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Biomedical subjects

G Brill

Publications and source records attributed to G Brill.

At least 19 recordsLinked to original sources

[Differential diagnosis of space demands in the cerebellopontine angle].

Most of the space demands in the cerebellopontine angle lie extra-axially. Important structures run within the cisterns of the cerebellopontine angle, such as the trigeminal, facial and vestibulocochlear nerves as well as the anterior inferior and posterior inferior cerebellar arteries and the veins which lead to the petrosal sinus. The most common space demands are caused by acoustic neuromas, meningeomas, vascular ectasia and aneurysms. Less common are epidermoid and other schwannomas as well as metastases, paragangliomas and arachnoidal cysts. Intra-axial tumours in the area of the cerebellopontine angle include the medulloblastoma, astrocytoma and the ependymoma, which occurs predominantly in children, in addition to the uncommon choroid plexus papilloma. Nearby, there are also space demands around the petrous bone, such as cholesterol granuloma, malignant otitis media, paraganglioma and metastases. For differential diagnosis, an understanding of the space requirements of the tumours in the cerebellopontine angle is needed in addition to knowledge of the anatomical structures.

Brain Stem Neoplasms↗

Bier's block; 100 years old and still going strong!

In August 1908 Karl August Bier, Professor of Surgery in Berlin, described a new method of producing analgesia of a limb which he named 'vein anesthesia'. Bier first presented his new method of intravenous regional anesthesia (IVRA) at the 37th Congress of the German Surgical Society on 22 April, 1908, only 10 years after his significant communication on spinal anesthesia (1). His method, which now bears his name, consisted of occluding the circulation in a segment of the arm with two tourniquets and then injecting a dilute local anesthetic through a venous cut-down in the isolated segment. Bier had the good fortune to use procaine, the first safe injectable local anesthetic that had been synthesized by Einhorn in 1904.

Adjuvants, Anesthesia↗

Differential response of platelets to chemokines: RANTES non-competitively inhibits stimulatory effect of SDF-1 alpha.

BACKGROUND: Among the chemokines related to CXC and CC receptor groups and released from platelets, leukocytes and endothelial cells, SDF-1, TARC and MDC have been found to be platelet agonists. Platelets do not contain SDF-1 alpha. In contrast, RANTES is constitutively present in platelet alpha-granules and released upon platelet activation. OBJECTIVES: To study a possible role of RANTES as a modulator of SDF-1 alpha effect on platelets, in relation to CXCR4 and various CC receptors. METHODS: CXCR-4 (CXCL12) receptor expression and platelet activation were evaluated by flow cytometry, platelet deposition was studied by cone and plate(let) analyzer, and platelet aggregation by turbidometric aggregometry. RESULTS: Flow cytometry studies revealed similar expression of CXCR-4, the specific receptor of SDF-1 alpha on intact, inactivated, and activated platelets. Preincubation of platelets with RANTES affected neither CXCR-4 expression, nor SDF-1 alpha binding to the platelet membrane. In the presence of fibrinogen, SDF-1 alpha activated gel-filtered platelets. RANTES did not activate platelets, but substantially (by 70%) inhibited SDF-1 alpha-induced fibrinogen binding. Similarly, RANTES abrogated the promoting effect of SDF-1 alpha on whole blood platelet adhesion to endothelial cell monolayer under venous flow conditions. In platelet-rich plasma, RANTES moderately inhibited SDF-1 alpha-induced platelet aggregation, while it did not affect aggregation induced by thrombin-receptor activation peptide, adenosine diphosphate, or phorbol 12-myristate 13-acetate. A synergistic inhibitory effect of RANTES and prostaglandin E1 used at subthreshold concentrations, on SDF-1 alpha-induced aggregation and SDF-1 alpha-induced fibrinogen binding to platelets was observed, which may suggest involvement of RANTES in a cAMP-dependent signal transduction pathway. CONCLUSIONS: RANTES non-competitively inhibits activation of platelets by SDF-1 alpha, and thus may play a regulatory role in platelet response to inflammation.

Blood Platelets↗

[Lumbar arachnoiditis as differential chronic spinal symptoms diagnosis].

Lumbar epiduro-arachnoiditis is an infectious disease of the three mengial layers. It is often caused by surgical interventions on the spine. In this survey etiologic factors, clinical symptoms and radiological findings are compared. The radiologic classification of Delamater is described by three clinical cases. The diagnostic value of different procedures such as myelography, postmyelographic computed tomography and MR imaging is evaluated.

Arachnoid↗

Evaluation of the VersaMed portable ventilator: clinical trials.

