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Biomedical subjects

R Keller

Publications and source records attributed to R Keller.

At least 37 records · Page 2Linked to original sources

Inactivation of Salmonella spp. from secondary and tertiary effluents by UV irradiation.

The aim of this study was to verify the efficiency of UV irradiation in the inactivation of Salmonella spp. in treated wastewater with different levels of turbidity and exposed to increasing doses of UV irradiation. Experiments were carried out in a batch reactor and in a real scale reactor. Salmonellae obtained from clinical samples were seeded into autoclaved wastewater collected from a wastewater treatment plant (WWTP) comprising an association of a UASB reactor followed by three submerged aerated biofilters (BAF) and one tertiary filter. The results showed that salmonellae were not inactivated in effluents from the UASB reactor indicating that the presence of suspended solids was an important obstacle to UV penetration in bacteria. However, UV irradiation was efficient in inactivating Salmonella of effluents from aerated secondary and tertiary biofilm reactors.

Biofilms↗

Switch to quetiapine in antipsychotic agent-related hyperprolactinemia.

Novel antipsychotics (clozapine, risperidone, olanzapine, quetiapine) are effective in treating psychotic symptoms, also in neurological disease. Hyperprolactinemia is a side effect related to antipsychotics that can cause galactorrhea, gynecomastia, amenorrhea, anovulation, impaired spermatogenesis, decreased libido and sexual arousal, impotence, and anorgasmia, consequent to removal of tonic dopaminergic inhibition of prolactin secretion via hypothalamic dopaminergic receptor blockade in the tuberoinfundibolar tract. Hyperprolactinemia occurs more frequently during treatment with risperidone and olanzapine compared with clozapine and quetiapine. The therapeutic algorithm to antipsychotic-relatedhyperprolactinemia is the following: reduction in antipsychotic dose, addition of cabergoline, bromocriptine, amantadine, and/or switch to another antipsychotic. We propose switching to quetiapine in symptomatic hyperprolactinemia related to antipsychotics and describe five cases.

Adolescent↗

Interrelation between ABH blood group 0, Lewis(B) blood group antigen, Helicobacter pylori infection, and occurrence of peptic ulcer.

BACKGROUND: Helicobacter pylori is a human pathogen that causes chronic gastritis and peptic ulcers. Epidemiological studies demonstrated that individuals who are blood group 0 positive or represent non-secretors of their blood group antigens are more likely to develop peptic ulcers. The Lewis(b) blood group antigen has been reported to mediate the attachment of H. pylori to human gastric mucosa. The aim of this study was to examine the interrelation between Le(a-b+) phenotype, blood group 0, H. pylori infection, and peptic ulcer occurrence. PATIENTS AND METHODS: The study population consisted of 330 consecutive patients (185 men, 145 women) referred to endoscopy of the upper gastrointestinal tract for various reasons. AB0(H) blood groups and Lewis(a,b) phenotype were carried out by standard haemagglutination assays. Antibodies (IgG) against H. pylori were determined by a quantitative enzyme-linked immunosorbent assay (ELISA). RESULTS: 49 of the 330 patients (14.8 %) showed duodenal or gastric ulcers with a H. pylori seroprevalence of 87.8 %. The IgG immune response to H. pylori was not dependent on ABH blood group phenotype. There was also no significant association between the secretor status and the presence of H. pylori infection. Secretors, 35/238 (14.7 %), were no more likely to have gastroduodenal ulcer compared with non-secretors, 9/65 (13.8 %). CONCLUSION: Our data show no association between secretor status or specific ABH blood group on the one hand, and H. pylori infection or occurrence of gastroduodenal ulcers on the other. Determination of ABH blood groups or secretor status is, therefore, not a useful tool to characterize the individual risk for gastroduodenal ulcer or to guide any diagnostic procedures.

ABO Blood-Group System↗

Fluorescence endoscopy using a fluorescein-labeled monoclonal antibody against carcinoembryonic antigen in patients with colorectal carcinoma and adenoma.

