Endothelin (ET-1) was synthesized by solid-phase peptide synthesis. To prevent side reactions with tryptophan residue, a formyl group was used to protect the beta-indole moiety. The two disulfide bridges were formed selectively using S-methylbenzyl for the cysteine residues in positions 3 and 11, and S-acetamidomethyl for positions 1 and 15. Crude synthetic ET-1 was obtained after deprotection and cleavage from the resin by HF, followed respectively by potassium ferricyanide and iodine oxidations, in order to generate sequentially the monocyclic and bicyclic forms of the peptide. Finally, Trp(For) was deprotected by a treatment with piperidine. After each step, a sample of peptide was isolated and purified by RP-HPLC. The biological activity of these synthetic peptides was evaluated on guinea pig tracheal strips. The results suggest that oxidation of Met-7 and/or formylation of Trp-21 do not affect the biological activity of ET-1 in the guinea pig trachea. Moreover, although a decrease of potency and intrinsic activity was observed, the monocyclic analog containing Cys(Acm) residues at positions 1 and 15 exhibited substantial constrictor activity. This result, contrasting with that observed with several vascular preparations, suggests that the guinea pig trachea contains a distinct ET receptor population.

Animals↗

PubMedDate not supplied

Patient attitudes and psychological considerations in dialysis discontinuation.

The authors surveyed 36 adult patients who were maintained with chronic renal dialysis concerning their attitudes about dialysis discontinuation. Few subjects reported having ever considered stopping the life-support treatment. When asked to consider 12 hypothetical scenarios in which they might consider stopping treatment (e.g., onset of dementia or blindness), most subjects would still not consider discontinuation. Consideration of dialysis discontinuation was directly correlated with the patient's educational level. Follow-up after 1 year underscored the substantial differences between the responses the subjects gave to the 12 hypothetical scenarios and their real-life responses when they were later faced with decisions to actually terminate treatment. Psychiatrists have an opportunity to participate in the complex clinical and ethical decisions associated with advance directives and patients' right to refuse life-support treatment.

Adult↗

PubMedDate not supplied

Denying the dying. Advance directives and dialysis discontinuation.

A structured interview was administered to a sample of patients on maintenance dialysis and their attending physicians to obtain information on the documentation of their end-of-life treatment preferences. The majority of the patients reported never having considered stopping dialysis, or having discussed with their nephrologist or family the circumstances in which treatment should be discontinued. Only 7 patients (6%) had completed an advance directive; these patients were all men (P = 0.01) and tended to be better educated (P = 0.02). Only one of the nine physicians had completed an advance directive. In most cases, the dialysis patients and their treatment team staff were preoccupied with the struggles of daily life and had avoided or denied considerations of terminal illness and death. The literature on denial, medical illness, and dying is also reviewed as it relates to dialysis patients, end-of-life treatment, and terminal care.

Adult↗

PubMedDate not supplied

[Surgey of tick-borne arboviruses in the Central African Republic (1973-1974). Isolation of Dugbe, CHF/Congo, Jos and Bhanja viruses].

As a complement of the study of the epidemiology of the arboviruses in Central Africa a survey of tick borne viruses has been done, in the Central African Republic, from December 1972 to June 1974; 15.103 ticks were collected, mainly from cattle at the slaughterhouses. They include: 10.085 Ambylomma variegatum, 4.113 Boophilus, 542 Rhipicephalus and 363 Hyalomma. From 892 monospecific pools inoculated into baby mice, 98 isolates of virus were obtained. Among the 57 isolates which have been fully identified (the identification of 41 other isolates is still in progress), 4 different serotypes of arbovirus have been found: Dugbe virus has been the most frequently found with 45 isolates from A. variegatum and I from B. decoloratus; this virus, previously isolated from human cases in Central African Republic in 1967 and 1970 has been isolated from a new human case in 1973. One isolate of CHF/Congo virus has been obtained from Hyalomma nitidum, but this virus has not yet been isolated from human beeings in C.A.R. The two other tick borne viruses isolated during this survey are Jos virus (9 isolates) and Bhanja virus (I isolate), all of them from A variegatum.

Animals↗

PubMedDate not supplied

[Isolation of Thogoto virus from Amblyomma and Boophilus ticks in Central Africa].

A survey has been carried out in the Cameroons and the Central African Republic about the role of the ticks in the ecology of arboviruses in Central Africa. Attempts for virus isolation were made for 12,678 Amblyomma variegatum, 3,276 Boophilus decoloratus and 1,769 Boophilus annulatus, by inoculation into suckling mice. From 968 pools which were inoculated, 20 yielded isolates which were identified to Thogoto virus. Considering previously published results concerning tick-borne virus isolations in the Central African Republic, it appears now that five arboviruses are present in the ticks in central Africa : Dugbe, Jos and Thogoto (in A. variegatum, B. decoloratus and B. annulatus), Bhanja (in A. variegatum) and Chf. Congo (in Hyalomma nitidum).

Africa, Central↗

PubMedDate not supplied

[Experimental portal hypertension in the dog].

Portal hypertension may be obtained in the dog at three levels: by blocking the venous circulation either above, within or below the liver. Portal hypertension by venous obstruction below the liver is obtained by partial ligature of the portal vein using a ring covered with talcum powder. The fibrous reaction thus created causes occlusion of the portal vein in 50 p. 100 of cases. This portal hypertension is transient and is not accompanied by oesophageal varices. The special anatomical lay-out of the portal system in the dog, explains these findings.

Animals↗

PubMedDate not supplied

[Granular cell myoblastoma or Abrikosov's tumor of the esophagus].

Granular cell myoblastoma or Abrikossoff's tumor of the esophagus are exceptional: fiveteen cases have been described in the literature. In this work we present the following case: discovery of a sub mucosal tumor during a systematic fibroscopic examination of an anemix patient. Only histological examination was able to make the diagnosis.

Adult↗

PubMedDate not supplied

[Porcelain gallbladder and cancer (author's transl)].

The porcelain gallbladder is a rare entity. It reaches especially the old woman. Most of the porcelain gallbladders have a great clinical latence. A cancer of the gallbladder exists in eleven per cent of the cases: this justifies a systematic cholecystectomy of the calcified gallbladders, even if they are asymptomatic. Another digestive cancer exists in nine per cent of the cases. Three personal observations of porcelain gallbladder which are associated with a cancer are described: they confirm the facts of the literature.

Aged↗