The VersaMed 201 is a lightweight, computer-controlled, electrically driven ventilator, designed for transport, home-ventilation and field use. We have evaluated the device in human beings with healthy and pathological lungs. In the first part of the study, the VersaMed was substituted for a standard operating room ventilator for 15-30 min during elective surgery in 20 subjects. In the second stage of the study, 20 patients with lung pathology who were being ventilated in the critical care department were transferred to the VersaMed for a 30-min period. In all the patients studied, arterial blood gases, haemodynamic parameters and other respiratory variables were maintained at similar values seen with the standard ventilators used. We conclude that the VersaMed 201 is suitable for use in human beings with healthy and pathological lungs as a reliable, portable ventilator.

Adult↗

Safety and immunogenicity of a novel mammalian cell-derived recombinant hepatitis B vaccine containing Pre-S1 and Pre-S2 antigens in children.

We tested the safety and immunogenicity of the new recombinant hepatitis B virus (HBV) vaccine produced via expression of the Pre-S1, Pre-S2 and S protein components of the hepatitis B surface antigen (HBsAg). A reduced dose (2.5 micrograms) of the vaccine (Bio-Hep-B) was tested in children aged 4-9 years and was compared to a 10 microgram dose of a licensed vaccine (Engerix-B) in a randomized manner. Both vaccines were administered in 3 doses (0, 1 and 6 month intervals). Adverse events were collected 5 days following each vaccination by a diary card provided to the parents. Immunogenicity was tested by measuring anti-hepatitis B surface antibody (anti-HBs). A total of 217 children were enrolled (162 in the Bio-Hep-B group and 55 in the Engerix-B group). Total adverse events were observed in 35% of the Bio-Hep-B group and 33% of the Engerix-B group, with no differences when each of the potential adverse events was considered. Titers were within the expected range (geometric mean titers post dose 1, 2 and 3 were 45.8, 8360.2 and 1445.7, respectively, for Bio-Hep-B and 36.3, 10316.1 and 1898.7, respectively, for Engerix-B). A trend toward better immunogenicity with Bio-Hep-B was observed at early visits when measured by both seroconversion (anti-HBs > or = 2.1 mIU ml-1) rate and seroprotection (anti-HBs > or = 10 mIU ml-1) rate; however, statistical significance was not reached. We conclude that in children, Bio-Hep-B vaccine at a reduced dose was as safe and as immunogenic as Engerix-B given at the regular pediatric dosage.

Child↗

[Neurological symptoms associated with vitamin E deficiency].

Children deficient in vitamin E have various neurologic symptoms. 2 cases representing different mechanisms of this vitamin deficiency are reported. A 15-year-old boy with fat malabsorption due to cystic fibrosis who was diagnosed as being vitamin E deficient (< 0.5 mg/l), had typical neuropathies. On the other hand, a 12-year-old Beduin girl had isolated vitamin E deficiency, as well as neurological symptoms suggestive of Friedrich's ataxia. Vitamin E supplementation by intramuscular injection in the first case and per os in the second led to significant improvement in neurological symptoms.

Adolescent↗

Epithelial-mesenchymal conversion of dermatome progenitors requires neural tube-derived signals: characterization of the role of Neurotrophin-3.

Development of the somite-derived dermatome involves conversion of the epithelial dermatome progenitors into mesenchymal cells of the dermis. In chick embryos, neural tube-derived signals are required for this conversion, as the interposition of a membrane between neural tube and somites results in a failure of the dermatome to lose its epithelial arrangement. However, dermis formation can be completely rescued by coating the membranes with Neurotrophin-3, but not with the related molecule Nerve growth factor. Neurotrophin-3 was also found to be necessary for dermatome dissociation using in vitro explants or partially dissociated dermomyotomes. The functional relevance of these observations was investigated by neutralizing endogenous Neurotrophin-3 using a specific blocking antibody. Antibody-treated embryos revealed the presence of tightly aggregated cells between myotome and ectoderm instead of the loose dermal mesenchyme observed in embryos treated with control antibodies. As previous studies have demonstrated the presence of Neurotrophin-3 in the neural tube, these results suggest that it may be a necessary neural tube-derived signal required for early stages of dermis formation.

Animals↗

[Nuclear magnetic resonance tomography for improving the differential diagnosis of pathologic changes in the scrotal contents].