BACKGROUND AND STUDY AIMS: Various methods of fluorescence excitation and detection have been developed in gastrointestinal endoscopy. This study reports an endoscopic technique using locally applied fluorescein-labeled antibodies for in-vivo detection of colorectal dysplasia and carcinoma. PATIENTS AND METHODS: Fluorescence endoscopy with a fluorescein-labeled monoclonal antibody against carcinoembryonic antigen (CEA) was carried out in 27 patients with colonic polypoid lesions. During conventional colonoscopy, the monoclonal antibody was applied directly onto the mucosal surface. After an incubation time of 10 min, specific fluorescence was visualized with a conventional endoscope whose optical range was increased via two narrow-band filters. RESULTS: Fluorescence in vivo was present in 19 out of 25 carcinomas and in three of eight adenomas. The technique failed in the presence of mucosal ulceration or bleeding. One fluorescence-positive villous adenoma showed high-grade dysplasia, and another fluorescence-positive polypoid lesion was diagnosed as carcinoma in adenoma. Normal-appearing mucosa was fluorescence-negative in all cases. Endoscopic fluorescence significantly correlated with the CEA expression of luminal epithelial cells as determined immunohistochemically (Wilcoxon-Mann-Whitney U-test, P < 0.01). In all cases without ulceration or bleeding, the specificity of fluorescence endoscopy was 100%, the sensitivity was 78.6%, and the accuracy was 89.3%. CONCLUSIONS: Fluorescence endoscopy using fluorescein-labeled monoclonal antibody against CEA was shown to be positive in most cancers and some adenomas. Further and larger studies will be needed to demonstrate the value of this technique for differential diagnosis.

Adenoma↗

Dendritic cells: their significance in health and disease.

Dendritic cells (DCs) represent a heterogeneous population of professional antigen-presenting cells. Precursor cells move via the blood to peripheral tissues. These immature DCs can take up invading pathogens and then rapidly migrate to the draining secondary lymphoid organs. Converted into antigen-presenting mature DCs, these cells are able to prime naive T cells and to initiate an adoptive immune response. The extraordinary functional profile suggests that, under certain preconditions, DCs may represent an ideal vector in the immunotherapy of cancer and infectious diseases

Animals↗

Crustacean hyperglycaemic hormone (CHH)-like peptides and CHH-precursor-related peptides from pericardial organ neurosecretory cells in the shore crab, Carcinus maenas, are putatively spliced and modified products of multiple genes.

About 24 intrinsic neurosecretory neurons within the pericardial organs (POs) of the crab Carcinus maenas produce a novel crustacean hyperglycaemic hormone (CHH)-like peptide (PO-CHH) and two CHH-precursor-related peptides (PO-CPRP I and II) as identified immunochemically and by peptide chemistry. Edman sequencing and MS revealed PO-CHH as a 73 amino acid peptide (8630 Da) with a free C-terminus. PO-CHH and sinus gland CHH (SG-CHH) share an identical N-terminal sequence, positions 1-40, but the remaining sequence, positions 41-73 or 41-72, differs considerably. PO-CHH may have different precursors, as cDNA cloning of PO-derived mRNAs has revealed several similar forms, one exactly encoding the peptide. All PO-CHH cDNAs contain a nucleotide stretch coding for the SG-CHH(41-76) sequence in the 3'-untranslated region (UTR). Cloning of crab testis genomic DNA revealed at least four CHH genes, the structure of which suggest that PO-CHH and SG-CHH arise by alternative splicing of precursors and possibly post-transcriptional modification of PO-CHH. The genes encode four exons, separated by three variable introns, encoding part of a signal peptide (exon I), the remaining signal peptide residues, a CPRP, the PO-CHH(1-40)/SG-CHH(1-40) sequences (exon II), the remaining PO-CHH residues (exon III) and the remaining SG-CHH residues and a 3'-UTR (exon IV). Precursor and gene structures are more closely related to those encoding related insect ion-transport peptides than to penaeid shrimp CHH genes. PO-CHH neither exhibits hyperglycaemic activity in vivo, nor does it inhibit Y-organ ecdysteroid synthesis in vitro. From the morphology of the neurons it seems likely that novel functions remain to be discovered.

Alternative Splicing↗

Development of vitellogenin-ELISA, an in vivo bioassay, and identification of two vitellogenesis-inhibiting hormones of the tiger shrimp Penaeus monodon.

A sandwich enzyme-linked immunosorbent assay (ELISA) for the quantification of vitellogenin in the hemolymph of Penaeus monodon is reported. Lipovitellin from the mature ovary was purified using hydroxylapatite column chromatography and used as the standard protein, which was serially diluted from 3336 to 6.51 microg and gave a linear plot. Sensitivity results showed ELISA was insensitive to samples that did not contain vitellogenin or lipovitellin. Specificity results showed the degree of the discrimination of the assay between positive samples (having vitellogenin or lipovitellin) and negative samples (devoid of vitellogenin or lipovitellin). Reproducibility studies showed that the intraassay coefficient of variation was 5.1% (n = 11) and the interassay coefficient of variation was 5.15% (n = 13). Separation of X-organ sinus gland peptides using a reversed phase column gave a total of 37 fractions. Two fractions were found to reduce the hemolymph vitellogenin concentration in a time-dependent manner and could be identified as vitellogenesis-inhibiting hormones I and II.

