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Biomedical subjects

J Jordan

Publications and source records attributed to J Jordan.

At least 73 records · Page 4Linked to original sources
PubMed2000

Innovations in section 1115 demonstrations.

This article discusses how States have taken advantage of the flexibility afforded under section 1115 research and demonstration authority. It describes how States have used Section 1115 authority to develop innovations in outreach and enrollment, eligibility requirements, access, benefits, quality assurance, payment, safety net providers, and special needs populations. It concludes by discussing the future challenges that all the players in Medicaid demonstration projects are facing.

Diffusion of Innovation↗
PubMed1999

Nitric oxide modulates HIV-1 replication.

Although nitric oxide (NO) production is increased in HIV-1-infected patients, and NO is known to inhibit the replication of several viruses, very little is known about the effects of NO on HIV-1 replication. In the present studies, we find that S-nitrosothiols (RSNOs), a class of NO donor compounds present in the human circulatory system, inhibit HIV-1 replication in acutely infected human peripheral blood mononuclear cells (PBMCs) and have an additive inhibitory effect on HIV-1 replication in combination with 3'-azido-3'-deoxythymidylate (AZT). RSNOs inhibit HIV-1 replication in acutely infected PBMCs at a step in the viral replicative cycle after reverse transcription, but before or during viral protein expression through a cGMP-independent mechanism. In the latently infected U1 cell line, NO donor compounds and intracellular NO production stimulate HIV-1 reactivation. These studies suggest that NO both inhibits HIV-1 replication in acutely infected cells and stimulates HIV-1 reactivation in chronically infected cells. Thus, NO may have a physiologic role in HIV-1 replication, and NO donor compounds, which have been used for decades in the treatment of coronary artery disease with limited toxicity, might be useful in the treatment of HIV-1 disease by inhibiting acute infection, reactivating latent virus, or both.

Adult↗
PubMed1999

Rat osteotesticular phosphatase gene (Esp): genomic structure and chromosome location.

Osteotesticular phosphatase (OST-PTPase) is a class III receptor-type tyrosine phosphatase (RPTPase). It has 10 tandem fibronectin III-like (FN-III) repeats in the extracellular region and two phosphatase domains in the intracellular region. The expression of the rat OST-PTPase gene, Esp, is restricted to osteoblasts and Sertoli cells, and the transcript level in osteoblasts is highly up-regulated by parathyroid hormone and cAMP treatment. We report here the cloning and characterization of the rat Esp gene, including a 2.9-kb 5' flanking region sequence. Two potential binding sites for Osf2/Cbfa1, an osteoblast-specific transcription factor, are present in the promoter. Esp is composed of 35 exons, but spans merely 20 kb, making it the most compact RPTPase gene identified. Each FN-III repeat is encoded by a single exon flanked with phase 1 introns. Two phosphatase domains are encoded by 16 exons in a genomic organization similar to those in RPRPalpha, RPTPgamma, and Ptprc genes. Esp was mapped by fluorescence in situ hybridization to rat chromosome 13q1. These results represent the first genomic structure of a mammalian class III RPTPase gene.

Animals↗
PubMed1999

Effects of standing on cerebrovascular resistance in patients with idiopathic orthostatic intolerance.

PURPOSE: Patients with idiopathic orthostatic intolerance often have debilitating symptoms on standing that are suggestive of cerebral hypoperfusion despite the absence of orthostatic hypotension. SUBJECTS AND METHODS: We evaluated the effects of graded head-up tilt on cerebral blood flow as determined by transcranial Doppler measurements in 10 patients with idiopathic orthostatic intolerance (nine women, one man, 22 to 47 years) and nine age- and sex-matched control subjects. RESULTS: In patients, mean (+/- SD) arterial pressure at 0 degrees head-up tilt was 90 +/- 11 mm Hg and was well maintained at all tilt angles (90 +/- 11 mm Hg at 75 degrees). In controls, mean arterial pressure was 85 +/- 7 mm Hg at 0 degrees and 82 +/- 11 mm Hg at 75 degrees head-up tilt. There was a substantial decrease in peak velocity with increasing tilt angle in patients (28% +/- 10%) but not in controls (10% +/- 10% at 75 degrees, P <0.001). Similarly, mean velocity decreased 26% +/- 13% in patients and 12% +/- 11% in controls (P = 0.01). With increasing head-up tilt, patients had a significantly greater increase in regional cerebrovascular resistance than controls. CONCLUSIONS: In patients with idiopathic orthostatic intolerance, peak and mean middle cerebral artery blood flow velocity decreased in response to head-up tilt despite well sustained arterial blood pressure. These observations indicate that in this group of patients, regulation of cerebrovascular tone may be impaired and might therefore be a target for therapeutic interventions.

