Biomedical subjects
Publications and source records attributed to R G Rogers.
A short review of the threading approach to protein structure prediction, including presentation of some open statistical problems. Also discussed is one of the likely sources of the current limited success, that being the form of the pairwise potentials used in most threading approaches.
This paper discusses the spectrum of pregnancy-induced hypertension and presents a theory for its etiology. Endothelial injury is the purported precursor to pregnancy-induced hypertensive disorders, and this discussion expands on a possible mechanism by which injury could occur as a result of incomplete trophoblastic invasion. We review endothelin physiology and compare and contrast the evidence surrounding endothelin 1 as a putative mediator of PIH. An approach to treatment utilizing antagonists to the endothelin 1 receptor is introduced.
We reviewed hospital records of women on the obstetrics and gynecologic services with a diagnosis of antibiotic-associated diarrhea, pseudomembranous colitis, or Clostridium difficile infection to better characterize the incidence and course of women with C difficile infection. Cases were included if there was identification of C difficile by culture or toxin or endoscopic verification of pseudomembranous colitis. Between January 1985 and June 1995, there were 74,120 admissions to the obstetrics and gynecology services at two tertiary level hospitals. Eighteen women were found to have documented C difficile infection (0.02%)--3 from the obstetric services, 10 from the benign gynecologic services, and 5 from the gynecologic/oncology services. Diarrhea developed from 2 days to 30 days after antibiotics had been given (mean, 10 days). Nine patients had fever, six had nausea and vomiting, and five had abdominal pain. Antimicrobial agents given before infection included cephalexin, cefoxitin, imipenem, ciprofloxacin, trimethoprim/sulfamethoxazole, ampicillin, gentamicin, and clindamycin. All patients were treated successfully with inpatient antimicrobial agents-15 with metronidazole and 3 with vancomycin. There was one possible recurrence.
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PURPOSE: To determine whether spinal manipulation as an isolated intervention has any effect on proprioception-dependent performance of subjects with chronic neck pain, compared with effects achieved through stretching exercises. DESIGN: Matched, nonrandomized, controlled trial. SETTING: Private chiropractic clinic. PARTICIPANTS: Twenty subjects with chronic (daily, > or = 4 months) neck pain. Volunteers were recruited from a pool of patients visiting the clinic or from those referred by informed clinicians. INTERVENTION: Half of the subjects received six sessions of high-velocity, low-amplitude manipulation to the cervical and upper thoracic regions during a 3-4 wk period. The other half were instructed in stretching exercises for the cervicothoracic muscles, to be performed in two unsupervised sessions daily over the same time period. MAIN OUTCOME MEASURES: Pain levels were assessed at baseline and at each of six follow-up sessions using a 100-mm visual analogue scale. The abilities of the blindfolded subjects to reproduce a neutral head position after moving the head and neck through various planes of motion was the method used to estimate proprioceptive acuity. This was done with the use of a laser pointer affixed to the top of an adjustable cap. Points were marked and measured on a target before and after head movement and repositioning. RESULTS: Subjects receiving manipulation demonstrated a mean reduction in visual analogue scores of 44%, along with a 41% improvement in mean scores for the head repositioning skill. In comparison, a 9% mean reduction in visual analogue scores and a 12% improvement in head repositioning scores was observed for the stretching group. The difference in the outcomes of the head repositioning skill scores was significant (p < or = .05). CONCLUSION: The results suggest a possible effect of manipulation on proprioception in subjects with chronic neck pain. The small sample size, lack of true randomization and lack of blinding of the examiner are factors that weaken these findings. Larger, more controlled studies are needed to determine what specific effects manipulation may have on the function of proprioception.
Serious laparoscopic injury is rare, occurring in less than 1/1000 procedures. To our knowledge, no liver injuries have been reported to date, but avulsion of hepatic adhesions may be a source of postlaparoscopic bleeding. A woman with chronic pelvic pain unresponsive to medical management underwent an uncomplicated diagnostic laparoscopy with extensive pelvic adhesiolysis. Adhesions of Fitz-Hugh-Curtis syndrome were seen over the right lobe of the liver. At the completion of the procedure no bleeding was noted, and the patient was discharged to home in stable condition. She returned 12 hours later with a significant hemoperitoneum necessitating laparotomy. It is important to consider this as a source of bleeding after laparoscopy in a patient with perihepatic adhesions.
This study reveals how family living arrangements influence mortality. I use the National Health Interview Survey, Supplement on Aging, and discrete-time hazard rate models to show that some family arrangements result from strong social bonds, but others are a result of financial needs or health problems. In some instances, it is not family living arrangements that influence the risk of mortality but vice versa: The family rearranges itself to deal with ill health and disability among its members. The family strives to promote health, prevent disease, and encourage economic security. However, family members who endure economic or health hardships face increased risk of death.
The purpose of our study was to review the effects of Crohn's disease on pregnancy outcomes. Over a 6-year period, we identified 17 women with pregnancies complicated by Crohn's disease. The mean age of the women was 26 years, with a mean age of diagnosis at 17 years. Crohn's disease worsened only slightly during the pregnancy. Exacerbations of diarrhea were the main problems. Weight gain, unadjusted for gestational age at delivery, was 18 pounds. Three babies had low birthweight; two were both premature and growth retarded. One woman with active disease and no prenatal care had a fetal death at 30 weeks' gestation with subsequent disseminated intravascular coagulation. Among women with active perianal disease, one was delivered vaginally without exacerbation of symptoms. Four women with histories of perianal disease had prophylactic primary elective cesarean sections to avoid worsening of symptoms. Three of these women developed recurrent perianal disease despite the abdominal delivery. One of these developed an abdominal fistula trait in the wound. Our findings suggest that active disease at the onset of pregnancy tends to remain active, and quiescent disease tends to remain quiescent. Mode of delivery in our series was not protective against perineal disease. Although our series is small, it suggests that delivery may occur vaginally, with operative delivery reserved for obstetric indications.
