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Biomedical subjects

K Johansen

Publications and source records attributed to K Johansen.

At least 145 records · Page 8Linked to original sources
PubMed1986

Intestinal permeability in small children during and after rotavirus diarrhoea assessed with different-size polyethyleneglycols (PEG 400 and PEG 1000).

The permeability properties of the small intestinal mucosa was investigated in nine previously healthy children with acute diarrhoea due to rotavirus. The investigation was performed after intake of a mixture in water of polyethyleneglycol molecules (PEG 400 and 1000) ranging from 282 to 1250 dalton in molecular weight. The 6-h urinary recovery of the PEGs was determined with high performance liquid chromatography and used to assess the permeability characteristics of the intestine. The patients served as their own controls and were investigated in the same manner after recovery 3-5 weeks later. A significantly lower urinary recovery of PEG was noted for all molecular sizes (326-1206 dalton) during acute diarrhoea in comparison with the results obtained after recovery (p less than 0.001-0.1). There was also a relatively lesser change in the urinary recovery of larger PEG molecules during infection, as reflected by a higher recovery ratio between 1074 and 370 dalton PEGs. The results indicate profound changes in the permeability characteristics of the intestine during acute rotavirus diarrhoea.

Diarrhea, Infantile↗
PubMed1985

Insulin-gene flanking sequences, diabetes mellitus and atherosclerosis: a review.

A highly polymorphic locus flanking the human insulin gene contains two major size classes of DNA restriction fragments, which segregate in families as stable genetic elements. The L-allele, i.e. fragments with an average size of about 600 base-pairs seems to be a weak genetic marker for Type 1 (insulin-dependent) diabetes mellitus, whereas the U-allele, i.e. fragments of an average size of about 2500 base-pairs hitherto has been associated with Type 2 (non-insulin-dependent) diabetes mellitus and diabetic hypertriglyceridaemia. The most recent reports on this subject do not confirm an association between the U-allele and Type 2 diabetes. Our own studies indicate that the U-allele is a fairly strong marker for the development of atherosclerosis (relative risk for U-carriers 3.36). The putative functions of the polymorphic region in atherogenesis and the relation of this region to other genetic markers for atherosclerosis are not known.

Alleles↗
PubMed1985

Direct measurement of allantoic blood flow in the chicken, Gallus domesticus. Responses to alteration in ambient temperature and PO2.

A technique is described for direct measurement of allantoic blood flow in chicken embryos in situ using an electromagnetic flow meter. A branch of the allantoic artery was catheterized non-obstructively for simultaneous pressure measurement. In 15-day-old embryos at 39 degrees C the mean heart rate was 278 beats/min falling to 124 beats/min at 26 degrees C. Despite this fall in heart rate, blood flow fell only 10% from 4.4 ml/min at 39 degrees C to 4.0 ml/min at 26 degrees C. Mean allantoic blood pressure was similarly nearly unaffected by temperature. Allantoic blood flow was insignificantly altered by hyperoxic as well as hypoxic exposure (6% O2).

Allantois↗
PubMed1985

Hepatocellular carcinoma. A 5 year institutional experience.

Liver cancer is the most common of all malignancies worldwide, its incidence reaching almost epidemic proportions in some countries. However, its significance in North America has generally been underemphasized. In a 5 year period, hepatocellular carcinoma was diagnosed in 35 adult patients in our institution. Preexisting liver inflammation was present in 27 of the patients (77 percent). Although most patients had symptoms, they included only poorly defined pain or cachexia in most cases, and 10 patients (29 percent) were totally asymptomatic at the time of diagnosis. Five patients presented with hemoperitoneum due to intraabdominal tumor rupture. Examinations useful in confirming the diagnosis included alpha-fetoprotein determination, liver scan, and computerized tomographic scanning. Eight patients (23 percent) had associated visceral or other malignancies. The outlook was poor, with a mean survival of 5 months, and only two patients survived more than 1 year. Hepatocellular carcinoma is uncommon but not at all rare in the Pacific Northwest. It arises from chronic liver inflammation, is diagnosed late, and has a grim prognosis. Prevention of various forms of chronic liver inflammation, and mass serial screening of populations at high risk for the development of hepatocellular malignancy will probably have the greatest role in reducing the lethality of this disease.

