Retrospective versus original information on diet: implications for epidemiological studies

The aim of this study was to evaluate the use of retrospective information on diet in relation to the information originally reported. Hospital controls (n = 131) who participated in a case-control study on diet and pancreatic cancer in Stockholm, Sweden, answered a second postal questionnaire four years later about their current and previous food consumption. The food consumption was dichotomized for the purpose of the analysis. In relation to the original information, the use of retrospective information overestimated previous food consumption among subjects with increased intake, while retrospective information underestimated previous food consumption among subjects with decreased intake. These tendencies were slightly more pronounced in the age group 60-79 years than in the age group 40-59 years. For subjects with unchanged food consumption, there was a high agreement between original and retrospective information. Considerable differential misclassification could be introduced in an epidemiological study if cases and non-cases differ with regard to changes in food consumption.     

A case report on a patient suffering from recurrent vomiting episodes, whose condition improved markedly during pregnancy and breast feeding

Background  

The normal physiology of the gastrointestinal tract has been only cursorily examined. Consequently, the pathophysiology of disturbances of the gastrointestinal functions is poorly known. Recurrent vomiting is one of many functional conditions for which it is difficult to find an explanation and to treat. In the following a case is described of a patient presenting with recurrent vomiting episodes, whose condition improved spontaneously during pregnancy and breast feeding.     

The usefulness of detailed information to patients with contact allergy

To find out if patients with contact allergy are helped by computerized information lists, a retrospective study was carried out on 58 patients with contact allergy to lanolin, traced through our local database DALUK. All were sent a questionnaire about their usage of the information list, clearance of their eczema, their education and other details. Clearance of the patient's eczema was found to correlate with use of the information list. It was also found that the effectiveness of the information depended on factors such as education, family circumstances, ethnic background and, most of all, how and where the information list was used.     

Fibrinolytic capacity in hemodialysis patients treated with recombinant human erythropoietin.

A major adverse effect of recombinant human erythropoietin (r-HuEPO) in hemodialyzed patients are thrombotic events. Several reports on platelet function during r-HuEPO treatment have been published but less is known about fibrinolysis. In the present study, the fibrinolytic capacity was studied in 20 patients on maintenance hemodialysis and treated with r-HuEPO. The patients were randomized into two groups and investigated in a crossover design. r-HuEPO was administered intravenously and subcutaneously in each group and was given for 3 months, respectively. Plasma tissue plasminogen activator (t-PA) and released t-PA remained unaffected by r-HuEPO in both groups throughout the study. Tissue plasminogen activator inhibitor (PAI) increased in a cyclic way reaching peak values 4-6 weeks after the start of investigation and again 4-6 weeks after changing therapy. The increase in PAI was significant in the two groups (0.025 > p > 0.01). Tissue plasminogen antigen was low in the uremic patients. The influence of r-HuEPO on this parameter was not investigated. Compensatory changes in plasma levels of factor XII procoagulant activity, activated protein C and of alpha 2-antiplasmin were not observed. Thrombotic events occurred in 4 patients at peak values of PAI. Six patients required an increase in heparin dose simultaneously with the increase in PAI. Thus, r-HuEPO seemed to affect the fibrinolytic capacity of uremic patients.     

Increased frequency of HLA-DPw2 in pauciarticular onset juvenile chronic arthritis

Thirty-six unrelated Danish patients with pauciarticular Juvenile Chronic Arthritis (PJCA) and 120 controls were typed for HLA-DPw1-w6 and the local specificity CDPHEI with bulk-expanded Primed Lymphocyte Typing (PLT) cells. The frequency of HLA-DPw2 was 52.8% in PJCA patients and 16.7% in controls (relative risk, RR = 4.5; P less than 0.001). The antigens HLA-Dw5 and/or Dw8 were present in 50% of the patients and in 21.3% of the controls (RR = 4.2; p less than 10(-3)). DPw2 was not associated (in linkage disequilibrium) with Dw5/w8 in patients or in controls, and the DP and D associations with PJCA were independent of each other. However, the combined presence of DPw2 and Dw5 and/or Dw8 gave a significantly higher risk of PJCA than each antigen alone indicating interaction of DP and DR gene products. PJCA is the first disease definitely found to be associated with a DP antigen.     

