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Biomedical subjects

A Stevenaert

Publications and source records attributed to A Stevenaert.

At least 19 recordsLinked to original sources
PubMed1996

Effects of Schwann cell transplantation in a contusion model of rat spinal cord injury.

Cultured Schwann cells were transplanted at various delays into a spinal cord contusion injury performed at low thoracic level in adult female rats. The Schwann cells were purified from the dorsal root ganglia of adult syngeneic animals. the transplants were well tolerated, and the transplanted Schwann cells invaded the injured spinal cord. As quantified using video image analysis, the survival and growth of the transplanted cells were poor when the grafting procedure was performed 3-4 days after injury and very good when performed immediately or 10 days after injury, in which cases post-traumatic micro- and macrocavitation were strongly reduced. In animals grafted immediately after injury but not in animals grafted after 10 days, post-traumatic astrogliosis was much reduced. The Schwann cells transplanted area was invaded by numerous regenerating axons, the vast majority of which were, based on the neurotransmitter (CGRP and SP) profile, originating from dorsal root ganglion. No regeneration of the corticospinal tract as assessed after anterograde tracing or of descending aminergic fibers could be demonstrated.

Animals↗
PubMed1996

Presurgical Octreotide: treatment in acromegaly.

One hundred seventy-two acromegalics who were operated on using the trans-sphenoidal approach underwent long-term follow-up evaluation. Sixty-four received 100 micrograms octreotide subcutaneously three times daily: for 3 to 6 weeks before surgery in 14 patients (group 1); and for 3 to 9 months in 41 and for 13 to 39 months in nine (n = 50, group 2). In 18 group 2 patients, the dose was increased stepwise to 500 micrograms three times daily because of incomplete suppression of growth hormone (GH)/insulin-like growth factor-1 (IGF-1). Tumor shrinkage was seen in 60% within 3 weeks, being nearly maximal by 3 to 4 months. More group 2 patients had greater than 25% tumor shrinkage (14 of 48 v 1 of 14 in group 1). Clinical response was excellent or good in 89%. Decrease in soft-tissue swelling and weight loss, and improved vitality, performance, carbohydrate metabolism, and cardiovascular function, facilitated anesthetic and surgical management; tumor removal was easy in virtually all cases. In all 64 patients, GH levels decreased by > or = 50%, and to < 2 micrograms/L in three of 14 patients initially and 25 of 50 patients after more prolonged treatment. IGF-1 levels decreased to normal in seven of 14 group 1 and 31 of 50 group 2 patients. Light and electron microscopy showed that adenomatous tissue exposed to octreotide had lysosomal accumulation, amyloid deposition, mild to moderate perivascular fibrosis, and moderate size reduction in both cytoplasmic and nuclear areas, with virtually no cellular complications. Remission with enclosed adenomas was greater (p < .05) than for the 108 patients not treated with octreotide; there was no difference for invasive adenomas. Octreotide use for 3 to 4 months before surgery can be recommended.

Acromegaly↗
PubMed1996

Recurrent ganglion cyst of the peroneal nerve: radiological and operative observations. Case report.

This 34-year-old man presented with right leg pain and foot drop of 1-month duration. The preoperative diagnosis of a 10-cm-long ganglion cyst of the peroneal nerve was achieved using ultrasonography (US), computerized tomography and, particularly magnetic resonance (MR) imaging. Surgical exploration disclosed a lobulated cystic mass filled with gelatinous material, which intermingled with the nerve substance of the deep peroneal nerve. The lesion was completely resected, with the sacrifice of some electrically nonfunctioning fascicles. No connection with the knee joint was found. A good postoperative recovery of motor function was obtained. However, routine postoperative MR imaging disclosed a recurrent ganglion cyst that was slightly less extensive than the original. A careful radiological examination of the knee joint was performed, including arthrography. A communication of the cyst with the tibiofibular joint was clearly demonstrated and was meticulously closed at reoperation. The patient's postoperative course was uneventful, and a third MR image, obtained 5 months after reoperation, showed no sign of cyst recurrence. The patient remained free of symptoms 11 months postoperatively. This case illustrates the value of US and MR in diagnostic imaging. The diagnostic efficacy of US and MR imaging in identifying and characterizing a ganglion cyst is described. Close contact between a ganglion cyst and the tibiofibular joint should raise the possibility of an existing cyst-joint communication and lead to an aggressive radiological workup and/or a surgical search for such a communication.

