Carnitine metabolism in Macaca arctoides: the effects of dietary change and fasting on serum triglycerides, unesterified carnitine, esterified (acyl) carnitine, and beta-hydroxybutyrate.

Serum triglycerides and serum total, esterified, and free (unesterified) carnitine were measured in 21 male Macaca arctoides that were switched from a low fat (5.2% w/w), high carbohydrate diet to a high fat (15.9% w/w), low carbohydrate diet for 90 days and then returned to the original low fat diet for a subsequent 76-day period. Serum triglycerides and total carnitine levels fell significantly (p less than 0.05) during the initial 2 wk of feeding the high fat diet and the ratio of esterified/unesterified carnitine rose significantly (P less than 0.05) on the high fat diet. A return to the low fat diet reversed these changes; triglycerides rose significantly (p less than 0.05) within 3 days and the ratio of esterified/unesterified carnitine fell significantly (p less than 0.05) within 3 days and the ratio of esterified/unesterified carnitine fell significantly (p less than 0.05) during the same period. A return of total carnitine levels to those initially observed on the low fat diet was slower to develop. Fasting for 24 to 48 h resulted in increases of 65 to 75% in total serum carnitine. This increase reflected elevations of both the esterified and unesterified carnitine fractions but was largely attributable to increases in esterified carnitine which rose from 10 to 41 nmol/ml by 48 h while unesterified carnitine rose from 55 to 72 nmol/ml during the same period. In addition, the ratio of esterified/unesterified carnitine ratio rose from 0.183 +/- 0.023 to 0.583 +/- 0.069 (n = 8) with a 48-h fast and was significantly correlated with serum beta-hydroxybutyrate levels at both 24 and 48 h.

Failure of chronic cigarette smoke exposure to alter plasma lipoproteins of stumptailed macaques (Macaca arctoides).

Twenty-one 8-14 kg adult male stumptailed macaques, Macaca arctoides, were fed a standard laboratory diet and divided into 3 groups. The high-dose group and low-dose group were exposed to cigarette smoke at the human equivalent of 3 packs and 1 pack per day, respectively, 7 days per week, for 3-5 years. Eight animals served as cage an sham controls. Peak blood carboxyhemoglobin (COHb) levels measured immediately after smoking showed levels of 0.5+/- 0.1%, 3.6+/-1.0%, and 5.7+/-2.8% for sham controls, low, and high dose smokers, respectively. Hemoglobin and hematocrit values were 2-7% higher (N.S. to P less than 0.05) for smoking groups, presumably as a consequence of chronically elevated COHb levels. No significant differences were seen in total plasma cholesterol and lipoprotein cholesterol concentration measured at four intervals over period of one year. We conclude from these data that, while fed a low fat diet, chronic cigarette smoke inhalation fails to alter plasma lipoprotein levels in this animal model.

Glutathione status of isolated rabbit lungs. Effects of nitrofurantoin and paraquat perfusion with normoxic and hyperoxic ventilation.

Thirty-minute perfusion of isolated rabbit lungs with a Krebs-Ringer bicarbonate buffer containing 420 microM paraquat (PQ) or nitrofurantoin (NF) resulted in increases in lung oxidized glutathione (GSSG) content of 589 and 2656%, respectively, over control levels. The degree of glutathione efflux was also increased with both agents, i.e. 77 and 238% above control leakage for PQ and NF respectively. The pulmonary toxicity of both compounds is known to be heightened by conditions of hyperoxia(O2). Ventilation of lungs with 95% O2-5% CO2 did not, in itself, significantly alter glutathione efflux, GSH or GSSG levels. However, ventilation with 95% O2-5% CO2 increased lung GSSG levels in PQ-perfused lungs 225% over PQ-air-perfused lungs, a combined effect not observed with NF-O2, wherein mean GSSG levels were only 72% of that observed with NF-air. Glutathione efflux in PQ-O2-treated lungs declined somewhat (20%) compared to that observed with PQ-air, but a significant increase in the amount of glutathione efflux was seen with NF-O2-treated lungs, i.e. 120 and 310%, respectively, over that attributable to NF or O2 alone. Although the biochemical mechanisms of toxicity of these compounds are thought to be very similar, the disparate degree of GSH oxidation observed with equimolar levels of PQ and NF may indicate differences in reactivity towards glutathione and other lung sulfhydryl pools. The stimulation of the oxidative effects of PQ and NF on lung GSH due to hyperoxic ventilation may be related to the reported O2 enhancement of their toxicity.

Prophylactic antibiotics in noncardiac thoracic operations.

A high incidence of thoracotomy wound infection and empyema in 1972 was associated with inadequate and irregular administration of prophylactic antibiotics. Beginning with 1973, a strict regimen was adopted that combined systemic cephalosporins and two topical antibiotics (cephalothin and kanamycin). Emphasis was placed on preoperative administration of the systemic agent and on use of the topical drugs before the operative field was contaminated. The patient groups for 1972 and 1973 were similar in most respects, but the wound complication rate was 18.4% in 1972 and 4.8% in 1973.

Pleural flap closure of pericardial defects following intrapericardial pneumonectomy.

Persistent pericardial defects following intrapericardial pneumonectomy are, historically, the major cause of iatrogenic cardiac herniation. This complication is uniformly fatal when unrecognized and untreated and has been associated with a 43% mortality even with surgical correction. Suture approximation of all small defects is recommended, and a technique for routine pleural flap closure of moderate to large-sized defects is described.

Evaluation of tracheal incisions for tracheostomy.

Three standard tracheostomy incisions in dogs were compared to determine whether any were more likely associated with stomal stenosis. Each incision resulted in an average reduction in tracheal lumen of 25 per cent, with a 50 per cent maximum. The incision selected should depend on the conditions present.

Preservation of an infected arterial graft with combination systemic-topical antibiotic therapy.

A case is presented which illustrates the unusual ability to retain a bifurcation aortofemoral vascular graft with the graft-to-femoral-artery anastomosis involved in a groin abscess. The drainage of the abscess, debridement of devitalized tissue, and the combined application of topical and systemic antibiotic therapy was successful. Some authors report that should an anastomosis of a bifurcation vascular graft, in the vicinity of the groin, become involved in infection, the threat of anastomotic disruption and continued sepsis may lead to amputation, death, or both. It is not the purpose of this report to advocate conservative management of a vascular graft infection with suture line involvement based on anecdotal experience. However, the case reported here and the experience of other authors mentioned suggest that an attempt to treat an infected graft without its removal may be indicated in selected patients where extra anatomical revascularization would be hazardous.

A proposed technique for treatment of hypoplastic left heart syndrome.

The Hypoplastic Left Heart Syndrome includes a variety of anomalies, all characterized by a hypoplastic or absent left ventricle. A technique is described for producing a normal course of circulation in these cases. Its ultimate success will depend on the patients having a low pulmonary vascular resistence.