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Biomedical subjects

C Hansson

Publications and source records attributed to C Hansson.

At least 55 records · Page 3Linked to original sources

Identification of a substance, previously shown to enhance mitogenesis of human lymphocytes, as the acetamide of p-aminobenzoic acid.

We characterize here an arachidonic acid (AA)-derived metabolite previously found to have an adjuvant effect in phytohemagglutinin-induced mitogenesis of lymphocytes from mothers of newborn babies and from immunodeficient infants. We named the metabolite 'compound 4' due to its position in a thin-layer chromatography system developed for isolation of eicosanoids. The compound was originally found to be produced by peripheral blood mononuclear leukocytes and the T cell leukemia line Jurcat after long-term (18-24 h) incubation with [1-14C]AA. Compound 4 is also produced by lymphocytes, monocytes, platelets, thrombocytes, cultured fibroblasts and various types of malignant cell lines. We purified this metabolite by means of high pressure liquid chromatography with synchronous detection of radioactivity and measurement of ultraviolet-light absorption at 278 nm. Proton nuclear magnetic resonance spectroscopy and mass spectrometry with electron impact techniques demonstrated that compound 4 is not an eicosanoid, but is identical to p-acetamidobenzoic acid (PACBA). The cells synthesize PACBA from p-aminobenzoic acid and a two-carbon residue from AA.

4-Aminobenzoic Acid↗

Optimal treatment of venous (stasis) ulcers in elderly patients.

In elderly patients, even those with a typical venous (stasis) ulcer, coexisting conditions like peripheral arterial insufficiency and diabetes are very common. Therefore, all elderly patients with leg ulcers should have a complete medical assessment. The mainstay of treatment for venous ulcers is compression therapy, exercise and leg elevation at rest. Long term treatment with double bandages (zinc paste bandages and elastic compression), changed once weekly, is the recommended standard treatment in the elderly. Hydrocolloid dressings are also suitable for long term treatment in clean ulcers, and should be changed once or twice weekly and combined with compression. Sloughy, exudating ulcers might need redressing daily with a desloughing agent for a short period of time. The risk of sensitising patients with chronic leg ulcers is high and few topical preparations, with low antigenicity, should be used. Infection and ulcerated skin cancers should be ruled out in nonhealing ulcers if the patient complies with compression therapy. After healing, the patient should be advised to continue compression therapy with stockings to prevent recurrences. New noninvasive techniques for investigation of venous insufficiency can select patients suitable for venous surgery, but many elderly patients are not interested in surgery or have other ailments that prevent surgery.

Aged↗

Occupational exposure to hexahydrophthalic anhydride: air analysis, percutaneous absorption, and biological monitoring.

Urinary hexahydrophthalic acid (HHP acid) levels were determined in 20 workers occupationally exposed to hexahydrophthalic anhydride (HHPA) air levels of 11-220 micrograms/m3. The levels of HHP acid in urine increased rapidly during exposure and the decreases were also rapid after the end of exposure. The elimination half-time of HHP acid was 5 h, which was significantly longer than in experimentally exposed volunteers, possibly indicating distribution to more than one compartment. There was a close correlation between time-weighted average levels of HHPA in air and creatinine-adjusted levels of HHP acid in urine collected during the last 4 h of exposure (r = 0.90), indicating that determination of urinary HHP acid levels is suitable as a method for biological monitoring of HHPA exposure. An air level of 100 micrograms/m3 corresponded to a postshift urinary HHP acid level of ca. 900 nmol/mmol creatinine in subjects performing light work for 8 h. Percutaneous absorption of HHPA was studied by application of HHPA in petrolatum to the back skin of three volunteers. The excreted amounts of HHP acid in urine, as a fraction of the totally applied amount of HHPA, were within intervals of 1.4%-4.5%, 0.2%-1.3%, and 0%-0.4% respectively, indicating that the contribution from percutaneous absorption is of minor importance in a method for biological monitoring.

Adult↗

Stability of the mercaptobenzothiazole compounds.

An analytical quantitative high-pressure liquid chromatography (HPLC) method was developed for simultaneous determination of all mercaptobenzothiazole derivatives in the mercapto mix patch testing standard. The stability of the mercaptobenzothiazoles constituting the mercapto mix was studied both in petrolatum and in buffer solution at pH 6.5, with and without glutathione. In petrolatum vehicle, dibenzothiazyl disulfide was the dominant compound found in stored mercapto mix. In buffer solution at pH 6.5, 2-mercaptobenzothiazole and the sulfenamide derivatives morpholinyl mercaptobenzothiazole and N-cyclohexyl-2-benzothiazyl sulfenamide were converted into dibenzothiazyl disulfide. In the presence of glutathione, both the sulfenamide derivatives and the dibenzothiazyl disulfide were rapidly converted into 2-mercaptobenzothiazole. The findings explain the "cross-sensitivities" reported for the mercaptobenzothiazole group as a result of chemical reactions resulting in one main hapten. The use of a single substance for patch testing for mercaptobenzothiazole hypersensitivity is proposed.

