Escherichia coli biofilm formation and recurrences of urinary tract infections in children.

It has been suggested that biofilm formation by uropathogenic Escherichia coli (UPEC) isolates is associated with recurrence and persistence of urinary tract infection (UTI). We compared the in vitro biofilm formation of UPEC isolates from children with acute or recurrent UTI. Employing 206 consecutive clinical UPEC isolates from children with proven UTI, i.e., pyelonephritis (n = 78), recurrent pyelonephritis (n = 10), cystitis (n = 84) or recurrent cystitis (n = 34), we applied 1 % crystal violet staining to polystyrene microtitre plates at 72 h and measured the optical density (OD) values. The method had been validated to measure biofilm formation against confocal laser scanning microscopy and scanning electron microscopy. The OD values were lower in the recurrent cystitis group than in the other groups (mean OD 0.36, SD 0.21 vs mean 0.47, SD 0.36, P = 0.04) and higher in the recurrent pyelonephritis group than in the other groups (mean OD 0.69, SD 0.33 vs mean OD 0.44, SD 0.34, P = 0.006) indicating biofilm formation of strains causing recurrent pyelonephritis. It appears that the properties of UPEC isolates required for effective biofilm growth on an abiotic surface are important for recurrent pyelonephritis, but not for recurrent cystitis. It would be valuable in the future to analyze whether the biofilm properties of E. coli observed in vitro predict a slower clinical response to antimicrobial treatment and increased renal scar formation after UTI.

Diarrea crónica como manifestación de tumor neuroendocrino metastásico / Chronic diarrhea as presenting symptom for a metastasic neuroendocrine tumor

Se presenta el caso de una paciente femenina de 74 años de edad, con cuadro de diarrea acuosa severa, hipocalemia importante y metástasis hepáticas, documentándose en su autopsia un tumor neuroendocrino primario en el páncreas como causa de su cuadro. Se presenta una revisión de la literatura sobre los tumores neuroendocrinos del páncreas con énfasis en el VIPoma, por su correspondencia con el caso de esta paciente.

The organic anion transport polypeptide 1d1 (Oatp1d1) mediates hepatocellular uptake of phalloidin and microcystin into skate liver.

Organic anion transporting polypeptides (rodent Oatp; human OATP) mediate cellular uptake of numerous organic compounds including xenobiotic toxins into mammalian hepatocytes. In the little skate Leucoraja erinacea a liver-specific Oatp (Oatp1d1, also called sOatp) has been identified and suggested to represent an evolutionarily ancient precursor of the mammalian liver OATP1B1 (human), Oatp1b2 (rat), and OATP1B3 (human). The present study tested whether Oatp1d1 shares functional transport activity of the xenobiotic oligopeptide toxins phalloidin and microcystin with the mammalian liver Oatps/OATPs. The phalloidin analogue [(3)H]-demethylphalloin was taken up into skate hepatocytes with high affinity (Km approximately 0.4 microM), and uptake could be inhibited by phalloidin and a variety of typical Oatp/OATP substrates such as bromosulfophthalein, bile salts, estrone-3-sulfate, cyclosporine A and high concentrations of microcystin-LR (Ki approximately 150 microM). When expressed in Xenopus laevis oocytes Oatp1d1 increased uptake of demethylphalloin (Km approximately 2.2 microM) and microcystin-LR (Km approximately 27 microM) 2- to 3-fold over water-injected oocytes, whereas the alternative skate liver organic anion transporter, the dimeric Ostalpha/beta, exhibited no phalloidin and only minor microcystin-LR transport. Also, the closest mammalian Oatp1d1 orthologue, the human brain and testis OATP1C1, did not show any phalloidin transport activity. These results demonstrate that the evolutionarily ancient Oatp1d1 is able to mediate uptake of cyclic oligopeptide toxins into skate liver. The findings support the notion that Oatp1d1 is a precursor of the liver-specific mammalian Oatps/OATPs and that its transport properties are closely associated with certain forms of toxic liver injury such as for example protein phosphatase inhibition by the water-borne toxin microcystin.

