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Biomedical subjects

J L Dawson

Publications and source records attributed to J L Dawson.

At least 37 records · Page 2Linked to original sources
PubMed1981

Long term follow-up of interposition mesocaval shunting in portal hypertension.

The long term results of 28 interposition mesocaval shunts performed between 1971 and 1975 are analysed over a follow-up period of 5-9 years. There were 6 emergency operations and 22 elective operations, with an overall operative mortality of 14.3 per cent and a 5-year survival for the complete series of 31.5 per cent (class A patients 55.5 per cent, class B 33 per cent and class C 0 per cent). Shunt patency at 7 months was 95 per cent but by 5 years this had fallen to 53 per cent. Further variceal bleeding occurred in 6 patients (31.5 per cent) in 4 of whom shunt occlusion was confirmed.

Adult↗
PubMed1981

Newer techniques in the diagnosis and treatment of proximal bile duct carcinoma--an analysis of 41 consecutive patients.

The clinical course of 41 consecutive patients with primary bile duct carcinoma at or near the liver hilum was analysed to determine whether the outcome was improved by newer techniques of diagnosis and treatment. The age range was wide, with one third under 50 years. The only aetiological factor identified was long-standing ulcerative colitis (present in 9.8 per cent of patients). In one third of patients initial symptoms were misleading. The tumour had been missed in 11 (61 per cent) of 18 patients undergoing an exploratory laparotomy at other hospitals, despite operative cholangiography. None had pre-operative percutaneous cholangiography which was shown to be the best investigatory technique, giving the correct diagnosis in all cases in whom it was performed. Greyscale ultrasonography was useful and endoscopic retrograde cholangiography less so. Median survival in those treated by surgical T- or U-tube drainage (21 patients) or bypass (three) was nine months from diagnosis, as opposed to three months in the 36.5 per cent of patients in whom biliary drainage was not obtained. Radiotherapy, including insertion of a radioactive iridium wire through the tumour via a T- or U-tube, or percutaneously, was performed in nine patients and improved the duration of survival compared with tube drainage alone. The new percutaneous techniques offer a useful alternative to surgery for palliative drainage and radiotherapy.

Adult↗
PubMed1980

Prospective controlled trial of injection sclerotherapy in patient with cirrhosis and recent variceal haemorrhage.

64 patients with cirrhosis and recent variceal haemorrhage were studied in a prospective randomised trial of injection sclerotherapy by means of a flexible oesophageal sheath. 12 (33%) of the 36 patients in the sclerotherapy group, suffered further bleeds from varices compared with 19 (68%) of the 28 patients receiving standard medical treatment. The risk of bleeding per patient-month of follow up decreased more than threefold with sclerotherapy and the number of patients rebleeding after 2, 6, and 12 months was significantly reduced (p < 0.05). 1-year survival without further bleeding improved significantly with sclerotherapy (46% compared with 6%, p < 0.02), although the difference in overall survival assessed by cumulative life-table analysis was not statistically significant. The main complication of the technique was the development of oesophageal ulcers in some patients.

Esophageal Diseases↗
PubMed1979

Fibreoptic injection of oesophageal varices.

A new technique for injecting sclerosant into oesophageal varices uses a flexible gastroscope. Once the gastroscope has been inserted a flexible tube with a window cut into its distal end is pushed down over the gastroscope until a varix protrudes through the window. The varix can then be injected with a needle passed down the biopsy channel of the gastroscope. Once the varices have all been injected in this way the tube is advanced to compress the injection sites and so help control bleeding. This method, using a flexible gastroscope, has proved easier and safer than the traditional method using a rigid gastroscope.

Esophageal and Gastric Varices↗
PubMed1978

The treatment of haemobilia.

This paper describes 4 cases of haemobilia. The use of hepatic arterial ligation in its management is discussed. Attention is drawn to the raised serum amylase level in the 2 patients in whom it was measured.

Adult↗
PubMed1978

Obstructive jaundice and portal vein calcification.

Two patients with extrahepatic portal vein obstruction are described in whom calcification within the thrombus was identified during investigation for obstructive jaundice. Evidence from percutaneous cholangiography in one, and endoscopic cannulation of the common bile duct in the other, supported the view that the common bile duct was being partially compressed by the calcified cavernoma.

Adult↗
PubMed1978

Wound closure with Dexon (polyglycolic acid) mass suture.

A series of 814 consectuvie laparotomy incisions at three hospitals were closed with No 2 Dexon (polyglycolic acid) sutures using the 'near and far' technique. The incidence of wound dehiscence was 0.5%, of sinus formation 1%, and of incisional hernia 2.2% at 6 months and 6% at 3 years.

Humans↗
PubMed1977

An anthropological perspective on the evolution and lateralization of the brain.

