Does intravenous ondansetron affect gastric emptying of a solid meal, gastric electrical activity or blood hormone levels in healthy volunteers?

BACKGROUND: In previous studies, tropisetron has been shown to accelerate gastric emptying of a solid meal. However, it is uncertain whether other specific 5-hydroxytryptamine-3 receptor antagonists, such as ondansetron, also have a gastroprokinetic effect in humans. AIM: To evaluate the effect of ondansetron on gastric half-emptying time (T1/2) of a solid meal, gastric myoelectrical activity and hormone levels in 14 healthy volunteers. METHODS: In a placebo-controlled, randomized, crossover study, we investigated the effects of ondansetron (8 mg intravenously) on the gastric emptying of solids (by scintigraphy), gastric myoelectrical activity (by electrogastrography) and the post-prandial release of cholecystokinin, gastrin, human pancreatic polypeptide, gastric inhibitory polypeptide, vasoactive intestinal polypeptide, motilin, substance P and galanin. RESULTS: The average T1/2 values were 86 min and 85.5 min without lag time (P=0.082) and 92 min and 93 min with lag time (P=0.158) for the placebo and ondansetron treatments, respectively. The average T1/2 of female volunteers was significantly longer than that of male volunteers. The dominant gastric electrical frequency and hormone plasma concentrations were not altered by ondansetron. CONCLUSIONS: Ondansetron did not affect the gastric emptying of solids, the dominant gastric electrical frequency or the plasma concentrations of the analysed gastrointestinal peptides.

Deactivation of thalamocortical activity is responsible for suppression of parkinsonian tremor by thalamic stimulation: a 99mTc-ECD SPECT study.

Four patients with Parkinson's disease (PD) achieved excellent improvement of their unilateral tremor by chronic deep brain stimulation (DBS) of the contralateral ventral intermediate (Vim) nucleus of the thalamus. Repeated measurements of cerebral blood flow were obtained 14 days apart off and on stimulation using 99mTc-ECD SPECT. Subjects were scanned at rest and the data were compared with those of normal healthy volunteers. During stimulation, there were highly significant deactivations in the motor area and supplementary motor area on the electrode side and in the prefrontal area and the anterior cingulum bilaterally. No cerebellar deactivation was detected. We conclude that the mechanism responsible for suppression of parkinsonian tremor by thalamic stimulation is deactivation of thalamocortical activity.

Implementation of pulse-coupled neural networks in a CNAPS environment.

Pulse coupled neural networks (PCNN's) are biologically inspired algorithms very well suited for image/signal preprocessing. While several analog implementations are proposed we suggest a digital implementation in an existing environment, the connected network of adapted processors system (CNAPS). The reason for this is two fold. First, CNAPS is a commercially available chip which has been used for several neural-network implementations. Second, the PCNN is, in almost all applications, a very efficient component of a system requiring subsequent and additional processing. This may include gating, Fourier transforms, neural classifiers, data mining, etc, with or without feedback to the PCNN.

Finding the shortest path in the shortest time using PCNN's.

A pulse coupled neural network (PCNN) can run mazes nondeterministically (taking all possible paths) with constant time per step. Thus, when a signal emerges, it has taken the shortest path in the shortest time.

Inherent features of wavelets and pulse coupled networks.

Biologically inspired image/signal processing like the pulse coupled neural network (PCNN) and the wavelet (packet) transforms are described. The two methods are applied to two-dimensional data in order to demonstrate the features of each method, pinpoint differences as well as similarities. The inherent properties (with respect to filtering, segmentation, etc.) of the two approaches with respect to detectors for physics experiments as well as remote sensing are discussed.

Foveation by a pulse-coupled neural network.

Humans do not stare at an image, they foveate. Their eyes move about points of interest within the image collecting clues as to the content of the image. Object shape is one of the driving forces of foveation. These foveation points are generally corners and, to a lesser extent, the edges. The pulse-coupled neural network (PCNN) has the inherent ability to segment an image. The corners and edges of the PCNN segments are similar to the foveation points. Thus, it is a natural extension of PCNN technology to use it as a foveation engine. This paper will present theory and examples of foveation through the use of a PCNN, and it will also demonstrate that it can be quite useful in image recognition.

Primary cervical malignant teratoma with a rib metastasis in an adult: five-year survival after surgery and chemotherapy. A case report with a review of the literature.

