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Biomedical subjects

H Dietz

Publications and source records attributed to H Dietz.

At least 55 records · Page 3Linked to original sources
PubMed1992

[Initial experiences with a new cerebrospinal fluid collection system].

Due to clinical requirements and to improve the handling of CSF drainage set we developed a new concept, consisting of an arrangement of constructions, which are already available. Besides other advantages, the set provides an ICP monitoring, a pump device and a protection of the air filter of the collecting tank for safer transport. Opening the system for the performance of diagnostic or therapeutic manoeuvres can therefore be avoided. This new equipment has been tested in 28 patients having a ventricular or lumbar CSF drainage with good results and has been quickly accepted by the medical staff. The construction is described in detail.

Adolescent↗
PubMed1992

Subacute hydrocephalus after experimental subarachnoid hemorrhage: its prevention by intrathecal fibrinolysis with recombinant tissue plasminogen activator.

It is investigated whether intrathecal fibrinolysis may prevent subacute hydrocephalus after subarachnoid hemorrhage (SAH). In 19 cats, SAH was induced by the intracisternal infusion of 1 ml/kg body weight of fresh autologous blood at a rate of 0.6 ml/min. Eleven of those animals were treated by intrathecal fibrinolysis performed 24 hours after experimental SAH by intracisternal infusion of 3 mg of recombinant tissue plasminogen activator. Included were eight animals suffering from experimental SAH and four healthy animals retained for control. A computed tomographic scan performed 24 hours after the SAH displayed an acute hydrocephalus from the experimental procedure. Cerebrospinal fluid outflow resistance was 71 +/- 5.0 mm Hg/ml/min in the healthy animals, 265 +/- 19.8 mm Hg/ml/min in the nontreated animals 7 days after SAH, and 151 +/- 6.4 mm Hg/ml/min in the recombinant tissue plasminogen activator-treated animals 7 days after SAH (mean +/- standard deviation; changes significant with P less than 0.01). Postmortem planimetry of both lateral ventricles gives a mean of 3.7 +/- 2.7 mm2 in the healthy animals, 11.1 +/- 3.9 mm2 in the nontreated group after SAH (P less than 0.01), and 3.5 +/- 1.1 mm2 in the animals treated with recombinant tissue plasminogen activator. Intracranial pressure monitoring demonstrated marked intracranial pressure waves only in the nontreated animals after SAH. It is concluded that intrathecal fibrinolysis may prevent subacute hydrocephalus after experimental SAH.

Animals↗
PubMed1992

[Multiple meningiomas in different compartments of the cerebrospinal axis].

Multiple meningeomas in the absence of Recklinghausen's disease are rare and usually occur in a single compartment of the neuroaxis. Multiple meningeomas in different neuroaxial compartments are an even rarer condition, only a few cases having been reported. We describe four cases, each with two meningeomas in different compartments of the neuroaxis. Their peculiarity consists in the fact that the different tumours developed at different times and locations in the supratentorial and spinal regions. The radiological and operative findings are described. The possibility of dissemination via the cerebrospinal fluid or blood or of a multifocal origin or genetic predisposition is discussed.

Adult↗
PubMed1991

Influence of type and extent of surgery on early results and survival time in glioblastoma multiforme.

We studied the influence of the type of surgery (microsurgery or macrosurgery) and extent (complete resection with lobectomy, complete resection alone, partial resection with lobectomy or partial resection alone) on early postoperative results and survival time in 118 consecutive patients who underwent surgery for glioblastoma multiforme. Early results were assessed by the Karnofsky score at 4 weeks postoperatively. Survival was compared using Kaplan-Meier curves and Mantel statistics. The median survival time (MST) after microsurgery (12.1 months) was significantly longer than that after macrosurgery (7.3 months). The longer survival after microsurgery was, however, largely attributable to better early results and a consequently higher proportion of patients who could undergo radiotherapy. Complete resection was superior to partial resection. Additional lobectomy did not appreciably influence the early results and the MST in completely resected tumours. So the MST after complete resection in the microsurgical group without lobectomy was 12.6 months, with lobectomy 12.9 months. In the macrosurgical group the respective values were 7.4 months without and 8.2 months with lobectomy. In incompletely resected tumours lobectomy worsened the early results compared to incomplete resection alone and led to a shorter MST.

Brain Neoplasms↗
PubMed1991

Ultrastructural changes in the blood-brain barrier after nimodipine treatment and induced hypertension.

