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Biomedical subjects

E Berger

Publications and source records attributed to E Berger.

At least 55 records · Page 3Linked to original sources

Measurement of pi(0)pi(0) production in the nuclear medium by pi(-) interactions at 0.408 GeV/c.

We report on an investigation of the (pi(-),pi(0)pi(0)) reaction by means of measurements of the pi(0)pi(0) invariant mass distributions from pi(-) interactions on H, D, C, Al, and Cu targets at p(pi(-)) = 0.408 GeV/c. The sharp, strong peak in the pi(+)pi(-) invariant mass near 2m(pi) reported by the CHAOS Collaboration is not seen in our pi(0)pi(0) data. However, we do observe a change in the shape of the pi(0)pi(0) invariant mass spectrum for the different targets, indicating that the pi(0)pi(0) interaction diminishes in the nuclear medium as represented by nuclei D, C, Al, and Cu, compared to hydrogen.

Journal Article↗

Search for the CP forbidden decay eta-->4pi(0)

We report the first determination of the upper limit for the branching ratio of the CP forbidden decay eta-->4pi(0). No events were observed in a sample of 3.0x10(7) eta decays. The experiment was performed with the Crystal Ball multiphoton spectrometer installed in a separated pi(-) beam at the AGS (Alternating Gradient Synchrotron). At the 90% confidence limit, B(eta-->4pi(0))</=6. 9x10(-7).

Journal Article↗

Status epilepticus in stroke: report on a hospital-based stroke cohort.

OBJECTIVE: To evaluate occurrence rate, clinical data, and prognostic factors of status epilepticus (SE) after stroke. METHODS: From 1984 to 1994, 3,205 patients were admitted to the Department of Neurology at our institution with first-time strokes. A total of 159 of these patients had first-time poststroke seizures. Among these 159 patients, cases of SE were identified and evaluated. RESULTS: SE was recognized in 31 patients (19%). In 17 patients, SE was the first epileptic symptom (initial SE), and in 4 patients, stroke began with SE (S-SE). In the 14 remaining patients, SE occurred after one or more seizure(s). After a mean follow-up period of 47 months, neurologic deterioration occurred after SE in 15 patients. This deterioration was permanent in two patients. Fifteen patients died; in five patients, death was directly related to SE. Eight of the 17 patients with initial SE and all 14 patients with SE after one or more seizure(s) developed other seizures or SE. S-SE, however, was not a predictive factor for additional seizure(s). CONCLUSIONS: Status epilepticus is common among patients with poststroke seizures. Although the immediate prognosis of patients with status epilepticus is poor, status epilepticus as the presenting sign did not necessarily predict subsequent epilepsy.

Adolescent↗

[Imaging of the microarchitecture and dynamics of the break-up phenomena of the preocular tear film with the aid of laser scanning microscopy].

BACKGROUND: Sufficient and regular wetting of the cornea with a normal preocular tear film is an essential requirement for the accurate visual functioning of the eye. Multiple factors may cause tear film instability. Measuring the break-up time of the preocular tear film is a necessary, clinically reliable means for evaluating tear film stability. We designed a new instrument to observe the preocular tear film at high magnification which can contribute to the in vivo imaging of the physiological and pathophysiological dynamics of the tear film and its break-up phenomena. MATERIALS AND METHODS: To image the tear film phenomena at sufficient magnification (x200) we used a confocal laser scanning microscope. Modification of an additional adaptor allows the tear film to be imaged at high magnification. This study evaluated the dynamics and microarchitecture of the break-up phenomena in the preocular tear film of normal patients and patients with "dry eye". RESULTS: Laser scanning microscopy allows high magnification imaging of the preocular tear film and evaluation of a number of break-up mechanisms. The dynamics and structure of the tear film was analyzed and documented. Based on our observations we formulate a new hypothesis on the break-up mechanism of the preocular tear film caused by alterations in the epithelial surface, for example, an elevation or tear film microparticle. By evaluating video sequences in the fluorescence and reflection modus of the laser scanning ophthalmoscope we also found early thinning of the aqueous layer simultaneously with an intact lipid layer covering the aqueous layer. CONCLUSION: Additional criteria result from using high-magnification microscopy, for example, laser scanning microscopy. This method reveals more microstructures of the corneal surface and the preocular tear film. The morphological representation of break-up phenomena leads to a better understanding of the underlying mechanisms and can be used for further investigations. Confocal laser scanning microscopy supplements the examination facilities and can be used in addition to slit lamp microscopy and to diagnose "dry eye".

Cornea↗

Experimental intrauterine growth retardation alters renal development.

