Transition from initiation to promoter proximal pausing requires the CTD of RNA polymerase II.

The C-terminal domain (CTD) of mammalian RNA polymerase II consists of 52 repeats of the consensus hepta-peptide YSPTSPS, and links transcription to the processing of pre-mRNA. Although Pol II with a CTD shortened to five repeats (Pol II Delta5) is transcriptionally inactive on chromatin templates, it is not clear whether CTD is required for promoter recognition in vivo. Here, we demonstrate that in the context of chromatin, Pol II Delta5 can bind to the c-myc promoter with the same efficiency as wild type Pol II. However, Pol II Delta5 does not form a stable initiation complex, and does not transcribe promoter proximal sequences. Fluorescence recovery after photobleaching (FRAP) experiments with cells expressing enhanced green fluorescent protein (EGFP)-tagged Delta5 or wildtype Pol II revealed a single, highly mobile Pol II Delta5 fraction whereas wildtype Pol II yielded less mobile fractions. These data suggest that CTD is not required for promoter recognition, but rather for subsequent formation of a stable initiation complex and isomerization to an elongation competent complex.

Conditional expression of RNA polymerase II in mammalian cells. Deletion of the carboxyl-terminal domain of the large subunit affects early steps in transcription.

The carboxyl-terminal domain (CTD) of the large subunit of mammalian RNA polymerase II contains 52 repeats of a heptapeptide that is the target of a variety of kinases. The hyperphosphorylated CTD recruits important factors for mRNA capping, splicing, and 3'-processing. The role of the CTD for the transcription process in vivo, however, is not yet clear. We have conditionally expressed an alpha-amanitin-resistant large subunit with an almost entirely deleted CTD (LS*Delta5) in B-cells. These cells have a defect in global transcription of cellular genes in the presence of alpha-amanitin. Moreover, pol II harboring LS*Delta5 failed to transcribe up to the promoter-proximal pause sites in the hsp70A and c-fos gene promoters. The results indicate that the CTD is already required for steps that occur before promoter-proximal pausing and maturation of mRNA.

Possible toxicity of herbal remedies.

Herbal remedies are rapidly gaining popularity throughout the world as a result of dissatisfaction with conventional medicines. It is a widely held belief that herbal preparations are "natural" and are therefore intrinsically harmless. However, their effects can be very powerful and potentially lethal if used incorrectly and their use as a substitute for conventional medicines may be ineffective. Toxic effects have been attributed to several factors including hepatotoxicity of main constituents, contamination of preparations by heavy metals or microorganisms, and adverse reactions due to age, and genetic and concomitant disease characteristics of the user.

Utilisation of maternity services by black women in rural and urban areas of the Orange Free State.

An epidemiological survey was undertaken to evaluate the utilisation of maternal services for black women in the Orange Free State. Two hundred and forty clusters were selected from the rural (farms) and urban (local authorities) black population and eight households were interviewed in each cluster. Information was gathered from 237 rural women (from 959 households) and 168 urban women (from 926 households) who had delivered a baby or aborted during the preceding year. Antenatal care was received by 71% of the rural women and 87% of the urban women. Rural women delivered at home in 60% of cases while 37% delivered in hospitals. Only 23% of urban women delivered at home while 67% of their deliveries were conducted in hospitals. Nurses supervised deliveries in both instances in more than 60% of cases, but in rural areas traditional midwives managed 26% of the confinements. The conclusions are that the maternity service was largely provided by nurses and was predominantly limited to hospitals and homes. It is recommended that the quality of service be upgraded and more emphasis placed on midwife obstetric units.

Prevalence of vaginitis, syphilis and HIV infection in women in the Orange Free State.

OBJECTIVE: To determine the prevalence of vaginitis, syphilis and HIV infection in women in the Orange Free State. METHOD: By cluster sampling, 120 rural (farm) and 120 urban (local authority) clusters, each containing 4 women, were selected. Women aged 18-49 years who were included in the study had a cervical smear taken for cytological evaluation and blood specimens drawn for syphilis and HIV testing; they were questioned on their knowledge of AIDS. RESULTS: Trichomonas vaginalis vaginitis was present in 27.4% of the rural women and 29.6% of the urban women, Gardnerella vaginalis in 7.2% and 8.4% and Candida spp. in 2.6% and 6.7% respectively. Syphilis serology was positive in 12% of rural and 16% of urban women. HIV was present in 0.4% of rural and 1.5% of urban women. Ninety per cent of urban women and 74% of rural women knew AIDS was a sexually transmitted disease. CONCLUSIONS: The prevalences of trichomonas vaginitis and syphilis were unusually high, while HIV positivity was similar to that in other reports in South Africa.

