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Biomedical subjects

R Hurley

Publications and source records attributed to R Hurley.

At least 37 records · Page 2Linked to original sources
PubMed1997

The role of managed care "products" in managed care "plans".

This paper presents information about the form and structure of managed care products offered by group/staff health maintenance organizations (HMOs), network/independent practice association (IPA) HMOs, and preferred provider organizations (PPOs). The information comes from a 1994 national survey of managed care plans and their arrangements with physicians. The findings confirm that multiple product offerings are now common in managed care plans. The two reasons plans most often cite for including these expanded offerings are to respond to customer interest and to ease the transition to more traditional managed care. Though plans commonly use a consistent provider network for different products, they also vary some arrangements with physicians across their products and pay them in different ways. We discuss the implications of our findings-the most comprehensive study of these issues to date-to aid in understanding the evolution of markets and of managed care, and as a basis for the design of future research and the databases it will require.

Data Collection↗
PubMed1996

Chronic proliferative hepatitis in A/JCr mice associated with persistent Helicobacter hepaticus infection: a model of helicobacter-induced carcinogenesis.

Helicobacter hepaticus causes hepatitis in selected strains of mice and in A/JCr mice is linked to liver cancer. To analyze whether H. hepaticus persists in specified ecological niches, to determine whether biomarkers of infection exist, and to analyze the influence of H. hepaticus on hepatocyte proliferation, a longitudinal study of H. hepaticus-infected A/JCr mice was undertaken. A/JCr mice were serially euthanatized from 3 through 18 months and surveyed by enzyme-linked immunosorbent assay; bacterial culture of liver, colon, and cecum; histology; electron microscopy; hepatocyte proliferation indices determined by using 5-bromo-2'-deoxyuridine; and measurement of the liver enzyme alanine aminotransferase. In infected animals throughout the 18-month study, H. hepaticus was consistently isolated from the lower bowel but only sporadically from the liver. By electron microscopy, H. hepaticus was noted infrequently and only in bile canaliculi. Infected mice, particularly males, showed chronic inflammation; oval cell, Kupffer cell, and Ito cell hyperplasia; hepatocytomegaly; and bile duct proliferation. The inflammatory and necrotizing lesion was progressive and involved the hepatic parenchyma, portal triads, and intralobular venules. Hepatic adenomas were noted only in male mice, whereas 5-bromo-2'-deoxyuridine proliferation indices were markedly increased in both sexes, but especially in males, compared to control A/J mice. Infected mice also developed sustained anti-H. hepaticus serum immunoglobulin G antibody responses and elevated alanine aminotransferase levels. H. hepaticus, which persists in the lower bowels and livers of A/JCr mice, is associated with a chronic proliferative hepatitis, and hepatomas in selected male mice indicate that this novel bacterium may cause an increased risk of hepatic cancer induction in susceptible strains of mice. This murine model should prove useful in dissecting the molecular events operable in the development of neoplasms induced by bacteria belonging to this expanding genera of pathogenic Helicobacter species.

Alanine Transaminase↗
PubMed1995

A national survey of the arrangements managed-care plans make with physicians.

