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Biomedical subjects

B Henning

Publications and source records attributed to B Henning.

At least 19 recordsLinked to original sources

Nephrolithiasis and hematuria--sometimes a stony road to diagnosis.

We report a case of a young man with a history of kidney stones. Occurrence of gross hematuria several months after the extracorporeal shock wave, lithotripsy (ESWL) treatment lead to hospitalization. By ultrasound and abdominal CT scan, the urologist could exclude post-renal causes of the gross hematuria and acute renal failure. After transfer to a department of nephrology hemodialysis was started, an immediate kidney biopsy was performed and prednisolone was administered on the same day. The kidney biopsy revealed an anti-glomerular basement membrane (GBM) disease. The renal function did not recover and the patient remained on hemodialysis. In the literature it has been hypothesized that ESWL-treated patients are prone to develop anti-GBM disease by liberation of glomerular basement antigen through the ESWL high energy shock waves. An additional hypothesis considering the higher susceptibility for anti-GBM disease among certain HLA-tissue types is discussed with regard to our case. Unfortunately, the prolonged track to diagnosis and delayed immunosuppressive treatment could not prevent poor clinical outcome. Although anti-GBM disease is a rather rare disease, it should be included as a differential diagnosis for hematuria--especially months after ESWL treatment. Otherwise early diagnosis may be missed and as in our patient immunosuppressive treatment will remain unsuccessful to recover renal function.

Adult↗

Oral probiotics can resolve urogenital infections.

We report the first clinical evidence that probiotic lactobacilli can be delivered to the vagina following oral intake. In 10 women with a history of recurrent yeast vaginitis, bacterial vaginosis (BV) and urinary tract infections, strains Lactobacillus rhamnosus GR-1 and Lactobacillus fermentum RC-14 suspended in skim milk and given twice daily for 14 days, were recovered from the vagina and identified by morphology and molecular typing within 1 week of commencement of therapy. In six cases of asymptomatic BV or intermediate BV (based upon Nugent scoring) was resolved within 1 week of therapy.

Administration, Oral↗

Ultrasonic sensor properties characterized by a PC-controlled scanning measuring system

The use of ultrasonic sensors for process control is currently widespread for flow, level or distance measurements. Recently, interest has increased, too in the application of ultrasonic sensors to concentration measurements in complex liquids. In this application there are high demands for a defined and stable quality of the properties of both the sensor transfer function and the sound field characteristic. For a detailed investigation and characterization of ultrasonic sensor propertiess, an efficient PC-controlled measuring system was developed by the Institut fur Automation und Kommunikation (IFAK). In this contribution, this high performance approach is presented to make visible the vibrating ultrasonic sensor surface as well as the sound field in front of acoustic sensors in liquids.

Journal Article↗

In-line concentration measurement in complex liquids using ultrasonic sensors

Recently there has been increased demand for chemical sensors measuring in-line the concentration of selected substances in complex liquids in order to guarantee a high product quality in the process industry. At present there is a great interest in acoustic sensor systems for concentration measurements. This article presents a new ultrasonic sensor system consisting of a miniaturized multi-sensor arrangement for the comprehensive acoustic characterization of liquid mixtures. The sensor system measures sound velocity, impedance coefficient, attenuation coefficient and temperature.

Journal Article↗

Multiple myeloma involving the stomach with vitamin B12 deficiency.

Involvement of the gastrointestinal tract by plasmocytoma is rare. In a 78-year-old man with IgA lambda multiple myeloma stage IIIB, the evaluation of a megaloblastic anaemia revealed a subnormal vitamin B12 level. Urinary excretion of isotope-labelled vitamin B12 was reduced. Tests for gastric parietal cell and intrinsic factor antibodies were negative. There were no clinical signs of an insufficient absorption in the ileum. Biopsy specimens of the stomach showed a dense, diffuse infiltrate of malignant plasma cells in the lamina propria of fundus and corpus. A urease test for Helicobacter pylori was positive. There was a minor haematological improvement when vitamin B12 was given parenterally. Several combinations of cytostatic drugs had no effect on the manifestations of the multiple myeloma. In our patient the vitamin B12 deficiency may be related to a displacement or destruction of parietal cells by malignant plasma cells.

