Biomedical subjects
Publications and source records attributed to J O Gebbers.
BACKGROUND: The term "Castleman's disease" (angiofollicular lymph node hyperplasia) comprises a heterogeneous clinicopathologic entity among lymphoproliferative disorders. CASE REPORT: We present a rare case with retroperitoneal manifestations, and discuss several aspects of diagnosis, differential diagnosis, the clinical course and therapy of the disease. Finally, we summarize the actual knowledge about the pathogenesis of Castleman's disease.
The evaluation of peptide receptors in man is needed not only to discover the physiological target tissues of a given peptide but also to identify diseases with a sufficient receptor overexpression for diagnostic or therapeutic interventions. Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating peptide (PACAP) receptors have been evaluated in human tumors and in their tissues of origin using in vitro receptor autoradiography with 125I-VIP or 125I-acetyl-PACAP-27 in tissue sections. The VIP/PACAP receptor subtypes VPAC1, VPAC2, and PAC1 were evaluated in these tissues by determining the rank order of potencies of VIP and PACAP as well as VPAC1- and VPAC2-selective analogues. The VIP/PACAP receptors expressed in the great majority of the most frequently occurring human tumors, including breast (100% receptor incidence), prostate (100%), pancreas (65%), lung (58%), colon (96%), stomach (54%), liver (49%), and urinary bladder (100%) carcinomas as well as lymphomas (58%) and meningiomas (100%), are predominantly of the VPAC1 type. Their cells or tissues of origin, i.e., hepatocytes, breast lobules and ducts, urothelium, prostate glands, pancreatic ducts, lung acini, gastrointestinal mucosa, and lymphocytes, also predominantly express VPAC1. Leiomyomas predominantly express VPAC2 receptors, whereas paragangliomas, pheochromocytomas, and endometrial carcinomas preferentially express PAC1 receptors. Conversely, VPAC2 receptors are found mainly in smooth muscle (i.e., stomach), in vessels, and in stroma (e.g., of the prostate), whereas PAC1 receptors are present in the adrenal medulla and in some uterine glands. Whereas the very wide distribution of VIP/PACAP receptors in the normal human body is indicative of a key role of these peptides in human physiology, the high VIP/PACAP receptor expression in tumors may represent the molecular basis for clinical applications of VIP/PACAP such as in vivo scintigraphy and radiotherapy of tumors as well as VIP/PACAP analogue treatment for tumor growth inhibition.
OBJECTIVES: The alkaline single cell gel electrophoresis or "comet" assay allows measurement of DNA damage in single cells with a high degree of sensitivity, e.g., for investigations of the effect of environmental agents with DNA-damaging potential. This study aimed to adapt this test to respiratory cells of the human nasal mucosa to examine the genotoxic effect of air pollution (cigarette smoke). STUDY DESIGN: In a prospective study, nasal epithelia of 16 cigarette smokers were examined by the adapted comet assay and the results were correlated with the results of the Papanicolaou-stained nasal cytology, carried out in a blinded fashion. The control group comprised 20 non-smoking men. All subjects under investigation were healthy office workers. METHODS: Nasal epithelia were harvested from the maxilloturbinates. One part of cells was Papanicolaou stained and evaluated by cytopathologists. The comet assay was performed on the other part of the cells. The examiners were blinded to the study and control groups. RESULTS: Among cigarette smokers, a significant correlation between cytopathological cell nucleus changes (metaplasia and dysplasia) and the DNA migration (tail lengths) in the comet assay was found as a sign of DNA damage. This was not found in nonsmoking control persons. CONCLUSIONS: These results confirm the sensitivity of the comet assay and the hypothesis that cell nucleus changes in conventional nasal cytology are associated with DNA damage.
UNLABELLED: The difference between the spectra of potential bacterial pathogens (PBPs) in the nasal vestibule and cavity has not been taken into account in clinical studies. PURPOSE: Since one can anticipate different flora in different kinds of mucosae, the authors compared bacterial species in the vestibule with those of the cavity. SUBJECTS AND METHOD: A total of 534 healthy male clerical workers in a downtown Lucerne office building were examined with fractionated swabs. RESULTS: PBPs, notably Staphylococcus aureus, were found in 412 subjects and surprisingly, differences in flora of the two sites were noted in 130 of them: PBPs were observed in the vestibule and not in the cavity in 85 of the subjects, and in 45 of them, the reverse was true. CONCLUSION: The practical implications of these findings are considerable regarding infection control in patients at increased infection risk.
