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Biomedical subjects

F Johnston

Publications and source records attributed to F Johnston.

At least 37 records · Page 2Linked to original sources

Adenocarcinoma of Meckel's cave: case report.

A rare localization of adenocarcinoma in Meckel's cave is reported in a 58-year-old woman, who had a 5-month history of pain and altered sensation in the second division of the left trigeminal nerve. Removal of the lesion was achieved by a subtemporal route. Histology showed this to be an adenocarcinoma. The patient underwent investigations for a primary tumor; the investigations were all negative, and the patient was subsequently treated with a course of radiotherapy. At 4-month follow-up, there was no evidence of recurrence, and she remains symptomatically well. The various mechanisms of secondary localization are discussed.

Adenocarcinoma↗

Malignant paraganglioma of the glomus jugulare: a case report.

Jugular paragangliomas are noted for their tendency to recur, but frank malignant behaviour is rare. We report a case in which a patient harbouring a recurrent tumour of the glomus jugulare re-presented with metastatic spread to mediastinal lymph nodes. Review of the 16 reported cases provides information which can be a basis for management of the malignant form of this tumour.

Female↗

Training volunteers to work with the chronic mentally ill in the community.

The psychiatric literature gives evidence supporting the use of volunteers in caring for chronic psychiatric patients in the community. Thorough training of volunteers can be expected to enhance the quality of care they provide and help them to maintain interest in their role. The ten-week training program described in this paper was designed to increase volunteers' knowledge of mental illness, improve the quality of care they provided, and stimulate interest in the volunteer role. Pre- and posttraining scores on a questionnaire indicated that volunteers' knowledge had increased. The volunteers rated most aspects of the training very highly and felt that the orientation had helped them meet their goals. Several volunteers indicated increased tolerance for the mentally ill. Many questions remain unanswered. For example, in the long run, what difference does such training make for the patients with whom the volunteers work? Will reluctant professionals be more willing to refer patients to volunteer-staffed programs if those volunteers have had intensive training? Is the training cost-effective? We feel that the potential benefits of volunteers working with the chronic mentally ill in the community make this an important area for future research.

Chronic Disease↗

Binding of Escherichia coli RNA polymerase to a promoter carrying mutations that stop transcription initiation.

The gal P2 promoter can be inactivated by point mutations located in the -10 hexamer sequence or immediately upstream from it. Mutations at either site reduce expression in vivo and prevent the formation, in vitro, of tight complexes with RNA polymerase that give a strong footprint and can initiate transcription. However, with a mutation upstream from the -10 region, RNA polymerase could still make a specific contact with gal promoter DNA as judged by interference with cleavage by restriction enzyme SfaNI at a site within the promoter. In contrast, with a mutation in the -10 hexamer sequence, RNA polymerase could not make this contact and does not interfere with restriction by SfaNI.

Base Sequence↗

24-hour electrocardiographic study of heart rate and rhythm patterns in population of healthy children.

Twenty-four hour electrocardiographic recordings were made on 104 randomly selected, healthy 7 to 11-year-old children. Ninety-two were technically adequate and suitable for analysis. The mean highest heart rate measured by direct electrocardiographic analysis over nine beats was 164 +/- 17. The mean lowest heart rates were 49 +/- 6 over three beats', and 56 +/- 6 over nine beats' duration. The maximum duration of heart rates less than 55/minute was 40 minutes. At their lowest heart rates 41 children (45 per cent) had junctional escape rhythms, the maximum duration of which was 25 minutes. Nine children showed PR intervals greater than or equal to 0.20 s and included three with Mobitz type I second degree atrioventricular block. Nineteen (21%) had isolated supraventricular or ventricular premature beats (less than 1/hour). Sixty subjects (65%) had sinus pauses that could not be distinguished on the surface electrocardiogram from those previously described as sinuatrial exit block or sinus arrest. The maximum duration of sinus pause measured over 24 hours on each child was 1.36 +/- 0.23 seconds. Thus apparently healthy children show variations in heart rate and rhythm over 24 hours hitherto considered to be abnormal.

Child↗

Transient ischemic attacks: a prospective study of 225 patients.

Between the years 1964 and 1973, 225 patients with transient ischemic attacks (TIAs) due primarily to atherosclerosis were evaluated and treated. They have now been followed for from 3 to 14 years (average 5.5 years). As of 1976, 82 of the 225 patients were dead, 21 from cerebral infarction, 52 from heart disease and nine from other causes. Of the 56 untreated patients, 11 (19 percent) had cerebral infarctions, four (7 percent) of which were fatal; six (11 percent) were still having TIAs. Of the 45 patients medically treated, 10 (24 percent) had cerebral infarctions, three (7 percent) of which were fatal; 11(25 percent) still experienced TIAs. In the surgical group of 124, 27 (21 percent) had postoperative cerebral infarctions, seven (6 percent) of which were fatal; 23 (18 percent) had cerebral infarctions during follow-up, of which seven (6 percent) were fatal; and 15 (12 percent) were still having TIAs. No statistically significant differences (p less than 0.05) related to cerebral infarction or TIAs developed among the three groups. The majority (23 percent) eventually succumbed to myocardial infarction, leading us to conclude that great emphasis must be placed upon TIAs as a warning for cardiac as well as cerebrovascular disease.

Aged↗

Transient ischemic attacks due to atherosclerosis. A prospective study of 160 patients.

Patients with transient ischemic attacks (TIAs) due to atherosclerosis were studied by aortocranial arteriography. Onset of TIAs was before age 55 in 24% and between 55 and 64 in 47%. Men exceeded women by two to one. Of 160 patients, 77 were treated medically and 82 surgically. Five died in the immediate postoperative period. In the survivors, mortality has been the same in the medically and surgically managed groups. For patients with multiple lesions, surgical reconstruction of the carotid arteries was associated with very high surgical risk. In the medically treated group, anticoagulant therapy reduced the frequency of TIAs, but did not appear to protect patients from stroke. Mortality was 23% at four years, 57% of deaths being attributable to myocardial infarction and 38% to stroke.

Adult↗

Secular trends in male adult height 1904-1996 in relation to place of residence and parent's educational level in Portugal.

The records of height of 22841 18-year-old Portuguese males were analysed as well as their parents educational level and localities of subject's residence (districts). The sample includes all the Portuguese 18-year-old males, born in 1978 and examined in 1996, in central and southern Portugal, representing all the social strata. Statistically significant differences (p < or = 0.001) among the districts were found: males from Setúbal (172.75 cm) and Lisboa (172.64 cm), the most developed districts, are the tallest, and those from C. Branco (170.79cm) and Coimbra (171.19 cm) are the shortest. Comparing to published data from 1904, a positive secular trend in height was found. The average increase was 8.99 cm, which yields a rate of 0.99 cm per decade. This positive trend must be related to the general improvement in the population's standard living conditions, as the striking drop of post-neonatal mortality rate shows after the 1960s and 1970s. Despite this positive trend, great social difference still exists: the gap between the two extremes of parents' educational level is almost 4 cm for height. Analysis of variance (ANOVA) showed significant effects of father's and mother's educational level as well as subject's locality of residence, but the influence of parents' educational level was stronger than that of geographic residence. These results suggest that the secular trend in height will continue for the Portuguese population in the future decade.

Adolescent↗