Aged↗

Effects of P2 purinoceptor agonists on membrane potential and intracellular Ca2+ of human cardiac endothelial cells.

Vasoactive agonists like adenosine-5'-triphosphate (ATP) increase intracellular Ca2+ ([Ca2+]i) in vascular endothelial cells with an initial peak due to inositol 1,4,5-triphosphate-mediated Ca2+ release from intracellular stores followed by a sustained plateau that is dependent on the presence of extracellular Ca2+, thus leading to an increased synthesis and release of prostacyclin and nitric oxide. We studied the effects of nucleotides on membrane potential and [Ca2+]i in confluent human microvascular cardiac endothelial cells obtained from patients with dilated cardiomyopathy. The whole-cell configuration of the patch-clamp technique and a confocal laser scanning microscope employing fluo-3 as a Ca2+ indicator were used. Both uridine-5'-triphosphate (UTP) and 2-methylthioadenosine-5'-triphosphate (2MeSATP) induced depolarizations in human microvascular cardiac endothelial cells and increased [Ca2+]i with a rank order of potency 2MeSATP>ATP=UTP (EC50 values (in microM) were 0.084 2MeSATP, 0.67 ATP and 1.1 UTP). This suggests that both P2u and P2y purinoceptors are present on human microvascular cardiac endothelial cells. Maximal [Ca2+]i responses of confluent human microvascular cardiac endothelial cell monolayers to UTP were lower when compared to 2MeSATP. Nucleotide-induced increases in [Ca2+]i consisted of a transient peak, which was also observed in the absence of extracellular Ca2+, and a sustained [Ca2+]i plateau. This plateau, which was not observed in all monolayers studied, was not markedly influenced by increasing extracellular [K+]. Previous incubation with thapsigargin abolished ATP-induced increases of [Ca2+]i. It is concluded that human microvascular cardiac endothelial cells express both P2y and P2u purinoceptors. P2 purinoceptor agonists release Ca2+ from intracellular thapsigargin-sensitive stores and stimulate capacitative Ca2+ influx pathways. K+ efflux through Ca2+-dependent K+ (K(Ca)) channels does not play a major role in the regulation of nucleotide-induced Ca2+ influx in human microvascular cardiac endothelial cells, which might be related to an impaired function of the cells.

Adenosine Triphosphate↗

[Intramural pseudodiverticulosis of the esophagus. Diagnosis on second look].

HISTORY: Case 1. A 56-year-old man had experienced increasing dysphagia for 6 months, accompanied by a weight loss of 20 kg. A stenosing oesophageal carcinoma was suspected. Case 2. A 82-year-old man had been suffering intermittently from nausea for some years but had maintained his weight (80 kg; height 173 cm). Endoscopy 4 months before this admission had revealed a duodenal ulcer; its treatment briefly improved the symptoms. INVESTIGATIONS, DIAGNOSIS AND TREATMENT: Endoscopy in case 1 detected a severe oesophageal stenosis which could not be passed, and its cause could not be ascertained despite biopsy, barium swallow and computed tomography. After bougie dilatation an endoscope was finally passed and the typical picture of oesophageal pseudodiverticulosis (OPD) seen. In case 2, endoscopy at first indicated only marked Candida oesophagitis. But after antimycotic treatment a second endoscopy revealed OPD. No treatment is known nor necessary since OPD causes no clinical symptoms unless there are complications. CONCLUSIONS: OPD, a rare condition, presents in various ways, both in its symptoms and at endoscopy. In case of oesophageal stenosis of unknown cause or Candida oesophagitis repeat endoscopy my be necessary to establish the true diagnosis: OPD should be included in the differential diagnosis.

Aged↗

[Villous bile duct adenoma with mucinous bile ].

