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Biomedical subjects

R Weber

Publications and source records attributed to R Weber.

At least 163 records · Page 9Linked to original sources
PubMed1998

Identifying donor concerns to increase live organ donation.

Increasing organ donation from live donors is a means to increase the pool of kidneys available for transplantation. To increase the number of live kidney donors, the major concerns of donors must be determined and addressed. This article describes the health and socioeconomic concerns of 61 live kidney donors from the Johns Hopkins Institutions between February 1, 1995 and December 1, 1997. Seventy-five percent of donors reported they had concerns, the most common ones being the effect of donation on their future health, how many work days they would miss, the ability to return to the same activities, and the pain they would experience. Other reported concerns consisted of fear of dying, the risks to a future pregnancy with one kidney, the fear that a son or daughter may need a kidney in the future, and the impact of donation on the family health insurance premium. Interventional strategies including the use of the laparoscopic donor nephrectomy procedure are offered to address these concerns.

Absenteeism↗
PubMed1998

[Is chronic laryngitis associated with Helicobacter pylori? Results of a prospective study].

H. pylori is found in the stomach of patients with chronic gastritis. The infection is usually transmitted by the gastro-oral route and bacteria could be identified in saliva and dental plaque. An essential cause of chronic laryngitis is gastroesophageal reflux. The aim of the study was to evaluate if a H.pylori-associated chronic laryngitis exists. 38 patients with chronic laryngitis underwent gastroscopy. Biopsies were taken from the gastric antrum and body, lower, middle and upper esophagus. H. pylori was diagnosed by rapid urease test and histology. 14 of the patients (36.8%) were H.pylori-positive, but the bacteria could not be identified between stomach and larynx. 24 patients were H. pylori-negative. Seven patients (18.4%) suffered from esophagitis, six of these patients were H. pylori-negative. The H. pylori-infected patients received triple therapy for one week, in case of esophogitis Omeprazole 20 mg BID was prescribed. Six weeks later a follow-up endoscopy was performed. The eradication rate was 12/14 (85.7%), in all patients with reflux the esophagitis was cured. The laryngitis was clinically and endoscopically unchanged in ten of the twelve (83.3%) patients after successful treatment for H. pylori; in the remaining two patients as well as in the two H. pylori-positive patients the laryngitis was improved. In six out of the seven patients with esophagitis the laryngitis had healed completely and was improved in the remaining patient. It may be concluded that there is no evidence for the existence of H. pylori-associated laryngitis, suggesting that acid reflux is the underlying etiology.

Adult↗
PubMed1997

Extranasopharyngeal angiofibroma in a 15-month-old child.

Angiofibromas are usually characterized by typical location with involvement of the posterior nasal cavity and nasopharynx. They are most commonly found in adolescent males. Despite these facts, a case of an angiofibroma presented in a 15-month-old boy at an atypical site anterior and medial to the lacrimal sac. The tumor was resected via an endonasal, micro-endoscopic approach avoiding an external incision.

Angiofibroma↗
PubMed1997

Can response to partial sleep deprivation in depressed patients be predicted by regional changes of cerebral blood flow?

The possible predictive value of regional cerebral perfusion patterns with respect to the response to partial sleep deprivation (PSD) was evaluated in 15 major depressive patients (mean age = 54.9 years, mean Hamilton depression score = 21.6). Patients were studied with single photon emission computed tomography with technetium-99 m-D,L-hexamethyl-propylene amine oxime. Scans were performed on the morning before and after (at 08.00 h) PSD. Responders to PSD had significantly higher perfusion in the right orbitofrontal cortex than did non-responders before PSD. Multiple regression analysis indicated that right orbitofrontal/basal cingulate perfusion (r = -0.77, P < 0.001) before PSD, and left inferior temporal perfusion (r = 0.59, P = 0.01) after PSD, were fairly accurate predictors of change in Hamilton depression scores. Thus, it appears that the orbitofrontal cortex and the cingulate are involved in PSD and may serve as predictors of therapeutic response.

