The human met oncogene is related to the tyrosine kinase oncogenes

The met oncogene was previously isolated from a chemically transformed human cell line, MNNG-HOS. Recent evidence has demonstrated that two classes of transcripts are expressed from the met proto-oncogene locus. The met oncogene, however, expresses an aberrant RNA which has sequences in common with both transcripts. We now report partial nucleotide sequencing of the human met oncogene and show that met is related to the protein kinase oncogenes and growth factor receptors. The met nucleotide sequence is not identical to that of any published gene, and it is more closely homologous to the tyrosine kinases than to the serine/threonine kinases. Within the tyrosine kinase family, the sequenced met domains are most closely related to the human insulin receptor and the viral abl gene. In situ chromosome hybridization has mapped met to human chromosome 7 band 7q21-q31, a location distinct from that of other kinases. This is also a region associated with nonrandom chromosomal deletions observed in a portion of patients with acute nonlymphocytic leukaemia. The accompanying paper shows that this chromosomal locus is also tightly linked with the human heredity disease cystic fibrosis.

Identification in several human myeloid leukemias or cell lines of a DNA rearrangement next to the c-mos 3'-end

A characteristic DNA rearrangement, the loss of an EcoRI cleavage site next to the 3'-end of the human c-mos gene, has been found to be frequently present in DNA from transformed hematopoietic cells of the myeloid lineage but not in DNA from either normal or transformed cells of different tissue types. Three established cell lines, respectively a pro-monocytic line (CM-S) and two precursor granulocytic lines (My/K1 and My/K5), carry the same genome rearrangement, but not fibroblasts obtained from the marrow of the same patients. This DNA rearrangement is maintained in three different hybridomas derived by fusion of CM-S cells with normal human embryo hepatocytes.

The effect of acute exercise on natural killer-cell activity of trained and sedentary human subjects

The effect of acute exercise on natural killer (NK) activity and on the distribution of phenotypic characteristics of peripheral blood lymphocytes was examined. Trained and sedentary individuals underwent a standard progressive exercise test on a cycle ergometer using an incremental work load of 15 W (90 kpm), increased every minute. Each subject was encouraged to exercise to exhaustion, and total ventilation and mixed expired O2 and CO2 were measured every 30 sec. All subjects reached the "anaerobic" threshold as judged by the deflection of ventilation at a work load near VO2max. NK activity against K562 reached maximum levels immediately after exercise, dropped to a low point 120 min later, then slowly came back to preexercise levels within 20 hr. No significant differences were observed between the trained and the sedentary groups. Furthermore, immediately after exercise the proportion of OKT-3+ and OKT-4+ cells was reduced by 29.8 +/- 3.6 and 33.6 +/- 5.4%, respectively; the percentage Leu-7+ and Leu-11a+ cells was increased by 53.9 +/- 1.7 and 57.3 +/- 2.9%, respectively. The percentage OKT-8+ cells was not significantly altered. When the percentage binding of effector to target cells was examined, it was highest at 0 min post-exercise (19 +/- 6.2%) and lowest at 120 min postexercise (7 +/- 3.9%), but the absolute number of NK cells remained unchanged. The source of serum used in the lytic assay had no effect on the NK activity, as fetal calf serum and autologous sera drawn at different time intervals during exercise gave similar results.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacokinetics of amikacin in the horse following intravenous and intramuscular administration

