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Biomedical subjects

J Donovan

Publications and source records attributed to J Donovan.

At least 109 records · Page 6Linked to original sources
PubMed1986

Transplantation of the prepuce to facilitate hypospadias repair in monozygotic twins.

We report a case of free transplantation of the prepuce derived from a monozygotic twin to aid in the reconstruction of penoscrotal hypospadias in his brother. Although monozygotic twins discordant for hypospadias are seen rarely the possibility of preserving and transplanting the prepuce of the unaffected sibling should be considered to facilitate reconstruction of the phallus with hypospadias.

Circumcision, Male↗
PubMed1985

Intraoperative sonography of the pancreas.

Intraoperative sonography (IOS) of the pancreas was performed in 12 patients, eight with known or suspected inflammatory disease and four with known or suspected malignancy, in order to assess its utility in aiding pancreatic surgery. In all eight patients with inflammatory disease, IOS provided additional information, aided in resection or biopsy, or identified structures that could not be evaluated by surgical dissection. IOS was particularly useful in these patients in determining the size and appearance of the pancreatic duct before dissection or ductography, thus allowing planning of appropriate pancreatic decompression or resection. It also was extremely helpful in locating and characterizing pseudocysts, including measurement of cyst wall thickness, and in directing needle aspiration of cyst contents. Adequate drainage of all cysts in multiple cystic masses was easily monitored. Finally, impalpable peripancreatic fluid collections and abscesses were often localized. In the four patients with probable malignancy, IOS was somewhat helpful in two, allowing exclusion of tumor in one and guiding biopsy in another. In the other two patients, IOS provided no information due to obvious local invasion and nonresectability. Results indicate a significant adjunctive role for IOS in surgery for inflammatory disease of the pancreas. It seems to be less helpful in patients with malignancy, probably because of the advanced stage of pancreatic carcinoma at the time of surgery.

Adult↗
PubMed1984

Intravenous cis-platinum for invasive bladder cancer. Safety and feasibility of a new approach.

The five-year survival rate of patients with locally invasive bladder cancer (stages T3-T4, Nx, Mo) is less than 50% whatever treatment is given. In an effort to improve the prognosis of patients with this disease, we have incorporated into a management protocol two cycles of intravenous administration of cis-platinum before surgery or radiotherapy (which function as the "definitive" treatment). In 10 of the first 12 patients treated, tumour necrosis has been demonstrated histologically, and definite clinical responses have been observed in eight patients after two cycles of cis-platinum treatment. The toxicity has been acceptable, and subsequent management has not been compromised.

Adult↗
PubMed1984

Sarcomas of the uterine corpus: prognostic factors and treatment.

Twenty-eight patients with sarcomas of the uterine corpus were followed at least 22 months or until death. All underwent laparotomy, eleven had radiation therapy, and six had chemotherapy. Three year actuarial survival was 24%, and three year actuarial local control was 36%. Multivariate analysis demonstrated that, as with sarcomas at other sites, the most important factors influencing survival were grade (P = 0.020) and stage (P = 0.022). For local control, multivariate analysis indicated the most important factors to be stage (P = 0.001) and radiation TDF (P = 0.01). Of 21 failures, 16 involved the pelvis, seven involved the upper abdomen, and 11 involved distant sites. The importance of both local and distant disease control is emphasized.

Adult↗
PubMed1984

Alcohol consumption and outcome of pregnancy.

In a prospective study 1256 pregnant women at their first antenatal visit were asked if they drank alcohol every day, occasionally, or not at all, both at that time and before the diagnosis of pregnancy. There were no significant differences, among the three alcohol groups, in the proportions having miscarriages, perinatal deaths, congenital anomalies, or premature births. Women who reported drinking every day before pregnancy was diagnosed had heavier babies than those who did not drink at all, but there were no differences in mean birth weight according to alcohol use at the first antenatal visit. There were statistically significant differences among the three groups in important background characteristics, such as social class, age, smoking, and marital status. When adjustment was made for these factors, both occasional and daily consumption of alcohol before pregnancy appeared to have significantly positive effects on birth weight. These results illustrate the difficulty of evaluating the effects of alcohol in observational studies, and imply a need for caution in attributing either negative or positive effects of alcohol on the outcome of pregnancy.

Abortion, Spontaneous↗
PubMed1983

Phosphonoacetic acid-resistant RNA of Epstein-Barr virus in productively infected cells.

The transcription of Epstein-Barr virus genome in productively infected B95-8 cells in the presence or absence of phosphonoacetic acid (PAA) was studied. Twenty-eight species of cytoplasmic poly(A)-containing virus mRNA were identified as PAA resistant. Some of these viral mRNAs were not detected in the absence of PAA. The most actively transcribed fragments of cloned EBV DNA in the presence of PAA were BamHI H (map unit 29.1-32.5) and M (47.3-50.3). The treatment of TPA-induced B95-8 cells with cycloheximide abolished most cytoplasmic viral poly(A) RNAs, and only three species of viral mRNA (0.7, 1.0, and 1.6 megadaltons) were detectable by hybridization with the BamHI M fragment.