We report a case of a man presenting with a cervical malignant teratoma and a chondrosarcomatous rib metastasis. He was alive and free of recurrence five years and 10 months (= 70 months) after resection of the primary mass, followed by chemotherapy and subsequent resection of the rib tumor. This is the 35th patient reported in the literature and the first description in which an 'adjuvant' or primary chemotherapy was used. Previous patients with a cervical malignant teratoma, reported after lethal outcome, had survivals of one to 22 months (median nine months). In all patients with a preoperative clinical impression of an aggressive, differentiated or undifferentiated malignancy, the definite diagnosis of teratoma could only be made histologically. By analogy to germ cell tumors, the prognosis of malignant teratoma might be improved if complete excision is combined with new, adjuvant chemotherapy protocols for germ cell tumors. Lessons learned from this case are placed in the context of germ cell tumors in general and of non-gonadal malignant teratomas in particular.

Diagnostic angioscintigraphic evaluation of malignant hepatic tumors before catheter embolization: determination of shunt, flow distribution, and reflux.

PURPOSE: The aim of this study was to evaluate quantitatively arteriovenous shunts in malignant liver tumors by injection of 99mTc macroaggregates of albumin (MAA) into the tumor-feeding artery after selective catheterization. METHODS: In 40 patients with malignant liver tumors (33 hepatocellular carcinomas and 7 metastases of colorectal cancer), a mean dose of 200 MBq 99mTC MAA was injected arterially during angiography. The embolized area and the lungs were then visualized using a gamma camera. A dedicated computer program calculated pulmonary shunt rates. RESULTS: The majority of patients (n = 30) with hepatocellular carcinoma showed small shunts varying from 0 to 15%; only 3 of these patients had shunts ranging from 18% to 37%. In patients with colorectal carcinoma metastases (n = 7) the shunt varied from 0 to 3% (2 +/- 1%), probably due to a physiological shunt in normal liver tissue in the embolized area. Importantly, the degree of shunt found bore no correlation to the tumor volume or to the pattern of vascularity on angiography. CONCLUSION: Diagnostic angioscintigraphy is a useful tool for pretherapeutic evaluation of the capacity of an individual tumor to retain particles and to measure extratumoral shunting; these are essential for therapy planning, as they can help to increase the safety and effectiveness of embolization.

[Long-term course of medullary thyroid gland carcinoma]. / Langzeitverlauf des medullären Schilddrüsenkarzinomes.

UNLABELLED: To obtain information on the outcome of medullary thyroid carcinoma (MTC) in the Berne area, a retrospective analysis of the 28 MTCs diagnosed by the Institute of Pathology of the University of Berne in the 25-year period between 1969 and 1994 was done. These 28 MTCs represented 2.4% of all thyroid malignancies diagnosed at the Bernese Institute of Pathology in the 25-year period mentioned above. 25 MTCs were sporadic and 3 associated with a multiple endocrine neoplasia (MEN) syndrome. Follow-up data were available from 27 of the 28 MTC patients. After a follow-up period of between 2 and 275 months 7 of these 27 patients had died form the MTC (among them all 4 patients with T4 tumors) and two were alive with tumor. 18 patients, including all 14 patients with T1 or T2 tumors without lymph node or distant metastases at the time of diagnosis, were alive and without evidence of tumor at the end of the follow-up period. CONCLUSIONS: MTCs are rare malignant tumors and comprise only a small fraction of all thyroid carcinomas in the Berne area. Most MTCs were sporadic, only a small minority was associated with a MEN syndrome. The TNM stage was the most important prognostic factor for patient survival. These data are in accordance with the results of similar MTC surveys done in other areas.

Noninvasive differentiation of meningiomas from other brain tumours using combined 111Indium-octreotide/99mtechnetium-DTPA brain scintigraphy.

We have studied prospectively 47 patients with CNS tumours including 16 meningiomas and 33 other tumours using combined 111In-octreotide and 99mTc-DTPA brain scintigraphy. 111In-octreotide scintigraphy was used to image somatostatin receptors (SSR) and 99mTc-DTPA scintigraphy was used to assess the integrity of the blood-brain barrier (BBB). A total of 32 tumours (65%) were detected. All SSR positive tumours also had positive 99mTc-DTPA scans and all SSR negative tumours were negative on 99mTc-DTPA scans. Among the tumours located outside the BBB, all meningiomas and two out of six schwannomas were positive on combined SSR/99mTc-DTPA scintigraphy. Among the tumours located inside the BBB, seven out of nine gliomas grade I-III were negative, whereas all glioblastomas were positive. Other positive tumours included one malignant non-Hodgkin lymphoma and two cerebral metastases. SSR scintigraphy alone was non-specific in the diagnosis of meningiomas, as 16 non-meningiomatous tumours also had positive SSR scans probably due to a breakdown of the BBB (excluding the malignant lymphoma). Measuring the tumour-to-background ratio on SSR scans improved specificity, but sensitivity was decreased below 70% because some meningiomas were only slightly positive. Only the ratio of SSR scintigraphy to conventional 99mTc-DTPA brain scintigraphy (SSR-to-BS index) allowed a reliable differentiation of meningiomas from other CNS tumours, most notable from schwannomas (sensitivity: 94%; specificity: 100%). Our results support the usefulness of combined SSR and conventional brain scintigraphy in the noninvasive pre-operative diagnosis of meningiomas.