Epidemiological and clinical studies on insulin resistance and diabetes.

In Uppsala, extensive epidemiological and clinical studies on insulin resistance and diabetes have been ongoing for the past 30 years. A prospective cohort study of men born 1920-24, living in Uppsala County, was initiated during 1969-74 (the Uppsala Longitudinal Study of Adult Men, ULSAM). Risk factors for cardiovascular disease were examined in 2,322 men, and re-examinations have been performed every 10 years. At the first follow-up, when the men were 60 years old, insulin resistance was found to be a risk factor for development of hypertension and diabetes. In addition, treatment with antihypertensive medication was an independent risk factor for development of diabetes. These findings resulted in a series of clinical studies on metabolic effects of antihypertensive agents. At the second follow-up, when the men were 70 years old, the development of hypertension and diabetes was once again in focus, but at this time, cross-sectional and prospective studies of other cardiovascular determinants, such as circadian blood pressure pattern, left ventricular geometry and function, muscle morphology, ion status, fibrinolysis and cognitive function, were also performed. The cohort has furthermore been linked to the Swedish census and hospital discharge and cause of death registries, it has been used for studies on relationships between birth weight and cardiovascular disease, and genetic analyses have been performed, taking advantage of the long observation time obtained in this cohort. The cohort is currently being re-examined for the third time, and will hopefully continue to provide valuable information on the epidemiology of diabetes and cardiovascular disease in the future.

The haemodynamic response to hyperinsulinaemia in hypertensive subjects.

In order to study if the vasodilatory action of insulin is impaired in essential hypertension, 24 untreated patients were challenged with a 2 h euglycaemic hyperinsulinaemic clamp (56 E/m2). Cardiac index (CI) was measured by thoracic impedance cardiography and leg blood flow (LBF) by Doppler ultrasound. During the clamp procedure a significant decline in blood pressure was seen (3.0-5.6% over 120 min, P < 0.001). However, no significant effects on ejection fraction (+6 +/- 8 s.d.%), CI (-1 +/- 2%), heart rate (+2 +/- 1%) or total peripheral resistance (TPRI, -0.5 +/- 2%) were found. LBF increased by 22 +/- 35% (P < 0.005). These haemodynamic effects of insulin were not related to age, sex, body mass index, blood pressure or the insulin-mediated glucose uptake during the clamp. In conclusion, insulin increased LBF, but no changes in CI and TPRI were seen in the hypertensive patients. Furthermore, no association between the ability of insulin to induce vasodilatation and to promote glucose uptake was seen.

Local vasodilatation with metacholine, but not with nitroprusside, increases forearm glucose uptake.

Insulin is known to increase blood flow in parallel to glucose uptake in skeletal muscle. However, it is not known if an increase in blood flow by itself is associated with an increase in glucose uptake in the absence of hyperinsulinemia. To investigate further this matter, the effect of increased blood flow on forearm glucose uptake was studied in the fasting state during intra-arterial infusions of two different vasodilators, metacholine and nitroprusside, in 19 hypertensive subjects. Both metacholine (4 microg/min) and nitroprusside (10 microg/min) increased resting forearm blood flow, measured by venous occlusion plethysmography, to a similar degree (180 % and 170 %, respectively, p<0.0001 for both). However, metacholine infusion increased the forearm glucose uptake from 2.0+/-0.9 (S.D.) during rest to 5.5+/-3.0 umol/min/100 ml tissue (p<0.0001), while no significant change in glucose uptake was seen during nitroprusside infusion (2.3+/-1.4 micromol/min/100 ml tissue). In conclusion, vasodilatation induced by metacholine, but not by nitroprusside, increased glucose uptake in the forearm of hypertensive patients. Thus, an increase in forearm blood flow does not necessarily improve glucose uptake in the forearm during the fasting state.

Clenbuterol-induced insulin resistance in calves measured by hyperinsulinemic, euglycemic clamp technique.

