Search PubMed⌕ Search

Biomedical subjects

H Thomas

Publications and source records attributed to H Thomas.

At least 271 records · Page 15Linked to original sources

Should women carry their antenatal records?

A study of women's views on carrying their medical records during their pregnancy was conducted in Cambridge in 1982. Eighty eight women who were given their full records were compared with a control group of 83 women who carried the traditional cooperation card, both groups answering postal questionnaires about the advantages and disadvantages of carrying their respective records. Most women found advantages in carrying the complete record, although it was too large to carry for practical purposes. Both groups experienced difficulty in understanding what was written on their cards.

Attitude to Health↗

A competitive binding assay for fructose 2,6-bisphosphate.

A new direct assay method for fructose 2,6-bisphosphate has been developed based on competitive binding of labeled and unlabeled fructose 2,6-P2 to phosphofructokinase. Phosphofructokinase (0.5-1.3 pmol protomer) is incubated with saturating concentrations (5.0-5.5 pmol) of fructose 2,6-[2-32P]P2 and samples containing varying concentrations of fructose 2,6-P2. The resulting stable binary complex is retained on nitrocellulose filters with a binding efficiency of up to 70%. Standard curves obtained with this assay show strict linearity with varying fructose 2,6-P2 in the range of 0.5 to 45 pmol, which exceeds the sensitivity of most of the previously described assay methods. Fructose 2,6-P2, ATP, and high concentrations of phosphate interfere with this assay. However, the extent of this inhibition is negligible since their tissue contents are one-half to one-tenth that examined. This new assay is simple, direct, rapid, and does not require pretreatment of tissue extracts.

Animals↗

The role of obstetric factors in perinatal mortality trends.

In the Perinatal Unit of the New Jersey Medical School, Newark the combined neonatal mortality and stillbirth rates declined from more than 51 per 1000 to less than 17 per 1000 between 1971 and 1983. This change is comparable to the reduction of perinatal mortality rates nationwide since the Second World War. Because the improvement in the fetal and neonatal survival rates occurred in a static population and against well identifiable changes in the structure, equipment, policies and management patterns of the obstetric unit, it was possible to assess the impact of various factors upon perinatal outcome. In the environment of this institution adherence to conservative concepts of obstetric management, avoidance of manipulative and extraction procedures, an increase of the rate of cesarean sections from about 7 to 15% and emphasis upon infection control appeared to be the crucially important factors. Antepartum sonography and fetal stress and non-stress testing significantly impacted upon the results. The role of intrapartum electronic monitoring was less clearly definable and seemed to be effective only in the hands of experienced physicians. The results did not seem to be adversely affected by the fact that the program de-emphasized invasive procedures, including fetal scalp pH sampling.

Adolescent↗

Effects of praziquantel on human intestinal flukes (Fasciolopsis buski and Heterophyes heterophyes).

Human intestinal flukes (Fasciolopsis buski and Heterophyes heterophyes) were treated with praziquantel in vivo or in vitro and then studied by transmission (TEM) and scanning (SEM) electron microscopy. F. buski worms recovered from patients, which had been cured by oral treatment of 1 X 15, 1 X 25 or 1 X 40 mg praziquantel/kg body weight, showed typical contraction and alterations together with vacuolization and bleb formation of their tegument. H. heterophyes worms recovered from an experimentally infected dog were incubated in media containing 1 microgram praziquantel/ml for 5-60 min. Their tegument showed lesions the extent and duration of which increased with exposure time, finally leading to death. The damage observed in vitro was very similar to that found in F. buski recovered from cured patients. The cure rate was very high when using 1 X 15 mg praziquantel/kg.

Animals↗

Use of leucocyte-poor blood components and HLA-matched-platelet donors to prevent HLA alloimmunization.

Recent studies have shown that the incidence of alloimmunization due to repeated platelet transfusions from random donors may be reduced by the use of leucocyte-poor blood components. These results were confirmed by this study, where 16% of patients with acute leukaemia undergoing initial chemotherapy and receiving leucocyte-poor blood components developed lymphocytotoxic antibodies, compared with 48% of patients in a control group receiving standard (non-leucocyte-depleted) blood components. In a third group, who received leucocyte-poor blood components and HLA-matched platelets, none of the patients developed lymphocytotoxic antibodies. There was a low incidence of platelet-specific antibodies (8%) but no difference between the three groups. Improved methods of removing leucocytes from blood components appear to offer the best approach for minimizing HLA alloimmunization, as the provision of HLA-matched platelet donors for prophylactic platelet support of all patients is not feasible.

Adolescent↗

Womens' views on keeping fetal movement charts.

This study reports the views of 132 women on filling in fetal movement charts during pregnancy. All appeared to have received an adequate explanation of how to fill in the chart. Although just over half the sample of women were reassured by filling in the chart, 23% were worried by it and 16% made other unfavourable comments on its use. Analysis of the comments made suggests that women are probably not given an adequate explanation for the reasons for keeping a kick chart regularly, or of the possible importance of a reduction in fetal activity.