HISTORY AND ADMISSION FINDINGS: A 75-year-old woman was admitted because of colicky upper abdominal pain. Physical examination was unremarkable. INVESTIGATIONS: Alkaline phosphatase and gamma-glutamyl transpeptidase activities as well erythrocyte sedimentation rate were increased. Sonography revealed mild enlargement of the hepatocholedochal duct to 1.1 cm. Retrograde endoscopy showed a band-like immobile structure in the cystic duct. TREATMENT AND COURSE: At operation the hepatocholedochal duct was found to contain a greenish mucinous mass: no cause was discovered. Three years later a tumor, 1 x 0.5 cm, was found in the common hepatic duct at sonography, with clinical signs of recurrent chronic cholitis and early liver damage. Because of hepatic dysfunction and hypersplenism no surgical intervention was undertaken. When cholestasis progressed further, a partial full-thickness resection of the hepatic duct with removal of the tumor and the mucinous bile had to be performed two years later. Histological examination revealed a villous adenoma with slight epithelial dysplasia and mucus formation. CONCLUSIONS: Villous bile duct adenoma is a very rare cause of cholestasis. Mucous production can lead to mucinous bile, with resulting chronic cholecystitis and secondary biliary cirrhosis. The adenoma should be completely excised because of the danger of malignant transformation and risk of local recurrence.

Adenoma, Villous↗

Effects of tolbutamide on ATP-sensitive K+ channels from human right atrial cardiac myocytes.

In order to gain further insight into possible deleterious effects on ischaemia-induced myocardial damage induced by sulfonylureas when administered to humans, the effects of tolbutamide on ATP-sensitive K+ (KATP) channels from human right atrial myocytes were studied. Single myocytes were enzymatically isolated from human right atrium. The cell-attached and inside-out configuration of the patch-clamp technique were employed at room temperature (both the pipette and the bath solution contained high [K+]). KATP channels in inside-out patches showed slight inward rectification, had a slope conductance of 75.1 +/- 2.4 pS (mean +/- S.E.M.; n = 5) at negative membrane potentials and these channels were blocked by ATP (half-maximal block (EC50) at 39 microM; Hill coefficient = 1.65). In cell-attached recordings, cromakalim (300 microM) opened KATP channels (with a slope conductance of 73.3 +/- 1.8 pS (n = 16) at negative membrane potentials) in previously silent patches. Cromakalim-induced openings of KATP channels were not markedly affected by 100 or 300 microM tolbutamide but were blocked by tolbutamide at millimolar concentrations (1-3 mM). The concentration-response relationship for tolbutamide-induced block of KATP channels in the presence of 300 microM cromakalim in cell-attached patches was calculated to values for the EC50 of 1.325 mM and for the Hill coefficient of 1.0, respectively. 1 mM tolbutamide-induced block of cromakalim-induced KATP channel openings was not different at room temperature when compared to 37 degrees. It is concluded that KATP channels from human right atrial myocytes have a low sensitivity towards tolbutamide-induced block.

Adenosine Triphosphate↗

The epidemiology of diabetes in pregnant Native Canadians. A risk profile.

OBJECTIVE: The purpose of this study was to determine the prevalence of diabetes in pregnancy (gestational diabetes mellitus [GDM] and NIDDM) and to identify risk factors in the development of GDM in a native population in northwestern Ontario, Canada. RESEARCH DESIGN AND METHODS: A retrospective analysis of 1,305 singleton deliveries among Ojibwa-Cree women from northwestern Ontario, Canada, was conducted from 1990 to 1993 inclusive. GDM was diagnosed using a 3-h oral glucose tolerance test (OGTT) and defined according to standard guidelines. RESULTS: The overall prevalence of diabetes in pregnancy (NIDDM and GDM) was 11.6% (152 of 1,305) with a GDM prevalence of 8.4% (110 of 1,305). Among 741 women with complete data, prevalence rates increased with age, peaking at 46.9% in the age-group > or = 35 years. Significant risk factors for GDM included older maternal age, multiparity, prepregnancy obesity, a family history of diabetes, and a history of GDM in previous pregnancies. CONCLUSIONS: Diabetes in pregnancy among Ojibwa-Cree reported here represent the highest rates reported to date in a Canadian population. The high rates of maternal obesity and relative young age of this population further highlight the urgent need for diabetes screening and prevention in this population.

