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Biomedical subjects

J Wright

Publications and source records attributed to J Wright.

At least 505 records · Page 28Linked to original sources
PubMed1985

Purification and characterization of the human neutrophil NADH-cytochrome b5 reductase.

NADH-cytochrome b5 reductase is the predominant NADH-diaphorase found in the human neutrophil (Blood 62:152, 1983). Although this reductase segregates with the light membranes of nitrogen-cavitated neutrophils separated on Percoll gradients (which include the plasma membrane markers alkaline phosphatase and NADPH-oxidase), it is approximately 95% excluded from plasma membrane-enriched phagocytic vacuoles. The reductase constitutes approximately 5% of the light membrane fraction FAD-flavoprotein (14.8 +/- 5.5 pmol/mg protein) and was found in equimolar concentration with a high potential b cytochrome also present in this light membrane fraction and tentatively identified as cytochrome b5. Isolation of the reductase from human neutrophils was accomplished by Triton X-114 solubilization of the light Percoll gradient membranes, followed by temperature-dependent phase separation and then affinity chromatography on AMP-Sepharose. The active preparation contained 1.3 mol FAD/mol protein, migrated on sodium dodecyl sulfate-polyacrylamide gels as a single band corresponding to an apparent mol wt of 45,000 daltons, exhibited a pl of 5.7 on chromatofocusing and was obtained in greater than 70% yield, with an overall purification of almost 900-fold. The purified enzyme was characterized by a high specificity for NADH as electron donor (Km = 6.4 mumol/L v Km greater than 1.6 mmol/L for NADPH) and exhibited a maximal turnover of ca. 30,000 min-1 at 22 degrees C with either ferricyanide or cytochrome b5 (Km = 10 nmol/L) as electron acceptor. Although the physical characterization and biochemical properties described here demonstrate that this neutrophil NADH b5 reductase is similar to the corresponding liver and erythrocyte enzymes, its unique function in the neutrophil has yet to be determined.

Cell Separation↗
PubMed1984

Vaccine prophylaxis of abattoir-associated Q fever.

Q fever is an important cause of morbidity in Australian meatworkers; recently there have been sharp outbreaks of Q fever in abattoirs in several states. In an attempt to control Q fever by vaccination, 924 nonimmune volunteers at two South Australian abattoirs were inoculated with one dose of a purified, formalin-inactivated, Coxiella burneti, Henzerling strain, phase 1 vaccine. Some 56% of workers in one abattoir, and 64% in the other, seroconverted after vaccination. In the 18 months after vaccination, no Q fever occurred in fully vaccinated subjects, whereas there were 34 cases in 1349 unvaccinated workers. Transient local reactions were noted in most vaccinated subjects; only a few had mild general reactions. No cases of vaccine-enhanced disease were observed. Vaccination of susceptible individuals with a purified C burneti phase 1 vaccine appears to be safe and effective in preventing Q fever in the abattoir.

Abattoirs↗
PubMed1984

The effects of chronic, small doses of melatonin given in the late afternoon on fatigue in man: a preliminary study.

In a double-blind cross-over study, melatonin (2 mg) or placebo, was administered daily for 4 weeks to 12 volunteers (10 men and 2 women) at 17.00 h during February and March. Self-rated fatigue (tiredness) was significantly increased in the evening during melatonin treatment. No other consistent effects on sleep ratings or mood parameters were observed and the dose was well tolerated.

Adult↗
PubMed1984

Lateral cephalothoracopagus: a case report.

A case of lateral cephalothoracopagus with posterior auricles is presented and compared with similar cases previously reported. This case is the first, to our knowledge, which exhibits both unequivocal lateral juncture of the faces and posterior auricles. Thus, it may represent a pattern of juncture intermediate between janiceps and lateral cephalothoracopagus.

Abnormalities, Multiple↗
PubMed1984

A cluster of cases of Mycobacterium chelonei keratitis associated with outpatient office procedures.

We studied three cases of keratitis caused by Mycobacterium chelonei, a nontuberculous mycobacterial species. The cases occurred in two women, 76 and 80 years old, and one man, 67 years old, treated as outpatients in the same office. One case followed suture removal and the other two occurred after posterior capsulotomy. Corneal lesions appeared within two to three weeks of trauma and were white, round infiltrates with indistinct margins and radiating projections. The lesions were found at all levels of the stroma and were associated with an epithelial defect. Anterior chamber reaction varied from a minimal response to a hypopyon. One patient responded to topical therapy with amikacin and erythromycin, but the other two patients required penetrating keratoplasties because of deep abscesses, which progressed toward the sclera despite therapy. These cases emphasized the possibility of rapidly growing nontuberculous mycobacteria producing serious ocular infections.

