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Biomedical subjects

P Huber

Publications and source records attributed to P Huber.

At least 91 records · Page 5Linked to original sources
PubMed1994

Enrichment of fetal cells from maternal blood by high gradient magnetic cell sorting (double MACS) for PCR-based genetic analysis.

For simple and effective isolation of fetal cells from peripheral maternal blood, we combined depletion of maternal cells and enrichment of fetal cells by high-gradient magnetic cell separation (MACS). First CD45+ and CD14+ cells were depleted from maternal peripheral blood mononuclear cells by MACS. From the depleted fraction, CD71+ erythroid cells were enriched up to 80 per cent by MACS. This double-MACS' procedure yielded an average depletion rate of 780-fold and an average enrichment rate of 500-fold, with approximate recovery rates of 40-55 per cent. For paternity testing, cells from unseparated blood and the various fractions were analysed for polymorphism of the HLA-DQ-A1 locus and D1S80 locus by the polymerase chain reaction (PCR). In CD45-/CD71+ sorted cells from maternal blood, but not in unfractionated cells from maternal blood or CD45-/CD14- cells, paternal alleles could be detected. In the CD45-/CD71+ fraction, the relative frequency of paternal alleles compared with maternal alleles ranged from 1 in 20 to 1 in 200 (determined by titration and depending on the quality of separation and biological variation). In 7 out of 11 cases, between weeks 12 and 25 of gestation, we could identify paternal alleles by PCR, either HLA-DQ-A1 or D1S80. This double-MACS procedure is simple, fast, efficient, and reliable for non-invasive prenatal diagnosis.

Antigens, CD↗
PubMed1994

Formation and resolution of human peritumoral brain edema.

In 16 patients with 21 metastatic brain tumors and 9 patients with a malignant glioma, tumor volume, volume of the edematous tissue, edema production, speed of edema propagation and edema resolution were examined by using the CT. Edema production was determined according to a technique described previously and ranged between 0.09 and 1.63 ml/h in metastases and between 0.42 and 3.49 ml/h in gliomas. The speed of edema propagation ranged from 0.2-2.2 mm/h. Edema resolution can take place within the tissue (i.e. reabsorption into blood) as well by drainage into the ventricular or subarachnoid CSF. In a few small metastases with a small perifocal edema (without contact to the ventricule or the subarachnoid space) the amount of edema resolution within the tissue could be determined and averaged 0.0086 ml/h/cm3. This probably represents the reabsorption of edema fluid into capillaries within the edematous tissue. If this value is used to calculate the edema reabsorption in larger tumors, the resulting data are considerable lower than the respective edema production rate of that tumor. This indicates, that in larger tumors the main fraction of the edema fluid is draining into the ventricular and/or subarachnoid CSF.

Blood-Brain Barrier↗
PubMed1994

Dural arteriovenous fistula in the falx cerebri.

The case of a 73-year-old patient with a pure dural arteriovenous fistula within the falx cerebri, first manifested as subarachnoid and intraventricular haemorrhage is reported. There was no positive history for both the congenital and the acquired type of lesion. Computed tomographic findings and the relatively unusual angiographic features are discussed.

Aged↗
PubMed1994

Acute peritoneal dialysis in preterm newborns and small infants: surgical management.

Experience with acute peritoneal dialysis gathered over the last 10 years shows that, in 63 premature newborns and infants (up to 1 year of age), a standardized surgical procedure using a silicone catheter with a Dacron cuff (individually glued to fit) has a lower complication rate and is more effective than placement of a trocar catheter.

Acute Kidney Injury↗
PubMed1994

In vivo detection of ultrasonically induced cavitation by a fibre-optic technique.

The measurement of cavitation events in tissue in vivo would greatly assist us to better understand how pulsed high energy ultrasound (PHEUS) interacts with living tissues, especially with regard to cancer therapy. To accomplish this, we designed and built a fibre-optic hydrophone. The principle was to couple the light of a laser diode into a lightfibre and to register the ultrasound induced modification of the refractive index in tissue. In this manner, the cavitation event could be quantitatively investigated both in water and in vivo. The structure of the bubble dynamic is in reasonable agreement with theoretical predictions, and in vitro measurements. With the fibre-optic set-up, the pressure signal can also be detected. PHEUS was generated by an electromagnetic source adapted from a commercial lithotripter (Lithostar Siemens). As biological tissue we used the experimental R3327-AT1 Dunning prostate tumor growing subcutaneously in the thigh of male Copenhagen rats. The lifetime of the cavitation bubble in water increased with the energy level of the ultrasonic pulse from 250 microseconds at 13 kV capacitor voltage to 750 microseconds at 21 kV, while the lifetime inside the tumor tissue in vivo increased only from 100 microseconds at 13 kV to 220 microseconds at 21 kV capacitor voltage.

Animals↗
PubMed1993

Weight loss in patients with hematological neoplasias is associated with immune system stimulation.

