Allele frequencies of nine STR loci of Jewish and Arab populations in Israel

DNA typing of nine short tandem repeat (STR) loci was carried out on unrelated Israeli Jewish and Arab individuals. All loci were highly polymorphic and the distribution of the obtained genotypes did not deviate from Hardy-Weinberg equilibrium. A comparison between Jewish and Arab population data revealed statistically significant differences in allele frequency distributions for some of the loci. The results presented in this study enable the use of these nine STR loci for forensic, identification and paternity cases in the Jewish and the Arab populations of Israel.

HIV-infected American Indians/Alaska natives in the Western United States

OBJECTIVE

We sought to describe HIV-infected American Indians/Alaska Natives (AI/ AN) in the western United States.

DESIGN

One hundred fifty-one Al/AN and 11,344 non-AI/AN HIV-infected patients in Seattle, Denver, and Los Angeles were followed by medical record review from January 1989 through June 1998 for the Adult/Adolescent Spectrum of HIV-related Diseases study.

METHODS

Bivariate and multivariate statistical analyses comparing HIV-infected Al/AN and non-AI/AN were performed.

RESULTS

There were 103 (68%) male and 48 (32%) female Al/AN patients, while non-Al/AN patients were 86% male and 14% female (P<.001). The median age among AI/ AN was 32 years vs. 34 years among non-AI/AN (P = .05). Male Al/AN were more likely than male non-AI/AN to report the dual risks of having sex with men and injection drug use (32% vs. 14%; P<.001) compared with other HIV risks. Median CD4 cell counts were higher in Al/AN than in non-AI/AN (P< or =.001). AI/AN were more likely to be diagnosed with an acute sexually transmitted disease (STD) than were non-AI/AN (11% vs. 4%, P<.001). Five (6%) of AI/AN with AIDS had active pulmonary tuberculosis (TB) compared with 132 (2%) of non-AI/AN with AIDS (P = .02). While 52% of Al/AN and 44% of non-AI/AN had a psychiatric illness (P = .04), and 13% of AI/AN, and 6% of non-AI/ AN had suicidal ideation (P<.001), these associations became non-significant in analyses stratified by alcohol and drug use (P>.05). In adjusted models, survival and progression to opportunistic infection or CD4 cell count less than 200/mm3 did not significantly differ between Al/AN and non-AI/AN.

CONCLUSIONS

HIV-infected AI/AN were younger than non-AI/AN, and a greater proportion of Al/AN were women relative to non-AI/AN. AI/AN were more likely to be diagnosed with STDs and TB. In adjusted models, their risks of death and developing AIDS did not significantly differ from those of non-AI/AN.

Drosophila-raf acts to elaborate dorsoventral pattern in the ectoderm of developing embryos

In the early Drosophila embryo the activity of the EGF-receptor (Egfr) is required to instruct cells to adopt a ventral neuroectodermal fate. Using a gain-of-function mutation we showed that D-raf acts to transmit this and other late-acting embryonic Egfr signals. A novel role for D-raf was also identified in lateral cell development using partial loss-of-function D-raf mutations. Thus, we provide evidence that zygotic D-raf acts to specify cell fates in two distinct pathways that generate dorsoventral pattern within the ectoderm. These functional requirements for D-raf activity occur subsequent to its maternal role in organizing the anterioposterior axis. The consequences of eliminating key D-raf regulatory domains and specific serine residues in the transmission of Egfr and lateral epidermal signals were also addressed here.

Pigmented villonodular synovitis following arthroscopic laser surgery of the knee

We report a case of a nodular variant of pigmented villonodular synovitis of the knee that developed after an arthroscopic lateral release of the synovium by laser for an unrelated condition. This case, the first reported case of pigmented villonodular synovitis following laser treatment, lends weight to the etiological association with the pathological processes of the response to trauma.

The effect of CD28/B7 blockade on alloreactive T and B cells after liver cell transplantation

BACKGROUND

Hepatocyte cell lines are beginning to be developed as universal donors for isolated liver cell transplantation, which is a less invasive method than orthotopic liver transplantation for treatment of metabolic liver disease. The immune response to isolated liver cell transplantation and its modification by costimulatory blockade are as yet not well delineated.

METHODS

Adenovirus expressing CTLA4Ig was used to study blockade of the costimulatory CD28/B7 pathway in murine models of hepatocyte transplantation, and the effects on alloreactive T and B cells were studied.

