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Biomedical subjects

S Davis

Publications and source records attributed to S Davis.

At least 361 records · Page 20Linked to original sources

Diabetic amyotrophy: reassessment of the clinical spectrum.

Diabetic amyotrophy is a syndrome whose recognition may be difficult or delayed. We reviewed thirteen patients with this disorder, all of whom had significant proximal lower limb wasting and weakness as the predominant feature and eleven of whom had pain in the affected limbs. Significant weight loss was common. In nine patients the deficits were largely or totally reversible. Important variations from the classical features were observed. Only five patients displayed asymmetric proximal lower limb wasting, weakness and pain, motor deficits in the remainder being either unilateral or bilateral and symmetrical. The shoulder girdle and arms were also involved in two patients. Proximal limb pain was not invariable, a distal sensory peripheral neuropathy was common, and diabetic control at diagnosis was likely to be good. No prognostic factors were identified. Thus, not all patients with diabetic amyotrophy exhibit the classically-described features. Other than careful clinical examination, a thorough bilateral electromyographic and nerve conduction study remains the most helpful diagnostic test. Appreciation of the clinical spectrum and context of diabetic amyotrophy should facilitate its differentiation from other disorders, including other forms of diabetic neuropathy.

Diabetic Neuropathies↗

Spontaneous internal carotid artery dissection presenting as hypoglossal nerve palsy.

A 42-year-old man presented with right temporal headache, dysarthria, and dysphagia. On examination, he had a right hypoglossal nerve palsy. The diagnosis of right internal carotid artery dissection was suggested by magnetic resonance imaging and confirmed by carotid angiography. A dynamic computed tomogram demonstrated enlargement of the carotid artery. In carotid dissection, the hypoglossal nerve may be compromised by local factors as it passes close to the carotid artery in the neck.

Adult↗

The question of autism in an atypical infant.

The evaluation and brief treatment of a less-than-a-year-old girl whose parents were concerned she was autistic is described. We review what is known about the initial symptoms of autism and consider how early it is feasible to make a diagnosis. We outline the domains of cognitive, language, and social development that ought to be monitored given concern about autism and explain how we evaluated these domains in our home-based intervention. Finally, we consider possible explanations for this infant's recovery from a serious early disturbance in social relatedness.

Autistic Disorder↗

Taenia taeniaeformis: cellular reconstruction of athymic mice and role of L3T4+ helper T lymphocytes in the early infection.

The role of T helper lymphocytes (L3T4+) in the early response to Taenia taeniaeformis metacestodes was investigated. Athymic BALB/c-nu/nu mice (susceptible) were inoculated intraperitoneally with the following cell populations from congenic BALB/c-nu+ + mice (resistant): (a) whole spleen single cells, (b) thymus single cell suspensions, or (c) spleen cells pretreated with anti-L3T4 monoclonal antibody before the injection. The mice were given 3 weekly injections of cells and then infected orally with 300 eggs 7 days after the last injection. Cryostat sections of the liver from the infected mice were examined at 6 days postinfection (PI) for parasite viability, the numbers of eosinophils, and L3T4+ T lymphocytes present within 100 micron of the parasite and for the presence of biotin in hepatocytes (involved in biosynthesis of fatty acids) around the parasite. The success of the cellular reconstitution of athymic mice with the lymphoid cells was measured by a T-cell mitogenic assay with concanavalin A (ConA). The cellular reconstitution of athymic mice with a mixture of lymphoid cells from the spleen and thymus of BALB/c-nu/ + mice resulted in both parasite death and eosinophil infiltration. Reconstitution with mature splenic cells alone resulted in a greater parasite killing and eosinophil infiltration as compared to reconstitution with thymic cells. The better reconstitution with splenic cells was reflected in a greater mitogenic response to ConA.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Sacral fractures: an important problem. Retrospective analysis of 236 cases.