Journal Article↗

Diagnostic value of DNA image cytometry in ulcerative colitis.

The increased risk of colorectal cancer in patients with extensive, long-standing ulcerative colitis is well established. The interpretation of dysplasia as the common precursor lesion of colorectal cancer in ulcerative colitis is, however, subject to inter- and intraobserver variation. The histologic diagnosis is particularly difficult in the presence of acute inflammation. Therefore, the analysis of ploidy patterns might be a more objective diagnostic tool. In the present study, the correlation of ploidy and dysplasia of the colonic mucosa was evaluated in the absence and presence of inflammation. Image cytometry was performed on 561 fixed, paraffin-embedded tissue specimens from 67 patients with ulcerative colitis. Twenty patients had long-standing and extensive disease, including eight patients in whom the colitis was associated with colorectal cancer. Dysplasia was only found in patients with long-standing colitis or with colorectal cancer and was significantly more often diagnosed in the case of concomitant inflammation. On the other hand, aneuploid patterns were shown to occur independent of inflammatory activity. Aneuploidy was present in all colorectal carcinomas associated with ulcerative colitis and in 46.2% of specimens with dysplasia. Moreover, aneuploidy was detectable in four of 12 samples with low-grade dysplasia as well as in one case devoid of any dysplastic alteration. Ulcerative colitis patients with low-grade dysplasia plus aneuploidy probably represent a subgroup that might be at higher risk of developing colorectal cancer than patients with low-grade dysplasia alone. All in all, image cytometry analysis might be instrumental in identifying neoplastic lesions even in cases of increased inflammatory activity or regenerative change.

Adolescent↗

Mesalazine 4 g daily given as prolonged-release granules twice daily and four times daily is at least as effective as prolonged-release tablets four times daily in patients with ulcerative colitis.

BACKGROUND: High doses of mesalazine usually result in an inconvenient dosage schedule and reduced compliance. The goal of this trial was to compare the effects of mesalazine 4 g daily given as prolonged-release granules in packets of 1 g with that of prolonged-release tablets of 0.5 g. METHODS: Two hundred twenty-seven patients with mild-to-moderate ulcerative colitis were randomized to treatment with two packets twice daily (Gr-b.i.d.), 1 packet four times daily (Gr-q.i.d.) or 2 tablets four times daily (Ta-q.i.d.) for 8 weeks. A disease activity index (ulcerative colitis disease activity index: UC-DAI) was calculated, and the granules were defined as noninferior to the tablets if the lower limit of the 95% CI for the differences was more than -1 UC-DAI score unit. RESULTS: Noninferiority of the granules compared with the tablets was demonstrated. The mean improvement in the UC-DAI in the treatment groups Gr-b.i.d., Gr-q.i.d., and Ta-q.i.d. were 3.2, 2.9, and 2.4, respectively; the proportion of complete responders in the three groups 39%, 37%, and 31%, respectively. There were no differences in side effects. CONCLUSION: Mesalazine 4 g daily given as prolonged-release granules twice and four times daily is at least as effective as prolonged-release tablets four times daily in patients with mild to moderate ulcerative colitis. The patients preferred the twice daily dosing.

Adolescent↗

Effects of serotonin and fluoxetine on blood glucose regulation in two decapod species.

One of the best known crustacean hormones is the crustacean hyperglycemic hormone (CHH). However, the mechanisms involved in hormone release in these animals are poorly understood, and thus constitute the central objective of the present study. Different groups of crustaceans belonging to diverse taxa (Chasmagnathus granulata, a grapsid crab and Orconectes limosus, an astacid) were injected with serotonin, fluoxetine, or a mixture of both, and glycemic values (C. granulata and O. limosus) and CHH levels (O. limosus) were determined after 2 h in either submerged animals or animals exposed to atmospheric air. Both serotonin and fluoxetine caused significant hyperglycemia (P<0.05) after injection into the blood sinus of the two species, an effect enhanced after exposure to atmospheric air. In C. granulata blood glucose increased from 6.1 to 43.3 and 11.4 mg/100 ml in submerged animals and from 5.7 to 55.2 and 22.5 mg/100 ml in air-exposed animals after treatment with serotonin and fluoxetine, respectively. In O. limosus the increases were from 1.2 to 59.7 and 135.2 mg/100 ml in submerged animals and from 2.5 to 200.3 and 193.6 mg/100 ml in air-exposed animals after treatment with serotonin and fluoxetine, respectively. Serotonin and fluoxetine also caused a significant increase in the circulating levels of CHH in O. limosus, from 11.9 to 43 and 45.7 fmol/ml in submerged animals and from 13.2 to 32.6 and 45.7 fmol/ml in air-exposed animals, respectively, thus confirming their action as neuroregulators in these invertebrates.