Vascular placental insufficiency is considered a common pathogenic factor in human intrauterine growth retardation (IUGR), resulting in small-for-gestational-age, asymmetric newborns. IUGR neonates experience higher morbidity and mortality rates, as well as a possible contribution towards late sequelae, such as hypertension, and cardiovascular disease in adulthood. To simulate vascular placental insufficiency, an experimental rabbit IUGR model was used. Intrauterine growth retardation was achieved by ligation of 25-30% uteroplacental vessels of half of the fetuses during the last third of gestation. Ischemic fetuses were significantly small, asymmetric, and had a disproportionately small body with a relatively large head. The kidneys from all groups were analyzed for relative estimated glomeruli number (REGN) using an unbiased blind design. The glomeruli number was significantly reduced in the asymmetric IUGR rabbit fetuses, probably due to decreased renal vascular supply. Our results support the concept that the reduced number of glomeruli may contribute to impaired renal function, thus predisposing to neonatal renal dysfunction and late sequelae, such as adult hypertension. This study emphasizes the clinical importance of early IUGR diagnosis and prevention.

Animals↗

Late postoperative results in 1000 work related lumbar spine conditions.

BACKGROUND: Poor results after lumbar spinal surgery have been recorded in compensation cases throughout the world medical literature. It seems that psychosocial factors play an important role in the delay in returning to gainful employment but that chronic postoperative lumbar and lower extremity pain is blamed for this state of affairs. The present series of late outcomes is based on actual physical examination by independent neurosurgical and orthopedic experts appointed by the Workman's Compensation Board, providing an impartial opinion as to the discrepancy between objective findings and failure to reintegrate into the work force. METHODS: One thousand workmen's compensation patients who had undergone lumbar spinal surgery were divided into two groups, one of 600 patients with single operations, evaluated on average 51 months after surgery, and the second of 400 with multiple operations, evaluated on average 38 months postoperatively. RESULTS: Seventy-one percent of the single operation group had not returned to work more than 4 years after the operation, and 95% of the multiple operations group. In none of these cases was there a neurological deficit that precluded gainful employment, the failure to return to work being blamed on chronic postoperative pain. CONCLUSIONS: Although motivational (that is, psychosocial) factors undoubtedly play a role in failure to return to work, the role of chronic pain cannot be ignored. Increased attention must be devoted to ascertaining the etiology of this pain and ways to prevent it.

Accidents, Occupational↗

Protein-coding genes as molecular markers for ecologically distinct populations: the case of two Bacillus species.

Bacillus globisporus and Bacillus psychrophilus are one among many pairs of ecologically distinct taxa that are distinguished by very few nucleotide differences in 16S rRNA gene sequence. This study has investigated whether the lack of divergence in 16S rRNA between such species stems from the unusually slow rate of evolution of this molecule, or whether other factors might be preventing neutral sequence divergence at 16S rRNA as well as every other gene. B. globisporus and B. psychrophilus were each surveyed for restriction-site variation in two protein-coding genes. These species were easily distinguished as separate DNA sequence clusters for each gene. The limited ability of 16S rRNA to distinguish these species is therefore a consequence of the extremely slow rate of 16S rRNA evolution. The present results, and previous results involving two Mycobacterium species, demonstrate that there exist closely related species which have diverged long enough to have formed clearly separate sequence clusters for protein-coding genes, but not for 16S rRNA. These results support an earlier argument that sequence clustering in protein-coding genes could be a primary criterion for discovering and identifying ecologically distinct groups, and classifying them as separate species.

Alanine Dehydrogenase↗

Seizures and epilepsy following strokes: recurrence factors.

BACKGROUND AND PURPOSE: Though there have been many reports on poststroke seizures, there is still much we do not know about them. Using a large cohort of stroke patients we analyzed the characteristics of the seizure(s) and the rate and factors involved in seizure recurrence. METHODS: Out of the 3,205 patients admitted for a first-ever stroke to our department between 1984 and 1994, we retrospectively studied the data of all patients with a first-ever seizure and analyzed their evolution. Two types of seizure(s) were defined: 'early-onset' seizures (occurring within the 14 days following the stroke) and 'late-onset' ones (after the 14th day). RESULTS: 159 patients were included in the study, i.e. 4.96%. There were 116 ischemic strokes and 43 primary hematomas. Cortical involvement was found in 87% of the patients. Early-onset seizures occurred in 57 patients and late-onset ones in 102 patients, 76% of which were observed within 2 years. Follow-up was performed in 135 patients with a mean follow-up period of 47 months; 68 of them presented a seizure recurrence. A 2nd seizure occurred more often in the patients with late-onset seizures (p < 0.01); recurrence was either single (24 patients) or multiple (44 patients). Univariate analysis demonstrated 3 factors for multiple recurrences: hemorrhagic component, low Rankin scale after the initial seizure and occipital involvement. Multivariate analysis determined 2 factors: occipital involvement and late onset of the 1st seizure as a predictive model of multiple recurrences. CONCLUSIONS: This study confirms that poststroke seizures are frequent and must be divided into 2 types: early-onset (</=14 days) and late-onset seizures. It demonstrates that a significantly lower rate of patients with early-onset seizures develop another seizure, i.e. epilepsy, than do patients with late-onset seizures. Other factors are involved in recurrence suggesting that poststroke epilepsy probably occurs in a chronically injured brain. The problem of treatment remain unanswered.

