Coronary reoperations: indications and results

The aim of this study was to assess the results of coronary reoperations and to determine the indications. Between January 1972 and December 1990, 166 coronary reoperations were performed in 161 patients (5 patients were operated three times). The interval between the first and second operation was 93 +/- 46 months. The interval between recurrence of symptoms and reoperation was 27 +/- 40 months. Recurrence of symptoms was related to isolated problems with the bypass grafts in 23% of cases, to an aggravation of the coronary disease without problems with the bypass grafts in 17% of cases and to an association of the two conditions in 60% of cases. Mortality in the first 30 postoperative days was 7.8% (13/161). The predictive factors of mortality were age over 70 years and an interval between recurrence of symptoms and reoperation of over 12 months. The causes of death were myocardial infarction (n = 5), left ventricular failure (n = 4), sudden death (n = 3), and arrhythmias (n = 1). The average follow-up period of survivors (n = 134) was 40 +/- 32 months. Four patients have been transplanted. Seven patients died secondarily. The cause of death was cardiac in 4 cases and non-cardiac in 3 cases. The actuarial 5 year and 10 year survival rates were 85 +/- 3%. Actuarial absence of myocardial infarction, angina, Class III-IV cardiac failure and transplantation was 87 +/- 4% at 5 years and 69 +/- 10% at 10 years. These figures show that coronary reoperation gives good functional results and long-term survival.(ABSTRACT TRUNCATED AT 250 WORDS)     

Salt wastage, plasma volume contraction and hypokalemic paralysis in self-induced water intoxication

Eleven episodes of severe hyponatremia secondary to hiccup-induced potomania were recorded in 3 years in a man who had essential hypertension, a low protein intake and a normal diluting ability. Paradoxical increase in hematocrit and plasma protein with acute extensive natriuresis was associated as well as urine potassium loss and hypokalemia producing paralysis in 1 episode. During a chronic water loading test, the defect in water excretion was related to a low urine solute delivery which was partially reverted by the natriuretic response to plasma volume expansion, promoting water diuresis. In acute water intoxication, this natriuretic response was exaggerated, producing a brisk water diuresis. Plasma volume was rapidly normalized but without any improvement in plasma sodium due to the concomitant negative sodium balance. Thus, water diuresis persisted until plasma volume was significantly contracted. Potassium loss appeared to be related to sodium excretion. Metabolic disturbances have not reoccurred despite persistent hiccup and potomania during 2 years of urea therapy.     

Range of neuromuscular involvement in 47 patients infected with the human immunodeficiency virus

Over a 30 month period, 47 out of 749 patients infected with the human immunodeficiency virus had various neuromuscular symptoms. Based on clinical and electrophysiological data, 47% had distal symmetric polyneuropathy, 11% chronic inflammatory demyelinating polyneuropathy (CIDP), 8.5% toxic neuropathy related to 2-3-dideoxyinosine (DDI), 8.5% cranial neuropathy, 8.5% mononeuropathy multiplex or isolated focal neuropathy, 8.5% progressive lumbosacral polyradiculopathy, and 8.5% myopathy. Half of the patients exhibited previous or concomitant signs of central nervous system involvement and 18 patients died during the study period. CIDP and cranial neuropathies usually appeared early in the course of the disease and consequently showed neurological improvement. Nerve conduction studies of DDI related toxic neuropathies showed distal axono-myelinic sensitivo-motor neuropathy, differing from CIDP by the absence of a conduction block. Distal symmetric polyneuropathies, frequent in the advanced systemic illness, do not systematically require an extended workup, but more unusual peripheral neuropathies which might be treatable necessitate further investigations (electromyography, radiology, serological blood tests; protein chemistry and routine workup of the cerebrospinal fluid). For example, progressive lumbosacral polyradiculopathies responded to early treatment, with a better outcome in one case of herpetic origin than in another case due to cytomegalovirus infection. Our observations suggest that myopathies in HIV infected patients should first be tackled by temporary interruption of virostatic medication, followed by muscle biopsy if the symptoms persist.     

