Gene expression of bacteriophage SPPI. I. Phage directed protein synthesis

A total of 23 phage specific proteins (including four head and six tail proteins) could be identified after SDS polyacrylamide gel electrophoresis of extracts from phage SPP1 infected Bacillus subtilis cells. The total molecular weight of the proteins amounts to approximately 1.9 X 10(6) daltons, equivalent to the majority of the coding capacity of SPP1 DNA. It can thus be assumed that almost all SPP1 coded proteins have been identified. Protein assignments to phage cistrons were made by analysis of extracts from nonpermissive cells infected with sus-mutants. The SPP1 specified proteins can be subdivided into three groups on the basis of the time of their synthesis during the latent period. Host protein synthesis is not significantly affected by SPP1 infection. Normal expression of host genes appears to be essential for SPP1 growth.     

Aerobically incubated thioglycolate broth disk method for antibiotic susceptibility testing of anaerobes

The anaerobic broth disk (AnBD) method of Wilkins and Thiel and a new modification, designated the thioglycolate broth disk method, were compared with an agar dilution technique. The thioglycolate broth disk method was incubated aerobically (AeTBD) or anaerobically (AnTBD). One hundred anaerobic bacteria representing 15 species were tested with clindamycin, chloramphenicol, erythromycin, penicillin, and tetracycline. Agreement of results by the two methods with minimal inhibitory concentration determinations were: AnBD, 95.2%; AnTBD, 91.5%; AeTBD, 94.5%. With clindamycin, chloramphenicol, and penicillin, the agreement of the AeTBD and agar dilution results was 100%, 100%, and 95%, respectively. Using the AeTBD method, only 1.1% of all tests gave false susceptible readings, whereas 4.4% gave false resistant readings. All susceptibility testing errors occurred with tetracycline, erythromycin, and, to a lesser extent, penicillin. For each method, the changes in designation of bacteria as being susceptible or resistant to an antibiotic between trials primarily involved strains with minimal inhibitory concentrations which were +/- one dilution of the respective breakpoint value. The same situation was true for most bacteria that yielded false resistant readings within each trial. False resistant readings with tetracycline were determined to be unrelated to excess cation content of test media. These results reaffirm the reliability of the AnBD method and indicate that the AeTBD modification is equally reliable. The greater convenience and lower cost of the AeTBD method should make possible more widespread performance of susceptibility testing for anaerobic bacteria in hospital laboratories.     

Prolonged survival following cerebral metastasis from pulmonary cancer

A case is reported of prolonged survival after pneumonectomy for anaplastic carcinoma of the left lung and excision of metastatic anaplastic carcinoma of the brain. The patient has survived for 8 years, 6 months after the lung surgery and 7 years after the brain surgery.     

Analysis of left ventricular wall movement during isovolumic relaxation and its relation to coronary artery disease

Left ventricular angiograms of 60 patients with ischaemic heart disease and 10 normal subjects were digitized frame by frame in order to study abnormalities of wall movement during the period of isovolumic relaxation. Plots were made of regional wall movement around the cavity throughout the cardiac cycle. In normal subjects 1-5 to 3-0 mm of symmetrical outward wall movement occurred during isovolumic relaxation, associated with an apparent increase of left ventricular volume of 10 +/- 4 per cent. The corresponding peak velocities of wall movement were 4-3 to 5-7 cm/s, significantly less than those recorded in the same region of the cavity after mitral valve opening. In patients with ischaemic heart disease, the following abnormalities were encountered: (1) Abnormal inward movement, which, in single coronary artery disease, occurred in the area supplied by the affected vessel. (2) Abnormal outward movement of more than 6 mm in non-affected areas which appeared to be a compensatory phenomenon. (3) An abnormal cavity shape change towards a more circular configuration before mitral valve opening. (4) Reduced peak rates of wall movement in affected areas during systole and filling. It is concluded that such inward wall movement during isovolumic relaxation is abnormal and a sign of local ischaemia whose presence has significant effects on overall left ventricular function in both systole and diastole.     

