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Biomedical subjects

C E Barr

Publications and source records attributed to C E Barr.

At least 19 recordsLinked to original sources
PubMed1992

Oral diseases in HIV-1 infection.

HIV-associated oral lesions have been reported since the beginning of the AIDS epidemic, be they fungal, viral, bacterial, neoplastic, or non-specific in origin. The most common lesions are oral candidiasis (OC; noted in several forms) and oral hairy leukoplakia (OHL). OC appears to be directly related to levels of immunosuppression while OHL, a newly described lesion, is associated with the Epstein-Barr virus. Although prevalence data for all types of oral lesions are scarce, this review identifies and describes those reported most often. Lesions associated with HIV may appear on most oral mucosal surfaces and may differ from those seen on other body areas. The role of saliva in reducing the potential for transmission of the HIV virus appears to be significant. Physicians and dentists should cooperate in the management of the HIV patient who has oral disease.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Oral manifestations of HIV infection. Definitions, diagnostic criteria, and principles of therapy. The U.S.A. Oral AIDS Collaborative Group.

A set of definitions and diagnostic criteria for the more common oral features of human immunodeficiency virus infection were prepared as the result of a consensus reached by a group of dental and medical clinicians, epidemiologists, and other experts. These are intended for use in epidemiologic surveys, where the presumptive diagnoses are recommended, and in clinical care, pathogenesis and therapy studies, where the definitive diagnoses are appropriate.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Longitudinal study of parotid saliva in HIV-1 infection.

Parotid flow rate and chemistry of 78 HIV + gay/bisexual men and 27 HIV-gay/bisexual controls were compared on a longitudinal basis at 4-month intervals over a 1 yr period for changes indicative of inflammatory or autoimmune diseases of the salivary glands, or reduced protective capacity toward oral opportunistic infection. Parotid saliva was examined for concentrations of sodium, chloride, phosphate, total protein, lysozyme, lactoferrin, secretory IgA, salivary peroxidase, histatin and albumin. Chloride, lysozyme and peroxidase were significantly higher in HIV + at all 3 examinations and increased in concentration over time. Although mean values for stimulated flow rate were not significantly different in the two groups over the year, there was a significant increase in the number of HIV + with reduced flow over time. In 6% of HIV + there was a marked reduction in flow rate and Sjögren's syndrome-like elevations in parotid chemistry but no enlargement. At all examinations low flow rate was significantly related to oral candidiasis; T4 levels were inversely related to oral candidiasis, but not to concentration of salivary components or flow rate; nor was AZT use. As a group the HIV + patients maintained normal flow rate and secreted normal or elevated concentrations of protective proteins. A subgroup, however, exhibited diminished flow over time and an increasing tendency to oral candidiasis and a diminution in output of histatins.

Adult↗
PubMed1992

HIV-associated oral lesions; immunologic, virologic and salivary parameters.

There are numerous reports of oral lesions in HIV-infected individuals. However, few correlate the oral lesions with laboratory parameters. This study examined oral candidiasis and hairy leukoplakia, the two most common HIV-associated oral lesions, in relation to T-cell counts, p24 core antigen levels and salivary flow rates. Oral mucosal examinations, immunologic and virologic studies and stimulated whole and parotid saliva flow rates were conducted on 135 (HIV+ = 102, HIV- = 33) homosexual or bisexual men. Results indicate that, among HIV-infected subjects, the odds of having oral candidiasis is 6 times (95% CI = 0.6-56.6) greater for subjects with T4 counts between 200-399 per mm3, and 23 times (95% CI = 2.8-193.0) greater for subjects with T4 counts less than 200/mm3 compared to subjects with T4 counts of 400/mm3 or greater. Subjects had an equal likelihood of having hairy leukoplakia at different levels of immunocompetence. The prevalence of oral candidiasis and hairy leukoplakia was higher among subjects with infectious virus in their serum, but was only statistically significant for hairy leukoplakia (p = 0.01).

Adult↗
PubMed1992

Recovery of infectious HIV-1 from whole saliva.

Whole saliva and serum samples were collected from 75 HIV-infected homosexual or bisexual men. Thirty-eight percent of cultured sera were positive for cell-free, infectious virus while only 1 percent of the 218 cultured whole salivas contained cell-free, infectious virus. These data support previous studies suggesting unlikely potential transmissibility of HIV infection by saliva.

Adult↗
PubMed1990

Exposure to influenza epidemics during gestation and adult schizophrenia. A 40-year study.

We attempted to replicate earlier findings of an association between exposure to influenza in the second trimester of gestation and adult schizophrenia. The number of live births, of births of future schizophrenics, and of cases of influenza reported to the Ministry of Health in Denmark was ascertained by month from 1911 to 1950. The relationship between fetal exposure to influenza and adult schizophrenia was examined. It is possible that unknown factors produce excesses of both influenza and schizophrenia in the winter, creating an artifactual association. To control for this coincidence, the effects of season were removed from the monthly influenza and schizophrenic birth-rates by several methods. Using the residual scores, it was found that influenza rates higher than seasonally expected, occurring in the sixth month of gestation, were associated with rates of births of schizophrenics greater than seasonally expected. This association was not attributable to some winter-related, third factor or to climatic variables.