Sacral fractures, often undiagnosed and untreated, frequently result in neurologic symptoms and deficits to the lower extremities and urinary, rectal, and sexual dysfunctions. These same neurologic problems often remain the major chronic sequelae after the more obvious pelvic trauma lesion has healed. Specific treatments aimed at neurologic problems are available and may allow the patient functional recovery. This is illustrated by anatomic observations on the sacrum in 39 cadavers showing the relationship among sacral nerve roots within their foramina. These observations were valuable for a retrospective study of 236 consecutive patients with sacral fractures in a series of 776 patients with pelvic injuries. A new classification of sacral fractures evolved from this study and provided a better understanding of the mechanisms responsible for the associated neurologic symptoms. The classification is based on the direction, location, and level of sacral fractures. Three different zones were identified as having characteristic clinical presentations: Zone I, the region of the ala, was occasionally associated with partial damage to the fifth lumbar root. Zone II, the region of the sacral foramina, is frequently associated with sciatica but rarely with bladder dysfunction. Zone III, the region of the central sacral canal, is frequently associated with saddle anesthesia and loss of sphincter function. Routine pelvic roentgenograms were almost useless in identifying the pathologic process in sacral injuries with neurologic symptoms. Ferguson views, tomograms, and particularly computed tomography scans were crucial for understanding these injuries. Cystometrography was most helpful in positively identifying fractures causing neurogenic bladders. Cystometrograms should be ordered routinely in Zone III injuries. Preliminary observations suggest that surgical decompression permitted significantly better neurologic recovery than nonsurgical methods.

Female↗

A comparison of academic performance of female and male optometry students at the University of Missouri-St. Louis.

The number of women entering optometry has risen steadily over the last 2 decades. The present study compares the academic performance of male and female optometry students in the 1984 through 1986 graduating classes at the University of Missouri-St. Louis School of Optometry. The female students had higher grade point averages upon entering optometry school than their male colleagues although they performed less well than the males on the Optometry College Admissions Test (OCAT) examination. An analysis of optometry grade point averages, class rank and honors received at graduation demonstrated that the women performed at least as well academically as their male counterparts.

Educational Status↗

Evaluation of chimpanzee antiserum to human carcinoembryonic antigen.

An adult chimpanzee (Pan troglodyte) with an endogenous circulating carcinoembryonic antigen (CEA) level of 60 ng/ml was immunized s.c. with human CEA. After 1 year of immunizations, the anti-human CEA antibody titer had plateaued. This chimpanzee antiserum demonstrated high avidity specific recognition of human CEA and showed ionic strength effects for CEA recognition similar to those previously described for goat and baboon anti-CEA antisera. Radioimmunoassay of 93 human plasma samples for CEA content using chimpanzee anti-CEA versus Roche goat anti-CEA antisera gave essentially identical results (R = 0.985). Endogenous CEA in chimpanzee blood was very poorly identified by chimpanzee anti-human CEA antisera compared to Roche goat antisera. Column chromatography of human and chimpanzee CEA in the presence of chimpanzee anti-CEA antibody showed only reactivity for the human CEA. In addition, chimpanzee antiserum had only minimal blocking effect on the binding of either goat or baboon antiserum to human CEA. We conclude from these studies that chimpanzee anti-human CEA antiserum recognized a determinant(s) on human CEA which was different from these recognized by goat or baboon antiserum to human CEA and this determinant(s) was poorly represented on chimpanzee CEA. In contrast, the human CEA determinant(s) recognized by baboon and goat anti-CEA antiserums were readily detected on chimpanzee (CEA).

Animals↗

Comparison of multiple anti-CEA immunotoxins active against human adenocarcinoma cells.

