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Biomedical subjects

A Valentin

Publications and source records attributed to A Valentin.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Cryptosporidiosis in adders (Pituiophis melanoleucus sayi)].

Infection of snakes with cryptosporidia is known to occur as hypertrophic gastritis associated with postprandial regurgitation. This is a report of a severe and fatal intestinal cryptosporidiosis in a group of snakes (Pituophis melanoleucus sayi) kept at a zoological garden. The clinical and pathological findings are described and discussed in this paper. Pathohistologically fibrinous, diphtheroid and necrotizing enteritides were diagnosed. Histological examination was completed by electron microscopy. Transmission electron microscopic examination revealed numerous cryptosporidia in close contact to the luminal surface of the intestinal epithelial cells. Different cryptosporidial stages developing in parasitophorous vacuoles occurred. By scanning electron microscopy the superficial localisation of the cryptosporidia in the damaged brush border of the intestinal epithelial cells was demonstrated. In addition, the ultrastructural examination of the small intestine of three animals revealed adenovirus-like particles.

Animals↗
PubMed1997

Genital myiasis (Wohlfahrtiosis) in camel herds of Mongolia.

Genital infestations caused by Wohlfahrtia magnifica (Schiner, 1862) has been reported as being a common problem encountered in female camels in the Gobi desert. Thus, a field investigation to establish the prevalence of wohlfarthiosis in camel herds in the eastern Gobi district was carried out between May and July 1994. The objectives of the study were to establish the relevance of genital myiasis, and to describe the disease patterns, clinical course and pathomorphological changes associated with it. The field study was designed to suit the specific ecological, infrastructural and logistic conditions. Two cross-sectional samples were taken from 45 selected herds in six different areas of the Chatanbulag Sumon to obtain data on herd structure, age distribution, and the breeding history of infested female animals. Post partum events and previous occurrence of genital myiasis were recorded by use of a standardised questionnaire. Clinically infested animals were first detected visually. All camels to be investigated further were subsequently immobilised using ropes and the genitals were examined for tissue lesions and the presence of larvae. Examination of 1676 Bactrian camels from 45 selected herds in six different areas of the Chatanbulag Sumon in the Eastern Gobi district, Mongolia, led to an estimate of Wohlfahrtia magnifica infestation rates between 8-10%. Most myiasis cases were found in older females (> 4 yr), younger animals were infested at a lower rate. Highest prevalence rates were discovered during June and July, highest levels of infestation occurred in the Aman Us Chudak region with infestation rates up to 15%.

Age Factors↗
PubMed1997

Transcranial Doppler for early identification of potential organ transplant donors.

BACKGROUND: Encouraging results in transplant medicine create a growing demand for organ transplant donors. Transcranial Doppler (TCD) has been used by several investigators to assess arrest of the cerebral circulation in brain dead patients. We report on TCD as a monitoring tool for early identification of potential organ transplant donors. DESIGN: A prospective clinical study. SETTING: Intensive care unit (ICU) of a 900-bed community hospital (primary and tertiary care center) in Vienna, Austria. SUBJECTS AND METHODS: All patients with acute intracranial lesions admitted to our intensive care unit underwent TCD examination at least once daily. In patients with Glasgow Coma Scores < 7, TCD waveforms with high resistance profiles unchanged by therapeutic attempts to lower intracranial pressure indicated the need for repeated TCD up to four times a day. TCD waveform abnormality consisting of absent or reversed diastolic flow or small early systolic spikes in at least two intracranial arteries was considered to constitute intracranial circulatory arrest. Brain death was confirmed by clinical criteria, an isoelectric electroencephalography (EEG) or non filling of the intracerebral arteries on arteriography. RESULTS: From January 1994 to July 1996 we identified 11 comatose patients as potential organ transplant donors with typical TCD findings indicating intracranial circulatory arrest. Diagnosis was subarachnoid hemorrhage in 7 and intracerebral hemorrhage in 4 patients. Brain death diagnosis according to the criteria of Austrian law was initiated immediately after the TCD findings suggested intracranial circulatory arrest. Confirmation of brain death was obtained by clinical criteria and either EEG (6 patients) or cerebral angiography (5 patients). CONCLUSION: TCD examinations on a daily routine basis offer a noninvasive monitoring method for early assessment of intracranial circulatory arrest. TCD enables quick identification and further diagnosis of candidates for organ transplant donation.