Adult↗
PubMed1995

The prevalence of colonic polyps in acromegaly: a colonoscopic and pathological study in 103 patients.

Patients with acromegaly are reported to be at risk of developing adenomatous colonic polyps, which are considered to be preneoplastic lesions. This assumption is, however, usually drawn from results obtained in rather small series of patients or without a control group. We, therefore, undertook a prospective colonoscopic and pathological study comprising 103 acromegalic patients and 138 nonacromegalic control subjects referred for irritable bowel syndrome. The prevalence of adenomatous colonic polyps was significantly increased in acromegalic patients compared to that in control subjects (22.3% vs. 8.0%; P = 0.0024). The significance was similarly present in male acromegalic patients (28.6% vs. 5.5% in male control subjects; P = 0.0026), but was absent in female acromegalic patients. The prevalence of colonic polyps was also significantly increased in the group of acromegalic patients under 55 yr of age (20.0% vs. 3.0% in the control group of the same age; P = 0.0026). Other characteristics of adenomatous colonic polyps in acromegaly were the multiplicity and the presence proximal to the splenic flexure. No difference in the duration of acromegaly was found between patients with or without adenomatous polyps. The prevalence of hyperplastic colonic polyps was also significantly increased to 24.3% in acromegalic patients vs 4.4% in control subjects (P < 0.001). In conclusion, in view of the increased incidence of adenomatous colonic polyps, colonoscopy should be part of the follow-up examination in acromegaly.

Acromegaly↗
PubMed1995

Radiation-induced gliosarcoma. Case report and review of the literature.

A 13-year-old boy presented with a cerebral gliosarcoma 12 years after having acute lymphoblastic leukemia treated by chemotherapy and central nervous system prophylaxis treated by radiation therapy (24 Gy) and intrathecal methotrexate. A review of the literature disclosed 129 possible radiation-induced gliomatous and/or sarcomatous brain tumors: namely, 89 gliomas, 36 sarcomas, and four gliosarcomas, including the present case. An analysis of these cases revealed several characteristics that differentiate them from similar spontaneous brain tumors, thus providing arguments for the carcinogenic effect of radiation therapy on intracranial tumors.

Brain Neoplasms↗
PubMed1994

Radiation-induced myelopathy and vertebral necrosis.

Radiation-induced myelopathy is often a diagnosis of exclusion. In addition to the classic criteria needed to support the diagnosis, the presence of another radiation-induced lesion, such as aseptic vertebral necrosis, is useful to confirm the cause of the spinal cord lesion.

Aged↗
PubMed1994

Dramatic improvement of severe dilated cardiomyopathy in an acromegalic patient after treatment with octreotide and trans-sphenoidal surgery.

Severe congestive heart failure developed in an acromegalic patient, and was successfully treated with octreotide followed by trans-sphenoidal surgery. Clinical, hormonal echocardiographic and haemodynamic findings as well as histological heart examination before and after treatment revealed that over-production of growth hormone may induce the myocardial cell degeneration responsible for mechanical heart dysfunction. In addition, this unique example demonstrates the reversibility of myocardial damage following octreotide and trans-sphenoidal surgery, leading to significant improvement in cardiac function with minimal diastolic dysfunction and moderate interstitial fibrosis.

Acromegaly↗
PubMed1994

Variable regions of chromosome 11 loss in different pathological tissues of a patient with the multiple endocrine neoplasia type I syndrome.

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant inherited disorder characterized by nodular proliferation of the parathyroid glands and tumors of the anterior pituitary gland, the endocrine pancreas, and the neuroendocrine cell system of the gut. Loss of the putative tumor suppressor effect of the MEN1 gene is probably responsible for the development of MEN1-associated tumors. We report here a genetic study of a female MEN1 patient with the association of nodular hyperplasia of two parathyroid glands, an insulinoma, multiple duodenal gastrinomas, a prolactinoma, and a gastric carcinoid. We performed loss of heterozygosity (LOH) studies of chromosome 11 on all affected tissues except the insulinoma. Allelic losses of chromosome 11 were detected in several tumors, but the chromosomal regions of LOH were different, suggesting that different somatic mutational events are involved in the pathogenesis of these tumors. LOH of chromosome 11 was also detected in the prolactinoma of this patient, which indicates that the MEN1 gene has a tumor suppressor effect in the pituitary.

