Effects of oxytocin administered in the dry period on subsequent lactation in cows

The need for a dry period in dairy cows has been established for more than a century, but the optimum length of the period and reason for the benefit derived from the pause in lactation has been studied only recently. On the basis of survey studies a dry period of 60-90 days has been shown to result in maximum production. Until a few years ago the stimulus of a dry period to lactation was thought to be due solely to a rebuilding of the nutrient stores in the animal. More recently the involvement of hormonal factors such as an interaction of oxytocin with hormones necessary for maximum lactation has been postulated. Injections of oxytocin during the dry period could simulate the response to milking without evacuation of the gland or loss of nutrients due to lactation. Such treatment would be expected to delay mammary involution and might produce an effect in dry cows similar to those which were not dried off between lactations

A survey of teacher feeling in selected areas concerned with evaluation of teacher service to children

Thesis (Ed.M.)--Boston Universit

Cerebral Single-Photon Emission Computed Tomography Abnormalities in Human Immunodeficiency Virus Type 1-Infected Gay Men without Cognitive Impairment

Objective: To determine whether technetium Tc 99m exametazime single-photon computed emission tomography (SPECT) can distinguish gay human immunodeficiency virus (HIV)—positive subjects, both with and without mild cognitive impairment, from gay HIV-negative control subjects. Design: Twenty HIV-positive subjects (12 without cognitive impairment and eight with mild cognitive impairment) and 10 HIV-negative subjects underwent neurological, neuropsychological, magnetic resonance imaging, and technetium Tc 99m exametazime SPECT examinations. Setting: Subjects were recruited from a natural history study of gay men with HIV infection. Patients: Subjects from the cohort who had previously participated in a magnetic resonance imaging study were selected for the SPECT study. Main Outcome Measures: The SPECT scans were rated as abnormal if focal defects, confirmed by a horizontal profile analysis, were seen. Results: Sixty-seven percent of HIV-positive subjects without cognitive impairment, 88% of HIV-positive subjects with mild cognitive impairment, and 20% of HIV-negative subjects had abnormal SPECT scans (P<.05 for both HIV-positive groups when each group was compared with HIV-negative subjects). Conclusion: Compared with gay HIV-negative control subjects, focal SPECT defects are seen with an increased frequency in HIV-positive gay men without cognitive impairment and in HIV-positive gay men with mild cognitive impairment

Neuropsychological Changes in a Prospectively Followed Cohort of Homosexual and Bisexual Men With and Without HIV Infection

We evaluated neuropsychological test performance of 168 homosexual and bisexual men with and without human immunodeficiency virus (HIV) infection (113 HIV+ subjects and 55 HIV- controls) over 4.5 years of semiannual follow-up. Analyses of the longitudinal data were performed by applying generalized estimating equations (GEEs) to regression analyses with repeated measures. Compared with the HIV- men, the HIV+ subjects performed more poorly on memory testing. Performance on all tests tended to improve over time, but this improvement was attenuated or eliminated in the HIV+ group for tests of language and attention. Within the HIV+ subjects, improvement over time in tests of memory, executive function, language, and attention was attenuated or eliminated in patients with lower CD4 levels; more advanced HIV disease was associated with poorer memory and executive function and with attenuated or reduced learning effects for memory, motor speed, and language tests. Clinically significant neurologic findings were associated with worse memory and orientation and with attenuated or reversed learning effects for memory, language, and attention tests. There were 33 deaths in the HIV+ group. In the men who died, there was more rapid decline in executive, language, and attentional test performance. These observations remained significant after controlling for HIV disease severity. We conclude that HIV infecting the CNS results in progressive cognitive change that is closely associated with neurologic findings. In addition, our findings suggest a relation between more rapid cognitive progression and death

A Prospective Controlled Study of Magnetic Resonance Imaging of the Brain in Gay Men and Parenteral Drug Users with Human Immunodeficiency Virus Infection

To detect the earliest structural changes in the brain in human immunodeficiency virus (HIV) infection, 118 gay men and 115 parenteral drug users enrolled in a study of the natural history of HIV infection underwent magnetic resonance imaging evaluations. Routine T2-weighted and heavily T2-weighted scans for quantification of brain water were obtained, blinded to HIV serostatus. Atrophy and foci of increased signal did not correlate with any medical, immunologic, neurologic, or neuropsychologic parameters in the group as a whole, or in the gay men or parenteral drug user subgroups. Three subjects had progressive multifocal leukoencephalopathy and one had central nervous system lymphoma. In a subgroup in whom intracranial water percent was calculated, correlations were found with CD4 counts and CD4/CD8 ratios. We conclude that standard magnetic resonance imaging of the brain does not differentiate asymptomatic and mildly symptomatic HIV-positive individuals from HIV-negative individuals, regardless of risk group. However, intracranial water percent may distinguish HIV-positive from HIV-negative individuals because it correlates with raw CD4 counts and CD4/CD8 ratios