BACKGROUND: Despite the growth of managed care in the United States, there is little information about the arrangements managed-care plans make with physicians. METHODS: In 1994 we surveyed by telephone 138 managed-care plans that were selected from 20 metropolitan areas nationwide. Of the 108 plans that responded, 29 were group-model or staff-model health maintenance organizations (HMOs), 50 were network or independent-practice-association (IPA) HMOs, and 29 were preferred-provider organizations (PPOs). RESULTS: Respondents from all three types of plan said they emphasized careful selection of physicians, although the group or staff HMOs tended to have more demanding requirements, such as board certification or eligibility. Sixty-one percent of the plans responded that physicians' previous patterns of costs or utilization of resources had little influence on their selection; 26 percent said these factors had a moderate influence; and 13 percent said they had a large influence. Some risk sharing with physicians was typical in the HMOs but rare in the PPOs. Fifty-six percent of the network or IPA HMOs used capitation as the predominant method of paying primary care physicians, as compared with 34 percent of the group or staff HMOs and 7 percent of the PPOs. More than half the HMOs reported adjusting payments according to utilization or cost patterns, patient complaints, and measures of the quality of care. Ninety-two percent of the network or IPA HMOs and 61 percent of the group or staff HMOs required their patients to select a primary care physician, who was responsible for most referrals to specialists. About three quarters of the HMOs and 31 percent of the PPOs reported using studies of the outcomes of medical care as part of their quality-improvement programs. CONCLUSIONS: Managed-care plans, particularly HMOs, have complex systems for selecting, paying, and monitoring their physicians. Hybrid forms are common, and the differences between group or staff HMOs and network or IPA HMOs are less extensive than is commonly assumed.

Capitation Fee↗
PubMed1995

Pyrolysis mass spectrometry of cephalosporin-resistant Enterobacter cloacae.

Thirteen clinical and four environmental isolates of third-generation cephalosporin-resistant Enterobacter cloacae (CREC) together with single isolates from the hands of a nurse and from a blood gas analyser were associated with two clusters of nosocomial infection. With an unrelated CREC isolate they had been typed by serotype, biotype, ribotype and phage-type and were examined by pyrolysis mass spectrometry (PYMS) as described here. PYMS data yielded two clusters, major and minor. All except one isolate in the major cluster corresponded to type group identity (serotype 07, biotype 62, ribotype D) which had caused neonatal sepsis and colonization. Multivariate analysis showed a homogeneous group consisting of this strain plus two outliers. The minor cluster included four different strains, one of which, serotype 03, biotype 62, ribotype C had caused excoriation of the buttocks and colonization.

Cephalosporin Resistance↗
PubMed1995

A reappraisal of chloramphenicol metabolism: detection and quantification of metabolites in the sera of children.

Seventy-four samples of serum from 27 children (age range: 26 weeks preterm to 12 y) treated with chloramphenicol for serious infections, were analyzed by high performance liquid chromatography (HPLC) for the presence of chloramphenicol metabolites. Five, including a previously unreported human metabolite--chloramphenicol aldehyde, were detected and identified by comparative HPLC, enzymic degradation or gas chromatography followed by mass spectrometry. The presence of these metabolites in the serum suggests that the biotransformation of chloramphenicol takes place by oxidation, reduction and conjugation and not by conjugation alone, as has been previously supposed. Sera from 84% of the patients contained one or more metabolites, however the presence of particular compounds did not correlate with toxicity in the four patients in whom this was observed.

Adolescent↗
PubMed1995

Maternal serum human chorionic gonadotrophin during early pregnancy resulting in boys with hypospadias or cryptorchidism.

OBJECTIVE: To compare maternal serum human chorionic gonadotrophin (hCG) samples before 18 weeks gestation in mothers of boys with cryptorchidism or hypospadias with that in mothers of normal boys. The effect of season on maternal hCG was also assessed. SUBJECTS AND METHODS: Stored serum samples from mothers of singleton male fetuses born between January 1988 and December 1992 were assayed for total hCG, using a Delfia assay. There were 153 eligible samples from 96 mothers of normal boys, 31 of those with cryptorchidism, and 26 of those with hypospadias. RESULTS: The data from mothers of normal boys were used to construct a time-specific reference range for hCG. Plotting the hCG levels of the other groups and superimposing the reference range showed no significant difference between them (P = 0.09). Maternal hCG was not significantly different between cryptorchid boys requiring orchidopexy and those experiencing early spontaneous descent. An analysis of covariance allowing for gestational age showed that maternal hCG is significantly higher during the peak summer than peak winter months (P = 0.046). CONCLUSION: While a seasonal effect on maternal hCG was demonstrated our data does not suggest this to be the sole cause for cryptorchidism or hypospadias or to account for the observation that both have a seasonal frequency.

