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Biomedical subjects

D Fraser

Publications and source records attributed to D Fraser.

At least 109 records · Page 6Linked to original sources
PubMed1994

Epidemiology of Shigella infections in two ethnic groups in a geographic region in southern Israel.

The epidemiology of shigellosis in the Jewish and Bedouin populations that coexist in the same geographic region in southern Israel and share the same medical facilities but live separately under different socioeconomic conditions was examined in a retrospective, culture-based study. The average annual attack rate for the four-year period 1989-1992 was 368/100,000 inhabitants. The average annual attack rate among the Jews, who enjoy Western socioeconomic conditions, was 413/100,000 and the disease showed summer and winter peaks. Shigella sonnei caused 3,336 of 4,560 (73.2%) attacks in this group, and the attack rate of Shigella flexneri decreased during the study period. Among the Bedouins, many of whom live in poverty and overcrowding, a single annual summer peak was observed, the average annual attack rate being 197/100,000 and Shigella flexneri caused 389 of 583 episodes (66.7%). Resistance to ampicillin or tetracycline was noted in 57% of all Shigella isolates, and 82% were resistant to cotrimoxazole. It is concluded that shigellosis is highly endemic in southern Israel, resistance to antimicrobial drugs is common and living conditions of the population influence the seasonal occurrence of the disease and select for morbidity with specific organisms.

Anti-Bacterial Agents↗
PubMed1994

Acquisition of immunity in mothers of infants administered trivalent oral poliovirus vaccine.

The hypothesis that live oral poliovirus vaccine (OPV) confers immunity to persons in close contact with the vaccine recipient was tested by comparing cord blood antibody titers in 31 first-born neonates to those of 48 neonates with one or more siblings adequately immunized with OPV. A borderline or negative result (defined as a reciprocal titer of < or = 8) for at least one type was significantly more prevalent among first-born neonates than among neonates with one or more siblings [17/31 (55%) versus 17/48 (27%) respectively; p < 0.03]. This difference was consistent for all three poliovirus types. The geometric mean titer (GMT) was consistently higher for each serotype in infants with one or more siblings compared with first-born neonates: 134.9 versus 64.5 for poliovirus 1; 262.1 versus 95.6 for poliovirus 2; and 48.6 versus 19.4 for poliovirus 3, respectively. When cord blood of neonates with two or more siblings was compared to that of neonates with only one sibling, no difference in titers was observed. Since mothers of one or more infants were on average older and less educated, the results were adjusted accordingly, but the same trend was observed again. These findings support the notion that OPV is important, not only as a vaccine for the individual infants, but also as a means of conferring immunity to persons in close contact.

Adult↗
PubMed1994

Detection of Cryptosporidium and Giardia intestinalis in Bedouin children from southern Israel.

During an 18 month period, a total of 4796 stool specimens collected from 151 Bedouin children enrolled in a cohort study and followed from birth, were screened for Giardia intestinalis, Cryptosporidium spp. and other intestinal parasites. Specimens were collected in phenol-alcohol-formalin (PAF) preservative and examined prior to, and after, formalin-ether concentration (FEC). During 6 months of the second year Giardia intestinalis was observed in 17.6% of the specimens and Cryptosporidium in 0.9% as compared with 1.8% (Giardia intestinalis) and 1.6% (Cryptosporidium) observed during the first year. Giardia intestinalis was detected in 8.4% (407/4796) of all the samples examined and Cryptosporidium in 1.3% (63/4796). Other intestinal protozoan parasites and helminthic ova demonstrated in the stool specimens included: Entamoeba coli (0.1%); Entamoeba histolytica (< 0.1%); Hymenolepis nana (0.1%); and Trichuris trichiura (< 0.1%). Mixed infection with 2 parasites was observed in 0.3% of the specimens. PAF fixation was found to be highly effective in preserving the integrity and antigenicity of both Cryptosporidium-oocysts and Giardia intestinalis-cysts. The detection rate of Giardia intestinalis and Cryptosporidium before FEC was not significantly different from that obtained after FEC, showing differences of only 1% and 3% for Giardia intestinalis and Cryptosporidium, respectively.