Hyperinsulinemic, euglycemic clamp tests were performed on calves before and after clenbuterol treatment. Clenbuterol was given as 2 intramuscular injections with an interval of about 12 h. The dose used was 1 microgram/kg b.w. The treatment resulted in increased plasma levels of insulin and glucose. The results of the clamp tests showed that clenbuterol induced a transient decrease in insulin sensitivity. Both insulin mediated glucose disposal (M), expressed as mumol/kg live b.w./min. and the M/I-index (M divided by the average insulin concentration at steady state) were significantly reduced after treatment. The effect of clenbuterol on carbohydrate metabolism seemed to be rather short-lived, since significant changes occurred only in animals treated 5-6 h prior to the test. According to the literature, the metabolic effects of clenbuterol have been studied only after the high doses used for growth promoting purposes. The results from the present study showed that similar changes occur also after doses at the therapeutic level. The hyperinsulinemic, euglycemic clamp test was considered to be a valuable tool for the study of insulin sensitivity in cattle.

Regression of left ventricular wall thickness during ACE-inhibitor treatment of essential hypertension is associated with an increase in insulin mediated skeletal muscle blood flow.

UNLABELLED: Left ventricular hypertrophy (LVH) has been associated with insulin resistance, a condition with an impaired insulin-mediated vasodilation in skeletal muscle. ACE-inhibitors have been reported to be superior to most other antihypertensive drugs in inducing a regression of LVH. In a double-blind study with parallel groups, 50 patients with essential hypertension were randomized to treatment with either fosinopril (20 mg o.d.) or atenolol (50 mg o.d.) for 12-16 weeks. Left ventricle wall thickness (LVWT, defined as the sum of interventricular septum and posterior wall), diastolic function (represented by the ratio between the E-wave and the A-wave of mitral blood flow) and femoral artery blood flow (FBF) were evaluated using ultrasonic measurements. FBF was measured at normoinsulinemia and after 2 h of euglycemic hyperinsulinemia. Before treatment, the insulin-induced increase in FBF was inversely related to the LVWT (r = -0.52, p < 0.02). The reduction in ambulatory 24-h SBP/DBP was 13/9 mmHg for fosinopril and 15/14 for atenolol, ambulatory DBP being significantly more reduced by atenolol (p = 0.03 for difference in treatment effect). However, only fosinopril treatment resulted in a significant reduction in LVWT (from 20.5 mm to 19.4 mm, p < 0.05). The degree of reduction in LVWT was related to the increase in FBF in the fosinopril group (r = -0.45, p < 0.05). For fosinopril (but not for atenolol), there was a positive relationship between the change in E/A ratio and the change in femoral artery stroke volume (r = 0.80, p < 0.01). CONCLUSION: Impaired insulin-induced stimulation of leg blood flow was related to an increased LVWT. Furthermore, during fosinopril treatment, regression of LVWT was associated with enhanced skeletal muscle blood flow during hyperinsulinemia. This indicates that impaired peripheral blood flow (and thereby increased afterload) may be a possible mechanism explaining the previously found association between insulin resistance and cardiovascular hypertrophy.

The effect of euglucaemic hyperinsulinaemia on forearm blood flow and glucose uptake in the human forearm.

Insulin-mediated stimulation of blood flow to skeletal muscle has been proposed to be of major importance for insulin-mediated glucose uptake. The aim of this study was to investigate the relative importance of blood flow and glucose extraction as determinants of insulin-mediated glucose uptake in the human forearm. Forearm blood flow (FBF), glucose extraction and oxygen consumption were evaluated for 100 min during the euglycaemic hyperinsulinaemic clamp (92 mU/l) in nine healthy subjects. FBF was measured by venous occlusion plethysmography. Forearm glucose uptake increased sevenfold during the hyperinsulinaemia (P<0.001). Forearm glucose extraction showed a minor increase during the first 10 min of hyperinsulinaemia, but the most marked increase took place between 10 and 20 min (+170%). Thereafter, only a minor further increase was seen. During the first 10 min of hyperinsulinaemia FBF was unchanged. Thereafter, FBF increased steadily to a plateau reached after 60 min (+50%, P<0.001). A close relationship between whole body glucose uptake and FBF was seen at the end of the clamp (r = 0.75, P<0.02), but at this time the relationship between whole body glucose uptake and forearm glucose extraction was not significant. The modest increase in O2 consumption seen at the beginning of the clamp (+19%) was not related to FBF during the early phase of the clamp. In conclusion, the early course of insulin-mediated glucose uptake in the human forearm was mainly due to an increase in glucose extraction. However, with time the insulin-mediated increase in blood flow increased in importance and after 100 min of hyperinsulinaemia FBF was the major determinant of glucose uptake.