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Gastric carcinoid tumours are rare neoplasms of neuroendocrine origin. They are believed to grow from enterochrommaffin-like (ECL) cells. Three different types of tumours can be distinguished: type I: hypergastrinaemic, induced by achlorhydria in chronic atrophic gastritis; type II: hypergastrinaemic, associated with Zollinger-Ellison syndrome and multiple endocrine neoplasia syndrome type 1; type III: sporadic. The trophic effect of gastrin on ECL cells is of crucial importance in the pathogenesis and treatment of hypergastrinaemic carcinoids. In these patients, hypergastrinaemia leads to ECL-hyperplasia, -dysplasia and -neoplasia. Hypergastrinaemic carcinoids often follow a very benign course, which makes it possible to avoid surgery, at least in patients at high surgical risk. The management of these three types is discussed.
A 68-year-old patient presenting with non-specific abdominal symptoms was diagnosed as having multiple gastric carcinoid tumours with H. pylori-positive chronic atrophic gastritis and hypergastrinaemia. No metastases were found. As he was inoperable due to comorbidity, conservative management was instituted. The patient was followed for 6 years without signs of tumour progression. He eventually died from an unrelated cause. This case shows that hypergastrinaemic carcinoids may follow a benign course and do not necessitate aggressive surgical management, at least in poor risk patients.
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Virosomal vaccines were prepared by extracting hemagglutinin (HA) and neuraminidase from influenza virus and incorporating it in the membranes of liposomes composed of phosphatidylcholine. Two intranasal spray vaccine series were prepared: one series comprised 7.5 micrograms of HA of each of three strains recommended by the World Health Organization and 1 microgram of Escherichia coli heat-labile toxin (HLT), and the other contained the HA without HLT. In addition, a third vaccine preparation contained 15 micrograms of HA and 2 micrograms of HLT. The parenteral virosomal vaccine contained 15 micrograms of HA without additional adjuvant. The immunogenicity of a single spray vaccination (15 micrograms of HA and 2 micrograms of HLT) was compared with that of two vaccinations (7.5 micrograms of HA with or without 1 microgram of HLT) with an interval of 1 week in 60 healthy working adults. Twenty volunteers received one parenteral virosomal vaccine. Two nasal spray vaccinations with HLT-adjuvanted virosomal influenza vaccine induced a humoral immune response which was comparable to that with a single parenteral vaccination. A significantly higher induction of influenza virus-specific immunoglobulin A was noted in the saliva after two nasal applications. The immune response after a single spray vaccination was significantly lower. It could be shown that the use of HLT as a mucosal adjuvant is necessary to obtain a humoral immune response comparable to that with parenteral vaccination. All vaccines were well tolerated.
Adult-rat-brain tissues display an unusually high resistance to necrosis when serially irradiated with parallel, thin slices of a microplanar (i.e., microscopically thin and macroscopically broad) beam of synchrotron-wiggler-generated, approx. 35-120 keV (median approx. 50 keV) Gd-filtered X rays at skin-entrance absorbed doses of 312 to 5000 Gy per slice. Such microplanar beams were used to irradiate young adult rats bearing right frontocerebral 9L gliosarcomas (approx. 4 mm diameter), through a volume of tissue containing the tumor and contiguous brain tissue, either in a single array or in 2 orthogonally crossed arrays of tissue slices. Each array included 101 parallel microplanar slices, 100 microm center-to-center distance, each slice being approx. 25 microm wide and 12 mm high, with skin-entrance absorbed doses of 312.5 Gy or 625 Gy per slice. Compared with unirradiated controls with a median survival time of 20 days after tumor initiation, the median survival time was extended in irradiated rats by 139 days (625 Gy, crossed arrays), 96 days (312 Gy, crossed arrays) or 24 days (625 Gy, single array). The tumors disappeared in 22 of the 36 irradiated rats, 4/11 even after unidirectional microbeam irradiation. The extent and severity of radiation damage to the normal brain in rats with or without tumor was graded histopathologically. Correlation of those grades with radiation doses shows that loss of tissue structure was confined to beam-crossing regions and that only minor damage was done to zones of the brain irradiated unidirectionally.