Animals↗

HHV-8 infection in patients with AIDS-related Kaposi's sarcoma in Brazil.

The aims of the present study were to determine the prevalence of human herpesvirus type 8 (HHV-8) in HIV-positive Brazilian patients with (HIV+/KS+) and without Kaposi's sarcoma (HIV+/KS-) using PCR and immunofluorescence assays, to assess its association with KS disease, to evaluate the performance of these tests in detecting HHV-8 infection, and to investigate the association between anti-HHV-8 antibody titers, CD4 counts and staging of KS disease. Blood samples from 66 patients, 39 HIV+/KS+ and 27 HIV+/KS-, were analyzed for HHV-8 viremia in peripheral blood mononuclear cells by PCR and HHV-8 antigenemia for latent and lytic infection by immunofluorescence assay. Positive samples for latent nuclear HHV-8 antigen (LNA) antibodies were titrated out from 1/100 to (1/4)09,600 dilution. Clinical information was collected from medical records and risk behavior was assessed through an interview. HHV-8 DNA sequences were detected by PCR in 74.3% of KS+ patients and in 3.7% of KS- patients. Serological assays were similar in detecting anti-LNA antibodies and anti-lytic antigens in sera from KS+ patients (79.5%) and KS- patients (18.5%). HHV-8 was associated with KS whatever the method used, i.e., PCR (odds ratio (OR) = 7.4, 95% confidence interval (CI) = 2.16-25.61) or anti-LNA and anti-lytic antibodies (OR = 17.0, 95%CI = 4.91-59.14). Among KS+ patients, HHV-8 titration levels correlated positively with CD4 counts (rho 0.48, P = 0.02), but not with KS staging. HHV-8 is involved in the development of KS in different geographic areas worldwide, as it is in Brazil, where HHV-8 is more frequent among HIV+ patients. KS severity was associated with immunodeficiency, but no correlation was found between HHV-8 antibody titers and KS staging.

AIDS-Related Opportunistic Infections↗

Infection and disease among household contacts of patients with multidrug-resistant tuberculosis.

SETTING: Urban public teaching and referral hospital in Espirito Santo, Brazil. OBJECTIVE: To assess whether rates of infection and progression to active tuberculosis (TB) differed between household contacts of patients with multidrug-resistant (MDR) and drug susceptible (DS) pulmonary tuberculosis. DESIGN: Household contacts were assessed for evidence of TB infection and disease by purified protein derivative (PPD) skin testing, physical examination, chest X-ray, and sputum smear and culture. RESULTS: Among 133 close contacts of patients with MDR-TB, 44% were PPD-positive (> or =10 mm) compared to 37% of 231 contacts of the DS-TB cases (P = 0.18, chi2 test, OR 1.2, 95%CI 0.8-2). In a multivariate logistic regression analysis, after allowance for between-household variation in PPD responses, PPD positivity among household contacts of patients with MDR-TB remained comparable to PPD positivity in contacts of patients with DS-TB (OR 2.1, 95%CI 0.7-6.5). Respectively six (4%) and 11 (4%) contacts of the MDR- and DS-TB cases were found to have active TB at the time of initial evaluation or during follow-up (P = 0.78, chi2 test). Five of six contacts of MDR-TB cases and nine of nine contacts of DS-TB cases who developed TB, and for whom drug susceptibility test results were available, had the same bacterial susceptibility profiles as their index cases. DNA fingerprinting analysis of Mycobacterium tuberculosis isolates was identical between household contacts with active TB and the index MDR or DS-TB case for all 14 pairs compared. CONCLUSION: Our data suggest that the prevalence of tuberculous infection and progression to active TB among household contacts exposed to DS and MDR-TB cases is comparable, despite a longer duration of exposure of contacts to the index case in patients with MDR-TB.

Adolescent↗

Cells remain competent to respond to mesoderm-inducing signals present during gastrulation in Xenopus laevis.

