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Biomedical subjects

T Jensen

Publications and source records attributed to T Jensen.

At least 91 records · Page 5Linked to original sources
PubMed1995

Vascular endothelial cell function and cardiovascular risk factors in patients with chronic renal failure.

Cardiovascular risk factors and markers of endothelial cell function were studied in nondiabetic patients with mild to moderate chronic renal failure. The transcapillary escape rate of albumin and the plasma concentrations of von Willebrand factor, fibrinogen, and plasma lipids were measured in 29 nondiabetic patients (GFR of 25 (11-44) mL/min x 1.73 m2 (median and range)) and 14 normal subjects. The proportion of smokers was similar between the groups. In the patients, the plasma concentration of von Willebrand factor was elevated by 61% (1.27 +/- 0.44 versus 0.79 +/- 0.28 U/mL; P < 0.01) (mean +/- SD) and that of fibrinogen was elevated by 72% (10.18 +/- 4.14 versus 5.92 +/- 2.01 mumol/L; P < 0.01). The plasma concentrations of lipoproteins showed an atherogenic pattern in the patients with increased levels of very low-density lipoprotein cholesterol (0.57 +/- 0.31 versus 0.33 +/- 0.13 mmol/L; P < 0.01) and triglycerides (1.26 +/- 0.25 versus 0.71 +/- 0.28 mmol/L; P < 0.01), but a decreased level of high-density lipoprotein cholesterol (1.23 +/- 0.33 versus 1.46 +/- 0.35 mmol/L; P < 0.05). Total cholesterol and low-density lipoprotein cholesterol were similar in the groups. The observed differences were further aggravated among smoking patients, particularly with respect to von Willebrand factor and triglycerides. The transcapillary escape rate of albumin was similar in the patients and the controls and was not correlated to the level of albuminuria.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Anopheles perplexens from artificial containers and intermittently flooded swamps in northern Florida.

Anopheles perplexens was collected from habitats previously unreported for this species in northern Florida. These habitats included intermittently flooded swamps, water-filled tires, and plastic oviposition cups. First-instar An. perplexens larvae were recovered from soil samples collected in an intermittently flooded swamp that were flooded in the laboratory, suggesting that An. perplexens eggs may survive in the soil during dry periods. Anopheles perplexens larvae were collected from water-filled tires and plastic oviposition cups at sites near Gainesville, FL. Of 30 dissected An. perplexens females collected in updraft CDC traps, all had ovarioles in Christophers's stage II and blood was absent in the midgut. The physiological state of these females indicates that updraft CDC traps collect predominately host-seeking females and that females take one blood meal per gonotrophic cycle.

Animals↗
PubMed1995

Natural killer cells in peripheral blood after autologous bone marrow transplantation: a combined phenotypic and functional study.

The peripheral blood regeneration of natural killer (NK) cells was studied before and on 5 occasions during the first 6 weeks after autologous bone marrow transplantation (auto-BMT) in 10 patients with hematological malignancies and solid tumors. The number of NK cells (relative as well as absolute), enumerated by their lack of CD3 and their expression of CD56 recovered after a severe decline 1 week posttransplant to increase beyond pretransplantation levels during the next 2 weeks. Similar patterns were seen for the average NK activity against K562 as well as LAK cell lytic activity against Daudi but without the overshoot at weeks 2-3. Moreover, the fraction, but not the absolute numbers, of NK cells was found to correlate to the lytic NK activity. In contrast, no phenotypic marker was correlated to LAK activity. Immunophenotypic studies using three-color flow cytometry revealed that during the first 2 weeks after auto-BMT the phenotype of NK cells changed towards an immature phenotype (decreased CD45RA and CD11a) 1 week after transplant to an activated (increase in CD25, HLA-DR and CD11c) after 2-4 weeks. However, when the absolute number of selected phenotypically defined NK cell subsets(CD45RA, CD45RB, CD11a, CD11c, CD2, CD25, HLA-DR and fibronectin expressing CD56+,CD3- NK cells) were compared to the cytotoxic activity for each patient, we were not able to show any correlations except between the activation-related antigens CD25 and HLA-DR on the one hand, and NK lysis on the other, and only 3 weeks after auto-BMT. We conclude that NK cell function recovers quickly following auto-BMT concomitantly with the emergence of a transiently altered phenotype which increased expression of activation-related antigens.

