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Biomedical subjects

R L Collins

Publications and source records attributed to R L Collins.

125 records · Page 7Linked to original sources
PubMed1968

Mice unilaterally sensitized for audiogenic seizures.

Strain SJL/J mice exposed to loud bell-ringing (primed) with one ear blocked do not convulse, but are susceptible to audiogenic seizures 48 hours later when stimulated only through the ear open at priming. Mice stimulated through the ear blocked at priming do not convulse, but are convulsible when retested on the opposite ear. The site of sensitization appears to be either in the ear or in those portions of the auditory system receiving input only from one side.

Animals↗
PubMed1968

Audiogenic seizure prone (asp): a gene affecting behavior in linkage group 8 of the mouse.

The incidence of initial audiogenic seizures in mice from crosses between a susceptible and a resistant inbred strain is attributable to the effects of a single pair of alleles. The locus responsible for this behavioral variation is located in Linkage Group VIII of the mouse. Sensitization-dependent convulsions are influenced in whole or in part by alleles at an independent locus.

Alleles↗
PubMedDate not supplied

Obstructive pulmonary disease in rheumatoid arthritis.

Twenty-six of 43 patients (60.5%) with classic rheumatoid arthritis (RA) participating in a controlled, prospective study were found to have maximal midexpiratory flow rates (MMEFs) suggestive of obstructive pulmonary disease. Cigarette smokers with RA had significantly lower MMEFs than either nonsmokers with RA or smokers with degenerative joint disease. There was an increased prevalence of the Pi phenotype MS among the RA patients. Interstitial fibrosis, tobacco smoking, and protease inhibitor deficiencies were all significant factors in producing airway obstruction in patients with RA.

Adult↗
PubMedDate not supplied

Monaural audiogenic seizures: evidence for control by parallel processes.

SJL/J mice were binaurally sensitized and monaurally tested for susceptibility to sound-induced seizure. Most control subjects exhibited the expected biphasic pattern of running. In mice in the experimental groups, the acoustic stimulation was interrupted for less than 20 s at the conclusion of the initial burst of running. During this quiet period, the side of the blocked ear was reversed for some mice. These mice had an independent biphasic seizure when acoustic stimulation was reintroduced, indicating that the biphasic seizure progression characteristic of monaural testing is the result of a lateralized process. We conclude that the locus of this process is probably at the level of the inferior colliculus (IC).

Acoustic Stimulation↗
PubMedDate not supplied

Recovery of susceptibility to audiogenic seizure in mice.

The applicability of the auditory fatigue and anoxia hypotheses for the refractory period observed after sound-induced seizure was examined in SJL/J mice. Duration of auditory stimulation was varied independent of attainment of clonic seizure activity by use of an acoustic interruption technique. Duration of the recovery period affected the pattern of preconvulsive running. Furthermore, the motor asymmetries exhibited during clonus remained consistent across tests. Because duration of acoustic stimulation and attainment of clonus did not affect recovery rate, we conclude that neither the auditory fatigue nor the anoxia hypothesis provides a complete account for the refractory period after audiogenic seizure. We suggest that an inhibitory process, activated before clonus occurs and perhaps linked to depletion of excitatory amino acids in the inferior colliculus, may also be involved.

Acoustic Stimulation↗
PubMedDate not supplied

The effect of patient positioning on mural filling defects during double contrast cystography.

Different radiographic findings may be observed during double contrast cystography due to patient positioning affecting the distribution of positive and negative contrast media. A mass lesion was created in the urinary bladder of a canine cadaver to allow evaluation of the effect of patient positioning on the appearance of a mass during double contrast cystography. The mass appeared as a filling defect only on those views where positive contrast medium surrounded the mass. Otherwise, the mass appeared as a summation. Additionally, a patient is described illustrating the effect of patient positioning on detecting mural filling defects during double contrast cystography.

Animals↗
PubMedDate not supplied

Forgoing life-supporting or death-prolonging therapy: a policy statement.

