Search PubMed⌕ Search

Biomedical subjects

J G Gray

Publications and source records attributed to J G Gray.

At least 37 records · Page 2Linked to original sources
PubMed1983

Use of gene fusions and protein-protein interaction in the isolation of a biologically active regulatory protein: the replication initiator protein of plasmid R6K.

The initiation of DNA replication of plasmid R6K is triggered by a 35-kilodalton initiator protein. The initiator protein had been elusive because of its lability and the lack of a convenient assay procedure to aid its purification. Using recombinant DNA techniques, we have fused the cistron of the initiator near its COOH-terminal end, in the correct reading frame, to the lacZ cistron of Escherichia coli at the ninth codon from the NH2 terminus. The fused cistron yielded a protein that was not only stable in vivo but also had dual activities: initiation of DNA replication in vivo and in vitro and hydrolysis of beta-galactoside. Using an affinity column that is specific for beta-galactosidase, we have demonstrated the rapid purification of the hybrid protein to near homogeneity. Exploiting the polymeric structure of the initiator, we have also isolated the nonfused form of the initiator protein, associated through subunit interaction with the beta-galactosidase-fused protein, which permits its purification by affinity chromatography. NH2-terminal amino acid sequence analysis of the heteropolymer has not only shown that the fused and nonfused initiators have the same sequence but also confirmed the protein sequence of the initiator as predicted from its nucleotide sequence. The techniques described here should be generally useful for the isolation of other proteins that are difficult to purify by conventional procedures.

Bacterial Proteins↗
PubMed1983

Pathogenesis of change in the upper respiratory tracts of turkeys experimentally infected with an Alcaligenes faecalis isolate.

The course of changes within the upper respiratory tracts of turkey poults experimentally infected with Alcaligenes faecalis was studied. The initial change observed (5 days post-inoculation) was colonization of the upper respiratory tract by the bacterium. Changes in the nasal turbinates and trachea were first apparent as a focal loss of cilia but subsequently developed into a general loss of cilia (11 days post-inoculation). Eventually, the entire ciliated epithelial layer in the cranial region of the trachea was lost (13 days post-inoculation). With the loss of cilia and ciliated cells, a highly viscous mucus was able to accumulate in the anterior one-half to two-thirds of the trachea. In addition, changes in the gross structure of the trachea (flaccid trachea) were observed in all poults inoculated with A. faecalis. There was an apparent gradation in the severity of these changes from severe in the cranial region of the trachea to mild in the region just anterior to the bronchial bifurcation. The observations resulting from A. faecalis infection indicated two major tracheal changes responsible for the chronic and sometimes severe nature of this disease. These changes included a loss of ciliary activity and a flaccid trachea which together resulted in the accumulation and stasis of mucus and tracheal collapse.

Alcaligenes↗
PubMed1981

The effect of topical povidone iodine on wound infection following abdominal surgery.

The effect of povidone iodine on wound sepsis following gastrointestinal surgery was studied in a trial involving 153 patients of whom 72 had their wounds sprayed with povidone iodine dry powder (Disadine DP) and 81 acted as a control group. The infection rate of 9.9 per cent in the patients treated with povidone iodine was significantly lower than that of 24.4 per cent in the control group (P less than 0.05). Bacterial contamination of the wound at the time of operation was shown to be of importance, being associated with a 52 per cent infection rate in the control group. However, spraying of contaminated wounds with povidone iodine reduced the infection rate to the significantly lower level of 11 per cent (P less than 0.05). We conclude that povidone iodine is a safe and effective means of reducing wound sepsis following gastrointestinal surgery.

Administration, Topical↗
PubMed1981

Cytotoxic activity of pathogenic Alcaligenes faecalis in turkey tracheal organ cultures.

Turkey tracheal organ cultures were used to study the virulence of Alcaligenes faecalis isolants that have been shown to be pathogenic for turkey poults. Viable infected and noninfected tracheal rings were examined by phase-contrast microscopy, and fixed stained sections were examined by light microscopy. Alcaligenes faecalis at concentrations of 10(8) and 10(9) colony-forming units/ml caused ciliostasis, hydropic degeneration (characterized by blebbing of the plasma membrane, cellular swelling, and cytoplasmic vacuolation), and eventual sloughing of the ciliated epithelium. Only ciliated epithelial cells appeared affected. For comparison, other bacterial isolants not pathogenic for turkeys were tried in this system. These bacterial isolants included 3 isolants of A faecalis from human beings and isolants of Klebsiella pneumoniae, Escherichia coli, and A faecalis from turkeys. Inoculation of each of these bacterial cultures onto tracheal organ cultures failed to produce the lesions described.