Acute Disease↗

Ruthenium hexaammine trichloride chemography for aggrecan mapping in cartilage is a sensitive indicator of matrix degradation.

We developed a new quantitative histochemical method for mapping aggrecan content in articular cartilage and applied it to models of cartilage degradation. Ruthenium hexaammine trichloride (RHT) forms co-precipitates with aggrecan, the main proteoglycan component of cartilage, and was previously found to be a good fixative in aiding the maintenance of chondrocyte morphology. We show that these RHT-aggrecan precipitates generate a positive chemographic signal on autoradiographic emulsions, in the absence of any radioactivity in the tissue section, via a process similar to the autometallographic process used previously for localization of trace metals ions in tissues. By exploiting the inherent depth-dependence of aggrecan concentration in adult articular cartilage, we demonstrated that the density of silver grains produced by RHT-derived chemography on autoradiographic emulsions correlated with locally measured aggrecan concentration as determined by the dimethylmethylene blue assay of microdissected tissue from these different depths of cartilage. To explore the benefits of this new method in monitoring tissue degradation, cartilage explants were degraded during culture using interleukin-1 (IL-1) or digested after culture using chondroitinase and keratinase. The RHT chemographic signal derived from these samples, compared to controls, showed sensitivity to loss of aggrecan and distinguished cell-mediated loss (IL-1) from degradation due to addition of exogenous enzymes. The RHT-derived chemographic grain density represents an interesting new quantitative tool for histological analysis of cartilage in physiology and in arthritis.

Aggrecans↗

[Emergency neurology consultations in the university hospital setting: contribution of the neurologist to inpatient management].

While outpatient management for chronic neurological diseases is well-established, the impact of inpatient neurological examination in emergency room and university hospital remain largely underestimated. We prospectively studied the role of the neurologist in patient management, in a primary care university hospital. Over a period of 12 months, we prospectively recorded the demographics of patients requiring examination in the emergency room, the initial suspected neurological diagnosis of the emergency room, the final diagnosis of the neurology team, and the patients' outcomes. For each patient, the time between admission, the call and the neurological examination were recorded. Neurological examinations were performed in 2220 patients in whom 75.6 p.100 were performed in the emergency room. These latter patients corresponded to 14 p.100 of all patients admitted in the emergency room. Of examined patients, 52 p.100 were male and mean age was 56.9 +/- 21 years. The time between admission and examination was 32 min. (+/- 36 min), irrespective of the day of the week, and depended on the suspected diagnosis: shorter in stroke and status epilepticus (p<0.05), and longer in loss of consciousness and vertigo (p<0.01). Forty-four percent of the examinations took place in the evening and night. The reasons for examinations were: stroke (28.3 p.100), epilepsy (17.7 p.100), headaches (8.4 p.100), loss of consciousness (7.9 p.100), cognitive dysfunctions (4.1 p.100), neuropathies (4 p.100) and miscellaneous (8.1 p.100). Neurological examinations modified neurological diagnosis and treatment in more than 86 p.100 of the patients. Following neurological examination, 17.2 p.100 of the patients were able to go home, while the rest were admitted to the stroke unit (27.2 p.100), the general neurological unit (27.3 p.100) or in other departments (28.3 p.100), of which intensive care unit (5.3 p.100) or neurosurgery (5.9 p.100). Emergency neurologic examination improves neurological diagnosis and has a positive impact both on treatment and, more globally, in patient management.

Consultants↗

[New therapeutic strategies in multiple sclerosis].

