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Biomedical subjects

M D Klein

Publications and source records attributed to M D Klein.

At least 91 records · Page 5Linked to original sources

Coronary artery bypass surgery. Physical, psychological, social, and economic outcomes six months later.

To evaluate the benefits of coronary artery bypass graft (CABG) surgery, we interviewed and tested 318 patients (268 men and 50 women) younger than age 70 before and six months after elective CABG at four university medical centers. Biomedical, psychoneurological, physical function, role function, occupational, social, family, sexual, emotional, and attitudinal variables were assessed. Quantitative comparisons showed improvement on many factors. Angina was completely relieved for 69% to 85% of persons, depending on whether it had been induced by exertion or other events. Disability days were reduced more than 80%. Seventy-five percent of employed persons had returned to work. Anxiety, depression, fatigue, and sleep problems declined. Vigor and well-being scores rose significantly. When losses were expected (eg, psychoneurological function, marital adjustment), they generally were not found. For none of the more than 60 outcome variables was widespread serious worsening found. The findings suggest that the great majority of patients are able to resume normal economic and social functioning within six months after CABG.

Adult↗

Efficacy and safety of verapamil in patients with angina pectoris after 1 year of continuous, high-dose therapy.

The long-term efficacy and safety of high-dose verapamil therapy (480 mg/day) was assessed in 26 patients with chronic stable angina pectoris during a 3-phase protocol: Phase 1--an initial, 6-week placebo-controlled, double-blind crossover assessment; Phase 2--an open label, 1-year follow-up; and Phase 3--a final drug withdrawal and rechallenge 10-week study. Three patients withdrew during Phase 2 (1 had hepatitis and 2 underwent coronary bypass surgery). Adverse effects during Phase 2 were mild, consisting of constipation (6 patients) and prolongation of the P-R interval (5 patients); however, no patient required alteration of the 480 mg/day dosage. At the end of Phase 2, 10 patients underwent the Phase 3 study, commencing with a 2-week period in which verapamil was either tapered gradually or abruptly discontinued. This was followed by an 8-week double-blind, placebo-controlled crossover rechallenge study with verapamil. The clinical and exercise responses to verapamil compared with placebo were similar during the Phase 3 protocol and the initial Phase 1 study (treadmill time increased by 55% and anginal attacks per week decreased by 63% during Phase 3, compared with a 28% increase and a 42% decrease, respectively, during Phase 1, p = not significant [NS]). Withdrawal of verapamil produced a similar return of anginal symptoms whether the drug was abruptly discontinued or its administration tapered. No patient had unstable angina pectoris or acute myocardial infarction. These investigations demonstrate that verapamil is safe and effective when evaluated after 1 year of continuous therapy using a dosage of 480 mg/day. There is no evidence of drug tachyphylaxis, nor does verapamil appear to cause an abrupt withdrawal syndrome in patients with chronic stable angina pectoris.

Adult↗

The quantitative transperitoneal absorption of a fat emulsion: implications for intraperitoneal nutrition.

Intraperitoneal (IP) administration of nutrients would be an attractive alternative to intravenous nutrition since it eliminates intravascular complications. If glucose alone were used as the nonprotein calorie source, associated fluid shifts might not be well tolerated by the patient. A fat emulsion does not have osmotic properties and thus might be incorporated into a program of IP nutrition as a calorie source. Transperitoneal absorption of a commercial fat emulsion (Liposyn 10%, Abbott Laboratories, N Chicago, IL) was studied in 12 beagle puppies divided into two groups. One group received 2.5 gm/kg of fat and the other group received a similar volume of 3.5% crystalline amino acids and 5% glucose in one IP dose. In the first group, the serum triglyceride (TG) increased three fold from 61 +/- 25 mg% to 185 +/- 61 mg% at 15 minutes and then decreased slowly while remaining significantly elevated (p less than 0.05) at 4 hours. 1.94 +/- 0.20 gm/kg of TG were absorbed from the peritoneal cavity over 4 hours. Concommitant IP administration of amino acids and glucose did not affect that absorption. Radiolabeled amino acids and glucose instilled IP were demonstrated in the blood immediately after administration and their absorption was not affected by the presence of a fat emulsion. Plasma free fatty acids showed a small increase at 4 hours (from 0.32 +/- 0.09 mEq/L to 0.59 +/- 0.22 mEq/L). Animals receiving no IP fat showed no change in serum TG. Serum glucose rose in both groups and serum cholesterol showed no changes in either group. Peritoneal fluid accumulation 4 hours after IP fat administration was minimal at 12.7 +/- 6.4 mL/kg. This study shows that a fat emulsion can be quantitatively absorbed from the peritoneal cavity over four hours and that IP nutrition may be feasible.

