Arginine aminopeptidase activity of phytopathogenic spiroplasmas

The arginine aminopeptidase activity of arginine-utilizing phytopathogenic spiroplasmas was investigated with arginine beta-naphthylamide substrate using the fluorometric method. Hydrolysis of this substrate was demonstrated with broth cultures, washed concentrated whole cells, and cell-free extracts of corn stunt spiroplasma (CSS) and Spiroplasma citri. Growing CSS and S. citri in the presence of 47 mM arginine resulted in a reduction in aminopeptidase activity, indicating that synthesis of the enzyme might be subject to control by catabolic repression. Results of these experiments suggest a possible biochemical basis for pathogenicity of phytopathogenic spiroplasmas in vivo.

Expansion of the left atrial appendage is a distinctive cross-sectional echocardiographic feature of congenital defect of the pericardium

A case report of a congenital defect of the pericardium in which the cross-sectional appearance of a prominent left atrial appendage is similar to the previously reported angiographic diagnostic appearance.

Relationship between a pulmonary function test (FEV1) and the ADAPT quality-of-life scale

In a previous study the Additive Daily Activities Profile Test (ADAPT) correlated .83 with maximum oxygen consumption among pulmonary rehabilitation patients. The present study expanded the pulmonary population base and compared the ADAPT scores of 41 patients at two independent centers with a more readily available parameter, the forced expiratory volume in the first second of forced exhalation (FEV1). The relationships between the two major ADAPT subscales and FEV1 were significant but lower in magnitude than that found with maximum oxygen consumption. The ADAPT continues to be sensitive to physical impairment and in translating the effect of impairment upon daily physical activity.

L-dopa treatment of Parkinson's disease: a ten-year follow up study

A ten-year follow-up study of parkinsonian patients treated with L-dopa is presented. Originally 130 patients entered the study, and previous reports were presented in 1971 and 1973. This report concerns the 47 remaining patients now available for examination. The effectiveness of L-dopa diminished over the ten-year period, so that the disability states of these patients are now similar to those prevailing just before the study began ten years ago. Despite the decline, the interim improvement and the patients' relatively asymptomatic existence for part of the time confirm the effectiveness of L-dopa therapy in the treatment of Parkinson's disease.

Transfusion-transmitted viruses study: experimental evidence for two non-A, non-B, hepatitis agents

Plasma, serum, and a concentrate of factor VIII, implicated in human cases of non-A, non-B (NANB) hepatitis, were inoculated into four chimpanzees. All four animals demonstrated significant elevations of alanine aminotransferase levels within five weeks. After recovery from these NANB hepatitis episodes, the chimpanzees were cross-challenged with different inocula. A second episode of NANB hepatitis occurred after challenge in three animals. Reproducibility of the results was established by reversing the sequence of inoculation in two of the animals. A known infectious concentrate of factor VIII failed to induce hepatitis in a previously infected chimpanzee although the animal remained susceptible to a third inoculum, an event suggesting that the first inoculum might contain the same NANB hepatitis agent as the concentrate of factor VIII, which was supported by results of a subsequent cross-challenge experiment. Reinfection did not occur in two chimpanzees injected with their initial challenge strain of NANB hepatitis virus, providing evidence that strain-specific immunity had been established. Thus, experimental evidence is provided for the presence of two NANB hepatitis agents, supporting clinical and epidemiologic studies that favor the existence of more than one etiologic agent.

An in vitro comparison of some biochemical and biological properties of California and Morocco isolates of Spiroplasma citri

California (CI) and Morocco (MI) isolates of Spiroplasma citri incubated at 4, 24, or 32 °C yielded typical mycoplasma colonies on agar at each passage. MI but not CI incubated at 37 °C yielded a few colonies at first passage only, but both isolates did not survive 42 °C for 3 days. In liquid and solid media, best growth of both isolates occurred between pH 7.0 and pH 8.5 and the optimum pH for growth in liquid medium was 7.5 (CI) and 8.5 (MI). The sensitivity of CI or MI to 21 antimicrobial substances was identical in most cases. Corn stunt spiroplasma (CSS) and CI had similar antimicrobial substance spectrum, although CSS was much more sensitive to any given substance than CI. CI fermented the following with acid production: cellobiose, dextrose, galactose, trehalose, fructose, mannitol. maltose, and sucrose. MI fermented all these in addition to arabinose, mannose. sorbitol, and raffinnose. Arginine but not urea was hydrolyzed by both isolates. CI or MI failed to reduce potassium tellurite, methylene blue, or tetrazolium chloride.

Angiotensin convertase activities in human alveolar macrophages: effects of cigarette smoking and sarcoidosis

Angiotensin I convertase activity has been found in human alveolar macrophages from normal volunteers and patients with pulmonary sarcoidosis. This activity is higher in the alveolar macrophages from smokers than from nonsmokers, and is even more elevated in sarcoid patients. The activity can be detected with both angiotensin I and bradykinin analogs and appears to require protein synthesis, but the enzyme is not secreted by alveolar macrophages in culture.