A Comparison of Cerebral Spect Abnormalities in Hiv-Positive Homosexual Men with and without Cognitive Impairment

Objective: To determine whether technetium Tc 99m exametazime (HMPAO) single-photon emission computed tomography (SPECT) can distinguish between human immunodeficiency virus (HIV)-positive homosexual men with normal neuropsychologic test results and HIV-positive homosexual men with abnormal neuropsychologic test results. Design: Neurologic, neuropsychologic, magnetic resonance imaging, and Tc 99m HMPAO SPECT examinations were performed on 10 HIV-positive homosexual men without cognitive impairment and five HIV-positive homosexual men with cognitive impairment. Patients: Human immunodeficiency virus—positive homosexual men from New York City were recruited for the study. Main Outcome Measures: Findings on SPECT scans were evaluated qualitatively for focal defects, heterogeneity of the cortical margin, white matter hypoperfusion, and decreased global cortical uptake. All SPECT focal defects were coregistered with magnetic resonance images; SPECT heterogeneity and global cortical uptake were also measured quantitatively. Results: Coregistration with magnetic resonance imaging revealed that 63% of the focal SPECT defects corresponded to brain gyri and 37% corresponded to sulci. There was no significant difference in the frequency of qualitative or quantitative SPECT abnormalities between HIV-positive homosexual men with and without cognitive impairment. However, after examining individual neuropsychologic test factors, impaired motor speed performance was associated with decreased quantitative global cerebral uptake. Conclusions: Qualitative SPECT abnormalities are not increased in frequency in HIV-positive homosexual men with global cognitive impairment compared with those in HIV-positive homosexual men without cognitive impairment. Impaired motor speed performance may be associated with decreased quantitative global cerebral uptake

Marine-derived quorum-sensing inhibitory activities enhance the antibacterial efficacy of tobramycin against Pseudomonas aeruginosa.

Bacterial epiphytes isolated from marine eukaryotes were screened for the production of quorum sensing inhibitory compounds (QSIs). Marine isolate KS8, identified as a Pseudoalteromonas sp., was found to display strong quorum sensing inhibitory (QSI) activity against acyl homoserine lactone (AHL)-based reporter strains Chromobacterium violaceum ATCC 12472 and CV026. KS8 supernatant significantly reduced biofilm biomass during biofilm formation (-63%) and in pre-established, mature P. aeruginosa PAO1 biofilms (-33%). KS8 supernatant also caused a 0.97-log reduction (-89%) and a 2-log reduction (-99%) in PAO1 biofilm viable counts in the biofilm formation assay and the biofilm eradication assay respectively. The crude organic extract of KS8 had a minimum inhibitory concentration (MIC) of 2 mg/mL against PAO1 but no minimum bactericidal concentration (MBC) was observed over the concentration range tested (MBC > 16 mg/mL). Sub-MIC concentrations (1 mg/mL) of KS8 crude organic extract significantly reduced the quorum sensing (QS)-dependent production of both pyoverdin and pyocyanin in P. aeruginosa PAO1 without affecting growth. A combinatorial approach using tobramycin and the crude organic extract at 1 mg/mL against planktonic P. aeruginosa PAO1 was found to increase the efficacy of tobramycin ten-fold, decreasing the MIC from 0.75 to 0.075 µg/mL. These data support the validity of approaches combining conventional antibiotic therapy with non-antibiotic compounds to improve the efficacy of current treatments

Risk of Human Immunodeficiency Virus Type 1-Related Neurologic Disease in a Cohort of Intravenous Drug Users

Background: Although the proportion of cases of acquired immunodeficiency syndrome related to intravenous drug use has increased dramatically over the past decade, there has been no longitudinal examination of primary neurologic disease in this group. Objective: To study the development of neurologic disease in human immunodeficiency virus (HIV)—negative and HIV-positive men and women who were intravenous drug users over a 3.5-year period. Design: Prospective observational cohort study. Setting: Subjects were recruited from an infectious disease clinic at a New York City Hospital or from a methadone maintenance program. Participants: Ninety-nine HIV-negative (62 men and 37 women) and 124 HIV-positive (85 men and 39 women) intravenous drug users volunteered. Main Outcome Measure: The development of clinically significant manifestations in six neurologic domains. Results: With multivariate adjustment for current and past substance abuse, age, education, and head injury, we examined the odds of developing HIV-related neurologic disease. Extrapyramidal signs and reduced motor ability became increasingly apparent over time in HIV-infected men as their CD4 cell count declined and as the subjects developed the acquired immunodeficiency syndrome. Fewer neurologic signs were seen in the women. Conclusions: The impact of HIV infection among intravenous drug users parallels that in homosexual men and is independent of alcohol and other drug use

Banner News

https://openspace.dmacc.edu/banner_news/1258/thumbnail.jp