Adolescent↗

Ciguatera fish poisoning following travel to the tropics.

A 40-year-old man-as well as 15 more participants of the same meal-suddenly experienced vomiting and watery diarrhea four hours after having eaten a meal of grouper in the Dominican Republic. Symptoms persisted for four hours and were followed by a generalized pruritus and paresthesias of the lips, tongue, palms, and soles of the feet. Physical examination was normal with the exception of a pulse of 45 beats per minute, a blood pressure of 80/50 mmHg, and paradoxical temperature perception. Laboratory values were regular except for the erythrocyte sedimentation rate of 40 mm per hour. 24-hour Holter electrocardiogram showed a normal sinus rhythm with impaired heart rate variability (37-100 beats per minute). Due to the typical history and the clinical findings, ciguatera toxin ingestion was diagnosed. Pruritus decreased slightly with symptomatic therapy, but it took 16 weeks for all symptoms to resolve. Ciguatera fish poisoning is rare in temperate countries. Symptoms of this neurotoxic disease are gastrointestinal, neurologic, and cardiovascular manifestations with paresthesias, paradoxical sensor disturbances, and muscular weakness as well as bradycardia and hypotension. With travel to and from the tropics and increasing imports of tropical fish ciguatera will be of growing importance even in nontropical areas.

Adult↗

Chamber for indirect calorimetry with improved transient response.

A chamber for indirect calorimetry has been constructed that utilises previously published general equations for the calculation of respiration. Owing to the large size of the chamber, the changes in gas concentration caused by a subject are very small. Therefore, algorithms are developed for noise suppression and trend identification. Using the exact solution of the equations for steady state, each gas concentration is fitted by a least square method to two connected exponential segments, of variable length, for the preceding 30 min period. Independently of the location of the join between the two segments, the gas concentration and its time derivative are evaluated at -15 min. This process is repeated, and its results are presented once every minute. As proven by gas injection tests, this procedure gives an instantaneous response to a single change in respiration, a correct averaging of repeated changes in respiration with periods of less than 15 min and noise suppression. It is concluded that this chamber is useful not only for traditional 24 h energy expenditure measurements, but also for experiments requiring rapid responses.

Algorithms↗

Lack of therapeutic efficacy of vitamin A for non-cholera, watery diarrhoea in Bangladeshi children.

Vitamin A deficiency has been postulated to increase childhood mortality, possibly through increasing the severity and case-fatality of infectious diseases like diarrhoea. A clinical trial was conducted to measure the effect of vitamin A therapy on the severity and duration of acute episodes of non-cholera, watery diarrhoea; 83 children with less than 48 h of illness were randomized to receive vitamin A (200,000 IU of retinyl palmitate) orally or placebo during hospitalization at the International Centre for Diarrhoeal Disease Research in Bangladesh. The patients were similar initially with regard to age, nutritional status and severity of diarrhoea prior to admission. No adverse effects of vitamin A were detected. During hospitalization there were no differences between groups in duration of illness or stool output. Thus, vitamin A can be given safely during diarrhoeal illness to augment hepatic reserves and possibly provide a beneficial effect in regard to subsequent episodes of diarrhoea and other infections, but this supplementation should not be expected to have a therapeutic effect on a current episode.

Bangladesh↗

The effect of heart rate on the arrhythmogenic transient inward current in isolated sheep cardiac Purkinje fibres.

