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Biomedical subjects

D Lawrence

Publications and source records attributed to D Lawrence.

At least 19 recordsLinked to original sources
PubMed1979

Prophylaxis for postoperative deep-vein thrombosis. Synergistic effect of heparin and dihydroergotamine.

Randomized clinical trials in 300 patients undergoing major abdominal surgery or hip replacement arthroplasty were performed to investigate the efficacy of dihydroergotamine mesylate, heparin calcium, or a combination of dihydroergotamine with heparin in preventing postoperative deep-vein thrombosis (DVT). The diagnosis of DVT was established by an uptake test using fibrinogen labeled with iodine 125; in patients undergoing hip replacement, phlebography was also employed to confirm or refute the presence of isotopic thrombi. The data indicate that the combination of dihydroergotamine and heparin is more effective than heparin or dihydroergotamine alone in preventing DVT.

Abdomen↗
PubMed1979

Induction of ovulation in women with hyperprolactinemic amenorrhea using clomiphene and human chorionic gonadotropin of bromocriptine.

Clomiphene citrate (Clomid), when given alone, is generally considered ineffective in inducing ovulation in women with hyperprolactinemia. This study reports the treatment of 29 infertile women with hyperprolactinemic amenorrhea. Twenty-one patients (eighteen of whom had previously had no ovulation response to Clomid alone) were treated with a combined regimen of Clomid (100 to 200 mg/day for 5 days) and two injections of 5000 IU of human chorionic gonadotropin (HCG), the first 8 to 10 days after Clomid withdrawal and a second injection 1 week later. Basal body temperature charts, conception, and/or plasma progesterone measurements showed that 19 patients ovulated (90%). There were 17 pregnancies in 12 of 21 patients (57% pregnancy rate) with 15 single live births and two abortions. When bromocriptine (Parlodel) became available, a total of 22 patients (including 14 patients previously treated with Clomid/HCG, six of them successfully) with amenorrhea associated with hyperprolactinemia were treated with this drug with dosages varying from 2.5 mg to 15 mg/day. Ovulation was confirmed in 20 patients (90%). There were 17 pregnancies in 15 patients (68% pregnancy rate) with 15 single live births and two first-trimester abortions. In all, 21 of 29 patients (73%) achieved one or more pregnancies resulting in live births with one or both of the above treatments. It is concluded that a combined Clomid/HCG regimen can often be used as an effective alternative to bromocriptine therapy in the treatment of infertility associated with hyperprolactinemic amenorrhea.

Adult↗
PubMed1979

Cimetidine: effect on pancreatic and biliary function in man.

1 Pancreatic and biliary function were studied in eight patients taking oral cimetidine (1.6 g/day for 6 weeks) for endoscopically confirmed active peptic ulcer disease. 2 Postprandial jejunal tryptic activity and bile acid concentration were unchanged during cimetidine given for 1 and 6 weeks. 3 Postprandial gallbladder emptying was also unchanged. 4 Direct examination of postprandial upper jejunal aspirate for deconjugated bile acids was negative in all patients; but the more sensitive [14C]-glycocholate bile acid breath test showed a significant increase in breath 14CO2, indicating increased bacterial deconjugation of bile acids in the gastrointestinal tract.

Adult↗
PubMed1978

The origin of thrombi in the deep veins of the lower limb: a venographic study.

A series of 952 patients was examined by ascending venography; 812 with clinically diagnosed deep vein thrombosis (DVT) (group 1) and 140 with clinical features suggestive of pulmonary embolism (group 2). Thrombus was demonstrated in 401 (49.4 per cent) of group 1 and in 74 (53 per cent) of group 2 patients. A total of 535 limbs contained thrombus. In 493 (92 per cent) thrombus was present in the calf with either no further clot, or clot in continuity with that in more proximal veins. In the remaining 42 legs (8 per cent) thrombus either originated from multiple discontinuous sites in the legs and pelvis, or in proximal major veins without concomitant calf involvement. The clinical implications of these findings are discussed.

Femoral Vein↗
PubMed1978

Induction of ovulation with clomiphene and human chorionic gonadotrophin in women with hyperprolactinaemic amenorrhoea.

Seventeen women complaining of infertility (one with primary amenorrhoea, 14 with secondary amenorrhoea, and two with oligomenorrhoea) all had hyperprolactinaemia and were treated with clomiphene citrate and human chorionic gonadotrophin (HCG), and plasma oestradiol, FSH and LH levels were measured. Although adequate pre-ovulatory oestradiol levels were present, the surge of LH was absent until the injection of HCG after which all patients ovulated. There were 12 pregnancies in 9 patients resulting in 10 full-term livebirths, one premature livebirth and one continuing pregnancy. The relevance of these findings to the possible role of prolactin in amenorrhoea is discussed.

Adult↗
PubMed1977

Femoral vein thrombosis and total hip replacement.