Animals↗
PubMed1994

Birth weight discordance, intrauterine growth retardation and perinatal outcomes in twins.

In a population-based study, the association between twin perinatal outcome, birth weight discordance and intrauterine growth retardation (IUGR) was investigated. Mortality was examined in 1,145 twin pairs, and neonatal morbidity was studied in 315 live-born pairs. In this study, birth weight discordance was defined as > or = 25% of the weight of the heavier twin, and IUGR was defined as < 10th percentile of gender- and gestational age-specific singleton birth weight. In univariate analyses IUGR and discordance were associated with mortality but not with morbidity. When twins were categorized by discordance and IUGR simultaneously, stillbirths were associated with IUGR, while discordant twins had elevated risks of early neonatal death. In multiple logistic regression analyses, which also included gestational age, mode of delivery, birth order, birth weight discordance and IUGR, low birth weight was the single consistent factor associated with elevated risks of mortality and morbidity. For every 250-g increase in birth weight, the risks for each condition examined fell by about 40%. Discordance was an independent risk factor only for hypoglycemia, while IUGR was not associated with any neonatal outcome. Birth weight itself seems to be the most important factor associated with perinatal outcome in twin births. Therefore, the weight of the individual fetus should be the focus of concern of the medical profession in the effort to reduce adverse outcomes in twin pregnancies.

Analysis of Variance↗
PubMed1993

Reverse transcriptase families and a copia-like retrotransposon, Osser, in the green alga Volvox carteri.

By using the polymerase chain reaction (PCR) we have isolated and sequenced two distinct families of reverse transcriptase (RT) sequences from the genome of the colonial alga, Volvox carteri. Probing a genomic library with these RT clones revealed copia-like retrotransposons. One of these elements, named Osser, is 4,875 bp long, bordered by 197-bp identical long terminal repeats (LTRs), and shows the typical organization of retrotransposons belonging to the copia-Tyl group. This is the first complete copia-like retrotransposon sequence described in a green alga.

Amino Acid Sequence↗
PubMed1993

Maternal mortality in southern Israel.

Between 1969 and 1991 there were 166,410 births in Southern Israel with 13 maternal deaths (7.8/100,000). In the Jewish population there were 119,130 deliveries with 7 maternal deaths (5.9/100,000), and the Bedouins had 47,280 deliveries with 6 maternal deaths (12.7/100,000). Prenatal care was an important preventive factor. 7 maternal deaths occurred among 151,088 women who had received prenatal care (4.6/100,000), whereas 6 such deaths occurred among 15,322 without prenatal care (39.1/100,000) (P value 0.0005). Ten of the 13 women who died were over 24 years old. Eight of the 13 patients were multiparous. Live births occurred in 6 patients and stillbirths in 5 patients. Hemorrhage, preeclampsia-eclampsia and pulmonary embolism were the leading causes of maternal death.

Cross-Cultural Comparison↗
PubMed1993

Does low-dose, transdermal, norethisterone acetate reliably cause endometrial transformation in postmenopausal oestrogen-users?

In a prospective study, the symptomatic, psychological and endometrial effects of a combined oestradiol/progestogen transdermal therapeutic system which delivers a low daily dose of norethisterone acetate have been investigated in 18 postmenopausal women. Treatment was given in 28 day cycles. Patients received transdermal oestradiol 50 micrograms/day continuously and transdermal norethisterone acetate, 0.1-0.15 mg/day, was added for 14 days. Treatment was given for between 5 and 7 cycles. One patient discontinued therapy because of a skin reaction. Low dose, transdermal norethisterone acetate caused few adverse symptomatic or psychological side-effects and appeared well tolerated. Fourteen endometrial samples were obtained during the combined (norethisterone acetate/oestradiol) phase of the 5th, 6th or 7th treatment cycle. None showed hyperplastic or malignant change but proliferative endometrium, indicative of an inadequate progestational stimulus, was observed in 4 biopsy samples. Three of these patients had reported breakthrough bleeding during therapy. For these reasons, we regard this dose of transdermal norethisterone acetate as inadequate in combination with transdermal oestradiol 50 micrograms/day for routine use in postmenopausal oestrogen users.