Adult↗
PubMed1985

Is nasogastric suction necessary after elective colon resection?

It is commonly held that nasogastric suction is necessary after colon resection to prevent small and large bowel distension, wound complications, and anastomotic problems. In this retrospective study of 118 patients undergoing colon resection for malignancy or inflammatory disease, 83 underwent postoperative nasogastric suction and 35 did not. A wide variety of postoperative variables were evaluated in these two groups of patients and few differences were found. However, there were trends toward shorter postoperative hospital stays, and less abdominal distension, nausea, and vomiting could be discerned in the patients who did not undergo nasogastric suction. This retrospective study suggests that routine nasogastric suction may not be necessary or useful after elective colon resection.

Colon↗
PubMed1985

Bowel obstruction following omental patching of aortic grafts.

Omental pedicle flaps are commonly interposed between aortic reconstructions and the nearby small bowel to prevent erosion, graft infection, and aortoenteric fistula. While the utility of this technique is intuitive rather than proven, it is easily performed and complications from this approach have rarely been reported. We report two patients in whom clinically significant intestinal herniation beneath such an omental pedicle flap occurred, necessitating relief of acute small bowel obstruction. A simple method of preventing this complication is proposed.

Aged↗
PubMed1984

DNA sequences flanking the insulin gene on chromosome 11 confer risk of atherosclerosis.

The allelic frequency of DNA restriction fragments of a large size class (U alleles) in the polymorphic region flanking the 5'-end of the human insulin gene on chromosome 11 was 2 X 5 times higher in a group of patients with extensive atherosclerosis than in subjects in whom atherosclerosis could not be demonstrated by coronary arteriography and careful clinical examination. The U alleles apparently do not confer risk of atherosclerosis through conventional risk factors such as body weight or blood pressure or levels of blood glucose, triglycerides, cholesterol, or lipoproteins.

Adult↗
PubMed1984

Variations in renal threshold for glucose in Type 1 (insulin-dependent) diabetes mellitus.

The blood glucose/urinary glucose relationship was studied in 23 patients with Type 1 (insulin-dependent) diabetes. Glucose was infused intravenously in order to increase blood glucose concentration slowly and gradually. The renal threshold was recorded at the slightest trace of glycosuria and varied by a factor of 2 (from 6.0 to 14.3 mmol/l). The rise in blood glucose required to change the urinary output (0-1.1 mmol glucose/20 min) varied by a factor of 7 (1.1-7.6 mmol/l). The maximal rate of tubular glucose reabsorption varied by a factor of 2 (0.93-1.98 mmol/min). The renal threshold was negatively correlated with the creatinine clearance (r = -0.052, p less than 0.05), but was not correlated with diabetic control, age or duration of diabetes. The maximal rate of glucose reabsorption was negatively correlated with age (r = 0.47, p less than 0.05) and duration of diabetes (r = -0.54, p less than 0.05). In conclusion, urinary glucose excretion is dependent on both renal threshold and the splay and the slope of the blood glucose/urinary glucose excretion curve. Thus, the degree of glycosuria is of value as an index of diabetic control only when the blood glucose/urinary glucose relationship is known. The inverse correlation between renal threshold and creatinine clearance limits the usefulness of measuring glycosuria in patients with nephropathy.

Adolescent↗
PubMed1984

Incipient nephropathy in type 1 (insulin-dependent) diabetes.