Weight loss is the main symptom of so-called tumor cachexia. The pathogenetic mechanisms underlying cachexia are poorly understood; however, it appears that enhanced formation of cytokines such as interferon-gamma and tumor necrosis factor-alpha are involved. In 94 patients suffering from hematological neoplasias we compared body weight changes with serum neopterin, tryptophan, and kynurenine. Biochemical changes, the formation of neopterin, the degradation of tryptophan are closely related to interferon-gamma activity. The majority of our patients had increased neopterin and decreased tryptophan concentrations. Weight loss was seen particularly in patients with higher neopterin and lower tryptophan values. An association between higher neopterin levels and greater weight loss was apparent at study entry and during the follow-up of patients. Our data support the concept that weight loss is closely linked to endogenous interferon-gamma activity.

Biomarkers↗
PubMed1993

Morphological and haemodynamic aspects of cerebral aneurysms.

4 patients with aneurysms of different size and location were examined by cerebral angiography, computed tomography, angio-computed tomography, magnetic resonance imaging and angiography, in order to demonstrate haemodynamic and morphological aspects of cerebral aneurysms. Turbulent flow within aneurysms could be shown by cerebral angiography and magnetic resonance angiography. In contrast MRI or computed tomography are necessary to visualize additional thrombosed parts. MRI is the method of choice to reflect the formation of thrombus, CT to show possible calcifications.

Adult↗
PubMed1993

Serum soluble tumour necrosis factor receptor 55 is increased in patients with haematological neoplasias and is associated with immune activation and weight loss.

Enhanced concentrations of soluble forms of the receptor for tumour necrosis factor (TNF)-alpha have been detected in the serum of cancer patients. We determined serum concentrations of soluble TNF receptor p55 (sTNF-R55) in patients with haematological neoplasias, 50 patients suffering from non-Hodgkin's lymphoma (n = 35), Hodgkin's disease (n = 10) and multiple myeloma (n = 5). Compared with healthy controls and with patients with potential thyroid disease, significantly elevated concentrations of sTNF-R55 were found (mean +/- standard error: 2.68 +/- 0.22 vs. 1.23 +/- 0.21 ng/ml, P < 0.0001 and 2.18 +/- 0.32 ng/ml, P = 0.03). Likewise, neopterin concentrations were raised (19.6 +/- 3.66 vs. 5.3 +/- 0.25 nmol/l in controls, P < 0.0001). We found a significant correlation between sTNF-R55 and neopterin concentrations (Rs = 0.544, P < 0.001). Patients with weight loss showed higher sTNF-R55 concentrations than patients with stable weight. Our results confirm the relevance of sTNF-R55 concentrations in serum of patients with cancer.

Biopterins↗
PubMed1993

Cranial nerve palsies in spontaneous carotid artery dissection.

Two patients had isolated unilateral cranial nerve palsies due to spontaneous internal carotid artery (ICA) dissection without ischaemic cerebral involvement. One had acute glossopharyngeal and vagal, the other isolated hypoglossal nerve palsy. Reviewing all reported cases of angiographically confirmed ICA dissection in the literature, 36 additional cases with unequivocal ipsilateral cranial nerve palsies were analysed. While an isolated palsy of the IXth and Xth has not been reported previously, palsies of the XIIth nerve or the IXth to XIIth nerves were most frequently found. In these patients, lower cranial nerve palsies are probably the result of compression by an enlarging ICA due to mural haematoma. Symptoms and signs indicative of carotid dissection were concurrently present only in some reported cases. This raises the question of unrecognised carotid dissection as a cause of isolated cranial nerve palsies. When the dissection occurs in the subadventitial layer without relevant narrowing of the arterial lumen and when an aneurysm is thrombosed, angiography does not reliably yield the diagnosis. Therefore, carotid dissection might have been underestimated as a cause of isolated lower cranial nerve palsies before the advent of MRI. MRI demonstrates directly the extension of the wall haematoma in the axial and longitudinal planes. Some arteriopathies such as fibromuscular dysplasia and tortuosity make a vessel predisposed to dissection.

Adult↗
PubMed1993

Implementation of practice guidelines in a clinical setting using a computerized knowledge base (Iliad).

We present the implementation of the indications for surgery for three surgical operations--cholecystectomy, cataract extraction, and knee arthroscopy--in a medical expert system, called Iliad. This implementation operates in the preauthorization service of IHC Health Plans (an insurance company in Salt Lake City) as a basis for reimbursement of services. Patient data collection forms, derived from Iliad knowledge base, were used by 13 participating surgeons to document the objective patient observations that justify the surgery and, then were faxed to IHC where a trained nurse input the data in Iliad. Iliad's decisions and reports on any deviations from guidelines are communicated back to the care provider. The study evaluates the impact of the computerized implementation on process, as measured by a questionnaire, and on outcome as measured by rate of approvals, documentation level, rate of requests, and average cost. The prospective implementation of the computerized guidelines has performed reliably, has been perceived as a preferred alternative to the old preauthorization system, and, most importantly, has enhanced significantly the level of documentation permitting evaluation and determination of appropriateness before surgery.

