Biomedical subjects
Publications and source records attributed to R Ernst.
OBJECTIVE: Our objective was to deliver live and recorded lectures, with images, over the Internet using streaming media. CONCLUSION: Streaming media are an emerging technology that can deliver live lectures over the Internet using standard PCs and modems. These lectures are also simultaneously recorded and can be played back at any time by individuals with access to the Web.
In a prospective randomised study 30 mongrel rabbits received two standard colon-resections. Three types of drains were tested: (latex-rubber-) Penrose-drains, rubbertube- and silicontube-drains, which were placed in the lower abdomen. As a closed drainage-system the extraperitoneal tip of the drain was placed in a closed subcutis-pocket. One of the two colon-anastomoses also was drained. The findings were recorded on the 7th postoperative day. A single mechanic alteration was found, an ulcer caused by a silicon-drain, that pushed against the abdominal wall. The other signs of mechanic irritation were microscopically unspecified inflammatory reactions to the foreign body drain. There was no ascending infection caused by the drain. All infections came from complications of the colon resections. In contrast to common opinions the drains in the lower abdomen showed no adhesions to the abdominal wall or organs. Only the entrance of the drain into the peritoneum and the cotton-gaze of Penrose-drains showed in nearly all cases adhesions. The large amount of adhesions to the anastomosis-drains came from complications of the colon-anastomoses. As a cause of material, rubber- and latex-rubber-drains showed large fibrin-clots on their surfaces. 7 days after the operation only about 20% of the drains had sufficient function. The rest was occluded by fibrin-clots in the lumen of the drain or the cotton-gaze. Over all there is no difference in changes and effects of the three different types of drains, but silicon as material showed advantages.
OBJECTIVE: To compare computed tomography (CT) with open neck exploration in determining prevertebral invasion by squamous cell carcinoma of the oropharynx or hypopharynx. DESIGN: Retrospective analysis using the findings at open neck exploration and results of histopathologic studies as the criterion standards. SETTING: Tertiary care referral center. PATIENTS: Twenty-nine of 40 patients with advanced squamous cell carcinoma of the oropharynx or hypopharynx treated between January 1, 1986, and December 31, 1994, were selected for analysis based on CT findings of posterolateral extension of the primary tumor placing the prevertebral muscle (PVM) at risk. All study patients had no previous therapy and underwent neck exploration to determine resectability. RESULTS: Overall accuracy of CT in predicting PVM status was 55.2%. The sensitivity of preoperative CT for PVM invasion was 50%; the specificity was 61%. Using an estimate of 21% for the prevalence of PVM invasion, the predictive value of a positive CT scan was 0.254 and the predictive value of a negative CT scan was 0.821. Open neck exploration correctly predicted PVM status in all cases. CONCLUSIONS: Open neck exploration is superior to CT to evaluate possible PVM invasion by squamous cell carcinoma of the oropharynx or hypopharynx. The predictive value of a negative CT scan for PVM invasion is high, so it may be useful in treatment planning. Patients with advanced squamous cell carcinoma of the oropharynx or hypopharynx at risk for PVM invasion who are otherwise surgical candidates should be considered for open neck exploration to determine resectability most accurately.
Protein containing quality control (QC) material in ampoules for blood gas, pH and electrolyte analysers has been manufactured using buffered protein (Bovine Serum Albumine, BSA) solution with sodium bicarbonate and chloride salts. For comparison a similar QC material but without protein was manufactured. Results obtained with ampouled QC material depend on pre-analytical effects, on matrix effects and on the stability of the material. Pre-analytical variation occurs with closed and/or opened ampoules. The shaking rate of the ampoule must be high (vortexing) and the duration of shaking long enough (15 seconds) to give good reproducibility. Temperature coefficients of protein containing controls are equal to those of protein free controls when incubated at different temperatures. Vigorously shaking of the ampoule gives a protein foam layer resulting in stable values for pH, pCO2 and pO2 during maximally 6 minutes after opening of the ampoule. Concerning matrix effects the CO2 buffer capacity of protein containing QC material is slightly higher compared to that of protein free QC materials as determined by tonometry with CO2/air gas mixtures and measuring pH and plotting log pCO2 vs. pH. The O2 buffer capacity measured as the bias on a properly functioning blood gas analyser is smaller than the bias of protein free QC material. The protein containing quality control is stable for at least 12 months when stored refrigerated at 2-6 degrees C and 28 days at room temperature.