Signs and symptoms of neurosarcoidosis are variable and depend on location and size of granulomas. Clinical studies suggest a rate of 5% and autopsy results a rate of more than 25% of central nervous system (CNS) involvement in sarcoidosis. Statistical analysis of 57,789 patients admitted to the Department of Medicine in Lucerne over an 11-year period revealed 51 patients (0.9/1000) with the diagnosis of sarcoidosis. Six of these (12%) had sarcoidosis affecting the CNS. Neurosarcoidosis presented as: leptomeningeal granulomas, cranial nerve palsy, hypothalamic-pituitary syndrome, diabetes insipidus, pareses, paresthesia, pyramidal signs, dementia, urine retention, and asymptomatic granulomas. Neurosarcoidosis has predilections for the base of the brain, cranial nerves (facial nerve palsy is the most common) and meninges, but any part of the CNS may be affected. Therefore, the diagnosis of neurosarcoidosis may be extremely difficult, especially when it occurs as an isolated finding. Positive findings in transbronchial biopsy and lavage may demonstrate asymptomatic pulmonary involvement in as many as 50% of patients with neurosarcoidosis. Angiotensin-converting enzyme levels may be raised in the blood or cerebrospinal fluid in some 50% of cases. Kveim test has a low sensitivity in neurosarcoidosis and thus is of little use. Gallium uptake may demonstrate extracranial granuloma available for biopsy. All these tests, and also computed tomography and magnetic resonance imaging, may be helpful. However, when in selected cases with isolated CNS disease standard investigations are not conclusive, meningeal or cerebral biopsy may be required in order to exclude other causes such as other granulomatous disorders, tumor metastasis, lymphoma, vasculitis, Sjögren syndrome, infection, neurologic disease such as multiple sclerosis, or systemic diseases such as Whipple's disease. CNS involvement in the acute phase of the disease has a favorable prognosis, while chronic courses respond less well to therapy. Treatment is initiated most frequently with corticosteroids (0.5-1 mg/kg body weight/day or pulses of 1 g/day of methylprednisolone in severe cases). Improvement is seen within 1-2 months. Side effects of corticosteroids, aggressive disease or frequent recurrences may require other immunosuppressive drugs (methotrexate, azathioprine, chlorambucil, cyclosporine A). Cerebral irradiation may be successful in some cases when other treatments fail.
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Environmental and preventive medicine are closely related to each other as well as to politics and public awareness. To illustrate this, the example air pollution and the evolution of knowledge thereon are outlined and compared to four other environmental hazards: cigarette smoking, lead, asbestos and electromagnetic fields. The role of the media, of scientists, industry, legislation, and the courts in relation to each of the five hazards are assessed in a table.
AIMS: To determine the pathogenesis of splenic peliosis by further morphological and immunohistochemical examination. METHODS AND RESULTS: Histological, electron microscopic and immunohistochemical examination revealed evidence for an inflammatory genesis of splenic peliosis with destruction of reticular fibres and local deposits of IgG and activated complement C3. CONCLUSION: Our findings indicate that the peliotic lesion in the spleen may be mediated by immune-complex deposits.
Boron-10 (10B) concentrations were measured in 107 surgical samples from 15 patients with glioblastoma multiforme who were infused with 95 atom% 10B-enriched p-boronophenylalanine (BPA) intravenously for 2 h just prior to surgery at doses ranging from 98 to 290 mg BPA/kg body weight. The blood 10B concentration reached a maximum at the end of the infusion (ranging from 9.3 to 26.0 microg 10B/g) and was proportional to the amount of BPA infused. The boron concentrations in excised tumor samples ranged from 2.7 to 41.3 microg 10B/g over the range of administered BPA doses and varied considerably among multiple samples from individual patients and among patients at the same BPA dose. A morphometric index of the density of viable-appearing tumor cells in histological sections obtained from samples adjacent to, and macroscopically similar to, the tumor samples used for boron analysis correlated linearly with the boron concentrations. From that correlation it is estimated that 10B concentrations in glioblastoma tumor cells were over four times greater than concurrent blood 10B concentrations. Thus, in the dose range of 98 to 290 mg BPA/kg, the accumulation of boron in tumor cells is a linear function of BPA dose and the variations observed in boron concentrations of tumor specimens obtained surgically are largely due to differences in the proportion of nontumor tissue (i.e. necrotic tissue, normal brain) present in the samples submitted for boron analysis. The tumor:blood 10B concentration ratio derived from this analysis provides a rationale for estimating the fraction of the radiation dose to viable tumor cells resulting from the boron neutron capture reaction based on measured boron concentrations in the blood at the time of BNCT without the need for analysis of tumor samples from individual patients.