During gastrulation, the vertebrate embryo is patterned and shaped by complex signaling pathways and morphogenetic movements. One of the first regions defined during gastrulation is the prospective notochord, which exhibits specific cell behaviors that drive the extension of the embryonic axis. To examine the signals involved in notochord formation in Xenopus laevis and the competence of cells to respond to these signals, we performed cell transplantation experiments during gastrulation. Labeled cells from the prospective notochord, somitic mesoderm, ventrolateral mesoderm, neural ectoderm, and epidermis, between stages 9 (pregastrulation) and 12 (late gastrulation), were grafted into the prospective notochord region of the early gastrula. We show that cells from each region are competent to respond to notochord-inducing signals and differentiate into notochordal tissue. Cells from the prospective neural ectoderm are the most responsive to notochord-inducing signals, whereas cells from the ventrolateral and epidermal regions are the least responsive. We show that at the end of gastrulation, while transplanted cells lose their competence to form notochord, they remain competent to form somites. These results demonstrate that at the end of gastrulation cell fates are not restricted within germ layers. To determine whether notochord-inducing signals are present throughout gastrulation, grafts were made into progressively older host embryos. We found that regardless of the age of the host, grafted cells from each region give rise to notochordal tissue. This indicates that notochord-inducing signals are present throughout gastrulation and that these signals overlap with somite-inducing signals at the end of gastrulation. We conclude that it is the change of competence that restricts cells to specific tissues rather than the regulation of the inducing signals.

Animals↗

Monopolar protrusive activity: a new morphogenic cell behavior in the neural plate dependent on vertical interactions with the mesoderm in Xenopus.

We compared the type and patterning of morphogenic cell behaviors driving convergent extension of the Xenopus neural plate in the presence and absence of persistent vertical signals from the mesoderm by videorecording explants of deep neural tissue with involuted mesoderm attached and of deep neural tissue alone. In deep neural-over-mesoderm explants, neural plate cells express monopolar medially directed motility and notoplate cells express randomly oriented motility, two new morphogenic cell behaviors. In contrast, in deep neural explants (without notoplate), all cells express bipolar mediolateral cell motility. Deep neural-over-mesoderm and deep neural explants also differ in degree of neighbor exchange during mediolateral cell intercalation. In deep neural-over-mesoderm explants, cells intercalate conservatively, whereas in deep neural explants cells intercalate more promiscuously. Last, in both deep neural-over-mesoderm and deep neural explants, morphogenic cell behaviors differentiate in an anterior-to-posterior and lateral-to-medial progression. However, in deep neural-over-mesoderm explants, morphogenic behaviors first differentiate in intervals along the anteroposterior axis, whereas in deep neural explants, morphogenic behaviors differentiate continuously from the anterior end of the tissue posteriorly. These results describe new morphogenic cell behaviors driving neural convergent extension and also define roles for signals from the mesoderm, up to and beyond late gastrulation, in patterning these cell behaviors.

Animals↗

Mechanisms of convergence and extension by cell intercalation.

The cells of many embryonic tissues actively narrow in one dimension (convergence) and lengthen in the perpendicular dimension (extension). Convergence and extension are ubiquitous and important tissue movements in metazoan morphogenesis. In vertebrates, the dorsal axial and paraxial mesodermal tissues, the notochordal and somitic mesoderm, converge and extend. In amphibians as well as a number of other organisms where these movements appear, they occur by mediolateral cell intercalation, the rearrangement of cells along the mediolateral axis to produce an array that is narrower in this axis and longer in the anteroposterior axis. In amphibians, mesodermal cell intercalation is driven by bipolar, mediolaterally directed protrusive activity, which appears to exert traction on adjacent cells and pulls the cells between one another. In addition, the notochordal-somitic boundary functions in convergence and extension by 'capturing' notochordal cells as they contact the boundary, thus elongating the boundary. The prospective neural tissue also actively converges and extends parallel with the mesoderm. In contrast to the mesoderm, cell intercalation in the neural plate normally occurs by monopolar protrusive activity directed medially, towards the midline notoplate-floor-plate region. In contrast, the notoplate-floor-plate region appears to converge and extend by adhering to and being towed by or perhaps migrating on the underlying notochord. Converging and extending mesoderm stiffens by a factor of three or four and exerts up to 0.6 microN force. Therefore, active, force-producing convergent extension, the mechanism of cell intercalation, requires a mechanism to actively pull cells between one another while maintaining a tissue stiffness sufficient to push with a substantial force. Based on the evidence thus far, a cell-cell traction model of intercalation is described. The essential elements of such a morphogenic machine appear to be (i) bipolar, mediolaterally orientated or monopolar, medially directed protrusive activity; (ii) this protrusive activity results in mediolaterally orientated or medially directed traction of cells on one another; (iii) tractive protrusions are confined to the ends of the cells; (iv) a mechanically stable cell cortex over the bulk of the cell body which serves as a movable substratum for the orientated or directed cell traction. The implications of this model for cell adhesion, regulation of cell motility and cell polarity, and cell and tissue biomechanics are discussed.

