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Biomedical subjects

R L Cook

Publications and source records attributed to R L Cook.

At least 19 recordsLinked to original sources
PubMed1992

Factors associated with pediatricians' participation in Medicaid in North Carolina.

OBJECTIVE: To describe the relative importance of factors influencing pediatricians' participation in Medicaid in North Carolina. DESIGN: Questionnaire survey. SETTING AND PARTICIPANTS: Nonacademic primary care pediatricians in direct patient care at least 50% of the time; 332 (85%) of the 389 eligible pediatricians responded. MAIN OUTCOME MEASURES: Proportion of pediatricians who restricted Medicaid patients' access to their practices. The association between restricting access and the following factors was assessed: Medicaid reimbursement, pediatricians' demographic characteristics, knowledge of the Medicaid program, attitudes toward Medicaid patients and the Medicaid program, and beliefs about whether other physicians were available to care for Medicaid patients. RESULTS: Twenty-nine percent of pediatricians restricted Medicaid patients' access to their practices. The proportion of pediatricians restricting access was 62% in cities, 13% in medium-sized towns, and 12% in small towns (P less than .001), but the proportion of pediatricians in cities who restricted access varied from 87% to 22%. Pediatricians who received a higher proportion of their usual fee were less likely to restrict Medicaid patients' access. The relationship between Medicaid payment and restricted access was substantially weakened after controlling for the following factors: (1) the size of the community, (2) pediatricians' attitudes toward Medicaid payment, (3) their perceptions that they were too busy to care for Medicaid patients, and (4) whether there were other resources for the care of Medicaid patients. At comparable levels of payment, rural pediatricians were about six times less likely than urban pediatricians to restrict access. Pediatricians who knew less about Medicaid reimbursement also restricted access more often. Whether or not they restricted access to new Medicaid patients, pediatricians provided acute, preventive, hospital, and emergency care to the Medicaid patients who were already in their practices. CONCLUSIONS: Existing resources for the care of Medicaid patients, pediatricians' economic dependence on Medicaid, and the local norms of practice may be important factors in pediatricians' decision to participate in Medicaid. Increasing reimbursement will have only modest effects on Medicaid participation. Strategies to improve participation should also address pediatricians' knowledge of the Medicaid program and enlist the support of community physicians.

Attitude of Health Personnel↗
PubMed1992

Time allocation of students in basic clinical clerkships in a traditional curriculum.

The objective of this study was to determine the amounts of time spent in various activities by medical students enrolled in basic clinical clerkships. In the fall of 1989, 80 third-year students at the University of North Carolina at Chapel Hill School of Medicine recorded their time allocations in eight categories over 24 hours for three consecutive days. After personal time, the students spent the greatest amount of time in organized educational activities (rounds, conferences, lectures), followed in decreasing order by chartwork, patient contact, examination study, ancillary activities, procedures, and directed study. The students reported an average of 5.8 hours of sleep per night. The students reported that when they were on call, they had significant increases in patient contact, chartwork, and ancillary activities. The authors suggest that third-year students may spend too much of their time in organized educational activities, and may benefit educationally from increased amounts of patient contact and decreased amounts of ancillary activities. These data provide an opportunity for clerkship and curriculum organizers to analyze the efficacy of the basic clinical clerkships.

Adult↗
PubMed1992

Clinical, microbiological, and biochemical factors in recurrent bacterial vaginosis.

Because so little is known about the pathogenesis of recurrent bacterial vaginosis (BV), a longitudinal microbiological study was conducted on 13 women with recurrent BV treated sequentially with conventional metronidazole therapy. A rapid clinical response characterized by disappearance of mal odor and an improvement in vaginal discharge occurred in 92% of 31 clinical episodes of BV, with patients no longer satisfying the composite clinical criteria for the diagnosis of BV. However, prospective evaluation of these asymptomatic women revealed profound residual biochemical and microbial abnormalities which were best evident on Gram stain and wet mount examination of vaginal secretions. Other common residual abnormalities included mild persistent elevation of vaginal pH and polyamine and fatty acid levels and the presence of clue cells in small numbers. Residual abnormalities could be quantified to create an overall symptom code which predicted recurrence, and it was found that the severity of residual abnormalities was inversely related to the time required until the next recurrence occurred. The severity and prevalence of residual abnormalities following clinically successful therapy support the concept that BV recurrence, especially when it is early, represents a relapse rather than a reinfection. This concept may have important therapeutic implications.