We investigated the efficacy of bone marrow (bm) processing by a large-volume apheresis procedure using a self constructed sixfold collection bag system for sequential cell collection and analysis for 5 pediatric patients. Quantitation of leukocytes (WBC), CD34+ cells and colony-forming cells (CFU-GM) within the single bags showed a relative time-dependent decrease of all cell fractions during leukapheresis, whereas the relative amount of mononuclear cells (MNC) droped only slightly. At the same time the large volume apheresis (6 x original bm-volume) clearly enhanced the absolute yield of CD34+ cells compared to the standard procedure (3 x bm-volume) for more than 20%. We conclude that large-volume apheresis for bm processing is an efficient technique to improve the yields of progenitor cells.
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The laparoscopic cholecystectomy of gall bladder carcinoma may have unfortunate consequences because of tumor cell dissemination. In this case report a female patient is presented, where histologically a gallbladder carcinoma was surprisingly diagnosed after laparoscopic cholecystectomy because of symptomatic cholecystectomy. 2 weeks after the first operation tumor cell clusters were found in the laparoscopy tracts.
The bone mineralization of 6 male and 18 female adolescents with a mean age of 12 years and 11 months, who had suffered severe, early, postnatal protein-energy undernutrition, was analyzed. These patients have been followed up at our Institute since their nutritional rehabilitation. Bone mineralization was measured by bone dual isotopic densitometry (Gd 153). These results were compared with those of normal school-age Chilean children of the same age and sex. Weight for height of adolescent who had suffered from undernutrition was similar to the controls, and both were over 100% of the standard. Adequation of height for age was significantly less in those with previous history of undernutrition. Densitometries showed that adolescents with a past history of undernutrition had lower total bone mass in whole body, spine and femoral neck; differences disappeared when expressed per 100 cm of body height. There were no differences in bone mineral density in the different area measurements. It is concluded that the possible alterations that undernutrition produces in bone mineralization probably recover after nutritional rehabilitation, adequate nutritional follow up and health support.
Technetium-99m sestamibi is known to localize in primary malignant and metastatic tumors. Specifically, brain, breast, thyroid, parathyroid, lung, and kidney tumors have been imaged. The Verner Morrison syndrome, which is caused by excessive vasoactive intestinal peptide (VIP), consists of watery diarrhea, hypokalemia, and achlorhydria. This condition is rarely associated with multiple endocrine neoplasia. The authors present a case of multiple endocrine neoplasia type I with visualization of a pancreatic VIPoma and parathyroid adenoma with Tc-99m MIBI.
We have found that an angled tip with a 40-degree angle and a distal length of 1 to 3 mm can be useful in subselecting intracranial vessels whose origins are otherwise difficult to catheterize. In addition, curves can be introduced by shaping the coil introducer as needed. These shapes can be safely formed using a coil introducer inserted in a retrograde fashion and fixed in boiling water.
In a multicenter, placebo-controlled, comparative trial with 196 general practitioners and internists 730 18 to 70 year-old patients with endoscopic evidence of a duodenal ulcer were enrolled. Each group of 365 patients received 150 mg Roxatidine acetate once daily, either late in the evening (bedtime administration, between 10.00 p.m. and 11.00 p.m.) or early in the evening (after dinner, between 6.00 p.m. and 7.00 p.m.). The endoscopic control revealed that the ulcers healed after four weeks of treatment in 74% (bedtime administration) and 77% (administration early in the evening), respectively. There was no significant difference ascertained between both groups. At the last visit, epigastric pain was removed during the day in 86% and during the night in 90% in both groups.
