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Biomedical subjects

J Schipper

Publications and source records attributed to J Schipper.

At least 73 records · Page 4Linked to original sources
PubMed2000

Indications for computer-assisted treatment of cranio-maxillofacial tumors.

OBJECTIVE: Ablative tumor surgery requires detailed planning using computed tomography (CT) or magnetic resonance imaging (MRI). Reconstruction following tumor resection is dependent on reliable information for choosing the correct type and volume of grafts and predicting the outcome. This study evaluates the benefit of and the indications for computer-assisted surgery in the treatment of cranio-maxillofacial tumors. MATERIALS AND METHODS: Based on a CT or MRI data set, the STN Navigation System (Stryker-Leibinger) was used for preoperative planning, intraoperative navigation, and postoperative control of radical tumor resection and primary and secondary reconstruction. Tumor resection was preoperatively planned and intraoperatively navigated. Preoperatively, the required soft and hard tissue were measured using the mirrored data set of the unaffected side of the facial skeleton; the size and location of the graft were chosen virtually. Intraoperatively, contours of transplanted tissues were navigated in accordance with the preoperatively simulated reconstructive result. RESULTS: Computer-assisted treatment was successfully completed in all cases of radical tumor resection, and safety margins outlined preoperatively could be precisely controlled during tumor resection. Reconstruction was designed and performed exactly as virtually planned. CONCLUSIONS: Image-guided treatment improves preoperative planning by visualization of the individual anatomy and the intended reconstructive outcome, and by objectivation of the effect of adjuvant chemo-/radiotherapy. Intraoperative navigation makes radical tumor surgery more reliable by showing the determined safety margins, preserving vital structures, and guiding reconstruction to preplanned objectives.

Adolescent↗
PubMed1999

[Objective auditory brainstem response threshold deficits in patients with cerebellopontine angle tumors].

The established criteria of auditory brainstem responses (ABR) such as JV latency, JI-V interpeak latency and interaural differences of latency or amplitude have been found to be sensitive for detecting tumors of the cerebellopontine angle if a response is present. However, the ABR can be absent in cases of acoustic neuromas because of desynchronization, even though pure-one audiometry indicates that responses should be present. This retrospective study compared the ABR and pure-tone thresholds in 234 cases with cerebellopontine angle tumors and a control group of 181 cases with sensory hearing losses in order to quantify threshold discrepancies. The average deficit of the objective ABR threshold (DOABRT) to the subjective pure-tone threshold for those frequencies between 1-6 kHz was 3.6 dB for the control group (ABR and pure tone thresholds very close) and 31.2 dB for the tumor group (ABR threshold much higher than the pure-tone threshold). ABR thresholds 30 dB higher than the high-frequency pure tone thresholds were found in 40.6% of the tumor group and in none of the control group. Thus, deficits of the ABR threshold >30 dB can be considered to be an additional criterion for detecting retrocochlear disease and increases ABR sensitivity for tumor detection even if responses are absent.

Adolescent↗
PubMed1999

Endoscopic ultrasound-guided brachytherapy of head and neck tumours. A new procedure for controlled application.

Brachytherapy is an established procedure in primary and in recurrent cancer. We perform afterloading brachytherapy during general anaesthesia. The target organ is punctured with hollow needles which are loaded with 192iridium via remote control. The depth and number of needles depend on tumour extension. In the interdisciplinary approach of our departments, this method has been improved and supplied by B-scan ultrasound control. Needles are positioned under continuous ultrasonographic guidance, and adjacent structures (e.g. the carotid artery) are localized ultrasonographically. Thus violation of the large vessels is avoided and the exact position of the needles within the tumour is improved. In this paper, we report results on 22 patients suffering from recurrent carcinoma of the head and neck following surgery and curative radiation, and 17 patients with first onset of cancer. We did not observe any severe complications such as haemorrhage, osteomyelitis, or dyspnoea. The only side-effect was temporary oedema, sometimes associated with a short-term increase of pain. No systemic side-effects occurred. The method is described and results from both patient groups are reported in detail. We conclude from our data that ultrasonographically-controlled endoscopic brachytherapy is a valuable procedure in locally-advanced primary, and in recurrent head and neck cancer.

