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Biomedical subjects

M Johns

Publications and source records attributed to M Johns.

At least 55 records · Page 3Linked to original sources

A portable light source for bright light treatment.

A novel, portable, inexpensive bright light source is described. This unit, which has been demonstrated to exhibit physiological effects similar to those of the more conventional light boxes, offers a less restrictive home treatment for patients with seasonal affective disorder and sleep disorders.

Adult↗

Synthesis of oligophosphoseryl sequences occurring in casein. Identification of beta-elimination during phosphorylation.

The protected oligophosphoseryl peptides from bovine caseins, Z-Xxx-(Ser[PO(OPh)2])3-Glu(OBzl)-OBzl for Xxx = Ile, Val, Gly, Leu and Ph = phenyl, were synthesized in high yields by stepwise lengthening using Boc-Ser[PO(OPh)2]-OH as acylating carboxyl component and N-ethyl-N'-(3-dimethylaminopropyl)-carbodiimide hydrochloride as coupling reagent. The hydrogenolytic deprotection (PtO2) was carried out with the valine derivative and with the tetrapeptide Ser[PO(OPh)2]3-Glu(OBz)-OBzl. Phosphorylation of oligoseryl peptides failed to give the expected products. Large scale phosphorylation of protected serine was carried out in the presence of triethylamine using absolute ether as a solvent. 2,2,2-Trichloroethyl group (Tc) was shown to be a useful phosphorus protecting moiety in phosphopeptide synthesis: Boc-Ser[PO(OTc)2]-OBzl, Z-Ser[PO(OTc)2]-OBzl and Boc-Glu(OBzl)-Ser[PO(OTc)2]-OBzl were synthesized in high yields using bis-(2,2,2-trichloroethyl) phosphochloridate.

Amino Acid Sequence↗

The effect of intravenous nutrition on muscle mass and exercise capacity in perioperative patients.

This study was undertaken to compare the efficacy of four different types of perioperative intravenous nutritional support. Fifty-five patients undergoing routine major surgery were studied. They were prospectively assigned to one of four study groups. Group 1 received formal total parenteral nutrition (90 g amino acids, 3,000 calories as glucose, per day); Group 2, 100 g glucose per day; Group 3, 90 g amino acids per day; and Group 4, peripheral parenteral nutrition (90 g amino acids plus 1,600 calories, 60 percent as fat per day). Group 1 was maintained on therapy for 3 weeks and the other groups for 8 days. Nitrogen balance, maintenance of body cell mass, serum albumin levels, and maintenance of exercise capacity were measured. Patients receiving peripheral parenteral nutrition maintained their nutritional parameters, as did those receiving total parenteral nutrition. These infusions were both markedly superior to those receiving glucose alone or those receiving amino acids alone. Nitrogen balance was not correlated with maintenance of function, but maintenance of body cell mass was correlated with maintenance of exercise capacity (r = 0.66, p less than or equal to 0.01). We conclude that perioperative peripheral parenteral nutrition, in contradistinction to hypocaloric infusions of glucose or amino acids, is capable of maintaining postoperative muscle mass and function close to preoperative levels after major surgery, and in situations of relatively mild surgical stress, approaches the efficacy of total parenteral nutrition in this regard. A significant correlation exists between changes in body cell mass determined from isotope dilution and changes in the exercise capacity of large muscle masses.

Adult↗

Goals and mechanisms for training otolaryngologists in the area of geriatric medicine.

Population dynamics indicate that the need for services by otolaryngologist-head and neck surgeons will increase. These requirements will also be more complex because of the prevalence of other diseases in the elderly and their varied social and psychological demands. To meet that need, additional research in head and neck disorders and physiology will be necessary. Current and newly developed information relating to geriatrics in otolaryngology must be incorporated into present training and continuing education programs to provide members of our specialty with enough background to adequately diagnose and treat head and neck disorders in the elderly. Otolaryngologist - head and neck surgeons and their elderly patients will benefit from the creation of centers and fellowships that study pathologic processes and normal physiologic change, and that train a new generation of physician-scientists committed to the care of elderly head and neck patients.

