Discovery of a 2'-fluoro-2'-C-methyl C-nucleotide HCV polymerase inhibitor and a phosphoramidate prodrug with favorable properties

A series of 2'-fluorinated C-nucleosides were prepared and tested for anti-HCV activity. Among them, the triphosphate of 2'-fluoro-2'-C-methyl adenosine C-nucleoside (15) was a potent and selective inhibitor of the NS5B polymerase and maintained activity against the S282T resistance mutant. A number of phosphoramidate prodrugs were then prepared and evaluated leading to the identification of the 1-aminocyclobutane-1-carboxylic acid isopropyl ester variant (53) with favorable pharmacokinetic properties including efficient liver delivery in animals.

Relationship between conditional early acceptance into medical school and medical school leadership and academic performance: the Conley Scholar experience at the University of Missouri-Columbia

The Conley Scholars Program at the University of Missouri-Columbia was created in 1987 to guarantee top flight students entrance to medical school without the frantic competition well known in undergraduate pre-med programs. The program provides greater freedom as undergraduates than most combined baccalaureate-MD programs. It is not known how this freedom and avoidance of the "pre-med syndrome" affects medical school performance and relative leadership qualities compared to traditional medical students. The goals of this study are to: a) compare relative composition and performance of Conley medical students to traditional medical students; b) assess the role of Conleys in leadership positions within medical school organizations.

METHODS

Using the medical school computer data files and AMCAS application files, composition, academic, and leadership data were collected regarding all medical school classes containing Conleys. Statistical analysis was performed on all data.

RESULTS

The results suggest that: a) Conley Scholars averaged significantly higher undergraduate GPAs than other medical students; b) Conley Scholars averaged higher GPAs throughout medical school; c) Conley Scholars are more likely to hold medical school leadership roles than traditional medical students.

CONCLUSIONS

The results confirm the value of the Conley Scholar Program. Benefits extend beyond academic achievement to encompass the development of leadership skills recognized by faculty and peers.

Quality of the family physician component of AMA Masterfile

BACKGROUND

This investigation was undertaken to gain insight into the validity of the American Medical Association (AMA) Masterfile data.

METHODS

Allopathic family physicians were chosen as the study population Omissions were picked up from by comparing the AMA list with the 1990 Ohio Academy of Family Physicians Foundation-Ohio Department of Health (OAFPF-ODH) census. Verification of the 1990 specialty and geographic location of allopathic family physicians not common to both files was achieved by sequentially (1) reviewing the AMA names against 1990 deletions from the 1985 OAFPF-ODH census, (2) contacting physicians directly by telephone, (3) verifying 1990 physician status with county medical personnel, and (4) mailing a brief questionnaire to each physician whose 1990 status remained unverified.

RESULTS

The status of specialty and geographic location in 1990 was verified in 91 percent of names not common to both lists. Incorrect omissions (undercounts) and incorrect inclusions (overcounts) offset each other for both lists. Two groups of family physicians contribute to counting biases: family physicians who fulfill short-term goals by part-time practice in several locations, and family physicians who restrict their practice to a limited medical content area.

CONCLUSIONS

Because of nearly equal offsetting of overcounting (incorrect inclusions) and under counting (incorrect omissions), the 1990 Ohio family physician AMA Masterfile data is adequate for work-force projections and policy studies when the county data are aggregated at the state level. The overcounting and undercounting for smaller areas or categories must still be studied, however. Application of the AMA Masterfile data of other geographic areas requires a knowledge of the components of undercounts and overcounts of the population being studied.

Generalist physicians in nonmetropolitan countries in Ohio

OBJECTIVE

To identify by specialty (family practice, general internal medicine, and general pediatrics) the number and ratios of generalist physicians per 100,000 population in nonmetropolitan counties in Ohio and to describe the trends in these data from 1975 through 1990.

DESIGN

The data were compiled on a country basis by physician census takers residing in each county in Ohio. The US Office of Management and Budget's definition of nonmetropolitan counties formed the basis of the calculations.

RESULTS

In nonmetropolitan counties of Ohio, generalist physician numbers and ratios improved between 1975 and 1990 in general internal medicine (from 5.9 to 10.2 per 100,000 population) and general pediatrics (from 2.6 to 4.9 per 100,000 population) but not in family practice, which experienced a decrease from 31.0 to 28.7 per 100,000 population. Eight counties with no hospitals were unable to attract general internists or general pediatricians.