Fourty-four narcotized rats were split into two equal groups, one being treated with nimodipine and the other with a placebo. By use of norfenefrine the blood pressure was raised to values of 150 and 180 mm Hg within the limits of the autoregulation of brain perfusion and under continuous measurement. Fifteen minutes after application of the standard tracer, horseradish peroxidase, the animals were exsanguinated using a saline perfusion and then perfusion-fixed with Karnovsky's solution. After development of the peroxidase staining the brain sections were evaluated and then allocated to their respective groups. In brain tissues from the experimental group significantly more frequent perivascular accumulations of horseradish peroxidase reaction product were found (P less than 0.001). In electron micrographs it could be seen that the tight junctions were intact and that there was a neuroendothelial transport, with horseradish peroxidase-filled vesicles, in the endothelium, muscle cells, and brain parenchyma. These vesicles represent a medium of transport for all proteins of high molecular weight and can therefore result in brain edema. It is concluded that nimodipine damages the blood-brain barrier by disturbance of the autoregulation of the cerebral blood flow.

Animals↗
PubMed1991

Effects of 33% stable xenon/O2 mixture on somatosensory evoked potentials.

The influences of 30% stable xenon/O2 mixture on somatosensory evoked potentials were investigated in 8 patients with and without Diamox application. Changes of the amplitude of the primary cortical response occurred frequently and correlated well with the psychotropical effect of xenon. They usually normalized within 2 to 3 minutes after ending xenon inhalation. There were no significant changes of the latency of the N20.

Drug Stability↗
PubMed1990

[Initial results of the long-term effect of PUVA therapy in lichen ruber of the mouth].

In a study involving 77 patients affected by lichen ruber lenticularis oralis, the relative clinical long-term healing rate was determined after application of a "Systemic Mouthmucosal Photochemotherapy" (SMPT). The results obtained showed that 78.5 percent of the patients were cured while the disease recurred in 21.5 percent of the patients. Against of 12 patients with erosive Lichen ruber oralis have had 9 patients an recidive post Re-SMPT.

Follow-Up Studies↗
PubMed1989

Combined orbito-frontal injuries.

Our experiences in 55 patients suffering from orbitofrontal injuries are discussed. The prognosis is determined by the severity of the brain injuries and the cerebral complications. The relation of fronto-basal, orbital, and maxillofacial fractures to lesions of the brain tissue and contents of the orbita is best demonstrated in high-resolution CT scan. Surgery is usually possible in one interdisciplinary operating session. Penetrating injuries with CSF leakage primarily require operative therapy; indirect, open, frontobasal fractures should be covered secondarily within two weeks following trauma. A debridement of the paranasal sinuses is necessary if drainage is obstructed or infection is imminent. We found no improvement of visual function in eight patients following transethmoidal optic nerve decompression; the visus recovered only in one patient after removal of a bone fragment impressing on the eyeball. Typical complications are systematic or central nervous system infections; less frequent are traumatic cavernous-sinus fistulas and pneumato- or encephaloceles.

Adult↗
PubMed1989

Chronic cerebrovascular insufficiency on the xenon CT scan.

Several investigators have described CT-negative low flow areas in TIA and stroke patients in the chronic phase. The emission tomographic SPECT image they employed has, in contrast to the xenon CT method, no direct relation to the x-ray transmission CT scan. The aim of our study was to study the phenomenon of CT-negative low flow areas using the xenon CT method, a method especially well suited for such cases. 57 xenon CT examinations were performed in 40 TIA patients. Flow data from brain tissue which appeared to be anatomically intact in a slice 5 cm above the canthomeatal plane were analyzed. In the TIA group, the flow in the gray matter was found to be significantly lower on the clinically affected side: symptomatic side, 61.8 +/- 14.7 ml/100 g/min; asymptomatic side, 66.4 +/- 15.8 ml/100 g/min (p less than 0.001). In the stroke group, the flow in the white matter was also affected; symptomatic side, 31.2 +/- 9.8 ml/100, g/min; asymptomatic side, 35.3 +/- 11.1 ml/100 g/min (p less than 0.01). Gray matter: symptomatic side, 56.1 +/- 11.4 ml/100 g/min; asymptomatic side, 66.0 +/- 11.0 ml/100 g/min (p less than 0.001). The findings indicate that the appearance of CT-negative low flow areas in TIA and stroke patients during the chronic phase is the rule rather than the exception. Flow adaptation to anatomic changes not discernible by CT can be differentiated from clinically relevant flow impairment only by testing the cerebrovascular reserve.

Aged↗
PubMed1989

[Ultra-high, short-term dexamethasone therapy in craniocerebral trauma. Rationale and design of a multicenter study].