Adult↗
PubMed1994

[Multiple liver abscesses caused by Fusobacterium necrophorum infection].

A case of multiple liver abscesses caused by Fusobacterium necrophorum infection is presented. In cases with fever of unknown origin and biochemical signs of derangement of hepatic function, it is recommended that an abdominal scan is performed. Before initiating antibiotic treatment relevant specimens should be collected. Finally we describe how the use of resin-containing blood culture medium enhance the possibility of bacterial detection in patients receiving antibiotics.

Diagnosis, Differential↗
PubMed1994

[Cryptococcal meningitis in patients without predisposing immunodeficiency].

Cryptococcal meningitis is a chronic or subacute meningeal infection that may have pulmonary or systemic manifestations and is caused by the yeast Cryptococcus neoformans. It has become an increasingly important pathogen in immunocompromised hosts, whereas cryptococcal meningitis is relatively rare in immunocompetent patients. The diagnosis is often delayed because of the sparse and nonspecific symptoms. We present two cases of cryptococcal meningitis in two patients without known predisposing factors. The symptomatology, diagnosis and treatment of the disease are discussed. The two cases illustrate that Cryptococcus neoformans should be considered in patients with cerebral symptoms and fever. The disease is potentially curable and early diagnosis with specific treatment are important prognostic factors.

Aged↗
PubMed1994

Control of non-insulin-dependent diabetes mellitus partially normalizes the increase in hepatic efficacy for urea synthesis.

The relation of urea synthesis rate to blood alanine concentration was assessed in seven healthy controls and eight patients with non-insulin-dependent diabetes mellitus (NIDDM) before (hemoglobin A1c [HbA1c] = 9.9% +/- 1.9%, mean +/- SD) and after (HbA1c = 7.9% +/- 0.8%) improvement of metabolic control. Following an overnight fast, alanine was infused at a rate of 2 mmol/(h.kg body weight [BW]). The hourly rate of urea synthesis was determined as the urinary excretion of urea corrected for accumulation of urea in total body water (TBW) and intestinal hydrolysis. The functional hepatic nitrogen clearance (FHNC) was calculated as the slope of the linear relation of urea synthesis rate to blood alanine concentration. The glucagon level was increased by twofold at the first investigation, but was not increased at the second. The insulin level was moderately increased at both investigations. In controls FHNC was 21.8 +/- 4.4 L/h, in poorly controlled patients it was increased to 36.6 +/- 4.3 L/h (P < .01), and following improvement of metabolic control it was not different from control levels at 28.6 +/- 4.3 L/h. By correlation analyses, FHNC was found only to be related to the fasting glucose value, albeit weakly (R2 = .39). In conclusion, hepatic kinetics of urea synthesis in poorly controlled NIDDM patients are changed in favor of increased conversion of alanine N to urea N at any amino acid concentration. This perturbation is partially normalized by improved metabolic control.

Adult↗
PubMed1994

Comparison of recapture patterns of marked and released Aedes vexans and Ae. melanimon (Diptera: Culicidae) in the Sacramento Valley of California.

Recapture patterns of Aedes vexans (Meigen) and Aedes melanimon Dyar were compared in a mark-release-recapture study conducted on the Colusa National Wildlife Refuge, Colusa County, California, from 15 August to 2 September 1988. The 2.0% recapture rate for Ae. vexans females was significantly greater than the 0.9% rate for Ae. melanimon females. Daily survivorship of 0.70 for Ae. vexans females was significantly lower than the 0.84 estimate for Ae. melanimon. The two species had different patterns of dispersal. On day 1, when the majority of marked females of both species were recaptured, the mean dispersal distance for Ae. vexans females was significantly greater than that for Ae. melanimon. The cumulative dispersal distance for Ae. vexans females decreased over the study period. In contrast, Ae. melanimon dispersal distances increased gradually over time.