Calcium↗
PubMed1994

Autonomously functioning thyroid nodules in a patient with a thyrotropin-secreting pituitary adenoma: possible cause--effect relationship.

A 51-year-old female patient with long-standing hyperthyroidism due to a thyrotropin-secreting pituitary adenoma is reported, who became thyrotoxic again shortly after successful pituitary surgery. Functional testing and scintigraphy suggested the diagnosis of autonomous functioning thyroid nodules, which was confirmed by pathological examination of the resected thyroid tissue. This is the first report revealing the transition from a pituitary-dependent to a thyroid-dependent hyperthyroidism. Autonomous functioning thyroid nodules are, however, considered an intrinsic thyroid defect. In similarity with other disorders, in which trophic hormones may induce an autonomous secretion by the target gland, this report opens the possibility that a humoral factor may play a role in the development of autonomous functioning thyroid nodules.

Adenoma↗
PubMed1993

Soft cervical disc herniation: a retrospective study of 100 cases.

During the period from January 1975 to January 1991, 100 patients with soft cervical disc herniation were operated on by either the anterior (84 patients) or posterior (16 patients) approach. There were 33 women and 67 men, aged from 25 to 67 years (average: 41.5%); 97% presented with radicular symptoms and/or signs while 15% presented with long tract symptoms and/or signs. The patients were evaluated by computed tomography and/or myelography. Thirty-six of the lesions occurred at the C 5/6 level and 54% at the C 6/7 level. Seventy-seven % reported total or partial relief of preoperative symptoms and signs postoperatively. Patients presenting with radiculopathy had better outcome than those presenting with combined radicular and spinal cord involvement.

Adult↗
PubMed1993

Detection of Epstein-Barr virus in a case of undifferentiated nasopharyngeal carcinoma by in situ hybridization with digoxigenin-labelled PCR-generated probes.

A case of nasopharyngeal carcinoma is presented. Epstein-Barr viral genome was identified in the neoplastic cells by in situ hybridization with digoxigenin-labelled polymerase chain reaction-generated probes. We report the development of this technique in paraffin-embedded sections and propose that such identification may prove valuable for the diagnosis of this tumour in routine material.

Adult↗
PubMed1993

Presurgical octreotide treatment in acromegaly.

The effects of octreotide pretreatment before surgery were assessed in 48 acromegalic patients who underwent trans-sphenoidal surgery to remove pituitary adenoma, and compared with 107 patients who did not receive octreotide before surgery. Pretreated patients received octreotide 100 micrograms, thrice daily for 3 to 6 weeks (group 1), or 100 to 500 micrograms, thrice daily for 3 to 39 months (group 2). Total remission of symptoms was seen in 54%. Partial remission of symptoms occurred in 39%. Octreotide pretreatment reduced plasma GH levels by > or = 50% in all patients. GH levels were reduced to < 2 micrograms/1 in 3/14 group 1 cases and 13/34 group 2 cases. Tumour shrinkage occurred in 56.5% of patients. Marked tumour shrinkage (> 25%) occurred in more group 2 patients (10/32 vs 1/14). The tumour was soft in 39 patients, firm in 6 and hard in 3 cases. Soft consistency aided surgical removal of adenomas. Remission was greater in enclosed adenomas than in invasive tumours in both octreotide pretreated and nonpretreated acromegalics (76 vs 30%). Remission was more likely if the adenoma was less than 16 mm. Remission rate was significantly greater (p < 0.05) in all octreotide pretreated than in untreated patients for enclosed adenoma, but not for invasive adenoma. Octretide pretreatment can be recommended for three to four months prior to surgery.

Acromegaly↗
PubMed1992

Experimental acute traumatic injury of the adult rat spinal cord by a subdural inflatable balloon: methodology, behavioral analysis, and histopathology.

We describe an experimental model to produce closed traumatic injuries to the spinal cord of adult rats. This model uses an inflatable balloon that is introduced in the dorsal subdural space and moved to a location rostral to the laminectomy site. The spinal cord trauma can be graded by varying either the duration of compression or the volume of saline used to inflate the balloon. The locomotor deficit of animals with various degrees of injury has been assessed at increasing delays after trauma. The parameters generating transient or definitive deficits of varying intensity were defined. Some injured animals underwent nuclear magnetic resonance imaging. Detailed histopathological studies demonstrated that the extent of the spinal lesion was significantly correlated with the physical parameters of compression and with the severity of the behavioral deficit.