Absorption↗

Venovenous extracorporeal membrane oxygenation in neonates with respiratory failure.

Venoarterial (VA) extracorporeal membrane oxygenation (ECMO) has been successful in support of neonates with respiratory failure but requires right common carotid artery ligation. While no short-term neurologic complications have resulted from neonatal carotid ligation, late complications may occur. For both VA ECMO and venovenous (VV) ECMO, blood is drained from the right atrium via a right internal jugular cannula, oxygenated by a membrane lung, and returned to the patient. VV ECMO spares the carotid by perfusing the oxygenated blood into a vein. VV ECMO gave total respiratory support to three neonates with respiratory failure and each infant survived. In comparison with three similar VA ECMO patients, the VV patients required higher ECMO circuit flow rates and had lower systemic arterial Po2s. Length of time on ECMO, length of hospital stay, and neurologic outcome were similar in the VV and VA patients. Differences among the patients were related to their primary disease rather than to the mode of ECMO support. The VV patients had cannulation of the femoral vein for perfusion of oxygenated blood. Late complications may occur from femoral vein ligation as well as from carotid ligation so long-term follow-up is needed to assess these two ECMO techniques.

Female↗

Cervical teratomas in the newborn.

Cervical teratomas are rare neoplasms which have been infrequently reported. During the period of July 1974 to April 1982, six newborns with this lesion were seen at the Mott Children's Hospital. There were three males and three females, all of whom presented at birth with large semicystic neck masses. In four infants, calcifications were seen on x-ray. Four patients required intubation within the first hours of life for respiratory distress. One child of 33 weeks gestation expired prior to operation because of a hypoplastic left ventricle and bilateral hypoplastic lungs. Cord blood T3 and T4 values were normal in three patients; the TSH was elevated 1.5 and 2 times normal in two of these infants. Four neonates were operated upon within 24 hours of birth and suffered no postoperative complications. One baby presented on the third day of life and expired three hours postoperatively from persistent respiratory distress. The tumors were well encapsulated and arose from or were surrounded by a lobe of the thyroid gland. In each case, the tumor was removed by performing a total thyroid lobectomy. The presence of normal thyroid tissue at the resection margin (in the isthmus) was verified by frozen section. One patient presented with cervical node metastases but is currently free of disease one year postoperatively. These six cases bring the total reported cases in the literature to 136. The 80% mortality in cases not operated upon has been reduced to 15% by prompt operation. This series substantiates the significant respiratory distress that can occur in newborns with cervical teratomas and confirms the need for emergency surgery in this group of patients.

Diseases in Twins↗

The surgical management of terminal ileal and right colon Crohn's disease in children.

During a recent 7-year period, 11 children between the ages of 6 and 15 years underwent intestinal resection for terminal ileal and right colon Crohn's disease. The indications for surgery included: failure of medical therapy in 8 patients, growth retardation in 4, stricture formation in 5, abscess formation in 2, the presence of an enterocutaneous fistula in 2, and intestinal obstruction in 1. All children underwent resection of the grossly involved bowel. The sites of involvement were the terminal ileum and the ileocecal valve in 7 patients and the terminal ileum, cecum, and proximal right colon in 4. There were no postoperative complications or mortality. The follow-up in these patients ranged from 1 to 7 years with a mean of 2.6 years. Thus far, all patients are clinically well and off all medications. Only one questionable recurrence was seen in a teenage girl who was readmitted 3 years after a resection of her terminal ileum and cecum for Crohn's disease. A recent small-bowel series 4 years after the recurrence shows no evidence of Crohn's disease. The initial excellent results with resectional therapy in this small subgroup of children with Crohn's disease has prompted us to consider earlier surgical intervention in these patients.