Aged↗

Endotoxin-associated protein: a potent stimulus for human granulocytopoietic activity which may be accessory cell independent.

Proteins coextracted with endotoxin, termed endotoxin-associated protein (EAP), have been shown to exert interleukin 1-like activities. The present studies demonstrate that EAP also exerts potent granulopoietic colony-stimulating activity (CSA) on human peripheral blood and bone marrow progenitor cells, comparable to that seen with various types of conditioned media. The CSA observed with EAP appeared to be heat (100 degrees C, 30 min) and trypsin resistant and partially pronase resistant. Similar resistance was observed with the porin proteins of the outer membrane of gram-negative bacteria, and similar CSA activity was observed with a purified porin preparation of Neisseria gonorrhoeae. The CSA of EAP could be demonstrated in human peripheral blood and bone marrow leukocytes rigorously depleted of monocytes, T lymphocytes, and B lymphocytes by treatment with specific monoclonal antibodies and complement.

Antigen-Presenting Cells↗

1987 AMRA reverification of competencies.

Reverification of the AMRA competency statements on a regular basis ensures the relevancy of the national accreditation and registration examinations to current practice. This article has described the historical perspective in which the 1987 competency reverification project was performed. The methodology and findings of the study have also been described. Recommendations have ben made for using the competencies as a guide for curriculum definition. The need for further refinement of the competency identification methodology as well as AMRA's current research project in this area have also been discussed.

Certification↗

Response of cranial nerve abnormalities in nasopharyngeal carcinoma to radiation therapy.

Eighteen of 36 patients (50%) with the diagnosis of nasopharyngeal carcinoma had cranial nerve deficits before definitive radiotherapy. Within this group of 18 patients, there were 34 cranial nerve abnormalities and four Horner's syndromes. Overall, 62% of cranial nerve deficits recovered completely (CR) and 32% recovered partially (PR), for a total response rate of 94% to definitive radiotherapy. The magnitude of response (complete versus partial) depended upon the individual cranial nerve and the pretreatment duration of the abnormality. All of the responses except one occurred within 1 month after the completion of therapy. Complete responses were not obtained when deficits had existed longer than 2 months. However, PRs were obtainable. Seven of seven cases of posttreatment new or recurrent cranial nerve deficits were caused by recurrent tumor. The actuarial 5-year disease-free survival for this group of 18 patients was 31%. The results indicate that patients with cranial nerve deficits will respond to definitive radiotherapy and long-term disease-free survival can be achieved in some patients.

Adolescent↗

Clinical evaluation of patients with metastatic squamous carcinoma of the neck with occult primary tumor.

Between 1976 and 1982, we systematically evaluated 33 patients with a diagnosis of metastatic squamous carcinoma of the neck (excluding the supraclavicular fossa) from an occult primary tumor. In 11 patients the primary lesion was identified by physical and indirect mirror examinations, in four by examinations done under anesthesia and panendoscopies, and in an additional three by random biopsies. Primary lesions were in the nasopharynx (five patients), hypopharynx (five), tonsillar fossa (three), epiglottis (two), lateral oropharyngeal wall (one), the base of the tongue (one), and the anterior tonsillar pillar (one). In 15 patients (45%), the primary lesion was not identified after complete evaluation; these patients remained free of primary lesions in the head and neck area during a follow-up of two to six years. Our results indicate that patients with metastatic carcinoma of the neck should have a complete evaluation before treatment is started; in the majority of these patients, the primary site can be identified, with a resultant change in the treatment plan. A review of the literature shows that metastatic squamous carcinoma of the neck with an unknown primary tumor is a treatable disease with a cure rate as high as 50%.

Adult↗

Class structure and spatial polarization: an assessment of recent urban trends in Latin America.