Adult↗
PubMed1997

[Meningitis after acute Borrelia burgdorferi infection in HIV infection].

HISTORY AND CLINICAL FINDINGS: A 39-year-old HIV positive patient developed myalgia, headache and cough 4 weeks after a tick bite. His temperature was 37.4 degrees C and a circular pale erythema was noted over the left lower leg. INVESTIGATIONS: C-reactive protein was raised to 120 mg/l, white blood cell count was 5860/microliter, CD4-lymphocyte count 250/microliter. The chest radiogram showed pneumonitic infiltration in the left lower lobe. There were IgM antibodies against Borrelia burgdorferi. TREATMENT AND COURSE: Left lower lobe pneumonia and chronic erythema migrans were diagnosed and he was given oral azithromycin (500 mg on the first day and 250 mg for 4 days). The pneumonia cleared up, but 2 weeks later he developed symptoms of meningitis (496 cells per microliter, 87% lymphocytes, positive Borrelia burgdorferi antibody titer), which quickly and lastingly responded to ceftriaxon (2 g daily by brief infusion for 14 days). CONCLUSION: This immune-compromised HIV-infected patient developed disseminated borreliosis with CNS involvement 2 weeks after the occurrence of chronic erythema migrans. The initial treatment of the latter with azithromycin was unable to prevent the meningitis. It is unlikely that there was a causal connection between the borreliosis and the pneumonia.

Adult↗
PubMed1997

Electrodynamic Trapping of Aerocolloidal Particles: Experimental and Theoretical Trapping Limits

Aerocolloidal particles have been trapped from an uncharged source aerosol using an electrodynamic balance. Graphite and soot particles were charged photoelectrically using a Xe2 (172 nm) excimer lamp, while particles of titanium dioxide, sodium nitrate, and diethylhexyl sebacate (DEHS) were charged using a unipolar corona charger prior to injection into the chamber. It was found that the Stokesian drag force produced by convection in the balance chamber can destabilize the levitated microparticle when it exceeds the electrostatic force required to center the particle. Although the electrostatic restoring force can be increased by increasing either the particle charge or the ac field strength, charging of the particles is more difficult as the particle diameter is decreased, which gives rise to a trapping limit. Monodisperse DEHS particles were used to determine the experimental trapping limit for unipolar charging. For the experimental apparatus used in this study, a diameter of about 1 μm was found to be the trapping limit for DEHS. Results are compared to the theoretical trapping limit calculated by a force balance on a particle exposed to motion of the surrounding gas.

Journal Article↗
PubMed1997

Laparoscopic assisted live donor nephrectomy--a comparison with the open approach.

Live donor renal transplantation provides significant advantages when compared with cadaveric donor renal transplantation in terms of improved patient and graft survival, a lower incidence of delayed function, and a shorter waiting time. Yet despite these advantages, live donors continue to be an under utilized source of kidneys for transplantation. Disincentives to live donation include the length of hospitalization, postoperative pain, cosmetic concerns, and the prolonged convalescence associated with the donor operation. In many instances minimally invasive video-assisted techniques have proven more efficacious than standard open procedures in terms of patient discomfort, length of hospital stay, cost, and length of time until the patient can return to full activity. Laparoscopic live donor nephrectomies are being performed at our institution in an attempt to make live donation more attractive to the potential donor. The purpose of this study was to retrospectively review the results of laparoscopic live donor nephrectomy (LapNx) and to compare them with those obtained using the standard open approach (OpenNx). Ten consecutive LapNx were performed from February 1995 through April 1996. The control group consisted of the 20 consecutive OpenNx performed at the same institution from January 1991 through January 1995 immediately before the initiation of the LapNx program. Live donors were considered candidates for LapNx if they possessed at least one kidney with normal renal anatomy with single renal vessels and a single ureter. LapNx was safely performed in all cases. No patients required open conversion or blood transfusions. The allograft warm ischemic time for the laparoscopic cases was 4.2+/-1.3 min. All kidneys harvested laparoscopically produced urine on the table immediately upon revascularization. Presently nine of the ten recipients have functioning allografts. At three months posttransplant the calculated recipient creatinine clearances were 67.0+/-11.5 ml/min and 64.8+/-21.4 ml/min for the LapNx and OpenNx groups, respectively (P=NS). The LapNx donors had a significantly decreased estimated blood loss, shorter time until resumption of oral intake, decreased postoperative pain (in terms of decreased analgesic requirements), shorter hospitalization, and a shorter interval until the resumption of full activities (P<0.05 for all). In addition, the LapNx group donors returned to work sooner than the OpenNx group (3.9+/-1.6 wk vs. 6.4+/-3.1 wk, respectively) (P=0.024). Four individuals agreed to donate a kidney only after learning of the availability of the laparoscopic approach. We conclude that laparoscopic live donor nephrectomy is technically feasible. In addition, it may offer significant advantages over the standard open approach in terms of patient comfort and convenience. These advantages may make live donor renal transplantation more attractive to prospective donors. The potential decrease in hospitalization and convalescence may also prove to be financially advantageous. We believe that further careful study of this procedure is warranted.