Circulating angiotensin converting enzyme levels are increased in concentric, but not eccentric, left ventricular hypertrophy in elderly men.

OBJECTIVE: To study the cross-sectional relationship between circulating angiotensin converting enzyme (ACE) activity and echocardiographically determined left ventricular geometry in a study of 380 70-year-old men participating in a health-survey reexamination and 50 patients with hypertension. METHODS: Two-dimensional guided M-mode and Doppler echocardiography. Fluorometric assay of serum ACE activity. RESULTS: The serum ACE activity was higher in the elderly men with left ventricular concentric hypertrophy than it was in men with normal geometry and left ventricular eccentric hypertrophy (32, 27, and 26 U/l, respectively, P < 0.01 for both comparisons before and after adjustment for the 24 h mean arterial pressure, body mass index, and use of antihypertensive medication). The serum ACE activity correlated with the thickness of the left ventricular interventricular septum (r = 0.12, P = 0.0095), the left ventricular relative wall thickness (r = 0.13, P = 0.0053 ), and the total peripheral resistance (r = 0.16, P = 0.0034), but not with the left ventricular mass (r = -0.039, P = 0.45) of these elderly men. The serum ACE activity in the hypertensive patients also correlated with the left ventricular interventricular septum thickness (r = 0.34, P = 0.020) independently of the 24 h mean arterial blood pressure, age, sex, body mass index, and insulin sensitivity. CONCLUSION: Levels of serum ACE activity are associated with left ventricular geometry.

Serum levels of parathyroid hormone are related to the mortality and severity of illness in patients in the emergency department.

Hypocalcaemia is a common finding in intensive care patients. In addition, raised levels of parathyroid hormone (PTH) have been described. The explanation and clinical importance of these findings are yet to be revealed. To investigate the occurrence of hypocalcaemia and elevated PTH levels and their relationship to morality and the severity of disease, serum levels of PTH, ionized calcium (Ca2+) and the cytokines interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-alpha) were measured on arrival in the emergency department in a broad spectrum of 140 acutely ill patients patients suffering from common diseases such as stroke, acute abdominal disorders, obstructive lung diseases, heart failure, acute myocardial infarction, angina pectoris, trauma and infectious diseases. A score (APACHE II) was calculated to assess the severity of disease. Elevated PTH levels (> 55 pg ml-1) were seen in 16% of the patients, being most frequent in patients with myocardial infarction (28%) and congestive heart failure (42%). The levels were significantly correlated with the APACHE II score (r = 0.48, P < 0.0001) and with the length of stay in hospital (r = 0.26, P < 0.002). PTH was also significantly (P < 0.03) elevated in non-survivors compared with survivors and was found to be a stronger predictor of mortality (P < 0.01) than the APACHE II score (P < 0.02) in Cox's proportional hazard analysis. No close relationships were found between the cytokine levels and the indices of calcium metabolism. In conclusion, a rise in serum levels of PTH was common and related to the severity of disease and mortality in a mixed emergency department population.

Vitamin D is related to blood pressure and other cardiovascular risk factors in middle-aged men.

