Characterisation of a chromatin fraction bearing pulse-labelled RNA. 1. Nascent RNA, RNA polymerase B and transcribed DNA sequence content

We have further characterised a fraction of polynucleosomal chromatin from mouse cells which is enriched in transcribing regions, after separation by multistep partition in a dextran /poly(ethylene glycol) two-phase mixture [Faber, A. J. (1972) Methods Cell Biol. 16, 447--457]. This fraction contains an average of 16% of the total DNA and 63% of the 3-min pulse-labelled RNA in chromatin which, by a number of criteria, represents nascent RNA transcripts. Of the total transcribing RNA polymerase B molecules in chromatin, 52% are found in this fraction by titration with radioactive alpha-amanitin. About 28% of the single-copy DNA sequences in this fraction hybridise to nuclear polyadenylated RNA, compared with only 1.5% of the single-copy sequences in the remaining (nontranscribing) chromatin fraction.

Computerized tomography in the measurement of femoral anteversion in legg-calve perthes disease

This article reviews the method by which computerized axial tomography is utilized in the management of femoral anteversion, and the use of this method in Legg Perthes disease.

Family studies of hypergastrinemic, hyperpepsinogenemic I duodenal ulcer

Antral G-cell hyperfunction is a rare cause of hypergastrinemia, hyperchlorhydria, and duodenal ulcer disease. We found evidence for a familial basis for this disorder. The probands were two young men with aggressive duodenal ulcer who had basal and postprandial hypergastrinemia, hyperpepsinogenemia I, and basal and pentagastrin-stimulated hyperchlorhydria. All characteristics returned to normal after antrectomy and vagotomy. Antral gastrin concentrations and quantitative G-cell counts were normal, indicating hyperfunction of G-cells rather than hyperplasia. Four of 10 first-degree relatives of the two patients shared with them the combination of postprandial hypergastrinemia and hyperpepsinogenemia I. The aggregation of these abnormalities in tow families, each identified by a proband with hypergastrinemic, hyperpepsinogenemic l duodenal ulcer, suggests that antral G-cell hyperfunction may have a genetic basis.

Effect of supplementary food on suckling patterns and ovarian activity during lactation

Patterns of infant feeding, basal prolactin concentrations, and ovarian activity were studied longitudinally in 27 breast-feeding mothers from delivery until first ovulation. Suckling frequency (6.1 feeds/day) and suckling duration (122 mins/day) reached peak values four weeks post partum and remained relatively constant until the introduction of supplementary food at a mean of 16 weeks post partum. There were subsequently sharp declines in both the frequency and duration of suckling, both of which correlated closely with basal prolactin concentrations. None of the 27 mothers ovulated during unsupplemented breast-feeding, but within 16 weeks of introducing supplements ovarian follicular development had returned in 20 and ovulation in 14 mothers. The mothers who ovulated within 16 weeks of giving supplements had reduced frequency and duration of suckling more quickly and weaned more abruptly than those who continued to suppress ovulation. These data suggest that the introduction of supplementary food may exert an important and hitherto unrecognised effect on the timing of first ovulation by reducing the frequency and duration of suckling episodes.

Sites of suicidal gunshot wounds

Two hundred twenty-six suicides by firearms were analyzed to determine the entrance wound site. Overall, the head was the most favored site, accounting for 75% of the wounds; specifically, the right temple accounted for 39% of the wounds. The data were further examined in terms of specific weapon types. In the case of handguns, the preference for the temple was even more prominent, with this site accounting for nearly two thirds of the wounds. With long guns the predominance of head wounds was less pronounced but still present. Correlations with sex and age showed no significant difference in choice of site but did show differences in selection of gunshot as the means of suicide. Correlations of site with handedness showed that most individuals held true to form but that a significant proportion (8%) inflicted their wounds on the other side. Finally, three cases of suicide by multiple gunshots are presented.