Adult↗
PubMed1997

[Definition and evaluation of a documentation standard for intensive care medicine: the ASDI(Working Group for Standardization of a documentation system for Intensive care medicine) pilot project].

OBJECTIVES: A comparison of data from different intensive care units (ICUs) needs standardized documentation. In this study the ASDI documentation standard for intensive care was tested in clinical practice. Goal of the study was to evaluate parameters and functionality required for a national, interdisciplinary documentation system for intensive care. DESIGN: 13 ICUs participated in a 4-week trial using the provided program for documentation of all admitted patients during the observation period. In addition, a questionnaire was distributed to the unit coordinators. RESULTS: 376 patients were documented in 1591 patient days. Valid SAPS II scores were found in only 29% of the discharged patients (39.1 +/- 15.5 points). Time needed for data entry exceeded preset limits (ten minutes per patient and day) in 38% of the cases. All participants affirmed the necessity of a documentation standard for intensive care, giving quality control and cost analysis as the most important reasons. CONCLUSION: The ASDI data set fitted existing needs very closely. Only 7 out of 122 parameters (5.7%) were found to be superfluous and thus removed. Measures to reduce documentation effort to the default limits were a) a new, date orientated concept for manual recording, b) rede-sign of the user interface with new, user friendly data entry possibilities, and c) the integration of statistical analysis and reports in the documentation system. The revised data set represents a broad-based consensus, which seems to be well-suited as foundation for the national quality assurance program.

Adolescent↗
PubMed1997

Antisymmetric Amino-Wagging Band of Hydrazine up to K' = 13 Levels

A newly recorded high-resolution infrared spectrum of hydrazine has been studied in the 729-1198 cm-1 region (the nu12 antisymmetric wagging band) with a resolution of 0.002 cm-1. About 1350 transitions with K' from 7 to 13 have been newly assigned and about 2350 transitions with lower values of K' reanalyzed with the improved precision. The effective parameters have been calculated separately for each value of K' using the Hougen-Ohashi hamiltonian for hydrazine. The extended assignment completes the analysis of the nu12 band of hydrazine. Copyright 1997 Academic Press. Copyright 1997Academic Press

Journal Article↗
PubMed1997

Demonstration of Helicobacter pylori-like organisms in the gastric mucosa of captive exotic carnivores.

Samples of gastric tissue from the cardiac, fundic and pyloric region of 30 carnivores comprising 12 tigers (Panthera tigris), 10 lions (Panthera leo), three pumas (Felis concolor), two leopards (Panthera pardus), one serval (Felis serval), one wolf (Canis lupus) and one hyena (Crocuta crocuta) kept at German zoological gardens were subjected to histopathological and immunohistochemical examination. Selected tissue specimens of 12 animals were examined also by electron microscopy. The purpose of this study was to determine the prevalence of Helicobacter-like organisms in carnivores and to record infection rates, degree of colonization and associated histopathological changes. Three morphologically different types of spiral-shaped bacteria were demonstrated. A Helicobacter pylori-like organism (HPLO) was found in 42% of the tigers and 90% of the lions examined. Large Helicobacter-like organisms (HLOs) were identified in three pumas, one serval, one hyena and in three lions (in the latter, in coexistence with HPLOs). A third organism with a spiral periplasmic fibril (Helicobacter felis-like) was demonstrated in a wolf. The most striking histopathological finding associated with HPLO and HLO colonization was the formation of lymphoid follicles in the mucosa. Additional lymphoplasmacytic and neutrophilic infiltrates in the gastric mucosa were found in a number of tigers and lions infected with HPLOs, but none in the other carnivores infected with HLOs. From these results it is concluded that gastric bacteria similar or identical with H. pylori may also be an important cause of chronic gastritis in tigers and lions.

