Biomedical subjects

J Schipper

Publications and source records attributed to J Schipper.

152 records · Page 9Linked to original sources

PubMedDate not supplied

Color Doppler imaging of paragangliomas in the neck.

PURPOSE: In this study, we describe the color Doppler imaging findings in carotid body tumors and vagal body tumors. METHODS: B-mode and color Doppler imaging were performed on 17 patients who had a total of 25 previously diagnosed paragangliomas (14 carotid body tumors and 11 vagal body tumors). RESULTS: Nineteen of 25 tumors were depicted. Five small vagal body tumors in the region of the nodose ganglion and 1 carotid body tumor could not be depicted. With B-mode imaging, paragangliomas appeared as well-defined, solid, hypoechoic masses. With color Doppler imaging, hypervascularity with a low-resistance flow pattern was demonstrated in all but 1 of the 19 tumors. CONCLUSIONS: The use of color Doppler imaging in the workup of an ambiguous neck mass is advocated.

Adult↗

PubMedDate not supplied

Quantification of formaldehyde induced fluorescence and its application in neurobiology.

The methods used for measurements of fluorescence intensity in histochemical preparation will be described. Under certain conditions, the FIF intensity of biological objects shows a linear relationship with the local monoamine concentration. Microfluorometry enables determination of changes in monoamine concentrations in cell bodies, terminal axons and extraneuronal structures. In certain neuronal systems, FIF intensity of cell bodies appears to be correlated with neuronal activity. FIF intensity measurements of terminal axons can provide information on turnover of monoamine in structures as small as individual varicosities. Finally, the significance of extraneuronal FIF intensity in relationship to neurotransmission will be discussed. This paper aims to show that determinations of FIF provide information on the functional activity of neuronal systems.

Animals↗

PubMedDate not supplied

Effect of intravenous fat on cholecystokinin secretion and gallbladder motility in man.

During total parenteral nutrition (TPN) gallbladder bile stasis and hypomotility have been well documented. Little is known, however, about the effect of the separate components of TPN on gallbladder motor function. Inasmuch as fat, administered intraduodenally, is a potent stimulus of cholecystokinin (CCK) secretion and gallbladder contraction we have investigated whether intravenous (IV) fat affects gallbladder motility. Six healthy volunteers were studied on two separate occasions, during infusion of Intralipid 10%, 200 mL/h or saline infusion (control) for 3 hours, to evaluate the effect of IV infusion of fat on (1) plasma CCK concentration and gallbladder volume and (2) CCK-induced gallbladder emptying. Intravenous infusion of Intralipid resulted in significant increases in serum triglycerides from 0.9 +/- 0.1 to 5.1 +/- 1.3 mmol/L (at 90 min). During fat infusion no significant changes in plasma CCK and gallbladder volume were noted when compared with basal values or to the control experiment. During IV fat, concomitant infusion of 0.25, 0.5, and 1.0 Ivy dog unit (IDU) per kilogram per hour of CCK-33 resulted in a significant reduction in gallbladder volume from 26 +/- 6 cm3 (basal) to 15 +/- 4 cm3 (p less than .05), 6 +/- 2 cm3 (p less than .05) and 2.5 +/- 1 cm3 (p less than .05), respectively. No significant differences in CCK-induced gallbladder emptying were observed between IV fat and saline infusion (control). It is concluded that, in contrast to intraduodenal fat, IV infusion of fat does not affect (1) basal plasma CCK and gallbladder volume and (2) CCK-induced gallbladder contraction.

Adult↗

PubMedDate not supplied

Perfusion analyses in advanced breast carcinoma during hyperthermia.

Blood flow in tumours and healthy tissue determines the ability of obtaining satisfactory temperature distributions in clinical hyperthermia, as well as the success of hyperthermia and radiation treatment. During the hyperthermia treatment, diagnostic data related to tissue blood flow can be determined by analysing the relationship between the amount of power absorbed in the tissue and the resulting temperature rise. The interpretation of the perfusion data (PERF) is highly complicated by the lack of an adequate theory to describe the heat transport in vascularized tissues. In vascularized breast tissues about 10 times as much power is needed to maintain therapeutic temperatures as is necessary in a stationary breast phantom. This large difference in maintenance power levels indicates the extreme importance of blood flow in tissue heat transport. PERF has been determined in 23 patients with advanced breast tumours. In this series (a) perfusion typically did not change during the stationary part of the individual hyperthermic sessions, (b) minimum tumour PERF was not related to tumour volume, and (c) there was no relation between tumour PERF and the ability to heat tumours. PERF can both increase and decrease after successful hyperthermia.