The pharmacokinetics of amikacin sulfate (AK) were studied in the horse after intravenous (i.v.) and intramuscular (i.m.) administration. Serum (Cs), synovial (Csf) and peritoneal (Cpf) fluid concentrations of the drug were measured. Doses of 4.4, 6.6 and 11.0 mg/kg were given. The concentrations at 15 min following i.v. injection were 30.3 +/- 0.3, 61.2 +/- 6.9 and 122.8 +/- 7.4 micrograms/ml, respectively, for the 4.4, 6.6 and 11.0 mg/kg doses. Mean peak Cs values after the intramuscular injections occurred at 1.0 h post-injection and were 13.3 +/- 1.6, 23.0 +/- 0.6 and 29.8 +/- 3.2 micrograms/ml, respectively. The t 1/2 of amikacin was 1.44, 1.57 and 1.14 h for the 4.4, 6.6 and 11.0 mg/kg doses, respectively. In this study, minimum inhibitory concentrations (MIC) of amikacin sulfate were determined for six pathogens. Based on the MIC and the pharmacokinetic parameters, it would appear that the usual therapeutic dose of amikacin would be between 4.4 and 6.6 mg/kg twice daily and, for the more serious life-threatening infections, dosing three times a day.

Herpes simplex virus sequences involved in the initiation of oncogenic morphological transformation of rat cells are not required for maintenance of the transformed state

We have determined the herpes simplex virus (HSV) type 2 DNA sequences responsible for the initiation of morphological transformation and have investigated the retention and expression of these sequences in morphologically transformed cells and in tumours derived from these cells. All the transformed cells analysed were selected by a focus formation assay and are oncogenic in the inbred host rat. Cloned HindIII and Bg/II fragments from the HSV-2 genome were assayed for the ability to initiate morphological transformation of rat embryo cells. Only the HindIII a (map units 0.52 to 0.72) and the Bg/II n (0.582 to 0.612) clones gave transformed foci. This shows that the Bg/II n region is responsible for initiation of transformation. Southern blot analysis of DNA extracted from these transformed cells and from tumours derived from these transformed cells revealed that neither the Bg/II n fragment nor fragments of 500 bp mapping within it are detected at the level of one copy per cell and therefore need not be retained in the cell to maintain the oncogenic phenotype. In addition there was no evidence of expression of the HSV-specified ribonucleotide reductase activity which is partially encoded within the Bg/II n fragment of HSV-2. We also analysed DNA from rat embryo cells transformed by ts mutants of HSV-2 (HG52) or HSV-1 (HFEM or 17) at non-permissive temperature or by virus at supraoptimal temperature or by sheared virus DNA and DNA from tumours derived from lines of these transformed cells. In addition, we cloned both transformed and tumour cell lines and analysed these similarly. In no case could we detect HSV DNA sequences at the level of one copy per cell.

Molecular cloning of a new transforming gene from a chemically transformed human cell line

Molecular cloning of the transforming gene from a chemically transformed human osteosarcoma-derived cell line enables the gene to be mapped to chromosome 7 (7p11.4-7qter) and by this criterion and by direct hybridization to be shown to be unrelated to known oncogenes.

A single preoperative dose of cefazolin prevents postoperative sepsis in high-risk biliary surgery

To test the ability of cefazolin, given in a single dose preoperatively, to prevent infection in high-risk patients after biliary tract surgery, the authors conducted a double-blind, prospective, randomized, controlled study. Of 92 patients operated on for acute cholecystitis or bile-duct disease, 46 were given 2 g of cefazolin intravenously before operation. Bile was contaminated with bacteria in 36% to 50% of patients with acute cholecystitis, obstructive jaundice, bile-duct disease without jaundice, or over 50 years old compared with only 5% of patients with chronic cholecystitis or under 50 years of age. Postoperative sepsis was eight times more frequent in patients with contaminated bile than in those without. Only 1 patient who received cefazolin had a wound infection, but 9 of the 46 patients in the control group did. The bacteria causing wound sepsis were similar to those in the contaminated bile. The authors conclude that a single dose of cefazolin given intravenously before operation provides effective prophylaxis against infection in high-risk biliary tract surgery.

Are first-generation cephalosporins effective for antibiotic prophylaxis in elective surgery of the colon?