Chorionic Gonadotropin↗
PubMed1995

Metabolism of chloramphenicol by glutathione S-transferase in human fetal and neonatal liver.

The glutathione S-transferases of human fetal and neonatal liver catalyse the conjugation of glutathione with chloramphenicol at a low but measurable rate. The highest rates were 1.30 nmol/min/mg protein in a preterm neonate of 26 weeks of gestation and 1.11 nmol/min/mg in a fetus of 22 weeks of gestation, while the lowest measurable was 0.1 nmol/min/mg in a fetus of 17 weeks of gestation. The activity did not correlate with gestational age, but appeared dependent on the concentration of glutathione in the reaction mixture. The rate rose by a factor of three, from 0.39 nmol/min/mg protein with no added glutathione to 1.24 nmol/min/mg with 2 mumol/ml added to the reaction mixture. Chloramphenicol-aldehyde was detectable in the reaction mixture when a liver extract was incubated with glutathione but the proposed intermediate, glutathione-chloramphenicol, could not be demonstrated. Differences in activity with chloramphenicol or a model substrate, under varying conditions, indicate that different isoenzymes are concerned with the conjugation of glutathione to the two substrates. These data support the hypothesis that when glucuronide conjugation is depressed by immaturity, chloramphenicol is metabolised via other pathways.

Aldehydes↗
PubMed1995

Behind the curve: a critical assessment of how little is known about arrangements between managed care plans and physicians.

Extraordinary growth in managed care arrangements over the past decade has been both widely praised and criticized. Proponents and critics agree that the nature of medical practice is being profoundly altered by this growth, even if they cannot articulate the direction and consequences of this change. We explore the roots of this uncertainty by examining the available evidence on critical features of the arrangements managed care plans currently have with affiliated physicians. Our approach is to review and synthesize the literature in several key substantive areas from a broad range of sources. We found that existing knowledge is dated, derived form a limited subset of plans, inattentive to important structural differences between plans, and responsive to a very narrow set of issues poorly reflecting the range of medical practice and change introduced by managed care. We highlight key questions of interest and the knowledge gaps critical to address so that policy and management decisions can both reflect and be informed on these issues that define the arrangements managed care plans make with physicians and ultimately influence medical practice.

Capitation Fee↗
PubMed1994

The placental transfer of cefuroxime at parturition.

Maternal and fetal serum concentrations of cefuroxime were determined at birth in 39 women who were given a single intravenous dose of either 750 mg or 1500 mg of cefuroxime before delivery. Mean serum cefuroxime concentrations in maternal venous and umbilical venous blood were dose dependent, being significantly higher after 1500 mg of cefuroxime (55.0 mg/l, 95% CI 33.4-80.9 and 19.5 mg/l, 95% CI 9.5-26.3, respectively) than after 750 mg (14.7 mg/l, 95% CI 10.5-21.1 and 8.8 mg/l 95% CI 5.8-9.4, respectively). Antibiotic concentration in maternal blood correlated with sampling time but a similar relationship was not found in cord blood. Fetal concentrations did not correlate with mode of delivery or initial maternal blood pressure. No relationship could be demonstrated between cefuroxime concentration in maternal or cord blood and maternal weight, maternal weight gain, birthweight of baby or volume of fluid infused prior to epidural anaesthesia. It is concluded that maternal and fetal concentrations likely to be effective for prophylaxis before delivery require a maternal dose of 1500 mg of cefuroxime and are independent of these physiological variables.

Analysis of Variance↗
PubMed1994

Enterobacter cloacae in a neonatal intensive care unit: account of an outbreak and its relationship to use of third generation cephalosporins.

