Sudden, Severe Mitral Insufficiency

Five male patients with sudden, severe mitral insufficiency due solely to ruptured chordae tendineae or papillary muscle had an abrupt onset of symptoms of left and right heart failure and the sudden appearance of a harsh, widely propagated apical pansystolic murmur. None had a history of rheumatic fever. All were in sinus rhythm and had but mild left atrial and ventricular enlargement. Giant left atrial “v” waves were characteristic and exceeded pulmonary artery pressure in two instances.

In contrast, when ruptured chordae tendineae were superimposed on chronic rheumatic mitral insufficiency, females predominated and there was a long history of disability. Atrial fibrillation, less elevation of left atrial pressure, and marked left atrial and ventricular enlargement were characteristic. These latter patients closely resembled patients with chronic rheumatic mitral insufficiency alone.

It is concluded that the syndrome of sudden, severe mitral insufficiency develops if ruptured chordae tendineae occur on a previously normal or insignificantly diseased mitral valve. If ruptured chordae tendineae are superimposed on chronic rheumatic mitral insufficiency, the syndrome resembles that seen in the latter alone.

     

5-year survival after multiple repeat metastasectomy for pulmonary artery angiosarcoma

Primary pulmonary artery angiosarcomas are rare malignant tumors with few reported survivors. We report a case of a 39-year-old woman without evidence of disease 5 years after initial diagnosis and after multiple metastasectomies and pulmonary artery tumor endarterectomy.     

Naratriptan: biological profile in animal models relevant to migraine

The biological profile of naratriptan (N-methyl-3-(1-methyl-4-piperidinyl)-1H-indole-5-ethane-sulphona-mide), a novel 5HT_1B/1D receptor agonist, was investigated in a variety of experimental models of relevance to migraine. Naratriptan has high affinity for human recombinant 5HT_1B and 5HT_1D receptors (pKi = 8.70.03 and 8.30.1, respectively) and causes contractions of dog isolated basilar and middle cerebral artery (EC₅₀ values of 0.11 and 0.07 M, respectively). Naratriptan causes small contractions of human isolated coronary arteries (EC₅₀ value of 0.17 M; maximum contraction equivalent to 33% of 5HT maximum). In anaesthetized dogs, naratriptan causes selective vasoconstriction of the carotid arterial bed (CD₅₀ dose = 193 g kg⁻¹) and, in anaesthetized rats, naratriptan selectively inhibits neurogenic plasma protein extravasation in the dura (ID₅₀ = 4.1 g kg⁻¹). In a variety of antinociceptive tests, naratriptan has no effect even at high doses. In conscious rats and dogs, naratriptan has high oral bioavailability (71% and 95%, respectively). The data show that naratriptan is a selective agonist at 5HT_1B/1D receptors, with a pharmacological profile very similar to that of sumatriptan, albeit 2-3 fold more potent. These observations, coupled with high oral bioavailability in animals, suggest that naratriptan has the profile of an orally effective anti-migraine drug.     

A highly sensitive and specific chemiluminescent enzyme-linked immunosorbent assay for diagnosis of active Trypanosoma cruzi infection

BACKGROUND: Chagas' disease is transmitted to man either by the bite of insects harboring Trypanosoma cruzi or by the transfusion of blood from infected donors. The conventional serologic testing as presently used in blood banks in South America is unsatisfactory, because of a high number of inconclusive and false-positive results. Other methods such as polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA) with recombinant antigens have been proposed, but inherent difficulties have so far precluded their adoption in the large-scale screening required by blood banks. STUDY DESIGN AND METHODS: A highly sensitive and specific chemiluminescent ELISA using a purified trypomastigote glycoconjugate antigen and a complex epimastigote antigen was devised for the diagnosis of active T. cruzi infection. RESULTS: Chemiluminescent ELISA was 100-percent sensitive in the diagnosis of 100 cases of confirmed Chagas' disease. Inconclusive results and false-positive reactions were eliminated in a panel of 115 sera.The specificity of the chemiluminescent ELISA was 100 percent with a purified trypomastigote glycoconjugate antigen and 99.7 percent with a complex epimastigote antigen when applied to 1000 normal human sera and 288 heterologous sera from patients with other infections, including leishmaniasis, and vaccinated individuals. CONCLUSION: The chemiluminescent ELISAs provide a test that is highly sensitive (purified trypomastigote glycoconjugate and complex epimastigote antigens) and specific (purified trypomastigote glycoconjugate antigen) for Chagas' disease diagnosis. It can be used in blood bank screening and to monitor the treatment of patients undergoing chemotherapy.     