Aged↗
PubMed1999

[Value of B-image ultrasound in patients with carcinomas of the upper aerodigestive tract and N0 lymph node stage].

BACKGROUND: The wait-and-see policy in patients with a N0 neck stage is not common. PATIENTS AND METHOD: One hundred twenty-one patients with a pT1 or pT2 carcinoma of the upper aerodigestive tract and a N0 neck stage in ultrasound studies underwent transoral laser microsurgery without neck dissection or radiation therapy. In these patients the probability of survival and local or regionals recurrence were analyzed in a follow-up period of 18 to 36 months. RESULTS: Thirty patients in whom cervical lymph nodes were detected in ultrasound studies, underwent a curative neck dissection procedure. In 8 of these 30 patients, lymph node metastases were histologically demonstrated, and 6 patients showed a local recurrence. The probability of survival was 1.0 and the probability of being free of local or regional recurrence was between 0.95 and 0.6 depending on the tumor location. CONCLUSIONS: A wait-and-see policy will not necessarily alter the prognosis, which depends on the location of the tumor. Ultrasound follow-up studies should be performed at regular intervals.

Adult↗
PubMed1998

[Hyperfractionated accelerated simultaneous radiochemotherapy in advanced hypopharyngeal carcinomas. Survival rate, retained function quality of life in a phase II study].

Forty-one patients with locally advanced hypopharyngeal carcinomas were followed for at least 3 years (median, 60 months) after simultaneous radiochemotherapy. Conventionally fractionated radiotherapy was administered as 5 x 2 Gy/week to a total dose of 30 Gy within 3 weeks. From the fourth week an accelerated hyperfractionated schedule was used as 2 x 1.4 Gy/day five days weekly given exclusively to the first order target volume of macroscopic tumor (adding up to a total dose of 72 Gy in six weeks). The second and third order target volumes received conventional fractionation only to 60 Gy and 50 Gy, respectively. The moderate acceleration of the concomitant boost scheme in the second half was counterbalanced during the first week by the introduction of a 5-fluorouracil bolus of 350 mg/M2 with 200 mg/M2 folinic acid and a subsequent continuous infusion using the same dose each 24 h for 5 days. Additionally, a Mitomycin-C bolus of 10 mg/M2 was infused at the fifth day and on the first day of the sixth week. Six weeks after treatment the patients were restaged. In cases with residual carcinoma salvage surgery was performed (11 patients). Late effects of therapy were analyzed according to the Lent-Soma index and life quality according to the European Organisation for Research and Treatment of Cancer-Module. Late effects of treatment were tolerable and were controlled locally. The 3-year-survival rate was 39%, with a local-regional recurrence-free control rate of 71%. Fifty-two percent of all cases of death were caused by distant metastases, secondary carcinomas or other diseases not related to tumor recurrence. The poor prognosis of hypopharyngeal carcinomas despite acceptable local tumor control may be due to specific biological factors present in affected patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Second primary tumours in hereditary- and nonhereditary retinoblastoma patients treated with megavoltage external beam irradiation.

The purpose of this retrospective study is to investigate the influence of 45 Gy megavoltage external beam radiotherapy on the occurrence of second primary tumours in hereditary- and non-hereditary retinoblastoma patients. Eighty-seven hereditary and 19 non-hereditary patients were irradiated for retinoblastoma. The follow-up of the hereditary patients ranged from 4-23 years (mean 12.4 years), of the non-hereditary patients from 6-23 years (mean 12 years). In the hereditary group 4 patients developed a second primary tumour (2 rhabdomyosarcoma, 1 osteosarcoma, 1 malignant histiocytoma), and 5 patients developed a pineoblastoma. Three second primary tumours were situated inside the radiation field. The latency period ranged from 1.5 to 18 years (mean 4.8 years). None of the non-hereditary patients developed a second primary tumour. The actuarially calculated probability of being free from second primary tumours was 96.9% at 10 years and 89.4% at 20 years (pineoblastoma excluded). The survival was 91.2% at 10 years and 84.2% at 20 years (pineoblastoma excluded). From this study it is suggested that external beam irradiation has a potentiating effect in patients, with the genetic predispopsition for retinoblastoma and who are more susceptible to second primary malignancies.