BACKGROUND: Vulvar liposarcoma is rare. Three cases have been reported since 1966. Primary sarcomas of the vulva constitute 1-2% of all vulvar malignancies. Because of their location and appearance, they may be easily misdiagnosed as a more benign process. CASE: A 65-year-old, black woman had a vulvar lesion that appeared clinically to be a Bartholin's gland abscess. The lesion was a soft tissue mass, was excised in toto and was sent for pathologic study with a presumed diagnosis of lipoma. The pathology report indicated pleomorphic liposarcoma. CONCLUSION: Only three prior cases of this disease have been reported. The clinician should heighten his or her awareness in a patient with a vulvar mass. Early diagnosis is imperative for a favorable outcome.
OBJECTIVE: To evaluate the effect of combining carbon dioxide gas (CO2) with normal saline versus CO2 with lactated Ringer's solution on adhesion formation in the rabbit model. METHODS: Sixty New Zealand white rabbits underwent surgery based on a proven experimental adhesion model. Following abdominal closure, the animals were randomly assigned to three groups: Group 1 underwent abdominal CO2 insufflation only; group 2 underwent abdominal irrigation with CO2-saturated normal saline; group 3 underwent abdominal irrigation with CO2-saturated lactated Ringer's solution. Three weeks later, the rabbits were sacrificed and the adhesions were scored in a blinded fashion based on the extent, type, and tenacity, with a maximum possible score of 11. RESULTS: The mean (+/- standard deviation) adhesion scores were 7.75 +/- 2.82 in group 1, 7.85 +/- 2.58 in group 2, and 4.75 +/- 2.95 in group 3. There was no difference in severity of adhesions between groups 1 and 2. However, the mean adhesion score was significantly lower in group 3 (lactated Ringer's with CO2) than in either group 1 (CO2) or group 2 (normal saline with CO2) (P = .004 and P = .002, respectively). CONCLUSION: It appears that when CO2 is the insufflating gas, lactated Ringer's solution has a protective effect against adhesion formation in the rabbit model.
This paper examines the demographic and social factors associated with differences in length of life by race. The results demonstrate that sociodemographic factors--age, sex, marital status, family size, and income--profoundly affect black and white mortality. Indeed, the racial gap in overall mortality could close completely with increased standards of living and improved lifestyles. Moreover, examining cause-specific mortality while adjusting for social factors shows that compared to whites, blacks have a lower mortality risk from respiratory diseases, accidents, and suicide; the same risk from circulatory diseases and cancer; and higher risks from infectious diseases, homicide, and diabetes. These results underscore the importance of examining social characteristics to understand more clearly the race differences in overall and cause-specific mortality.
This research employs the National Health Interview and the National Mortality Followback Surveys to calculate life expectancies by age and sex for white nonsmokers, former smokers, and current smokers in the United States in 1986. In general, life expectancies are higher for never smokers than for former smokers, and higher for former smokers than for current smokers. Heavy smokers have lower life expectancies than persons with all other smoking statuses; indeed, compared to never smokers, heavy smokers at age 25 can expect at least a 25% shorter life. Gender differences in life expectancies were found to persist even with the elimination of smoking. Differences in life expectancy by sex thus appear to be due, in part, to cigarette smoking, but also to occupational, environmental, and sociodemographic factors.
Evidence suggests that among mainland-born decedents. Hispanic (particularly Puerto Rican) origin may have been underreported in states that have added an ancestry item to their death certificates. This study uses the 1980 Census Bureau Spanish-surname list to code surnames on New York City death certificates. By examining the correspondence between surname type and the response to the ancestry item, we identify potential underreporting of Hispanic ethnicity for Spanish-surnamed decedents. A surname-based method then is used to adjust mortality data for mainland-born Puerto Rican decedents.
A number of recent cross-sectional studies of longevity and health among the elderly have concluded that recent positive trends in the prolongation of life have not been matched by similar trends in the extension of healthy life. This paper challenges that pessimistic conclusion by examining conceptual issues related to the measurement and dynamics of the mortality-disability process. It uses data from the 1986 Longitudinal Study of Aging (U.S. Department of Health and Human Services, 1988) to illustrate its principal points.
Various studies have enquired into the influence of socioeconomic development or public health measures on life expectancies in less developed countries. Analysis of the effect of these two groups of factors upon life expectancy, using data for 95 less developed countries, indicates that mortality is primarily influenced by such socioeconomic development measures as urbanization, industrialization, and education, and secondarily by such public health measures as access to safe water, physicians, and adequate nutrition.
Calculations of multistate life expectancy not only measure how long a population may live beyond a certain age, but also what fractions of this continuing lifetime will be spent in an independent or dependent status. Many Americans aged 70 and over are leading long, active lives; large numbers of individuals who become dependent, moreover, do so temporarily and return to independent status. Men and women have disparate total and active life expectancies, however, reflecting differential survival patterns and varying rates of transition among statuses. Policy makers must consider the increased size of the future elderly population, and changes in its age composition and functional status, when planning relevant health services.
This article examines ethnic differences in cause-specific infant mortality, using linked birth and infant death records from a cohort of New Mexican singleton infants, 1980-1983. The research, which applies log-linear analysis, focuses on the combined influences of ethnicity, birth weight, maternal age, and plurality on birth outcomes--that is, on infant survival and deaths due to perinatal, congenital, and respiratory diseases and to sudden infant death syndrome. The results confirm the pronounced impact of birth weight on infant mortality and identify similarities and differences among Anglo, Hispanic, and American Indian babies with respect to cause-specific infant mortality.
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