Solar heat load: heat balance during exercise in clothed subjects

Summary Six subjects exercised for 60 min on a cycle ergometer. Their backs were exposed to an artificial sun with a spectral distribution similar to sunlight and an intensity of 724 W m^–2. Each subject took part in four experiments in random order: wearing suits of polyester (insulation value = 0.5 clo), white (WP) or black (BP), or cotton (0.6 clo), white (WC) or black (BC). Measured by partitional calorimetry, the calculated heat losses and gains for the four conditions balanced within less than 10%. The differences between the short-wave radiation gains of subjects in white or black garments were small. This is due to the transparency of the white materials, which allows a larger percentage of the radiation to penetrate the clothing. The surface temperatures of the sun-exposed areas were very high, especially in the black suits. This promotes dry heat loss. Therefore the sweat loss in the black suits and the differences between the black and white clothes became relatively small. The physiological strain in steady-state exercise, as expressed by average heart rates, was 142 (WP), 154 (BP), 151 (WC), and 160 (BC) beats min^–1; the sweat losses were 649 (WP), 666 (BP), 704 (WC), and 808 (BC) g. For both of these measures values for white polyester were significantly less than those for black cotton.     

Vitamin B12 and folate status in acute geropsychiatric inpatients: affective and cognitive characteristics of a vitamin nondeficient population

This chart review study examined the serum vitamin B12 and folate status of 102 geriatric patients newly admitted to a private psychiatric hospital. Only 3.7% were B12 deficient and 1.3% were folate deficient; 4% were anemic. Nevertheless, those with below-median values of both vitamins had significantly lower Mini-Mental State scores than patients higher in one or both vitamins. Patients with "organic psychosis" with a negative family history for psychiatric disorder had significantly lower B12 levels than those with a positive family history. In major depression, folate levels correlated negatively with age at onset of psychiatric illness and length of hospitalization. These data suggest that (1) biochemically interrelated vitamins such as B12 and folate may exert both a separate and a concomitant influence on affect and cognition; (2) poorer vitamin status may contribute to certain geropsychiatric disorders that begin at a later age and lack a familial predisposition.     

Precorneal residence time in humans of sodium hyaluronate as measured by gamma scintigraphy

The aim of the present study was to quantify in man the distribution and clearance of two aqueous sodium hyaluronate (SH) solutions of 0.125% and 0.250% after the administration of 25 l onto the cornea. Isotonic phosphate buffer (PB) was used as a reference instillation. No systemic or local medication was given to the seven 18- to 30-year-old, healthy male volunteers. A detailed evaluation of the anterior segment of the eye, as well as a Schirmer test and a break-up time measurement, yielded results within the normal range. The clearance of 0.125% and 0.250% SH solutions radiolabelled with sodium pertechnetate Tc-99m was measured by gamma scintigraphy and compared with that of a PB solution tagged with the same radiolabel. There was no statistically significant difference between the quantities of 0.125% SH and PB solutions remaining in the precorneal space at 20 min (paired t-test,P=0.78,n=7). However, in comparing the 0.250% SH with the PB solution, we observed a statistically significant difference (P=0.01,n=7) in the amount remaining in the precorneal space after the same interval. Actually, 53% of the radiolabelled 0.250% SH solution remained on the cornea as compared with 30% for the 0.125% SH solution and 18.3% for the PB solution. These results suggest that an SH solution of 0.250% might have a prolonged residence time on the precorneal surface, and that SH could therefore be used as an additive in various drug-release systems for the eye.The present work was presented in part at the ARVO annual meeting in Sarasota in 1989