RESULTS

CTLA4Ig delayed rejection of subcutaneously administered C57L-derived murine hepatoma cells in CBA/J recipients for >50 days. Activation and cytokine secretion by allospecific CD4+ and CD8+ T cells were initially blocked by CTLA4Ig; delayed rejection was associated with tumor infiltration by CD8+ T cells that did not secrete interferon-gamma. CTLA4Ig failed to block transplant rejection in primed mice, indicating that memory effector T cells were resistant to its action. In contrast, CTLA4Ig suppressed both naive and memory alloreactive B cells. High levels of CTLA4Ig mediated acceptance of hepatoma cells delivered directly into the spleen. However, isolated primary C57BL/6 mouse hepatocytes delivered into the spleen were rejected with only moderately delayed kinetics.

CONCLUSIONS

Transplant antigenicity, transplant site, and CTLA4Ig dose all affected the survival of transplanted liver cells. CD8+ T cells are significant mediators of hepatocyte transplant rejection and are relatively resistant to costimulatory blockade with CTLA4Ig. Strategies to specifically antagonize CD8+ T cells or to modulate MHC class I expression in association with costimulatory blockade by CTLA4Ig may enhance the clinical feasibility of transplanting allogeneic hepatocytes.

A corticotropin releasing hormone receptor antagonist does not delay parturition in rats

OBJECTIVE

To determine the effects of CP-154, 526, a corticotropin releasing hormone (CRH) receptor antagonist, on the length of normal rat gestation.

STUDY DESIGN

Twenty-four timed-pregnant Sprague-Dawley rats were purchased for this study. The drug and placebo were administered to the animals using an osmotic pump surgically inserted in the dorsal subcutaneous space. Six animals received 6 mg/kg/day of the drug, six animals received 12 mg/kg/day of the drug and twelve animals received the placebo. The gestational period, weight of each pup and number of pups in each litter were recorded and compared in the drug group versus placebo group.

RESULTS

No difference was noted in the gestational period of the drug and placebo rats. The mean weight of pups in both the drug and placebo groups was 6.18 g. The number of pups per litter were similar in the drug and placebo groups.

CONCLUSION

Antagonism of CRH receptors in rats has no effect on the length of gestational period, pup weight or number of pups per litter. Further studies are needed to define the role of CRH and its antagonism in primate pregnancy, as has been done in sheep.

Characterization of transmembrane segments 3, 4, and 5 of MalF by mutational analysis

MalF and MalG are the cytoplasmic membrane components of the binding protein-dependent ATP binding cassette maltose transporter in Escherichia coli. They are thought to form the transport channel and are thus of critical importance for the mechanism of transport. To study the contributions of individual transmembrane segments of MalF, we isolated 27 point mutations in membrane-spanning segments 3, 4, and 5. These data complement a previous study, which described the mutagenesis of membrane-spanning segments 6, 7, and 8. While most of the isolated mutations appear to cause assembly defects, L(323)Q in helix 5 could interfere more directly with substrate specificity. The phenotypes and locations of the mutations are consistent with a previously postulated structural model of MalF.

"Room temperature" use of CHROMagar Candida

The color of colonies of 9 Candida species was examined on the chromogenic medium CHROMagar Candida incubated for 24-72 h at 25 degrees C, 30 degrees C or 37 degrees C. Colors and colony forms characteristic of C. albicans, C. dubliniensis, C. krusei and C. tropicalis were formed most rapidly and with the deepest hues at 37 degrees C. After 48 h incubation at 25 degrees C, 9 of 48 C. albicans isolates gave pink colonies instead of the green colonies characteristic for the species, and the blue-purple colony color characteristic of C. tropicalis isolates was not formed until 48 h at 25 degrees C. Incubation of the chromogenic medium at temperatures below 30 degrees C cannot be recommended for reliable presumptive identification of Candida spp., and pink colonies of C. glabrata would not be reliably distinguished from pink colonies formed by other species under any of the incubation conditions used.

Quantitative videofluoroscopic evaluation of pharyngeal function in the dog

Videofluoroscopic evaluation of both liquid barium and barium soaked kibble was performed in 11 adult, clinically normal dogs of varying breeds. Each examination was digitized and evaluated frame by frame to establish the normal timing sequence of the pharyngeal phase of swallowing. Closure of the epiglottis was considered the onset of swallowing. The time to each of the following events was recorded: (1) Maximum pharyngeal contraction, (2) Opening of the epiglottis, (3) Opening of the cranial esophageal sphincter, and (4) Closure of the cranial esophageal sphincter. These values were found to be consistent both intra and interpatient. Retrospective analysis of 3 videofluoroscopic examinations from dogs that met the subjective criteria defining cricopharyngeal achalasia was then performed. A statistically significant delay in the time to opening and closure of the cranial esophageal sphincter was found employing both liquid barium and barium soaked kibble in the dogs with cricopharyngeal achalasia.

