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Y Paz

Publications and source records attributed to Y Paz.

45 records · Page 3Linked to original sources
PubMed1996

Tumor necrosis factor-alpha is released from the isolated heart undergoing ischemia and reperfusion.

OBJECTIVES: The purpose of this study was to examine whether tumor necrosis factor-alpha (TNF-alpha) is released directly from the ischemic myocardium undergoing reperfusion. BACKGROUND: Tumor necrosis factor-alpha is a protein hormone produced by systemic leukocytes (primarily by activated macrophages). It has been implicated as a systemic mediator in the development of septic shock and other pathologic conditions. Serum TNF-alpha has also been detected in a variety of cardiac disease states and after myocardial ischemia-reperfusion injury. METHODS: Nine isolated rat hearts undergoing 30 min of perfusion, followed by warm cardioplegic arrest, 1 h of global ischemia and 30 min of reperfusion, were investigated using the modified Langendorff model. RESULTS: Significant amounts of TNF-alpha (752 +/- 212 pmol/ml) were detected in the effluent during the first minute of reperfusion. Tumor necrosis factor-alpha levels correlated with postischemic deterioration in peak systolic pressures (r = 0.7882, p = 0.012), dP/dt max (r = 0.6795, p = 0.044), time-pressure integral (r = 0.7661, p = 0.0016) and postischemic creatine kinase levels (r = 0.8367, p = 0.005). The deterioration in coronary flow, however, was inversely correlated with TNF-alpha levels (r = -0.7581, p = 0.018). CONCLUSIONS: To our knowledge, this study is the first to suggest that the isolated rat myocardium synthesizes and releases TNF-alpha in response to ischemia and reperfusion, which directly correlates with the postischemic deterioration in myocardial mechanical performance and the amount of cellular necrosis.

Animals↗
PubMed1996

Acute dystonic reaction to methotrimeprazine in hypoparathyroidism.

OBJECTIVE: To report a case of acute dystonic reaction to methotrimeprazine in a patient with untreated hypoparathyroidism, emphasizing the potential increased sensitivity of hypocalcemic patients to the extrapyramidal adverse effects of antipsychotic drugs. CASE SUMMARY: An 80-year-old man who had untreated hypoparathyroidism and chronic hypocalcemia developed an acute dystonic reaction 20 minutes after ingestion of methotrimeprazine 25 mg. His medical history included an ill-defined psychiatric disorder for which he had been treated with methotrimeprazine several years earlier. The patient denied having any other diseases or taking any other medications. After 4 days, the disorientation, psychomotor restlessness, dystonic grimacing, protrusion of the tongue, and speech difficulties disappeared, despite a remaining low serum calcium concentration. DISCUSSION: A possible mechanism, by which striatal calmodulin-mediated adenylate cyclase activation is inhibited by the combined effects of phenothiazines and hypocalcemia, is discussed. CONCLUSIONS: In this patient, it is not possible to ascertain whether the dystonic reaction was due to hypocalcemia, phenothiazine administration, or both. However, it is suggested that patients with hypocalcemia may be sensitive to the extrapyramidal adverse effects of antipsychotics. In addition, acute unexpected dystonic reactions to a small dose of antipsychotics warrants measurement of the patient's serum calcium concentration.

Aged↗
PubMed1994

Conjoined double internal mammary artery grafting.

Double internal mammary artery (IMA) grafting to the coronary arteries was performed on 82 patients. In ten of them one IMA was used as a free graft, and was proximally connected to the other ("conjoined" double IMA), the indications being insufficient supply of adequate veins, diseased aortic wall, availability of only a short right IMA segment for free grafting, occluded left subclavian artery, and when distal and scattered lesions of relatively important vessels had to be bypassed. Additional sequential IMA anastomoses were performed in four patients and an additional sequential vein graft in a fifth. All patients became angina-free postoperatively and have remained so during observation up to 16 months. Recatheterization studies were performed in six patients and in all of them the IMA-to-IMA (n = 6) and distal anastomoses (n = 26) were patent. Conjoined double IMA grafting is an important option available to the cardiac surgeon for management of selected patients with coronary artery disease.

Cardiac Catheterization↗
PubMed1994

Aprotinin improves myocardial recovery after ischemia and reperfusion. Effects of the drug on isolated rat hearts.

