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Biomedical subjects

G Beer

Publications and source records attributed to G Beer.

At least 19 recordsLinked to original sources
PubMed2005

Evidence for a kaon-bound state K(-)pp produced in K(-) absorption reactions at rest.

We have searched for a deeply bound kaonic state by using the FINUDA spectrometer installed at the e(+)e(-) collider DAPhiNE. Almost monochromatic K(-)'s produced through the decay of phi(1020) mesons are used to observe K(-) absorption reactions stopped on very thin nuclear targets. Taking this unique advantage, we have succeeded to detect a kaon-bound state K(-)pp through its two-body decay into a Lambda hyperon and a proton. The binding energy and the decay width are determined from the invariant-mass distribution as 115(+6)(-5)(stat)(+3)(-4)(syst) MeV and 67(+14)(-11)(stat)(+2)(-3)(syst) MeV, respectively.

Journal Article↗
PubMed2005

Measurement of the kaonic hydrogen x-ray spectrum.

The DEAR (DAPhiNE exotic atom research) experiment measured the energy of x rays emitted in the transitions to the ground state of kaonic hydrogen. The measured values for the shift epsilon and the width Gamma of the 1s state due to the K(-)p strong interaction are epsilon(1s)=-193 +/- 37 (stat) +/- 6 (syst) eV and Gamma(1s)=249 +/- 111 (stat) +/- 30 (syst) eV, the most precise values yet obtained. The pattern of the kaonic hydrogen K-series lines, K(alpha), K(beta), and K(gamma), was disentangled for the first time.

Journal Article↗
PubMed2002

Fabry disease in patients with hypertrophic cardiomyopathy (HCM).

Fabry disease is an X-linked recessive lysosomal storage disorder with variable phenotype characterized by the accumulation of glycosphingolipid in various tissues. Unlike patients with the classical systemic Fabry disease entity, who present with multiple organ involvement, patients with a cardiac variant of Fabry disease are characterized mainly by myocardial hypertrophy. Therefore, the cardiac variant of Fabry disease may be defined as a cardiomyocytic storage disorder, thus, mimicking the clinical features of hypertrophic obstructive and especially non-obstructive cardiomyopathy. In patients with unexplained left ventricular hypertrophy the diagnosis of a cardiac variant of Fabry disease is performed by light- and electron microscopic evaluation of endomyocardial catheter biopsy specimens and/or serologic investigations (decreased activity of alpha-galactosidase A in plasma or leucocytes). Several studies show that between 4% and 8% of unselected patients with the clinical features of hypertrophic non-obstructive cardiomyopathy have a cardiac variant of Fabry disease. In each patient with unexplained myocardial hypertrophy concealed myocardial storage disease, especially cardiac Fabry disease has to be considered and should be ruled out or confirmed by endomyocardial catheter biopsy. This is important because of the recently reported alpha-galactosidase A enzyme replacement therapy in Fabry disease. Randomized, multicenter studies are mandatory to test the hypothesis that enzyme replacement therapy leads to a beneficial clinical effect in the cardiac variant form of Fabry disease and may prevent the progression of the disease in asymptomatic patients.

Aged↗
PubMed2002

[Methods, indications and validation of intraoperative nerve conductivity testing].

During nerve surgery, electrodiagnostic methods are applied to assess the availability and viability of nerve fibers and to adjust operative measures accordingly. The validity of this procedure is verified by histology and by the outcome of the operation. This paper explains the techniques of intraoperative nerve action potential (NAP) and somatosensory evoked potential (SEP) recording, how to interpret the electrodiagnostic results, and describes both the special features and the limitations of the methods. We found reliable results of neurography, detecting the presence or absence of spontaneous nerve regeneration across a lesion in continuity months before the reinnervation reached its final target. Based on our results, we suggest that NAP recording of the exposed nerve can widely prevent unnecessary nerve or fascicle resection. Besides this important indication, the nerve function evaluation was successfully used in nerve surgery whenever the quality of the nerve parenchyma was crucial to the operative management. Further indications such as evaluating brachial plexus lesions and the condition of nerve roots, judging the proximal coaptation site in nerve reconstruction, tracing the site of a nerve lesion and identifying the pathophysiology of nerve malfunction are exemplified. Intraoperative nerve conductivity testing should not be considered as a replacement of but rather as a complement to preoperative clinical, electrophysiological and imaging evaluations and a thorough intraoperative morphological examination.

Adolescent↗
PubMed2000

Aggressive angiomyxoma: irradiation for recurrent disease.

