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Biomedical subjects

J Stein

Publications and source records attributed to J Stein.

At least 289 records · Page 16Linked to original sources
PubMed1993

Primary care physicians' views on access and health care reform: the situation in North Carolina.

BACKGROUND: This cross-sectional study assessed physicians' satisfaction with the current insurance-based reimbursement system and preferences for the two most frequently discussed health care reform proposals, and estimated the association between demographic and practice characteristics and attitudes toward health policy issues and reform plans. METHODS: A random sample of 300 physicians was drawn from state licensure files of general practitioners, family physicians, and pediatricians practicing in North Carolina. All sample physicians were sent a schematic outline of the two major health reform alternatives and a 1-page self-administered questionnaire to determine their attitudes toward the current health care system and their preferences for health reform alternatives. RESULTS: Sixty-nine percent of physicians responded to the survey. The responses indicated dissatisfaction with the current system and strong beliefs that access to care is inadequate in this diverse state with a large poor and rural population. Nearly one third of the physicians reported having insufficient information to choose between plans. Among physicians expressing a preference, 37% preferred managed competition, 38% preferred continuing the current system, and 25% preferred a single-payer system. CONCLUSIONS: A uniform opinion about health care policy is a thing of the past for American medicine. Because terms used in the health reform debate (especially "managed competition") are ambiguous and set in the context of an increasingly diverse medical profession, no single direction of health reform (much less a specific plan) secures widespread understanding or support from a large proportion of physicians. None of the plans will please all of the doctors all of the time.

Adult↗
PubMed1993

An inhibitor of antihemophilic factor (factor VIII) in an 18-month-old nonhemophilic child.

PURPOSE: Inhibitors of factor VIII occur in < or = 20% of severely affected patients with classic hemophilia, but are unusual in nonhemophilic individuals, and have not been reported in very young children. We treated a child with a "high-responding" inhibitor. PATIENT AND METHODS: Our patient was an 18-month-old boy who had experienced several episodes of life-threatening hemorrhage. The techniques we used to decrease production of factor VIII in our patient were prolonged small doses of alternate day corticosteroids and continued administration of factor VIII. RESULTS: We controlled the acute bleeding with porcine factor VIII or with recombinant human factor VIIa (rFVIIa). Immune tolerance was successfully achieved using a combination of corticosteroids and daily factor VIII infusions. CONCLUSIONS: Multimodal therapy aimed at inducing long-term remission, along with stop-gap measures for hemostasis, may be effective for treating children with this acquired coagulopathy.

Animals↗
PubMed1992

Simple and rapid method for determination of short-chain fatty acids in biological materials by high-performance liquid chromatography with ultraviolet detection.

A new and versatile method for the identification and quantification of short-chain fatty acids, such as formic, acetic, propionic, butyric, isobutyric, valeric, isovaleric and mercaptoacetic acids, in biological specimens by high-performance liquid chromatography is described. After sample purification by vacuum transfer and concentration by alkaline freeze-drying, the acids were measured without any further preparative step, using a sulphonated polystyrene-divinylbenzene column as stationary phase. Ultraviolet detection of the native acids was done at 214 nm. Peak resolution and reproducibility were as good as with gas chromatography. Many examples of the application of this method to a variety of biological specimens and fluids both from the rats and humans are described.

Animals↗
PubMed1992

Favorable experience with pre-emptive renal transplantation in children.

We retrospectively examined our experience with live-related donor kidney transplants in 66 children during the 7-year period 1984-1990. We compared the clinical courses of 26 children who did not receive any dialytic therapy prior to transplantation with 40 children who were dialyzed (27 via peritoneal dialysis and 13 via hemodialysis). We did not find any statistically significant differences in patient or graft survival between these three groups with a follow-up period of 6-87 months. Based on our results, we conclude that pre-emptive transplantation is an acceptable treatment for children who will inevitably require renal replacement therapy.

Adolescent↗
PubMed1992

Desensitization to allopurinol in patients with gout and cutaneous reactions.

PURPOSE: To determine the efficacy and safety of slow oral desensitization in the management of allopurinol-related pruritic cutaneous eruptions. PATIENTS AND METHODS: Nine patients with renal insufficiency and chronic tophaceous gouty arthritis, who had to interrupt their allopurinol therapy because of an allergic-type pruritic maculopapular eruption, were enrolled in an allopurinol oral desensitization protocol using a schedule of gradually increasing doses. RESULTS: Cautious reinstitution of allopurinol was successfully accomplished in all nine patients, but four individuals required dose adjustment because of development of a mild, recurrent, macular rash early during the protocol at allopurinol doses of less than or equal to 5 mg/d. Transient, postdesensitization cutaneous reactions occurred in two patients, one of whom also had an early rash. CONCLUSION: Oral desensitization to the minor rashes induced by allopurinol is a feasible and acceptably safe approach to therapy, particularly for those with renal insufficiency in whom no substitute urate-lowering drug is available.

Administration, Oral↗
PubMed1992

High-performance liquid chromatographic determination of biotin in biological materials after crown ether-catalyzed fluorescence derivatization with panacyl bromide.