The effects of aprotinin, a protease inhibitor, on the ischemic and nonischemic isolated rat heart was investigated with the use of the modified Langendorff model. During phase I of the study, hearts were perfused with either low-dose aprotinin (10(5) KIU/L), high-dose aprotinin (10(6) KIU/L), or normal saline solution added to modified Krebs-Henseleit solution. No statistically significant differences in contraction amplitude, contractility, coronary flow, and wet/dry heart weight ratio were observed among the three groups of hearts. In phase II, hearts were exposed to a 40-minute period of global ischemia at 31 degrees C. Ischemic arrest was induced by warm cardioplegia. Before ischemia and during cardioplegia, hearts were perfused with either aprotinin 10(6) KIU/L (n = 10) or normal saline solution (n = 10) for 30 minutes. On reperfusion, recovery of hearts treated with aprotinin was significantly better than that of control hearts, as reflected by better contractility (analysis of variance, p = 0.011), higher coronary flow (p < 0.025), and lower creatine kinase levels (p < 0.05). No statistically significant differences in contraction amplitude were observed between the two groups. When the effect of ischemia within each group of hearts was analyzed, the preserving effect of aprotinin was even more pronounced. In the control group, ischemia caused a decrease in contractility (p < 0.025) and a decrease in oxygen consumption (p = 0.006); by contrast, in the aprotinin group the preischemic values were maintained. Accordingly, we conclude that aprotinin at concentrations up to 10(6) KIU/L has no deleterious effect on normally perfused hearts and has a significant protective effect on the ischemic heart when used in high doses in the preischemic period.

Animals↗
PubMed1994

Role of protease inhibition in myocardial preservation following ischemia and reperfusion.

Aprotinin, a naturally occurring protease inhibitor, in concentrations of 10(6) KIU/L was found to have no effect on myocardial performance in normally perfused isolated rat hearts, before ischemia. Given during the preischemic period, the drug had a significant protective effect on the reperfused hearts, following cardioplegic ischemia: better contractility upon reperfusion (p < 0.011), faster decline of the ischemic contracture, higher coronary flow (p < 0.025), lower AV-difference (p < 0.05), and lower CPK levels (p < 0.01).

Animals↗
PubMed1994

Arterial revascularisation with the conjoined double internal mammary artery grafting.

A free graft Internal Mammary Artery (IMA) was proximally connected end-to-side to an in-situ IMA in 6 patients, a method we have named: "The conjoined double IMA". This alternative surgical technique was applied in patients where important vessels had to be grafted in presence of diseased aortic wall, insufficient supply of adequate veins, or a mammary not long enough, thus precluding the performance of other, more conventional methods for Double IMA grafting. Early clinical and angiographic follow-up demonstrate the feasibility of this technique in selected patients.

Aged↗
PubMed1991

Multiple family member visits to family physicians. Terminology, classification, and implications.

A study was designed to investigate "the family as the unit of care" in family medicine consultations from the patient's end of the physician-patient axis, unlike most previous related studies, which have concentrated on it from the physician's perspective. During 2 separate weeks in November 1987 and February 1988, nine Israeli family physicians collected demographic and family-related data concerning the spontaneous visiting patterns generated by 1156 persons (899 patients and 257 nonpatients) who attended 796 separate consultations at their clinics during this time. More than one patient attended 12% of the consultations, and more than one person, patient or nonpatient, was present at 36%. At 31% of the consultations children alone or children and adults were recorded as patients (child consultations), and at 69% only adult patients were present (adult consultations). Adults were recorded as second or third patients at 19% of the child consultations but at only 5% of the adult consultations. The child consultations alone yielded 86% of all the nonpatients documented. Basic terminology and methodology for investigating such multiple family member visits to family physicians is discussed as well as the composition of the different family units encountered and their possible significance.

Adult↗
PubMedDate not supplied

Comparison of vasoactive response of left and right internal thoracic arteries to isosorbide-dinitrate and nitroglycerin: an in vitro study.

OBJECTIVE: The internal thoracic artery (ITA) is the most important graft in coronary artery bypass grafting. Its distal region is, however, prone to vasospasm. We studied the effects of nitroglycerin (NTG) and isosorbide-dinitrate (DSDN) on distal segments of left versus right ITA. METHODS: Rings of distal segments (6 to 9 mm proximal to bifurcation) of the human left and right ITA were studied. After baseline contraction of the rings, achieved using 60 mmol/L of KCl, they were exposed to increasing doses of ISDN and NTG (10 to 100 microg/ml), and dose-response curves were recorded. RESULTS: The contractile response of left ITA rings to KCl were significantly lower than those of right ITA rings (1.87 +/- 0.25 g versus 3.5 +/- 0.61 g, p < 0.005). Both nitrates inhibited the contractile response in a concentration-dependent manner, with relaxing effects of ISDN higher than those of NTG (p < 0.01) in both left and right ITA rings. CONCLUSIONS: The distal segment of the left ITA is less prone to vasospasm than that of the right. ISDN has a considerably higher relaxant effect on this segment than NTG. We therefore recommend favoring high doses of ISDN over NTG as an antispastic measure.

Coronary Artery Bypass↗