Animals↗
PubMed1982

In vitro and in vivo effects of vitamin E on arachidonic acid metabolism in rat platelets.

Preincubating platelet-rich plasma (PRP) of vitamin E-deficient rats with RRR-alpha-tocopherol prior to the aggregation induced by collagen suspension resulted in inhibition of the formation of endoperoxide metabolites derived from endogenous arachidonic acid (AA). This inhibition was not dose dependent at concentrations above the plasma level of RRR-alpha-tocopherol of vitamin E-supplemented rats. Preincubating the vitamin E-deficient PRP with RRR-alpha-tocopherol did not affect the formation of 12-hydroxyeicosatetraenoic acid, the platelet lipoxygenase product. Concentrations of endoperoxide metabolites in diluted whole blood challenged with collagen suspension were significantly greater in the vitamin E-deficient group than the supplemented group. The level of AA in platelet or plasma phospholipids was not different between the two groups. However, blood platelet counts in the deficient group were significantly greater than those of the supplemented group. Concentrations of endoperoxide metabolites in PRP samples in which platelet concentrations were equalized were still greater in vitamin E-deficient group; however, the difference was not statistically significant. There was also no difference in the degree of maximal platelet aggregation between the two groups. These results indicated that vitamin E deficiency can slightly stimulate the formation of cyclooxygenase products derived from endogenous AA, but it did not affect the formation of lipoxygenase product in rat platelets.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1979

Mechanistic studies with vinylglycine and beta-haloaminobutyrates as substrates for cystathionine gamma-synthetase from Salmonella typhimurium.

Cystathionine gamma-synthetase (EC 4.2.99.9), a key enzyme in bacterial methionoine biosynthesis, has been found to use L-vinylglycine (2-amino-3-butenoate) and L-beta-haloaminobutyrates (X = F, Cl) as substrates in addition to the physiological gamma-substituted substrate O-succinyl-L-homoserine (OSHS). Vinylglycine is a substrate both for alpha-ketobutyrate formation (the normal product from gamma elimination with OSHS) and for cystathionine formation (the normal gamma-replacement product with OSHS) in the presence of cysteine. This behavior substantiates that the stabilized vinylglycine--pyridoxal phosphate (PLP) alpha carbanion is the key partitioning species in this enzyme's catalysis. The Vmax values for ketobutyrate production and cystathonine formation from vinylglycine are equivalent at approximately 45 U/mg, whereas the corresponding Vmax values from OSHS are 20 and 200 U/mg, respectively, suggesting different rate-determining steps with these two substrates. The beta-haloaminobutyrates undergo catalyzed HX elimination to yield bound aminocrotonate--PLP directly as a an initial intermediate and as a precursor of ketobutyrate. Little or no cystathionine formation is detectable when these substrates are incubated with enzyme and the normal cosubstrate cysteine, strongly indicating that the aminocrotonate--PLP intermediate is not in rapid, reversible equilibrium with the stabilized vinylglycine--PLP carbanion; in normal catalysis, the prototropic shift from alpha carbanion to aminocrotonate appears functionally unidirectional. The HX-elimination step from beta-chloroaminobutyrate is nonconcerted as demonstrated by a 3H2O in equilibrium chloroaminobutyrate exchange reaction. Further suggestion for discrete beta-halo-alpha-carbanionic intermediates derives from the observation that the haloaminobutyrates appear to a partition between ketobutyrate formation and enzyme inactivation. Since neither vinylglycine nor OSHS causes any detectable inactivation during turnover, it is likely that the inactivation species is not a common intermediate, i.e., the electrophilic aminocrotonate--PLP species (a potential Michael acceptor), but rather a species peculiar to the beta-haloaminobutyrate pathway. The beta-halo-alpha-carbanion--PLP intermediate has beta-halo-alpha-iminodihydropyridine character in the p-quinoid resonance contributor and is a good candidate for an alkylating agent by an SN2--displacement mechanism. Spectroscopic analyses of incubations with the various amino acid substrates show a number of long-wavelength absorbing species forming during turnover, tentative assignments are suggested.

Aminobutyrates↗
PubMed1979

How doctors live with the spectre of ghost patients.

Describes the system of inbuilt 'inflation' that has evolved in maintaining GP patient lists. Although GPs are paid on a capitation basis, absolute accuracy is impossible and 'ghost patients' provide the necessary flexibility.

Capitation Fee↗
PubMed1975

Community noise criteria.

In the fields of community noise abatement and municipal planning, there are new requirements to define an environment of varying noise level by a single number rating method that correlates well with the subjective response of human beings. Typical criteria, either in use of proposed, are LN numbers (noise levels exceeded N% of the time), Leq (the equivalent sound level in dB(A) ), LNP (the Noise Pollution Level), and Ldn (the day-night average sound level in dB(A) ). Instruments available include an environmental noise classifier, a statistical distribution analyzer/recorder combination, and a digital sampling system for field measurements for subsequent interrogation by a programmable calculator.

City Planning↗