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Biomedical subjects

R Chapman

Publications and source records attributed to R Chapman.

At least 91 records · Page 5Linked to original sources
PubMed1993

Use of a retinoblastoma gene probe to investigate clonality in Richter's syndrome.

A 69-year-old woman presented with Rai stage 0 chronic lymphocytic leukemia. Ten years later she developed a diffuse centroblastic lymphoma involving the stomach. The surface membrane phenotype of the CLL cells was MD lambda while that of the large cell lymphoma (LCL) cells was MD kappa. The two populations had different heavy and kappa light chain rearrangements. Cytogenetic analysis of the CLL cells showed a deletion involving chromosome 13, band q14, but was unsuccessful in the LCL cells. However, use of a probe (p68 RS2.0) which recognizes a variable number tandem repeat sequence in the retinoblastoma gene, localized to chromosome 13q14, showed two alleles in the LCL cells but only one in the CLL cells. These data suggest that in this case of Richter's syndrome the CLL cells and the LCL cells are clonally distinct.

Aged↗
PubMed1993

Extracorporeal life support for adult cardiorespiratory failure.

BACKGROUND: Extracorporeal membrane oxygenation is routinely used for neonatal respiratory failure but is considered unsuccessful in adults based on old studies and old methods. We conducted a new phase 1 trial of modern extracorporeal life support (ECLS) in moribund adults with cardiorespiratory failure. METHODS: Criteria for initiation of ECLS were 90% mortality risk despite maximal conventional care, good potential for recovery, age < 60 years, and no contraindication to anticoagulation. Vascular access for ECLS was performed by operative or percutaneous cannulation. Continuous systemic heparinization was used, maintaining whole blood activated clotting time between 160 to 180 seconds. Blood components were transfused as necessary. Lung management included low rate and low pressure ventilation with an inspired oxygen fraction 0.5 or less. RESULTS: Forty patients were treated with ECLS, 30 with primary respiratory failure and 10 with primary cardiac failure. Twenty-two patients recovered lung or heart function, and 18 patients survived and were discharged from the hospital (14 with respiratory failure and four with cardiac failure, overall survival 45%). The major complication of ECLS was bleeding. CONCLUSIONS: With modern techniques, ECLS can be lifesaving in adult cardiorespiratory failure when conventional therapy has failed.

Adolescent↗
PubMed1993

The consistent 13q14 translocation breakpoint seen in chronic B-cell leukaemia (BCLL) involves deletion of the D13S25 locus which lies distal to the retinoblastoma predisposition gene.

Structural rearrangements involving chromosome 13 are frequently seen in B-cell chronic lymphocytic leukaemia. The presence of reciprocal translocations involving 13q14 in 10-15% of cases pinpoints the location of a gene important in leukaemogenesis. In order to characterise the exact location of the 13q14 breakpoint, somatic cell hybrids were constructed between mouse 3T3 cells and leukaemic cells from 5 patients with translocations involving chromosome 13. Hybrid pairs were isolated which carried either of the two derivative chromosomes carrying subsections of 13 and the position of the breakpoint investigated using a series of probes along the length of the chromosome. In all cases breakpoint region associated with rhabdomyosarcoma tumours and proximal to the D13S31 locus which lies in 13q14.3. In three translocations the RB1 gene was deleted as a result of the translocation but in at least one other case the BCLL breakpoint did not involve the RB1 gene, which consistently cosegregated in hybrids carrying other proximal markers. The D13S25 probe, which lies between RB1 and D13S31, however, was deleted in the translocation retaining RB1. It appears therefore that deletion of a gene(s) in this 2Mbp region is a critical event in some cases of BCLL tumorigenesis.

Animals↗
PubMed1992

The outcome of unexplained dyspepsia. A questionnaire follow-up study of patients after endoscopy.

Ninety-three consecutive patients referred to a gastroenterology unit with unexplained dyspeptic symptoms were sent a postal questionnaire 6-12 months after endoscopy. It inquired into their current physical symptoms and subjective improvement since investigation, satisfaction with treatment, past history and current psychological well-being. A comparison group of 47 patients with peptic disease were similarly surveyed. Those with unexplained dyspepsia reported more current physical symptoms, more dissatisfaction with their treatment and less subjective improvement than those with peptic disease. The two groups were similar in terms of psychological distress but previous consultation for abdominal and other somatic complaints were more common in those with unexplained dyspepsia. The implications for management of dyspeptic patients are discussed.

Adult↗
PubMed1991

It's better by day.

Day surgery has had a slow record f growth in the UK, despite the benefits it offers. Robert Chapman explains the advantages of planning a dedicated unit.

Facility Design and Construction↗
PubMed1991

Why patients consult and what happens when they do.

