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Biomedical subjects

D Parry

Publications and source records attributed to D Parry.

49 records · Page 3Linked to original sources
PubMed1985

Disposition in rats and mice of 7-methoxy-2-nitronaphtho[2,1-b]furan.

The disposition of 7-methoxy-2-nitronaphtho[2,1-b]furan (MNNF), labelled with 14C in the furan ring (label 1) and in the methoxy group (label 2) has been studied in rats and mice. After i.p. administration to rat (5 mg/kg), both labelled species were absorbed by the lymphatics; and after oral administration, through the intestinal lumen. Excretion of the furan ring (label 1) is mainly urinary (44% dose in 24 h); label 2 was mostly expired as 14CO2 (48% dose in 24 h), indicating considerable demethylation. No target organ was found for MNNF, except liver and kidney. For both labelled species given orally, radioactivity was bound to the intestinal wall. Preliminary metabolic studies, using t.l.c. and h.p.l.c., have shown the presence of an urinary metabolite, namely, the glucuronide of 7-hydroxy-2-nitronaphtho[2,1-b]furan (15-20% of the urinary radioactivity). The remaining radioactivity comprises basic compounds, that bind to a cationic resin, which might be formed by enzymic reduction of the nitro group.

Administration, Oral↗
PubMed1984

Nucleic acid metabolism in the nucleus and cytoplasm of angiosperm meiocytes.

Over the course of flowering plant evolution many important stages in the life cycle have become compressed into the period between the premeiotic mitosis and gamete maturation. For this reason the changes in structure or chemistry that take place at this time are not easily ascribed to particular 'developmental stages'. During the meiotic process itself striking changes occur in levels of cytoplasmic and nuclear RNA, while DNA is synthesized in both the chromosomes and organelles. Evidence is presented indicating that a large proportion of the m- and rRNA is purged from the meiocyte cytoplasm by a combination of normal degradation and the activity of specific hydrolases. DNA synthesis in both the plastids and mitochondria precedes the re-differentiation of these organelles, while that in the chromosomes occurs in two major peaks, as has previously been reported (Hotta & Stern, 1971). High-resolution autoradiography did not indicate either peak of DNA synthesis to be localized within the synaptonemal complex, although final confirmation of this conclusion must await further investigation. Examination of these events in organisms where meiosis is removed from other stages of the life cycle suggests that the degradation of RNA and the chromosomal DNA synthesis are features which regularly accompany the meiotic process. The significance of these findings is discussed in terms of the hypothesis that there is at least one stage in the life cycle of all plants at which a purge of information-carrying molecules takes place.

Cell Differentiation↗
PubMed1983

Changes in poly(a)+ RNA during male meiosis in Lilium.

Levels of poly(A)+ RNA have been investigated at each stage of male meiosis in Lilium (var. Firecracker). Two methods were employed in this work: in one extracts from labelled meiocytes were passed through oligo(dT) columns, while in the other the specific probe [3H]poly(U) was hybridized in situ with resin-embedded sections of pollen mother cells. The label contained in the eluate from the oligo(dT) columns was measured by liquid scintillation, and the quantity of [3H]-poly(U) hybridized was determined by statistical analysis of light microscopic autoradiographs. Both techniques revealed a dramatic decline in detectable poly(A)+ RNA during prophase. Lowest levels are reached in the pachytene stage, following which a gradual restoration of this species of RNA takes place in both nucleus and cytoplasm. The data presented here provide no clear indication as to whether this fall in RNA levels is caused by the action of novel enzymes specific to the meiotic prophase, by a cessation of synthesis and the activity of normal turnover processes, or by a combination of the two. Although there is some evidence from the [3H]poly(U) hybridization study that a small peak of poly(A)+ RNA synthesis may take place in leptotene, both methods indicate that there is a very low of poly(A)+ RNA synthesis throughout prophase. The presence of poly(A)+ RNA was not detected in either the accessory nucleoli or the cytoplasmic nucleoloids that characterize the nucleus and cytoplasm of these cells. These events are considered in terms of the juncture at which they occur in the plant life-cycle.

Meiosis↗
PubMed1982

The fetal soul.

Explore the source record for details and available documents.

Catholicism↗
PubMed1982

Ultrastructural and enzymatic development of fetal guinea pig heart.

The activities of some enzymes of glycolysis, the citric acid cycle, and amino acid metabolism have been measured in the fetal guinea pig heart over the last third of gestation and correlated with heart ultrastructural development. There is little change in glycolytic enzyme activity except for a two- to threefold increase in phosphofructokinase activity. Mitochondrial content and enzyme activities are low in the early fetal heart, and, although content is similar in the late fetus and adult, enzyme activities increase twofold postnatally, indicating fetal heart mitochondria are incompletely developed. The activities of aspartate and particularly alanine aminotransferase are low in the fetal heart. Over the last third of gestation the myofibrillar content of the fetal myocyte increases twofold to the adult value by term. Associated with this is a fourfold rise in myofibrillar and sarcoplasmic reticulum Ca2+-ATPase activity. Na+-K+-ATPase activity is similar in the late fetal and adult heart but one-third lower in the early fetal heart.