Adult↗
PubMed1989

Fetal neural development and schizophrenia.

The conference on Fetal Neural Development and Schizophrenia which was held in Washington, DC, May 31-June 1, 1988, focused on factors of possible etiological significance in fetal development. Schizophrenia researchers joined experts in brain imaging, neuropathological, and neurochemical changes in brain development and investigators of potential genetic and neurobehavioral causes of psychosis. The combined evidence suggested dysfunction in frontal and parieto-occipital neocortex, basal ganglia, hippocampus, and amygdala. Dopamine transmission was implicated both in basal ganglia deficits and in widespread neocortical disturbances. Viral infection, or excessive stress, during the second trimester of pregnancy, as well as obstetrical complications, minor physical anomalies, and brain defects, correlated positively with incidence of adult schizophrenia. Autonomic nonresponding, birth complications, and ventricular enlargement were found to be closely related to negative symptom schizophrenia in high-risk populations. A dual factor model of schizophrenia was suggested, where genetic and environmental influences combine to produce psychosis.

Brain↗
PubMed1986

The electroencephalographic pattern during electroconvulsive therapy. III. Analysis of frontotemporal and nasopharyngeal spectral energy.

This study analyzes the frontotemporal and nasopharyngeal spectral energy of an ECT-induced seizure, in order to investigate the origin of the final Phase III activity, which contains most of the seizure's energy. Data supports these findings: energy in the delta frequency band is responsible for the generation, propagation, and maintenance of Phase III of the ECT-induced seizure; the synchronous "delta-firing" depolarizations of Phase III are recurrently initiated by an ECT-induced "generator" process; higher magnitudes of energy are generated centrally than are generated laterally during Phase III; and the lessened memory impairment associated with nondominant unilateral ECT is attributable to the markedly lower peak and total energies observed in the unstimulated temporal lobe.

Brain↗
PubMed1985

Cytomegalovirus presence and salivary composition in acquired immunodeficiency syndrome.

Parotid and whole saliva was collected from nine patients with acquired immunodeficiency syndrome (AIDS) and nine controls. Cytomegalovirus (CMV) was cultured from both salivary samples in six of the AIDS patients but was not present in any of the controls. In the AIDS samples parotid sodium (p less than 0.05), IgG (p less than 0.01), and albumin (p less than 0.05) were higher than in control samples. Parotid potassium (p less than 0.05) and total protein (p less than 0.05) were lower than control values, whereas flow rate, lactoferrin, lysozyme, IgA, and IgM levels were similar in both sets of samples. AIDS does not appear to affect secretory IgA levels. Sodium (p less than 0.01) and IgA (p less than 0.05) were higher in the whole saliva of AIDS patients. Serum IgG, IgM (p less than 0.01), and IgA (p less than 0.05) were also elevated when compared with the controls. The prevalence of CMV in parotid and whole saliva of AIDS patients is consistent with the known susceptibility of this group to adventitious infection and the predilection of this virus for the salivary glands. The changes in salivary composition suggest a low level of inflammation, which occurs independently of the virus.

Acquired Immunodeficiency Syndrome↗
PubMed1979

A simplified method for intracavitary radiation for recurrent nasopharyngeal carcinoma.

A simplified method for constructing a custom-made mold to hold radium for intracavitary radiation therapy of recurrent nasopharyngeal carcinoma was developed. The technique for fabrication and insertion of the mold in a single operative procedure is described. Computer dose distributions were obtained and the applications were well tolerated by the patients.

Acrylic Resins↗
PubMed1978

Potassium transference in Nitella.

Transmembrane movements of K+ and Cl- were studied under a variety of experimental conditions. Potassium was found to carry more than 50% of an externally applied inward positive current. The increase in K+ influx was much greater than that predicted by the purely passive model. The increase in Cl- efflux accounted for less than 10% of the applied current, in agreement with the value predicted for passive movement. 2,4-Dinitrophenol (DNP) caused an 80% reduction in K+ transference and a corresponding increase in the measured electrical resistance of the membrane. DNP also reduced the isotopically measured resting K+ influx and caused a substantial increase in both Cl- influx and efflux. Lowering of the pH from 5.7 to 4.7 also reduced the net K+ influx but without drastically altering the membrane resistance. It appears the major portion of an externally applied current does not travel through passive channels, but rather is shunted through a different membrane component. In conjunction with evidence previously establishing the H+ pump as the primary ion pump in Nitella, the data presented here are consistent with a K+/H+ exchange mechanism which can account for the observed net K+ accumulation and maintenance of the membrane potential above the electrochemical equilibrium potential of the major ions. This mechanism appears to be a likely candidate for the current shunt.

Biological Transport, Active↗