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Biomedical subjects

W Haider

Publications and source records attributed to W Haider.

At least 37 records · Page 2Linked to original sources
PubMed1995

Breast cancer in pregnant and lactating women.

Between 1988 and 1991, we treated 595 women with breast cancer in the Breast Disease Section of the Cancer Research Foundation of Pakistan. We report here on 61 patients who were pregnant or lactating. Most patients presented at a late stage of disease because of ignorance, social taboos, or fear of hospitalization and operation. The largest diameter of the breast mass at presentation was 15 cm. Lymph nodes were involved in 70.5% of cases. Multiparity, young marriages, malnutrition, and unhygienic conditions are ripe in the rural environment of Pakistan. No oral contraceptives are used. Modern and conventional methods of treatment did not increase the survival rate of these cancer patients.

Adult↗
PubMed1994

Postischemic hemodynamic changes after piroximone administration in isolated rabbit heart.

In an experimental study on 22 adult Elco rabbits, hemodynamic parameters were investigated using a working heart model. The study group (10 rabbit hearts) received 1 mg/kg i.v. of the phosphodiesterase inhibitor piroximone 15 min before thoracotomy. 12 untreated rabbit hearts served as a control group. Hemodynamic parameters were measured before and after 60 min of hypothermic ischemia. The pre-ischemic period showed no significant differences between the two groups, except the higher levels of coronary flow in the piroximone group. The postischemic period showed significant increases in heart rate, coronary flow, aortic flow and cardiac output in the piroximone group in comparison to the control group. These results indicate as a main effect the positive influence of piroximone on coronary flow, given as a single shot 15 min preoperatively. This study provides evidence of the vasodilative properties on the coronary arteries beside the documented effects on the periphery. Therefore, piroximone represents an alternative tool in weaning from the cardiopulmonary bypass.

Animals↗
PubMed1994

Pathologic findings of experimentally induced Streptococcus uberis infection in the mammary gland of cows.

Twenty-five quarters of 12 dairy cows, 3 to 8 years old, with a bacteriologic history of freedom from infection with Streptococcus uberis were inoculated via the teat canal with S uberis (23 quarters) or sterile medium (2 quarters). The cows were sent to slaughter 1, 3, or 6 days later. Acute inflammatory response involving accumulation of large numbers of polymorphonuclear, neutrophilic leukocytes (neutrophils) in the secretory acini was recognized after 24 hours in infected cows. After 6 days, the neutrophil response was still evident, but infiltration of septa by lymphocytes, septal edema, extensive vacuolation of secretory cells, focal necrosis of alveoli, small outgrowths of the secretory and ductular epithelium, and widespread hypertrophy of the ductular epithelium also were recognized. Early stages of involution and fibrosis also were evident at that stage. Streptococci were identified by immunoperoxidase labeling, free or phagocytosed, in macrophages; in the alveolar lumina, adherent to damaged secretory or ductular epithelium; in the subepithelium and septal tissue; and in lymphatic vessels and lymph nodes. The importance of the macrophage as the primary phagocytic cell is highlighted, and doubt is cast on the value of the exuberant neutrophil response by the host in defense of the gland.

Animals↗
PubMed1994

Cardioprotection by nifedipine cardioplegia during coronary artery surgery.

In a double-blind, placebo-controlled, randomized clinical study, the cardioprotective effect of nifedipine (Adalat, Bayer) as an adjunct to St. Thomas' cardioplegia was investigated in 24 patients undergoing coronary artery bypass grafting. Nifedipine at a dosage of 200 micrograms or placebo was added to each 1000 ml of St. Thomas solution, under strict light protection. ECG and haemodynamic data, including cardiac output measurements, serum calcium levels, creatine phosphokinase, (CK) CK-MB and lactate were measured during and after the operation. Additional cardioprotective effects were demonstrated in the nifedipine group by a significantly lesser reduction of the cardiac index after cardiopulmonary bypass and lower post-operative CK and CK-MB serum levels (P < 0.05). The incidence of ischaemia and cardiac arrhythmias was significantly higher in the placebo group on the post-operative ECG.