Avoiding death is not always the preeminent goal of health care, and decisions about the use of life-supporting treatment may either hasten or forestall death. What are the health care professional's responsibilities regarding the use of life-supporting therapy? This report offers general and specific guidelines for termination of life-supporting treatment.

Ethics, Medical↗
PubMedDate not supplied

Fertility desires and intentions of HIV-positive men and women.

CONTEXT: HIV-positive men and women may have fertility desires and may intend to have children. The extent of these desires and intentions and how they may vary by individuals' social and demographic characteristics and health factors is not well understood. METHODS: Interviews were conducted from September through December 1998 with 1,421 HIV-infected adults who were part of the HIV Cost and Services Utilization Study, a nationally representative probability sample of 2,864 HIV-infected adults who were receiving medical care within the contiguous United States in early 1996. RESULTS: Overall, 28-29% of HIV-infected men and women receiving medical care in the United States desire children in the future. Among those desiring children, 69% of women and 59% of men actually expect to have one or more children in the future. The proportion of HIV-infected women desiring a child in the future is somewhat lower than the overall proportion of U.S. women who desire a child. The fertility desires of HIV-infected individuals do not always agree with those of their partners: As many as 20% of HIV-positive men who desire children have a partner who does not Generally, HIV-positive individuals who desire children are younger, have fewer children and report higher ratings of their physical functioning or overall health than their counterparts who do not desire children, yet desire for future childbearing is not related to measures of HIV progression. HIV-positive individuals who expect children are generally younger and less likely to be married than those who do not. Multivariate analyses indicate that black HIlV-positive individuals are more likely to expect children in the future than are others. While HIV-positive women who already have children are significantly less likely than others both to desire and to expect more births, partner's HIV status has mixed effects: Women whose partner's HIVstatus is known are significantly less likely to desire children but are significantly more likely to expect children in the future than are women whose partner's HIV status is unknown. Moreover, personal health status significantly affects women's desire for children in the future but not men's, while health status more strongly influences men's expectations to have children. CONCLUSIONS: The fact that many HIV-infected adults desire and expect to have children has important implications for the prevention of vertical and heterosexual transmission of HIV, the need for counseling to facilitate informed decision-making about childbearing and childrearing, and the future demand for social services for children born to infected parents.

Adult↗
PubMedDate not supplied

Polymorphonuclear leukocyte secretory and metabolic responses to immunoglobulin aggregates.

Biologic activities of soluble immunoglobulin G (IgG) aggregates, insoluble IgG aggregates and precipitates resulting from addition of serum containing rheumatoid factor (RF) to soluble or insoluble IgG aggregates were examined in terms of lysosomal enzyme release and/or stimulation of the hexose monophosphate pathway (HMP) in human polymorphonuclear leukocytes (PMN). Granular enzyme release and HMP stimulation were consistently greater for insoluble aggregates and complexes than for soluble aggregates and controls. One role of IgM rheumatoid factor may be its ability to convert relatively inactive soluble IgG aggregates into insoluble IgG-RF complexes capable of stimulating selective release of PMN lysosomal enzymes.

Glucuronidase↗
PubMedDate not supplied

Ocular pathology, tear production, and tear lysozyme in rheumatoid arthritis.

Ninety-seven rheumatoid arthritis (RA) patients receiving investigational nonsteroidal antiinflammatory drugs were found to have a 31.9% prevalence and 24.5%/year incidence of ocular pathology. None of these ocular lesions were definitely related to their RA or drug therapy. Twenty-one of these patients were studied further for evidence of keratoconjunctivitis sicca. None of these patients had abnormal rose bengal staining, but over half had decreased tear production on both stimulated and unstimulated Schirmer's testing and many patients had high tear lysozyme levels. Increased tear lysozyme levels and decreased Schirmer's tests correlated with a modified rheumatoid activity index.

Adult↗