This paper reports a high-performance liquid chromatographic (HPLC) technique to determine biotin in biological samples. Biotin and the internal standard dethiobiotin are converted into fluorescent derivatives by using panacyl bromide [p-(9-anthroyloxy)phenacyl bromide] as a fluorescence label. Biotin is extracted from biological tissue with trichloroacetic acid and the extract is purified by a combination of solid-phase extraction on C18 cartridges, ion-exchange chromatography on DOWEX formate resin, and thin-layer chromatography. The purified sample extract is derivatized in the presence of a crown ether. The resulting panacyl esters can be separated on reversed-phase as well as on normal-phase HPLC. Normal phase HPLC is preferable because it provides higher sensitivity and demands less sample pretreatment. Analysis of rat intestinal tissue revealed that only about 13% of the biotin is present in free form whereas 87% is bound in proteins from which it can be released by hydrolysis. Biotin values determined by this method are comparable to those obtained by other techniques.

Acetophenones↗
PubMed1992

Studies on the ecology of Lyme disease in a deer forest in County Galway, Ireland.

The abundance of the tick Ixodes ricinus (L.) and the infection rate of ticks with Borrelia burgdorferi (Johnson et al.) were compared on either side of a deer fence in a forest park in County Galway, Ireland, in an attempt to elucidate the role of fallow deer, Dama dama, and woodmice, Apodemus sylvaticus, in determining the population density of I. ricinus and the transmission of B. burgdorferi. The results showed that tick numbers were much higher on the deer side of the fence, although the density of mice was similar on both sides. This suggests that, in the absence of other obvious factors, deer rather than mice are responsible for tick abundance in this habitat. Tick infection rates, determined by immunofluorescence, were consistently higher outside the deer fence than inside it. It is suggested, therefore, that mice rather than deer may be the important reservoir hosts of B. burgdorferi in this habitat and that deer, by feeding many larvae, probably contribute large numbers of uninfected ticks to the population. If this is the case, there will not be a direct relationship between deer abundance and tick infection rates. This has important implications for risk assessment.

Animals↗
PubMed1992

Spinal cord arteriovenous malformation in a person with congenital lymphatic abnormalities.

Spinal cord arteriovenous malformations have been described in association with a variety of congenital diseases affecting the vasculature, including Klippel-Trenaunay-Weber syndrome, Rendu-Osler-Weber syndrome and others, but rarely in association with lymphatic abnormalities. We report the case of a young man with congenital lymphedema and arteriovenous malformations of one lower extremity and a spinal cord arteriovenous malformation. Awareness of the possible presence of a central nervous system arteriovenous malformation in individuals with pre-existing arteriovenous and lymphatic abnormalities may be helpful in their diagnosis and management.

Abnormalities, Multiple↗
PubMed1992

Tick infection rates with Borrelia: Ixodes ricinus versus Haemaphysalis concinna and Dermacentor reticulatus in two locations in eastern Germany.

Unfed nymphal Ixodes ricinus, Haemaphysalis concinna, and adult Dermacentor reticulatus were collected in two locations of Saxony in July and September 1991 by flagging. In July, the abundance of nymphal I. ricinus was about 2-3 times higher than that of nymphal H. concinna, a time of the year when nymphs of both species are reported to have a seasonal peak of activity. No D. reticulatus were flagged concurrently. In September, host-seeking activity of nymphal I. ricinus was again quite high as was that of adult D. reticulatus but only low numbers of nymphal H. concinna were collected. The flagged ticks were individually examined for Borrelia by an indirect immunofluorescence assay (I. ricinus: n = 414; H. concinna: n = 96; D. reticulatus: n = 116). The prevalence of Borrelia (probably B. burgdorferi) in I. ricinus varied from 12.1% to 21.0%. No borreliae were found in H. concinna. Of the examined D. reticulatus from one site (n = 97) 11.3% contained either B. burgdorferi or a related Borrelia. This may be the first finding of Borrelia in an Eurasian Dermacentor species.

Animals↗
PubMed1992

Covering one eye affects how some children read.

The Dunlop Test was used to identify unstable binocular control in a group of 32 mixed-ability children. They were compared with 32 reading age-matched controls. The children were then asked to read two lists of single real words of equal linguistic difficulty: one with both eyes open and the other with the left eye occluded. Only children who failed the Dunlop Test made fewer non-word errors when they read with one eye. This result provides additional support for the theory that unstable binocular control can directly affect how children read. In addition, these findings suggest that this effect must be due, at least in part, to some interaction between the images from the two eyes.

Child↗
PubMed1992

Characteristics of putrescine uptake by human brush border membrane vesicles.

Both putrescine and the polyamines spermidine and spermine are essential factors for growth and differentiation in all cells of higher eucaryotes. In principle, increased requirements of polyamines in mucosal cells either can be met by de novo-synthesis or by increasing the uptake from lumen (brush border membrane) or bloodstream (basolateral membrane). We therefore evaluated putrescine uptake in intestinal mucosal cells by using human brush border membrane vesicles (BBMV). Intravesicular uptake of putrescine was shown by osmoplots. This process was not saturable over a substrate range from 1 to 80 microM. Putrescine transport was also found to be independent of temperature (Q10 = 1.23). No differences in putrescine uptake rates were found in the presence or absence of Na+, and there was no evidence for any dependence of putrescine uptake from other cations. Our data indicate that putrescine uptake by human intestinal brush border membrane vesicles occurs by passive diffusion. It is concluded that a formerly described saturable and carrier mediated uptake in isolated intestinal mucosal cells from different species is probably influenced by active transport across the basolateral membranes. Therefore, further studies with isolated basolateral membranes are advocated.

Cell Membrane↗