Widespread Integration and Survival of Adult-Derived Neural Progenitor Cells in the Developing Optic Retina

Adult rat hippocampus-derived neural progenitor cells (AHPC) show considerable adaptability following grafting to several brain regions. To evaluate the plasticity of AHPCs within the optic retina, retrovirally engineered AHPCs were grafted into the vitreous cavity of the adult and newborn rat eye. Within the adult eye, AHPCs formed a uniform nondisruptive lamina in intimate contact with the inner limiting membrane. Within 4 weeks of grafting to the developing eye, the AHPCs were well integrated into the retina and adopted the morphologies and positions of Müller, amacrine, bipolar, horizontal, photoreceptor, and astroglial cells. Although the cells expressed neuronal or glial markers, none acquired end-stage markers unique to retinal neurons. This suggests that the adult-derived stem cells can adapt to a wide variety of heterologous environments and express some but not all features of retinal cells when exposed to the cues present late in retinal development.     

Prolongation of inhibitory postsynaptic currents by pentobarbitone, halothane and ketamine in CA1 pyramidal cells in rat hippocampus.

Spontaneous inhibitory postsynaptic currents (i.p.s.cs) were recorded in voltage-clamped CA1 neurones in rat hippocampal slices. The exponential decay of i.p.s.cs was prolonged by concentrations of sodium pentobarbitone as low as 50 microM. With concentrations up to 100 microM, there was no change in the amplitude or rise time of the currents but current amplitude was depressed at 200 microM. The prolongation of currents increased with drug concentration within the range tested (50 to 200 microM). Halothane, at concentrations from 1 to 5%, also increased the time constant of decay of i.p.s.cs. The effect increased with concentration and was fully reversible. Ketamine, at a concentration of 0.5 mM, increased the time constant of decay of i.p.s.cs by 50 to 80% and the effect was reversible. Ethanol (10-200 mM), nitrous oxide (75-80%), and caffeine (10 microM-5 mM) had no detectable effect on the i.p.s.cs. It is suggested that pentobarbitone, halothane and ketamine increase the time constant of decay of the i.p.s.cs by stabilizing the open state of channels activated by gamma-aminobutyric acid.     

Supraacetabular insufficiency fractures

Insufficiency fractures in the supraacetabular region were identified in five women, aged 55-83 years. Factors contributing to the diminished resistance of their bones included postmenopausal osteoporosis, steroid therapy, radiation therapy, and rheumatoid arthritis. The supraacetabular fractures were seen on routine radiographs as hazy bands of sclerosis located immediately above and parallel to the acetabular roof. All five patients had additional fractures in the spine or pelvis. Supraacetabular insufficiency fractures may be an unsuspected cause of hip pain, especially in older women.     

Collagenase from corneal cell cultures and its modulation by phagocytosis.

The uptake of latex by fibroblasts in confluent primary culture results in the secretion of collagenase at a linear rate for a prolonged period. Phagocytosis might therefore constitute an important level of collagenase regulation in corneal ulceration. The collagenase in cell cultures is present in a latent form (40,000 MW) like that obtained from organ cultures of ulcerating corneas and can be activated proteolytically. Production of the latent collagenase in cell culture depends upon the presence of serum and diminishes greatly when serum is removed from the medium. Collagenase activity can be demonstrated after the latent collagenase has been separated from serum antiproteases in the media. Alternatively, careful titration of the crude media with trypsin to saturate serum antiproteases, to release collagenase from the complex with alpha 2-macroglobulin, and to activate latent collagenase also results in measurable collagenase activity. The collagenase that is secreted cleaves fibrillar type I collagen and cleaves soluble type I collagen into the typical 3/4 and 1/4 length fragments, as demonstrated by SDS-gel electrophoresis and electron microscopy.     

Cryosurgery of major and minor salivary gland: a light microscopic evaluation in the Rhesus monkey.

