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C Mitchell

Publications and source records attributed to C Mitchell.

At least 91 records · Page 5Linked to original sources
PubMed1989

Proteins that interact with GTP during sporulation of Bacillus subtilis.

During sporulation of Bacillus subtilis, several proteins were shown to interact with GTP in specific ways. UV light was used to cross-link [alpha-32P]GTP to proteins in cell extracts at different stages of growth. After electrophoresis, 11 bands of radioactivity were found in vegetative cells, 4 more appeared during sporulation, and only 9 remained in mature spores. Based on the labeling pattern with or without UV light to cross-link either [alpha-32P]GTP or [gamma-32P]GTP, 11 bands of radioactivity were apparent guanine nucleotide-binding proteins, and 5 bands appeared to be phosphorylated and/or guanylated. Similar results were found with Bacillus megaterium. Assuming that GTP might be a type of signal for sporulation, it could interact with and regulate proteins by at least three mechanisms.

Bacillus subtilis↗
PubMed1989

A placebo-controlled dose-response study of enprofylline in the maintenance therapy of asthma.

We assessed the efficacy and side effects of oral enprofylline in the maintenance therapy of 206 asthmatics 19 to 71 yr of age. After a 1-wk placebo run-in, patients were randomized to receive in double-blind fashion one of three doses of slow-release enprofylline tablets (150 mg, 300 mg, or 450 mg twice daily) or matching placebo for 4 wk. At baseline, mean (SD) peak expiratory flow rate (PEFR) was 62 (19)% of predicted normal values. The mean increase in morning PEFR 12 h after dosing was: for 450 mg, 14(17)%; for 300 mg, 8(23)%; for 150 mg, 2(11)%, for placebo 0(10)%. The increases over baseline for 450 mg and 300 mg compared with 150 mg and placebo were statistically significant. The mean asthma symptoms score (scale zero to 3) exhibited a dose-related reduction. Significantly less beta 2-receptor agonist inhalations were used in the 450-mg group than in the placebo group. There was a statistically significant increase in headache and nausea with the doses 450 mg and 300 mg given twice daily during the first treatment week compared with 150 mg and placebo. Subsequent to the first week, there were no differences between the active treatments and placebo with respect to the incidence of these and other side effects. We conclude that oral enprofylline, in a dosage of 300 to 450 mg twice daily is an effective and well-tolerated drug that may be useful in the maintenance therapy of asthma.

Adult↗
PubMed1988

A simple inexpensive post-operative management regime following surgery for Dupuytren's contracture.

A simple regime has been devised for the post-operative management of patients following surgery for Dupuytren's contracture; this includes splintage of the hand for two weeks and active and passive mobilisation by the patient according to precise instructions. Selective help was provided by minimal occupational therapy in 5 of 50 patients. The results of the method were assessed prospectively by subjective criteria and objective assessment by measuring the deformity of the finger joints, lateral and tip pinch and grasp and shear forces.

Dupuytren Contracture↗
PubMed1988

Comparison of the effects of nebulized terbutaline with intravenous enprofylline in patients with acute asthma.

We compared the bronchodilating effects of intravenously administered enprofylline (2 mg/kg) with nebulized terbutaline (10 mg) in patients presenting to hospital with acute asthma in a multicenter double-blind parallel study. One hundred twenty three patients were randomized into the study, and 69 of these fulfilled the inclusion criteria and a retrospective time to study entry criterion; 34 received enprofylline and 35 received terbutaline. There was no significant difference in maximum increase in forced expired volume in 1 second (FEV1) between the enprofylline group (0.24 +/- 0.33 L) and the terbutaline group (0.25 +/- 0.28 L) (p greater than 0.05), nor for the increase in FEV1 over the 1-hour study period. Tremor was reported more in the group receiving terbutaline, and nausea was reported more in the group receiving enprofylline. Two patients experienced hypotension and one patient had a vasovagal episode with enprofylline treatment. Both agents acted as bronchodilators with similar efficacy in patients with acute asthma in this study.