The purpose of this paper is to review the anthropological evidence relating to the cultural determinants of the right-hand first postaulted by Hertz in his classic study. Also a genetic/cultural conformity model of handedness is presented that postulates that the incidence of handedness in a society is held to result both from the genetic expression of handedness interacting with cultural pressures towards conformity. The evolutionary basis for the hemispheric functional organization into cognitive and perceptual hemispheric functions is discussed in terms of "right-handed dominant homozygotes, DD," "heterozygotes, DR," mixed-handers, and "left-handed recessive homozygotes, RR." The cross-cultural distribution of handedness provides support for this model since the more conforming agriculturalists as measured by the Asch Test have a significantly lower incidence of left-handedness (0.59%, 1.5% and 3.4%), while the more permissively socialized Eskimo and Arunta hunters, who are seen to be more independent on the Asch Test, have 11.3% and 10.5% left-handers, respectively. Also, due to the greater pressures for females to conform in agricultural societies, the incidence of female left-handedness in agricultural societies is 0% out of 330 female Ss, with 3.8%, 0.79%, and 2.5% in agricultural males, as contrasted with the Eskimo hunters who have 12.5% left-handed males and 10.3% left-handed females, showing no significant sex difference. A further Hong Kong-English study also supports the genetic/cultural conformity model with a significantly lower incidence of Hong Kong Chinese left-handers (RR: male = 2.7%, and female = 4.2%). The next section, concerned with the neonatal sex-hormone differentiation and lateralization processes, provides a neuropsychologic theory relating to spatial and linguistic skills that is relevant to the following section, which deals with relationships between laterality and cognitive style. The results are also presented for the Alaskan Eskimo in relation to hand, eye, auditory dominance and cognitive style. The analysis of Eskimo fixed-versus mixed-laterality data also confirms, as predicted, that both within and across a modality (e.g., right hand/right eye/right ear) fixed right-dominance Eskimo Ss are more field-independent than mixed-dominance Ss, while the fixed left-dominance Ss are the most field-dependent and have lower spatial skills. The discussion section reviews the papers relating to the genetic/conformity model of handedness, as well as laterality and cognitive style. The evolutionary adaptive significance of sex differences in gonadal differentiation and lateralization of the brain on spatial and linguistic skills are also reviewed. The conclusions are concerned with the implications for biosocial theory and the rapidly changing incidence of left-handedness due to accompanying changes in cultural pressures both within and across cultures.

Adult↗
PubMed1976

Focal nodular hyperplasia of the liver: a rational approach to treatment.

Focal nodular hyperplasia of the liver in a 3 year old child has been successfully treated by ligation of the hepatic artery branches supplying the lesion. The prominence of the abnormal vasculature in the lesion and its possible aetiological involvement is stressed. Because of the risks of partial hepatectomy, hepatic artery ligation is suggested as the treatment of choice for focal nodular hyperplasia.

Child, Preschool↗
PubMed1975

Developmental effects of neonatal sex hormones on spatial and activity skills in the white rat.

The purpose of this experiment is to extend these experiments by using varying neonatal hormonal differentiation processes and to examine the effects of these different methods of neonatal feminization on changes in spatial and activity skills. The experiment involved three neonatally feminized groups of male rats: 'castration alone', 'estrogen alone', and 'estrogen injected castrates' together with one female sample, 'testosterone injected castrates', while treated and untreated male and female controls were also used. The data provide partial support for the major hypotheses that neonatal gonadectomy and opposite sex hormones administered to male and female castrated rats (together and independently for males) would reverse the normal sex-associated abilities of the white rate (higher male spatial learning and higher female activity). However, the feminization effect for the male 'estrogen alone' and 'castration alone' experimental groups was much greater than for the male estrogen injected castrates. The masculinized females, testosterone injected castrates, also had higher spatial learning and lower activity levels, while the feminized male's spatial and activity skills were also reversed. This confirmed in part the extent to which neonatal gonadal sex hormones are effective at critical periods of development in programming the brain in terms of sex-associated spatial and activity skills. Adult hormonal replacement therapy was also administered at 12 months and supported the hypothesis that sex hormones in adults would be mainly activational and have less marked effects than the significant directional changes obtained by these neonatal sex hormones and castration techniques.

Age Factors↗
PubMed1974

Mesentericocaval "jump" graft in management of portal hypertension: experience with 24 cases.

A series of 24 patients with cirrhosis have undergone mesentericocaval shunt operations for the relief of portal hypertension. Overall the results have been satisfactory. Four of the five patients treated as an emergency and 17 of the 19 who had the operation two to six weeks after haemorrhage had been controlled left hospital alive and well. Separation of the patients into three categories according to the findings of clinical and biochemical tests, however, showed that subsequent survival was satisfactory for patients in categories A and B but that all four patients in category C had died within one year after surgery. Assessment at three months showed that in three patients moderate hepatic encephalopathy had developed.Evidence that the shunt remains patent was shown by a low incidence of repeated gastrointestinal haemorrhage and a marked diminution in variceal size in 18 of the 19 cases examined serially. Radiographic techniques for confirming shunt patency were compared and cannulation of the graft via the femoral vein was found to provide a reliable and rapid means of assessment.

Adult↗
PubMed1973

Treatment of bleeding oesophageal varices by infusion of vasopressin into the superior mesenteric artery.

Seventeen patients bleeding from oesophageal varices were treated by continuous infusion of vasopressin through a catheter inserted percutaneously and positioned in the superior mesenteric artery and in two other patients catheterization proved technically impossible. Bleeding was completely controlled on only four out of 18 occasions in the 17 patients treated. In seven patients, bleeding was controlled for two or more days but then recurred although the infusion was continued with an increased dose of vasopressin. There was a high incidence of complications, including bleeding from the site of catheter insertion in the groin and septicaemias. Sengstaken balloon tamponade and oesophageal transection had to be used to control bleeding in some patients but only six out of 17 survived to leave hospital.

Adult↗