The minor salivary glands in the hard palate and the submandibular gland of the Rhesus monkey were subjected to a liquid nitrogen, direct-spray, one-cycle freeze. A 4-min freeze in the temperature range of -40 degrees C to -60 degrees C was used. The extent of tissue destruction was determined at intervals up to 1 year. Clinically relevant findings resulted and form the basis for subsequent studies by this group of investigators.     

Mechanisms for the biodegradation of organic mercury compounds: the action of ascorbate and of soluble proteins.

Organic mercury compounds are to varying extents degraded by ascorbate and by soluble proteins. Phenyl-, methyl-, and methoxyethyl mercury are attacked by ascorbate, provided that the solution has been exposed to air in the presence of Cu²⁺, although the reaction can subsequently proceed in the absence of air. Mercury vapour (Hg⁰) and inorganic mercury (Hg²⁺) are released, and the $\text{Hg}{}^0\text{Hg}{}^{\mathrm{2+}}$ ratio varies with the three compounds, being high with methoxyethyl-mercury and very low with methylmercury. The $\text{Hg}{}^0\text{Hg}{}^{\mathrm{2+}}$ ratio is much reduced in the presence of cysteine. It is suggested that the ascorbate free radical is responsible for the reaction. γ-Globulin can degrade phenyl-mercury, but not methyl- and methoxyethylmercury, to yield Hg²⁺. The action is much stimulated by glutathione and dithiothreitol, and the evidence suggests that these act by reducing protein disulphide groups, and that the Hg²⁺ released remains attached to reactive protein thiol groups. Serum albumin appears to have a similar action. Most of the activity of the soluble fraction of a rat liver homogenate can be accounted for by the presence of thiol-activated proteins.     

Women's experience of intimate partner violence in Haiti

This study examined individual, partner, and community characteristics associated with the occurrence of intimate partner violence among ever-married women of reproductive age, using data from the 2000 Haiti Demographic and Health Survey. Separate logistic regressions were analyzed to assess women's risks of experiencing emotional, physical and sexual violence and multiple forms of intimate partner violence in the past 12 months. Twenty-nine percent of women in the sample experienced some form of intimate partner violence in the past 12 months, with 13 percent having experienced at least two different forms of violence. Significant positive associations with all forms of violence were found for lack of completion of primary school, history of violence exposure in women's families of origin either through witnessing violence between parents while growing up or direct experience of physical violence perpetrated by family members, partner's jealousy, partner's need for control, partner's history of drunkenness, and female-dominated financial decision-making. Significant positive associations were found between men's physical abuse of children at the community level and women's risk of experiencing emotional and physical violence. Neighborhood poverty and male unemployment, number of children living at home, women's attitudinal acceptance of wife beating, and male-dominated financial decision-making were additional risk factors for sexual violence. Women's economic independence was a protective factor for emotional and physical violence, while relationship quality was protective for all forms of violence and multiple victimizations.     

Reliability for grading acute rejection and airway inflammation after lung transplantation.

BACKGROUND: The Lung Rejection Study Group (LRSG) created a scheme for grading acute allograft rejection in 1990 and then revised it in 1996, but virtually no studies have evaluated the reliability of this formulation. This investigation assessed the reliability of the current LRSG system by determining inter- and intrareader agreement for grading transbronchial biopsy samples from lung transplant recipients. METHODS: Biopsy samples from a cohort of 204 recipients were reviewed and classified by a single pathologist who was blinded to original interpretations. The "A" and "B" rejection grades from this contemporary review were compared with original grades by the kappa statistic. RESULTS: For "A" grading, weighted kappa was 0.65 (95% confidence interval [CI] 0.60-0.70) for interreader agreement (n = 529 specimens) and 0.65 (95% CI 0.53-0.76) for intrareader agreement (n = 97 specimens). For "B" grading, weighted kappa was 0.26 (95% CI 0.14-0.39) for interreader agreement (n = 164 specimens) and 0.33 (95% CI 0.15-0.51) for intrareader agreement (n = 58 specimens). CONCLUSIONS: On the basis of the analysis of the LRSG scheme, "A" grades exhibit very good reliability, but "B" grades have only fair reliability, and steps to improve this shortcoming should be taken.