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Biomedical subjects

G Gray

Publications and source records attributed to G Gray.

At least 91 records · Page 5Linked to original sources
PubMed1988

Hydromorphone levels and pain control in patients with severe chronic pain.

To better understand the use of narcotic analgesics, the hydromorphone concentration was measured in serum samples from 43 patients with chronic severe pain who were receiving this drug. At the time of blood sampling, pain intensity, mood, and cognitive performance were assessed. There was large individual variation in the dose-drug level relationship. Seven patients with bone or soft tissue pain and drug levels of greater than or equal to 4 ng/ml had good pain control, whereas 10 did not. None of 15 patients with levels less than 4 ng/ml had pain control, despite drug doses similar to those given patients with higher levels. Thus 60% of the patients without control of their pain had hydromorphone levels below the lowest level that produced pain control. No patient with pain from nerve infiltration or compression had good pain control, irrespective of the drug level or dose. Poor mood correlated with high pain intensity and low drug level. Impaired cognitive performance was not related to drug level. Knowing that there is a low concentration of narcotic in the blood of a patient with chronic severe pain who is receiving high drug doses and who shows lack of both efficacy and side effects may reassure health care professionals that further narcotic dosage escalation is appropriate.

Adult↗
PubMed1988

A new intraoperative approach for endocardial mapping of ventricular tachycardia.

Results of operation for control of ventricular tachycardia have improved since endocardial mapping techniques have been developed that allow a directed approach to the problem. In some patients, a limitation of established techniques has been difficulty in initiating the arrhythmia after a ventriculotomy has been made to allow introduction of endocardial recording electrodes. This paper describes a transatrial approach for endocardial mapping with a balloon array of 112 electrodes, which has been used intraoperatively in 15 patients. Surgical success in this group has been compared to that obtained in a similar group of patients in whom standard techniques of intraoperative mapping were used. With our new balloon technique we have been able to easily induce and map multiple episodes of ventricular tachycardia in all cases. On the basis of detailed endocardial maps, the locations of earliest activation and possible reentry loops have been identified and ablated with either endocardial excision or application of the cryoprobe. When indicated, concomitant procedures including aneurysm resection (9/15) and bypass grafting (14/15) have been performed. Hospital mortality in this group was 20%. None of the deaths have been related to recurrent ventricular tachycardia or complications of the mapping technique. Postoperative electrophysiologic studies performed at 2 weeks have been normal in 11 of 12 or 92% of patients. To date (mean follow-up 12 +/- 6 months) there has been no clinical recurrence or evidence of ventricular tachycardia by Holter monitoring in these patients. We conclude that the transatrial balloon approach to endocardial mapping facilitates intraoperative induction of ventricular tachycardia, allows complete mapping during multiple runs of the arrhythmia without prolonging cardiopulmonary bypass time, and improves results of operation using standard ablation techniques.

Cardiac Pacing, Artificial↗
PubMed1987

High-level secretion of human growth hormone by Escherichia coli.

A gene encoding the mature form of human growth hormone (hGH) was fused to the secretion signal coding sequence of the Escherichia coli heat-stable enterotoxin II (STII). This hybrid gene was preceded by two Shine-Dalgarno sequences derived from the trp and STII-coding genes and was expressed in E. coli under the transcriptional control of the E. coli alkaline phosphatase (phoA) promoter. In low-phosphate growth media, cells synthesized about 15 to 25 micrograms of hGH/ml/1 A550 unit of cells. This represents 6 to 10% of total cellular protein. The majority of the hGH produced (more than 90%) was processed precisely and secreted into the periplasmic space. These results demonstrate that E. coli cells are able to synthesize and secrete high levels of this human protein using a prokaryotic signal sequence.

Chorionic Gonadotropin↗
PubMed1987

Reversible, narcotic-associated mental status impairment in patients with metastatic cancer.

Pain and mental status were assessed in a series of 35 consecutive hospitalized patients with metastatic cancer receiving narcotics for pain that was difficult to control. Forty-five episodes of mental status impairment were detected in 27 of these patients. Fifteen patients had dose-related oversedation or organic brain syndrome. In only 4 could the narcotic dose be decreased without exacerbating the pain. Eleven patients had mental status impairment associated with factors other than the narcotic dose. These factors were: concurrent CNS-depressant drugs, presence of fever or infection, or changing from parental to average oral equianalgesic dose of narcotic. When these factors were corrected, mental function improved and remained stable despite resumption of the previous narcotic dose. Delirium occurred more frequently in patients over 65, while oversedation without delirium was more frequent in the younger group. For some patients with advanced metastatic cancer, pain relief and intact mental status cannot coexist. For others, correction of factors other than narcotics which can impair function can often lead to improved mental status without decreasing narcotic dose or decreasing the degree of pain control.

Adult↗
PubMed1987

Comparison of left ventricular assist and intra-aortic balloon counterpulsation during early reperfusion after ischemic arrest of the heart.

In most centers, intra-aortic balloon counterpulsation and inotrope infusion are used for patients who require support to be weaned from cardiopulmonary bypass at the end of a cardiac surgical procedure. Where available, early institution of a left ventricular assist device is an alternative with possible advantages. In a canine model of left ventricular failure caused by 45 minutes of normothermic ischemic arrest, these two methods of support were instituted after an initial 30-minute reperfusion period. Both methods provided adequate support of the circulation (cardiac output greater than 2 L/min and mean arterial pressure greater than 50 mm Hg). After only 3 hours, however, significant differences were seen between the two groups. When the hearts were examined histologically, dogs in the group with intra-aortic balloon counterpulsation and inotrope infusion had significantly more necrosis than those in the group with a left ventricular assist device, 7.7% +/- 5.0% (mean +/- standard deviation) versus 2.0% +/- 1.3%. Decreases in compliance and systolic function were significantly greater in the group with intra-aortic balloon counterpulsation and inotrope infusion when compared with those supported with a left ventricular assist device. These findings suggest that even when support with intra-aortic balloon counterpulsation and inotrope infusion resulted in satisfactory hemodynamics, early institution of a left ventricular assist device was significantly more effective in preserving myocardial structure and function.