Animals↗
PubMed1997

Local anesthesia for arthroscopic surgery of the ankle using pethidine or prilocaine.

Investigation of the intraoperative and postoperative pain-reducing effect of pethidine (meperidine) as compared with local anesthetics given into the ankle joint was performed, in a comparative and double-blind fashion, in 20 patients subjected to arthroscopy of the ankle, diagnostic and surgical procedures. These patients were randomly assigned to one of two groups. Group A consisted of 10 patients receiving prilocaine 5% with adrenaline and the patients of group B received pethidine 5% with adrenaline intraarticularly. During arthroscopy, the patients reported on pain and discomfort using visual analog scales. Ratings did not differ between the two groups, but six patients would not have chosen the local anesthetic technique again. Postoperatively, all patients rated their pain and discomfort at rest and at movement (1, 2, 3, 5, 6, 8, and 24 hours and at three times during 2 following days). No differences were found between the two groups, except for pain at rest through the whole observation period when significant lower values for pethidine. There were no differences in use of analgesics between the two groups. The current study indicates that pethidine is a potential alternative to prilocaine in arthroscopy of the ankle.

Adult↗
PubMed1997

Analgesia following arthroscopy--a comparison of intra-articular morphine, pethidine and fentanyl.

It has recently been reported that morphine given in low doses intra-articularly can produce significant analgesia in patients undergoing arthroscopic knee joint surgery. Data are lacking on the effect of other opioids using a local approach for drug delivery. We studied the analgesic effect of intra-articular opioids in 70 patients, divided into 7 groups, subjected to arthroscopic knee surgery in general anesthesia. The dimension of the study was based on a power of 0.8 to detect a 25% difference in pain intensity between those receiving opioids locally versus systemically (alpha = 0.05 and beta = 0.20). Following surgery, but before terminating anesthesia, the patients received one of the following combinations: 1 mg morphine intra-articularly (i.art.) + saline intramuscularly (i.m.), 10 mg pethidine i.art + saline i.m., or 10 micrograms fentanyl i.art + saline i.m. In three additional groups the three opioids were given i.m. and saline given i.art. An additional control group received saline i.art. + i.m. We did not find any significant difference between the groups considering postoperative pain intensity, need for analgesics or considering time to standing/walking or to discharge, analysing each opioid independently. There was, however, a tendency for pethidine i.art. to produce the lowest pain scores both at rest and during movement (P = 0.06). If analysing the results with regards to if opioids were given intra-articularly or systemically, not considering the type of opioid given, we did however, find a significantly lower total sum of pain scores at movement following local administration (P < 0.05). No specific side-effects were detected. We conclude that pethidine given intra-articularly merits further investigation with respect to postoperative analgesia following the activation of peripheral opioid mechanisms.

Acetaminophen↗
PubMed1997

Reduced viral load and lack of CD4 depletion in SCID-hu mice infected with Rev-independent clones of human immunodeficiency virus type 1.

The posttranscriptional control element CTE of the simian type D retrovirus has been shown to support replication of Rev-Rev-responsive-element (RRE)-deficient molecular clones of human immunodeficiency virus type 1 (HIV-1). Upon infection of peripheral blood mononuclear cells in vitro, these CTE-containing Rev-independent viruses that are nef+ or nef-minus showed lower replicative capacity and infectivity than the wild-type HIV-1. We studied the effects of Rev-RRE replacement by the CTE on HIV-1 expression with SCID-hu mice. The nef+ and nef-minus Rev-independent viruses established infection with kinetics slower than that of the nef-minus NL4-3. Most importantly, no depletion of CD4-bearing thymocytes was observed after 6 weeks for mice infected with these Rev-independent viruses. This is in contrast to the infection with both wild-type and nef-minus viruses, which led to varying depletion of thymocytes. These data suggest an attenuated phenotype for growth and cytotoxicity of the Rev-independent HIV-1 clones in SCID-hu mice, independent of the presence of Nef. The mutant viruses, which have the essential Rev-RRE regulatory system eliminated, display a distinct phenotype not previously observed with HIV mutant viruses having deletions of accessory genes. Therefore, replacement of the Rev-RRE regulatory axis may generate viruses with altered biological properties in vivo.

