Validation in the sheep of an ultrasound velocity dilution technique for haemodialysis graft flow

BACKGROUND: A simple, rapid, inexpensive method for measuring the flow in a patient's vascular access would permit routine monitoring during haemodialysis, and hence provide information of access graft deterioration sufficiently early to increase the success of minimally invasive remedial procedures. This paper reports the validation of such a method in animals. METHODS: A PTFE graft was implanted in sheep between the carotid artery and the jugular vein. While the sheep was under general anaesthesia and on an haemodialysis circuit, ultrasound velocity in its blood was perturbed by the injection of a 5-10 ml bolus of isotonic NaCl. The pump tubing flow was measured by a transit-time blood flow meter. This flow was combined with the areas of perturbation generated by the injection before and after mixing in the access flow to estimate graft flow. The calculated graft flow was compared to flow measured directly by a transit-time probe on the same carotid artery. RESULTS: Over a 10-fold range, 120-1260 ml/min, graft flow measured by ultrasound velocity dilution agreed well with graft flow measured directly with a scatter of 76 ml/min about the regression line. CONCLUSION: Ultrasound velocity dilution provides a method for measuring flow in the graft accurate enough for clinical evaluation of patients on dialysis.      

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.     

Characterization of cognitive functioning in a subgroup of children with congenital HIV infection.

The cognitive status of 12 clinically stable children with congenital HIV infection, nine of whom were neurologically impaired, age three to nine years, was assessed using the Kaufman ABC test. Seven of the children had ARC; five were diagnosed as having AIDS. The same children were evaluated by standard neurologic examinations with Characterization of tone and fine motor functioning. Two were diagnosed as being mildly retarded; six were borderline; and four tested as being of average intelligence. Visual-spatial perceptual based functioning was found to be more impaired than were abstract reasoning and verbally mediated skills in six (50%) of the patients. This pattern of impaired information processing was found irrespective of overall cognitive status. On neurological and physiatric examination abnormal developmental histories were obtained, or poor fine motor coordination, abnormal tone and gait, and impaired rapidly alternating movements were found in 9 of the 12 subjects. These findings suggest selective impairment in distinct areas of neurologic and neuropsychological functioning during stable phases of HIV infection in a select group of children. These patterns appear to persist over time. They differ from the clustering of impaired skills seen in children of comparable socio-cultural backgrounds without HIV infection. Similarities in functioning are noted between this subgroup of children with AIDS and ARC and comparable groups with cerebral palsy.