Aged↗
PubMed1984

Nephroblastoma in adults.

Nephroblastoma, or Wilms tumor, is the most common renal neoplasm in children and accounts for approximately a fifth of all malignant growths in this age group. However, the incidence of Wilms tumor in adults is much less common, with less than 200 cases having been reported in the literature. In addition, since there are at least 53 synonyms for this tumor an adequate computer search for articles relating to this subject is difficult. Because of the scarcity of this disease in adults definite treatment modalities have not been accepted thoroughly until recently. The rationale for the present treatment modalities is based largely on the National Wilms Tumor Study groups 1 to 3. We present radiologic and histologic findings of this tumor in 2 additional cases. The current treatment modalities, consisting of chemotherapy with or without adjunctive radiotherapy, are discussed.

Adult↗
PubMed1984

Malakoplakia mimicking carcinoma metastatic to lung.

Malakoplakia is a rare inflammatory disorder which infrequently involves sites outside of the lower genitourinary or gastrointestinal tract. We report a case of malakoplakia in which the patient presented with a left renal mass and bilateral pulmonary nodules suggestive of metastatic renal carcinoma. Postmortem cultures of the lesions grew E. coli; macrophages at both sites contained gram-negative bacilli and numerous Michaelis-Gutmann bodies. X-ray spectroscopic analysis of the bodies showed wide variation in calcium, phosphorus, and iron content, suggesting that Michaelis-Gutmann bodies were formed in part by the deposition of amorphous salts.

Diagnosis, Differential↗
PubMed1984

Perioperative transcutaneous O2 monitoring in the management of major peripheral arterial trauma.

The present report discusses the use of transcutaneous oxygen (PtcO2) monitoring in the perioperative management of a patient with two major peripheral arterial occlusions secondary to blunt trauma, during the performance of an external iliac artery thrombectomy and distal popliteal artery embolectomy. The injured limb PtcO2 was extremely low before surgery, but then increased to levels equal to and above contralateral limb PtcO2 a full 1 hour before skin closure. The injured limb PtcO2 correlated well with contralateral limb PtcO2 values after restoration of normal blood flow (r = 0.97). The ratio of injured limb PtcO2 to contralateral limb PtcO2 may be used to quantify the severity of arterial compromise in limb trauma and the adequacy of its treatment.

Adult↗
PubMed1984

Biochemical requirements for singlet oxygen production by purified human myeloperoxidase.

The myeloperoxidase (MPO)-hydrogen peroxide (H2O2)-halide systems were found to produce chemiluminescence at 1,268 nm, a characteristic emission band for singlet oxygen (1O2). The emission was enhanced by a factor of 29 +/- 5 in deuterium oxide and was inhibited by the 1O2 quenchers, histidine and azide ion. Inactivation of MPO with heat or with cyanide ion prevented light production. The combined weight of all data strongly supported the production of 1O2 by these enzyme systems. The amount of 1O2 produced was sensitive to the conditions employed. Under optimal conditions at pH 5, the MPO-H2O2-bromide (Br-) system produced 0.42 +/- 0.03 mol 1O2/mol H2O2 consumed, close to the theoretical value of 0.5 that was predicted by the reaction stoichiometry. In contrast, the MPO-H2O2-chloride (Cl-) system was much less efficient. The maximum yield of 1O2 was 0.09 +/- 0.02 mol/mol H2O2 consumed and required pH 4 and 5 mM H2O2. At higher pH, the 1O2 production rapidly decreased. The yield at pH 7 was 0.0004 +/- 0.0002 mol/mol H2O2 consumed. Enzyme inactivation was a major factor limiting the yield of 1O2 with both Cl- and Br-. While the MPO-H2O2-halide systems can efficiently produce 1O2, the conditions required are not physiologic, which suggests that the chemiluminescence of the stimulated neutrophil does not derive from 1O2 generated by a MPO mechanism.

