolateral amygdaloid nucleus in the rat: a retrograde fluorescent dye study.

Abstract: The fluorescent dye, retrograde labeling technique was used to determine the extent of the projection from the basolateral nucleus of the amygdala to the neocortex in the rat. Each rat received a single cortical injection of fast blue, and in one-half of the animals, a subsequent injection of nuclear yellow was placed in a different cortical region. An analysis of the results demonstrates that the projection to the midline cortex arises in the medial neurons within the caudal two-thirds of the basolateral nucleus. This projection is directed to the anterior cingulate cortex, but not to the posterior cingulate cortex. The primary motor cortex receives a basolateral amygdala projection which originates from neurons in two areas, (1) the medial part of the anterior one-third of the nucleus and (2) the center (in the lateral to medial axis) portion of the posterior two-thirds of the nucleus. The latter neurons are situated lateral to the neurons projecting to the cingulate cortex. Somatosensory cortex injections label many fewer basolateral nucleus neurons than do motor cortex injections, but these neurons are located in a position similar to that of those labeled by motor cortex injections. Finally the gustatory cortex, which lies just dorsal to the rhinal sulcus, receives a basolateral projection from neurons in the lateroventral one-half of the basolateral nucleus. These results demonstrate that the basolateral nucleus gives rise to a rather widespread and topographically organized projection to the anterior half of the neocortex of the rat.

Abnormal central visual pathways in the brain of an albino green monkey (Cercopithecus aethiops)

Abstract: The visual pathways of an albino green monkey have been studied electrophysiologically and by autoradiographic methods. The monkey had a white coat and pink eyes; it had a strabismus and a nystagmus. When comparisons were made with normal macaque and green monkeys, several abnormalities could be defined. In the retina there was no foveal pit. A whole mount preparation showed a central area of high ganglion cell density in which the ganglion cells were significantly larger than the most central ganglion cells of a normal monkey. More peripheral retinal areas showed an apparently normal distribution of ganglion cell sizes and packing densities. Within the optic tract the number of uncrossed retinofugal fibers was less than normal, the part of the tract that represents central vision showing almost no uncrossed component. The uncrossed input to the lateral geniculate nucleus and to the superior colliculus was similarly reduced. Regions normally receiving ipsilateral afferents from the central retina were innervated exclusively by crossed afferents. The pathways to the magnocellular geniculate layers showed a more extensive abnormality than did the pathways to the parvicellular layers. Not only were the afferents to the geniculate layers abnormal, but the laminar pattern in the nucleus was also abnormal. The distinction between magno- and parvicellular layers was less clear than normal in some parts of the nucleus, and there were a number of abnormal laminar fusions. Within the visual cortex it was possible to demonstrate a normal mapping of the contralateral visual field through the contralateral nasal retina and through the peripheral parts of the ipsilateral temporal retina. The central parts of the temporal retina mapped abnormally in the contralateral visual cortex, so that there was a monocular map of the central parts of the visual field forming as a mirror reversal of the normal map. The normal map of the contralateral hemifield formed columns that alternated with the abnormal map of the ipsilateral hemifield. The peripheral parts of the visual field were represented as ocular dominance columns, demonstrable electrophysiologically and also by the transneuronal transport of 3H-proline.

Substrate adhesion of rat hepatocytes: on the mechanism of attachment to fibronectin.

Abstract: We examined the mechanisms of cell attachment to fibronectin-coated substrates. Inhibition of cell attachment was obtained by species-specific antifibronectin antibodies, which presumably recognize a distinct antigenic structure in the protein located at, or in the immediate vicinity of, the cell-binding site. The inhibiting antibodies could be adsorbed on a column of Sepharose substituted with plasma fibronectin. The initial phase of cell attachment was also inhibited by addition of soluble fibronectin to the incubation medium in a reaction that exhibited specificity and concentration dependence. These data suggest that cell-binding sites are available in an active form on the surface of soluble fibronectin. However, the inhibitory effect of fibronectin was greatly enhanced by adding the protein together with heparin, heparan sulfate, collagen, or a fibronectin-binding collagen peptide (CB-7), which is consistent with an "activation" of fibronectin on binding to these matrix components. A similar activation of fibronectin was obtained by cleaving the protein with trypsin. We discuss these findings in relation to conformational rearrangements in the fibronectin molecule. Data is presented supporting a mechanism of cell attachment to fibronectin involving multiple weak interactions between cellular receptors and substrate molecules, although some steps in the attachment process appear to disobey the requirements for such a mechanism.

Psychological aspects of dentofacial esthetics and orthognathic surgery.

Abstract: The literature and the results of the survey clearly confirm that physical attractiveness plays a major role in the social life and interaction among individuals. Cosmetic improvement is a powerful motivating factor leading people to seek treatment. Those who believe that the rewards of facial improvement will enable them to lead more satisfying and comfortable lives should be encouraged to proceed with the treatment. However, it is absolutely essential that those contemplating treatment be counseled before-hand and fully informed on the prognosis, risks and hazards, advantages and disadvantages of such procedures before embarking on treatment.

Malignant small bowel neoplasm of enteric plexus derivation (plexosarcoma). Light and electron microscopic study confirming the origin of the neoplasm.

Abstract: An unusual small intestinal tumor was found in a 61-year-old male who complained of intermittent right lower quadrant burning pain, tenesmus, and bloody diarrhea. On gross examination, the tumor was located intramurally in the distal jejunum with no involvement of the overlying mucosa. Histologic examination revealed two elements: a spindle cell component with characteristics reminiscent of a Schwann cell neoplasm, and nests of larger epithelioid-like cells almost undistinguishable from the Zellballen of nonchromaffin paragangliomas. The neoplasm originated within the intestinal wall without apparent mucosal origin. Ultrastructural studies revealed features recapitulating the normal enteric plexus structure and quite unlike those described in normal or neoplastic smooth muscle, Schwann or paraganglion cells. On this basis, this neoplasm is considered as a malignant enteric plexus tumor or a plexosarcoma.