Arthroscopy↗
PubMed1993

Effect of phospholipids and bile acids on cholesterol nucleation time and vesicular/micellar cholesterol in gallbladder bile of patients with cholesterol stones.

Supersaturation and rapid nucleation of cholesterol in bile are of key importance in the pathogenesis of cholesterol gallstones. While the effects of bile acids and phospholipids on cholesterol saturation of bile have been extensively studied, their influence on the cholesterol nucleation time has not been compared. We, therefore, investigated whether increases of bile acid or phospholipid concentrations in bile by in vitro supplementation affect the cholesterol nucleation time. Bile samples were obtained at surgery from patients with cholesterol gallstones. Prior to the nucleation assay the bile samples were divided into 0.5-ml aliquots and supplemented with 1.25, 2.5, 5.0, and 10.0 mumol/ml of different phosphatidylcholines (PC-dimyristoyl, PC-dipalmitoyl, PC-distearoyl, and extracted biliary PCs) or with 5.0, 10.0, and 20.0 mumol/ml of bile acids (glycine or taurine conjugates of cholic acid, deoxycholic acid, or chenodeoxycholic acid). The increase of phosphatidylcholine or bile acid concentration decreased the mean cholesterol saturation index to a similar extent (PC: 0.1-0.3; BA: 0.1-0.2). Supplementations of bile with increasing amounts of synthetic or biliary PCs caused a marked prolongation of the nucleation time in bile from 1.5 +/- 0.2 up to > or = 21 days or 2.5 +/- 0.7 up to > or = 21 days. Concurrently, biliary cholesterol was shifted from vesicles to mixed micelles and the cholesterol/phospholipid ratio of the remaining vesicles was progressively lowered. In contrast, the addition of bile acids to gallbladder bile did not affect the cholesterol nucleation time (2.2 +/- 0.3 days), the percentage of vesicular cholesterol, or the cholesterol/phospholipid ratio of vesicles and micelles.(ABSTRACT TRUNCATED AT 250 WORDS)

Bile Acids and Salts↗
PubMed1993

Technique and clinical results of endorectal surgery.

At the Surgical Department of the University of Cologne, a new system has been developed for transanal endoscopic surgery that allows all the conventional surgical techniques within the entire rectal cavity. The method has been in clinical use since 1983. The main indication is the removal of sessile adenomas. Early rectal carcinomas with favorable histologic grading (grades 1 and 2) and staging (Mason I and II) are also suitable for the method. Advanced cancers can also be removed endoscopically in one session, but we perform local excisions of advanced cancers only in cases in which the patient is unwilling to undergo extensive surgery. During the period from July 1983 to December 1990, this method has been employed on 233 patients in 251 cases. The intraoperative and postoperative course of 236 (94%) operations out of 251 was free from any complications. Early postoperative complications consisted of intraperitoneal perforations (five cases), rectovaginal fistulas (four cases), hemorrhages (four cases), and death as a result of cardiopulmonary failure (two cases). The recurrence rate of adenomas is 4.9%. Endorectal surgery allows endoscopic local transanal excision of large adenomas and early cancers with minimal morbidity and excellent presentation of specimens for complete histologic analysis.

Adenoma↗
PubMed1992

[Evaluation of TSH suppression using a 3d-generation TSH assay: diagnostic and therapeutic consequences].

UNLABELLED: We measured basal and TRH-stimulated TSH values with a 3rd generation assay in patients under suppressive thyroxine (T4) therapy for thyroid carcinoma or goiter and in patients with overt hyperthyroidism. All hyperthyroid patients had undetectable basal TSH levels (< 0.01 mU/l). In patients on suppressive T4 treatment basal TSH values were undetectable in 37.5% (= group A) and measurable in the intermediate range of 0.01-0.05 mU/l in 62.5% (= group B). After TRH administration there was no TSH increase in the hyperthyroid patients (< 0.01 mU/l in 100%). T4-treated patients of group A showed no relevant TSH stimulation in 58% (peak < or = 0.05 mU/l = total TSH suppression). An increase of > 0.05 mU/l could be measured in 42% of group A and 100% of group B (= subtotal TSH suppression). Many of these TSH values measured by a 3rd generation assay are in the undetectable range for most of the commercially available 2nd generation assays (< 0.10 mU/l). CONCLUSION: TSH assay of the 3rd generation decisively improves the diagnosis of hyperthyroidism and probably also borderline hyperthyroidism. Against the background of increased risk of osteoporosis and cardiac function disorders as a result of suppressive T4 treatment, our results suggest the following practical therapeutic guidelines: total TSH suppression with the risk of iatrogenic hyperthyroidism should be confined to high risk patients (eg with metastatic thyroid cancer). Where the risk is low, however (thyroid cancer with favourable prognosis, goiter, goiter prophylaxis), only subtotal TSH suppression is indicated.

Adult↗