Adult↗
PubMed1997

[Cervical lymphadenitis in an immunocompetent patient: Mycobacterium gordonae as the cause?].

HISTORY AND FINDINGS: A 76-year-old man went to an ENT outpatient clinic because of stabbing pain in the left throat and difficult swallowing. He was found to have tonsillitis on the left and cervical lymphadenitis. The symptoms regressed on treatment with amoxycillin and clavulanic acid, but the cervical lymphadenitis persisted. Fine-needle biopsy of the cervical swelling was not diagnostic. Computed tomography of the neck showed an encapsulated liquid space-occupying lesion with infiltration of surrounding soft tissues. TREATMENT AND COURSE: The cervical lymph-node mass was excised and histologically found to contain epithelioid granulomas with a few giant cells and scattered centrally caseous necroses. Tuberculostatic treatment was started; drainage fluid from the wound grew acid-fast bacilli, identified by gene probe as Mycobacterium gordonae. CONCLUSIONS: Mycobacterium gordonae is ubiquitous in the environment and is being identified ever more frequently in microbiological laboratories, usually as contaminant. It rarely causes infections of soft tissues and the lungs or systemically.

Aged↗
PubMed1997

Occult malformations of the skull base.

Occult malformations of the skull base are rare anomalies. They are often not detected until they give rise to complications such as meningitis or cerebrospinal fluid rhinorrhea. We used high-resolution computed tomography, fluorescein endoscopy, cisternography, magnetic resonance imaging, and duraplasty to diagnose occult malformations of the skull base in 4 patients. The four patients had had between 4 and 6 attacks of meningitis. Cerebrospinal fluid rhinorrhea was confirmed in 3 cases. The following occult malformations were found: (1) an encephalocele of the glabella/cribriform plate and a meningocele at the petrous bone apex, (2) a meningoencephalocele at the petrous bone apex, (3) dural lesions in the regions foramen rotundum/sphenoid sinus and frontal sinus/cribriform plate, and (4) a dural lesion of the sphenoid sinus. In patients presenting with recurrent meningitis, meningitis with isolation of upper airway pathogens, or cerebrospinal fluid rhinorrhea, modern diagnostic methods should be used to search for dural lesions. Diagnosis of an occult malformation makes it possible to perform the necessary surgical repair and thus prevent the further occurrence of potentially fatal episodes of meningitis.

Adolescent↗
PubMed1997

Comparison of polymerase chain reaction with light microscopy for detection of microsporidia in clinical specimens.