Attitude to Health↗

Studies of the structure of fructose-6-phosphate 2-kinase:fructose-2,6-bisphosphatase.

Some physicochemical properties of a homogeneous preparation of a bifunctional enzyme, fructose-6-phosphate 2-kinase:fructose-2,6-bisphosphatase, were determined. The molecular weight of the enzyme is 101 000 as determined by high-speed sedimentation equilibrium. The molecular weight of dissociated enzyme is 55 000 in 6 M guanidinium chloride by sedimentation equilibrium and in sodium dodecyl sulfate by polyacrylamide gel electrophoresis. A value of 4.7 was observed for the isoelectric point. Tryptic peptide maps and high-performance liquid chromatography of the trypsin-digested enzyme revealed approximately 60 peptides. Amino acid analysis of the enzyme shows that it contains 27 lysine and 36 arginine residues per 55 000 daltons. No free N-terminal amino acid residue was detectable, suggesting that it is blocked. Hydrolysis of the enzyme by carboxypeptidases A and B releases tyrosine followed by histidine and arginine, indicating that the amino acid sequence at the carboxyl terminus is probably -Arg-His-Tyr. Tryptic digestion of [32P]phosphofructose-6-phosphate 2-kinase:fructose-2,6-bisphosphatase yields a 32P-labeled peptide detected by tryptic peptide mapping and high-performance liquid chromatography. Thermolysin digestion of CNBr-cleaved 32P-enzyme also yields a single 32P-peptide. These results indicate that fructose-6-phosphate 2-kinase:fructose-2,6-bisphosphatase is a dimer of 55 000 daltons and the subunits are very similar, if not identical.

Amino Acids↗

Effect of modification of lysine residues of fructose-6-phosphate 2-kinase:fructose-2,6-bisphosphatase with pyridoxal 5'-phosphate.

Inactivation of a bifunctional enzyme, fructose-6-P,2-kinase:fructose-2,6-bisphosphatase by pyridoxal 5'-P followed by reduction with NaBH4 was studied. Fructose-6-P,2-kinase is over 80% inactivated by 2 mM pyridoxal 5'-P. The stoichiometry of the pyridoxyl-P incorporation and the inactivation of the kinase follows a biphasic curve. The first P-pyridoxyl residue incorporated per protomer does not affect fructose-6-P,2-kinase, but the next two P-pyridoxyl incorporation/protomer results in 80% inactivation. The Km values for ATP and fructose-6-P of the enzymes containing varying amounts of P-pyridoxyl groups at intermediate levels of inactivation are not altered, but Vmax is decreased. Among the metabolites tested, only fructose-2,6-P2 and Mg-ATP are competitive with pyridoxal-P and protect the enzyme against the inactivation. Neither the activity nor the fructose-6-P inhibition of fructose-2,6-bisphosphatase is affected by the modification. The acid hydrolysate of the inactive P-[3H]pyridoxyl enzyme contained only [3H]pyridoxyl lysine. High performance liquid chromatography of tryptic peptides of phospho[3H]pyridoxyl enzymes reveals two peptides which were missing in the enzyme protected by fructose-2,6-P2 or ATP during the modification reaction. These peptides have been isolated, and their amino acid sequences have been determined as Asp-Gln-Asp-Lys-Tyr-Arg and Asp-Val-His-Lys-Tyr. Pyridoxal-P reacts specifically with two lysine residues at the fructose-2,6-P2-binding site of fructose-6-P,2-kinase but not that of fructose-2,6-bisphosphatase. The site may also overlap with the ATP-binding site.

Adenosine Triphosphate↗

Multiple daily fractionated radiation therapy and misonidazole in the management of malignant astrocytoma. A preliminary report.

Various attempts have been made to improve the effectiveness of radiation in the treatment of cerebral malignant astrocytomas. A trend favoring multiple daily fractionated (MDF) radiation therapy over conventional single daily fractionated (CF) radiation therapy was identified in our previous study. In order to assess the effect of MDF with and without misonidazole, a province-wide prospective randomized trial was initiated in January 1981. By March 1984, 124 patients with histologically verified grade III and IV astrocytomas were randomized to CF (5800 cGy/6 weeks/30 fractions), MDF (6141 cGy/4.5 weeks/69 fractions at 89 cGy every 3-4 hours, three times a day) and MDF in combination with misonidazole (1.25 g/m2 three times weekly for the first 3 weeks). Thirty-eight patients were randomized to CF, 43 patients to MDF, and 43 patients to MDF and misonidazole. At the preliminary assessment in July 1984, the median survival time was 27 weeks for the CF group, 39 weeks for the MDF group and 49 weeks for MDF and misonidazole group. The 1-year actuarial survival rate from surgery was 20% for CF group, 41% for MDF group, and 45% for MDF and misonidazole group. There is a statistically significant difference (P less than 0.001) between the CF and MDF group. However, the addition of misonidazole does not significantly alter survival.