Adolescent↗

Efficacy and safety of incremental doses of diltiazem for the treatment of stable angina pectoris.

The safety and efficacy of incremental doses of diltiazem in treating angina pectoris were assessed in 20 patients with functional class II to III exertional angina. During an initial single-blind dose titration phase, dilitiazem produced a dose-related improvement in anginal frequency and exercise capacity. Weekly anginal attacks were reduced to 7.5 +/- 8.9, 5.6 +/- 7.8 and 4.9 +/- 7.3 on diltiazem, 120, 240 and 360 mg per day, respectively, as compared with 11.9 +/- 8.7 on placebo (all p less than 0.001). Treadmill time was significantly enhanced by high dose (360 mg per day) as compared with moderate dose (240 mg per day) diltiazem: 473 +/- 149 versus 424 +/- 146 seconds (p less than 0.05). Time to ischemic ST segment depression was similarly changed: 344 +/- 132 versus 298 +/- 142 seconds (p less than 0.05) by high dose as compared with moderate dose diltiazem. During a subsequent double-blind phase, high dose diltiazem significantly reduced weekly anginal frequency when compared with placebo: 3.1 +/- 3.0 versus 9.3 +/- 7.1 (p less than 0.001); and increased treadmill exercise time: 508 +/- 158 versus 418 +/- 172 seconds on placebo (p less than 0.05). Subjective and objective benefits of high dose diltiazem were sustained during a follow-up period of 6 months without major drug side effects.

Adult↗

A home-centered instructional communication strategy for severely handicapped children.

Family involvement is an essential element of language intervention with severely handicapped children for several reasons. First, the parent-child interaction is the focus of normal language development, and can be a powerful impetus in language learning for handicapped children. Second, limited generalization and maintenance of skills often occur when they are acquired in environments that do not also teach the appropriate use of skills. Third, parents can be successful intervention agents and may generalize their skills to other interactions with their child. Training conducted in the home must be compatible with that environment: it should involve only those skills that are of immediate use in the home. The Instructional Communication Strategy described herein represents such a program. It is a synthesis of training strategies used with normal and handicapped children, and is applicable regardless of child's level of functioning, age, or handicapping condition. This training model involves considerable modification in the role of speech-language pathologists dealing with the severely handicapped. The professional's skills are best utilized for assessment, program development, monitoring progress, and training specialized skills. The parents provide most of the direct training; however, professionals are also utilized for the child's maximum benefit.

Child↗

Correlates of angina pectoris among men awaiting coronary by-pass surgery.

Biomedical, behavioral, and psychological correlates of angina pectoris were identified in 204 men awaiting coronary artery by-pass graft surgery. Angina was rated by use of a precoded series of interview questions. Four circumstances of anginal symptoms were investigated: exertional, emotional, post-prandial, and while resting or sleeping. These were uncorrelated with one another, except for exertional and post-prandial. Two-thirds of these patients experienced angina less often than daily in the most recent unrestricted month. Severity of coronary artery obstruction was not positively associated with frequency or severity of any type of angina, and were primarily behavioral and psychological. Disturbances of sleep, physical inactivity, history of cigarette smoking, distressed response to life crises, life dissatisfactions, hostility, use of propranolol, duration of cardiac illness, and age were among the predictors in the multiple regression equations. These results from selected by-pass candidates may apply more directly to such persons than to unselected community residents reporting angina symptoms. The findings suggest the need for greater focus on sources of variability in myocardial oxygen supply and demand in understanding the dynamics of angina episodes.

Adult↗

Physical, psychologic, social, and economic outcomes after cardiac valve surgery.