1. The effect of heart rate on the arrhythmogenic transient inward current (ITI) has been studied in sheep cardiac Purkinje fibres. 2. Transient inward current and force (active force, tonic force and the after-contraction) have been measured in voltage-clamped preparations. Intracellular Na+ activity (aiNa) was measured simultaneously using Na(+)-sensitive microelectrodes. The effects of changes in voltage-clamp pulse frequency on the ITI amplitude, active force, tonic force, the after-contraction and aiNa have been investigated in different bathing solutions. 3. After a stepwise increase in pulse rate there was a biphasic response of ITI amplitude: a short-lasting (50 s) phase during which ITI amplitude increased followed by a decline in ITI amplitude. The second phase could be fitted by an exponential with a time constant between 102 and 184 s. The after-contraction changed in a similar biphasic manner whereas force and aiNa declined monophasically; active force first declined, increased and then declined again. These changes were greater at faster rates of pulsing. 4. Linear relationships between ITI amplitude, after-contraction amplitude and tonic force were observed in all experiments. 5. In K(+)-free solution the response of the ITI was markedly changed. After an increase in pulse rate the initial increase in ITI was enhanced, whereas the subsequent decline was strongly reduced or even abolished. Potassium-free solution blocks the Na+ pump, and activation of the Na+ pump by addition of Cs+ or K+ restored the phase of decay of ITI amplitude during rapid stimulation. 6. A reduction of external Na+ to about 50% or elevation of external Ca2+ increased ITI but had little effect on the rate-dependent changes in the current. 7. When stimulation was resumed at the basic pulse rate after a period of rapid pulsing the ITI amplitude initially continued to decline: this was followed by a slow recovery (over 10-15 min) of ITI amplitude back to its steady-state value prior to fast pulsing. 8. These results are consistent with the hypothesis that changes of ITI are the result of rate-dependent changes in intracellular Ca2+, which in turn are in part dependent on changes of intracellular Na+.

Action Potentials↗

[Bepridil--electrophysiologic properties of a new calcium antagonist with an anti-arrhythmia effect].

In 12 patients with recurrent pre-syncope or syncope and suspected sick sinus syndrome, the electrophysiologic properties of bepridil were tested using 1-2 extrastimuli during four basic pacing rates. Bepridil was given in a dose of 5 mg/kg body weight over 10 min. It caused no significant changes in sinus cycle length (+5%) and corrected sinus node recovery time during pacing of 100/min (-6%), 120/min (+8%) and 140/min (+4%). The conduction times PQ- (+10%) and QRS-interval (+6%) increased significantly, AH- (+8%) and HV-interval (+5%) were slightly prolonged. Antegrade Wenckebach point increased from 460 to 508 ms (p less than 0.05). The effective refractory period was prolonged in the atrium (+11%, p less than 0.05), the AV-node (+14%, p less than 0.05) and the right ventricle (6-11% at pacing rates 100-140/min, p less than 0.05 for each cycle length). In relation to the pacing rate, QTc-interval increased highly significantly (p less than 0.01) by 16% (sinus rhythm), 12% (100/min), 20% (120/min) and 19% (140/min). After a mean of 5 min after the start of infusion a doubled T-wave was observed in 11/12 patients, persisting during Holter monitoring for several hours without evidence of increased incidence of spontaneous ventricular arrhythmias. During programmed electrical stimulation with 1-2 extrastimuli, no increase in vulnerability of the right ventricle was obvious in any patient.

Adolescent↗

Triggered activity in atrial fibres of canine coronary sinus: role of extracellular potassium accumulation and depletion.

1. Bursts of triggered activity can be induced in atrial fibres of the canine coronary sinus exposed to catecholamines. During a triggered burst there is an initial acceleration of rate accompanied by depolarization of the maximum diastolic potential (m.d.p.) followed by slowing of the rate and termination accompanied by hyperpolarization. 2. We have used extracellular K+-sensitive micro-electrodes (potassium ISE) to monitor extracellular K+ concentration ([K+]o) during and following triggered activity, while simultaneously measuring membrane potential with conventional intracellular micro-electrodes. 3. We found that the initial increase in rate during triggered activity is accompanied by increased [K+]o and depolarization. Later rate slowing and m.d.p. hyperpolarization is accompanied by decline of extracellular K+ accumulation. Following termination of triggered activity, extracellular K+ depletion occurred. 4. The decline of [K+]o and slowing of rate are known responses to enhanced Na+-K+ pump activation, as is the post-triggering depletion of extracellular K+. 5. Strophanthidin, which blocks the Na+-K+ pump, also blocks the [K+]o decline, the slowing of rate seen towards the end of the triggered episode, and the post-triggering depletion of extracellular K+. 6. Separate experiments studying the effects of elevated bath K+ and depolarizing current on triggering rate and delayed after-depolarization amplitude support our hypothesis that the rate profile of the triggered episode is to a large extent controlled by variations in m.d.p. subsequent to extracellular K+ accumulation and Na+-K+ pump activation.

