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Biomedical subjects

D Jensen

Publications and source records attributed to D Jensen.

At least 19 recordsLinked to original sources
PubMed1992

Less intensive long-term transfusion therapy for sickle cell anemia and cerebrovascular accident.

To determine the efficacy of a less intensive transfusion regimen in preventing recurrent cerebrovascular accidents and reducing transfusion requirements in patients with sickle cell anemia, we offered to 14 patients who had been undergoing aggressive transfusion therapy (sickle hemoglobin concentration kept less than 30% of total) for a mean of 9 years the option of either diminishing or stopping transfusion therapy. Thirteen patients chose to continue a modified transfusion regimen to maintain sickle hemoglobin concentration less than 60%; 10 of these patients have now been followed for 1 year or more (12 to 27 months, mean 15.5 months). There have been no recurrent neurologic events, although two patients have died of complications of hemochromatosis. All patients had a reduction in donor exposure, and there was a mean reduction in net transfusion requirement of 31.4% during the first year after modification. The greatest reduction was achieved in the single patient managed by small-volume (5 ml/kg) simple transfusion rather than partial packed cell exchange. We conclude that although long-term consequences of less aggressive transfusion therapy are unknown, the use of such a regimen may be reasonable, particularly in patients with significant transfusional hemochromatosis.

Adolescent↗
PubMed1991

[Severe hemorrhage in pancreatic pseudocyst].

Pseudocysts in the pancreas occur in 10% of patients with pancreatitis and may lead to serious complications, i.e. infection, obstruction of the bile duct, rupture, and hemorrhage. The last complication is highly lethal. Two patients are described, with differing modes of presentation and therapy. In one patient hemostasis was obtained by surgical packing followed by percutaneous embolization. In the other patient embolization failed and surgical resection was necessary.

Adult↗
PubMed1991

Lipoprotein lipase in human milk: compartmentalization and effect of fasting, insulin, and glucose.

The object of this study was to investigate the effect of maternal metabolic state on the activity of lipoprotein lipase (LPL) in human milk. Although the total LPL activity in milk was not significantly affected by up to three cycles of freezing and thawing, the amount of LPL associated with the cream fraction of the milk increased from an average of less than 10% to about 70% after this treatment. The enzyme was relatively stable when the milk was stored on ice, losing activity at a rate of about 1% per hour. At 37 degrees C degradation was more rapid, about 7% per hour. When LPL activity was measured in samples taken at hourly intervals by breast pump, using oxytocin to achieve a complete letdown at each pumping, activity was found to double from the first to the third pumping. Thereafter the activity was stable under fasting conditions. Hyperglycemic and euglycemic, hyperinsulinemic glucose clamp protocols were used to evaluate the effects of glucose and insulin. Both high plasma glucose and high plasma insulin in the presence of normal glucose significantly increased LPL activity within 4 hours. We conclude that, like adipose, tissue LPL, mammary LPL is regulated by plasma insulin.

Adult↗
PubMed1990

[Charcot-Marie-Tooth disease. Peroneal muscular atrophy].

The classification of Charcot-Marie-Tooth disease is provisional, because the chromosome and gene localization is still not precisely known, and gene products have not been identified. This article presents an analysis of the clinical, genetical and neurophysiological data of eight Charcot-Marie-Tooth patients. The study was carried out to find out if it is possible to classify the disease from neurophysiological and genetical data. We found Charcot-Marie-Tooth disease transmitted autosomal dominant in three cases, whereas no family pattern was apparent in the remaining five. Among the three cases of autosomal dominant transmission, two were of the segmental demyelinization type, and one had axonal neuropathy. The five patients without a distinct family pattern consisted of three with segmental demyelinization and two with axonal neuropathy. Thus, the neurophysiological subdivision did not correlate with the inheritance, which indicates a genetical heterogeneity for the Charcot-Marie-Tooth disease.

Adolescent↗
PubMed1989

Zuclopenthixol and haloperidol/levomepromazine in the treatment of elderly patients with symptoms of aggressiveness and agitation: a double-blind, multi-centre study.