Arrhythmias, Cardiac↗
PubMed1993

Improved cardiac performance and reduced pulmonary vascular constriction by epinephrine administration via a left atrial catheter in cardiac surgical patients.

Diminished left ventricular contractility and increased right ventricular afterload are issues in cardiac surgery. The usual administration of catecholamines (epinephrine) via the central venous (CV) catheter increases cardiac output, but also may increase pulmonary vascular constriction. Epinephrine was, therefore, administered via the left atrial (LA) catheter or the CV catheter in 8 cardiac surgery patients, each serving as his or her own control. The LA administration of epinephrine has an advantage with its immediate effect on the coronary circulation, while avoiding associated pulmonary vasoconstriction by passing through the systemic capillary bed before reaching the lung. It was found in this study that administration of epinephrine via an LA catheter increased the average cardiac output by 1.05 L/min, which was significantly (P < 0.05) greater than with administration via the CV catheter. With LA administration of epinephrine, systemic arterial pressure (systolic arterial pressure and diastolic arterial pressure) (SAP, DAP) were also elevated to a greater extent than by CV administration. On the other hand, pulmonary arterial pressures (systolic pulmonary arterial pressure and diastolic pulmonary arterial pressure) (SPAP, DPAP) were less elevated than by administration via the CV catheter. This produced increased coronary perfusion and a smaller increase in pulmonary vascular tone by LA administration in contrast to CV administration of epinephrine. It is concluded that epinephrine administration via an LA catheter improved myocardial performance and pulmonary perfusion due to direct entry of the agent into the coronary circulation and partial metabolism while passing through the systemic capillary bed before reaching the lung.

Blood Pressure↗
PubMed1993

Arterial to end-tidal CO2 tension difference after bilateral lung transplantation.

OBJECTIVES: To assess ventilation/perfusion mismatch with high ventilation/perfusion ratios (i.e., alveolar deadspace) and to assess capnography as a noninvasive method of monitoring ventilation after bilateral lung transplantation. DESIGN: Clinical, prospective study. Repeated-measures analysis of variance was done to assess the time course of the arterial to end-tidal CO2 tension difference. SETTING: University hospital operating theater and intensive care unit. PATIENTS: Seven consecutive patients aged 25 to 64 yrs who underwent bilateral lung transplantation for end-stage lung disease. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The arterial to end-tidal CO2 tension difference was determined using infrared absorption capnography during postoperative day 1. Measurements were done at 10 mins, and at 1, 3, 12, and 24 hrs after bilateral lung transplantation (timing of measurements determined from the time when both lungs were perfused and mechanically ventilated). An arterial to end-tidal CO2 tension difference, ranging from 6 to 21 torr (0.8 to 2.8 kPa), mean 16 +/- 5 torr (2.2 +/- 0.7 kPa), was observed immediately after the transplantation. This difference rapidly decreased to 9 +/- 4 torr (1.2 +/- 0.6 kPa; p < .01) after 3 hrs and to 5 +/- 3 torr (0.6 +/- 0.4 kPa; p < .01) after 24 hrs. CONCLUSIONS: Our data suggest marked alveolar deadspace ventilation immediately after bilateral lung transplantation. The presence and rapid improvement of this ventilation/perfusion mismatch may reflect the presence of ischemia-reperfusion lung injury and its improvement in the first hours of reperfusion. In five of seven patients, capnography was not a good measure of PaCO2 during the first hours after bilateral lung transplantation.

Adult↗
PubMed1990

[Myocardial metabolism during the pre-ischemic administration of metabolic myocardial protection in coronary surgical patients].