Adolescent↗
PubMed1997

Gallbladder motility in response to sham feeding and cholecystokinin in lean and obese subjects.

The risk of developing gallstones is increased in obese subjects. We have investigated whether gallbladder motility in obese subjects is different from that in lean control subjects. In 25 healthy non-diabetic obese subjects and 20 age- and sex-matched lean controls, fasting gallbladder volumes, gallbladder contraction in response to cephalic vagal cholinergic stimulation by modified sham feeding (MSF) and to hormonal stimulation with cholecystokinin (CCK) were studied. Gallbladder volumes were measured during a 30-min MSF period followed 1 h later by a 1-hour continuous i.v. infusion of 0.5 IDU/kg ideal weight of CCK-33. Fasting gallbladder volumes were significantly (p < 0.001) larger in obese (47 +/- 4 cm3) compared to lean subjects (24 +/- 2 cm3). Fasting gallbladder volume was correlated with body mass index (p < 0.01). Gallbladder contraction during MSF was significantly (p < 0.01) reduced in obese (12 +/- 2%) compared to lean subjects (22 +/- 3%). CCK infusion, leading to physiological post-prandial plasma CCK levels, induced a significantly (p < 0.001) greater absolute gallbladder contraction in obese (27 +/- 3 cm3) compared to lean subjects (15 +/- 1 cm3) but the percentage gallbladder contraction was in the same range (64 +/- 3% vs. 67 +/- 4%, respectively). In addition, residual gallbladder volumes after CCK infusion were significantly (p < 0.001) larger in obese (15 +/- 2 cm3) than in lean subjects (7 +/- 1 cm3). Two groups of obese subjects were identified: one with increased (>40 cm3) and one with normal (< or = 40 cm3) fasting gallbladder volumes. Only obese subjects with increased fasting volumes showed abnormal gallbladder motility.

Adult↗
PubMed1996

Quantification of orbital and mid-facial growth retardation after megavoltage external beam irradiation in children with retinoblastoma.

PURPOSE: The late side effects of external beam irradiation in patients with retinoblastoma such as orbital bony growth retardation, are a serious problem in adolescence. Therefore, a quantitative study was performed to investigate the late effects of irradiation on orbital growth in patients with retinoblastoma. METHODS: The orbits of 68 patients with retinoblastoma, 52 bilateral and 16 unilateral, were divided into two treatment groups: radiotherapy alone, 77 orbits; and radiotherapy + enucleation, 43 orbits. Follow-up time was 12 to 240 months (mean, 95 months) in group 1 and 27 to 216 months (mean, 97 months) in group 2. These groups were subdivided further into age groups at which radiotherapy was given. The morphometric measurements of these groups were compared. RESULTS: The authors showed that irradiation causes a significant growth retardation when compared with the growth of nonirradiated orbits (P<0.001). They also demonstrated that radiotherapy in children younger than 6 months of age is more damaging to the orbital growth than at an older age (P<0.01). Finally, the authors showed that secondary enucleation does not have an additive growth-retarding effect. CONCLUSION: Orbital growth retardation in patients with retinoblastoma after radiotherapy is influenced mainly by the age at which irradiation is given and is defined at 6 months. Theoretically, it would be desirable to postpone irradiation in children until they are older than 6 months of age if possible. The irradiation effect on these orbits is not enhanced by enucleation.

Bone Development↗
PubMed1995

Atlantoodontoid osteoarthritis: comparison of lateral cervical projection and CT.