Alcaligenes↗
PubMed1979

Value of 1-alpha-hydroxy vitamin D3 in treatment of primary hyperparathyroidism before parathyroidectomy.

The postoperative course of six patients with primary hyperparathyroidism and obvious radiological evidence of bone disease pretreated with 1-alpha-hydroxy vitamin D3 (1 alpha HCC) was indistinguishable from that of six patients with a similar clinical and radiological picture who were not pretreated. 1alphaHCC may increase the hypercalcaemia in some cases and cannot be recommended for the routine preparation of such patients for surgery.

Adolescent↗
PubMed1976

Definitive emergency treatment of perforated duodenal ulcer.

A retrospective survey was made of all patients with a proved diagnosis of perforated duodenal ulcer admitted to a regional hospital during a recent six year period. The over-all mortality from this condition in the 192 patients was 11.4 per cent and mortality after operation, 6.3 per cent. One hundred and seventy-six patients were treated surgically. Seventy-seven patients underwent simple suture only with a mortality of 13 per cent and are compared with 99 patients treated by emergency vagotomy and pyloroplasty procedures with a 1 per cent mortality. Emergency definitive operations were performed without increased morbidity, mortality or hospital stay by junior surgeons with greatly improved long term results compared with simple suture. At the present time, emergency vagotomy and pyloroplasty procedures are the treatment of choice for a perforated duodenal ulcer.

Adolescent↗
PubMed1975

Compartments and cell flows within the mouse haemopoietic system. II. Estimated rates of interchange.

Part-body irradiated CBA mice were injected with CBA-T6 bone marrow. In this way a predominantly donor population was established in the femora while the marrow of the humeri remained largely (average 94%) of host origin. In animals examined cytologically up to 2 years later, no tendency was observed for the proportion of donor cells in the humeri to increase. Splenectomy had no effect on this. When femoral bone marrow from the experimental mice was injected into lethally (whole-body) irradiated recipients, cells originating from the primary host repopulated the lymph nodes to a disproportionate extent. Equilibration between the cell populations of femora and humeri occurred after re-exposure to 600 rad whole-body irradiation, but not after 100 rad or 350 rad; thus, regeneration of damaged bone marrow involved a significant contribution from extrinsic stem cells only after the highest dose of radiation. The data are compatible with an inflow of at most ten effective stem cells per humerus per day from the blood, and suggest a much lower figure. This means that few if any of the stem cells of peripheral blood enter the bone marrow and found haemopoietic clones. Evidence is adduced for the existence of a proliferating lymphoid sub-population in the bone marrow, contributing some 5-10% of the observed mitoses. The mitotic cells in the lymph nodes are replaced from marrow-derived progenitors at an estimated rate of 4-5%/day. The relevant data for the thymus are more variable, but suggest an average figure of 8-11%/day. Earlier data from mouse parabionts suggest a lower rate of inflow to the thymus.

Animals↗
PubMed1975

Acute reversible renal failure in patients with acute cholecystitis and cholangitis.

Although acute renal failure is a well recognized complication of several extra-hepatic biliary tract diseases especially biliary tract surgery in the presence of obstructive jaundice, there is little information concerning renal failure in acute cholecystitis. Renal function was assessed in 14 patients with acute cholecystitis and two with acute cholangitis. Six patients had no evidence of renal impairment, four had modest elevations of plasma urea and creatinine concentrations and six had acute reversible renal failure of whom three required peritoneal dialysis. Only one patient was hypovolaemic and in the remainder there was evidence that intravasular coagulation was responsible for the renal failure. It is suggested that bacteraemia was the initiating factor. The therapeutic implications of these findings are discussed.

Acute Disease↗
PubMedDate not supplied

Adenovirus respiratory infection in turkey poults.

A virus from turkey poults with respiratory signs was isolated in specific-pathogen-free embryonated chicken eggs and subsequently adapted to chicken embryo fibroblast and turkey kidney cell cultures, where round cell formation was observed. The cloned virus was ether-resistant and incorporated tridiated thymidine. Intra-nuclear icosahedral virus particles of 80 nm were detected. These physicochemical characteristics place this isolant into the adenovirus group of viruses. The disease was experimentally reproduced by intratracheal inoculation of one-day-old turkey poults. Snicking occurred in 100% of the birds and mortality reached 50%. CELO (Phelps strain) antiserum neutralized uncloned and cloned CUA-2 in chicken embryos and uncloned virus in chicken embryo fibroblast cell cultures. Quail bronchitis virus antiserum neutralized cloned CUA-2 in TK cells. Agar-gel precipitin lines of identity were formed using CELO antiserum and postinoculation sera from experimentally infected turkeys. Serologically, this virus should be classified as a type-1 adenovirus.

Adenoviridae↗