Intratemporal vascular tumors: detection with CT and MR imaging

The diagnostic contributions of computed tomography (CT) and magnetic resonance (MR) imaging were compared in 12 patients with benign intratemporal vascular tumors (hemangioma or vascular malformation). The tumors included six in the internal acoustic canal and six in the geniculate ganglion region. Clinical and histologic correlations were made. Two of the six patients with tumors in the internal acoustic canal underwent CT, and both required gas cisternography to show the tumor. Five patients in that group underwent MR imaging, and all five studies showed the tumor. All six patients with geniculate ganglion tumors underwent CT. Results in one study were questionable, and five showed the tumor. Five patients in this group underwent MR imaging, but the MR findings were positive in only two cases. MR imaging should therefore be performed before CT in the evaluation of facial nerve dysfunction, as it demonstrated all tumors in the internal acoustic canal and some in the geniculate ganglion region. If MR findings are negative, CT should then be performed to rule out a possible geniculate ganglion lesion.     

Blood donation behavior of Hispanics in the lower Rio Grande Valley

This study was designed to determine the blood donation behavior and attitudes of Hispanic residents of the Lower Rio Grande Valley for the purpose of developing promotional and educational approaches to enhance levels of donor participation. Personal interviews of 545 respondents were conducted in English and Spanish using quota sampling and standard intercept techniques at lower- and middle-income supermarkets in five cities during a payday weekend. A number of research hypotheses were established to test for demographic, behavioral, and attitudinal differences that were observed in donors and nondonors using chi-square analysis and multiple discriminant analysis. After analyzing the difference between Hispanics and non-Hispanics for blood donation rates, all non-Hispanics were eliminated from analysis, and the remaining 419 Hispanics were evaluated on the basis of their donor behavior. Donation among Hispanics was most likely to be by better- educated, English-speaking, higher-job-status individuals who had participated in a blood donation drive. Donors tend to have parent(s) who were donors, and they were also more likely to carry an organ donor card. Donors were found to vary in their behaviors as well as their attitudes and beliefs. Perceptions of a lack of safety in donating, the risk of contracting acquired immune deficiency syndrome, and the financial motivation of donors were most pronounced among Hispanics, which indicated a need for improved education on these issues.     

Fatal craniocervical necrotizing fasciitis in an immunocompetent patient: A case report and literature review

Background. Craniocervical necrotizing fasciitis (CCNF) is a rapidly progressive, severe bacterial infection of the superficial fascial planes of the head and neck. Group A beta–hemolytic Streptococcus, staphylococcus aureus, and obligate anaerobic bacteria are common pathogens. The disease usually results from a dental source or facial trauma. Extensive fascial necrosis and severe systemic toxicity are common manifestations of CCNF. Recently the lay press has referred to necrotizing fasciitis in several articles about “flesh eating” bacteria, which have resulted in several deaths. Methods. We report the first case of a fatality in an otherwise immunocompetent patient. The patient was a 66-year-old black man with no identifiable source of infection and no history or evidence of immunocompromising disorders. Results. Despite aggressive surgical debridement and broad-spectrum antibiotic coverage, he died 30 hours after admission from multisystem organ failure secondary to overwhelming sepsis. Conclusion. Treatment consists of early recognition of CCNF combined with aggressive surgical debridement and drainage of the involved necrotic fascia and tissue along with broad-spectrum intravenous antibiotic coverage. Although 11 other fatal cases of CCNF have been previously reported, all had an underlying medical problem which created an immunocompromised state, usually diabetes mellitus or chronic alcoholism. We present a case report and literature review along with a discussion of the related anatomy. © 1995 Jons Wiley & Sons, Inc.     

WSJM, a simple chemically defined medium for growth of Neisseria gonorrhoeae

The growth requirements of 135 clinical isolates of Neisseria gonorrhoeae and six American Type Culture Collection reference strains were examined by using a simple chemically defined medium known as Wong-Shockley-Johnston medium, WSJM. The simple liquid medium supported growth of gonococci from an inoculum of 2 X 10(6) colony-forming units ml-1 and yielded 10(10) colony-forming units ml-1 in 10 h in the absence of CO2. Scale-up experiments with the complete medium yielded 5 to 10 g, wet weight, of cells per liter. The complete medium was stable upon storage at 5 degrees C and after lyophilization.     