Patients with Type 1 (insulin-dependent) diabetes without proteinuria were studied to define those patients who will later develop persistent proteinuria (more than 0.5 g protein/24 h). Two investigations were performed; 71 patients were studied longitudinally for 6 years and another 227 patients were studied cross-sectionally. All were less than 50 years of age and had developed diabetes before the age of 40 years. At entry into the study they had no proteinuria (Albustix method), had normal blood pressure and urinary albumin excretion rates less than 200 micrograms/min (normal less than or equal to 20 micrograms/min). The best predictor of persistent proteinuria or an albumin excretion rate greater than 200 micrograms/min was the initial urinary albumin excretion rate. During the longitudinal study, seven patients with an urinary albumin excretion rate of more than 70 micrograms/min at the start of the study developed persistent proteinuria or an albumin excretion rate greater than 200 micrograms/min. In contrast, only three out of the remaining 64 patients with urinary albumin excretion rate less than or equal to 70 micrograms/min developed urinary albumin excretion rate greater than 200 micrograms/min. Patients with an urinary albumin excretion rate greater than 70 micrograms/min are thus at risk of developing diabetic nephropathy. We designate this stage of renal involvement incipient nephropathy. Patients with incipient nephropathy were further characterized in the cross-sectional study. Compared with normoalbuminuric patients, patients with incipient nephropathy had increased systolic and diastolic blood pressure, but normal serum creatinine. The glomerular filtration rate was higher than normal in patients with incipient nephropathy though not different from that of normoalbuminuric patients.

Adolescent↗
PubMed1984

Ventilatory and circulatory changes during cold exposure in the Pekin duck Anas platyrhynchos.

Inspired ventilation (VI), O2 uptake (VO2), body temperature (TB), arterial blood pressure and arterio-venous differences in blood gases and pH were measured in ducks. Anas platyrhynchos, during exposure to variable ambient temperature (Ta) +20, 0 and -20 degrees C. A stable TB was maintained at all Ta's VO2 increased from 12.07 ml O2 (STPD) X kg-1 X min-1 at 20 degrees C to 28.95 ml O2 X kg-1 X min-1 at 20 degrees C. The ventilatory requirement (VI/VO2) changed from 0.468 L X mmol-1 at 20 degrees C to 0.322 L X mmol-1 at -20 degrees C corresponding to a change in overall O2-extraction from 28.5 to 41.4%. The increase in VI during cold exposure resulted from an increased tidal volume while breathing frequency was unchanged. This caused a smaller fraction of the total inspired air being dead space ventilation during cold exposure. The changed ventilatory requirement was largely the result of an increased parabronchial O2-extraction, whereas the altered ventilatory pattern accounted for a smaller part (21%) of the decreased ventilatory requirement. Arterial and venous O2 content and PaO2 changed little with cold exposure while PVO2 increased significantly. Calculated values for cardiac output increased from 173.7 ml X kg-1 X min-1 at +20 degrees C to 431.4 ml X kg-1 at -20 degrees C. From a thermoregulatory point of view it seems significant that the increased heat production during cold exposure is followed by an increased oxygen extraction in the lungs and in increased cardiac output, rather than by a further elevation of ventilation.

Animals↗
PubMed1984

Cerebral blood flow in the newborn infant: comparison of Doppler ultrasound and 133xenon clearance.

Two techniques of Doppler ultrasound examination, continuous-wave and range-gated, applied to the anterior cerebral artery and to the internal carotid artery, were compared with 133xenon clearance after intravenous injection. Thirty-two sets of measurements were obtained in 16 newborn infants. The pulsatility index, the mean flow velocity, and the end-diastolic flow velocity were read from the Doppler recordings. Mean cerebral blood flow was estimated from the 133Xe clearance curves. The correlation coefficients between the Doppler and the 133Xe measurements ranged from 0.41 to 0.82. In the subset of 16 first measurements in each infant, there were no statistically significant differences between the correlation coefficients of the various Doppler ultrasound variables, but the correlation coefficients were consistently lower for the pulsatility index than for mean flow velocity or end-diastolic flow velocity, and they were consistently higher for the range-gated than for the continuous-wave Doppler technique.