Metabolic myocardial preservation by means of preischemic insulin administration (glucose-potassium-insulin, GPI; acute parenteral alimentation, APA) with the aim of a preischemic myocardial glycogen enrichment was performed in 20 consecutive CABG patients (12 in the APA group, 8 in the control group). Before and after 30 min of an infusion (APA or 0.9% NaCl solution), blood levels of potassium, glucose, NEFA (non-esterified fatty acids) and lactate were determined from arterial (a), central venous (cv) and coronary sinus (cs) blood. The cs potassium level in the APA group decreased from 4.06 to 3.56 mmol/l, whereas in the control group an increase from 3.78 to 4.36 mmol/l occurred. The difference between the two groups (interaction) was significant, p less than 0.002. The myocardial glucose extraction (a-cs difference) in the APA group increased from 3.83 to 10.08 mg/dl, whereas in the control group a change from 3.37 to 0.87 mg/dl occurred (p less than 0.0003). The myocardial NEFA (non-esterified fatty acids) extraction in the APA group decreased from 0.25 to -0.06 mmol/l, whereas in the control group no change (0.08 to 0.13 mmol/l) occurred (p less than 0.05). The myocardial lactate extraction in the APA group increased from 0.13 to 0.70 mmol/l, whereas in the control group no change occurred (0.47 to 0.51 mmol/l), interaction p less than 0.0001. It is concluded that a preischemic insulin administration (APA) for metabolic preservation leads to: (1) myocardial potassium extraction, obviously caused by intracellular potassium shifting; (2) increased myocardial glucose extraction; (3) decreased myocardial NEFA extraction, the last two obviously caused by a shift of the myocardial metabolism from predominant lipolysis to predominantly glycolysis; and (4) surprisingly, increased myocardial lactate extraction (decreased lactate production), obviously caused by the avoidance of a myocardial lactate accumulation by way of stimulated pyruvate oxidation. Increased anaerobically, available ATP without myocardial lactate production must be considered a metabolic contribution to myocardial protection against ischemic damage.

Adult↗
PubMed1985

[Intraoperative changes in extravascular lung water. Study on heart surgery patients].

The intraoperative changes in extravascular lung water (EVLW) were studied in 40 patients undergoing aortic-coronary bypass grafting. The patients were divided into two groups on the basis of preoperative ejection fraction (EF) values (group I: EF greater than 45%; group II: EF less than 45%). EVLW was measured using the double-indicator dilution method (thermo/dye). In a control study, changes in transthoracic impedance (ZoTh) were recorded. The initial EVLW value in group I was 4.3 +/- 0.4 ml/kg body wt. and in group II, 4.4 +/- 0.3 ml/kg body wt. After extracorporeal circulation, significant changes in EVLW could be observed (group I: from 4.5 +/- 0.5 ml/kg body wt. to 7.0 +/- 0.2 ml/kg body wt.; group II: from 5.1 +/- 0.8 ml/kg body wt. to 7.8 +/- 0.9 ml/kg body wt. (p less than 0.001). At the end of the operation, no changes in EVLW were observed in group I. However, in group II EVLW was significantly different to initial values (6.3 +/- 1.0 ml/kg body wt., p less than 0.01). The results obtained using the double-indicator method were identical with those obtained using the transthoracic impedance method. A marked correlation could be seen between length of ECC recording and EVLW values at the end of the operation, especially when the ECC time was 90 min or more (r = 0.84). Based on our results, it must be assumed that intraoperative damage to capillary membranes occurs if the ECC time is above 90 min.

Coronary Artery Bypass↗
PubMed1984

Preventive insulin administration for myocardial protection in cardiac surgery.

The object of this study was to determine whether high doses of insulin administered preventively in combination with glucose and potassium exert a protective effect upon the myocardium. This approach should result in a preoperative accumulation of the myocardial glycogen stores with an increased anaerobic provision of energy-rich substrates (ATP) during coronary ischemia. Two comparable groups of seven dogs each, undergoing experimental extracorporeal circulation (ECC) with 90-min aortic cross-clamping were examined. Cardiac output (CO), systolic left ventricular blood pressure (pventr), left ventricular enddiastolic pressure (LVEDP), mean central venous pressure (CVP), and heart rate (HR) were recorded at left atrial (LA) pressures of 5, 10, 15, and 20 mmHg in order to construct ventricular function curves. These data were registered prior to the onset of ECC (preischemic value), after termination of ECC and after two 10-min periods of reperfusion. The first group served as control and the second group received high iv doses of insulin (total 25 U/kg) within 60 min prior to the onset of the ECC. In the control group, pventr and CO after termination of the ECC and after the first reperfusion were significantly (P less than 0.05) less than the preischemic values; after the second reperfusion they reached the preischemic range. In contrast, pventr and CO in the insulin group already were within the preischemic range at the termination of the ECC. After the first and the second reperfusion, CO was even greater than the preischemic value. LVEDP changed inversely, while CVP and HR showed no significant differences.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Haemodynamic effects of fentanyl or alfentanil as adjuvants to etomidate for induction of anaesthesia in cardiac patients.

