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Biomedical subjects

J Jenkins

Publications and source records attributed to J Jenkins.

At least 181 records · Page 10Linked to original sources
PubMed1984

Automatic tachycardia recognition.

A microcomputer algorithm for tachycardia identification, suitable for use in an implanted antitachycardia pacemaker, is described. The system employs an atrial and ventricular electrogram, detects a sustained fast rate in either chamber, and awakens the main program to perform detailed analysis of the tachycardia and its immediately preceding beats. The algorithm distinguishes atrial, ventricular, and AV nodal and re-entrant tachycardia from high rates due to sinus tachycardia. For testing of the program, we used a data base of twenty-two tape-recorded and documented arrhythmias provoked during electrophysiologic studies in which atrial and ventricular bipolar electrodes were in place; twenty-one were successfully detected. These included atrial fibrillation, atrial flutter, atrial tachycardia, AV nodal re-entrant tachycardia, AV re-entrant tachycardia using an accessory pathway, and ventricular tachycardia with and without ventriculo-atrial conduction.

Atrial Fibrillation↗
PubMed1984

Tachycardia detection in implantable antitachycardia devices.

We have developed a microcomputer algorithm for tachycardia identification suitable for use in an implanted antitachycardia pacemaker. The algorithm distinguishes atrial, ventricular, and AV reentrant tachycardia, while ignoring high rates due to sinus tachycardia. A new method whereby the pacemaker delivers an atrial extrastimulus has been developed for distinguishing paroxysmal 1:1 tachycardia from sinus tachycardia, and has undergone preliminary testing in the electrophysiology laboratory. Preliminary results indicate sinus tachycardia can be reliably distinguished from paroxysmal 1:1 tachycardia by a properly timed extrastimulus delivered to the right atrium.

Cardiac Pacing, Artificial↗
PubMed1984

Phase II trial of 5-FU administered Ip to patients with refractory ovarian cancer.

A phase II study of ip 5-FU was performed in 14 patients with ovarian cancer who were refractory to systemic chemotherapy including prior iv 5-FU in 12 of the patients. 5-FU was administered via a semipermanent Tenckhoff peritoneal dialysis catheter. The starting concentration of 5-FU in the dialysate was 4 mM. The patients received eight consecutive 2-L exchanges, each of 4-hour duration, for a total of 36 hours including time for instillation and drainage. Treatment courses were repeated every 2 weeks for six cycles or until disease progression occurred. A total of 69 cycles of ip 5-FU were administered to 14 patients. There was one complete response to therapy documented by second-look laparotomy. While the response rate was only 7%, in seven of eight (88%) patients with small volume disease (tumor masses less than 2.0 cm in diameter), there was no evidence for disease progression while receiving ip 5-FU therapy. In this phase II trial, the major toxic effect of ip 5-FU was abdominal pain. While there were no cases of documented bacterial peritonitis, all of the patients experienced some degree of abdominal discomfort while receiving therapy. Fifty percent of the patients had severe abdominal pain with at least one cycle of therapy. Other toxic effects included myelosuppression, mucositis, nausea and vomiting, and skin rash. The results of this study indicate that ip 5-FU should be further evaluated in patients with ovarian cancer who have a small volume of disease and who have not had prior therapy with 5-FU.

Abdomen↗
PubMed1984

Isolation and sequencing of a cDNA clone for a human HLA-ABC antigen.

A cDNA clone, pHLA-A, containing sequences specific for a human class I HLA antigen heavy chain, was isolated from a bank of clones made from partially purified HLA-ABC heavy chain mRNA from the human lymphoblastoid cell line Bristol 8 (HLA-A1, A2, B8, B16). The clone corresponded to sequence for the -COOH-terminal 117 amino acids of an HLA-ABC alpha-chain. It differed in at least 15 positions from the published HLA-B7 amino acid sequence but in only two residues when compared to the partial HLA-A2 protein sequence, and was identical to the HLA-A3 protein sequence derived from the nucleotide sequence of the gene. It also differed from some published human HLA-ABC sequences by the addition of three extra -COOH-terminal amino acids: cysteine-lysine-valine. The clone may correspond to either the HLA-A1 allele, for which independent sequence information is not available, or to HLA-A2, in which case there are possible explanations for the discrepancies. Comparison of the pHLA-A sequence with genomic HLA sequences suggests variations in splicing at the end of the protein coding region in some HLA-ABC heavy chain genes, and the use of alternative poly(A) addition sites.