Computer-assisted reporting system for the follow-up of patients with prosthetic heart valves

The implantation of large numbers of prosthetic heart valves carries with it the responsibility for continual reassessment of all aspects of patient management. Experience with more than 2,000 prosthetic valve operations since 1963 led to the development of a comprehensive computer-assisted data collection, management and reporting system. Over a 5 year period, data forms were developed for the detailed documentation of preoperative, intraoperative and postoperative information. These were designed in the form of checklists suitable for direct computer entry with use of mark-sense document readers. Special emphasis was placed on preoperative assessment of ventricular function, valve selection, intraoperative myocardial preservation, postoperative rehabilitation and prosthetic valve-related complications. This system makes possible rapid computer generation of a variety of reports to the referring physician regarding the individual patient and to the clinical investigator in relation to patient group statistics. Also, questionnaires to patients or physicians, or both, to update patient data can be produced by the computer at appropriate intervals after valve surgery. Experience indicated that a computer-assisted methodology is the only practical way to provide adequate follow-up of large groups of patients. Additionally, direct access to relevant information helps to create an environment in which essential research can be carried out in the face of a demanding clinical practice.     

Detection and heterogeneity of herpesviruses causing Pacheco's disease in parrots

Pacheco's disease (PD) is a common, often fatal, disease of parrots. We cloned a virus isolate from a parrot that had characteristic lesions of PD. Three viral clones were partially sequenced, demonstrating that this virus was an alphaherpesvirus most closely related to the gallid herpesvirus 1. Five primer sets were developed from these sequences. The primer sets were used with PCR to screen tissues or tissue culture media suspected to contain viruses from 54 outbreaks of PD. The primer sets amplified DNA from all but one sample. Ten amplification patterns were detected, indicating that PD is caused by a genetically heterogeneous population of viruses. A single genetic variant (psittacid herpesvirus variant 1) amplified with all primer sets and was the most common virus variant (62.7%). A single primer set (23F) amplified DNA from all of the positive samples, suggesting that PCR could be used as a rapid postmortem assay for these viruses. PCR was found to be significantly more sensitive than tissue culture for the detection of psittacid herpesviruses.     

Premature deaths in Canada: impact, trends and opportunities for prevention

The impact, time trends and potential for prevention of premature deaths in Canada were assessed. There were almost 100,000 deaths before age 75 in Canada during 1986 resulting in over 1.7 million potential years of life lost (PYLL). The three leading broad disease categories responsible for PYLL were cancer, injuries/violence and cardiovascular disease. In both sexes, coronary heart disease, car accidents, lung cancer and perinatal conditions ranked in the top 5 specific diseases responsible for PYLL; breast cancer (females) and suicide (males) also ranked in the top 5 conditions. Over the period 1969 to 1986, death rates among persons less than age 75 increased for 3 conditions among females and 11 conditions among males. Lung cancer and brain cancer death rates increased in both sexes, chronic obstructive pulmonary disease death rates increased among females only and death rates for suicide and 8 types of cancer increased among males only. Over the same period, death rates declined for 37 discrete disease categories among both females and males including particularly large improvements for coronary heart disease, stroke, car accidents and perinatal conditions. An estimated 50,000 or over 50% of all premature deaths per year are preventable through control of smoking, hypertension, elevated serum cholesterol, diabetes and alcohol abuse. About 6,000 premature deaths are avoidable through improvements in medical care.