This investigation was designed to study the comparative haemodynamic effects of alfentanil, 5 mg vs. fentanyl 0.5 mg when administered in combination with etomidate for induction of anaesthesia in patients undergoing cardiac surgery. Both groups manifested significant decreases in heart rate (17-22%), cardiac index (12-25%) and mean pulmonary artery pressure (4-17%). The mean arterial pressure was decreased in both groups; however, the decrease was significantly greater in the alfentanil group. In contrast to the fentanyl group, the systemic vascular resistance was transiently decreased in in the alfentanil group. In conclusion, it appears that alfentanil is associated with a greater degree of cardiovascular depression than fentanyl when used in combination with etomidate as part of an induction sequence in cardiac surgery patients.

Adjuvants, Anesthesia↗
PubMed1984

Improvement of cardiac preservation by preoperative high insulin supply.

Therapeutic administration of high doses of insulin achieves a shifting of metabolism to glycogenesis and glycolysis. The result is an accumulation of the myocardial glycogen stores and an improvement of glucose utilization as well. If on that basis an increased anaerobic provision of adenosine triphosphate will be maintained in the myocardium during ischemia, the myocardial cell viability during aortic cross-clamping will be saved as well. Thus a preventive insulin supply will preserve the heart from ischemic damage. Twenty patients undergoing mitral valve replacement were investigated in two randomized groups. One group received insulin (1 U/kg/hr) together with a 33% glucose infusion (0.5 gm/kg/h) and potassium (0.25 mEq/kg/hr) from the onset of anesthesia until aortic cross-clamping. The control group received Ringer's lactate at the same infusion rate. After an average ischemic time of 26 minutes, an excised papillary muscle tip was immediately plunged into liquid nitrogen and the content of adenosine triphosphate, adenosine diphosphate, and creatine phosphate was determined. The adenosine triphosphate/diphosphate quotient and the energy charge potential were calculated. The mean adenosine triphosphate content in the insulin group was 7.43 mumol/gm wet weight and was significantly (p less than 0.01) higher than that of the control group (4.28 mumol/gm). The mean ADP content was 1.43 mumol/gm in the insulin group versus 1.81 mumol/gm in the control group. The mean creatine phosphate content was again significantly (p less than 0.05) higher in the insulin group (6.70 mumol/gm) than in the control group (5.30 mumol/gm). Also, the mean adenosine triphosphate/diphosphate quotient (insulin group, 5.19; control group, 2.36) and the mean energy charge potential (insulin group, 0.919; control group, 0.851) were significantly (p less than 0.01) higher in the insulin group. It is concluded that the preventive application of high doses of insulin leads to an augmented myocardial adenosine triphosphate provision and a maintained cellular energy charge during coronary ischemia. As a result, ischemic tolerance is enhanced and myocardial protection is improved.

Adenine Nucleotides↗
PubMed1982

[Postoperative arrhythmias in heart surgery].

After a brief comment on the origin and a summing up of types of postoperative cardiac arrhythmias in open heart surgery, mainly the therapy of these arrhythmias is discussed Besides drug therapy (antiarrhythmica) and cardioversion resp. pacing especially the possibility of a metabolic therapy is presented. In the postoperative phase after the trauma by the operation with the heart lung machine - which is similar to the shock phase after a myocardial infarction - a disordered energy metabolism with a decreased effectiveness of insulin occurs. It exists a diminished intracellular potassium-shifting, which causes an insufficient myocardial cell membrane potential. By means of exogenous high insulin and potassium supply with glucose infusion the potassium-shifting is improved, the FFA-level is lowered and the incidence of arrhythmias is reduced as sinusrhythm is induced.