Treatment of acute focal cerebral ischemia with dimethyl sulfoxide

The object of this investigation was to study the effects of dimethyl sulfoxide (DMSO) upon the evolution of cerebral infarction. Twenty adult cats anesthetized lightly with ketamine hydrochloride underwent right middle cerebral artery occlusion for 6 hours. Ten cats were not treated and 10 cats received DMSO (2.5 g/kg i.v.) immediately after occlusion. Regional cerebral blood flow (rCBF) changes in the right sylvian region were similar in the untreated and treated groups. The mean rCBF before occlusion was 46 +/- 10 ml/100 g/minute in the untreated group and 45 +/- 10 ml/100 g/minute in the treated group. Eight cats in both groups had rCBF measurements consistently below 18 ml/100 g/minute during the 6-hour period after occlusion. An index of erythrocyte flow was determined by measuring the transit of technetium-99 (99Tc)-labeled erythrocytes in the right sylvian region. The period of erythrocyte transit before occlusion was 10 +/- 1 seconds in the untreated group and 10 +/- 2 seconds in the treated group. After 6 hours of occlusion, the erythrocyte transit time was 18 +/- 3 seconds in the untreated group and 19 +/- 3 seconds in the treated group. Increasing delay in erythrocyte transit during the 6-hour occlusion period was seen in 5 untreated cats and 6 treated cats and was thought to represent a progressive increase in microvascular resistance. The complete washout of erythrocytes indicated the absence of microcirculatory obstruction. Electroencephalography (EEG) showed a reduced amplitude of activity in the right cerebral hemisphere after occlusion in cats with an rCBF consistently below 18 ml/100 g/minute. No significant EEG differences were found between the untreated and treated groups. Treatment with DMSO failed to modify the developing ischemia edema, neuronal alterations, or the changes in blood-brain barrier permeability to Evans blue dye and fluorescein. In this study DMSO was ineffective in preventing ischemic damage or acted when irreversible injury had already taken place.

In-111-labeled leukocytes in the diagnosis of rejection and cytomegalovirus infection in renal transplant patients

Indium-111-labeled (In-111) leukocytes have been shown to be useful in the localization of inflammatory processes, including renal transplant rejection. Using previously reported labeling methods, 63 studies with this agent have been performed in 53 renal transplant patients. Indications for study included suspected rejection or cytomegalovirus (CMV) infection. Studies were performed in 33 men and 20 women, with ages ranging from 6 to 68 years. Autologous cells were normally used for labeling, although leukocytes obtained from ABO-compatible donors were used in three subjects. Rectilinear scanner and/or scintillation camera images were obtained at 24 hours after intravenous administration of 0.1 to 0.6 mCi of In-111-leukocytes. There was abnormal uptake of In-111-leukocytes in the transplanted kidney in 11 of 15 cases of rejection. In three additional cases of increased transplant uptake, CMV infection was present in two. Abnormal lung uptake was present in 13 of 14 patients with CMV infection. In four additional cases, increased lung uptake was associated with other pulmonary inflammatory disease. Increased lung activity was not seen in patients with uncomplicated transplant rejection. These results suggest that In-111-leukocyte imaging may be useful in the differential diagnosis of rejection versus CMV infection in renal transplant patients.

Microcirculatory obstruction in focal cerebral ischemia: albumin and erythrocyte transit

The objectives were to study plasma and erythrocyte flow in an area of acute focal cerebral ischemia and define their relationship to developing microcirculatory obstruction as determined by morphological techniques. Eighteen adult cats, anesthetized with ketamine hydrochloride, had right middle cerebral artery (MCA) occlusion. Plasma flow was determined by measuring the transit of Iodine-131 (131I) albumin and erythrocyte flow was determined by measuring the transit of Technetium-99 (99Tc) labeled erythrocytes in the right Sylvian region. Transit studies were performed before and immediately after right MCA occlusion and at the end of the ischemic period, 1 hour, 3 hours, or 6 hours after occlusion. Intra-arterial perfusion with a buffered formaldehyde - colloidal carbon solution was carried out after completion of the isotope studies. Swelling of cerebral tissue and impaired carbon filling in the right MCA territory were seen initially after 3 hours occlusion and were more severe after 6 hours occlusion. Ischemic neuronal alterations, edema formation, and capillary luminal narrowing increased with longer periods of occlusion. 131I albumin transit time in the right Sylvian region was 8 +/- 2 seconds before occlusion and 10 +/- 2 seconds immediately after occlusion. 99Tc erythrocyte transit time was 10 +/- 2 seconds before occlusion and 12 +/- 3 seconds immediately after occlusion. 99Tc erythrocyte transit time was 10 +/- 2 seconds before occlusion and 12 +/- 3 seconds immediately after occlusion. Transit times increased progressively with longer periods of occlusion in cats developing cortical ischemic changes. No evidence of complete microcirculatory obstruction to albumin and erythrocyte transit was seen in cats with 6 hours of occlusion despite the impaired filling of the cortical microcirculation with carbon. There were no findings to substantiate the hypothesis that plasmapheresis develops during the early phases of cerebral infarction.

How long should a breast feed last?