Administration, Cutaneous↗
PubMed1993

Patient assessment. Infection in the elderly.

1. Along with a decrease in immune competence, older adults are found to have reduced sensitivity of several homeostatic mechanisms that will also predispose them to the development of infection. 2. Common infections in the elderly include pneumonia, tuberculosis, urinary tract infections, and skin infections. 3. Nursing can play a pivotal role in the prevention of infection in the older adult by providing information on the importance of influenza and pneumococcal vaccines, instituting early risk assessment identification, and developing proactive nursing interventions for those individuals at risk.

Aged↗
PubMed1993

Birthweight curves in southern Israel populations.

With the aim of establishing a standard range of birthweights at different gestational ages for Jewish and Bedouin populations, we analyzed 5.5 years of computerized delivery files. Strictly confirmed gestational age was required in this study. This is necessary for proper diagnosis of growth abnormalities, such as growth retardation and macrosomia, for research purposes and for assessment of perinatal morbidity and mortality at a given gestational age. Percentile distributions of birthweights of 46,529 infants are presented. The mean birthweight of male infants was 3,238 g (SD 529 g) and of female infants was 3,117 g (SD 504 g). From week 36 to week 41 of gestation, infants of Jewish mothers were significantly heavier than infants born to Bedouin women, particularly in primiparous women. In both Jewish and Bedouin births, male infants were significantly heavier than female infants after the 36th week of gestation, by 130 g in the former and 127 g in the latter. Although the set of birthweight percentile curves of Jews and Bedouins was similar to the Colorado birthweight curve, some differences were found. At 41 and 42 weeks of pregnancy our infants were heavier and exceeded the standard, whereas at weeks 35 to 38 the standard exceeded the median weight of the Bedouin infants. The differences between our population curves and the commonly used Colorado standard curve emphasize the need for locally based and periodically updated infant birthweight data.

Birth Weight↗
PubMed1993

The association between increased mean arterial pressure and abnormal uterine artery resistance to blood flow during pregnancy.

OBJECTIVE: To examine the relation between increased mean arterial pressure (MAP) and the uterine artery resistance index (RI) to blood flow in the third trimester of pregnancy. METHODS: One hundred consecutive patients in the third trimester whose pregnancies were complicated by hypertensive disorders, with or without proteinuria, had uterine artery resistance to blood flow measured using continuous-wave Doppler. RESULTS: The RI was in the normal range in 20 patients. Unilaterally abnormal RI was found in 32 and bilaterally abnormal RI in 46 (two subjects were excluded from this categorization because measurements were obtained from only one side of the uterus). A MAP below 100 mmHg was associated with a normal RI. All six subjects with MAP of 140 mmHg or greater had bilaterally abnormal RI. Mean arterial pressure values of 100-139 mmHg included 90% of the women with normal RI, 100% of those with unilaterally abnormal RI, and 87% of those with bilaterally abnormal RI. Proteinuric and nonproteinuric groups differed with respect to both MAP (P = .04) and RI (P = .01). Pregnancy outcome was less favorable in the unilaterally abnormal RI subgroup than in the normal RI subgroup. The bilaterally abnormal subgroup of patients had the most adverse pregnancy outcomes. CONCLUSIONS: Pregnant patients in the third trimester who have increased MAP but a normal uterine artery RI can expect a good pregnancy outcome. Increased MAP associated with abnormal uterine artery RI may result in an unfavorable pregnancy outcome, particularly in those with bilaterally increased RI to blood flow. Doppler measurement of uterine artery impedance is recommended in pregnancies complicated by hypertensive disorders.

Adult↗
PubMed1992

Intensive surveillance for infections in a three-year study of nursing home patients.