Effects of viloxazine, an antidepressant agent, on biogenic amine uptake mechanisms and related activities

The effects of viloxazine, a clinically effective antidepressant, on noradrenaline (NA) and 5-hydroxytryptamine (5-HT) uptake and various related pharmacological activities were determined and compared to those of the tricyclic antidepressants desimipramine, imipramine, and amitriptyline. Viloxazine inhibitied [3H]NA uptake in the mouse and rat heart, being maximally about one half as potent as imipramine with a similar onset, but shorter duration of action than imipramine. The drug did not inhibit [3H]NA uptake in rat medulla or hypothalamus in contrast to desimipramine and imipramine, but it did alter [3H]NA metabolites in a similar manner. Viloxazine, like desimipramine, was a weak blocker of mouse brain 5-HT uptake, but differed from desimipramine as it poteniated 5-HT-mediated functions in the mouse and rat, as did imipramine and amitriptyline, the latter drugs being relatively potent blockers of 5-HT uptake. Viloxazine potentiated the L-DOPA behavioural syndrome in the mouse, antagonized reserpine-induced ptosis and hypothermia in the mouse, and inhibited gastric acid secretion in the rat, but was less potent than the tricyclic antidepressants. No appreciable in vivo inhibition of monoamine oxidase (EC 1.4.3.4.) activity in the mouse was exhibited. Like imipramine, the drug potentiated the ocular effects of L-adrenaline in the rabbit. It was similar to imipramine in potency in potentiating the apomorphine-induced gnawing in the mouse. The drug antagonized oxotremorine-induced hypothermia in the mouse but differed from the tricyclic antidepressants in not exhibiting the anticholinergic effects of blocking the tremors, salivation and lacrimation. Thus, viloxazine exhibits activities related to the biogenic amines both similar to and different from the tricyclics desimipramine, imipramine, and amitriptyline. These actions appear to be of relevance with respect to the antidepressant action of this drug.     

Reversible signal abnormalities in the hippocampus and neocortex after prolonged seizures

PURPOSE: To investigate the phenomenon of reversible increased signal intensity of medial temporal lobe structures and cerebral neocortex seen on MR images of six patients with recent prolonged seizure activity. METHODS: After excluding patients with known causes of reversible signal abnormalities (such as hypertensive encephalopathy), we retrospectively reviewed the clinical findings and MR studies of six patients whose MR studies showed reversible signal abnormalities. MR pulse sequences included T2-weighted spin-echo coronal views or conventional short-tau inversion-recovery coronal images of the temporal lobes. RESULTS: All six MR studies showed increased signal intensity within the medial temporal lobe, including the hippocampus in five studies. All follow-up MR examinations showed partial or complete resolution of the hyperintensity within the medial temporal lobe and the neocortex. In one patient, results of a brain biopsy revealed severe cerebral cortical gliosis. Temporal lobectomy performed 4 years later showed moderate cortical gliosis and nonspecific hippocampal cell loss and gliosis. CONCLUSION: Significant hyperintensity within the temporal lobe is demonstrable on MR images after prolonged seizure activity, suggestive of seizure-induced edema or gliosis. Damage to medial temporal lobe structures by prolonged seizure activity indicates a possible mechanism of epileptogenic disorders.     

Mutator genes of the yeast Saccharomyces cerevisiae. Interaction of mutations him and his with mutations blocking three principal pathways of repair of induced DNA damage

During recent years, genes controlling mutation in higher eukaryotes have been found to be involved actively in carcinoma regeneration in cells. In this respect, studying the genetic control of mutagenesis becomes a key direction of research into mechanisms responsible for cancer generation. The results of studying interaction of mutations in the HIM and HSM genes, controlling spontaneous and induced mutagenesis in yeasts, and mutations impairing three known pathways of DNA damage repair in this microorganism, are described in this work. It was shown that mutation rev3 completely blocks UV-induced mutagenesis in all mutants studied. On the other hand, mutation rad2 synergistically interacts with mutations him1, hsm1, hsm3, hsm6, and hsm2, thus enhancing the frequency of UV-induced mutagenesis in double mutants multiple times. Mutations him2 and him3 manifested epistatic interaction with mutation rad2. With mutation rad54, the interaction was epistatic for mutations him1 and hsm2 and was additive for mutations hsm1, him2, and him3. On the basis of the data obtained, we developed a scheme for the appearance of mismatch bases in the process of repair of UV-induced DNA damage.     

Emergency fluid management for hypovolemia

Emergency fluid resuscitation of hypovolemic patients begins with an accurate assessment of the degree of volume depletion as well as identification of the cause and associated abnormalities. On the basis of this information, the proper resuscitative fluid can be chosen and administered by the appropriate route, as guided by the urgency of the situation. Patients with severe volume depletion and those in shock require intravenous fluids. In other situations, oral rehydration is often appropriate. Specific fluids then can be tailored to the individual patient's needs and adjusted as warranted by ongoing monitoring.