Animals↗
PubMed1996

Comparative resistance of Candida albicans clinical isolates to fluconazole and itraconazole in vitro and in vivo in a murine model.

Relationships between azole susceptibility and in vivo response to antifungal therapy in a murine model of candidiasis were investigated for Candida albicans isolates sampled from human immunodeficiency virus type 1-positive patients with oropharyngeal candidiasis. The susceptibilities of seven clinical isolates and two reference strains to fluconazole (FCZ) and itraconazole (ITZ) were determined in vitro by the broth microdilution method. Four isolates were resistant to FCZ and ITZ, two were susceptible to both azoles, and three were resistant to FCZ and susceptible to ITZ (dissociated resistance). CD1 mice were inoculated with each isolate and treated with either FCZ or ITZ (drug regimen, 5 mg/kg of body weight twice daily for 5 days). Quantitative cultures of kidneys were performed at the end of the treatment. On the other hand, the survival rates of the mice were followed daily. These two parameters were clearly correlated with in vitro susceptibility. Thus, the phenomenon of a dissociation of resistance to FCZ and ITZ may be found in vivo as well as in vitro.

Animals↗
PubMed1996

The posttranscriptional control element of the simian retrovirus type 1 forms an extensive RNA secondary structure necessary for its function.

It was previously shown that a 240-nucleotide (nt) RNA element (cis-acting transactivation element [CTE]) located between the env gene and the 3' long terminal repeat of simian retrovirus type 1 (SRV-1) can functionally replace posttranscriptional activation directed by Rev and the Rev-responsive element (RRE) when inserted into a Rev- and RRE-deficient molecular clone of human immunodeficiency virus type 1, resulting in efficient virus replication. Here, we analyze the molecular and structural requirements for function of this RNA element. Deletion mutagenesis demonstrated that the core element spans 173 nt. SRV-2 and Mason-Pfizer monkey virus have highly homologous elements, which function similarly when inserted into the Rev/RRE-deficient human immunodeficiency virus type 1. Computer prediction indicated that the core CTEs of all three viruses have similar extensive secondary structures. Mutagenesis of the SRV-1 CTE revealed that both sequence and secondary structure are essential for function. Nuclease probing of the SRV-1 CTE further supported the genetic analysis and confirmed the predicted structural features of the RNA element. Sequence analysis of the 240-nt SRV-1 CTE, after continuous long-term propagation of the Rev-independent viruses, revealed that the genetically defined core element remained unchanged, while regions outside the core CTE underwent deletions or duplications. These data further support our in vitro mutagenesis data and demonstrate the importance of the sequence and structure of the SRV-1 CTE for appropriate function.

Base Sequence↗
PubMed1996

Sex-related differences in acetazolamide-induced cerebral vasomotor reactivity.

BACKGROUND AND PURPOSE: Cerebral vasomotor reactivity can easily be assessed reliably by measuring vasodilatory response to acetazolamide by transcranial Doppler sonography. The aim of this study was to confirm the hypothesis that female sex is associated with an increased cerebrovascular flow reserve. METHODS: Blood flow velocity of the middle cerebral artery was measured by transcranial Doppler sonography in 36 healthy sex- and age-matched subjects. After the initial blood flow velocities were recorded, the subjects received 14.3 mg/kg body wt acetazolamide, ie, 1 g/70 kg, intravenously. The measurements were repeatedly performed at 5-minute intervals starting 10 minutes after injection and lasting for 30 minutes. The highest measured flow velocities were used for further analysis. RESULTS: In both groups mean blood flow velocity increased significantly after acetazolamide (women, from 60.2 +/- 12.5 to 89.9 +/- 14.4 cm/s, P < .006; men, from 54.5 +/- 18.8 to 75.7 +/- 24.5 cm/s, P < .02). The difference in mean blood flow velocity after acetazolamide between groups of women and men was statistically significant (P < .02). CONCLUSIONS: Female subjects show an increased vasodilatory response to the acetazolamide test compared with men.