"In this paper, we review those major trends characteristic of peripheral urbanization as they are reflected in the recent Latin American experience. Such trends include: urban primacy and the relative absence of secondary city systems, the character and dynamics of the informal sector, housing deficiencies and state housing policy, and the recent rise of popular organizations oriented toward self-sufficiency or militant demand-making. These trends are important because they represent the form in which continuity and change of peripheral class structures are reflected in space, both at the national and local levels....[The authors conclude that] the political economy of Latin American cities is one where the resolution to the plight of underdevelopment promised by accelerated capitalist industrialization has not materialized. Instead, the process has produced a more complex and more contradictory social fabric."

Americas↗

Immunization with rough mutants of Salmonella minnesota. IV. Protection by antisera to O and rough antigens against endotoxin.

The protection by antisera to O antigens and antigens (lipid A, the Re 595 mutant of Salmonella minnesota, and the J5 mutant of Escherichia coli) of the core portion of endotoxin against lethal challenge with lipopolysaccharide (LPS) was compared. Rabbits immunized with the Re mutant developed antibody that protected mice against challenge with S. minnesota or Salmonella typhosa LPS. Antisera to heterologous O antigen and lipid A were not protective, whereas homologous antisera and antiserum to the Re or J5 mutant protected against lethal challenge. On a volumetric basis, O-specific antiserum was consistently somewhat more protective than antiserum to the Re mutant, which was slightly more protective than antiserum to the J5 mutant. When comparisons were made using passive transfer to similar quantities of hemagglutinating or precipitating antibody, antiserum to the Re mutant was considerably more protective than O-specific antiserum. This greater protection is hypothesized to result from more effective masking of the toxic lipid A moiety by antibody to the rough mutants than by O-specific antibody.

Animals↗

DNA/anti-DNA complexes: correlation of size and complement fixation.

The hydrodynamic sizes of antibody/3H-dsDNA immune complexes are correlated with their ability to fix complement in a red blood cell-complement linked binding assay. The results with PM2 dsDNA and a sonicated preparation (with a molecular weight of approximately 5.10(5) suggest that packing considerations are also important in the complement binding reaction. The relevance of these findings with respect to the role of antibody/dsDNA immune complexes in the pathogenesis of glomerulonephritis in systemic lupus erythematosus is discussed.

Antigen-Antibody Complex↗

Effect of stenosed and occluded coronary arteries on immediate and late myocardial uptake of thallium-201.

Exercise and redistribution myocardial scintigraphy using thallium-201 was compared with the left ventricular angiogram and with the presence of stenosis or occlusion of coronary arteries on angiography. Irreversible scintigraphic defects representing areas of myocardial infarction were found in all patients with occlusion of the left anterior descending artery but nearly one-third of patients with stenosis of that artery also showed evidence of infarction. For the right coronary or circumflex arteries the incidence of infarction was 82% with vessel occlusion and 57% with vessel stenosis. Of abnormally contracting segments on the left ventricular angiogram, 95% showed irreversible scintigraphic defects but 33% of normally contracting segments supplied by a diseased artery also showed this. Myocardial infarction is not uncommon in patients with angina even in the absence of coronary occlusion. The incidence is underestimated by the left ventricular angiogram. These findings are of importance in the assessment of patients with coronary disease and their evaluation before coronary artery surgery.

Angiocardiography↗

Potential use of shared antigens for immunization against gram-negative bacillary infections.

The demonstration of common antigens shared by all Enterobacteriaceae has led to evaluation of the effects of immunization of animals and man with these antigens in protecting against bacterial infections and challenge with LPS. Both active and passive immunization with the Re mutant of S. minnesota and the J5 mutant of E. coli afforded significant protection to mice and rabbits against lethal challenge with viable bacteria and heterologous LPS. KDO appears to be the antigenic determinant responsible for induction of protective antibody after immunization with the Re mutant but the antigenic determinant of the J5 mutant has yet to be identified. Studies in volunteers indicate that human immunization with R mutants can be accomplished without excess adverse reactions and that such immunization may protect against Gram-negative bacillary infections.

Animals↗