The purpose of this study was to assess the accuracy of lateral cervical spine radiography in the detection of degenerative atlantoodontoid (AO) osteoarthritis, with CT as gold standard. In 50 patients, lateral radiographs and CT of the AO joint were blindly and independently graded by two radiologists: 0 = normal, 1 = mild degenerative disease, 2 = severe degenerative disease. Radiography was most accurate in distinguishing absent or mild disease from severe disease (83% sensitivity, 84% specificity). Sensitivity in distinguishing absent disease from mild or severe disease was 87%. Specificity, however, was low (52%), due to overestimation of the degenerative involvement on radiography. It is concluded that conventional radiography is a useful technique in screening for AO osteoarthritis, especially in severely degenerated joints. However, CT provides the best radiographic detail necessary for accurate diagnosis.

Adult↗
PubMed1995

Erroneous diagnosis of distal intestinal obstruction syndrome in cystic fibrosis: clinical impact of abdominal ultrasonography.

OBJECTIVE: To describe the use of abdominal ultrasonography in the differential diagnosis of distal intestinal obstruction syndrome (DIOS). DESIGN: Four case reports. SETTING: Adult cystic fibrosis centre (140 patients). PATIENTS: Four cystic fibrosis patients presenting over 18 months with clinical symptoms suggestive of a DIOS which could not be substantiated. OUTCOME: In all cases abdominal ultrasound was valuable in making a diagnosis. CONCLUSION: Abdominal ultrasound is a useful diagnostic tool for differentiating a DIOS from other abdominal conditions.

Adolescent↗
PubMed1994

Inverse relation of E-cadherin and autocrine motility factor receptor expression as a prognostic factor in patients with bladder carcinomas.

Down-regulation of E-cadherin, an intercellular adhesion molecule, and up-regulation of autocrine motility factor receptor (gp78) expressions have been shown to play a role in tumor cell invasion and metastasis. Monoclonal antibodies against E-cadherin and gp78 were used to stain serial snap-frozen sections of 12 normal bladder and 83 bladder carcinoma specimens (27 noninvasive, 53 invasive, and 3 metastases). In normal urothelium, E-cadherin is expressed while gp78 is not. Positive expression of E-cadherin and negative expression of gp78 were found to be associated with a low risk of clinical progression in the superficial bladder carcinoma patient group. While reduction in E-cadherin concomitantly with an increase in gp78 expression was associated with poor prognosis, 71% of the patients (n = 30) underwent rapid cancer progression, and 32% of the patients died of cancer-related disease at a median of 2 years after initial diagnosis. Thus, it is suggested that reduction of E-cadherin expression associated with an increase in the level of gp78 in bladder cancers may define a high risk group of patients. The dual use of these two antigens may improve early diagnosis of high risk bladder cancer patients and influence treatment decisions.

Aged↗
PubMed1994

Effect of hyperglycaemia on gallbladder motility in type 1 (insulin-dependent) diabetes mellitus.

Patients with diabetes mellitus are at increased risk of developing gallstones. This has been attributed, among other factors, to alterations in gallbladder motility in the presence of autonomic neuropathy. Since high blood glucose concentrations impair gastric emptying in diabetic patients, we have investigated the effect of acute hyperglycaemia on gallbladder motility. Seven Type 1 (insulin-dependent) diabetic patients were studied twice during euglycaemia (blood glucose 5 mmol/l) and hyperglycaemia (blood glucose 15 mmol/l) using a clamp technique. In addition, seven healthy volunteers were studied during euglycaemia and hyperglycaemia. Gallbladder volumes, measured with ultrasonography, were studied before and during infusion of step-wise increasing doses of cholecystokinin-33, 0.25, 0.5 and 1.0 Ivy Dog Unit.kg-1.h-1, each dose for 30 min. Mean basal gallbladder volumes were not significantly different in the four experiments. Administration of cholecystokinin resulted in significant (p < 0.05) dose-dependent reductions in gallbladder volume in all experiments. During euglycaemia the gallbladder contraction in diabetic patients was not significantly different from the control subjects. During hyperglycaemia the gallbladder contraction in the diabetic patients was significantly (p < 0.05) reduced compared to euglycaemia only during infusion of 0.25 Ivy Dog Unit.kg-1.h-1 of cholecystokinin (19 +/- 6% vs 33 +/- 6%). Compared to euglycaemia, during hyperglycaemia the gallbladder contraction in the control subjects was significantly (p < 0.05) reduced during infusion of 0.25, 0.5 and 1.0 Ivy Dog Unit.kg-1.h-1 of cholecystokinin (14 +/- 4% vs 31 +/- 3%; 42 +/- 6% vs 65 +/- 5%; 74 +/- 4% vs 90 +/- 3%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Changes in tumor perfusion induced by chemotherapy in bone sarcomas: color Doppler flow imaging compared with contrast-enhanced MR imaging and three-phase bone scintigraphy.