Optical syntactic pattern recognition by fuzzy scoring.

A novel syntactic approach is introduced to treat particular problems in pattern recognition. The procedure is implemented by the use of optical correlation methods for identifying the various primitives that appear in the input pattern, and their importance is determined by fuzzy relational scoring. Robust pattern recognition with tolerance to normal variations is demonstrated, indicating an efficient new approach for optical pattern recognition.

[Risk factors in papillary thyroid cancer]. / Risikofaktoren beim papillären Schilddrüsenkarzinom.

270 patients with papillary thyroid carcinoma were retrospectively analyzed. The mean age at initial diagnosis was 43.5 years. 74% of the patients were females. 15 patients (6%) had residual tumor after initial surgery and 61 patients (24%) showed recurrent disease. The recurrence was discovered clinically, radiologically and by increasing thyroglobulin levels in 72%, 23% and 5% of the patients, respectively. Recurrent disease was located in the tumor bed, locally and metastatic and only metastatic in 61%, 23% and 16% of the patients, respectively. After a mean follow-up of 9.4 years (range 3-20 years) the overall mortality was 13%. 6% of the patients died from tumor, 3% with tumor and 4% without tumor. 46% of patients with residual tumor died from tumor progression, in contrast to 18% of patients with early recurrence (< 5 years) and 6% of patients with late recurrence (> 5 years). We conclude that papillary thyroid carcinoma has a low mortality (6%) even in an endemic area. Patients with residual tumor after initial surgery and patients with early recurrence have an increased cancer mortality.

[Long-term course in differentiated thyroid gland carcinoma]. / Langzeitverläufe beim differenzierten Schilddrüsenkarzinom.

545 patients with differentiated thyroid carcinoma were followed up for periods ranging up to 25 years after first treatment (mean 8.1 years, 65% for over 5 years). 72% of patients with papillary carcinoma (n = 270), but only 52% with follicular carcinoma (n = 275) remained tumor-free during the further course. Residual malignancies persisted for more than the first year in 6% and 17% of patients respectively; there were tumor recurrences after an apparently tumor-free interval in 22% and 31% respectively, the latest after 12 and 27 years respectively. 6% and 19% of patients respectively died as a direct result of the tumor (and a group of equal size from other causes), half due to residual and half due to recurrent carcinoma. With regard to residual tumors, few significant risk factors were found preoperatively, comprising distant metastases (factor = 34 and 20 for papillary and follicular tumors respectively), age over 50 years (F = 6.4 and 5), infiltrating growth of primary tumor (F = 4 and 4.3), and regional lymph node involvement (F = 1.2 and 2). However, these factors were of little use in predicting the risk of the more frequently observed tumor recurrence, with maximum factors of 2 (for T4 and N+ stage) for papillary thyroid cancers and 1.5 for follicular cancers. At risk for recurrence were patients in whom total thyroidectomy was not performed (F = 2.3 and 2) and those who did not receive postoperative radioiodine treatment (F = 3), irrespective of age and tumor stage. Therefore, any individualizing regimen beginning with the first treatment has a bearing not only on residual tumor's 50% contribution to mortality. The equally large contribution of recurrences to tumor death can be influenced only by thyroidectomy or, more realistically, by strumectomy combined with early ablation of thyroid remnants with radioiodine. Postoperative radiotherapy of the neck region did not prevent tumor recurrence, and although hormonal suppression was never given the results compared well with the best of published long-term follow-up studies. There were no acute or late complications that could be ascribed to radioiodine treatment. However, a strict strategy of the reducing the administered doses was adopted: the ablation dose was half that used previously (1.5 GBq, i.e. 45 mCi on average), tumor treatment was halted even where residual uptake was observed scintigraphically (in 44% of patients treated) and radioiodine was no longer used for follow-up investigations.(ABSTRACT TRUNCATED AT 400 WORDS)

Nonimmunogenic hyperthyroidism: cumulative hypothyroidism incidence after radioiodine and surgical treatment.