Patterns of milk flow were studied in 50 mothers who were breast-feeding normal birth-weight babies on days 5-7 of the puerperium by progressive test weighing at 5-min intervals during two consecutive feeds. Compared with a regime in which mothers attempted to feed for 10 X 10 min on alternate breasts, a regime of 5 X 5 X 5 X 5 min increased the amount of milk taken in the first 10 min did not influence the final milk intake of the suckling-induced prolactin release. The wide variation of breast-feeding patterns between mothers was demonstrated in respect of the duration of the feed (mean 17.3 min; S.D. +/- 3.1; range 7-30 min), the initial rate of milk flow (mean 6 g/min; S.D. +/- 4.2, range 1-14 g/min) and the final milk intake (mean 70.9 g; S.D. +/- 20.5, range 42-125 g). The advice to breast-feed for 20 min was in appropriate for the majority of mothers because the nutritive feeding time was 15 min or less in 75% of the feeding episodes. The milk intake correlated with the initial rate of milk flow but not with the duration of the feed, the infant's birth weight, or the time since the last feed. It is suggested that the duration of a breast feed should be determined by the infant's response and not by an arbitrary time schedule.

The effects of sterilisation: a comparison of sterilised women with the wives of vasectomised men

In a follow-up study, women sterilised by tubal diathermy were compared with a matched group of wives of vasectomised men. Semi-structured interviews were given to a random sample drawn from a representative population. The couples were young with small families and did not have a high proportion of unplanned pregnancies or terminations. They had previously used contraception, mainly the pill or sheath. Most couples were entirely satisfied with the operation. Both groups showed an increase in pre-menstrual symptoms but there was only slight evidence that menstrual loss was affected by female sterilisation. The vasectomy couples had a higher frequency of sexual intercourse, few sexual problems and tended to have more satisfactory marriages. They had had more discussion of their decision to have the operation and the implications of counselling are considered.

Childhood lymphoma in southern Iran

A study of 81 childhood lymphomas diagnosed in the Department of Pathology of Pahlavi University Medical Center, Shiraz, Iran, encompassing all histologically diagnosed childhood lymphomas from the Fars Province, Southern Iran over a 14-year period (1963--1976) revealed a 3:1 male predominance and a 1:4 frequency compared to adult lymphomas. Peripheral lymphadenopathy at the initial physical examination was almost twice as common as deep node involvement. Comparison of cumulative and age-standardized (to world population) incidence rates with those of selected Tumor Registries in various continents revealed a higher rate in our region of both non-Hodgkin's and Hodgkin's lymphoma relative to some of the Western countries. Our incidence rates were in general intermediate between Western populations on one hand and some South America, African and Asian populations on the other. Hodgkin's disease accounted for 64% (males) and 88% (females) of lymphomas and mixed cellularity was the commonest histologic subtype. Histologically almost all non-Hodgkin's lymphomas were diffuse at the time of diagnosis.

The attractiveness to males of female Drosophila melanogaster: effects of mating, age and diet

Decapitated females were used to examine the attractiveness to males (duration of courtship elicited) of female Drosophila melanogaster. Decapitated females show but few behavioural responses. The attractiveness of virgin females varied with age, being at a maximum on the day of eclosion, and declining thereafter. Even though decapitated inseminated females do not extrude their genitalia they received less courtship than decapitated virgin females. In protein-fed inseminated females attractiveness to males returned in parallel with sexual receptivity. A sucrose diet rendered both virgin and inseminated decapitated females more attractive to males, but did not prevent the change in attractiveness due to mating. The ejaculate and ovarian activation are suggested as causal factors in these processes.

Effect of an external heavy atom on the photochemistry of monofluorobenzene vapor

Spectrofluorometric techniques have been used to study the effect of added xenon on the singlet and triplet yields of monofluorobenzene vapor excited by 2670, 2520, and 2470 Å radiation. For each wavelength examined, the fluorescent yield was found to decrease with increasing xenon pressure and plots of 1/Фp vs.Pxe are linear. The sensitized emission of biacetyl technique was used to determine triplet yields. The effect of xenon on the emission yield of biacetyl excited directly at 4358 Å was also examined and it was found that xenon reduced the phosphorescent yield of biacetyl. Plots of 1/Φp vs. Pxe were found to be linear, for all cases of sensitized as well as directly excited emission. At 2470 Å both the fluorescence yield and the triplet yield initially increase with increasing Xe pressure, but when the Xe pressure exceeds about 30 Torr the behavior at this wavelength is the same as it is at the other two wavelengths.The data suggest that xenon enhances intersystem crossover in both monofluorobenzene (FB) and biacetyl (BiA). The important process in the former is 1FB + Xe → 3FB + Xe, while in the latter is 3BiA + Xe → BiA + Xe. A mechanism consistent with the experimental observation is presented.