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Biomedical subjects

J Johnson

Publications and source records attributed to J Johnson.

At least 721 records · Page 40Linked to original sources
PubMed1977

Purification of methylmalonyl-CoA mutase from Propionibacterium shermanii using affinity chromatography.

A novel procedure for the purification of methylmalonyl-CA mutase from Propionibacterium shermanii has been described which employs affinity chromatography on a column of immobilized vitamin B-12 linked covalently to Sepharose. The method has the advantage of being simple and rapid, thus enabling the purification of the enzyme to near homogeneity with good yields.

Chromatography, Affinity↗
PubMed1977

Selective experimental reinnervation of paralyzed facial muscles.

Amelioration of facial nerve dysfunction has been variably successful and often has resulted in only gross motion. An experimental model has been developed whereby the nerve-muscle pedicle technique used to reinnervate the larynx has been modified to achieve selective reinnervation of paralyzed facial muscles. A series of rabbits underwent facial denervation, following which a nerve-muscle pedicle was transposed to the denervated zygomaticus muscle to achieve selective reinnervation. Subsequent follow-up showed good clinical evidence of reinnervation one to four weeks postoperatively. This was confirmed by electromyographic and histologic findings. It is suggested that the nerve-muscle technique that has been used to correct laryngeal paralysis also may be applied to the selective reinnervation of paralyzed facial muscles.

Animals↗
PubMed1977

A new approach in specific, active immunotherapy.

A vaccinia virus-lysed autochthonous tumor cell vaccine (vaccinia oncolysate) is introduced as a new specific, active immunotherapeutic agent against human cancer. Mouse experiments showed the vaccine to be a safe and potent immune mechanism stimulator. Human experimentation was undertaken in the knowledge of relative safety of the components of the vaccine, i.e. vaccinia vaccine and lysed, autochthonous tumor cells. Vaccine-treated patients had advanced metastatic cancer but reacted to one or more common recall antigen skin tests. None of the 13 patients had untoward responses; 7/13 patients had classic delayed hypersensitivity reactions at the vaccine injection sites; and 2/7 patients with injection site reactions had significant reduction in tumor burden. These results indicate that this vaccine is a specific, active immune mechanism stimulator, and may prove to be a useful therapeutic agent in the treatment of human cancer.

Animals↗
PubMed1977

Laser surgery of a digital angiosarcoma: report of a case and six-year follow-up study.

A single digital angiosarcoma was excised by a carbon dioxide laser with small portions of this tumor excised by the scalpel and the high-frequency electrosurgical knife. The patient has been followed for 6 years without any local recurrence or additional lesions. There is a brief summary of investigative studies with lasers in benign and malignant vascular tumors.

Carbon Dioxide↗
PubMed1977

Further evaluation of the test for detection of antibody-coated bacteria in urine sediment.

To assess the reproducibility of the test for detection of antibody-coated bacteria in urine sediment as it might be used in a diagnostic laboratory for classification of urinary tract infections, multiple urine specimens from 83 patients were tested. The results were reproducible and consistent, or if inconsistent potentially explainable, in all but four patients. The explanation for inconsistencies include the immune response to the infecting bacteria, nonspecificity of the antibody coating the bacteria, antibody in prostatic secretions, and antibody-coated bacteria contaminating the urine specimens.

Antibodies, Bacterial↗
PubMed1977

Anticoccidial activity of salinomycin in floor-pen experiments with broilers.

The anticoccidial agent salinomycin (AHR-3096) was compared at various treatment levels (60 to 100 p.p.m.) in two experiments against unmedicated and either 100 or 121 p.p.m. monensin-medicated groups to evaluate its performance under floor-pen conditions. Various methods for the initial rearing of birds and coccidial exposure were employed to test the efficacy of salinomycin against severe, moderate, and mild coccidiosis. Salinomycin at all treatment levels showed definite anticoccidial activity resulting in improved weights, feed conversion ratios, lesion scores, and mortality compared with unmedicated controls. In pens with severe coccidiosis, this compound demonstrated a significant improvement in all parameters when compared with the corresponding unmedicated controls. Salinomycin-treated pens exposed to light coccidiosis usually had a numerical increase in the parameters over the unmedicated control groups. Statistical analysis of overall main effects on mortality, weight gain, and feed conversion ratio showed no significant differences between the activity of any level of salinomycin and monensin.

Animal Feed↗
PubMed1977

A new method for measurement of cyclic AMP phosphodiesterase activity.

