Regulation of B Cell:T Cell Interactions: Potential Involvement of an Endogenous B Cell Sialidase

In light of the ability of B cells treated with neuraminidase to interact more effectively with T cells, the increased capacity of activated, but not small resting B cells, to interact with T cells could be associated with the level of sialylation on certain B cell surface molecules which influences the effectiveness of the physical interaction between B and T cells. The purpose of this study was to determine if activation of B cells altered sialylation via an endogenous sialidase which affected both the initial interaction between T and B cells and subsequent B cell-induced T cell proliferation. The competitive neuraminidase inhibitor, 2-deoxy-2,3-dehydro-N-acetylneuraminic acid (NeuAc2en), inhibited LPS-mediated enhancement of B cell conjugate formation with Ia-specific T cell clones as well as enhancement of their capacity to stimulate a mixed lymphocyte reaction. The addition of NeuAc2en during LPS stimulation did not affect the surface expression of Ia, LFA-1, ICAM-1 or mB7, suggesting that inhibition of LPS-mediated enhancement by the sialidase inhibitor was not due to changes in the level of expression of the major B cell adhesion or co-stimulatory molecules. Short term stimulation with phorbol myristate acetate (PMA) and ionomycin also enhanced the ability of resting B cells to form antigen specific T:B conjugates. However, activation of B cells with PMA and ionomycin or with LPS did not change the capacity of a sialic acid specific lectin to bind to the B cells, suggesting that activation was not associated with global changes in surface sialic acid content. B cell stimulation did not appear to increase the activity of the most prevalent B cell sialidase activity as measured in an in vitro assay system, suggesting that the major B cell sialidase may not be responsible for the alteration of B cell sialylation levels or the ability of activated B cells to interact more effectively with T cells. The possibility of intracellular compartmentalization of sialidase activity or that a minor B cell sialidase may play a role in the regulation of a B cells ability to interact with T cells are discussed.     

Ovarian cysts are common in premenarchal girls: a sonographic study of 101 children 2-12 years old.

Previous studies of sonograms in premenarchal girls have reported the typical ovary to be homogeneous in echogenicity, with cysts an uncommon finding, particularly in children less than 6 years old. These studies found no macrocysts (cysts greater than 9 mm in greatest length) in patients less than 11 years old. This information contradicts published pathology studies and our sonographic experience. The goal of this study was to determine the prevalence of cysts in the ovaries of premenarchal girls. The pelvic sonograms of 101 consecutive premenarchal girls between 2 and 12 years old, without known gynecologic or endocrinologic disease, were prospectively studied. One hundred fifty-five ovaries were adequately imaged in three dimensions. Ovaries were evaluated for the presence or absence of cysts (as defined by sonographic criteria), and the length of the cyst or of the largest cyst, if several were noted, was measured. Cysts were identified in 106 ovaries (68%). Cysts were seen in patients of all ages, particularly in the younger children (2-6 years old). Thirteen of the cysts, noted in 11 patients between 2 and 10 years old, were macrocysts. The typical sonographic appearance of the ovary in premenarchal girls is not homogeneous. Cysts are common in premenarchal girls between 2 and 12 years old and are the cause of the typical heterogeneous image. Macrocysts can be seen in healthy girls less than 11 years old.     

Cerebral glucose metabolism in patients with summer seasonal affective disorder.

Positron emission tomography scans of nine patients diagnosed with summer seasonal affective disorder (SSAD) were compared with scans of 45 normal control subjects to investigate differences in brain glucose metabolism. All subjects performed an auditory discrimination task beginning several minutes before injection of F-18-deoxyglucose and continuing for 30 minutes after injection. Regional glucose metabolic rates were extracted from 60 rectangular regions of interest measured in five planes selected as atlas matches from 28 total slices. Statistically significant differences between patients with SSAD and normal control subjects were found in cerebral glucose metabolic rate and also in normalized regional glucose metabolic rates in the orbital frontal cortex and in the left inferior parietal lobule.     

Integrating behavioral and social science into a public health agency: A case study of New York City

In the last century, both the health and life expectancy of Americans improved dramatically. These gains were primarily the result of advances in public health. But the approaches used may not be adequate to achieve the next level of improvements in health. Because health exists in the context of social, environmental, community, religious, political, and other spheres, ecological approaches that incorporate behavioral and social science theory and methodologies may provide the best avenue for advancing health in the 21st century. In 1999, the New York City Department of Health (NYCDOH) undertook the task of integrating behavioral and social science into its public health practice. The experience serves as a case study on the integration process at a public health agency.     