First-generation cephalosporins have recently declined in popularity as antibiotics for prophylaxis in elective surgery of the colon, but their efficacy has not been defined precisely. In a prospective randomized study, 44 patients who underwent elective colonic operations received, preoperatively, cefazolin in a parenteral dose adequate to kill aerobic coliforms. Six had wound infections; Bacteroides fragilis was grown, along with other organisms, from all these wounds. In contrast, only 1 of 57 similar patients had a wound infection after receiving, preoperatively, erythromycin base and metronidazole orally--directed at anaerobic bacteria. Local contamination, predominantly by anaerobic bacteria, is the main cause of wound infection after elective surgery of the colon. Even in what seems to be adequate dosage, first-generation cephalosporins are not antibiotics of first choice for preventing wound infections after these operations.

Detection of herpes simplex virus type-2 DNA restriction fragments in human cervical carcinoma tissue

DNA extracted from eight human cervical carcinomas, one lymph node metastasis and related control tissue was examined for the presence of herpes simplex virus (HSV) DNA sequences. Southern blot transfers of tumour and control DNA were hybridised with radioactively labelled cloned probes representing 70% of the HSV-2 genome. Specific hybridisation to HSV DNA sequences was observed in one of eight carcinoma tissues analysed. Hybridisation of HSV-2 DNA probes to BamHI and XhoI restriction enzyme fragments of tumour cell DNA which co-migrated with authentic HSV-2 viral fragments identified co-linear HSV-2 DNA sequences comprising 3% of the HSV-2 genome, between map coordinates 0.582 and 0.612. The remaining eight tumour and all control tissues analysed, showed no specific hybridisation to any of the probes used at levels of sensitivity which would detect 0.5 copies/cell of HSV-2 DNA restriction fragments of 2 kb or greater.

Induction of a latent herpes simplex virus from a rat tumour initiated by herpes simplex virus-transformed cells

A rat tumour induced by cells transformed with the sheared DNA of herpes simplex virus (HSV) type 1 HFEM alpha (RE2A) was injected with the intertypic virus HSV-2 HG52 ts 1. Separate plaques, isolated from cocultivation of excised tumour tissue with susceptible cells, yielded virus the DNA of which had the restriction enzyme profile either of the injected HSV-2 virus or that of the HSV-1 virus, originally used to transform the cells. No evidence of in vivo recombination was detected. In Hooded Lister rats, HSV may have the ability to remain in a latent or non-replicating state in fibroblasts.

Cefamandole in gastroduodenal surgery: a controlled, prospective, randomized, double-blind study

Acceptance of the value of antibiotic prophylaxis in gastroduodenal surgery is growing, but only one controlled, double-blind study justifying this is available. In this second, controlled, randomized, double-blind study 60 patients underwent urgent and elective gastroduodenal operations. Among 32 patients receiving cefamandole perioperatively for prophylaxis, only 1 subsequently had a wound infection, but wound infections occurred in 8 of the 28 patients who received a placebo (P less than 0.01). Infection rates were higher in contaminated wounds and in urgent operations than in clean-contaminated wounds and elective surgery. The results confirm the value of antibiotic prophylaxis in this setting.

The conduct of cholecystectomy: incision, drainage, bacteriology and postoperative complications

The benefits of some ancillary techniques of cholecystectomy are exaggerated by retrospective study of selected patients. Therefore, the authors performed a prospective, randomized study of 100 consecutive patients who underwent simple elective cholecystectomy for chronic cholecystitis and cholelithiasis. No patient was excluded because of incomplete hemostasis or fear of bile leakage. The frequency of pulmonary complications and wound infections was independent of the type of incision--vertical or subcostal. Peritoneal drainage was found to be unnecessary. Short-term drainage may increase the frequency of postoperative fever, but did not increase pulmonary complications or wound infections. In these patients, intra-abdominal sepsis is rare; wound infections were uncommon and the gallbladder bile was usually sterile and not the cause of postoperative infection.