Eighty-nine patients receiving cardiac valve replacement or surgery consisting of valve replacement and coronary artery bypass grafts in four teaching hospitals were studied before surgery and again six months after surgery. More than 60 indicators of the quality of life were assessed. The majority of persons showed improvement in physical function, emotional states, and social activity. Of those with exertional angina or dyspnea before surgery, about two thirds were completely relieved at six months after surgery. There was a substantial reduction in number (from 31 to seven) of persons with five or more days of disability per month due to cardiac symptoms. The majority remained the same in their usual level of physical activity, most psychological traits, and attitudes and social support networks. Most previously employed persons returned to work. Improvements in the conditions of patients who had valve surgery closely paralleled those of patients who had undergone coronary artery bypass surgery in the same hospitals.

Activities of Daily Living↗

Heparinase: in vivo activity and immunogenicity in rabbits.

Anticoagulation with heparin is required during extracorporeal circulation for hemodialysis and cardiopulmonary bypass as well as during vascular surgery. Reversal of anticoagulation with protamine may be associated with hypotension and rebound anticoagulation and requires stoichiometric doses. Heparinase from Flavobacterium heparinum catalytically degrades heparin and reverses its anticoagulant effect. Heparin was administered to New Zealand White rabbits and plasma levels were assayed with the APTT anticoagulant assay and the azure A chemical assay. Heparinase actively degraded heparin both in vitro in rabbit plasma and in vivo in rabbit blood as determined by both the anticoagulant and chemical assays when compared to control heparin disappearance curves. Antibodies to heparinase were demonstrated by the ELISA technique in rabbits receiving i.v. heparinase. These antibodies, however, did not effect the activity of the enzyme in vitro or in vivo. No toxic effects of heparinase were noted in observations of the animals or in blood and histologic studies. Heparinase, either free or immobilized, may be a useful heparin-reversing agent without the drawbacks of protamine.

Animals↗

Verapamil therapy for stable exertional angina pectoris.

Clinical and exercise responses to therapy with the calcium-channel blocking agent verapamil were assessed in 26 patients with stable exertional angina pectoris using a double-blind, placebo-controlled, randomized crossover study design. Verapamil, 480 mg daily, reduced the frequency of angina attacks (5.6 +/- 7.3 to 2.2 +/- 3.0 attacks per week, p less than 0.001) and number of nitroglycerin tablets consumed (3.4 +/- 4.9 to 1.2 +/- 2.5 tablets per week, p less than 0.05), and increased exercise duration (6.4 +/- 2.1 to 7.5 to 1.8 minutes, p less than 0.001) (all data are mean +/- standard deviation). These changes were significantly better than those seen with placebo. These beneficial effects of verapamil were related to significant reduction in the heart rate-systolic blood pressure product during submaximal exercise. Adverse effects from verapamil were few and consisted primarily of constipation in 6 patients. A total of 193 patients had been entered in 6 independent clinical trials, which have compared verapamil with placebo for the treatment of stable exertional angina pectoris, using a similar study design. The combined evidence from all these studies indicates that verapamil is a highly effective and safe drug for the treatment of stable effort-related angina pectoris.

Adult↗

Peripheral arterial and venous responses to acetylstrophanthidin in patients with acute myocardial infarction.

The peripheral arterial and venous responses to rapidly active acetylstrophanthidin (rather than the much slower digitalis) were studied in patients with acute myocardial infarction without congestive heart failure. In eight control patients placebo did not change mean blood pressure (BP), calf blood flow (CBF), calf vascular resistance (CVR), or calf venous volume (CVV). Seventeen patients received 10 mg IV acetylstrophanthidin. In these patients BP increased 5.3%, CBF decreased 18.2%, and CVR increased 29.2%. Venous capacitance was not changed. Acetylstrophanthidin induced no significant change in cardiac output, systemic vascular, resistance, pulmonary capillary wedge pressure, or right atrial pressure. In patients with acute myocardial infarction not complicated by congestive heart failure, digitalis may promote limb vasoconstriction and increase blood pressure, but it does not adversely affect cardiac function.

Electrocardiography↗