After uneventful use of cefotaxime and ceftazidime as first line therapy for three years in our neonatal intensive care unit we isolated cephalosporin-resistant Enterobacter cloacae (CREC) strains which caused clusters of cases or colonization and/or serious neonatal infection. By using two or more typing methods, at least five different strains with similar patterns of antimicrobial sensitivities were identified. The results of a case-control study did not support the notion that the use of third generation cephalosporins was associated with colonization and infection by CREC. The outbreak was brought under control by interrupting the transmission of the epidemic strain D, by measures such as cohort nursing, diligent handwashing before and after procedures, and thorough environmental cleaning as well as by decontamination with glutaraldehyde after dismantling of the blood gas analyser believed to have acted as a persistent reservoir. Our experience highlights the danger of inadequate supervision and maintenance of equipment used for near-patient testing and the need to monitor such equipment not only in terms of its calibration and analytical performance but also microbiologically.

Blood Gas Analysis↗
PubMed1993

Treponema denticola (ex Brumpt 1925) sp. nov., nom. rev., and identification of new spirochete isolates from periodontal pockets.

Standard growth and isolation methods were used to obtain five new treponema strains in pure culture from deep periodontal pockets. The strains were identified to the species level by various methods, including agglutination, immunofluorescence, a dot blot immunoassay, electron microscopy, gas-liquid chromatography of metabolic volatile fatty acids, and DNA hybridization. Two isolates were strains of Treponema socranskii; the other three were strains of "Treponema denticola," a species described in 1925 by Brumpt. Because no type strain was designated for this species previously, the name was not included on the Approved Lists of Bacterial Names and has no current nomenclatural standing. We propose that Treponema denticola (ex Brumpt) sp. nov., nom. rev. is a valid and distinct species of the genus Treponema and designate strain ATCC 35405 as the type strain and strains ATCC 33520 and ATCC 35404 as reference strains. T. denticola appears to be the species that is most frequently isolated from periodontal pockets. Unless new isolation and cultivation techniques are introduced, it appears that present technology can yield only isolates belonging to the currently described oral anaerobic spirochete species and that there is little chance of isolating the larger treponemes.

Agglutination Tests↗
PubMed1993

Transplacental transfer of cefuroxime in uncomplicated pregnancies and those complicated by hydrops or changes in amniotic fluid volume.

The transplacental transfer of cefuroxime was determined at antenatal fetal blood sampling in a cross sectional study of 78 patients between 15-35 weeks' gestation, 8-138 minutes after a maternal intravenous dose of 750 mg. Mean serum cefuroxime concentration, measured by high performance liquid chromatography, was 7.4 (95% confidence interval (CI) 6.8 to 8.1) mg/l in control fetuses; concentrations in hydropic fetuses were similar (6.2 mg/l, CI 4.7 to 7.7) but in fetuses with oligohydramnios they were significantly lower, (4.9 mg/l, CI 3.6 to 6.2). Antibiotic concentration did not correlate with gestational age and remained unchanged by transfusion of packed red cells. We conclude that (i) fetal serum concentrations of cefuroxime obtained after a maternal dose of 750 mg are only adequate for prophylaxis against organisms with a minimum inhibitory concentration of < 4 mg/l and (ii) transplacental passage of cefuroxime is significantly reduced in the presence of oligohydramnios.

Amniotic Fluid↗
PubMed1993

Chloramphenicol toxicity.

Although high serum concentrations of chloramphenicol are related to toxicity, as shown experimentally and during treatment, the mechanism of toxicity remains unclear. Published work suggests that relatively minor metabolites may be causally related to toxic reactions in vitro and some of these metabolites have been detected in sera from treated patients. It is possible that all the major toxic manifestations of chloramphenicol may be explained by attack by free radicals. Depletion in compounds acting as cellular antioxidants, such as glutathione and vitamin E, may conceivably increase the vulnerability of an individual to chloramphenicol toxicity, while supplementation with an antioxidant might protect against it. Research into the metabolism of chloramphenicol and into the mechanism of its toxicity has declined since early work in the 1950s and 1960s, but its continuing use worldwide means that there is justification for renewed interest in the toxicology of this useful antibiotic.

Animals↗