A previous study has shown that serum levels of the active vitamin D metabolite 1,25-(OH)2-vitamin D were inversely related to blood pressure levels while the prohormone 25-OH-vitamin D was found to be related to insulin metabolism. Also other clinical and experimental data support the view that vitamin D metabolism is involved in blood pressure regulation and other metabolic processes. The present study was conducted in order to see if the above mentioned relationships between the vitamin D endocrine system and blood pressure, as well as other cardiovascular risk factors, could be found in a cross-section population-based study. Serum levels of 1,25-(OH)2-vitamin D, 25-OH-vitamin D, and blood pressure were therefore measured in 34 middle-aged men and metabolic cardiovascular risk factors were evaluated by means of intravenous glucose and fat tolerance tests, euglycemic hyperinsulinemic clamp, lipoprotein measurements, and lipoprotein lipase activity determinations. Serum levels of 1,25-(OH)2-vitamin D were found to be inversely correlated to the blood pressure (r = -0.42, P < .02), VLDL triglycerides (r = -0.47, P < .005), and to triglyceride removal at the intravenous fat tolerance test (r = 0.34, P < .05), while serum levels of 25-OH-vitamin D were correlated to fasting insulin (r = -0.35, P < .05), insulin sensitivity during clamp (r = 0.54, P < .001), and lipoprotein lipase activity both in adiposal tissue (r = 0.48, P < .005) and skeletal muscle (r = 0.38, P < .03).(ABSTRACT TRUNCATED AT 250 WORDS)

Is insulin resistance a predictor of the blood pressure response to anti-hypertensive treatment?

It is a general impression that the blood pressure (BP) response during monotherapy in hypertensive subjects is highly variable. As decreased insulin sensitivity is a frequent finding in hypertensive patients, the following study was performed to evaluate if the degree of insulin sensitivity could predict the BP response to different types of anti-hypertensive treatments. Insulin sensitivity was evaluated by the hyperinsulinaemic euglycaemic clamp technique before initiation of treatment with beta-adrenergic blockers (n = 181), thiazide diuretics (n = 60), ACE inhibitors (n = 73), non-dihydropyridine calcium antagonists (n = 38), dihydropyridine calcium antagonists (n = 26) or alpha-1 antagonists (n = 39) over periods of 3-6 months in hypertensive patients. The proportion of poor responders, defined as a reduction in the diastolic blood pressure (DBP) of < 3 mm Hg ranged between 8% and 30% in the different groups despite similar pretreatment DBPs (100-102 mm Hg). A decreased pretreatment insulin sensitivity was related to a poor DBP treatment response in the thiazide-treated group only (r = -0.33, P < 0.05). In this group also obesity, as evaluated by body mass index (BMI), was associated with a poor BP response (r = 0.28, P < 0.05), while obesity was a predictor of a favourable reduction in DBP in the group treated with non-dihydropyridine calcium antagonists (r = -0.34, P < 0.05). These associations were still significant when pretreatment DBP was taken into account in multiple regression analysis. Neither age nor sex were found to be significant predictors of BP response in any of the treatment groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Left ventricular hypertrophy in hypertension is associated with the insulin resistance metabolic syndrome.

OBJECTIVE: To investigate whether left ventricular hypertrophy is associated with the insulin resistance syndrome. METHODS: Fifty patients with untreated hypertension were evaluated by recording office blood pressure during regular antihypertensive treatment and 24-h ambulatory blood pressure and office blood pressure after 4-6 weeks on placebo, echocardiography with M-mode measurements of left ventricular wall thickness and pulsed-wave Doppler measurements of mitral flow in diastole and the hyperinsulinaemic euglycaemic clamp, for determination of insulin sensitivity. RESULTS: The left ventricular wall thickness was found to be significantly related to blood pressure [r = 0.44, P < 0.004 for 24-h ambulatory systolic blood pressure (SBP)], fasting insulin level (r = 0.32, P < 0.03) and haematocrit level (r = 0.37, P < 0.009) and inversely related to insulin sensitivity (r = -0.59, P < 0.0001). Multiple regression analysis with these relationships together with confounding factors age, sex, body mass index and waist: hip ratio as independent variables showed insulin sensitivity to be the only significant variable, explaining 43% of the variation in left ventricular wall thickness, whereas 24-h ambulatory SBP explained a further 7%. Left ventricular diastolic filling, as evaluated by the mitral Doppler early: atrial ratio, was significantly correlated with insulin sensitivity (r = 0.42, P < 0.003) and inversely related to blood pressure (r = -0.41, P < 0.02 for 24-h ambulatory SBP), left ventricular wall thickness (r = -0.34, P < 0.02) and serum fibrinogen level (r = -0.63, P < 0.0001). However, multiple regression analysis showed that insulin sensitivity was more closely related to diastolic filling than to blood pressure or left ventricular wall thickness. CONCLUSION: The present study showed left ventricular wall thickness to be closely associated with insulin resistance. Because diastolic dysfunction of the left ventricle was also related to a decreased insulin sensitivity, these findings suggest that left ventricular hypertrophy and diastolic dysfunction are associated with the insulin resistance metabolic syndrome.