The extreme sensitivity of chicken muscle fructose 1,6-bisphosphatase to inhibition by 5'-AMP has been utilized to develop a new method for the assay of cAMP phosphodiesterase activity. In this method, the substrate (cAMP) is first incubated with phosphodiesterase and the amount of 5'-AMP formed is then determined by measuring the degree of inhibition of fructose 1'6-bisphosphatase activity. The present method conveniently employs the spectrophotometric technique and is sensitive enough to detect the conversion of 50 pmol of cAMP to 5'-AMP in 1 ml of reaction mixture. This method is considered particularly valuable for those laboratories that are not equipped with facilities for measuring radioactivity.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1977

Mycotoxins produced by Aspergillus fumigatus isolated from silage.

Results are presented which show that Aspergillus fumigatus was one of the predominant fungi contaminating moldy silage. Growth of A. fumigatus on silage appeared to depend on a preliminary aerobic fermentation by other natural microflora in silage. The clavine alkaloid, fumigaclavine A, and a new clavine alkaloid designated fumigaclavine C were produced by A. fumigatus. The LD50 of fumigaclavine C was approximately 150 mg/kg oral dose in day-old cockerels.

Animal Feed↗
PubMed1977

Training disadvantaged preschoolers on various fantasy activities: effects on cognitive functioning and impulse control.

Preschool children were trained in 1 of 3 different types of fantasy activities over a school year. The effects of this training were evaluated over a variety of tasks measuring cognitive development and impulse control. The same basic experiment was replicated over 3 different years. Results indicated that physical enactment of fantasy experiences (viz., acting fairy tales or enacting previous experiences) had a sizable effect on many of these variables; while simply listening and discussing was often no more effective than the control condition that merely cut, pasted, etc. Evidence suggested that fantasy play remoter from reality was more facilitative for development than more realistically oriented fantasy play.

Child, Preschool↗
PubMed1976

Hemoglobin Beth Israel. A mutant causing clinically apparent cyanosis.

We found that an abnormal hemoglobin with a very low oxygen affinity was responsible for overt cyanosis in an otherwise healthy adolescent. Hemoglobin Beth Israel, in which serine replaces the asparagine residue normally present at position 102 (G4) of the beta-polypeptide chain, was associated with normal blood counts and no apparent exercise intolerance in the heterozygous carrier. Cyanosis resulted from a drastically right-shifted oxygen dissociation curve, whose position and shape could account for the absence of "physiologic" anemia. The whole-blood oxygen tension at 50 per cent oxygen saturation was 88 mm Hg (normally 26 +/- 1 mm Hg), and the arterial blood was only 63 per cent saturated with oxygen despite a normal oxygen tension of 97 mm Hg. The hemolysate showed a low oxygen affinity but normal Bohr effect. Unexplained cyanosis, particularly in association with normal arterial oxygen tension should prompt a search for an abnormal hemoglobin, which may obviate the need for invasive diagnostic procedures.

Adolescent↗
PubMed1976

Cytotoxicity reactions during immunotherapy of melanoma with neuraminidase altered autologous tumor cells.

Lymphocyte cytotoxicity, serum cytotoxicity, and the ability of the serum to inhibit lymphocyte cytotoxicity (blocking effect) were studied in a melanoma patient treated with six monthly injections of her own (autologous) tumor cells incubated with neuraminidase to increase their antigenicity. The same tumor cells grown in tissue culture were used as target cells for the cytotoxicity test. Large fluctuations of blocking effect in the serum were found, which correlated with the clinical course of tumor removal, recurrence, and regression. After the fifth injection of autologous tumor cells, the blocking effect disappeared from the serum (unblocking). In general, changes in serum cytotoxicity corresponded with changes in the amount of blocking effect produced by the serum. The results suggest that active immunotherapy may play a role in the prevention of metastases and, that when used within the autologous system, the cytotoxicity test is valuable in studying response to this type of therapy.

Antigens, Neoplasm↗
PubMed1976

Operative endoscopy in the management of biliary tract neoplasms.

Operative endoscopy of the biliary system has been employed with ever increasing frequency at the UCLA Hospital during the last three years. In addition to its established value with respect to disclosing unsuspected stones in the bile ducts, choledochoscopy has been of great value in terms of more accurate diagnosis and staging of periampullary and bile duct neoplasms. It has been observed that many biliary tract carcinomas are multicentric in origin and that cholangiography is not adequate to identify small intrahepatic ductal lesions. More than one cell type of bile duct carcinoma may be present in the same patient. Choledochoscopy should be used in addition to the conventional criteria for resectability in all patients with ductal or periampullary carcinoma. Use of this technic will spare some patients needless radical procedures and should improve long-term cure rates by identifying those patients with truly localized disease for curative resections.

Adenocarcinoma↗