Between 1984 and 1991, antenatal ultrasound scanning detected urinary tract malformations in 126 infants, who were investigated and treated postnatally in the childrens' hospital of the Westfälische Wilhelms-University Münster. 10 out of 126 children with urogenital changes, died in the first hours after birth, due to pulmonary hypoplasia (Potter's sequence), 1 further infant died later after cardiac operation, and another died of megacystic-megaureter-hypoperistaltic-syndrome. In the first months after birth 71 (61%) of 116 infants underwent urological surgery; 12/116 infants (10.3%) had severe bilateral kidney changes, some of them with severe deficiency of amniotic fluid before birth. 6/116 infants (5.2%) had chronic renal insufficiency, 2 of them will have to be dialyzed in early childhood and longterm, 14 patients (12%) are threatened by chronic renal failure. 14 patients (12%) developed severe arterial hypertension, all had to be treated with antihypertensive drugs, in 5 of them hypertension subsided after unilateral nephrectomy, another five had transient hypertension, but four require continued medical treatment. We describe the prenatal ultrasound findings, compared them with diagnosis after birth, illustrate diagnostics, plans of therapy, urological surgical interventions and nephrological consequences. Benefits and limitations of antenatal ultrasonography for the detection of urinary tract malformations and the treatment of those malformations before and after birth are discussed. In utero diagnosis of severe urinary tract abnormalities allows treatment of these infants immediately after birth, furthermore the prevention of severe infections, additional damage of renal tissue, and early diagnosis and treatment of arterial hypertension and metabolic imbalances caused by chronic renal insufficiency in early childhood.
The major metabolite of cannabis found in urine, 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (delta 9-THC), is the compound most often used to calibrate cannabinoid immunoassays. The hydrophobic delta 9-THC molecule is known to adsorb to solid surfaces. This loss of analyte from calibrator solutions can lead to inaccuracy in the analytical system. Because the calibrators remain stable when not used, analyte loss is most probably caused by handling techniques. In an effort to develop an effective means of overcoming adsorption losses, we quantified cannabinoid loss from calibrators during the testing process. In studying handling of these solutions, we found noticeable, significant losses attributable to both the kind of pipette used for transfer and the contact surface-to-volume ratio of calibrator solution in the analyzer cup. Losses were quantified by immunoassay and by radioactive tracer. We suggest handling techniques that can minimize adsorption of delta 9-THC to surfaces. Using the appropriate pipette and maintaining a minimum surface-to-volume ratio in the analyzer cup effectively reduces analyte loss.
From 1988 to 1990, 467 patients were operated a total of 850 times for malignant intra-abdominal tumours. Analysis of these 850 operations revealed that 205 were performed for recurrences with or without metastasis and 59 were performed for metastasis. The operations for recurrences were elective in 158 cases and consisted of 86 local radical procedures and 72 non-radical procedures. 47 operations for recurrences were performed as emergency procedures and were non-radical in 45 cases. With 55 of 59 operations for metastasis the majority of these operations was performed electively and locally radical. The majority for metastases were performed electively and were locally radical. The majority of life-threatening emergency situations were controlled (129 of 141 operations, 92%) and two-thirds of these patients left hospital with a satisfactory quality of life (Karnofsky index > 50 in 83 of the 141 operations). Consequently, repeated operations and the combination of surgery with adjuvant therapy can control malignant disease for several years with a satisfactory quality of life.
Four days after an operation for fusion of lumbar and sacral vertebrae a 30-year-old man developed bilateral deep-vein thrombosis in the legs, extending on the left from the fibular group of veins to the popliteal vein. On the right all deep veins of the lower leg were occluded, including the confluence of the popliteal vein. As systemic fibrinolysis was contraindicated, surgical thrombectomy was undertaken. After incomplete removal of the thrombi, regional hyperthermic perfusion with streptokinase was performed using a heart-lung machine. After a compression bandage had been applied to the right leg above the veins the leg was perfused via the common femoral vein at 40 degrees C from the heart-lung machine, at a flow rate of 600-800 ml/min, for 60 min with a solution containing 1 million IU streptokinase. Measurement of various components in the perfusate indicated marked fibrinolysis (fibrinogen: not measurable; fibrinogen breakdown products: > 80 micrograms; streptokinase: 100 FU/ml after 30 min, 62 FU/ml after 60 min). At the same time there was no demonstrable fibrinolytic activity in the systemic circulation. Fibrinogen concentration fell from 340 mg/dl 30 min before the onset of perfusion to 245 mg/dl 90 min after it. After 60 min of perfusion the blood from the right leg was discarded and the leg flushed through with 1.5 l of an electrolyte solution and then filled up with previously obtained and stored patient's own blood concentrate. Subsequent phlebography and venous occlusion plethysmography demonstrated complete recanalization of the deep-vein system with normal venous valve function.