Sperm morphology as diagnosed by strict criteria: probing the impact of teratozoospermia on fertilization rate and pregnancy outcome in a large in vitro fertilization population

OBJECTIVE: To investigate the predictive value of sperm morphology assessed by strict criteria on IVF outcome. DESIGN: Retrospective analysis of all IVF cycles (January 1987 to December 1992). MAIN OUTCOME MEASURES: All patients were assigned to one of three groups based on sperm morphology: P-pattern (< 4% normal forms), G-pattern (4% to 14% normal forms), and N-pattern (> 14% normal forms). Morphology pattern was related to other semen characteristics and IVF outcome. RESULTS: Despite corrective measures at oocyte insemination, the fertilization rate was significantly different among the three morphology groups, P < G < N. N-pattern sperm produced a mean fertilization rate over 85% regardless of low motility or concentration. In a cohort study, P-pattern cycles produced a lower implantation rate and lower ongoing pregnancy rate, independent of the lower fertilization rate. CONCLUSIONS: Strict morphology is an excellent biomarker of sperm fertilizing capacity, independent of motility and concentration. P-pattern sperm may denote a poorer prognosis for establishing a pregnancy, even after a satisfactory fertilization rate is achieved.     

Unrepaired heteroduplex DNA in Saccharomyces cerevisiae is decreased in RAD1 RAD52-independent recombination

A direct repeat recombination assay between SUP4 heteroalleles detects unrepaired heteroduplex DNA (hDNA) as sectored colonies. The frequency of unrepaired heteroduplex is dependent on the mismatch and is highest in a construct that generates C:C or G:G mispairs and lowest in one that generates T:G or C:A mispairs. In addition, unrepaired hDNA increases for all mismatches tested in pms1 mismatch repair-deficient strains. These results support the notion that hDNA is formed across the SUP4 repeats during the recombination event and is then subject to mismatch repair. The effects of various repair and recombination defective mutations on this assay were examined. Unrepaired heteroduplex increases significantly only in rad52 mutant strains. In addition, direct repeat recombination is reduced 2-fold in rad52 mutant strains, while in rad51, rad54, rad55 and rad57 mutants direct repeat recombination is increased 3-4-fold. Mutations in the excision repair gene, RAD1, do not affect the frequency of direct repeat recombination. However, the level of unrepaired heteroduplex is slightly decreased in rad1 mutant strains. Similar to previous studies, rad1 rad52 double mutants show a synergistic reduction in direct repeat recombination (35-fold). Interestingly, unrepaired heteroduplex is reduced 4-fold in the double mutants. Experiments with shortened repeats suggest that the reduction in unrepaired heteroduplex is due to decreased hDNA tract length in the double mutant strain.     

Immunochemical isolation and characterization of vitellogenin mRNA from liver of estradiol-treated chicks

Several commercially available samples of galactose oxidase (D-galactose: oxygen 6-oxidoreductase, EC 1.1.3.9) were found to contain high proteolytic activity on proteins such as fibrinogen, transferrin, albumin and casein. A simple, efficient method was devised for the purification of galactose oxidase which relies on the affinity of the enzyme for agarose (Sepharose 6B). The purified galactose oxidase was recovered in high yield free from proteolytic activity. The enzymic affinity for Sepharose and Sephadex was investigated to clarify the absorption mechanism.     

Quantitative measurement of cationic fluxes, selectivity and membrane potential using liposomes multilabelled with fluorescent probes

Liposomes of egg PC/PG (8:2, mol/mol) were multilabelled with PBFI, pyranine and oxonol VI, fluorescent probes for, respectively, K+, H+ and membrane potential. Monitoring fluorescence with a multichannel photoncounting spectrofluorometer during K+ filling experiments allowed to measure K+ influx, the associated H+ efflux and the membrane potential, continuously and simultaneously. The proton net efflux quantitatively mirrored the K+ net influx. The rate of the K+/H+ exchange diminished progressively as a quasi-equilibrium was reached for both K+ and H+. In the presence of valinomycin, the measured membrane potential during the K+ filling actually corresponded to the Nernst potential calculated from the observed K+ gradient. In the absence of valinomycin, it corresponded to the Nernst potential calculated from the observed H+ gradient. In the latter case, the permeability coefficient of liposomes to K+, calculated from the Goldman-Hodgkin-Katz relation, was 6.10(-13) m s-1. The selectivity sequence for alkali cations of liposomes was determined from the measured H+ efflux associated to the influx of the different cations. The selectivity sequence corresponded to the series VI of Eisenman, suggesting interaction of the cation with an anionic field of intermediate strength.