Amino Acid Sequence↗
PubMed1984

Part-time higher professional training: an analysis of content.

Programmes for higher professional training (HPT) must be approved by the Joint Committee for Higher Training of Anaesthetists (JCHTA). The way in which these plans materialise into fact is however not necessarily analysed. A record has been kept of 2 years part-time work (equivalent to 1 year full-time for accreditation) and the content of this training is analysed. Altogether 1387 patients were treated and 38% of this work was supervised. Emergency cases totalled 4.2% and 200 regional anaesthetic blocks were performed. It is suggested that elements of training other than time spent in the operating theatre could be recognised in a more standardised fashion for the purpose of determining the necessary duration of HPT.

Anesthesia, Conduction↗
PubMed1984

Pharmacological evaluation of intravenous delivery of 5-bromodeoxyuridine to patients with brain tumors.

Previously, 5-bromodeoxyuridine (BrdUrd) has been shown to be an effective radiosensitizing agent in rapidly dividing cells. As part of a Phase I/II study to evaluate BrdUrd as a radiosensitizer in gliomas, the pharmacology was studied in eight patients. BrdUrd was infused using an i.v. route as a 12-hr constant infusion each day for as long as 14 days. BrdUrd steady-state arterial levels are described for three different infusional rates: 1.6 mumol/sq m/min (350 mg/sq m/12 hr) produced a steady-state arterial level of 0.7 microM; 3.2 mumol/sq m/min (700 mg/sq m/12 hr) resulted in 2.1 microM; 5.9 mumol/sq m/min (650 mg/sq m/6 hr) showed a level of 3.9 microM. Because of myelosuppression, the highest tolerable dose for this intermittent long-term infusional therapy with BrdUrd appears to be 700 mg/sq m/12 hr. Contrary to the nonlinear pharmacokinetics of thymidine, 5-fluorouracil, and 5-fluorodeoxyuridine described previously, BrdUrd shows linear behavior in the range studied. BrdUrd still has promise as a radiosensitizer for gliomas in humans, but an alternative means of safe delivery into the carotid artery is needed. Because of an estimated 11- to 16-fold-higher local concentration, use of the intraarterial route could deliver optimum levels of BrdUrd to the tumor with minimal systemic toxicity.

Brain Neoplasms↗
PubMed1983

Changing clinical picture of non-accidental injury to children.

The setting up of the South Glamorgan Area Review Committee and locally agreed procedures in 1974 has been associated with a considerable increase in observed moderately severe non-accidental injuries in children. The increase is in all age groups but is rising in older children. Most of the rise is likely to be due to increased community awareness. On the other hand, there has been a steady decrease in severe injuries, which may well be due to early recognition of minor or moderate injuries preventing the development of severe injuries.

Adolescent↗
PubMed1983

X-ray diffraction analysis of matrix porin, an integral membrane protein from Escherichia coli outer membranes.

An integral membrane protein forming channels across Escherichia coli outer membranes, porin, has been crystallized using a polyethylene glycol or salt-generated two-phase system. Monodispersity and homogeneity of protein-detergent complexes were found to be prerequisites for reproducible formation of crystals amenable to X-ray structural analysis. By varying pH, detergent and buffer type, large crystals of three different habits can be obtained, two of which are discussed in this paper. The tetragonal form (space group P4(2); unit cell dimensions, a = b = 155 A, c = 172 A) is suitable for X-ray analysis. Low temperature induces a change of the space group to P4(2)22, with a single trimer in the asymmetric unit. This crystal form diffracts to a resolution beyond 2.9 A. The hexagonal crystal form (space group P6(3)22; unit cell dimensions, a = b = 93 A, c = 220 A) is limited in resolution to 4.5 A, but reveals a packing arrangement very similar to that in two-dimensional membrane-like crystalline arrays.

Bacterial Proteins↗
PubMed1983

Race as an interpersonal variable in negative assertion.