Of 160 patients who underwent total hip replacement, 81 developed venographic evidence of thrombi in the operated leg. In 46 cases (57%) the thrombus originated from the femoral vein, and in 43 of these the exact site of origin was defined by venography. In 34 cases (74%) the thrombus arose from the wall of the femoral vein at the level of the lesser trochanter. This region was studied by intraoperative venography in eight patients undergoing total hip replacement, and in every case severe distortion of the common femoral vein was observed, producing almost total occlusion. We suggest that intraoperative damage to the femoral vein results from manipulation of the leg, and that this is one reason why the operation is followed by a high incidence of deep vein thrombosis in the upper femoral region.

Femoral Vein↗
PubMed1977

Blood-flow in incompetent perforating veins.

A new pulsed multichannel ultrasonic Doppler instrument was used to determine the relative blood-flow in the perforating veins of 16 patients with symptoms attributable to their leg venous systems. 9 patients had leg ulceration and 7 did not. 8 (89%) of the ulcer patients had sustained blood-flow from the deep to the superficial veins ("reverse") during calf muscle contraction, compared to 1 (14%) of the group without leg ulcers. This evidence supports the theory that postphlebitic leg ulceration is the result of retrograde flow of blood in incompetent calf perforating veins during walking.

Blood Circulation↗
PubMed1977

Surgery, venous thrombosis and anti-Xa.

Deep venous thrombosis is a common and unpredictable complication of surgery. In this study it is proposed that patients who develop this complication may be predicted by a low preoperative level of a naturally occurring inhibitor of coagulation, anti-Xa. Two groups of patients were investigated. Women taking the oral contraceptive pill had lower preoperative anti-Xa levels than their non-pill controls (P less than 0.01) and in addition had a significantly higher incidence of deep venous thrombosis (DVT) following emergency surgery (P less than 0.05). In 90 patients undergoing total hip replacement, the mean preoperative anti-Xa level of those patients who developed DVT was significantly lower than those who did not (P less than 0.001). Ninety-four per cent of patients with a preoperative anti-Xa level of less than 80 per cent developed DVT. The effect of low dose heparin on anti-Xa was studied. The results suggest a mechanism for the cause of postoperative thrombosis which also permits selection of individual patients who will develop this complication.

Adolescent↗
PubMed1977

An evaluation of the American Medical Association's Physician masterfile as a data source--one state's experience.

An evaluation of the American Medical Association's (AMA) Physician Masterfile is presented here on a state level. Both completeness and reliability of the AMA data were assessed for physicians licensed and living in Washington State. Comparison of the AMA data with state -LICENsure data indicated excellent agreement, with only a small proportion of license physicians "missing" from the AMA Masterfile. Their absence was due largely to differences in the manner in which the two systems updated their files. The reliability of the AMA data was checked by comparing it with similar, independently gathered survey data on birth date, birthplace, medical school, type of practice, specialty, board certifications, and employer. In general, despite some minor deficiencies, the AMA data were shown to be highly reliable.

American Medical Association↗
PubMed1977

Visual masking of targets displayed against two- and three-dimensional backgrounds.

Detection thresholds for targets displayed against two- and three-dimensional backgrounds were measured under backward masking and non-masking conditions. The results indicate that planar ring targets displayed against a two-dimensional ground are easier to mask than identical targets portrayed against a three-dimensional background. Also, the detectability of a planar ring target is enhanced when it is included within a three-dimensional rather than an identical but two-dimensional visual display. These results confirm and extend previous findings and suggest a processing asymmetry biased toward three-dimensional visual displays.

Adult↗
PubMed1976

Cimetidine in duodenal ulcer. Controlled trial.

As part of a double-blind controlled clinical trial of cimetidine (1.6 g daily) in patients with endoscopically proven duodenal ulcer, repeat endoscopy has been carried out in 24 patients after two and/or six weeks' treatment. At six weeks, 9 out of 11 patients on cimetidine and 3 out of 12 patients on placebo had healed (P less than 0.025). A separate open pilot trial in 23 patients has shown no difference in ulcer healing at six weeks between patients taking 0.8 and 1.6 g daily. A total of 32 different patients received cimetidine in the two trials, and ulcer healing was observed in 21 (66%) at six weeks. No patients showed evidence of bone-marrow toxicity. A small but significant rise in mean S.G.O.T., S.G.P.T., and serum-creatinine occurred in 13 patients on cimetidine 1.6 g daily, but not in 13 patients on 0.8 g daily.

Cimetidine↗
PubMed1975

Employment of MEDEX graduates and trainees. Five-year progress report for the United States.

The MEDEX approach to the training and deployment of physician extenders is described and contrasted with other physician-extender training models, and results of a survey of 277 MEDEX graduates and 207 trainees are presented. Practically all MEDEX graduates and trainees are employed in full-time practice and are working with fee-for-service family physicians in the rural areas of the United States, which suggests that the strategy used to place Medex practitioners into communities requiring additional health services has been successful.

Evaluation Studies as Topic↗