Preventing anaerobic infection in surgery of the colon

A randomized prospective study of antibiotic prophylaxis was carried out in patients who underwent elective surgery of the colon. The wound infection rate in 70 patients who received cephradine intravenously in the perioperative period (group 1) was 25%, compared with 8% in 60 patients who received metronidazole and erythromycin base orally before operation (group 2). Both Bacteroides fragilis and Escherichia coli were cultured from the majority of wound infections in group 1, but B. fragilis was not found in any group 2 patients. Wound contamination indicated by wound class or by culture of the subcutaneous tissue of the wound before closure was the best predictor of subsequent wound infections. These results suggest a dominant role for intestinal anaerobes in the genesis of wound infections after colonic surgery and show that antibiotics specifically directed against these organisms can substantially reduce the rate of wound infection.

Lack of correlation between exercise capacity and indexes of resting left ventricular performance in heart failure

Symptoms of congestive heart failure occur most commonly during exercise, but cardiac performance is usually quantitated at rest. The relation between exercise capacity and measurements of cardiac performance at rest is little known. Treadmill exercise was performed in 21 patients with heart failure due to cardiomyopathy. Exercise duration averaged 9.1 +/- 0.7 (standard error of the mean) minutes (normal value 12 or more minutes) and did not correlate with resting ejection fraction of 26.4 +/- 2.7 percent (r = -0.06). Left ventricular diastolic dimension of 6.6 +/0 0.2 cm, mean velocity of circumferential fiber shortening and ratio of preejection period to left ventricular ejection time did not correlate with treadmill time (r = -0.03). Repeat studies after treatment of heart failure also failed to show correlations between changes in exercise capacity and changes in left ventricular performance at rest. Thus, measures of left ventricular performance obtained at rest do not accurately reflect exercise tolerance and symptomatic status of patients with congestive heart failure.

Genetic retrieval of viral genome sequences from herpes simplex virus transformed cells

Oncogenic transformation of cultured cells by inactivated herpes simplex virus (HSV) types 1 and 2 has been demonstrated. Expression of HSV information in these transformed cells has been shown by immunofluorescence studies, detection of HSV neutralizing antibody in sera from tumour-bearing animals and by hybridization of HSV-specific RNA. Molecular hybridization studies of DNA from HSV-2 transformed hamster cells have detected up to 40% of the HSV genome present in several copies. Complementation of three HSV-2 temperature-sensitive mutants when superinfecting the RE1 rat embryo cell line (transformed by the HSV-2 temperature-sensitive mutant ts1) suggests that resident viral genes can be expressed. Brown et al. used a similar approach to detect HSV information latent in human ganglia. We report here retrieval of intertypic HSV recombinants from HSV transformed cells after superinfection with ts mutants of the alternative serotype of HSV. Restriction enzyme analysis which clearly differentiates between HSV-1 and HSV-2 DNA has demonstrated the isolation of recombinants spanning the genome and of virus indistinguishable from the original transforming virus.

Plasma angiotensin II levels in hypoxic and hypovolemic stress in unanesthetized rabbits

Plasma levels of angiotensin II were determined by radioimmunoassay in unanesthetized white rabbits exposed to acute hypoxia (FIO2 10% for 10 min), chronic hypoxia (0.5 atm up to 16 days), or hypovolemic stress (bleeding 20 ml/kg). Angiotensin II levels significantly decreased after 10 min of acute hypoxia in normal rabbits and significantly increased when the same procedure was applied to animals previously exposed to hypoxia by 6-8 days of permanence in the hypobaric chamber or sodium deprivation. Chronic hypoxia resulted in a temporary increase of angiotensin II already evident on the 3rd day, but maximal at the 9th day with return to normal values within 16 days. Hypovolemic stress resulted in the expected rise of angiotensin II levels 10 min postbleeding both in normal and acclimatized rabbits. The response of the renin-angiotensin-aldosterone system to hypoxic and hypovolemic stress is different. The direction and magnitude of the response to hypoxia depends on the underlying state of activation of the system and the cardiovascular condition of the animal at the time of hypoxic stress.