Adult↗
PubMed1999

Interaction of genetic predisposition and environmental factors in the pathogenesis of idiopathic orthostatic intolerance.

BACKGROUND: The hemodynamic and autonomic abnormalities in idiopathic orthostatic intolerance (IOI) have been studied extensively. However, the mechanisms underlying these abnormalities are not understood. If genetic predisposition were important in the pathogenesis of IOI, monozygotic twins of patients with IOI should have similar hemodynamic and autonomic abnormalities. METHODS: We studied two patients with IOI and their identical twins. Both siblings in the first twin pair had orthostatic symptoms, significant orthostatic tachycardia, increased plasma norepinephrine levels with standing, and a greater than normal decrease in systolic blood pressure with trimethaphan infusion. RESULTS: Both siblings had a normal response of plasma renin activity to upright posture. In the second twin pair, only one sibling had symptoms of orthostatic intolerance, an orthostatic tachycardia, and raised plasma catecholamines with standing. The affected sibling had inappropriately low plasma renin activity with standing and was 8-fold more sensitive to the pressor effect of phenylephrine than the unaffected sibling. CONCLUSIONS: We conclude that in some patients, IOI seems to be strongly influenced by genetic factors. In others, however, IOI may be mainly caused by nongenetic factors. These findings suggest that IOI is heterogenous, and that both genetic and environmental factors contribute individually or collectively to create the IOI phenotype.

Adult↗
PubMed1999

Regulation of MAC-1 (CD11b/CD18) expression on circulating granulocytes in endurance runners.

PURPOSE: We tested the hypothesis that degranulation of granulocytes and upregulation of the granulocyte integrin MA-1 (CD11b/CD18) are related to exercise duration and/or intensity. We also investigated whether or not the expression of MAC-1 would be influenced by body temperature or dehydration. Moreover, we tested the hypothesis that changes in leukocyte counts and changes in MAC1 expression with endurance exercise are independently regulated. METHODS: In eight amateur runners, MAC-1 (CD11b/CD18) surface expression on granulocytes was determined by fluorescent antibody cell sorting, before and after an incremental maximal treadmill test, a moderate 3-h run, and a competitive marathon race. RESULTS: Expression CD11b on granulocytes was increased by 10+/-9.6% (P < 0.05) after the maximal treadmill test and by 84+/-76% (P < 0.01) after the marathon run. There was no change in CD11b expression after the moderate 3-h run. CD18 expression was not significantly changed after any of the exercise protocols. CONCLUSION: Expression of CD11b on granulocytes is increased with intense endurance exercise, either incremental maximal treadmill testing or competitive marathon running, but not in moderate endurance training. Thus, exhaustive exercise may be one mechanism for the upregulation of integrin adhesive receptors on granulocytes. This phenomenon could be in part responsible for increased adhesion of granulocytes to endothelial cells and could facilitate tissue infiltration after endurance exercise.

Adult↗
PubMed1999

Clinical governance: culture, leadership and power--the key to changing attitudes and behaviours in trusts.

Clinical governance places for legal duty for quality on Trust chief executives. The article deals with how chief executives can overcome the cultural and behavioural obstacles to change which impede the journey to developing effective structures for clinical governance. To establish effective structures for clinical governance, chief executives will need to address these features of organisational life--culture, power and leadership. The article seeks to provide practical ways in which they can do this.

Governing Board↗
PubMed1999

An audit of standards and quality in a teaching hospital colposcopy clinic.