The detection of microsporidial DNA by the polymerase chain reaction (PCR) has been suggested as an alternative or supplement to conventional microscopic methods. However, the relative merits of these techniques remain uncertain. In the present study, clinical specimens of different origin (stool, urine, sputum, nasal discharge, and cerebrospinal fluid) containing four different microsporidial species were blinded after microscopic examination and analyzed by PCR and subsequent restriction fragment length polymorphism (RFLP) to determine the respective species. Thirty-four specimens from 31 patients were evaluated, 16 of which were positive and 18 negative by microscopic examination; PCR detection of microsporidia produced identical results in 82% (28/34) of these specimens. Four samples were microscopically negative, PCR-positive, and two were microscopically positive, PCR-negative. Species determination by RFLP analysis of the amplified product was accurate for all isolates containing Enterocytozoon bieneusi, Encephalitozoon intestinalis, Encephalitozoon hellem, and Encephalitozoon cuniculi compared with microscopic identification of the genus Enterocytozoon or molecular analysis of Encephalitozoon species after in vitro culture. Therefore, PCR-RFLP is useful for the rapid detection and differentiation of microsporidian spores in clinical specimens.

Animals↗
PubMed1997

[Long-term follow-up of fronto-basal dura-plasty].

A safe closure of a dura lesion is necessary on account of the risk of potentially fatal (late) meningitis. 161 duraplasties of the frontal skull base carried out from 1979 to 1994 at the ENT-department Fulda were evaluated in a retrospective study in regard to etiology, operative techniques and results. Duraplasty of the rhinobasis was indicated in 70 cases of rhinobasal trauma, 47 cases after paranasal sinus surgery, 36 cases of tumors and 8 malformations. After an average follow-up time of 6 years the patients were interviewed for postoperative liquorrhea, sinusitis treated with antibiotics and meningitis. As an objective measure to verify the tight closure of the treated CSF-leaks a fluorescein test was performed in 50.9% 6 to 8 weeks after the operation. Duraplasty was successful in more than 96%. The approach and technique to perform a duraplasty have to be chosen individually considering size, location and etiology of the dural defect. In the majority of dural defects in the area of the frontal skull base reconstruction can be carried out now a days via an endonasal approach. By use of allogenic tissue, a mucosal flap from the surrounding area to cover the graft and fibrin clue good results were obtained.

Adolescent↗
PubMed1997

[Early childhood angiofibroma in an unusual site].

Angiofibromas are usually characterized by their occurrences in adolescent males with a typical localization and involvement of the posterior nasal cavity and nasopharynx. Even the suspicion of an extranasopharyngeal angiofibroma or an angiofibroma in young children must be viewed in general with skepticism, although reports of angiofibromas with atypical localizations and manifestations in young children have appeared in the literature. Three cases of this fibro-vascular neoplasm with manifestations in the first decade of life and atypical localizations are presented: (1) an angiofibroma medial to the left lacrimal sac in a 15-month old boy, (2) a right paranasal localization in a 9-year-old boy and (3) an angiofibroma limited to the right sphenoid sinus in a 6-year old boy. In all three cases the neoplasm was resected via an endonasal, micro-endoscopic approach that avoided an external incision. According to the literature and based on our own experiences with typical histological findings in all three cases, the clinician has to be aware that the rare angiofibroma can occur in preadolescent children with atypical localizations. The endonasal surgical approach is without any doubt the least traumatic one and in selected cases allows resection of a circumscribed tumor considering functional and aesthetic aspects.

Angiofibroma↗
PubMed1997

Synthesis and analysis of mixed chlorinated-fluorinated dibenzo-p-dioxins and dibenzofurans and assessment of formation and occurrence of the fluorinated and chlorinated-fluorinated dibenzo-p-dioxins and dibenzofurans.