CONCLUSIONS

The results of this study indicate the importance of characterizing generalist physician workforce data by specialty and practice location on a state-wide basis and suggest that increasing the supply of physicians does not greatly improve the geographic distribution of the medical workforce. These findings should affect the development of local, state, and federal physician workforce policies aimed at addressing the problem of physician geographic maldistribution.

Occurrence of Clostridium tetani in soil and horses

The annual incidence of tetanus in the RSA is up to 300 cases with more than 50% of these coming from Natal/KwaZulu. The condition of playing fields and the excretion of Clostridium tetani by horses was therefore investigated. The overall contamination rate of soils in the Durban area is lower than that of published data from other parts of the world, for instance 28% for Durban in comparison with 31-42% for Japan and Quebec. A rugby field in the Transvaal showed 40% contamination and a pasture used for horses for more than 20 years 65%. No case of human or equine tetanus has ever been reported from either the playing field or the pasture. A permanent carrier state in horses could not be established; the organisms were only excreted for 3-4 days. At any one time only 2 out of 27 horses in a stable were excreting C. tetani. Only 7 of 118 faeces samples were positive over a period of 4 months (5-9%).

Tetracycline and amphotericin B vaginal cream for mixed vaginal infections

A tetracycline and amphotericin B vaginal cream (Vagmycin; Squibb) was highly effective in mixed vaginal infections. More than 95% of patients had symptomatic relief while 85% showed bacterial and clinical response. There appeared to be little difference whether the cream was applied for 1 week or 2 weeks. A group of asymptomatic patients were evaluated to compare alterations in normal and pathological organisms as a result of treatment.

Oxygen dependence of human alveolar macrophage-mediated antibody-dependent cytotoxicity

We studied the metabolic characteristics of the human alveolar macrophage-mediated antibody-dependent cytotoxicity (ADCC) reaction, using an anti-D sensitized human erythrocyte target system. Metabolic experiments demonstrated a high resting rate of glucose metabolism in macrophages, but no oxidative metabolic burst was found to accompany the ADCC reaction. These findings were confirmed by oxygen consumption studies, showing a high resting rate of oxygen consumption by macrophages, but no change in the rate of oxygen consumption upon the addition of antibody-sensitized target cells. An anaerobic mechanism for ADCC was anticipated and investigated. Surprisingly, the macrophage-mediated ADCC reaction was found to be highly oxygen dependent. The macrophages of one chronic granulomatous disease patient were also studied and found to have a very low rate of oxidative metabolism in response to phagocytic stimuli. With oxygen present, these macrophages failed to produce significant ADCC, suggesting again that some oxidative mechanism was necessary in the macrophage-mediated ADCC reaction. Various oxygen radical scavengers were also studied. Glutathione inhibited ADCC significantly, and benzoic acid inhibited ADCC only slightly. All other scavengers had no significant inhibitory effect. Then, a known antioxidant and inhibitor of mixed-function oxidases, diethyldithiocarbamate, was found to produce a significant inhibition of the ADCC reaction. We believe this compound may be scavenging or inhibiting the production of some oxygen-dependent species important in the ADCC reaction.

Vascular anatomy of the human uterus and pregnancy wastage

In uteri removed at hysterectomy the uterine arteries were injected with radioopaque media and the vascular configuration was correlated with reproductive histories. Patients whose uteri had two ascending uterine arteries on each side had significantly more abortions and smaller newborn infants than patients with a single ascending branch of the uterine artery.

Matuhasi-Ogata phenomenon involving anti-ampicillin

A 47-year-old group A, Rh1Rh1 woman treated with intravenous ampicillin for chronic pyelonephritis received two units of blood and also received oral cephalexin. Three months after the transfusions she was noted to have allo-anti-E and anti-c, and a 2+ positive direct antiglobulin test. Anti-E and anti-c could be eluted from her cells, yet neither antigen could be demonstrated on the patient's circulating red blood cells. Also present in the serum and in the eluate was anti-ampicillin antibody. Studies of the patient's red blood cell eluates using ampicillin-treated R1R1 and untreated R2R2 cells demonstrated anti-E complexed with anti-ampicillin in a drug-related example of the Matuhasi-Ogata phenomenon. Artificially created mixtures of anti-E and drug antibody could reproduce the effect in vitro. No effect of cephalexin could be demonstrated. The variability of the Matuhasi-Ogata phenomenon is discussed with regard to the sequence of antibody attachment, and the possible relationship to cephalexin is discussed. Drug antibodies may be involved in the Matuhasi-Ogata phenomenon in cases where another red blood cell antibody cannot be shown to be present.