Acceleration↗
PubMed1996

In vitro antimalarial activity of vegetal extracts used in West African traditional medicine.

Among strategies for the development of new antimalarials, a study of plants traditionally used in Africa against malaria has been pursued. Extracts obtained from the plants Azadirachta indica, Cinnamonum camphora, Lippia multiflora, Vernonia colorata, Guiera senegalensis, Combretum micranthum, and Ximenia americana, commonly used in Cote d'Ivoire by native healers for the treatment of malaria, were tested on two strains of Plasmodium falciparum: FcB1-Colombia (chloroquine-resistant) and F32-Tanzania (chloroquine-sensitive). Extracts were obtained after infusion and decoction, both techniques being used by most native healers. The antimalarial activities of the extracts were tested first by parasite 3H-hypoxanthine incorporation and second by visual evaluation of the activities of plant extracts on thin blood smears, which also permitted the determination of parasitic stages and parasite alteration. Among the seven plants tested, some had an apparent inhibitory effect on P. falciparum growth in vitro, while other seemed to be less efficient.

Animals↗
PubMed1995

Large scale survey of bovine babesiosis due to Babesia divergens in France.

Data on the epidemiology of bovine babesiosis in France were collected from two sources: a questionnaire sent to large animal veterinary surgeons and blood samples collected from cattle treated for clinical babesiosis. Babesia divergens was common and widespread. B major was found in only one sample. The disease was particularly widespread in north west, south west and central France. The mean clinical incidence was 0.4 per cent. The bimodal seasonality of the clinical cases was correlated with that of the tick vector (Ixodes ricinus). Of the affected animals 72.6 per cent were more than three years old.

Age Distribution↗
PubMed1995

Involvement of Candida albicans cell wall proteins in the adherence of blastospores to human buccal epithelial cells.

The adherence of Candida albicans to epithelial cells is one of the first steps in the development of candidiasis and therefore could constitute an interesting target for the prevention of infection. A yeast cell wall extract was prepared by using a C. albicans isolate (IVP 1453) highly adherent to buccal epithelial cells (BECs). This cell wall extract was separated by concanavalin A-affinity chromatography into two fractions referred to as Fr1 (proteic fraction) and Fr2 (mannoproteic fraction). The adhesion activity was mostly associated with the proteic fraction. This fraction was therefore retained and further fractionated by ion-exchange chromatography into two other fractions, referred to as Fr1a and Fr1b. The adhesion activity was mostly associated with the Fr1b fraction (56.4% adherence inhibition); it was not specific to the C. albicans isolate used during the cell wall extract preparation. The Fr1b fraction contained four major proteins with molecular masses of 30, 38, 47, and 54 kDa. Among these four proteins, those with molecular masses of 38 and 54 kDa could be involved in adherence mechanisms of C. albicans to human BECs.

Candida albicans↗
PubMed1995

Composition and antimalarial activity in vitro of volatile components of Lippia multiflora.

The essential oil of Lippia multiflora was prepared by hydrodistillation of leaves and stalks and characterized by GC and mass spectroscopy. The oil was tested for antimalarial activity on in vitro cultures of Plasmodium falciparum (FcB1-Columbia chloroquine-resistant strain and F32-Tanzania chloroquine-sensitive strain). The dilutions inhibiting the in vitro growth of the parasite by 50% 24 and 72 hr after administration of the essential oil to the parasite culture were 1/12,000 and 1/21,000, respectively. When tested on a highly synchronized culture, the essential oil inhibited growth mostly at the trophozoite-schizont step, indicating a potential effect on the first nuclear division of the parasite.

Animals↗