Aedes↗
PubMed1994

Comparison of bi-directional Fay, omni-directional, CDC, and duplex cone traps for sampling adult Aedes albopictus and Aedes aegypti in north Florida.

We compared the number of Aedes albopictus and Aedes aegypti females collected in CDC, duplex cone, bi-directional Fay, and new omni-directional traps in a series of trials in northern Florida during 1992 and 1993. Bi-directional Fay and omni-directional traps collected significantly more Ae. albopictus females than did the other traps tested. The bi-directional Fay trap collected significantly more Ae. aegypti females than did any other trap. The results of these studies indicate that these traps may be useful tools for sampling Ae. albopictus and Ae. aegypti adults.

Aedes↗
PubMed1993

Transcapillary escape rate of albumin in hypertensive patients with type 1 (insulin-dependent) diabetes mellitus.

Diabetic patients with elevated urinary albumin excretion rate (incipient or clinical nephropathy) also have an increased transcapillary escape rate of albumin. This study was designed to clarify whether this is caused by a general vascular dysfunction or by elevated systemic blood pressure. The systemic blood pressure and the transcapillary escape rate of albumin were measured in the following groups after 4 weeks without antihypertensive treatment: Group 1--eleven healthy control subjects. Group 2--ten Type 1 (insulin-dependent) diabetic patients with incipient nephropathy (urinary albumin excretion rate: 30-300 mg/24 h) and normal blood pressure. Group 3--eleven non-diabetic patients with essential hypertension. Group 4--nine Type 1 diabetic patients with hypertension but normal urinary albumin excretion (< 30 mg/24 h). Group 5--eleven Type 1 diabetic patients with nephropathy (urinary albumin excretion rate > 300 mg/24 h) and hypertension. Systolic and diastolic blood pressure were similar in the three hypertensive groups: group 3, 148 +/- 8/95 +/- 6; group 4, 150 +/- 12/94 +/- 8 and group 5; 152 +/- 12/92 +/- 7 mmHg, but significantly elevated (p < 0.001) compared to control group 1, 117 +/- 12/74 +/- 9 and group 2, 128 +/- 7/82 +/- 4 mmHg. The transcapillary escape rate of albumin was similar in the control subjects (5.2 +/- 2.7%) and the subjects in the normoalbuminuric groups 3 and 4 (6.2 +/- 1.9 and 5.1 +/- 1.4%, respectively) and significantly lower (p < 0.001) than in patients with elevated urinary albumin excretion without or with hypertension group 2, 10.1 +/- 2.8 and group 5, 11.4 +/- 5.7%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

The cystic fibrosis mutation (delta F508) does not influence the chloride channel activity of CFTR.

The cystic fibrosis transmembrane conductance regulator (CFTR) is a phosphorylation-regulated Cl- channel. In most mammalian cells, the functional consequences of the most common CF mutation, delta F508-CFTR, cannot be assessed as the mutant protein undergoes biosynthetic arrest. However, function can be studied in the baculovirus-insect cell expression system where delta F508-CFTR does not appear to undergo such arrest. Our results show that phosphorylation-regulated Cl- channel activity of delta F508-CFTR is similar to that of wild-type CFTR. This observation was confirmed in comparative studies of purified delta F508-CFTR and CFTR reconstituted in planar lipid bilayers. Therefore, we suggest that this common mutation does not result in a significant alteration in CFTR function.

Amino Acid Sequence↗
PubMed1993

Nature of elevated blood pressure in normoalbuminuric type I diabetic patients. Essential hypertension?