Absorption↗

PubMedDate not supplied

Thermoradiotherapy of primary breast carcinoma.

Since 1981, 40 patients with advanced breast carcinoma have been treated with megavoltage radiotherapy combined with hyperthermia. The irradiation dose to the primary tumour was 50 Gy/25 fractions, five fractions per week. Hyperthermia (aim: 44 degrees C/30 min) was applied once a week, 30 minutes after the midweek radiation fraction. Tumour response did not correlate with the chance of long-term local control. The likelihood of 3-year local control was 46 per cent and 3-year survival was 52 per cent. The local tumour control rate decreased with increasing T stage and was related to non-uniformity of the temperature distribution in the heated volume. It was concluded that (a) the radiation dose should be increased and (b) the temperature uniformity should be improved.

Adult↗

PubMedDate not supplied

Phosphorus NMR study of the response of a murine tumour to hyperthermia as a function of treatment time and temperature.

Evaluating the response of tumours to therapy promises to become one of the major applications of in vivo phosphorus (31P) nuclear magnetic resonance spectroscopy. Decreases in the levels of organic phosphates in favour of inorganic phosphate (Pi) as occur in murine tumours after hyperthermia treatment, can be quantified by the ratio ATP/Pi. In this study the relationship between the time of heating (15, 30 and 60 min) and the temperature (43 and 44 degrees C) was investigated in mice with NU-82 tumours by considering the changes in ATP/Pi ratio as a function of both variables. After 30 min treatment at 43 degrees C the percentage decrease in ATP/Pi ratio was similar to that observed after 15 min at 44 degrees C (42 +/- 9 vs. 48 +/- 9); after 60 min at 43 degrees C the decrease was similar to that after 30 min at 44 degrees C (75 +/- 7 vs. 74 +/- 4). These results give further evidence for the validity of a current working definition of thermal dose: thermal dose = t integral of 0 2T-43 dt. In addition this study shows that in vivo 31P NMR spectroscopy can be a useful means for assessment of thermal dose.

Adenosine Triphosphate↗

PubMedDate not supplied

Treatment of the human retinoblastoma cell line Y-79 growing in the athymic mouse eye with fractionated hyperthermia and/or radiation.

Concentrated cell suspensions of the human retinoblastoma cell line Y-79 were injected into the eyes of athymic nude mice. Three to four weeks after implantation the eyes were treated with fractionated hyperthermia and/or radiation according to various protocols. Radiation was applied with 250 kV X-rays in fractions of 3 Gy, three fractions a week (3 x XT). Hyperthermia was applied once a week for 30 min at 43-45 degrees C (1 x HT). A coaxial microwave applicator (2450 MHz) has been developed for hyperthermia treatment of the mouse eye. The effect of the treatment was evaluated by visual observation of the eyes during a follow-up of several months, and by histopathological examination. No tumour regression was observed after hyperthermia alone (3 x HT). Treatment with 3 x XT or 3 x XT + 1 x HT initially caused tumour regression followed by regrowth in most cases. A treatment protocol of 6 x XT resulted in regrowth in 10 out of 15 eyes. However, after 6 x XT + 2 x HT regrowth was observed in only 3 out of 13 eyes. The difference between these two groups is statistically significant (P less than 0.05). Thus it is concluded that hyperthermia enhances the effect of radiation when the Y-79 cell line is transplanted to the athymic mouse eye, using the fractionation scheme presented here.

Animals↗

PubMedDate not supplied

CT, myelography, and phlebography in the detection of lumbar disk herniation: an analysis of the literature.

Despite the large number of reports on the relative usefulness of various radiographic procedures for the diagnosis of lumbar disk herniation, there has been no consensus of opinion on the best imaging procedure. Different study designs, including criteria for patient selection and retrospective consideration of patients who underwent surgery only, hamper direct comparisons between studies. A major drawback is the common use of "accuracy" as a measure of quality. We reviewed the CT, myelographic, and phlebographic findings in lumbar disk herniation published since 1970. After the reports were systematically classified and assessed for quality, the results became more coherent. Many results tend to be sensitive and not very specific. We found there was no clear difference in the overall diagnostic quality of phlebography, myelography, and CT.

Humans↗