Action Potentials↗

In vitro regulation of 3-hydroxy-3-methylglutarylcoenzyme A reductase and acylcoenzyme A: cholesterol acyltransferase activities by phosphorylation-dephosphorylation in rabbit intestine.

The regulation of 3-hydroxy-3-methylglutarylcoenzyme A reductase and acylcoenzyme A:cholesterol acyltransferase activities by phosphorylation-dephosphorylation in rabbit intestine was studied in vitro. Preparing intestinal microsomes in the presence of 50 mM NaF caused a 64% decrease in the reductase activity. It had no effect on acyl-CoA:cholesterol acyltransferase activity. Microsomes that were prepared in NaF were incubated with intestinal cytosol, a partially purified phosphatase from cytosol, and Escherichia coli alkaline phosphatase. All three preparations increased 3-hydroxy-3-methylglutaryl-CoA reductase by two- or three-fold suggesting dephosphorylation and 'reactivation' of enzyme activity. Cytosol caused a 78% increase in acyl-CoA:cholesterol acyltransferase activity, but neither the partially purified phosphatase nor the E. coli alkaline phosphatase affected the acyltransferase activity. Microsomes incubated with increasing concentrations of MgCl2 and ATP decreased both the activities of 3-hydroxy-3-methylglutaryl-CoA reductase and acylcoenzyme A:cholesterol acyltransferase in a step-wise fashion. Whereas this inhibitory effect was specific for reductase, the effect on acyl-CoA:cholesterol acyltransferase activity was secondary to the presence of ATP in the assay mixture. The 8500 X g supernatant of intestinal whole homogenate from isolated intestinal cells or scraped mucosa was incubated with MgCl2, ATP and NaF. In microsomes prepared from this supernatant, the activity of 3-hydroxy-3-methylglutaryl-CoA reductase was significantly decreased. Again, no change was observed in the acyltransferase activity. The rate of cholesterol esterification in isolated intestinal cells was not affected by 0.1 mM cAMP or 50 mM NaF. We conclude that under conditions which regulate 3-hydroxy-3-methylglutaryl-CoA reductase activity in rabbit intestine by phosphorylation-dephosphorylation, no regulation of acyl-CoA:cholesterol acyltransferase activity is observed.

Adenosine Triphosphate↗

The time course of action potential repolarization affects delayed afterdepolarization amplitude in atrial fibers of the canine coronary sinus.

The effects of changing the time course of action potential repolarization on the amplitude and coupling interval of delayed afterdepolarizations were studied in small preparations of coronary sinus atrial fibers exposed to catecholamines. Repolarization was accelerated or retarded by current pulses passed through an intracellular microelectrode in the depolarizing or repolarizing direction. Acceleration of repolarization decreased the amplitude of delayed afterdepolarizations, prolonged their coupling interval to the action potential upstroke, and prevented triggered activity. Prolonging the time for repolarization increased afterdepolarization amplitude, shortened the coupling interval, and caused triggered activity. The afterdepolarization amplitude and coupling interval had a linear relationship to the duration of the action potential plateau. In some preparations, the action potential plateau increased spontaneously at stimulation rates that caused afterdepolarization amplitude to increase and triggering to occur, and this may have contributed to the occurrence of triggering. The effects of action potential repolarization on delayed afterdepolarizations suggest that pharmacological agents such as antiarrhythmic drugs which alter action potential duration should influence afterdepolarizations. Drugs which shorten action potential duration might prevent triggered activity from occurring, whereas drugs which prolong duration might cause triggering.

Action Potentials↗