A double-blind study was carried out in 48 hospitalized, elderly demented patients with key symptoms of aggressiveness and agitation to evaluate the efficacy and tolerability of zuclopenthixol compared with that of haloperidol/levomepromazine. Patients were allocated at random to receive initial doses of either 4 mg zuclopenthixol daily or 1 mg haloperidol in the morning and 5 mg levomepromazine in the evening over a period of 4 weeks. In Week 4, the mean daily dose was 4.8 mg zuclopenthixol and 1.6/7.6 mg haloperidol/levomepromazine, respectively. After 1 week, the severity of illness was already significantly reduced, and was further reduced after 2 and 4 weeks of treatment in both groups: the reduction, however, was most pronounced in the zuclopenthixol group and after 2 weeks this difference was significant. Side-effects were few. The results of the study indicate that, whilst both zuclopenthixol and haloperidol/levomepromazine were effective and well tolerated in these elderly patients with aggressiveness and agitation, onset of therapeutic effect appeared more rapidly with zuclopenthixol, which furthermore provides the practical advantage that it may be administered once a day.

Aged↗
PubMed1988

Ultrasonically and fluoroscopically guided therapeutic percutaneous catheter drainage of the gallbladder.

Percutaneous gallbladder drainage was performed in 16 poor surgical risk patients; 13 had acute cholecystitis, 1 had cholangitis and septicemia, 1 had undergone removal of a gallbladder calculus, and 1 had pancreatic carcinoma with bile duct occlusion. Catheterization and drainage of the gallbladder succeeded primarily in all patients. Catheter dislodgement occurred within 24 h in 1 patient without any side effects. One 87-year-old patient died 14 h after the insertion of the catheter from reasons unrelated to the drainage procedure. Percutaneous removal of gallbladder calculi failed in 3 patients, 2 of whom had been successfully treated for cholecystitis by catheter drainage. Percutaneous gallbladder drainage is a fast, low-risk, inexpensive procedure well suited for the treatment of acute, poor surgical risk patients.

Adolescent↗
PubMed1987

Sodium transport and phosphorus metabolism in sodium-loaded yeast: simultaneous observation with sodium-23 and phosphorus-31 NMR spectroscopy in vivo.

Simultaneous 23Na and 31P NMR spectra were obtained from a number of yeast suspensions. Prior to NMR spectroscopy, the yeast cells were Na-loaded: this replaced some of the intracellular K+ with Na+. These cells were also somewhat P-deficient in that they had no polyphosphate species visible in the 31P NMR spectrum. In the NMR experiments, the Na-loaded cells were suspended in media which contained inorganic phosphate, very low Na+, and a shift reagent for the Na+ NMR signal. The media differed as to whether dioxygen, glucose, or K+ was present individually or in combinations and as to whether the medium was buffered or not. The NMR spectra revealed that the cells always lost Na+ and gained phosphorus. However, the nature of the Na+ efflux time course and the P metabolism differed depending on the medium. The Na+ efflux usually proceeded linearly until the amount of Na+ extruded roughly equalled the amount of NH4+ and orthophosphate initially present in the medium (external phosphate was added as NH4H2PO4). Thus, we presume this first phase reflects a Na+ for NH4+ exchange. The Na+ efflux then entered a transition phase, either slowing, ceasing, or transiently reversing, before resuming at about the same value as that of the first phase. We presume that this last phase involves the simultaneous extrusion of intracellular anions as reported in the literature. The phosphorus metabolism was much more varied. In the absence of exogenous glucose, the P taken up accumulated first as intracellular inorganic phosphate; otherwise, it accumulated first in the "sugar phosphate" pool. In most cases, at least some of the P left the sugar phosphate pool and entered the polyphosphate reservoir in the vacuole. However, this never happened until the phase probably representing Na+ for NH4+ exchange was completed, and the P in the polyphosphate pool never remained there permanently but always eventually reverted back to the sugar phosphate pool. These changes are interpreted in terms of hierarchical energy demands on the cells under the different conditions. In particular, the energy for the Na+ for NH4+ exchange takes precedence over that required to produce and store polyphosphate. This conclusion is supported by the fact that when the cells are "forced" to exchange K+, as well as NH4+, for Na+ (by the addition of 5 times as much K+ to the NH4+-containing medium), polyphosphates are never significantly formed, and the initial linear Na+ efflux phase persists possibly 6 times as long.(ABSTRACT TRUNCATED AT 400 WORDS)

Aerobiosis↗