Amphibians↗

The origin and morphogenesis of amphibian somites.

The origin and development of the amphibian somitic mesoderm is summarized and reviewed with the goal of identifying issues most profitably pursued in these organisms. The location of the prospective somitic mesoderm as well as the cell movements bringing this tissue into its definitive position varies among amphibians. These variations have implications for the tissue interactions patterning the embryo, the design of the gastrulation movements, the role of the somitic mesoderm in early patterning and morphogenic processes, and the nature of the developmental pathway leading to somites. The presegmentation morphogenesis, the process of segmentation, and the subsequent, postsegmentation morphogenesis of the somitic mesoderm also varies considerably among amphibians. Although segmentation in amphibians shares what may be highly conserved and general patterning mechanisms with other vertebrates, the somitic developmental pathway as a whole is not conservative and has been capable of accommodating the use of a number of quite different morphogenic processes, all leading to very similar ends. The major challenges in studying amphibian somitogenesis are to develop molecular markers for major components of the somite, to determine the derivatives of the somite with better cell tracing experiments, and learning to work with the small dermatomal and sclerotomal cell populations found in most species. A potential advantage is that the diversity of somitogenesis among the amphibians makes this group ideal for studying the evolution of developmental processes. In addition, many amphibians allow direct observation of somitogenesis with great resolution and permit biomechanical analysis of tissues participating in morphogenesis, thus making it possible to analyze cellular mechanisms of morphogenesis in ways not possible in most other systems.

Amphibians↗

[Spontaneous lysis of pulmonary aspergillosis: "Aspergillus destroyed by Actinomyces"].

A 79 years old patient developed a large pulmonary aspergilloma in the cavities of his right upper lobe after postinfarctional pneumonia with local abscess formation. The clinical follow-up was characterized by recurrent hemoptysis resulting in marked anemia as well as by a continuous growth of the mycetoma. Suddenly a purulent gangrene of the whole upper lobe occurred infected by actinomyces israelii and staphylococcus but not aspergillus as it could be demonstrated in specimens from repeated transthoracic needle aspirations. After percutaneously inserted chest-tube drainage during 30 days the upper lobe cavity cleared up and the previously impressive aspergilloma had disappeared completely, however, the serum precipitins from aspergillus fumigatus still remained positive. After a course of several months without further pulmonary complications the patient finally died from a ruptured aortic aneurysm. It is suggested, that the spontaneous lysis of the aspergilloma was due to a deprivation of it' nutritive basis by the infected pulmonary tissue. A similar mechanism may also account for a sometimes successful treatment of pulmonary aspergilloma after injection of an amphotericin containing paste as a novel therapeutic strategy which is recommended in the case of patient's inoperable conditions.

Actinomycosis↗

[Bilateral malfunction of peripheral vestibular organs. Observations of 20 cases of Dandy syndrome].

BACKGROUND: Dandy's Syndrome initially provokes dizziness and vertigo. Later on patients suffer from motion unsteadiness especially in dark surroundings and from oscillopsies. Gentamicin is ototoxic mostly for the vestibular part of the inner ear, and it is nephrotoxic. It may cause transitory renal dysfunction. Chronic or acute renal insufficiencies inhibit gentamicin clearance. PATIENTS: Among 20 cases we found 15 who had previously been treated with aminoglycosides (13 with gentamicin and two with streptomycin). Ten of our patients showed symptoms of preexistant chronic nephrosis or of transitory renal insufficiency caused by gentamicin therapy. In all 13 cases, peripheral vestibular function was destroyed or severely damaged by antibiotic. The same patients had no hearing loss. CONCLUSIONS: The different reactions of the cochlear and the vestibular end organs support the theoretical basis for transtympanic gentamicin treatment of Menière's disease.--Other reasons for Dandy's Syndrome were bilateral Menière's disease, skull fractures, and bilateral vestibular disorders.

Anti-Bacterial Agents↗