Antimetabolites↗

Repeated treatment with lidocaine/prilocaine cream (EMLA) as a topical anaesthetic for the cleansing of venous leg ulcers. A controlled study.

Repeated topical analgesia with EMLA 5% cream prior to the cleansing of venous leg ulcers was studied. Patients were randomly allocated to a series of 8 treatments with EMLA (n = 22) or to a control group (n = 21). A thick layer of the cream was applied to the ulcers for 30 min. At each of the 8 treatments, local reactions were assessed on a 4-point scale and pain from ulcer cleansing on a visual analogue scale. At the first and the last treatment the area of the ulcer was determined by mapping, a sample for a bacterial culture was taken and the amount of dead tissue, slough and granulation tissue present was assessed. Treatment with EMLA for 30 min significantly decreased the pain from cleansing of the leg ulcers and the frequency of post-cleansing pain. The analgesic effect remained unchanged with successive treatments. Repeated treatment with EMLA in leg ulcers would appear to be safe, as indicated by the absence of any serious untoward events. No statistically significant differences in local reactions or adverse effects on granulation tissue, ulcer area or bacterial flora were observed in the EMLA-treated patients compared with the control patients.

Adult↗

Leg and foot ulcer prevalence and investigation of the peripheral arterial and venous circulation in a randomised elderly population. An epidemiological survey and clinical investigation.

Five thousand one hundred and forty questionnaires concerning leg ulcers were sent to a randomly selected population aged 65 years and older in Gothenburg in April 1989. The response rate was 89%. Ninety-seven individuals answered affirmatively, that they had leg ulcers, which corresponds to a prevalence of 2.15 +/- 0.42 per cent. These 97 individuals and the same number of controls were asked to come for a medical examination with tests of the peripheral circulation and an interview. Seventy-five (of the 97) were examined. Thirty-five had leg or foot ulcers caused by vascular insufficiency and/or diabetes and the true prevalence was estimated to be 1.02 +/- 0.29 per cent.

Aged↗

The stability of 5-S-cysteinyldopa and 6-hydroxy-5-methoxyindole-2-carboxylic acid in human urine.

5-S-cysteinyldopa and 6-hydroxy-5-methoxyindole-2-carboxylic acid are important intermediate metabolites in the formation of cutaneous melanin pigment. Since they both are serious candidates as markers of melanoma progression, their stability in urine has been investigated during storage at various conditions. The results show that storage at -20 degrees C is necessary. Both compounds are nonstable at room temperature, particularly if the urine was not acidified to pH 4-5. Reference levels were obtained from analysis of urine from 31 men and 40 women. The mean (SD) excretion of 5-S-cysteinyldopa was 32 (12.5) mumol/mol creatinine (women). Corresponding figures for 6H5MI2C were 23 (10.3) and 24 (8.1) mumol/mol creatinine for men and women respectively.

Adult↗

Lomefloxacin versus norfloxacin in the treatment of uncomplicated urinary tract infections: three-day versus seven-day treatment. The South Swedish Lolex Study Group.

This randomised, double-blind, multicenter study compared the safety and efficacy of lomefloxacin and norfloxacin in adult female outpatients with uncomplicated urinary tract infections. Patients were randomly assigned to one of 3 treatment groups: 400 mg lomefloxacin once daily for 3 days (L3), 400 mg lomefloxacin once daily for 7 days (L7), or 400 mg norfloxacin twice daily for 7 days (N7). A total of 703 patients (age 17-75 years) were enrolled at 21 investigative sites in southern Sweden. Clinical and microbiological evaluations were conducted at the start, 5-9 days and 3-4 weeks post therapy. Patients with quantitative urine cultures of > or = 10(4) CFU/ml of a susceptible pathogen were considered evaluable for efficacy. Escherichia coli and Staphylococcus saprophyticus were the most commonly isolated pathogens. In both L3 and L7 groups, 196 patients and in the N7 group 195 patients met the criteria for efficacy evaluation. At the 5-9 day post-treatment evaluation, 88% of the pathogens were eradicated in the L3 group, 93% in the L7 group and 93% in the N7 group. At the 3-4 week post-treatment evaluation, 81%, 82%, and 85% of urine cultures remained negative in the L3, L7, and N7 groups, respectively. No statistically significant differences between the 3 treatment groups were noted with the exception of eradication of S. saprophyticus, for which the 7 day courses were more effective at 4-9 days post treatment. No persistent pathogen developed resistance to the study drugs. All 3 treatment regimens were equally well tolerated, except for photosensitivity reactions, which were more frequently reported in patients in the lomefloxacin groups.

Adolescent↗