The authors report the results of a 3-year (August 1984-May 1987) prospective study of intensive surveillance for nursing home-associated infections in 666 patients in a 300-bed nursing home in San Diego, California. Ninety-three percent (666 of 714) of the eligible subjects enrolled; 75% were women. The mean age of the subjects was 81.6 years. Lengths of stay ranged from 1 day to 1,025 days, with a mean of 166 days; the cumulative length of stay for all subjects was 110,746 days (303 years). Operational definitions that were heavily dependent on evaluation of clinical signs and symptoms were used by nurse practitioners in weekly or biweekly assessments of all patients to identify infections. The overall incidence of nursing home-associated infection was 7.1 infections/1,000 patient-days. Many of the infections would not have been recognized by persons less skilled than nurse practitioners. Among the 788 nursing home-associated infections identified, 362 (47%) were in the respiratory tract (286 lower respiratory and 76 upper respiratory); 200 (25%) were associated with skin and subcutaneous and mucous membranes; 140 (18%) were symptomatic urinary tract infections; 13 (2%) were bacteremia; and 73 (9%) were other infections.

Adult↗
PubMed1992

[Screening for colorectal cancer and polyps].

Screening programs for the early detection of colorectal neoplasms may prevent cancer or improve its prognosis. We screened 1101 individuals (89% of whom were asymptomatic) using 3 methods. The fecal occult blood test, done in 96% of those screened, was positive in only 1.9% and was low in both sensitivity (2.1%) and positive predictive value (6.7%). However, flexible sigmoidoscopy, performed in 48%, gave positive results in 7.8% of those screened, revealing 41 cases of polyps and 1 of cancer. Colonoscopy was performed in 8% and 37 cases of polyps and 1 of cancer were detected. Of the 3 screening methods tested, sigmoidoscopy appeared to be the best because of its high diagnostic yield. The risk of colorectal neoplasm was shown for the first time to be equal in Jews of oriental and occidental origin.

Colonoscopy↗
PubMed1992

Human histidyl-tRNA synthetase: recognition of amino acid signature regions in class 2a aminoacyl-tRNA synthetases.

We have determined the sequence of cDNA for the human histidyl-tRNA synthetase (HRS) in a hepatoma cell line and confirmed it in fetal myoblast and fibroblast cell lines. The newly determined sequence differs in 48 places, including insertions and deletions, from a previously published sequence. By sequence specific probing and by direct sequencing, we have established that only the newly determined sequence is present in genomic DNA and we have sequenced 500 hundred bases upstream of the translation start site. The predicted amino acid sequence now clearly demonstrates all three motifs recognized in class 2 aminoacyl-tRNA synthetases. Alignment of E. coli, yeast, and when available, mammalian predicted amino acid sequences for three of the four members of the class 2a subgroup (his, pro, ser, and thr) shows strong preservation of amino acid specific signature regions proximal to motif 2 and proximal to motif 3. These probably represent the active site binding regions for the proximal acceptor stem and for the amino acid. The first two exons of human HRS contain a 32 amino acid helical motif, first described in human QRS, a class 1 synthetase, which is found also in a yeast RNA polymerase, a rabbit termination factor, and both bovine and human WRS, suggesting that it may be an RNA binding motif.

Amino Acid Sequence↗
PubMed1992

[Resistance in uterine arcuate arteries of pregnant hypertensive patients].

Hypertensive pregnant women were examined by continuous Doppler-ultrasound to measure resistance to blood flow in the uterine arcuate arteries. 20/26 had increased resistance. Those with bilateral increased resistance delivered after a mean of 33.2 weeks of pregnancy, 46.1% of them by cesarean section, and the mean birthweight was 1743 g. Those with unilateral increased resistance delivered after a mean of 38.0 weeks, 28.5% by cesarean section, and the mean birthweight was 2813 g. Measurement of blood flow by the Doppler method seems to be useful in the management of hypertensive disorders in pregnancy, as it helps to assess deficiency of the uterine circulation.

Arteries↗