Blood Flow Velocity↗
PubMed1984

Thyroid-stimulating immunoglobulins in insulin-dependent diabetes mellitus.

Increased frequencies of thyroid diseases and thyroid microsomal antibodies have been observed in insulin-dependent diabetes mellitus. However, the exact prevalence of thyroid-stimulating immunoglobulins has not been established. In the present study these antibodies were measured by both a radioreceptor and an adenylate-cyclase stimulation assay. In forty-six patients with insulin-dependent diabetes mellitus without endogeneous insulin production (C-peptide concentration less than or equal to 0.06 nmol 1(-1)) the receptor assay was positive in ten and the stimulation assay in fifteen patients. The immunoglobulins of four patients inhibited the adenylate cyclase, and one of these was positive in the receptor assay. In nine patients with post-prandial C-peptide 0.07-0.19 nmol 1(-1), five had adenylate-cyclase-stimulating antibodies, while none were positive in the receptor assay. Thyroid hormones and thyrotropin concentrations were not different in the forty-six patients without endogenous insulin production with thyroid-stimulating immunoglobulins compared with patients without these antibodies. Patients with thyroid-stimulating immunoglobulins required a daily median amount of 0.71 IE of insulin kg-1 compared to median of 0.57 IE kg-1 in patients without these antibodies (P less than 0.03), despite a similar degree of diabetic regulation. The level of tri-iodothyronine was correlated to the antibody level in patients with adenylate-cyclase-stimulating antibodies. While the prognostic and possibly pathogenetic importance of these antibodies in Graves' disease have been established, their significance in insulin-dependent diabetes mellitus remains to be demonstrated.

Adenylyl Cyclases↗
PubMed1984

Absorption of soluble and isophane semi-synthetic human and porcine insulin in insulin-dependent diabetic subjects.

A double-blind cross-over study of the sc absorption of radiolabelled semi-synthetic human (SHI) and purified porcine (PPI) insulin was made. Absorption of both isophane (n = 10) and soluble insulin (n = 8) was studied. There was no significant difference between the disappearance from the injection site, the plasma free insulin concentrations, or blood glucose levels after sc injection of the isophane preparations. A faster disappearance of the soluble SHI (as judged from T/50 and AUC) was found (both P-values less than 0.01). However, no difference was observed between the plasma insulin concentrations at any time point (P less than 0.05). Blood glucose levels showed no statistical differences between the two soluble preparations. The data indicate minor differences between the pharmacokinetics of SHI and PPI, but these seem of no clinical importance.

Absorption↗
PubMed1984

Acarbose treatment of sulfonylurea-treated non-insulin dependent diabetics. A double-blind cross-over comparison of an alpha-glucosidase inhibitor with metformin.

The postprandial blood glucose rise after a standard meal in six non-insulin dependent diabetics was significantly lower when acarbose 200 mg was taken together with the meal than without acarbose. Eight weeks acarbose treatment (300 mg), however, did not change fasting blood glucose. The effect of four weeks administration of the alpha-glucosidase inhibitor acarbose (300 mg) on diabetes regulation in another ten non-insulin dependent diabetics was compared with metformin (500 mg) in a double-blind cross-over study. Acarbose lowered postprandial blood glucose level from 11.5 +/- 4.2 to 8.9 +/- 1.8 mmol/l (p less than 0.02) and haemoglobin Alc from 8.1 +/- 1.8 to 7.7 +/- 1.7% (p less than 0.05). Urinary glucose was also decreased. Metformin did not significantly change postprandial blood glucose, haemoglobin A1c and urinary glucose excretion with the prescribed dose. The postprandial blood glucose and haemoglobin A1c after 4 weeks of treatment with acarbose and of metformin did not differ significantly. Side-effects of both drugs were mild and mainly gastrointestinal, but the frequency of side-effects was not different.

Acarbose↗