Acute Disease↗
PubMed1988

Second malignant neoplasms in retinoblastoma. Fact and fiction.

Second malignant neoplasms (SMN) are distinct from primary neoplasms in site, time and histology. SMN may arise by chance or due to the influences of chemotherapeutic agents, therapeutic irradiation or genetic predisposition. Patients with the hereditary form of retinoblastoma (RB) appear genetically predisposed to the development of connective tissue tumours, particularly osteosarcoma. Therapeutic irradiation is an additional risk. Quantitation of the risk of SMN in RB patients may be influenced by selection biases and inappropriate analyses. Much of the biases in reported series arises from the limitations of single-centre studies. Loss of patients to follow-up, failure to adhere to properly defined criteria of SMN and to consider the risk of malignancy in the general population may have led to over-estimation of the risk of SMN in retinoblastoma patients.

Disease Susceptibility↗
PubMed1988

Dentate granule cells are essential for kainic acid-induced wet dog shakes but not for seizures.

The purpose of this study was to determine the role that dentate granule cells play in wet dog shakes (WDS), behavioral seizures, and hippocampal cell loss caused by systemic administration of kainic acid (KA). Rats were given bilateral injections of colchicine (COL) into the hippocampal formation to selectively lesion dentate granule cells. Two weeks later, they were injected subcutaneously with KA and were observed for WDS and seizures. Seizures were terminated with pentobarbital 2.5 hr after KA injection, and the rats were killed 48 hr later. The integrity of hippocampal cell populations and projections to the hippocampal formation from entorhinal cortex was assessed with radioimmunoassay and immunostaining for methionine-enkephalin (ME) and dynorphin (DYN) A, as well as with Timm and Nissl staining. Results indicate that COL injections eliminated KA-induced WDS, did not affect the latency to onset of seizures, and potentiated KA-induced cell loss in the CA3 region of hippocampus. COL lesions eliminated ME and DYN immunostaining of granule cells, but not ME immunostaining of entorhinal afferents to the dentate gyrus or Ammon's horn. These findings indicate that granule cells are an essential neuronal link in the expression of KA-induced WDS, but that seizures propagate along other pathways in the limbic system.

Animals↗
PubMed1987

New splinting materials.

Plaster of Paris (P.o.P.) bandage has been the pre-eminent external splinting material for over 150 years and from time to time synthetic alternatives have been tried. So far none has seriously challenged the dominance of P.o.P. as a primary or secondary material in the management of fractures. The recent introduction of Polyurethane coated fibreglass bandage appears to offer a more serious challenge than previous contenders. This technical note reviews bandage type splinting materials and explains some of the properties of the PU materials.

Bandages↗
PubMed1986

Red pigment in Bacillus megaterium spores.

Bacillus megaterium QM B1551 spores contained a unique red pigment in their membranes that was not found in other species. This red pigment, presumably a carotenoid, was synthesized about the time of dipicolinic acid synthesis during sporulation and was associated with the forespores. A yellow pigment was synthesized during sporulation in rich medium and was found in the mother cell compartment. Although the yellow pigment was also associated with spores, it could be removed by two different extraction procedures without impairing germination; it was absent when sporulation occurred in a minimal medium. Although the yellow pigment of the mother cell appeared to be dispensable, the red pigment may serve a more critical function, such as membrane stabilization.

Bacillus megaterium↗
PubMed1986

Enkephalin contained in dentate granule cells is important for kainic acid-induced wet dog shakes.

Kainic acid (KA) caused an initial decrease and a subsequent rebound in hippocampal enkephalin (ENK) in rats exhibiting wet dog shakes (WDS) without behavioral convulsions. Antibody to methionine-enkephalin but not dynorphin A(1-8) injected into lateral ventricles attenuated KA-induced WDS, as did naloxone. Granule-cell destroying injections of colchicine into ventral but not dorsal hippocampus caused a 60% reduction of hippocampal ENK and a complete elimination of KA-induced WDS. These studies suggest that release of granule cell ENK, which is 3 times more concentrated in ventral than dorsal hippocampus, plays an important role in KA-induced WDS.

Animals↗