Primary health care rendered from mobile units: can computers help?

The object of survey was to assess which aspects of the nurses' work in mobile clinics could be computerised with a beneficial effect on the quality of work. This paper is an analysis of how much time the nursing staff spent on various tasks. The results show that nurses are satisfied with their work, even in the face of difficult working conditions and a high workload. It was also found that computer and communications technology can promote greater efficiency in activities that represent 35% of a nurse's time.

Determining aspects of primary health care coverage in urban and rural areas of the Orange Free State.

The study was undertaken to determine the primary health coverage of blacks living in urban and rural areas of the Orange Free State. A multistage cluster sampling method was used to select 120 clusters in each of the urban and rural areas. The field work was conducted and completed in less than a week per region by nursing staff employed by health services rendering services in urban and rural areas. Interviews were conducted at 948 urban and 970 rural black households. Over 95% of the inhabitants had access to safe water, 50.9% of urban and 45.1% of rural children who had had an acute diarrhoeal attack appeared to have received adequate oral rehydration therapy, and 65.6% of children 12-23 months of age in urban areas and 38.1% in rural areas were considered fully immunised. The infant mortality rate was 45.3/1,000 in urban areas and 100.7 in rural areas. To reduce the infant mortality rates the World Health Organisation's programme for the control of diarrhoeal diseases has subsequently been introduced in the Orange Free State.

Long-term survival after postinfarction bypass operation: early versus late operation.

A study of 832 patients operated on within 30 days of infarction from 1974 to 1987 has resulted in 2,388 patient-years (maximum, 14 years) of prospectively acquired follow-up. This study excludes 74 patients in whom cardiogenic shock was the indication for operation. Five-year survival (+/- standard error) was 84% +/- 2%, 85% +/- 1%, and 90% +/- 1%, and 10-year survival was 71% +/- 4%, 68% +/- 1%, and 78% +/- 1% for patients with acute infarction, remote infarction, and no previous infarction, respectively. Age and left ventricular end-diastolic pressure significantly affected long-term survival for patients with acute infarction by both univariate and multivariate analysis. For patients aged less than 65 years, the 5-year and 10-year actuarial survival rates were 89% +/- 2% and 80% +/- 4%, compared with 75% +/- 3% and 58% +/- 9%, respectively, for patients aged more than 65 years. The survival percentages were 89% +/- 2% and 75% +/- 6% for patients with left ventricular end-diastolic pressure less than 15 mm Hg compared with 77% +/- 5% and 67% +/- 7% for patients with left ventricular end-diastolic pressure greater than 15 mm Hg. Operative mortality was 7.6% for patients operated on within 24 hours, compared with 4.1% for patients operated on between 2 and 30 days after infarction. Ten-year survival was similar (about 70%) for all timing groups. Based on these long-term results, there appears to be little to gain by delaying coronary artery bypass grafting, when indicated, after infarction occurs.

Early experience with the intraluminal graft prosthesis.

Surgical therapy for dissection of the thoracic aorta has been associated with a high mortality rate due in part to intraoperative bleeding at the suture lines and through the prosthesis. A technique has been devised to obviate some of these problems which utilizes a sutureless prosthesis that can be placed within the aorta. This device is now commercially available. Because of the infrequent use and the need to maintain a wide variety of lengths and diameters of these grafts, several Portland area hospitals jointly purchased grafts to reduce inventory and cost. From November 1981 through September 1982, four patients in two Portland area hospitals were treated with intraluminal grafts for descending thoracic dissections. All patients survived the surgical treatment and were discharged without complications. Based on a review of the literature and our initial experience, the intraluminal prosthesis appears to represent a significant improvement over conventional graft placement for treatment of both acute and chronic aortic dissection.