Anti-carcinoembryonic antigen (CEA) immunotoxins constructed with multiple anti-CEA antibodies (goat and baboon polyclonal, and three murine monoclonal antibodies) by covalently linking them to the A chain of ricin via a disulfide bond all function as potent and specific toxins for CEA-bearing cells, suggesting that the CEA molecule is capable of directing productive internalization of ricin A chain. The high potency of anti-CEA immunotoxins apparently makes addition of ricin B chain unnecessary for high toxic efficiency, as in some other systems, because presence of the B chain reduces target cell specificity. Several characteristics of the immunotoxins which might account for their cytotoxic potency were studied. Equilibrium association constants of the goat, baboon, and murine monoclonal C-19 antibodies with fluid-phase CEA were determined by using Langmuir plots and were found to be 8.79, 6.61, and 8.13 X 10(9) M-1, respectively, indicating the high and similar affinities of the three antibodies toward CEA. Radioimmunoassay binding studies of the three immunotoxins with 125I-CEA showed that the antibody portions of the molecules retained the ability to form complexes with CEA after conjugation to ricin A chain. The maximum number of anti-CEA antibody molecules bound per cell, as demonstrated by 111In-labeled C-19 binding assays with CEA-bearing cell lines, varied from 2.65 X 10(5) per cell for HT29 to 2.01 X 10(6) for LoVo, with an intermediate value of 1.17 X 10(6) per cell for WiDr. Cytotoxicity of the immunotoxins was assessed by inhibition of protein synthesis and expressed as a median inhibitory dose (ID50). Comparison of the ID50's of each immunotoxin on the three cell lines has shown that the immunotoxin made of the monoclonal C-19 antibody is in general 6 to 7 times more cytotoxic than the goat and baboon antibody immunotoxins. The affinity of CEA-antibody binding is probably an important, but not a sole factor in determining the immunotoxin potency. The fact that the antibodies with very similar affinity toward fluid phase CEA make immunotoxins of different potency might indicate that interactions with membrane-bound CEA are more complex and/or the efficiency of internalization of various immunotoxins is different. An important factor in immunotoxin action appears to be the CEA content in target adenocarcinoma cells.

Adenocarcinoma↗

Breast cancer incidence and month of birth: evidence against an etiologic association.

To investigate the potential relationship between month of birth and breast cancer risk, the authors examined the month of birth of 14,289 women with breast cancer and 38,151 women with cancer of sites other than the breast. All cases were newly diagnosed between 1974 and 1984, and were identified through the Cancer Surveillance System, one of 10 population-based cancer registries comprising the Surveillance, Epidemiology and End Results Program of the National Cancer Institute in the United States. Although breast cancer cases exhibited spring and fall peaks in their month of birth (confirming a previous report), the month of birth of non-breast cancer cases followed a similar distribution. Such patterns have also been reported from populations in other parts of the United States, western Europe, Japan and Australia. These findings suggest that the seasonal variation observed in month of birth of women who develop breast cancer is a reflection of the pattern of births in the underlying population, rather than a new variant in breast cancer epidemiology.

Adult↗

Four conceptualizations of schizophrenia as models for treatment.

As debate continues about the origins and treatment of schizophrenia, the disorder remains a major public health problem both here and abroad. This overview presents four distinct perspectives on schizophrenia, examines the evidence for and against each, and explores implications for treatment. A view of the disorder from a broad perspective is emphasized for effective social work intervention.

Humans↗

The incidence and epidemiologic characteristics of neuroblastoma in the United States.

The incidence of neuroblastoma in the United States is described in relation to age, sex, race, and anatomic site, as well as population-derived indicators of socioeconomic levels, degree of urbanization, and farming activity. Incidence data were obtained for the years 1973-1978 from the Surveillance, Epidemiology and End Results Program of the National Cancer Institute. Based upon 265 cases, the overall incidence of neuroblastoma was 2.26 per million person-years. Approximately 60% of the cases were diagnosed under age two years, 75% under age five years and 84% under age 10 years. The incidence among males was 1.3 times that among females, but the male predominance was observed only among persons diagnosed under age five years. Although no difference in overall incidence was observed by race, the rate among whites was 1.6 times that among blacks and 1.5 times that among other nonwhites under age five years. Approximately 50% of all cases were diagnosed with tumors arising from the adrenals or soft tissues. No clear pattern of area-to-area variation in incidence was identified. Neuroblastoma incidence was inversely related to socioeconomic level as measured by per capita income (p = 0.05), as well as the proportion of county land devoted to farming (p = 0.034). No association was observed in relation to urbanization or population density.

Adolescent↗