Adult↗
PubMed1991

Therapeutic interchange of ampicillin-sulbactam for cefoxitin.

A therapeutic interchange program based on microbial patterns within an institution is described. A change in anaerobic susceptibility patterns, increased prevalence of enterococcal infections, and cost factors provided the rationale for the therapeutic interchange of ampicillin-sulbactam for cefoxitin. Ampicillin-sulbactam was recommended for prophylaxis in intraabdominal or gynecological surgery as well as for treatment for gynecological infections. Cefoxitin was restricted to penicillin-allergic patients and women who were pregnant or breast-feeding. The transition from cefoxitin to ampicillin-sulbactam proceeded smoothly as a result of preliminary education of pharmacists and physicians. Pharmacists participated in continuing-education programs and received concise guidelines for the interchange and follow-up instructions; physicians learned of the program from the drug newsletter published by the pharmacy department. Three months after the program began, only one physician was resistant to the interchange. After the program began, 11 antimicrobials, including cefoxitin, were used less frequently and ampicillin-sulbactam use increased. No adverse clinical consequences from the interchange were detected. A therapeutic interchange program based on institution-specific microbial patterns and educational efforts by the pharmacy department produced a change in physician prescribing.

Ampicillin↗
PubMed1991

In vivo effects of putative crowding factors on development of Hymenolepis diminuta.

During in vitro incubation, Hymenolepsis diminuta secretes substances into the medium that inhibit DNA synthesis in the germinative region of freshly isolated, uncrowded worms. Of the many substances that are released by H. diminuta into the medium, earlier studies indicate that only succinate, acetate, glucosaminic acid, and cGMP are responsible for the inhibition. In the present report, effects of these putative crowding factors on worm development in vivo were examined. At 7 days postinfection the proximal end of the host's intestine was catheterized and perfused with test solution. The test solution contained 28 nM cGMP, 250 microM glucosaminic acid, 120 mM succinate, and 40 mM acetate. The solution was perfused by a peristaltic pump at a rate of 50 ml/day. At 2 wk postinfection, worms were recovered for subsequent analysis. Worms developing in the presence of crowding factors were 53% less in wet weight than control worms. Carbohydrate concentrations in worms from experimental groups were not different from those in control groups; therefore, the inhibition in growth was probably not due to carbohydrate deprivation. Worms from experimental groups had fewer immature, mature, and gravid proglottids than did worms from control groups. The results are consistent with the hypothesis that the tested substances, which inhibit DNA synthesis in H. diminuta in vitro, are a part of the cause of the crowding effect in vivo.

Acetates↗
PubMed1991

Immune thrombocytopenic purpura in pregnancy: a reappraisal of management.

Management and, particularly, mode of delivery of the pregnant patient with immune thrombocytopenic purpura (ITP) are controversial. We reviewed our experience with 31 pregnancies in 25 women with ITP over a 10-year period. Fourteen infants were born vaginally and 18 by cesarean. Six major complications occurred among mothers delivered by cesarean, whereas none occurred among those born vaginally (P = .028). Three of 32 infants were born with moderate thrombocytopenia (platelet count 51-100 x 10(9)/L) and two with severe thrombocytopenia (platelet count 50 x 10(9)/L or less); there were no clinically significant complications in these infants. No maternal characteristic could be used to predict the neonatal platelet count. In an analysis of 474 infants of mothers with ITP reported in the literature and including the present series, 10% were born with moderate thrombocytopenia and 15% with severe thrombocytopenia. The overall rate of intracranial hemorrhage in newborns with moderate or severe thrombocytopenia was 3%. No significant association was found between the rate of intracranial hemorrhage and delivery mode for moderately and severely thrombocytopenic neonates together (weighted odds ratio 1.69, 95% confidence interval 0.14-44.6) or for those with severe thrombocytopenia (crude odds ratio 1.38, 95% confidence interval 0.07-84.67). We conclude that the mode of delivery may not affect the rate of intracranial hemorrhage in thrombocytopenic newborns.

Delivery, Obstetric↗
PubMed1990

Effect on urogenital flora of antibiotic therapy for urinary tract infection.

