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.     

Menstrual cycle and gonadal steroid effects on symptomatic hyperammonaemia of urea-cycle-based and idiopathic aetiologies

Summary We report two female patients, one with a known inborn error of ureagenesis and the other of unknown cause, in whom recurrent, transient episodes of severe hyperammonaemia increased in frequency and severity with sexual maturity and parturition. Both responded to ovarian steroids administered continuously to suppress ovulation and menstruation, and ultimately to simple hysterectomy. These studies suggest a new therapeutic approach to defective ureagenesis in female patients and a relationship between ammonia production or disposal and the menstrual cycle.     

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.      

Thymus involution in the acquired immunodeficiency syndrome

Acquired immunodeficiency syndrome (AIDS) is a severe disorder of unknown etiology and pathogenesis, predominantly affecting homosexual males and other high-risk groups and characterized by profound alterations in T-lymphocyte function. The authors have examined thymus tissue from 14 patients who died of AIDS and compared the results with findings in five control groups: healthy age-matched controls, elderly individuals, patients with chronic or debilitating illnesses other than AIDS, infants with conditions causing "stress atrophy," and patients with myasthenia gravis. The AIDS group included 11 homosexual males, 1 Haitian, 1 homosexual who was also a drug abuser, and a 10-month-old infant believed to have contracted AIDS following blood transfusion. All the AIDS cases showed marked thymus involution with severe depletion of both lymphocytes and epithelial elements. The latter component consisted primarily of thin cords and nests of primitive-appearing epithelial cells that could be defined by positive immunohistochemical staining for keratin. Many cases showed a variable plasma cell infiltration, and the majority exhibited distinct vascular changes in the form of hyalinization and/or onion-skin patterns, primarily in the adventitia. Most striking of all was the marked paucity of Hassall's corpuscles; four patients had none at all, while in the other ten patients all the Hassall's corpuscles were calcified. These changes were far more extensive than those seen in any of the control groups, which retained most of their complement of Hassall's corpuscles even in the face of marked overall involution. The physiologic function of Hassall's corpuscles is not known, but recent immunohistochemical studies have implicated them in the synthesis of "facteur thymique serique" (FTS, thymulin) and other thymic hormones known to play a role in regulating T-helper and suppressor cell activity. It is conceivable that the extensive destruction of Hassall's corpuscles observed in AIDS may be a crucial element in the pathogenesis of this syndrome.     

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.     

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.