The National Health Service Cervical Screening Programme has issued minimum standards for a colposcopy service that facilitates audit. We have looked at the performance of a teaching hospital colposcopy service by analysing the case notes of 639 women who underwent large loop excision of the transformation zone over a nine-month period in 1995. We found delays in patient assessment and communication of results. There was overtreatment, particularly at first visit, and an excessive number of treatments were performed under general anaesthesia. A worrying number of women failed to have a follow up smear performed, but in those that did we found a reassuring treatment success rate. Our findings led to changes in the structure and functioning of the colposcopy clinic that should improve the detection of significant disease and improve the timeliness of diagnosis and the speed with which we communicate results.

Colposcopy↗
PubMed1999

Mycoplasma pneumoniae protein P30 is required for cytadherence and associated with proper cell development.

The attachment organelle of Mycoplasma pneumoniae is a polar, tapered cell extension containing an intracytoplasmic, electron-dense core. This terminal structure is the leading end in gliding motility, and its duplication is thought to precede cell division, raising the possibility that mutations affecting cytadherence also confer a defect in motility or cell development. Mycoplasma surface protein P30 is associated with the attachment organelle, and P30 mutants II-3 and II-7 do not cytadhere. In this study, the recombinant wild-type but not the mutant II-3 p30 allele restored cytadherence when transformed into P30 mutants by recombinant transposon delivery. The mutations associated with loss of P30 in mutant II-3 and reacquisition of P30 in cytadhering revertants thereof were identified by nucleotide sequencing of the p30 gene. Morphological abnormalities that included ovoid or multilobed cells having a poorly defined tip structure were associated with loss of P30. Digital image analysis confirmed quantitatively the morphological differences noted visually. Transformation of the P30 mutants with the wild-type p30 allele restored a normal morphology, as determined both visually and by digital image analysis, suggesting that P30 plays a role in mycoplasma cell development. Finally, the P30 mutants localized the adhesin protein P1 to the terminal organelle, indicating that P30 is not involved in P1 trafficking but may be required for its receptor-binding function.

Adhesins, Bacterial↗
PubMed1999

Serum and tissue antioxidant capacity in cervical intraepithelial neoplasia investigated using an enhanced chemiluminescent reaction.

Depleted antioxidant defence has been implicated in the pathogenesis of cervical neoplasia. We determined the systemic and local antioxidant status of women with this condition. Thirty-four women with varying grades of cervical intraepithelial neoplasia, 25 patients who had been treated successfully with diathermy loop excision, and 56 women who had no evidence of cervical abnormality acted as controls. Total antioxidant capacity of serum and protein-free serum, and of neat and protein-free homogenized cervical punch biopsies were determined using enhanced chemiluminescence. Mean serum antioxidant capacity of patients with current neoplasia and treated patients was not significantly different from that of controls. However, mean antioxidant capacity of homogenized cervical tissue from women with neoplasia was significantly lower than control means (P < 0.005), while results for treated patients were intermediate between those from diseased and normal samples (P < 0.05). The enhanced chemiluminescence technique has potential as a suitable method for measuring total antioxidant capacity of cervical tissue, and warrants further investigations using other tissue types. Significant antioxidant depletion in cervical intra-epithelial neoplasia appears to be confined to the local cervical mucosa.

Adult↗
PubMed1999

Contrasting effects of vasodilators on blood pressure and sodium balance in the hypertension of autonomic failure.