During 1977, 246 hyperthyroid patients were seen in our departments, 140 (57%) with nonimmunogenic hyperthyroidism (NIH)--101 with a toxic adenoma (TA) and 39 with multifocal functional autonomy (MFA). All patients but one could be followed over 9 yr, 101 after 131I treatment (RIT), another 29 after surgery (S). Ten patients were left untreated. Thirty-four treated (24%) patients died, none as a result of thyroid or post-treatment complications. There was no hyperthyroidism later than 9 mo after therapy. Only 1% (RIT) and 24% (S) were hypothyroid 1 yr after treatment. But 19% of all treated NIH patients were hypothyroid after 9 yr or at the time of their death, 12% after RIT and 41% after S. The cumulative hypothyroidism incidences 1.4%/yr for RIT and 2.2%/yr for S, were not significantly different. Out of the five survivers without RIT or S, two TA patients were hypothyroid. The effect of RIT on goiter related loco-regional complications was not worse than after S. We conclude that RIT is the treatment for NIH, leaving surgery for exceptional cases.

Observations on blood pressure measurements in high-school athletes.

The purpose of this study is to identify possible evidence of hypertension in athletic adolescents. In addition to sex and age, the effects of various physical factors that may influence blood pressure are measured. The data were collected from the annual screening physicals of local high-school athletic program participants. Nine of the 11 measured physical factors account for 10 percent to 20 percent of the variability in blood pressure measurements. These include age, weight, height, pulse, quadriceps girth, heel cord flexibility, jump reach, hang time, and grip strength. These variables are incorporated into formulae that adjust the range of "normal" values of systolic and diastolic blood pressure to reduce the effects of these confounding factors, thereby increasing the accuracy of the "normal" or "hypertensive" determination for each individual.

Design for a massive all-optical bidirectional associative memory: the big BAM.

An optical bidirectional associative memory offering a potential of operating up to 10(6) neurons with 10(12) interconnections is described. Except possibly for input and output all operations are optical and parallel.

[Surgical treatment of hyperthyroid struma: surgery results, postoperative long-term course and study of a factor connected with recurrences]. / Die chirurgische Therapie der hyperthyreoten Struma: Operationsresultate, postoperativer Langzeitverlauf und Untersuchung einiger mit dem Auftreten von Rezidiven zusammenhängender Faktoren.

None of the 335 patients thyroidectomized for hyperthyroidism in our department of surgery between 1972 and 1982 died as a consequence of the operation. Reassessment of 226 of these patients by questionnaire 68 +/- 25 (SD) months after thyroidectomy revealed the following complications: postoperative paresis of the recurrent nerve (9%), persistent change of voice (2%), and persistent hypoparathyroidism (3.5%). 91 patients underwent a follow-up investigation 74 +/- 33 months after thyroidectomy. Only one had recurrent hyperthyroidism but 6 had a recurrence of the goiter. Patients with recurrent goiters had a significantly higher frequency of increased serum thyroglobulin levels than patients without goiters. These results emphasize the effectiveness of surgical therapy in hyperthyroidism, and suggest that serum thyroglobulin might be a useful predictor for goiter recurrence.

A diagnostic approach to lytic lesions of the mandible.

Fifty seven patients with histologically proven cyst-like lesions of the mandible are reviewed. The importance of combining radiographic with scintigraphic imaging is stressed. These two imaging modalities are complementary in demonstrating both the biological activity and the extent of the lesion. In osteomyelitis the bone scan, which is more sensitive than the radiograph, is also the method of choice in assessing the result of treatment.

A modification of the 133Xe inhalation method for the measurement of liver blood flow in man.

The 133Xe inhalation technique for liver blood flow measurements was modified by using a gamma camera for data acquisition. Desaturation curves were derived from regions of interest (ROIs) over different parts of the liver, the lung and that lung area overlapping the liver, the liver hilus, and the splanchnic area. An additional liver scan with 99mTc-sulfur colloid facilitated the choice of these regions and allowed the estimation of the total liver volume. Thirteen healthy volunteers were examined under baseline conditions. Uncorrected blood flow values derived from the 133Xe-washout curves over the liver (40 +/- 10 ml/min/100 g liver) were lower than those found with other methods. A multicompartment model, based on the input functions calculated from the lung and splanchnic curves, gave values in accordance with those reported in the literature (94 +/- 20 ml/min/100 g or 1,356 +/- 382 ml/min/liver; mean liver volume: 1,475 +/- 227 g). Some methodologic limitations are shared with other invasive or noninvasive techniques.