On the use of ambulatory blood pressure recordings and insulin sensitivity measurements in support of the insulin-hypertension hypothesis.

OBJECTIVE: To determine the possible correlations between ambulatory blood pressure and insulin sensitivity, compared with correlations between office blood pressure and insulin. DESIGN: Observational study. SETTING: Policlinic at the Department of Geriatrics, Uppsala, Sweden. PATIENTS: Caucasian patients (n = 149) of both sexes with untreated essential hypertension. MAIN OUTCOME MEASURES: The hyperinsulinaemic euglycaemic clamp and office blood pressure in all subjects. In subgroups, also the oral glucose-tolerance test (n = 96) and 24-h ambulatory blood pressure (n = 84). RESULTS: Significant correlations were seen between the insulin sensitivity index and ambulatory blood pressure recordings, whereas fasting plasma insulin levels were uncorrelated with office blood pressure. The insulin sum and the 2-h insulin level of the oral glucose-tolerance test were more closely correlated with ambulatory blood pressure recordings than was the fasting insulin level. In multiple regression analyses the night-time diastolic blood pressure showed a significant correlation with the insulin sensitivity index even after controlling for the effects of sex, age and body mass index. CONCLUSION: The apparent association between blood pressure and insulin resistance not only is obscured by measurement error, but is also affected by the particular measures of insulin resistance and blood pressure used. The present study provides further evidence that a relationship exists between blood pressure and hyperinsulinaemia or insulin resistance.

Influences of different antihypertensive treatments on indices of systemic mineral metabolism.

A negative calcium balance has previously been described in human hypertension with low levels of plasma ionized calcium (Ca2+) and an increased urinary excretion of calcium. The cause of this disturbance in mineral metabolism is not known, nor is it known if this derangement could be abolished if blood pressure is reduced by antihypertensive treatment. In the present investigation, the effects of antihypertensive monotherapy on serum and fasting urinary electrolytes were studied. For 3 to 6 months, 319 hypertensive patients entered 17 study groups, each group using one of the following antihypertensive drugs: dilevalol, metoprolol, antenolol, pindolol, propranolol, hydrochlorothiazide, bendrofluomethiazide, furosemide, spironolactone, doxazocine, prazocine, diltiazem, verapamil, nifedipine, isradipine, captopril, or lisinopril. Treatment with different beta-blockers, as well as diuretics, reduced the fasting urinary calcium excretion (P < .001). However, while the beta-blockers increased the proportion of the ionized form of calcium in blood (Ca2+) (P < .001), Ca2+ was further decreased by diuretic treatment (P < .05). Angiotensin converting enzyme inhibitors caused no major changes in mineral metabolism while of the calcium antagonists studied only verapamil raised the levels of Ca2+ (P < .01). No significant relationship between the changes in mineral metabolism and the reduction in blood pressure was observed in any of the treatment groups. Of the antihypertensive drugs used in the present study, beta-blockers appeared to reverse the basic abnormality with regard to calcium balance, suggesting that the activity of the sympathetic nerve system is involved in the disturbed calcium metabolism seen in hypertensive patients.