Single-strand scissions of nuclear yeast DNA occur without meiotic recombination

Summary In meiotic cells of Saccharomyces cerevisiae, reduction in molecular weights of DNA in alkaline sucrose gradients is observed concomittantly with premeiotic DNA replication and with commitment to recombination. Following the completion of the latter processes, higher molecular weights are obtained. These single-stranded breaks are found in both old and newly synthesised strands. Similar scissions in DNA are also found in a temperature-sensitive mutant (cdc40/cdc40), which does not undergo commitment to recombination at the restrictive temperature, and in vegetative wild type cells that were previously exposed to sporulation medium. The suggestion that these scissions are the physical manifestation of commitment to recombination is therefore rejected.     

Selective hippocampal lesion following ω-conotoxin administration in rats

Histopathological evaluation of rat brains 3 days following unilateral i.c.v. injuections of ω-conotoxin GVIA (ω-ctx), 0.032 and 0.1 nmol/kg, was performed. An isolated unilateral lesion confined to the injected hemisphere was found in the hippocampal CA3 neurons. Morphometric analysis of these cells revealed a significant reduction in cell area in both dose groups compared to i.c.v. injected vehicle, and to the contralateral hemisphere. These data indicate a specific degenerative process and suggest that CA3 cells possess ω-ctx-sensitive Ca²⁺ channels which are essential to their viability.     

Comparative performance of the Amplicor HIV-1 Monitor Assay versus NucliSens EasyQ in HIV subtype C-infected patients

In facing global programs for treating HIV-infected patients in the developing countries, there is a real need for viral load assays that are accurate for the local subtypes. The present study was designed to evaluate viral load measurements using the newer version of the NASBA assay in subtype C-infected patients. The performances of this new version, a real-time nucleic acid sequence-based amplification HIV-1 assay (NucliSens EasyQ), were compared to Amplicor HIV-1 Monitor Assay version 1.5 in 79 samples of subtype C-infected patients originating from Ethiopia. Twenty HIV-1 subtype B-infected patients served as a control group. Blood samples from patients in both groups were tested by both assays. The results were compared by a paired, two-tailed Student's t-test. The disparity between the results of the two viral load assays was highly significant in subtype C samples (P = 0.005), such that in the vast majority, higher values of viral load were obtained by the Amplicor assay. However, no differences between the two assays were found in subtype B samples (P = 0.77). CD4 measurements were available for 78 samples of subtype C-infected patients. Of these, a CD4-to-viral load discrepancy (CD4 相似文献   

Breastfeeding may improve nocturnal sleep and reduce infantile colic: Potential role of breast milk melatonin

Melatonin is secreted during the night in adults but not in infants. It has a hypnotic effect as well as a relaxing effect on the smooth muscle of the gastrointestinal tract. It is plausible that breast milk, which consists of melatonin, may have an effect on improving infants' sleep and reducing infantile colic. Our first goal was to assess the differences in the prevalence and severity of infantile colic and nocturnal sleep between breast-fed infants and supplement-fed infants. The second was to characterize the profile of melatonin secretion in human breast milk compared to artificial formulas. Ninety-four mothers of healthy 2 to 4-month-old infants filled a questionnaire regarding irritability/potential infantile colic and sleep characteristics. For the second part, we measured melatonin levels in breast milk of five women every 2 h during 24 h and in three samples of commonly used artificial formulas. Exclusively breast-fed infants had a significantly lower incidence of colic attacks (p = 0.04), lower severity of irritability attacks (p = 0.03), and a trend for longer nocturnal sleep duration (p = 0.06). Melatonin in human milk showed a clear circadian curve and was unmeasurable in all artificial milks. Conclusions. Exclusive breastfeeding is associated with reduced irritability/colic and a tendency toward longer nocturnal sleep. Breast milk (nocturnal) consists of substantial melatonin levels, whereas artificial formulas do not. We speculate that melatonin which is supplied to the infant via breast milk plays a role in improving sleep and reducing colic in breast-fed infants compared to formula-fed ones.     