Various mixtures of chlorinated-fluorinated dibenzodioxins (PCFDD), dibenzofurans (PCFDF) and biphenyls (PCFB) were synthesized. For trace analysis, we compared the behavior of PCFDD/PCFDF and chlorinated congeners in extraction, enrichment and clean-up steps. To establish GC/MS analysis, various columns were tested, temperature programs were optimized and for MS-identification specific masses were selected from the mass spectra. To evaluate the possibility of formation of these compounds in thermal processes, samples from the aluminum-producing industry and products of pyrolysis of chlorofluoro- hydrocarbons (FCKW) on a laboratory scale were analyzed. At present, the most important potential sources of fluorinated or mixed chlorinated-fluorinated dioxins, furans and biphenyls - combustion processes and large scale chemical production - do not cause significant environmental contamination at least in the areas considered. However, in a sample of filter dust from the refining process of aluminum using freon 12 we found high amounts (4.5 g/kg !) of chlorinated and chlorinated-fluorinated aromatic compounds including chlorinated-fluorinated dibenzofurans and biphenyls. Since the FCKW ban in Europe, this procedure was modified in 1992, replacing freon 12 by a mixture of chlorine and argon. The PFDD/PFDF concentration in the fluorophenols was between 0.45 and 120 micrograms/kg. The fluorobenzenes analyzed contained between 15 and 70 mg/kg fluorinated biphenyls.

Benzofurans↗
PubMed1997

Metabolic degradation, inducing potency, and metabolites of fluorinated and chlorinated-fluorinated dibenzodioxins and dibenzofurans.

The metabolic degradation of fluorinated, chlorinated-fluorinated and chlorinated congeners was measured in liver homogenate of NMRI mice. While in the time period between 0 and 240 min no degradation of the 2,3,7,8-TCDD/TCDF could be detected, for all fluorinated congeners a perceptible degradation was found, even for the 2,3,7,8-TFDD. Stepwise chlorination of the 2,3,7,8-fluorinated congeners leads to a decrease of the degradation rate. In the EROD test, the exchange of chloro- with fluorosubstituents in the 2,3,7,8-TCDF leads to a decrease of induction potency. 3,7-Dichloro-2,8-difluorodibenzofuran was about 1/1000th as potent as 2,3,7,8-TCDF, while 2,3,7,8-TFDF was complete inactive. Comparison of the metabolic rates of different TCDD with those of the analogous TFDD demonstrates that the order of enzymatic degradation of different TCDD and the analogous TFDD is identical. The TFDD are degraded slightly faster than the corresponding TCDD. Surprisingly 1,4,6,9-TXDD showed the second slowest metabolic rate of the fluorinated and chlorinated TXDD after 2,3,7,8-TXDD although none of the 2,3,7,8-positions were substituted. Judging from 2,3,7,8-TFDD and 1,7-dichloro-2,8-difluorodibenzofuran the metabolic pathway of fluorinated and chlorinated-fluorinated congeners seem to be comparable to the chlorinated congeners.

Animals↗
PubMed1997

Pneumocystis carinii infection of the conjunctiva in a patient with acquired immune deficiency syndrome.

BACKGROUND: Ocular disease, especially the development of choroidal lesions, is a known extrapulmonary manifestation of Pneumocystis carinii infection in the acquired immune deficiency syndrome (AIDS). To our knowledge, conjunctival involvement due to P. carinii has not been described previously. METHODS: The authors describe a 33-year-old homosexual male with AIDS in whom a large placoid, white lesion developed involving the tarsal conjunctiva of the right upper lid. Conjunctival malignancy was suspected and biopsies and swabs were taken. At this time, the patient had been receiving monthly aerosolized pentamidine prophylaxis for 18 months, and there was neither a history of pneumonia nor any clinical signs of disseminated infection due to P. carinii. RESULTS: Histopathologic examination results of the conjunctival biopsy specimen showed a necrotic, frothy tissue surrounded by activated fibroblasts. Within this material, Gomori methenamine silver stains showed numerous round and cup-like cysts of P. carinii, confirming the diagnosis that had already been obtained by an indirect fluorescent-antibody stain of a conjunctival smear specimen. CONCLUSIONS: The presence of white placoid conjunctival lesions in a patient with AIDS may indicate an infection due to P. carinii. Conjunctival disease due to P. carinii widens the spectrum of AIDS-associated ophthalmic pneumocystosis.

AIDS-Related Opportunistic Infections↗