OBJECTIVE: To study patients' perceptions of why they consulted the doctor, how ill they thought they were, and what happened in the consultation. To compare patients' perceptions before and after the consultation and to compare these perceptions with those of the doctor. DESIGN: Patients filled in a questionnaire before and after the consultation. The doctor filled a questionnaire in after the consultation. SETTING: Three general practices in Bedfordshire and one in Hertfordshire. PATIENTS: 500 consecutive patients consulting in each practice. MAIN OUTCOME MEASURES: Changes in patients' perceptions and differences between the perceptions of patients and doctors. RESULTS: Doctors perceived patients to be less ill than the patients themselves did. Patients from social classes IV and V and children perceived themselves to be more ill than the average. Patients perceived themselves to be less ill after the consultation. A third of patients attended because doctors had told them to, and a quarter of patients had already tried to treat their problem themselves when they attended the consultation. Doctors' perceptions of the consultation emphasised listening, supporting, and giving advice. Patients' perceptions emphasised prescribing, reassuring, and referring to a consultant. Doctors perceived that they listened, examined, and gave advice less to social classes IV and V than to social classes I, II, and III and gave explanations more often to men than to women. Patients perceived external factors rather than lifestyle factors as being more important in causing their problems. CONCLUSION: Doctors' perceptions of patients' problems differed from those of patients expressed both before and after their consultation. Doctors' and patients' perceptions also differed about the consultation itself. The consultation reassured some patients.

Attitude to Health↗
PubMed1991

Phase III comparison of doxorubicin and dacarbazine given by bolus versus infusion in patients with soft-tissue sarcomas: a Southwest Oncology Group study.

Disseminated soft-tissue sarcomas are a group of uncommon malignancies generally treated in a uniform manner. This study questioned the impact of schedule on response rate and toxicity in patients with metastatic soft-tissue sarcoma treated with the two-drug combination doxorubicin and dacarbazine. Patients were randomly assigned to receive either bolus therapy with doxorubicin at a dose of 60 mg/m2 and dacarbazine at a dose of 750 mg/m2 intravenously on day 1 (118 patients) or infusional therapy with doxorubicin at 60 mg/m2 and dacarbazine at 750 mg/m2 delivered by continuous intravenous infusion for 96 hours on days 1-4 (122 patients). Chemotherapy was to be repeated every 3 weeks. A unique feature of this cooperative group protocol was a provision for surgical resection of residual disease in patients with a partial response or with stable disease following chemotherapy. Similar overall response rates (17% in both treatment arms) and complete response rates (5% in both treatment arms) were observed. For patients receiving bolus therapy, the median response duration was 19.6 months for those in complete remission and 6.6 months for those in partial remission. For patients receiving infusional therapy, the median response duration was 12.6 months for those in complete remission and 9.3 months for those in partial remission. Examination of dose intensity received when combining treatment arms revealed a weak doxorubicin dose-response relationship. There was no difference in median survival times between the two treatment arms (bolus therapy, 10.6 months; infusional therapy, 10.5 months; logrank P = .97). Analysis of toxic effects favored infusional therapy. Significant reductions in cardiac toxicity (all events, P = .04; clinical events, P = .01) and nausea and emesis (P = .04) were seen in infusional therapy. Of 47 patients eligible for cytoreductive surgery following chemotherapy, 12 received surgery, and of those 12, eight were rendered disease free. The use of a 96-hour continuous intravenous infusion of doxorubicin-dacarbazine was comparable therapeutically with bolus dosing of these two agents and was better tolerated by the patients.

Adolescent↗
PubMed1991

Complement activation by dental implants.

Activation of complement leads to the generation of C3a and C5a inflammatory peptides. C5a is a potent chemotactic factor, stimulating the secretion of proteolytic enzymes by neutrophils and osteoclast activating factor/Interleukin-1 by monocytes. In vitro generation of C3a and C5a was measured by radioimmunoassay techniques. The results showed significant complement activation by all implants tested when compared to the control serum incubation. It is concluded that all of the implants studied activated the complement system and are not physiologically inert. Complement activation, therefore, may contribute either positively to healing or negatively to a poor outcome in osseoadaptation initially or over time.

Complement Activation↗
PubMed1990

Asherman's syndrome: a review of the literature, and a husband and wife's 20-year world-wide experience.

Asherman's syndrome is reviewed, and 27 cases treated by us in Iran, England, New Zealand and Australia over a 20-year period are analysed. Aetiological factors and treatment are discussed. In view of the high incidence of complications in subsequent pregnancies, the need for prevention is stressed. Although more common in some countries, it is, nevertheless, of world-wide distribution and, unless looked for, will be missed.

Amenorrhea↗
PubMed1990

Pulmonary function, airway responsiveness, and respiratory symptoms in asthmatics following exercise in NO2.