Diagnosis and evaluation of adults with attention-deficit/hyperactivity disorder.

Although some areas of adult ADHD knowledge remain unclear, there isa strong sense of how to proceed with diagnosis using current DSM-IV criteria as a guide. Thorough clinical interview, aided by the use of rating scales for current symptoms and collateral information about childhood from parents or siblings, forms the backbone of the assessment. The poor psychosocial outcomes of patients with ADHD. often a consequence of unrecognized,untreated disorder manifestation, also can serve as a diagnostic indicator. Diagnostic and symptom assessment scales also can be a significant helpin diagnosing and establishing the symptoms of ADHD in adults. It is important to remember that according to DSM-IV, the cardinal criteria for making the diagnosis are the presence of sufficient current symptoms and impairment in two realms (home, school/work, and social interactions). Accordingly, adult ADHD remains a clinical diagnosis, and the clinician-administered interview remains the cornerstone of diagnostic evaluation.     

High frequency of congenital adrenal hyperplasia (classic 11 beta-hydroxylase deficiency) among Jews from Morocco.

Steroid 11 beta-hydroxylase deficiency is relatively frequent in Israel among North African Jews. Over a 39-year period, 38 affected individuals from 25 families were diagnosed. Nineteen families came from Morocco, and in another 2, one parent came from Morocco (80% of all parents). Demographic studies showed that most of their grandparents were born in the region of the Atlas Mountains. In Israel, the overall incidence of the disorder is estimated between 1 in 30,000 to 1 in 40,000 births, but in offspring of Moroccan Jews the ratio is 1 in 5,000 to 1 in 7,000, with an allele frequency of 1 in 70 to 1 in 84 and a carrier frequency of 1 in 35 to 1 in 42. The clinical expression is characterized by a wide range of variability in the signs of androgen and mineralocorticoid excess. Virilization in the female ranged from enlarged clitoris in the mildest forms, to markedly hypertrophied clitoris with penile urethra and fused labial-scrotal folds in the most severe forms. Hypertension causing vascular accidents and death was observed in both severe and mildly virilized patients, whereas masculinized females were sometimes normotensive. Based on historical evidence, the origin of the ancestors, and the onomastic analysis of the families surnames, we propose that the mutation of 11 beta-hydroxylase deficiency in Jews from Morocco may have originated in either the ancient Jewish settlers or the native Berber tribes who lived in the region of the Atlas Mountains in the southern region of Morocco before the destruction of the Second Temple by the Romans, in the year 70 C.E.     

The prognostic significance of glial fibrillary acidic protein staining in medulloblastoma

Histologic and immunohistochemical properties of 53 medulloblastomas were analyzed with regard to clinical features and survival rate. No correlation was found between survival rate and histologic features of the tumor, such as desmoplastic reaction, number of mitoses, hemorrhages, necrosis, endothelial proliferation, glomerular arrangement, calcifications, rosettes, or oligodendroglial cells. However 82% of the patients with positive glial fibrillary acidic protein (GFAP) staining in numerous tumor cells survived more than 5 years; only 30% survived that long if their tumor cells were GFAP negative (P = 0.0093). This significant difference was not related to the mode of therapeutic protocol used. The authors suggest that GFAP staining may be a useful prognostic tool in medulloblastoma.     

Informed consent policies governing medical students' interactions with patients

When medical students become involved in patient care, concerns are raised that have ethical and possibly legal implications. In order to determine compliance with the guidelines of the U.S. government and the Joint Committee on Accreditation of Hospitals pertaining to informed consent, the authors conducted a study of hospital administrators, medical school department chairpersons, and medical school deans (with response rates ranging from 82.3 to 95.1 percent) concerning policies on student involvement in patient care. The results show that only 37.5 percent of all responding teaching hospitals specifically informed patients that students would be involved in care. Only 51 percent of the responding medical schools that specifically gave their students instruction or guidance on initial patient interaction as a matter of policy insisted that their students introduce themselves as students and clarify their role in patient care. The authors conclude that medical educators' compliance with the ethical requirements of informed consent is incomplete.