Chloride Peroxidase↗
PubMed1983

Failure of repeated injection sclerotherapy to improve long-term survival after oesophageal variceal bleeding. A five-year prospective controlled clinical trial.

The role of sclerotherapy in long-term management after oesophageal variceal bleeding was assessed by comparing repeated sclerotherapy by means of a rigid oesophagoscope in 37 patients with control medical management in 38 patients. Varices were eradicated in 21 of the 22 patients analysed (95%) in the sclerotherapy group, but recurred in 13 of the 21 patients (average 21.5 months). Varices persisted in 13 of 14 surviving controls. The sclerotherapy patients had fewer recurrent bleeds than control patients (43 versus 73); the majority occurred before variceal eradication and were mild. However, there was no difference in survival in the two groups. The commonest cause of death was liver failure (37 patients). 32 complications occurred in 24 patients during 258 injections. Repeated sclerotherapy failed to improve survival in this trial, although varices were eradicated and recurrent variceal bleeds were prevented with adequate follow-up.

Acute Disease↗
PubMed1983

An immunotoxin of ricin A chain conjugated to thyroglobulin selectively suppresses the antithyroglobulin autoantibody response.

The autoantigen thyroglobulin has been conjugated with the A chain of the toxin ricin. In vitro this conjugated "immunotoxin" specifically suppressed the thyroglobulin autoantibody response of lymphocytes from patients with Hashimoto's thyroiditis. Neither total immunoglobulin synthesis nor the synthesis of autoantibody to thyroid microsomes by these lymphocytes was affected by the immunotoxin. The demonstration that an autoantigen coupled to a toxin can induce specific immunological unresponsiveness suggests that such immunotoxins could provide a novel and highly selective means for deleting autoantibody-secreting lymphocyte clones in patients with autoimmune disease.

Antitoxins↗
PubMed1983

Fatty acid synthesis and ketone body utilization by brown adipose tissue of the rat. Response to cold or nutritional state?

The effects of cold adaptation (exposure to 2-4 degrees C for 2-3 weeks) on the incorporation of 3H from 3H2O and of D-3-hydroxy [3- 14C]butyrate into fatty acid in vivo in interscapular brown adipose tissue of the rat were examined. Fatty acid synthesis, measured with 3H2O, was increased in brown adipose tissue of cold-adapted rats pair-fed ad libitum but not in cold-adapted rats pair-fed to the same food intake as rats maintained at 18-20 degrees C. Incorporation of D-3-hydroxybutyrate into fatty acid was increased in brown adipose tissue of cold-adapted rats, both when rats were fed ad libitum and when they were deprived of food for 48 h. Ketone bodies may be an important substrate for brown adipose tissue in the cold-adapted rat.

Acclimatization↗
PubMed1983

Central venous catheterization for parenteral nutrition. Experience at Groote Schuur Hospital.

The aim of this study was to determine the incidence of complications of catheterization for total parenteral nutrition (TPN) in patients of the Parenteral Nutrition Unit of Groote Schuur Hospital. During the 2-year study period, 218 central venous catheters were inserted in 170 patients. The preferred technique of percutaneous infraclavicular subclavian venepuncture with subsequent subcutaneous tunnelling using a silicone elastomere catheter is described. The incidence of major complications of catheter insertion was 4,5% (pneumothorax 4, subclavian artery puncture 6). There was a 2,7% incidence of catheter malpositioning (requiring repositioning) at initial insertion. The mean duration of catheterization was 12,9 days. During this period there was a 6,9% incidence of mechanical complications (occluded lines 13, extravascular infusion 2). Catheter-related sepsis was suspected in 37 cases (16,9%) and all these catheters were removed, but in only 7 cases (3,2%) was the sepsis proved to be catheter-related. There was no correlation between the duration of catheterization and the development of catheter-related sepsis. Furthermore, there was no increase in the incidence of catheter sepsis in patients with sepsis before catheterization.

Catheterization↗
PubMed1983

Videotape and verbal feedback in behavioral couple therapy: a review.

Reviewed the experimental evidence for the efficacy of videotape and verbal feedback in behavioral couple therapy; it is concluded that research to date does not permit definitive conclusions concerning the efficacy of either procedure. Studies on behavioral differences between happy and distressed couples also were summarized. The evidence indicates that it is, as yet, difficult to ascertain just how the communication behaviors of happy and distressed couples differ.

Adaptation, Psychological↗