Adenosine Triphosphatases↗
PubMed1982

Distribution of 125I-labelled follicle-stimulating hormone and human chorionic gonadotrophin in the gonads of hypogonadal (hpg) mice.

Hypogonadal mice are deficient in LH releasing hormone (LH-RH), the releasing factor for LH and FSH, with a consequent failure of postnatal ovarian and testicular development. After intravenous injection of hypogonadal females with 125I-labelled human chorionic gonadotrophin (hCG), followed by autoradiography of semi-thin (1 micrometer) slices of the ovary, labelled hCG was found to be associated with interstitial cells and thecal cells with little or no labelling of granulosa cells. Labelled human FSH was associated solely with granulosa cells. Hypogonadal females, implanted for 5 days with a silicone elastomer capsule of oestrogen, showed a similar response to that of normal females with hCG labelling of the granulosa cells of the larger follicles as well as of the thecal cell layer. Furthermore, subcutaneous injection of hypogonadal females with LH-RH (50 ng), 12 times daily for 5 days, increased uterine weight and stimulated ovarian development with some large follicles binding hCG to both thecal and granulosa cells. Therefore stimulation of follicular development may possibly be associated with increased oestradiol concentrations. In the male, after injection of 125-I-labelled hCG, silver grains were associated with the interstitial cells alone in both hypogonadal and normal mice. Labelled human FSH was undetectable in semi-thin testicular sections, but the mode of injection (intravenous) not have allowed enough labelled hormone to reach the testis in order to resolve the question as to whether the hypogonadal or normal testis can bind FSH.

Animals↗
PubMed1976

Cholecystostomy.

The role of cholecystostomy in the sugical treatment of gallstones has been considered. In a consecutive series of 558 patients who underwent surgery for gallstones, 30 (5-4 per cent) had cholecystostomy alone and a further 17 (3-1 per cent) cholecystostomy combined with exploration of the bile ducts. Cholecystostomy was done because cholecystectomy was technically very hazardous in 15 patients. In the remaining patients cholecystostomy was preferred to cholecystectomy because o f the poor general condition of the patient or the presence of pancreatitis. Of the 47 patients submitted to cholecystostomy, 2(4-2 per cent) died postoeratively and 4(8-4 percent) subsequently underwent cholecystectomy. Of 24 patients who were available for long term follow-up, only 1 patient had pain which was definitely considered to be due to gallstones, although 3 other patients also had abdominal pain, while 7 patients showed radiological evidience of gallstones. It is contended that cholecystostomy has a small but definite part to play in the immediate surgical treatment of gallstones and that the long term results of the operation are sufficiently good to justify its use in selected patients.

Adult↗
PubMedDate not supplied

Effect of iron chelation therapy on mortality in Zambian children with cerebral malaria.

To examine the effect of iron chelation on mortality in cerebral malaria, we enrolled 352 children in a trial of deferoxamine in addition to standard quinine therapy at 2 centres in Zambia, one rural and one urban. Entrance criteria included age < 6 years, Plasmodium falciparum parasitaemia, normal cerebral spinal fluid, and unrousable coma. Deferoxamine (100 mg/kg/d infused for a total of 72 h) or placebo was added to a 7 d regimen of quinine that included a loading dose. Mortality overall was 18.3% (32/175) in the deferoxamine group and 10.7% (19/177) in the placebo group (adjusted odds ratio 1.8; 95% confidence interval 0.9-3.6; P = 0.074). At the rural study site, mortality was 15.4% (18/117) with deferoxamine compared to 12.7% (15/118) with placebo (P = 0.78, adjusted for covariates). At the urban site, mortality was 24.1% (14/58) with deferoxamine and 6.8% (4/59) with placebo (P = 0.061, adjusted for covariates). Among survivors, there was a non-significant trend to faster recovery from coma in the deferoxamine group (adjusted odds ratio 1.2; 95% confidence interval 0.97-1.6; P = 0.089). Hepatomegaly was significantly associated with higher mortality, while splenomegaly was associated with lower mortality. This study did not provide evidence for a beneficial effect on mortality in children with cerebral malaria when deferoxamine was added to quinine, given in a regimen that included a loading dose.

Antidotes↗
PubMedDate not supplied

When one is two.

This article is about Karen, who was 20 weeks pregnant when she was involved in a gas explosion. The explosion caused a 35% body surface area deep partial-thickness burn to her legs and arms. This article focuses on the most important concerns and fears Karen expressed while she was in our care. Her statements triggered various clinical memories from several nurses in the burn unit, and thus the stories unfold. These stories reflect nursing practice through the psychological care, clinical signs, and pathophysiology of our patient. The spoken stories, coupled with the reflective stories, provide a total picture of the multidimensional care nurses provide for their patients.

Analgesics↗