Cloning, nucleotide sequencing, and expression of the Clostridium perfringens enterotoxin gene in Escherichia coli.

A complete copy of the gene (cpe) encoding Clostridium perfringens enterotoxin (CPE), an important virulence factor involved in C. perfringens food poisoning and other gastrointestinal illnesses, has been cloned, sequenced, and expressed in Escherichia coli. The cpe gene was shown to encode a 319-amino-acid polypeptide with a deduced molecular weight of 35,317. There was no consensus sequence for a typical signal peptide present in the 5' region of cpe. Cell lysates from recombinant cpe-positive E. coli were shown by quantitative immunoblot analysis to contain moderate amounts of CPE, and this recombinant CPE was equal to native CPE in cytotoxicity for mammalian Vero cells. CPE expression in recombinant E. coli appeared to be largely driven from a clostridial promoter. Immunoblot analysis also demonstrated very low levels of CPE in vegetative cell lysates of enterotoxin-positive C. perfringens. However, when the same C. perfringens strain was induced to sporulate, much stronger CPE expression was detected in these sporulating cells than in either vegetative C. perfringens cells or recombinant E. coli. Collectively, these results strongly suggest that sporulation is not essential for cpe expression, but sporulation does facilitate high-level cpe expression.     

A Modified Sternal Retractor for Exposure of the Internal Mammary Artery

This report describes the use of a modified chest wall rake retractor used to provide better exposure of the internal mammary artery (IMA). The instrument is easy to use and has been associated with minimal complications. It facilitates the harvesting of the IMA for use in coronary artery bypass grafting and provides better visualization of the retrosternal area for control of hemostasis.     

Amikacin-resistant gram-negative bacilli: correlation of occurrence with amikacin use

The incidence of amikacin resistance among gram-negative bacilli isolated at the New York V.A. Medical Center increased from 2.0% to greater than 7% during an 18-month period from January 1980 to July 1981. This increase coincided with a threefold increase in amikacin use at this institution. The amikacin-resistant (AKR) isolates most frequently recovered in 1981 were species of Klebsiella, Serratia, and Pseudomonas. These organisms were recovered from multiple sites, including urine, sputum, wounds, blood, peritoneal fluid, and pleural fluid. The amikacin-modifying enzyme 6'-N-acetyltransferase was detected in 27 (67.5%) of 40 randomly selected AKR isolates. These data indicate that resistance to amikacin in this hospital is enzymatically mediated in most strains of AKR Klebsiella and Serratia and in about one-third of AKR strains of P. aeruginosa. This finding supports the conclusion that amikacin resistance is enhanced by the pressure of increased amikacin use.     

Percutaneous epidural catheterization for intractable pain in terminal cancer patients

We examined the effects of long-term percutaneous epidural catheterization for pain relief in nine terminally ill gynecologic cancer patients. All patients were free of side-effects such as respiratory depression, nausea, vomiting, urinary retention, or pruritis. Analgesia was excellent in six patients. Puncture-site skin inflammation occurred in four patients. Catheter dislodgement occurred in three patients. Although percutaneous epidural catheters were well tolerated in a few patients for an extended period of time, the frequency of catheter problems demonstrate that other methods such as catheter tunneling or implantable systems should be considered for long-term epidural administration of narcotics. This method appears to be most effective in patients suffering from pain due to nerve root involvement.     

Lamellar keratoplasty with the Barraquer microkeratome. Preliminary clinical study apropos of 7 cases

The authors report the results of a preliminary clinical study about lamellar keratoplasty performed with the Barraquer microkeratome. Seven eyes were operated on by this technique, with good functional and anatomical results. Nevertheless, some problems remain. An accurate diameter of the resected button, concerning both the donor and recipient corneas cannot be exactly predicted. There may also exist some irregularities at the edges of the resection. For these reasons, a good incorporation of the donor cornea into the recipient bed may be difficult. These are the main problems with this technique, which facilitates an improved visual prognosis of lamellar keratoplasty.     

Sequential internal mammary-coronary artery bypass

Since April, 1977, a total of eight patients have undergone sequential bypass grafting of the internal mammary artery (IMA) to the coronary arteries at our institution. The indication for this newly described procedure was either insufficient supply of adequate veins (four patients) or the presence of a diseased aortic wall (two patients). Operative procedures included left IMA bypass to the left anterior descending (LAD) artery and its major diagonal branch in six patients; to the obtuse marginal branch and distal circumflex artery in one patient; and to two consecutive sites on the LAD in one patient. All patients became angina-free after operation for a follow-up period lasting up to 6 years. Recatheterization studies were performed in four patients, in all of whom the IMA sequential grafts were found patent. We believe that IMA sequential grafting is an important option available to the cardiac surgeon in managing some patients with coronary artery disease.     

Renal disease after mitomycin C therapy

Fourteen patients with adenocarcinoma of the gastrointestinal tract and pancreas treated with mitomycin C(MMC) and 5-fluorouracil (5-FU) had renal impairment 6-11 months from the beginning of MMC therapy. Two clinical entities were recognized: an acute fulminating renal failure that was rapidly fatal and a chronic slowly progressive renal impairment. The first entity showed a microangiopathic hemolytic profile with anemia, thrombocytopenia, and erythrocyte fragmentation. Light microscopy and electron microscopy examination of the kidney revealed a primary vascular disease with musculomucoid intimal hyperplasia of arteries and rare fibrin thrombi in arterioles. Interstitial fibrosis, tubular atrophy, and widespread glomerular necrosis were also seen. The disease was ultimately fatal within three to four weeks. The second entity showed a chronic course of renal failure with similar pathologic findings but less pronounced, and a microangiopathic hemolysis was absent. The course in the second group was ultimately fatal between three to eight months.     

Electron microscopic studies of herpes simplex virus type 1 infection of macrophages,T- and B-lymphocytes of mice

Summary The course of infection with herpes simplex virus type 1 (HSV-1) in peritoneal macrophages, phytohemagglutinin (PHA-)stimulated (T-)lymphocytes and lipopolysaccharide (LPS-)stimulated (B-)lymphocytes of NMRI-mice was studied by means of electron microscopy. Non-stimulated as well as thioglycolate-stimulated macrophages were investigated; lymphocytes were derived both from HSV-1-sensitized and non-sensitized animals. The morphological characteristics of the abortive infection in macrophages and T-lymphocytes and of the productive infection in B-lymphocytes are described. No differences were observed between stimulated and non-stimulated cells or cells of sensitized and non-sensitized animals.With 7 Figures     

Management of hepatic injury.

Liver injuries may be due to either blunt or penetrating trauma to the thorax or abdomen. Specific treatment depends on the site and extent of hepatic injury. Following resuscitation with intravenous fluids and blood as needed, surgical therapy is directed to provide hemostasis, remove necrotic liver tissue and promote adequate external drainage in the postoperative period. While local measures are usually sufficient, complex hepatic wounds may require extensive resection and vascular ligature or repair.