Two experiments were conducted to determine respiratory responses of persons with asthma performing intermittent moderate exercise while exposed to low concentrations of NO2. In the first, preliminary experiment, 13 male subjects, aged 19-35, with mild asthma were exposed on separate days in a chamber (natural breathing, 20 degrees C, 40% RH) to 0.30 ppm NO2 and to a control or "clean air" exposure (0.0 ppm NO2). Exposure included three 10-min periods of moderate treadmill exercise (VE = 44.5 liter/min), each followed by symptom measurement and pulmonary function testing. The average decrease in FEV1 following the initial 10 min exercise in 0.30 ppm was 11% which was significantly greater (p less than 0.05) than that observed in clean air (7%). Differences in FVC and SRaw were not significantly different at this time. Slight cough and dry mouth and throat were apparent only after the first exercise in NO2. After the second and third exercises, decreases in FEV1 and FVC and increases in SRaw were significantly greater in 0.30 than in 0.0 ppm NO2. Individual subject responses were variable. These results suggested that some asthmatics who perform moderate exercise while exposed to 0.30 ppm NO2 may experience bronchoconstriction and reduction in spirometric performance. Because of these preliminary findings, a more comprehensive, concentration-response experiment was conducted. Twenty-one male volunteers with mild asthma were exposed for 75 min with natural breathing to 0.0, 0.15, 0.30, and 0.60 ppm NO2. Exposure included three 10-min periods of moderate treadmill exercise (VE = 43 liter/min), each exercise followed by symptoms measurement and pulmonary function testing. In addition, airway responsiveness was measured two hr after each exposure by methacholine bronchial challenge testing. In the control exposures (0.0 ppm NO2), the exercise alone caused substantial decrements in pulmonary function. These decrements (as measured by decreases in FEV1 and FVC, and increases in SRaw) were not increased relative to the control exposure after any exercise session in any concentration of NO2. Furthermore, there was no overall group-averaged indication of a concentration-related effect of the NO2 on pulmonary function. Likewise, symptoms reported after NO2 exposure were not significantly different from those reported in clean air. Group-averaged airway responsiveness after exercise in NO2 was also not different from responsiveness after exercise in clean air. For only two subjects was there any indication of a concentration-related increase in airway responsiveness due to exposure to NO2.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1990

Evaluation of menogaril in renal cell carcinoma. A Southwest Oncology Group phase II study (8504).

The Southwest Oncology Group (SWOG) studied the response rate and toxicity of menogaril (200 mg/m2 i.v. q 28 days) in patients with advanced metastatic renal cell carcinoma. During the early stage of the trial two partial responses were seen in the first 20 treated patients, and an additional 36 evaluable patients were studied. Three of 56 (5%) evaluable patients achieved partial responses. Significant white cell toxicity was observed. Mild or moderate degrees of thrombocytopenia, gastrointestinal side effects, alopecia and phlebitis occurred. No cardiac toxicity was noted. The low response rate suggests that menogaril in this dose schedule has no role in the treatment of patients with advanced metastatic renal cancer.

Antineoplastic Agents↗
PubMed1990

Chief complaint of fatigue: a prospective study.

The Dartmouth COOP Project, a primary care research network, conducted a prospective study of patients presenting to 28 primary care practices with a chief complaint of fatigue. Data were gathered on fatigue status, associated systems, health status, and origin of fatigue. Fatigue patients were demographically similar to nonfatigue patients but had significantly worse physical and mental health at study intake. Sixty-three percent of physicians and 52% of patients rated fatigue origin as primarily physical (gamma = 0.48, P less than .05), but in 41% of cases, physicians indicated there was substantial interaction between physical and psychological factors. Only two factors--depression and anxiety--separated fatigue of physical origin from fatigue of psychological origin. Clinicians must thoughtfully evaluate fatigue's often multiple causes and communicate their understanding of those causes to the patient to gain support for a reasonable treatment regimen.

Adult↗
PubMed1990

Multidimensional work sampling to quantify a pharmacokinetics resident's duties.

A multidimensional work-sampling technique was used to quantify a pharmacokinetics resident's duties. Four dimensions were measured: activity, contact, function, and location. A code list of 47 variables was developed to encompass all activities of the resident being observed. A combination of self-reporting and observer reporting was used to test the veracity of the resident's report and to determine whether differences in reporting occurred. Observation was done 20 times a day over a five-week period (24 working days). Random time periods separated the observation points. The observer and the resident recorded 260 and 220 observations, respectively, for a total of 480. The overall reliability measure was 78%, indicating good interobserver agreement. The resident spent about 36% of his time doing work related to pharmacokinetics consultations and 23% of his time attending meetings. He spent a large proportion of time (48.5%) working alone. Much of his remaining time was spent with the Pharm.D. students and the preceptors. Multidimensional work sampling based on a combination of self-reporting and observer reporting is a useful tool for quantifying the work practices of pharmacokinetics residents.

Education, Pharmacy, Graduate↗