Anti-Arrhythmia Agents↗
PubMed1982

[Improved myocardial protection in open heart surgery by massive preoperative insulin supply (author's transl)].

In this study we investigated, whether in addition to cooling and cardioplegia, preventive administration of massive doses of insulin with glucose exerts a protective effect on the myocardium by increasing myocardial glycogen stores and shifting myocardial metabolism towards (primarily anaerobic) glycolysis. Experiments were done on two groups of 5 dogs each (average 27 kg) undergoing experimental extracorporeal circulation (ECC) with 90 min aortic clamping, under cooling and cardioplegia. Cardiac output (CO), systolic ventricular blood pressure (Pventr), heart rate (HR) and mean central venous pressure (CVP) were recorded at LA-levels of 5, 10, 15 and 20 mm Hg before onset of ECC (preop. value), after termination of ECC, and after 2 periods of a 10 min. reperfusion. While the 1st group served as control, the 2nd group received a massive i.v. insulin supply (total 20 U/kg) every 10 min, as well as glucose to keep blood sugar level stable within 60 min. prior to the onset of ECC. It was shown that in the control group after termination of ECC and after 1st reperfusion Pventr and CO were significantly below the preop. values, and only after the 2nd reperfusion within the preop. range. In the insulin group, however, Pventr and CO were already within the preop. range at termination of the ECC. After the 1st and after the 2nd reperfusion CO was in part significantly above the preoperative value. HR and total peripheral resistance (TPR) were not significantly changed. It is concluded that preventive insulin application produces a more vital myocardial cell function immediately after termination of ECC, indicating increased myocardial protection and improved ischaemic tolerance.

Animals↗
PubMed1981

[Metabolism during shock and its therapeutic regulations].

During shock the organism reacts by means of primarily useful autoregulation mechanisms which, however, in excess become useless and at least harmful. Therapeutically it is necessary now, to partly break through these mechanisms going along with substitution of certain necessary substances and besides that in part to support the organism's own concept.

Animals↗
PubMed1981

[Postoperative therapy by means of acute parenteral alimentation (APA) with high doses of insulin and glucose after open heart surgery (author's transl)].

Immediately after open heart operations (extracorporeal circulation) 22 patients were investigated in 2 groups at the intensive care unit. Whereas the control group received Ringer lactate as postoperative infusion (RL-group), the 2nd group was given 50% glucose (0.5 g/kg/h) and insulin (250 U/1,000 cc) (GI-group). In case of need (blood glucose level) additional insulin up to 200 U/h, maximum 800 U/10 h, was supplied. On the 1st postoperative day 500 ml 10% crystalline amino acid solution was added. Before the start of postoperative infusion therapy postoperative serum insulin levels were low in spite of considerably elevated blood glucose levels (glucose utilisation disorder, insulin suppression). In contrast with the RL-group there was in the GI-group a significant decrease of FFA-serum level and cAMP serum level which developed during the infusion. Urine output and urinary glucose excretion was nearly equal in both groups. Urinary potassium excretion in the GI-group remained significantly one third lower than that of the RL-group, in spite of the potassium supply to the GI-group being nearly twice and serum potassium level approximately equal. Urinary sodium excretion of GI-group on the other hand was approximately 15% higher than that of RL-group. In relation to preoperative values postoperative urinary N-excretion of the GI-group was unchanged, whereas in RL-group the postoperative N-excretion was significantly 30% increased; in postoperative alpha-amino-N-excretion there was only a small difference between the groups, which indicates an insulin-modifiable increase in protein breakdown rather than a decreased protein synthesis. According to the obviously improved situation in energetic considerations, cell membrane potential restoration and N-balance resp. protein synthesis in the insulin treated group, the question is discussed whether this therapy (APA) which shifts metabolism to an anabolic state, is of a certain value as a therapeutic measure in the postshock phase.

Adult↗