Continuous control of intraocular pressure in pseudophakic retinal detachment surgery.

We describe a method for continuous control of intraocular pressure in pseudophakic retinal detachment surgery done shortly after extracapsular cataract extraction and posterior chamber intraocular lens implantation. The system consists of a special needle inserted into the anterior chamber through the corneal limbus. The needle is attached by a regular intravenous administration set to an infusion bag. This allows fluids to exit the eye when the eyeball is compressed and to return to the eye when pressure on the eye is released. The presence of an intact posterior capsule and an intraocular lens do not impose a significant barrier to the passage of fluids between the anterior chamber and the vitreous cavity. Using this technique, intraocular pressure can be stabilized throughout the operation. The implementation of this system is demonstrated by a case report.     

Status inconsistency and common mental disorders in the Israel-based world mental health survey

Objective  Research on status inconsistency (SI) and its impact on mental health has been dormant for many years. This study tested the association between SI and emotional distress, anxiety and mood disorders. Methods  Data were gathered from the Israel-based component of the World Mental Health Survey (n = 4,859). SI was defined by the combination of high education (13+ years) with low income (1st decile). Mood and anxiety disorders were diagnosed with the composite international diagnostic instrument (CIDI), and emotional distress was measured with the 12-item general health questionnaire (GHQ-12). Results  Multivariate analysis showed increased risk for mood or anxiety disorders among SI subjects (n = 231), odds ratio (OR) = 1.75, 95% confidence interval (95% CI) 1.13–2.63. The estimate was slightly attenuated when marital status was added to the model (OR = 1.55, 95% CI 1.0–2.39). SI subjects showed higher GHQ-12 scores. Conclusion  SI, which can disrupt an individual’s sense of coherence, is associated, although not causally, with increased 12 month prevalence rates for mood or anxiety disorders and with higher psychological distress.     

Interferon-induced organic mental disorders associated with unsuspected pre-existing neurologic abnormalities

Summary Eleven patients ranging in age from 52 to 80 years, undergoing treatment for cancer with various preparations of interferon received neurobehavioral evaluations after experiencing unexpectedly severe organic mental disorders. The reactions ranged from delirium to extrapyramidal symptoms, mania, and neurasthenia with catatonic episodes. Computed tomographic (CT) scans of the brain disclosed unsuspected pre-existing neurologic abnormalities in all patients, including cerebral atrophy (6/11), brain metastases (4/11), and evidence of head injury incurred 40 years earlier (l/11). These findings suggest that cancer patients with pre-existing neurologic dysfunctions are at increased risk for severe interferon neurotoxicity.     

Hypothalamic sites for cardiovascular and sympathetic modulation by prostaglandin E2

Prostaglandin E₂ (PGE₂, 0.5–5 nmol/kg) injected into the lateral cerebral ventricle of the rat increased the systemic blood pressure and heart rate in a dose dependent manner. These effects were accompanied by increases in plasma norepinephrine and epinephrine concentration. Injection of the low dose of prostaglandin E₂ into discrete hypothalamic nuclei induced a marked increase in heart rate, a moderate increase in the arterial blood pressure and a significant elevation of plasma norepinephrine level. This study suggests a possible central role for PGE₂ in modulation of cardiovascular dynamics and sympathetic nervous activity.     

Some parameters of the use of alcohol by israeli youth and its relationship to their involvement with cannabis and tobacco

This is the third report of an epidemiological study dealing with drugs, cigarettes, and now alcohol, amongst secondary school students in Israel. In the present report we describe general trends of alcohol use, draw socioeconomic profiles of alcohol drinkers, and investigate the relationship with cannabis use and cigarette smoking. Drinking patterns of the research population were studied during the 30 days prior to the administration of a questionnaire in order to devise a scale of their quantity of drinking in relation to a time sequence. Measures were also constructed for the drinking patterns of the family and friends of the research population. One of the overall conclusions is that a higher alcohol consumption is indicated amongst youngsters with a profile of delinquency, involvement with youth activities, personal problems and low parental control.