Microcirculatory effects of electrical stimulation of nerves through a pair of needle electrodes in the skin of anaesthetized pigs were studied by using the laser Doppler flowmetric method. Electrical stimulation (0.3-30 Hz) evoked a short-lasting decrease in capillary blood flux (vasoconstriction) followed by an increase (vasodilatation), of longer duration. Vasoconstriction was inhibited by local guanethidine, but not by capsaicin pretreatment, whereas vasodilatation was blocked by local capsaicin, but not by guanethidine. Both phases of the response were suppressed by local application of tetrodotoxin. Thus, vasoconstriction due to electrical stimulation seems to be of sympathetic origin, while vasodilatation is a result of a release of vasoactive substances from capsaicin-sensitive nerve endings. Vasodilatation due to electrical stimulation was strongly and dose-dependently inhibited by the opioid peptide [D-Met2,Pro5] enkephalinamide, while vasoconstriction remained apparently unchanged. At both doses of the opioid peptide tested (0.03 and 0.15 mumol/kg i.m.) inhibition of vasodilatation was larger at lower than at higher frequencies of stimulation. Guanethidine pretreatment did not influence the inhibitory action of [D-Met2,Pro5] enkephalinamide. Naloxone (1.5 mumol/kg i.m.) reversed or prevented the inhibitory action of the opioid peptide; naloxone on its own did not influence responses due to 0.3-30 Hz stimulation. [D-Met2,Pro5] enkephalinamide (0.15 mumol/kg i.m.) did not influence basal blood flux in the skin, mean arterial blood pressure, respiratory minute volume or respiratory frequency. It was concluded that stimulation of opioid receptors by [D-Met2,Pro5] enkephalinamide is likely to inhibit stimulation-evoked vasodilatation by reducing the release of vasoactive substances from capsaicin-sensitive afferent neurons, an effect that does not depend on functional integrity of sympathetic nerves. Endogenous opioids probably do not modulate the capsaicin-sensitive vasodilatation.
Vascular changes in resected bowels of Crohn's disease were examined angiographically, microangiographically, micro-preparatorily and histologically. The proper angioarchitecture of the small and the large bowel is being destroyed in the course of the ongoing inflammatory process. Dilated capillaries, destruction of the primary angioarchitecture and its replacement by an irregular, partially bizarre pattern of scar vessels with bundling of the unchanged Vasa recta as varying vessel diameters caused by obliterating secondary fibroses can be seen in advanced Crohn's disease. The angioarchitecture of the pseudo-polyps in Crohn's disease is characterized by an increased number of vessels, bizarrely bended vessels and a radial pattern of veins. All these vascular changes in Crohn's disease are to be seen as secondary changes due to the inflammatory reaction.
Eighty-nine newborns and infants with congenital urinary tract malformations were treated in the childrens' hospital of the Westfälische Wilhelms-University from 1986 to 1989. Twenty patients of this group (22.5%) developed severe hypertension requiring treatment within the first year of life. Mean age of diagnosis of hypertension was 5 months (range 0.5-12 months). Median values for blood pressure at time of diagnosis were 138 mmHg (range 120-170) for systolic and 92 mmHg (range 80-110) for diastolic values. Six patients showed characteristic symptoms for hypertension such as restlessness, sweating and sleep disorders. Plasma levels of renin were obtained in 12 of 20 patients. Five patients had raised plasma renin levels. All patients with a severe hypertension were treated with one to several antihypertensive drugs. Risk factors for the development of severe renal hypertension in early infancy are cystic renal malformation, vesico-ureteral reflux, obstructive uropathy and to our experience also short term percutaneous nephrostomy in obstructive uropathy in particular in connection with pyelonephritis. Hypertension can still appear after the successful surgical correction of urinary obstruction. We describe the group of patients with severe hypertension in our study group; diagnostic principles and our therapeutic approach are explained. We conclude that early diagnosis of severe hypertension and consecutive treatment are important in infants with congenital urinary malformations.