PURPOSE: To prospectively evaluate color Doppler flow imaging (CDFI) with spectral analysis versus dynamic gadolinium-enhanced magnetic resonance (MR) imaging and three-phase bone scintigraphy in monitoring the effect of chemotherapy on bone sarcomas. MATERIALS AND METHODS: Seventeen osteosarcomas and five Ewing sarcomas were examined with these imaging techniques before and after chemotherapy. Results were compared with the histopathologic response. RESULTS: Before chemotherapy, high systolic Doppler frequency shifts (DFSs) and/or low-impedance Doppler signals were found in all but one tumor. Resistive indexes (RIs) in tumor-feeding arteries were substantially lower than in contralateral normal arteries. After chemotherapy, DFSs disappeared in five of seven good respondents and remained substantial in all but one poor respondent. RIs increased substantially in all good respondents and decreased or showed minor changes only in all but one poor respondent. CONCLUSION: CDFI with spectral analysis has an advantage over the other two techniques in monitoring the efficacy of chemotherapy in bone sarcomas because of its superior accuracy, noninvasive nature, availability, and low cost.

Adult↗
PubMed1994

Relation of intracorporal pressure and end-diastolic velocity during duplex Doppler sonography in the evaluation of veno-occlusive dysfunction.

In 37 patients 25 to 69 years old (mean age 49.6 years) with suspected 'vasculogenic erectile dysfunction', diagnosed on the basis of repeated negative reactions to intracavernous pharmacological stimulation, duplex Doppler measurements and pharmacocavernosometry were performed in one session under simultaneous pressure registration. A statistically significant difference between patients with and without veno-occlusive dysfunction was found by combining end-diastolic velocity and pressure in time. We conclude that color Doppler scanning in combination with simultaneous pressure registration can predict veno-occlusive dysfunction in 83-95% of the patients.

Adult↗
PubMed1993

A new approach to the immunocytochemistry of cAMP. Initial characterization of antibodies against acrolein-fixed cAMP.

A method is described to couple cyclic adenosine 3',5' monophosphate (cAMP) to a carrier protein by means of acrolein. Antibodies against this conjugate were raised in mice. These antibodies proved to be highly specific for acrolein-fixed cAMP in a gelatin model system. Slices (300 microns in thickness) from rat cerebral cortex were incubated in vitro and the dopaminergic control of adenylate cyclase activity was drug-manipulated. This manipulation was visualized by application of the cAMP-antisera on cryostat sections of the acrolein fixed slices.

Acrolein↗
PubMed1993

The contribution of colour Doppler flow imaging to the study of cerebral haemodynamics in the neonate.

We investigated the contribution of colour Doppler flow imaging (CDFI) to duplex-ultrasonography of the neonatal brain. In pre- and full-term infants, CDFI facilitated spectral analysis of blood flow velocity wave forms in most major intracranial arteries, enabling blood flow velocity measurements. Moreover CDFI depicted major deep and superficial veins, enabling venous blood flow velocity measurements. Smaller arteries could also be imaged in a substantial number of infants in regions with haemorrhagic or ischaemic lesions. The method may also offer the opportunity to assess regional cerebral blood flow in the neonatal brain, although further study is necessary to determine whether accurate, reproducible flow velocity measurements are possible in these vessels.

Blood Flow Velocity↗