Adolescent↗

Separation of the catecholamine metabolites 4-hydroxy-3-methoxy- and 3-hydroxy-4-methoxymandelic acid by reversed-phase high performance liquid chromatography.

The catecholamine metabolites 4-hydroxy-3-methoxy- and 3-hydroxy-4-methoxymandelic acid can be completely separated by reversed-phase high performance liquid chromatography with chemically bonded octadecylsilane as stationary phase and a citrate/ammonium phosphate buffer (pH 4.5) containing 8% methanol as mobile phase. The two isomers can be electrochemically detected and produce different hydrodynamic voltammograms.

Catecholamines↗

[Direct quantitative determination of LDL cholesterol and HDL cholesterol using agarose gel electrophoresis].

The direct and quantitative determination of the main classes of the serum lipoproteins by means of a simple and reliable method is an urgent necessity for answering the numerous clinical questions. By precipitation of polyanions of the lipoproteins after electrophoretic separation in the agarosegel it is possible to determine sufficiently exactly and reproducibly their concentration without ultracentrifugation. For HDL- and LDL-cholesterol (beta-und alpha-lipoprotein cholesterol) a serial precision of 3 and 4%, respectively, and day,/day of 4 and 6%, respectively, was found. The methodology is described in detail and the problems of the establishment of the reference curves are particularly entered. In addition to this the determination of LDL- and HDL-cholesterol and beta- and alpha-lipoprotein cholesterol, respectively, was performed in sera of patients according to 3 and 4 variants, respectively, and these results were correlated with the densitometer surfaces of the beta- and alpha-lipoproteins. The correlation coefficients were between 0.94 and 0.99.

Arteriosclerosis↗

Misonidazole combined with hyperfractionation in the management of malignant glioma.

Multiple daily fractionated radiation therapy (MDF) may be more effective than conventionally fractionated radiation therapy (CF) in the treatment of malignant glioma. The hypoxic cell sensitizer misonidazole (MISO) could be more effective when employed with small fractions of radiation every 4 hours to take advantage of the long half-life of the drug. To evaluate MDF and MDF in combination with MISO, a randomized prospective trial was initiated. Between January 1981, and December 1982, patients with histologically verified astrocytoma with anaplastic foci or glioblastoma multiforme were randomized to CF (5800 cGy, 30 fractions, 6 weeks), MDF (6141 cGy, 69 fractions, 4 1/2 weeks, at 89 cGy every 4 hours 3 times daily) and MDF in combination with MISO (1.25 gm/M2 three times weekly for the first 3 weeks). In January 1983, the CF arm was dropped and a high dose MDF arm added (7120 cGy, 80 fractions, 5 1/2 weeks, at 89 cGy per fraction every 4 hours 3 times daily). CCNU chemotherapy was given at the time of tumor progression. One hundred and twenty-eight patients were evaluated (38 CF, 42 MDF, 37 MDF plus MISO, and 11 high dose MDF). Median survival was 29 weeks for CF, 45 weeks for MDF and 50 weeks for MDF plus MISO. Survival was significantly improved for patients treated with MDF compared to patients treated with CF (p less than .002). The addition of MISO to MDF did not result in further improvement in survival. Acute toxicity was acceptable. No clinically apparent delayed toxicity was observed.

Adolescent↗

Community antenatal care--a local study.

Views of 16 general practitioners and 14 midwives on "shared antenatal care" revealed local differences in organization, in policy, in the roles of the professionals involved, and in the level of communication and co-operation between them.

Community Health Services↗

[2-(Guanidino)-anilides and related compounds. Synthesis and anthelmintic effect. 3. Anthelmintics].

Anilides bearing a guanidino, thioallophanato, isothioallophanato or amidino group in the ortho position were synthesised (6) for investigations of their anthelmintic effects, and tested against sheep trichostrongylides. The most active anilides are those containing a 5-alkylthio, 5-alkylsulphinyl (alkyl = C3H7, C4H9), 5-phenylthio, 5-phenylsulphinyl or 4-phenylsulphonyloxy group, and a guanidino group substituted at both nitrogen atoms by a methoxycarbonyl group. The most active anthelmintic anilides are the form-, propion-, butyr- and methoxy-acetanilides (e.g. 60, 61, 66, 95, 100, 110). Of the guanidines unsubstituted at N' and N", the 2-guanidino-5-phenylthio-2-methoxyacetanilide (123) and the 2-guanidino-5-phenylsulphinyl-2-methoxyacetanilide (152) were more active than parbendazole. From the class of bismethoxycarbonylguanidines (6 alpha), which are also the most interesting products in terms of stability, febantel (110, Rintal) has been introduced into veterinary practice for the treatment of nematode infections in horses, cattle, sheep and swine.

Aniline Compounds↗