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Biomedical subjects

B Lund

Publications and source records attributed to B Lund.

288 records · Page 16Linked to original sources

Long-term changes in bone mass after partial gastrectomy in a well-defined population and its relation to tobacco and alcohol consumption.

We studied the long-term effect of partial gastrectomy on bone metabolism in a well defined population of gastrectomized patients compared to an age- and sex-matched group with unoperated peptic ulcers (controls). We selected 61 individuals between 61 and 70 years old at the time of investigation who had been operated on at the same surgical department an average of 20 years earlier. Compared to unoperated ulcer patients, we found reduced bone mass of the distal forearm in the operated groups. The serum level of calcidiol was significantly reduced in Billroth I (BI) operated women and insignificantly lower in the other operated groups. In men, ionized and total calcium was reduced, and 24-hour excretion of hydroxyproline in the urine as increased (p < 0.05). Biochemical signs of osteomalacia were found in one gastrectomized patient only. There were no significant differences between operated and unoperated patients in serum levels of alkaline phosphatases, iPTH, calcitriol, or the 24-hour urine calcium/creatinine excretion, even though there was a trend toward lower 24-hour urine calcium/creatinine ratio and increased levels in iPTH in the operated groups. There was no correlation between the daily alcohol consumption or cumulative tobacco consumption and bone mineral content in each group. Gastrectomized women smoked much more than control women, and smoking may be a determinant factor for the bone loss, as it is in healthy persons. Operated patients had a lower intake of milk products. All patients were exposed to sunlight for more than 3 hours/week. It is suggested that osteopenia after gastrectomy might be caused by calcium depletion rather than lack of vitamin D. The consumption of tobacco but not of alcohol was connected to bone loss.

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Vitamin D metabolism in insulin-dependent diabetes mellitus.

A significant loss of bone has been observed in diabetes mellitus. The pathogenesis is unknown, but an impairment of vitamin D metabolism might be involved. Consequently, we have studied vitamin D metabolism in five groups of insulin-dependent diabetic patients. Significantly reduced levels of serum 25(OH)D were seen only in patients with diabetic nephropathy. The serum levels of 1,25 (OH)2D were reduced only in diabetic ketoacidosis but normalized during recovery. It is concluded that vitamin D metabolism is largely normal in adult insulin-dependent diabetes, and it seems unlikely that a disturbance of the vitamin D metabolism can explain the bone loss in the ordinarily controlled diabetics.

24,25-Dihydroxyvitamin D 3↗

Localization of the receptor-binding protein adhesin at the tip of the bacterial pilus.

Strains of the bacterium Escherichia coli that cause infections of the human urinary tract produce so-called Pap-pili, which are hair-like appendages consisting of about 10(3) helically arranged subunits of the protein PapA. These pili mediate binding to digalactoside-containing glycolipids present on the epithelial cells which line the urinary tract. Recently, it has been suggested that three proteins, PapE, PapF and PapG, are responsible for this binding. In the absence of PapA, non-piliated bacteria are formed which nonetheless exhibit binding, showing that the bulk of the pilus is not essential for binding. Although pili can form without PapF and PapG, such pili are unable to bind to the digalactoside. The protein PapG mediates binding specificity in trans-complementation experiments, so this protein is the digalactoside-specific adhesin. Using immuno-electron microscopy we have found that Pap-pili are heteropolymers composed of the major pilin, PapA, the minor pilins, PapE and PapF, and the adhesin, PapG. The last three proteins are located at the tip of the pilus.

Adhesins, Escherichia coli↗

Radiation treatment of giant-cell tumour of bone (osteoclastoma).

Ten patients with giant cell tumours of the bone were treated by radiation therapy. Indications were non-radical primary surgery in 8 cases and recurring lesions in 2. Tumour doses ranged from 23 to 75 Gy delivered with supervoltage equipment in 8 cases. There were 3 recurrences after radiation therapy, all occurring in patients with tumor doses less than 39 Gy; 2 of these had received orthovoltage therapy and 2 died later from lung metastases. Modern supervoltage irradiation is probably as effective as surgery which is nevertheless recommended in operable cases.

Adult↗

The Carotene and Retinol Efficacy Trial (CARET) to prevent lung cancer in high-risk populations: pilot study with asbestos-exposed workers.

Pilot studies are an essential component for major chemoprevention trials. Prior to initiating the multicenter Carotene and Retinol Efficacy Trial to assess the effectiveness of beta-carotene and retinol for preventing lung cancer, we conducted pilot studies in Seattle between 1985 and 1988 in two high risk populations: current and former heavy smokers and asbestos-exposed workers. The Asbestos Workers Pilot Study for the Carotene and Retinol Efficacy Trial demonstrated that recruitment of asbestos-exposed participants with relevant risk factors was feasible from identified sources. We documented negligible toxicity and high adherence with the protocol, schedule, and intervention. Results from the pilot led to extension of the placebo run-in period, changes in the eligibility criteria, improvements in recruitment strategies and scheduling, elimination of stratification by risk factors in randomization, modifications of study vitamin dosage and of side effects monitoring, and refinement of trial design parameters for Carotene and Retinol Efficacy Trial. The Smokers Pilot is reported in the accompanying article (G. E. Goodman et al., Cancer Epidemiol., Biomarkers & Prev., 2: 389-396, 1993).

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The Carotene and Retinol Efficacy Trial (CARET) to prevent lung cancer in high-risk populations: pilot study with cigarette smokers.

In preparation for a phase IV lung cancer chemoprevention trial, we conducted a pilot trial of beta-carotene and retinol in high-risk smokers. Eligibility criteria were ages of 50-69 years, a smoking history of at least 20 pack-years, and either being a current smoker or having quit within the past 6 years. Participants were recruited by mailing an interest survey to 29,928 age-selected members of King County Medical Blue Shield. We randomized 1,029 women and men to one of four intervention arms: placebo, retinol, 25,000 international units/day; beta-carotene, 30 mg/day; or retinol plus beta-carotene. Participants were followed for side effects and adherence every 2 months either by a telephone call or a clinic visit. Blood was sampled for retinoid, carotenoid, and liver function analyses annually. beta-carotene and retinol were well tolerated during the follow-up period, which had a median of 1.5 years and a maximum of 3.3 years. Yellowing of the skin was seen in both beta-carotene arms. No differences were seen among arms or over time in incidence or severity of the other 15 monitored symptoms and signs or in serum liver function tests. Adherence was good: 83% of participants remained active on study at 1 year and 75% at 2 years. Serum beta-carotene increased from a prerandomization median concentration of 170 to 2100 ng/ml after 4 months of supplementation, and retinyl palmitate median levels more than tripled.(ABSTRACT TRUNCATED AT 250 WORDS)

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