Animals↗
PubMed1992

Contrast behavior between microadenoma and normal pituitary gland after gadolinium injection as a function of time at 1.5 T.

The behavior of contrast enhancement between a microadenoma and the normal pituitary gland after gadolinium injection was evaluated in 12 operatively confirmed cases using a repetitive sequence of four coronal T1-weighted spin echo series (T1 SE) (continuous acquisition, TR = 400 ms), followed by conventional coronal T1 SE (TR = 600 ms) and a three-dimensional fast low-angle shot sequence. The first and second acquisitions were useful with respect to delayed scans only in 3 cases (25%). Nevertheless, in these cases confident diagnosis could also be made on pre-contrast studies, which diminishes the real advantage of this finding. For a 1.5 T MRI unit we advocate starting with coronal T1 SE 30 s after a rapid injection of gadolinium.

Adenoma↗
PubMed1992

Presurgical octreotide treatment in acromegaly.

The aim of this study was to determine the role of octreotide administration in acromegalic patients as a preparation for selective adenomectomy using transsphenoidal route. Octreotide was administered for 3 to 6 weeks before surgery in 12 patients and for 4 to 39 months in 25 patients. The clinical response was judged as excellent or good in 10 of 12 patients from group I and in 23 of 25 patients from group II. Marked reduction (ie, greater than 50% of initial values) in serum growth hormone (GH) levels was seen in all patients, with levels to less than 5 micrograms/L in 68% of patients and less than 2 micrograms/L in 27%. Insulin-like growth factor 1 (IGF-1) levels decreased to within normal limits in half the cases. During long-term treatment, an escape phenomenon could be seen. Varying degrees of tumor shrinkage were seen in more than 50% of cases. During surgery, with regard to the relative ease or difficulty in removing the tumor, the consistency of the tumor and the separation of normal from pathological tissue, no significant difference was observed between patients given octreotide and those from control series. Morphological changes in adenomatous tissue were rather small. The surgical outcome was similar in the pretreated series as in the control series, except in enclosed adenomas, which showed a tendency to a higher success rate. Since octreotide improves both the clinical condition and hormonal parameters and induces varying degrees of tumor shrinkage, it is potentially useful as an adjunct to surgery. Morphological data suggest that octreotide exercises a functional inhibitory effect on GH release.

Acromegaly↗
PubMed1992

Treatment of macroprolactinomas with the long-acting and repeatable form of bromocriptine: a report on 29 cases.

Twenty-nine patients with macroprolactinomas were treated by monthly intramuscular injections of the long-acting and repeatable form of bromocriptine (Parlodel-LAR) in doses ranging from 50-150 mg. They were divided into two groups: group I consisted of 22 patients who received Parlodel LAR before transsphenoidal adenomectomy; group II was composed of 7 patients with earlier neurosurgery and of 2 patients from group I not cured by transsphenoidal adenomectomy. Duration of therapy varied from 1-12 months, and a total of 104 injections was given. At nadir day, serum PRL levels were situated between less than 1% and 43% of pretreatment values. At day 28 after the first injection, serum PRL levels varied between less than 1% to 139% of initial values. No difference could be detected between the two groups regarding the percent of PRL inhibition. Long-term treatment with Parlodel-LAR resulted in a sustained inhibition of PRL secretion, except for 1 case. Resumption of menstrual cycles occurred in 4 out of 15 women and correction of hypogonadism in 4 out of 14 men. Amelioration of disturbed visual fields was recorded in 3 out of 8 patients. Diminution of the adenoma volume was radiologically documented in 14 out of 22 cases. Only few and mild side effects were recorded. One patient with partial adrenal deficiency suffered from a syncope, but this was prevented by hydrocortisone supplementation during the subsequent Parlodel-LAR administration. In conclusion, Parlodel-LAR proved effective in the treatment of macroprolactinomas, achieving rapid inhibition of PRL secretion, and in some patients amelioration of hypopituitarism, reduction in tumor size, and improvement in visual fields, and caused no serious side effects. It is a valuable preparation to surgery and can also be used in long-term medical therapy.

Adult↗