A total of 75 patients with scrotal pathology were examined using magnetic resonance imaging (MRI). The diagnostic results were compared with operative and histological findings and with the sonographic results available. Compared with sonography, MRI showed diagnostic advantages in the detection and characterization of malignant tumors and in the exclusion of non-tumorous testicular pathology (old torsions, periorchitis, old hematomas). No false-negative results were found by MRI. False-positive results were found in 2 out of 75 MRI examinations. The possibility of showing tunica albuginea, of imaging testes in various planes and its diagnostic accuracy of about 88% as well as the lack of ionizing irradiation make MRI the most reliable form of diagnostic imaging in the classification of scrotal pathology. Sonography (51/75) showed high sensitivity in detecting testicular disease (90%), but its specificity (55%) was disappointing and could not be quantified with regards to the differentiation of testicular cancer.

Adolescent↗

Psychosocial correlates of clinical depression after psychiatric in-patient treatment: methodological issues and baseline differences between recovered and non-recovered patients.

General methodological and design issues in research on psychosocial outcome predictors of clinical depression are discussed, and the first stage of a study of discharged depressed in-patients is presented. It involved 115 recovered and 75 non-recovered such patients who were compared regarding stress factors, social support, personality and coping styles. While there were few differences between recovered and non-recovered patients with respect to stable personality traits, recovered patients were less likely to have had severe long-term life difficulties, and their coping style differed: it was characterized by more negative appraisals of stressful situations, greater problem avoidance, less palliative activities, and a lesser inclination to solicit social support. Whereas among women without partners, as well as men, non-recovery was also associated with less support from friends, in particular psychological-emotional support in crises, non-recovered women with partners had much more such support. The results are discussed with reference to the existing literature on outcome correlates of clinical depression.

Adaptation, Psychological↗

BHK-21-derived cell lines that produce basic fibroblast growth factor, but not parental BHK-21 cells, initiate neuronal differentiation of neural crest progenitors.

We present evidence that basic fibroblast growth factor (bFGF)-producing cells stimulate primary differentiation of neurons from neural crest progenitors. Baby hamster kidney (BHK-21) cells were stably cotransfected with plasmid pSV2/neo, which contains the gene conferring resistance to the neomycin analog G418 and expression vectors containing the human bFGF cDNA. Various clones, which differed in their bFGF production levels, were isolated. Homogeneous neural crest cells were cultured on monolayers of bFGF-producing, BHK-21-derived cell lines. While the parental BHK-21 cells, which do not produce detectable bFGF, had poor neurogenic ability, the various bFGF-producing clones promoted a 1.5- to 4-fold increase in neuronal cell number compared to the parental cells. This increase was correlated with the levels of bFGF produced by the different transfected clones, which ranged between 2.3 and 140 ng/mg protein. In contrast, no stimulation of neuronal differentiation was observed when neural crest cells were grown on monolayers of parental BHK cells transfected with plasmid pSV2/neo alone, or on a parental BHK-derived clone, which secretes high amounts of recombinant vascular endothelial growth factor (VEGF). Furthermore, the neuron-promoting ability of bFGF-producing cells could be mimicked by addition of exogenous bFGF to neural crest cells grown on the parental BHK line. A similar treatment of neural crest cells grown on laminin substrata, instead of BHK cells, resulted in increased survival of non-neuronal cells, but not of neurons (see also Kalcheim, C. 1989, Dev. Biol. 134, 1-10). Taken together, these results suggest that bFGF stimulates neuronal differentiation of neural crest cells by a cell-mediated signalling mechanism.

Animals↗

[Tuberous sclerosis: broadening of the diagnosis using MR tomography and computed tomography].

Ten children and a 22-y old women with tuberous sclerosis were studied. All children were epileptic but only 8 had skin lesions (white spots, sebaceous adenoma), 4 had rhabdomyoma of the heart and 4 children had astrocytoma of the retina; only in 4 children was the entire triad of tuberous sclerosis seen. The young woman with a hemorrhage of an angiolipoma of the kidney had no other symptoms of tuberous sclerosis. All patients had pathologic CT and MRT findings; 4 different types of lesion were seen in MRT. In order to elucidate human genetic aspects and to demonstrate the underlying disease all children with epileptic disorders and also all patients without the full triad of symptoms should be examined by MRT.

Adult↗

[Clinical value of the ultrafast gradient echo sequence "Quickflash"].

It is possible to develop faster sequences with 6 mT/m gradient field strength. However, the short gradient switch times which are advantageous for a better image contrast cannot be achieved. Using longer measurement times the influence of the preparation pulses is less dominant. The image quality of the quickflash is poorer than that of conventional SE and GE sequences. In some cases, especially for outline views and in the evaluation of Gd inflow into pathologic tissue or in restless patients, we use the quickflash in clinical routine.

Brain Diseases↗