Human leukocyte antigen matching and fetal loss: results of a 10 year prospective study

The role that maternal and fetal human leukocyte antigen (HLA) genes play in pregnancy is unknown, but it has been suggested that fetuses whose HLA alleles do not differ from maternal alleles (i.e. histocompatible fetuses) are more likely to be aborted than fetuses with HLA alleles that differ from maternal alleles (i.e. histoincompatible fetuses). To elucidate the role of HLA compatibility in pregnancy, we tested the hypothesis that couples who match for HLA alleles or haplotypes would have reduced fertility because only these couples could produce histocompatible fetuses. We conducted a 10 year prospective study of HLA matching and pregnancy outcome in 111 Hutterite couples, providing information on 251 pregnancies. A logistic regression analysis was performed to determine the effects of HLA matching at HLA regions and loci on pregnancy outcome (fetal loss versus delivery). Significantly increased fetal loss rates were observed among couples matching for the entire 16-locus haplotype (P = 0.002). Among the individual loci, loss rates were increased among couples matching for HLA-B (P = 0.019), HLA-C (P = 0.033) and the complement component, C4 (P = 0.043). We interpret these results as evidence that matching for the entire 16-locus haplotype and/or alleles at an HLA-B-linked locus confers significant risk for fetal loss.      

Marrow regeneration after mechanical depletion

The origin of marrow regeneration after mechanical depletion was reinvestigated in mouse chimeras. The results were compatible with the local origin of stem cells from remnants of incompletely removed marrow, but not with their origin from a common precursor of both bone and hemopoietic cell lines. In transplanted femurs depleted by a modified technique of in vivo evacuation of marrow, hemopoietic regeneration failed to occur. The presence of hemopoietic stem cells in the Haversian canals was thus excluded. The demonstration of ample hemopoiesis with minimal bone formation in nondepleted controls in which bone marrow initially became necrotic provided new evidence that osteogenesis was not a prerequisite of hemopoietic regeneration.     

Statistical considerations for crosssectional data relating to tracheal reconstruction over time

Complementary statistical analyses are performed on data concerning tracheal reconstruction in rats. The principal response criterion is vessel area as defined by the area of a graft onto the trachea covered by blood vessels. Postoperatively, this vessel area changes in a nonlinear fashion over time. Starting at 0% immediately postoperation, the vessel area increases to a peak and then sharply decreases to a certain level at which it remains. A total of 64 independently observed cross-sectional pairs (postop day, vessel area) are distributed among four treated groups. Analysis consists of two-way analysis of variance and piecewise linear regression under the usual assumptions of normality and variance homogeneity. Other analyses that relax these assumptions are also considered; treatment differences are established by nonparametric tests, and a quasi-likelihood analysis of the piecewise linear regression model is applied under the assumption of a binomial-like variance function. The resulting fit of the normal-theory-based piecewise linear model is compared to that of a nonlinear model whose shape is that of a gamma function integrand.     

First-time anterior shoulder dislocations: should they be arthroscopically stabilised?

The glenohumeral joint is inherently unstable because the large humeral head articulates with the small shadow glenoid fossa. Traumatic anterior dislocation of the shoulder is a relatively common athletic injury, and the high frequency of recurrent instability in young athletes after shoulder dislocation is discouraging to both the patient and the treating physician. Management of primary traumatic shoulder dislocation remains controversial. Traditionally, treatment involves initial immobilisation for 4–6 weeks, followed by functional rehabilitation. However, in view of the high recurrence rates associated with this traditional approach, there has been an escalating interest in determining whether immediate surgical intervention can lower the rate of recurrent shoulder dislocation, improving the patient’s quality of life. This review article aims to provide an overview of the nature and pathogenesis of first-time primary anterior shoulder dislocations, the widely accepted management modalities, and the efficacy of primary surgical intervention in first-time primary anterior shoulder dislocations.     

Deviations from Hardy-Weinberg Frequencies Caused by Assortative Mating in Hybrid Populations

The conventional formulas for genotype frequencies in a hybrid population H produced by interbreeding from ancestral populations P₁ and P₂ involve only one hybrid parameter M, equal to the fraction of alleles derived from P₂. For the one-parameter model to be accurate, all individuals of H must have probabilities for alleles determined by one and the same M. When H contains subpopulations that have different values of M, the correct genotype frequencies can be predicted by use of two parameters: (i) M_H, the average of M for all individuals of H and (ii) eta_H, defined like the eta devised by C. A. B. Smith for testing the Hardy-Weinberg Law and computed with a formula like G. R. Price's eta, which involves assortative mating covariance—in this case for the M values of the parents of H. If parents of H have equal average M values for males and females, and mate at random, eta_H vanishes. For perfect assortative mating, eta_H is the variance of M for H. As for Smith's eta, eta_H provides a test of fit of prediction to observed that is sensitive to signs of deviations. Using eta_H with T. E. Reed's data for Gm in Oakland, California Negroes, his one-parameter fit (“good” by his chi-square test) is significantly rejected (P = 0.04). A simultaneous good fit of Reed's Gm data and his Duffy data results (chi-square, 1 df = 0.88, P > 0.30) from the use of previously published values of 0.23 and 0.047 for M_H and eta_H. It is concluded that Reed's conclusion that these values were in error is itself in error, as is also his view that differences between M values from different genes and deviations from frequencies expected within genes are not likely to give significant information about variance of M.