Supine hypertension, which is very common in patients with autonomic failure, limits the use of pressor agents and induces nighttime natriuresis. In 13 patients with severe orthostatic hypotension due to autonomic failure (7 women, 6 men, 72 +/- 3 yr) and supine hypertension, the effect of 30 mg nifedipine (n = 10) and 0.025 to 0.2 mg/h nitroglycerin patch (n = 11) on supine BP, renal sodium handling, and orthostatic tolerance was determined. Medications were given at 8 p.m.; patients stood up at 8 a.m. Nitroglycerin was removed at 6 a.m. Compared with placebo, nifedipine and nitroglycerin decreased systolic BP during the night by a maximum of 37 +/- 9 and 36 +/- 10 mmHg, respectively (P < 0.01). At 8 a.m., supine systolic BP was 23 +/- 7 mmHg lower with nifedipine than with placebo (P < 0.05), but was similar with nitroglycerin and placebo. Sodium excretion during the night was not reduced with nitroglycerin (0.13 +/- 0.02 mmol/mg creatinine [Cr] versus 0.15 +/- 0.03 mmol/mg Cr with placebo), but it was increased with nifedipine (0.35 +/- 0.06 mmol/mg Cr versus 0.13 +/- 0.02 mmol/mg Cr with placebo, P < 0.05). Nifedipine but not nitroglycerin worsened orthostatic hypotension in the morning. It is concluded that nifedipine and transdermal nitroglycerin are effective in controlling supine hypertension in patients with autonomic failure. However, nifedipine has a prolonged depressor effect and worsens orthostatic hypotension in the morning. The decrease in pressure natriuresis that would be expected with the substantial decrease in BP obtained with nitroglycerin and nifedipine may be offset by a direct effect of both drugs on renal sodium handling.

Aged↗
PubMed1999

Acute effect of ephedrine on 24-h energy balance.

Ephedrine is used to help achieve weight control. Data on its true efficacy and mechanisms in altering energy balance in human subjects are limited. We aimed to determine the acute effect of ephedrine on 24-h energy expenditure, mechanical work and urinary catecholamines in a double-blind, randomized, placebo-controlled, two-period crossover study. Ten healthy volunteers were given ephedrine (50 mg) or placebo thrice daily during each of two 24-h periods (ephedrine and placebo) in a whole-room indirect calorimeter, which accurately measures minute-by-minute energy expenditure and mechanical work. Measurements were taken of 24-h energy expenditure, mechanical work, urinary catecholamines and binding of (+/-)ephedrine in vitro to human beta1-, beta2- and beta3-adrenoreceptors. Twenty-four-hour energy expenditure was 3.6% greater (8965+/-1301 versus 8648+/-1347 kJ, P<0.05) with ephedrine than with placebo, but mechanical work was not different between the ephedrine and placebo periods. Noradrenaline excretion was lower with ephedrine (0.032+/-0.011 microg/mg creatinine) compared with placebo (0.044+/-0.012 microg/mg creatinine) (P<0.05). (+/-)Ephedrine is a relatively weak partial agonist of human beta1- and beta2-adrenoreceptors, and had no detectable activity at human beta3-adrenoreceptors. Ephedrine (50 mg thrice daily) modestly increases energy expenditure in normal human subjects. A lack of binding of ephedrine to beta3-adrenoreceptors and the observed decrease in urinary noradrenaline during ephedrine treatment suggest that the thermogenic effect of ephedrine results from direct beta1-/beta2-adrenoreceptor agonism. An indirect beta3-adrenergic effect through the release of noradrenaline seems unlikely as urinary noradrenaline decreased significantly with ephedrine.

Adrenergic alpha-Agonists↗
PubMed1999

[Histiocytosis X (Langerhans cell histiocytosis) of temporal bone. Role of scintigraphy in disease progress evaluation].

The authors present a case report of a 7-year-old girl with Langerhans cell histiocytosis of temporal bone. Edema and bone destruction involved zygomatic process of temporal bone and temporal fossa without ear occupation. The role of picturing diagnosis in evaluation of lesion extent with special importance of scintigraphy is discussed. Treatment methods of Langerhans cell histiocytosis lesions in temporal bone are presented. In our case locally Depo-Medrol injection was given and radiation was left as last resort management.

Child↗
PubMed1999

[Adenolymphoma (Warthin's tumor) of the larynx: coexistence with the bilateral laryngocele. Contribution to differential diagnosis with oncocytic papillary cystadenoma].

Adenolymphoma is a benign monomorphic lesion composed of epithelial tissue. Usually it is found in parotid gland; however, its laryngeal occurrence was rarely described. Extraparotid Warthin's tumour as scanty lymphatic tissue. In cases when there is no lymphatic tissue in subepithelial layer it is called oncocytic cystadenoma. The authors describe the case of bifocal adenolymphoma in bilateral laryngocoele and indicate classification difficulties of oncocytic lesions in the larynx.

Adenolymphoma↗