Binding of beryllium to nuclear acidic proteins

In vitro beryllium (Be) binding to rat liver nuclei has been reassessed (KAss = 2.0 X 10(6) M: n = 17 nmol Be/mg protein). Be also binds to rat liver nucleoli (KAss approx. 4 X 10(6) M: n = 10 nmol Be/mg protein). Examination of rat liver chromatin fractionated on a hydroxyapatite column shows that Be does not bind to histone or to the non-histone protein eluted by 0.05 M sodium phosphate. Be is strongly bound to the non-histone proteins eluted by 0.2 M sodium phosphate (KAss = 1.1 X 10(6) M: n = 55 nmol Be/mg protein) and also to the same extent to the fraction containing DNA which is subsequently eluted from the column. Evidence is provided that the latter binding is not due to DNA. The fractions containing the Be-binding proteins also contain the proteins which are phosphorylated to the greater extent.

Partial purification and characterization of the soluble DNA polymerase (polymerase-α) from seedlings of Pisum sativum L

Soluble DNA polymerase has been extracted from pea seedlings and partially purified by chromatography on columns of DEAE-cellulose or DEAE-Sephadex. The enzyme elutes from DEAE-cellulose as a single peak, but is fractionated into three peaks, SI, SIa and SII by DEAE-Sephadex chromatography. SIa and SII may be derived from SI by freeze-thaw treatment or by treatment with (NH4)2SO4. The ion and pH requirements and the sensitivity to N-ethyl maleimide of the pea seedling soluble DNA polymerase are similar to those of the DNA polymerase-α from vertebrates.

Chromatin-bound DNA polymerase from higher plants : A DNA polymerase-β-like enzyme

Chromatin-bound DNA polymerase has been extracted from pea (Pisum sativum L.) seedlings, and partially purified by solubilization from chromatin followed by chromatography on columns of either DEAE-cellulose or DEAE-Sephadex. The enzyme elutes from DEAE-cellulose as a single peak, but is fractionated into two peaks, CI and CII, by DEAE-Sephadex chromatography. If the enzyme is stored at-15°C for several days prior to chromatography, a third peak, CIII, derived from CII, is obtained. The polymerase is devoid of nuclease activity, and is relatively insensitive to N-ethyl-maleimide. These features, taken with the ion requirements and with data obtained from other plant species, lead to the suggestion that the chromatin-bound DNA polymerase of higher plants is similar to the DNA polymerase-β from vertebrates.

Responses to moral dilemmas in medical students and psychiatric residents

There has been an increasing interest in the area of medical ethics as indicated not only by the recent proliferation of books and articles but also in the re-emergence of crucial moral issues such as euthanasia, abortion and the like. The difficulty with the existing literature is that these reports are often descriptive, anecdotal and situationally relative to the decision maker. In this study, the authors utilized a cognitive developmental approach to studying responses to moral situations not only because this approach is cross-culturally universal but also because it is not subject to situational variables. In this regard, the results of the assessment of medical students and psychiatric residents are presented as well as a comparison of moral reasoning stages in relation to the C.M.A. Code of Ethics. Recommendations for further research are presented.

Consumer and provider attitudes toward dentist and expanded auxiliary functions

Consumers, dentists, dental students, dental assistants, dental hygienists, dental assistant trainees, and dental hygiene students in Massachusetts were surveyed for their attitudes toward the concept of expanded-duties auxiliaries. The Osgood sematic differential technique was used, in which study participants were asked to respond to line drawings of a dentist or an auxiliary performing each of three different procedures: cutting tooth structure, placing a restoration, and taking radiographs. The results indicate that most of the groups perceived significant differences between cavity preparation by the dentist and by the auxiliary: they were modierately positive toward the former, near neutral toward the latter. Groups were more positive toward cavity restoration, generally perceiving fewer, but still significant, differences between the dentist and auxiliary as operatiors. All groups were most positive toward taking radiographs and perceived no difference between the two operators. Of all groups, the dentists perceived the greatest difference between operators; dental hygienists and dental hygiene students were the most positive and saw the least differences between operators. Consumers were the least positive to all procedures and perveived only modirate differences between the two operators. In other words, the consumers did not seem overly concerned with who provided the dental care; they just did not like the services themselves. In the study, the consumer was more concerned with the procedure than with the different operators, whereas the dentist was more concerned about the operator.

Ammonia intoxication: a hazard during rehabilitation of protein-deprived rats

The ammonia tolerance of weanling rats raised for 3 to 6 weeks on a protein-deficient diet was compared with that of a group of age-matched control animals raised from weaning on an optimal protein diet. The groups were challenged with a nitrogen load of either ammonium chloride or amino acids. The results of the loading studies indicate that severe protein deprivation increases vulnerability to ammonia poisoning. These observations suggest that ammonia-induced coma may pose a significant hazard during the initial intravenous rehabilitation of malnourished subjects, if replenishment is undertaken too vigorously.