In spite of 20 years of discussion the value of corticosteroids in the therapy of head injury still remains controversial. Most animal experiments show an improvement of edema parameters with dexamethasone given immediately after trauma; pharmacological data suggest a further increased "ultrahigh" dosage compared to so-called "high" doses up to now. Simultaneously, the treatment duration might be reduced to 48-72 h after injury. The clinical studies available are not satisfying due to low numbers of patients, insufficient trauma classification and restriction to most severe brain injuries, and do not allow a definite answer. Little side effects and risks, however, were found with clinical steroid trials so far. We therefore perform a new multicenter trial with dexamethasone after head injury, whose design is presented: A sufficient number of patients (n greater than = 240) is recruited according to a priori defined criteria for statistical evaluation. Treatment starts with ultrahigh dosage of 500 mg dexamethasone (Fortecortin) initially not later than 3 h after injury, the treatment duration is limited to 51 h. The selection of patients is based on restrictive criteria of inclusion and exclusion, the age of patients ranges from 15 to 55 years. For maximal statistical separation and for reduction of disturbing factors the representativity of trauma patients is intentionally neglected.

Adolescent↗
PubMed1989

Cavernous angiomas of the supratentorial compartment.

In a retrospective study the clinical data of ten consecutive patients with a cavernous angioma (cavernoma) confined to the supratentorial compartment are presented. The lesions were almost equally distributed among the cerebral cortex with three cavernomas each in the parietal and temporal region and two lesions each being located in the frontal and occipital lobes. The predominant clinical symptoms were either focal or generalized seizures which occurred in 8 patients. One patient became symptomatic due to an intracerebral bleeding from the cavernous angioma, one patient developed a visual field defect from an occipitally localized cavernoma. In 7 patients the neurological status on admission was normal, two patients had signs of a slowly progressing psychosyndroma, one patient had a homonymous hemianopia. The time interval from onset of symptoms to final diagnosis showed a considerable variability ranging from one months to 33 years. Only in half of the patients this interval was less than 6 months. CT-scan was the most important radiological procedure for the diagnosis of these malformations, while MRI may be even more sensible in detecting these lesions in the future. The treatment of choice for these tumorous vascular malformations is microneurosurgical extirpation. This can be accomplished with neglectible morbidity leading to a significant decrease of the preoperative incidence and severity of epileptic seizures.

Adolescent↗
PubMed1988

Clinical and neuropsychological results after operative and conservative treatment of arachnoidal cysts of the perisylvian region.

Most supratentorial arachnoid cysts are found in the perisylvian region. They are thin extracerebral fluid filled pouches and occasionally symptoms are caused by space occupation. We have studied 28 cases with these cysts, with follow-up time varying from one to ten years. 8 of the cases presented with a sudden onset of seizures, while 5 cases had a history of seizures dating from childhood. 14 cases underwent surgery, of whom most had histological evidence of previous haemorrhage and some had evidence of subdural haematoma. Surgery was uneventful in all cases regardless of the method used and all had satisfactory outcome. All 28 cases were followed up systematically including intelligence testing and specific testing of memory and other temporal lobe functions. The group scored normal in standardized tests with a distribution similar to the normal population. Results did not show any deficit of function related to the localization of the cyst. Despite of the severity of their initial symptoms, postoperative cases performed just as well at psychological testing. Those cases who continued to experience seizures showed a memory disturbance and seemed to lack initiative. Most cases studied had normal error scores in the dichotic listening examinations. There was no connection between the side of the cyst and a unilateral deficit. The results are discussed.

Adolescent↗
PubMed1988

Microsurgical anatomy of the anterior choroidal artery.

The anterior choroidal artery (A.ch.a.) was studied in 140 hemispheres of the human brain. In 50 specimens the artery was cannulated and perfused with acrylic resin, in 20 specimens the A.ch.a., was selectively cannulated and perfused with dye. The artery then was microsurgically dissected and photographically documented. The site of origin of the A.ch.a., its length, outer diameter, course, branching patterns, anastomoses, and areas of supply was recorded. The surgical and diagnostic significance of the A.ch.a. and its importance during surgical procedures are discussed.

Autopsy↗
PubMed1988

[Production and use of monoclonal glucagon and insulin antibodies--reduction of pancreatic insulin in rats by treatment with complete Freund's adjuvant].

Murine monoclonal antibodies against glucagon and insulin were generated by somatic cell hybridization and partially characterized. The monoclonal glucagon antibody K79bB10 exhibited no cross-reaction with gut glucagon. This antibody and the insulin antibody K36aC10 were found of very high concentration in ascites. An ascites dilution of 1:5,000 was used for immunohistochemical staining of insulin and glucagon on Bouin-fixed pancreatic tissue sections. By indirect immunofluorescence technique we could demonstrate a reduction of pancreatic insulin in Lewis rats after treatment with complete Freund's adjuvant. The glucagon staining was not altered. The results were confirmed by radioimmunoassay analysis of pancreatic insulin and glucagon content.

Animals↗