Until a few years ago, the focus of MS therapy was mainly on the symptomatic approach. Several rigorous clinical trials concerning mainly relapsing-remitting forms were conducted recently. As a result of these, therapeutical views have changed. Elevated doses of methylprednisolone, used during a short period have significantly improved the handicap; but impact over a longer time is unknown. It has now been demonstrated that beta interferons reduce the frequency of relapses, modify the handicap favourably and improvements are clearly shown on MRIs. Therefore MRI has become an invaluable tool for the evaluation of the efficacy of new drugs. Recently, there have been positive results made in progressive MS. Two other drugs, Copolymer and Immunoglobulins have also shown encouraging results but other studies are still necessary. The role of some immunosuppressive agents, but mainly the role of mitoxantrone are now better understood. These results are encouraging but they have also raised a lot of questions such as: how can these drugs be used in other forms of MS; what is their long-term impact on the disease; what is the mechanism of their action; what is the etiopathogeny of MS? Clinical trials are being conducted to answer these questions and to study the usefulness of combined therapies. Even though these results have been positive, other therapies which focus on spasticity, fatigue, sphincter, dysfunction and psychosocial problems must not be neglected.

Adjuvants, Immunologic↗

Gastrointestinal stromal sarcomas.

BACKGROUND: Gastrointestinal stromal sarcomas are a rare group of malignancies originating in the bowel wall. METHODS: The treatment of 12 patients with gastrointestinal stromal sarcoma who underwent operation between 1994 and 1998 was reviewed. RESULTS: Eight tumours originated in the stomach; others were in the small bowel or rectum. Five of the tumours were of myogenic origin, two were gastrointestinal autonomic nerve tumours, one was a mixed neural-myoid tumour, and four could not be differentiated. Complete resection was possible in ten patients; in two of the ten en bloc resection of adjacent organs was required to ensure adequate margins. The tumours in the remaining two patients were irresectable because of diffuse intra-abdominal metastatic disease. All patients who underwent complete resection were alive after 4-48 (median 14) months. Two of the ten patients developed recurrence, which was reresected completely. The patients with metastatic disease died less than 1 year after operation. CONCLUSION: Aggressive surgical resection, achieving complete resection, can lead to prolongation of life and may be a potential cure for patients with gastrointestinal stromal sarcoma.

Adult↗

Correlation of duplex sonography findings and portal pressure in 375 patients with portal hypertension.

OBJECTIVE: The purpose of this study was to determine the potential usefulness of duplex sonography in the grading of portal hypertension. SUBJECTS AND METHODS: Duplex sonography of the portal vein system and measurement of the portal pressure and portosystemic pressure gradient were performed in 375 patients before placement of transjugular intrahepatic portosystemic shunts. Subgroups included patients with recent variceal bleeding (n = 296) and patients with refractory ascites without previous variceal bleeding (n = 79). A matched cohort of 100 patients without portal hypertension was also examined. Differences between the groups in portal and splenic vein diameter, flow velocity, congestion index, and hepatic arterial resistive index were assessed using the Wilcoxon rank sum test. RESULTS: Compared with healthy individuals, our patients had an increased portal vein diameter (+30%, p < .001), decreased portal vein flow velocity (-44%, p < .001), and increased congestion index (+185%, p < .001). A portal vein diameter greater than 1.25 cm or a portal vein flow velocity less than 21 cm/sec indicated portal hypertension with a sensitivity and specificity of 80%. If the congestion index exceeded 0.1, portal hypertension was diagnosed with a 95% sensitivity and specificity. The portal pressure and gradient correlated only weakly (r < .2, p < .05) with sonographic variables. Using multivariate analysis, subgroups with variceal bleeding or refractory ascites did not show differences in hemodynamics, including pressures. CONCLUSION: Duplex sonography contributes to the diagnosis of portal hypertension but does not allow its grading. Similarity of portal hemodynamics between patients with variceal bleeding and patients with refractory ascites suggests that additional factors determine the respective clinical presentation.

Female↗

Interferon gamma, IL2, IL4, IL10 and TNFalpha secretions in multiple sclerosis patients treated with an anti-CD4 monoclonal antibody.

In order to better understand the mechanisms of action of a monoclonal anti-CD4/BF5 antibody(mAb), cytokine secretions were studied in 14 multiple sclerosis (MS) patients treated in a phase 1 trial. Secretion patterns of IFNgamma, IL2, IL4, IL10 and TNFalpha by peripheral blood mononuclear cells were studied before (DO) and after (D30) the treatment. We decided to undertake this study because in a previous one we observed no variations in serum levels of TNFalpha, IFNgamma, IL1, IL6. Results showed significant reductions in IFNgamma, IL2 and TNFalpha secretions after treatment. The anti-CD4 mAb seemed to act on both Th1- and Th2-cells but with preferential action on Th1-cells. Results on Th2-cells were less obvious even though a significant decrease in IL10 was observed. There was no correlation between any of the immunological markers studied and disease activity. This study demonstrates that pharmacological modifications of the CD4 receptor can induce variations in several cytokine secretion levels. It also stresses the role played by Th1- and Th2-cells in the etiopathogenesis of MS.

Adult↗