Specimens were examined from 70 female presenting with urinary tract infection. 50 patients were randomly treated with 7 days amoxicillin or bacampicillin and another 20 randomly received amoxicillin or enoxacin. Effective clearance of the infections was achieved with each antibiotic, and only minor side effects occurred. Bacteriological analyses of the urogenital flora demonstrated a relationship between urethral carriage and bladder infection, with Escherichia coli being the most common pathogen. Antibiotic resistant E. coli were isolated more frequently from the bladder, urethra, introitus and rectum following amoxicillin treatment compared to bacampicillin and enoxacin. An examination of the urogenital flora post therapy showed that an indigenous lactobacillus population had not been restored in the majority of patients. Rather, uropathogenic bacteria were found to dominate the urethra and introitus. The effects of antibiotics on urogenital flora is clearly a matter of importance. Future clinical trials should address this. It may be that artificial supplementation of indigenous bacteria is necessary to restore the flora back to normality.

Adolescent↗
PubMed1989

Clue cells in bacterial vaginosis: immunofluorescent identification of the adherent gram-negative bacteria as Gardnerella vaginalis.

Clue cells are epithelial cells covered by adherent gram-negative rods, observed in vaginal smears from women with bacterial vaginosis. Immunofluorescence studies were used to identify the gram-negative bacteria adhering to clue cells. Specific antisera to four common gram-negative vaginal bacteria (Gardnerella, Bacteroides, Fusobacterium, and Mobiluncus) were prepared by long-term, multiple, small-inoculum immunization of rabbits. Cross-reactivity with heterologous common vaginal bacteria was removed by absorption against whole cells of heterologous bacteria and by serial dilution. Gardnerella vaginalis was most often observed adhering to the surface of clue cells and was detected on the surface of exfoliated vaginal epithelial cells significantly more frequently and in higher numbers than were Mobiluncus, Bacteroides, and Fusobacterium, suggesting that this species of gram-negative bacteria is responsible for clue cell formation.

Bacteroides↗
PubMed1988

Lactobacillus inhibitor production against Escherichia coli and coaggregation ability with uropathogens.

Previous investigations have shown that certain strains of lactobacilli can competitively exclude uropathogens from attaching to uroepithelial cells and from causing urinary tract infection in animals. The finding of an inhibitory effect produced by Lactobacillus casei ssp. rhamnosus GR-1 against the growth of uropathogens was investigated further using two Escherichia coli indicator strains Hu 734 and ATCC 25922. There were two phases to the inhibitor studies. The first one using an agar sandwich technique showed that the inhibitor activity was heat stable and inhibitory to the E. coli. The second phase showed that MRS broth provided optimum lactobacilli growth and inhibitor production. In addition, the inhibition was present under conditions buffering for acid and pH. The data indicated that the inhibitory effect was not due to bacteriophages or hydrogen peroxide. Strain GR-1 was found to coaggregate with E. coli ATCC 25922 in urine, a phenomenon that has not previously been reported for urogenital bacteria. An in vitro assay system was developed to study the coaggregation of various lactobacilli and uropathogens. The results demonstrated that highest coaggregation scores occurred after 4 h incubation at 37 degrees C with lactobacilli and two type-1 fimbriated E. coli strains. Of the nine lactobacilli strains tested, each was found to coaggregate with 2 or more of the 13 uropathogens. The dominance of inhibitor-producing lactobacilli on the urogenital epithelium and the ability of these organisms to interact closely with uropathogens would constitute an important host defense mechanism against infection.

Bacterial Adhesion↗
PubMed1987

Examination of strains of lactobacilli for properties that may influence bacterial interference in the urinary tract.

Lactobacilli strains vary in their ability to interfere with colonization of uroepithelial cells by pathogenic organisms. Bacterial size, adherence capability, competitive exclusion and inhibition of pathogenic growth were examined in selected strains of lactobacilli to assess their relative importance. We tested adherence to uroepithelial cells of 34 lactobacillus isolates originating from the urogenital tract, dairy sources and chickens, and 1 lactobacillus strain isolated from a commercially available preparation. The ability to adhere differed greatly among the 34 strains, with a range of 8 to 74 bacteria per cell, and the commercial strain attached poorly with a mean of 15 bacteria per cell. Eleven strains of lactobacilli were selected and found to differ in length and width dimensions. These strains were found to exclude competitively with varying efficiency 6 strains of uropathogens from adhering to uroepithelial cells. The effective ability of Lactobacillus casei GR-1 to exclude the uropathogens confirmed previous findings and other strains (GR-2, GR-3 and A-60) gave a similar range of exclusion. The lactobacillus isolates varied greatly in their ability to inhibit the growth of 11 uropathogens under the conditions of an agar overlay inhibition assay. A combination score was allocated to each of the 11 lactobacillus strains based on size, adherence, exclusion and inhibition. Lactobacillus casei GR-1 attained the highest score while the commercial strain attained the lowest score. The results of this study identified 4 properties that should be examined to select lactobacillus strains before embarking upon bacterial interference studies to prevent urinary tract and other infections in humans.