This study was undertaken to characterize type I diabetic patients with essential hypertension with respect to kidney function, renal hormones, and endothelial function. After 4 weeks without antihypertensive treatment, a cross-sectional study was carried out in the following groups: group 1, 14 healthy controls; group 2, 13 nondiabetic patients with essential hypertension (blood pressure > or = 140/90 mm Hg); group 3, 11 type I diabetic patients with hypertension but urinary albumin excretion (UAE) persistently normal (UAE: 10 mg/24 h, range 3 to 18) both before, during, and after discontinuing antihypertensive treatment; group 4, 15 type I diabetic patients with clinical nephropathy (UAE: 611 mg/24 h, range 192 to 3837) and hypertension. Systolic and diastolic blood pressures were similar in the three hypertensive groups: 147/96 +/- 8/6, 150/94 +/- 11/9, and 152/92 +/- 12/6 mm Hg (groups 2, 3, and 4, respectively) but elevated compared with controls (114/74 +/- 9/9 mm Hg, P < .001). The diabetic patients with essential hypertension were hyperfiltering in contrast to patients with nephropathy (glomerular filtration rate 114 +/- 23 v 90 +/- 21 mL/min/173 m2, P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Short-term population dynamics of adult Aedes dorsalis (Diptera: Culicidae) in a northern California tidal marsh.

Short-term changes in the age structure and abundance of the host-seeking population of Aedes dorsalis (Meigen) females were studied in a Northern California tidal marsh by daily sampling from 25 July through 17 August 1990. The calculated numbers of nulliparous and parous females per day were used to estimate parity rates and duration of the gonotrophic cycle. The numbers of females collected per day ranged from 261 to 74,443, and daily parity rates ranged from 0 to 91%. The overall parity rate was 14%. Two peaks in nulliparous female abundance on days 7 and 12 were followed 5 d later by increases in the number of parous females, indicating that two cohorts had emerged with gonotrophic cycle lengths of approximately 5 d. This is consistent with the 5-d gonotrophic cycle length estimated using time series analysis of the same data sets. Peak host-seeking activity of nulliparous females in the two cohorts occurred 16 d after two marsh systems were flooded by monthly high tides. Survivorship was estimated to be 14% per gonotrophic cycle and 67% per day, although emigration may have caused the substantial underestimation of actual survivorship.

Aedes↗
PubMed1993

Short-term changes in the abundance and parity rate of Anopheles quadrimaculatus species C (Diptera: Culicidae) in a central Florida swamp.

Updraft CDC traps baited with dry ice were used to monitor changes in the abundance and parity rate of Anopheles quadrimaculatus Say complex mosquitoes in an intermittently flooded swamp in Central Florida during an 18-d period. Mosquitoes collected each day were identified to species using DNA hybridization and isozyme electrophoretic techniques and were dissected to determine follicular maturation and parity. Of 1,178 An. quadrimaculatus mosquitoes identified to species, 4% were species A and 96% were species C. Dissections of females of both species indicated that 98% were nonblood fed and nongravid with ovariole development at Christophers' stage II. Overall parity rates were 0.19 and 0.51 for populations of species A and species C, respectively. The duration of the gonotrophic cycle for species C females was estimated to be 5 d based on the interval between peaks in the number of nulliparous females collected on days 1 and 6 and peaks in the number of parous females collected 5 d later. Significant trends were observed in the number of parous species C females collected each day, indicating that the parity rate could not be used as an unbiased estimator of survivorship.

Animals↗
PubMed1993

Fluoroquinolones in the treatment of cystic fibrosis.

Cystic fibrosis patients suffer from recurrent and chronic lung infections mainly caused by Staphylococcus aureus, Haemophilus influenzae and Pseudomonas aeruginosa. The fluoroquinolones, notably ciprofloxacin and ofloxacin, represent an important addition to the therapy of P. aeruginosa infections. They offer the possibility of effective oral treatment for early colonisation as well as chronic infections, even in children. They are associated with only few and mild adverse effects. Development of resistance represents an increasing problem.

Ciprofloxacin↗
PubMed1993

Morphine and morphine/naloxone modification of glucose, glucagon and insulin levels in fasted and fed rats.