Investigated assertive behavior among black male psychiatric patients under white vs. black interpersonal partner conditions. Twenty-four high and 24 low scorers in level of measured general assertiveness served as Ss (N = 48). Responses to familiar and unfamiliar interpersonal stimuli in two conditions, role-play, and in vivo, were videotaped and rated. Dependent variables in the role play condition were: (1) Request for new behavior; (2) compliance; (3) affect; and (4) overall assertiveness; and (1) expression of negative opinion; (2) compliance; and (3) overall assertiveness for the in vivo condition. Although MANOVA revealed no main effect for race, Ss in the unfamiliar condition were more assertive (p less than .05) than those in the familiar role play condition. Also, Ss' responses in role play were more assertive (p less than .05) in the unfamiliar-white prompter condition as compared to Ss' responses in the unfamiliar-black prompter condition. In the in vivo situation for overall assertiveness, responses were rated as more assertive in the white prompter condition. In addition, although Ss were more likely to express negative opinions in the black prompter condition, they were more likely to comply with an unreasonable request in the white prompter condition.

Adult↗
PubMed1983

Purification and partial amino acid sequence analysis of the cellular tumour antigen, p53, from mouse SV40-transformed cells.

The cellular tumour antigen p53 is implicated in the transformation process. To compare p53 from transformed cells and their normal counterparts in detail, and so to identify any structural differences that might alter p53 function, requires information on the primary structure of the protein. By making use of immunochemical techniques we have been able to purify nanomole amounts of p53. This was sufficient, using high sensitivity automated gas-phase sequencing techniques to determine the amino acid sequence of two tryptic peptides from p53. Their sequences agree completely with the predicted polypeptide sequence derived from a cloned cDNA for p53 mRNA and provide the first data on the amino acid sequence of p53. A combination of the high sensitivity amino acid sequencing procedures used here and cDNA sequence analysis should provide the complete amino acid sequence of p53.

Amino Acid Sequence↗
PubMed1983

Changes in body heat during transvesical prostatectomy. A comparison of general and epidural anaesthesia.

The superficial and deep body temperatures of 15 patients were measured before, during and for 6 hours after transvesical prostatectomy. The patients were divided randomly into two groups who received either a standard general anaesthetic or epidural analgesia. Total body heat and mean body temperature fell more rapidly in the epidural group, reaching statistical significance in the early postoperative period. Both groups showed a net heat gain 6 hours postoperatively. One patient in each group became hypothermic (core temperature less than 35 degrees C). Warming of both intravenous and bladder irrigation fluids to body temperature is recommended for patients receiving epidural or general anaesthesia.

Aged↗
PubMed1983

Goal-setting in terminal care: a method of recording treatment aims and priorities.

Although hospices are often said to provide a higher standard of care to terminally ill patients than conventional health care facilities, little empirical investigation has been conducted to test such statements. One aspect of the care process for which hospices are often praised is the attention paid to social and emotional problems concerning the patient, as well as more directly clinical matters. Often these goals are not explicitly stated. This paper investigates a method for systematically documenting the goals set by a multidisciplinary group of staff for the patients under their care. The study was conducted in a National Health Service (NHS) terminal cancer care unit, the staff of which were interested in setting clear, explicit objectives for their patients.

Documentation↗
PubMed1983

Topography of preemptying ventricular segments in patients with Wolff-Parkinson-White syndrome using scintigraphic phase mapping and esophageal pacing.

We analyzed the sequence of ventricular emptying using the phase image in 10 patients with accessory pathways and in 15 normal subjects. In normal subjects, the earliest emptying occurred in ventricular septal, apical and left basal segments. Eight patients had manifest preexcitation; the earliest emptying occurred ectopically in the right ventricle in one of these patients and in the left ventricle in five. The remaining two patients had normal phase maps. Two patients had concealed left-sided pathways. Their phase maps showed earliest emptying in left basal segments. Six of the 10 patients underwent electrophysiologic mapping. There was complete agreement between phase and electrophysiologic maps. Transesophageal atrial pacing increased preexcitation in one patient, normalized the ECG in another and precipitated narrow QRS tachycardia in four patients. Phase maps then showed enlargement, reduction and loss of the ectopic earliest emptying segments, respectively. We conclude that this technique in conjunction with pacing is successful in lateralizing accessory pathways.

Adolescent↗