Animals↗
PubMed1987

Analysis of changes in rat prostate carcinoma following hormone deprivation.

The R3327-H model of prostatic adenocarcinoma was employed for the study of the cellular changes that occur during induction, regression, and recurrence of prostate cancer after endocrine therapy. The present study was designed to compare the glandular and stromal elements of the relapse phase with the histologically distinct early and intermediate phases of tumor progression. Morphometric analysis revealed significant differences between all three groups in the percentages of total tumor occupied by the epithelial component. At all three time periods, high-power inspection of autoradiograms prepared after incubation of the tissues with radioactive dihydrotestosterone revealed large cells in the stroma, especially in the intermediate phase. Immunohistochemistry further revealed evidence of invasion across the prostatic acinar basement membranes by similar cells. These studies lead the authors to postulate a mechanism by which hormone-independent cells in the epithelium repopulate the stroma, causing a recapitulation of the original morphology of the tumor in the postremission period. They propose that prostate tumor response to estrogen therapy can be operationally defined in three phases: involution, rebound, and relapse. They infer that further knowledge of the timing of these phases may permit early selective use of specific therapeutic strategies which will be able to balance the clinical risk with the known behavior of the neoplasm during progression of the disease.

Adenocarcinoma↗
PubMed1985

Melphalan: a potential new agent in the treatment of childhood rhabdomyosarcoma.

Melphalan has been evaluated against a series of seven childhood rhabdomyosarcomas, each derived from a different patient and maintained in vivo as xenografts in immune-deprived mice. Six lines were derived from untreated tumors and one from a patient refractory to conventional therapy. At the maximum tolerated dose (LD10) a single administration of melphalan caused complete regressions of advanced tumor in six of seven lines, including xenografts derived from the refractory patient. This agent demonstrated activity over a broad range of doses, and was considerably more active than vincristine, cyclophosphamide, doxorubicin, and dactinomycin in the model.

Animals↗
PubMed1984

Childhood rhabdomyosarcoma xenografts: responses to DNA-interacting agents and agents used in current clinical therapy.

A laboratory model of childhood rhabdomyosarcoma (RMS) has been used to evaluate cytotoxic agents used in current clinical protocols, and DNA-reacting agents that have had either limited or no evaluation in this histiotype. Seven lines of RMS each derived from a different patient were grown as xenografts in immune-deprived mice, six of these being from specimens derived from previously untreated patients. Of the 'conventional' agents, vincristine was the most effective. Of the other agents evaluated [L-phenylalanine mustard (L-PAM), cis-dichlorodiammineplatinum (cis-DDP), mitomycin C and 5-(3,3-dimethyl-1-triazeno)-imidazole-4-carboxamide (DTIC)], L-PAM caused complete regressions in six of seven lines, including those resistant to cyclophosphamide. DTIC had marked activity in five tumors, and mitomycin C in three lines. Cyclophosphamide was active in five tumors, although efficacy was less marked in two lines in comparison to DTIC and mitomycin C.

Animals↗
PubMed1984

Small hospital support of unscheduled overnight air evacuation.

On January 13, 1982, the entire east coast of the United States experienced a severe snowstorm. Blizzard conditions caused closure of civilian airports and Air Force runways. In the midst of the storm, an MAC C-141 aircraft with 48 people on board was inbound from Germany. Diminishing fuel and crew rest requirements made the situation urgent. Loring AFB, ME, had an open runway; and a small 20-bed hospital which accepted the challenge of providing remain-overnight (RON) facilities for the 34 patients and 7 nonmedical attendants from the flight. Within 2 h of arrival, the people from the flight had been fed, were settling for the night, had their records reviewed, were visited by medical staff, and had trebled the inpatient population of the hospital.

Aerospace Medicine↗
PubMed1981

Nursing peer review: a survey of flight nurse section members.

Thirty Flight Nurse Section attendees at the 1980 AsMA meeting participated in a survey regarding nursing peer review. Respondents were middle-to-senior level nurses with a mean age of 39.8 +/- 8.13 years, and mean military grade of Major. While not representative of a broad spectrum of nurses, the responses have great value. Demographic and peer review data are presented, followed by a discussion of findings and recommendations.

Adult↗