Errors in estimating slope spectra from wave images.

Slope spectral density resolved in wave number and direction is an important statistical descriptor of water surface waves. Experimentalists have estimated this descriptor from optical wave imagery by assuming that light from the surface is modulated linearly by the component of wave slope aligned with the imaging azimuth. The level of error arising from this assumption of linearity depends on the optical conditions and can be severe. We have numerically explored this error when only reflected radiance is imaged by using a synthesized sea surface and a clear sky model to simulate sea surface imaging. Additionally, we have developed a method for identifying geometries which minimize nonlinearity. This paper describes our analytic models, our numerical techniques, and the character of our results.

Visibility of rms slope variations on the sea surface.

A model relating viewing geometry, sky conditions, and statistical sea surface parameters to the luminance of the sea surface is developed. The model is used to estimate the relative visibility of surface perturbations manifested by a variation in the rms surface slope. These estimates are presented for a variety of geometries in the solar plane using two sky conditions (clear and overcast) and two wind speeds (~2 and 7 m/sec). The results of this analysis, applicable to a unidirectional radiometer with no temporal averaging, show comparable extrema in the visibility of surface perturbations for both the overcast and clear sky models. The visibility of surface perturbations is shown to be maximized by geometries with either large gradients in the slope-to-luminance transfer functions (within the glitter pattern for the clear sky and near the horizon for both sky models) or very small gradients in the slope-to-luminance transfer functions (90 degrees away from the glitter pattern for the clear sky and nadir directed for the overcast sky). It is shown that improvements in the estimated values of the luminance SNR sensitivity to rms surface slope variations can be obtained through spatial and/or temporal averaging.

Early surgical repair in traumatic rupture of the thoracic aorta (report of 9 cases and review of the current concepts).

Ten patients with rupture of the aortic isthmus due to blunt trauma were subjected to early surgical intervention with nine survivors (mortality 10%). A high degree of suspicion is necessary in order to make an early diagnosis. Left atrium (LA) to femoral artery (FA) bypass using systemic heparinization was used in all cases and bypass instituted before the aorta was prepared for clamping. Advantages of LA to FA bypass are as follows: (a) Technically easy; (b) Better control of patient during preparation of the aorta for clamping; (c) Provides the surgeon with more time to perform a safe operation.

Pulmonary embolectomy.

Embolectomy was carried out in eight patients with pulmonary emboli. Angiographic diagnosis was obtained in six, and in two cases pulmonary angiography could not be done because of the very critical condition of the patients. In the latter two, diagnosis was made based only on clinical findings. Two patients died in the operating room (25 percent). Six patients were discharged in good condition. It is emphasized that pulmonary embolectomy should be done in cases of pulmonary emboli when a clinical status of shock is present (systolic blood pressure less than 80 mm of mercury and the patient in low cardiac output syndrome) and when there is no response to medical treatment regardless of the degree of obstruction in the pulmonary arterial tree.

Late complications of aortic valve replacement with cloth-covered, composite-seat prostheses. A six-year appraisal.

Advanced actuarial techniques are used to analyze early and late results in a closely followed series of 396 patients who received a cloth-covered, composite-seat aortic prosthesis. Late mortality and various complications are carefully assessed, and most late deaths are seen to be unrelated to the prosthesis. One hundred sixteen patients with Model 2310-2320 prostheses who received warfarin postoperatively had no thromboembolic complications in 360 patient-years of follow-up (average, 3.1 years per patient); 134 patients who had the same prosthesis but did not receive warfarin had 9 emboli per 100 patient-years (average follow-up, 1.7 years per patient; total, 228 patient-years). By comparison, in 9 years' experience with non-cloth-covered Model 1200-1260 valves, 132 patients had 4.0 emboli per 100 patient-years (average follow-up, 5.1 years; total, 673 patient-years). The safety of cloth-covered valves is clearly enhanced by concomitant use of anticoagulants; the possibility that antiplatelet drugs may suffice has not yet been demonstrated. Strut cloth wear was found at reoperation in 10 patients. The Model 2400 composite strut ("track") valve with a narrow metal track on the inner surface of each strut prevents this complication.