In rats weighing 200-250 g catheters were placed in the internal jugular vein and carotid artery. After 1 week of accommodation the training for the experimental situation, morphine (10 mg kg-1) was injected intravenously alone or in combination with naloxone (0.04 mg ml-1, 0.8 ml h-1). Otherwise no form of anaesthesia was used during the experiments. In control fed and fasted rats, there were no significant differences in blood glucose. In fed rats, morphine increased blood glucose as compared to control rats (p < 0.001). This was not seen in the fasted rats. The morphine induced increase in blood glucose in the fed rats was abolished by naloxone (p < 0.001). Glucagon was significantly higher in fasted than in fed control rats (p < 0.01). It was significantly increased after morphine in fed (p < 0.05), but not in fasted rats. The morphine induced increase in glucagon in fed rats was abolished by naloxone (p < 0.01). Insulin was significantly higher in fed than in fasted control rats (p < 0.05). Morphine increased insulin levels significantly in fed and fasted rats (p < 0.001), p < 0.01). The morphine induced increase in insulin in the fed rats was abolished by naloxone treatment. It is concluded that morphine stimulates glucose and glucagon release in fed but not fasted rats, and that these increases are caused by opioid action. Insulin increases after morphine were proved to be opioid-mediated only in the fed state.

Animals↗
PubMed1993

Increased urinary loss of high density lipoproteins in albuminuric insulin-dependent diabetic patients.

The pathophysiological mechanisms resulting in hyperlipidaemia in albuminuric insulin-dependent diabetic patients are largely unknown. Increased non-specific hepatic protein synthesis as a response to urinary protein loss, has been proposed. However in that case it is unexplained why the plasma concentration of the high density lipoprotein (HDL) subfraction, in contrast to all other lipoprotein subfractions, is normal or even reduced in albuminuric patients. We studied the urinary excretion of HDL-cholesterol in 26 insulin-dependent diabetic patients matched according to sex and age into three groups. I: normal urinary albumin excretion (< 30 mg 24 h-1; n = 8); II: incipient nephropathy (urinary albumin excretion in the range of 30-300 mg 24 h-1; n = 7); and III: clinical nephropathy (urinary albumin excretion > 300 mg 24 h-1; n = 11). Eight normal subjects served as controls. Lipoproteins in urine were separated by ultracentrifugation, and the daily urinary loss of HDL-cholesterol was 1.30 mumol (0.83-2.21) (median and range) in controls, 1.27 mumol (0.56-2.59) in group I, 1.39 mumol (0.55-1.97) in group II and 4.02 mumol (1.33-42.12) in group III (p < 0.01). More than 95% of cholesterol in urine was found in the HDL-fraction. The plasma concentrations of total cholesterol, very low density lipoprotein cholesterol, low density lipoprotein cholesterol and triglyceride were 21-94% higher in patients with clinical nephropathy compared with normal controls and group I.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

A comparison of spirapril and isradipine in patients with diabetic nephropathy and hypertension.

The effects of spirapril and isradipine on blood pressure, urinary albumin excretion and sodium-volume homeostasis in hypertensive insulin-dependent diabetic patients with nephropathy were assessed. Fifteen Type 1 diabetic patients aged 28-53 years with a diabetes duration of 19-37 years were studied. All had hypertension and diabetic nephropathy with a urinary albumin excretion of more than 300 mg/24 h. After a single blind placebo treatment period of 4 weeks the patients were randomly assigned to treatment with the calcium antagonist isradipine SRO 5 mg once daily or the ACE inhibitor spirapril 6 mg once daily for 6 months in a double-blind design. Isradipine lowered ambulatory systolic blood pressure from 152 +/- 12 to 141 +/- 11 mmHg (p < 0.05) and ambulatory diastolic pressure from 91 +/- 9 to 86 +/- 8 mmHg (p < 0.05). The blood pressure lowering effect of spirapril was similar: 156 +/- 13 vs 143 +/- 11 mmHg (p < 0.01) and 90 +/- 4 vs 84 +/- 4 mmHg (p < 0.05). The fractional albumin clearance was unchanged on isradipine but decreased after 6 months treatment with spirapril with on average 20% (p < 0.05). Total body exchangeable sodium decreased on spirapril treatment: 2994 +/- 296 vs 2636 +/- 194 meq/1.73 m2 (p < 0.05) and extracellular volume tended to do so (p = 0.12). On isradipine treatment these parameters remained unchanged. In conclusion both isradipine and spirapril lowered blood pressure in patients with diabetic nephropathy. Only the ACE inhibitor had demonstrable beneficial effects on urinary albumin excretion rate and the sodium-volume expansion seen in these patients.

Adult↗