Proton magnetic resonance spectroscopy ((1)H-MRS) of the brain following high-dose methotrexate treatment for childhood cancer

BACKGROUND

To avoid the late sequelae associated with cranial radiation therapy in childhood, intermediate- or high-dose intravenous methotrexate (HDMTX) has found increasing application as a means of preventing the development of overt central nervous system disease in childhood acute leukaemia. However, acute and chronic neurotoxicity has been described following HDMTX therapy, and the long-term intellectual outcome in children treated in this way is inadequately documented. Proton magnetic resonance spectroscopy ((1)H-MRS) of the brain is a noninvasive, quantitative way of assessing aspects of cerebral metabolism, which has not previously been applied to the study of children undergoing central nervous system directed therapy.

PROCEDURE

To evaluate the potential role of (1)H-MRS in the investigation of related neurotoxicity, 11 children who had received HDMTX (cumulative dose 6-96 g/m(2)) underwent localised (1)H-MRS, magnetic resonance imaging. Neuropsychological assessments were performed on the children who had more than 1 year of follow-up time since last methotrexate treatment. Control (1)H-MRS studies on 11 adult and 6 young volunteers were undertaken. Eight patients had spectra of adequate quality. Comparisons between (1)H-MRS metabolite ratios and normal controls were made.

RESULTS

Patients had a low choline/water ratio compared to controls (P < 0.01). No differences between patient and control NAA/water, Cr/water, Naa/Cr, and Cho/Cr ratios were seen. Overall, 3 patients had abnormal white matter changes on MRI. The mean IQ of the patients (104.1) was in the normal range.

CONCLUSIONS

It is postulated that choline depletion in the brains of these patients may reflect subclinical disturbances of myelin metabolism as a result of methotrexate therapy and may represent a possible avenue of treatment in patients with clinical chronic methotrexate-related neurotoxicity.

CTLA4Ig inhibits T cell-dependent B-cell maturation in murine systemic lupus erythematosus

Long-term administration of CTLA4Ig prevents the onset of disease in systemic lupus erythematosus-prone (SLE-prone) NZB/NZW F1 mice. To determine the mechanism of this effect, we engineered an adenovirus that expresses murine CTLA4Ig. Administration of a single high dose of this virus results in long-term expression of CTLA4Ig in the serum and absence of an immune response to the adenoviral vector. We administered Ad-CTLA4Ig to 19- to 22-week-old NZB/NZW F1 mice and evaluated the effect on anti-DNA antibody-producing B cells. We show that CTLA4Ig has a beneficial effect on murine SLE for as long as it is present in the serum. This effect is associated with decreased expansion of both the IgM and IgG autoreactive B-cell population, inhibition of immunoglobulin class switching, decreased frequency and altered pattern of somatic mutation, and a marked decrease in the numbers of activated CD4-positive T cells. In contrast, intrinsic B-cell hyperreactivity and the survival of plasma cells in the bone marrow, both of which are less dependent on T-cell help, appear to be unaffected by CTLA4Ig. High-dose CTLA4Ig did not induce permanent tolerance in this autoimmune disease model. Furthermore, although the mice survived in a conventional housing facility, treatment with Ad-CTLA4Ig was immunosuppressive.

Magnetic resonance spectroscopy in the evaluation of neurotoxicity following cranial irradiation for childhood cancer

In order to evaluate the role of proton MR spectroscopy (1H-MRS) in the diagnosis and assessment of long-term radiation-related neurotoxicity, 14 children who had received cranial irradiation for the treatment of childhood leukaemia (n = 6) or brain tumours (n = 8) underwent 1H-MRS, MRI and neuropsychological assessment. Short-term effects at 2 months following treatment were studied in a further three patients. MRI abnormalities were observed in nine patients. No statistically significant differences between patients and controls (n = 17) were seen in any of the calculated 1H-MRS metabolite ratios, in any of the three patient groups. On multivariate logistic regression analysis there was a correlation between the choline/water ratio and a low IQ. It is concluded that any systematic radiation-induced changes in the 1H MRS metabolites must be below the detection threshold of this study.