BACKGROUND: Aggressive angiomyxoma (AAM) is a tumor of the soft tissues predominately occurring in the genital and pelvic area with a strong propensity to local recurrences. The entity was first described in 1983. The tumor is regarded as low-grade sarcoma by some authors; its cause and pathogenesis are presently unknown. PATIENT AND METHOD: This is a case report on a 27-year-old man who underwent 4 surgical procedures of the left lower extremity because of a recurrent soft tissue neoplasm, initially (August 1993) diagnosed as a myxolipoma. The patient suffered from recurrences in February 1995, September 1996 and February 1998. The diagnosis was revised at the time of the latest recurrence. A palliative resection with macroscopic residuals left was performed in February 1998, followed by a radiation therapy with 56 Gy total dose and a concomitant administration of the radiosensitizer razoxane per os. The single radiation doses were 200 cGy 5 times a week. RESULTS: The small residuals of the tumor obviously regressed although an objective response could not be shown because the lesion was not clearly measurable. A follow-up 2 years after the radiation treatment revealed no recurrence. The time of the local control achieved as yet is already longer than any former time to regrowth between the surgical procedures. This is, to our knowledge, the first description of a therapeutic irradiation of a recurrent aggressive angiomyxoma. CONCLUSION: Radiation therapy combined with the sensitizer razoxane is able to control a recurrent AAM for an unknown time. It remains open whether a radiation treatment alone would have had a similar effect.

Adult↗
PubMed1994

Transient neurological events during dipyridamole stress test: an arterial steal phenomenon?

Dipyridamole-associated adverse neurological side effects have not been extensively described. We present two cases of dipyridamole-associated transient motor neurological events with no evidence of residual neurological deficits detected clinically or by head CT. The patients showed no evidence of significant extracranial (internal carotid) artery disease. We propose the presence of a regional cerebral perfusion disturbance due to an intracranial vascular steal phenomenon as the mechanism for the above side effects of dipyridamole.

Aged↗
PubMed1992

[Case study of a Legionella epidemic in a rehabilitation clinic].

A series of nosocomial Legionella infections in a rehabilitation center is reported. In a three months period a total of 10 pneumonias with 3 deaths occurred (8 patients, 1 companion, 1 staff member). Serologic analysis proved additional Legionella infections within the nursing staff. The warm-water system was proved to be the source of infection by isolating Legionella pneumophila serogroup 1 subtype Pontiac both in warm-water and patients samples. The air conditioning system could not be ruled out as another (secondary) route of exposure because of shortcomings in construction. Conclusions about prevention and the course of the disease are discussed and standards for warm-water and air conditioning systems are proposed.

Adult↗
PubMed1990

[DNA analysis of HLA class II and III genes in sudden infant death (SIDS)].

In 39 cases of SID we studied the polymorphism of HLA-class II genes DRB and DQB and HLA-class III genes C4 (C4A and C4B, genes encoding the fourth complement component) and 21-hydroxylase (21OH-A and 21OH-B, genes encoding the enzyme 21-hydroxylase of the cortisol pathway) by DNA analysis. This study was performed in cooperation with the Institute of Legal Medicine, University of Munich. Compared to healthy controls the percentage of C4B gene deletions, C4B gene duplications (C4B "short") and 21OH-A gene deletions is increased in SIDS. The deviations are statistically not significant. The analysis of the HLA-DR alleles revealed a significant decrease of HLA-DR2 in SIDS compared to controls (p = 0.0016, pc = 0.016). The results of this study indicate a possible role of C4B/21OH-A gene defects as a risk factor in a subgroup of SID cases. This hypothesis has to be confirmed by studying further cases.

Chromosome Aberrations↗
PubMed1989

[HIV infection in legal autopsies].

Since May 1987 all postmortem cases at the Munich Institute of Forensic Medicine were screened for HIV-antibodies. If possible, testing was carried out before the postmortem examination in order to allow specific protective measures. 19 of 2631 consecutively tested corpses (= 0.7%) were HIV-infected. Since 1986, the onset of occasional testing, we found 29 HIV-infections. 24 of these were men, 5 were women. At least 15 were i.v.-drug abusers und 8 were homosexuals. In post mortem testing of body fluids false-positive results can be recognized easily even by ELISA-testing alone. Additional testing of several body fluids other than blood and especially of brain tissue proved to be valuable and yielded reliable results. Body fluids and tissues of HIV-infected corpses are potentially infectious as long as one week after death.

AIDS Serodiagnosis↗