Animals↗
PubMed1986

Noncirrhotic portal fibrosis after Wilms' tumor therapy.

A 9-yr-old girl developed massive hemorrhage from esophageal varices 2 yr after combined modality therapy for Wilms' tumor. Evaluation showed a patent extrahepatic portal venous system and an elevated splenic pulp pressure. In contrast to previous reports of hepatopathy after irradiation injury, histologic sections of the liver did not demonstrate occlusion of the central veins, but rather a diffuse obliteration of intrahepatic portal venous radicles. This pattern of noncirrhotic portal fibrosis has not been described following antitumor therapy.

Child↗
PubMed1986

CT of fibrous tissues and tumors with sonographic correlation.

Fibrous tissues and tumors may appear hyperdense relative to muscles and solid viscera on CT both before and after IV contrast injection. In addition, fibrous tissues generally have a homogeneously hypoechoic sonographic appearance. The diagnostic value of these criteria is illustrated in a group of 21 fibrous tissue abnormalities that includes retroperitoneal, mediastinal, and perigraft fibrosis, sclerosing pseudotumor of the orbit, generalized fibromatosis, desmoids, malignant fibrous histiocytoma, and normal tendons and ligaments. It is concluded that while hyperdensity on CT and echopenia on sonography are not pathognomonic of fibrous tissue, they occur with sufficient frequency that their presence raises the possibility of a fibrous lesion.

Connective Tissue↗
PubMed1985

Analysis of solid-state Carbon-13 NMR spectra of polymorphs (benoxaprofen and nabilone) and pseudopolymorphs (cefazolin).

The solid-state 13C-NMR spectra of the polymorphs of benoxaprofen, nabilone, and cefazolin are reported using the cross-polarization/magic-angle spinning (CP/MAS) technique. In general, the spectra of the different crystal forms are different. In favorable cases the spectra of the drug in a pharmaceutical granulation can be discerned. These results provide a preliminary indication that solid-state NMR spectroscopy is a useful technique for the investigation of drug polymorphs and drugs in their dosage forms.

Anti-Inflammatory Agents↗
PubMed1985

Reading retardation and antisocial behaviour: a follow-up into employment.

The implications of the frequent overlap between reading and behavioural disorders in childhood are explored using follow-up findings on the secondary school progress and early work histories of four groups of boys, with an without reading retardation, and with and without behavioural disturbance. While the prognosis for the majority of the retarded readers appeared poor, certain particular features-high rates of early school leaving, unstable work records and especially depressed skill levels-characterized those with associated behavioural problems. The importance of separating out the effects of additional associated disorders and disadvantages in assessing the long-term prognosis for children with learning problems is discussed.

Absenteeism↗
PubMed1984

Human apolipoprotein A-I and C-III genes reside in the p11----q13 region of chromosome 11.

Apolipoprotein (apo) A-I is a major protein of high density lipoproteins (HDL). The gene for apoA-I has been localized to the p11 leads to q13 region of chromosome 11 by filter hybridization analysis of mouse-human hybrid cell cDNAs containing chromosome 11 translocations utilizing a cloned human apoA-I cDNA probe. The known linkage of apoA-I and apoC-III also permitted the simultaneous assignment of the apoC-III gene to the same region on chromosome 11. Comparison with previously established gene linkages on the mouse and human genome suggests that apoA-I + apoC-III may be linked to the esterase A4 and uroporphyrinogen synthase genes which are present on the long arm of human chromosome 11. The localization of the apoA-I + apoC-III genes in the p11----q13 region of chromosome 11 represents a definitive chromosomal assignment of a human apolipoprotein gene, and will now enable more detailed analysis of the geneomic organization and linkages of the apolipoprotein genes.

Animals↗
PubMed1984

Evolutionary relationships among genes for antibiotic resistance.

The genes that determine resistance to antibiotics are commonly found encoded by extrachromosomal elements in bacteria. These were described first in Enterobacteriaceae and subsequently in a variety of other genera; their spread is associated with the increased use of antibiotics in human and animal medicine. Antibiotic-resistance genes that determine the production of enzymes which modify (detoxify) the antibiotics have been detected in antibiotic-producing organisms. It has been suggested that the producing strains provided the source of antibiotic-resistance genes that were then 'picked-up' by recombination. Recent studies of the nucleotide sequence of certain antibiotic-resistance genes indicate regions of strong homology in the encoded proteins. The implications of these similarities are discussed.

Amino Acid Sequence↗
PubMed1984

Synthesis of bovine growth hormone by Streptomyces lividans.

Streptomyces lividans 66 was transformed with a plasmid containing the regulatory region of the Streptomyces fradiae aph gene and a structural gene that specifies bovine growth hormone (bGH). When grown in liquid culture the transformant contained a protein identical to authentic bGH, as judged by radioimmunoassay and immuno-blotting (Western analysis). The bGH was present in cells that had been in culture for up to four weeks but was not found in the medium. The strategy employed should be generally applicable to the expression of foreign genes in actinomycetes.

Animals↗