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Biomedical subjects

C Peter

Publications and source records attributed to C Peter.

At least 19 recordsLinked to original sources
PubMed2000

The role of clinical suspicion in evaluating a new diagnostic test for active tuberculosis: results of a multicenter prospective trial.

CONTEXT: In laboratory trials, nucleic acid amplification tests for the diagnosis of tuberculosis (TB) are more accurate than acid-fast bacilli (AFB) smear microscopy and are faster than culture. The impact of these tests on clinical diagnosis is not known. OBJECTIVE: To assess the performance of a nucleic acid amplification test, the enhanced Mycobacterium tuberculosis Direct (E-MTD) test, against a uniform clinical standard stratified by level of clinical suspicion. DESIGN: Prospective multicenter trial conducted between February and December 1996, documenting the clinical suspicion of TB at enrollment and using final comprehensive diagnosis as the criterion standard. SETTING: Six urban medical centers and 1 public health TB clinic. PATIENTS: A total of 338 patients with symptoms and signs consistent with active pulmonary TB and complete clinical diagnosis were stratified by the clinical investigators to be at low (< or =25%), intermediate (26%-75%), or high (>75%) relative risk of having TB. MAIN OUTCOME MEASURES: Sensitivity, specificity, and positive and negative predictive values of the E-MTD test in clinical suspicion of groups with low (n = 224); intermediate (n = 68); and high (n = 46) clinical suspicion of TB. RESULTS: Based on comprehensive clinical diagnosis, sensitivity of the E-MTD test was 83%, 75%, and 87% for low, intermediate, and high clinical suspicion of TB, respectively, and corresponding specificity was 97%, 100%, and 100% (P = .25). Positive predictive value of the E-MTD test was 59% (low), 100% (intermediate), and 100% (high) compared with 36% (low), 30% (intermediate), and 94% (high) for AFB smear. Corresponding negative predictive values were 99%, 91%, and 55% [corrected] (E-MTD test) vs 96%, 71%, and 37% (AFB smear). CONCLUSIONS: For complex diagnostic problems like TB, clinical risk assessments can provide important information regarding predictive values more likely to be experienced in clinical practice. For this series, a clinical suspicion of TB was helpful in targeting areas of the clinical spectrum in which nucleic acid amplification tests can make an important contribution.

Adult↗
PubMed1999

Tobacco BY-2 cell-free extracts induce the recovery of microtubule nucleating activity of inactivated mammalian centrosomes.

The structure and the molecular composition of the microtubule-organizing centers in acentriolar higher plant cells remain unknown. We developed an in vitro complementation assay where tobacco BY-2 extracts can restore the microtubule-nucleating activity of urea-inactivated mammalian centrosomes. Our results provide first evidence that soluble microtubule-nucleating factors are present in the plant cytosolic fraction. The implication for microtubule nucleation in higher plants is discussed.

Centrosome↗
PubMed1998

Does tacrolimus cause more severe anemia than cyclosporine A in children after renal transplantation?

Initial reports indicated the possibility of severe anemia associated with tacrolimus (TC) therapy. We investigated the degree of anemia under TC treatment in comparison to cyclosporine A (CsA) treatment in children after renal transplantation. A cross-sectional analysis of 95 children successfully transplanted for at least 3 months was performed. Eighty-five children received CsA and 10 TC. TC-treated patients were compared with CsA-treated patients who were matched according to age, gender, creatinine clearance, and time after transplantation. No patient received additional therapy with mycophenolate mofetil or azathioprine. The creatinine clearance of the whole group of transplanted children was 58 ml/min per 1.73 m2. The patients within the matched-pair analysis had a lower creatinine clearance (TC 46 and CsA 48 ml/min per 1.73 m2). The hemoglobin was 10.3 g/dl for the TC-treated children and 10.4 g/dl among the CsA-treated patients. Numerically, EPO was higher and iron lower in the TC group than in the CsA group. Among children with functioning renal grafts, a correlation exists between Hb and creatinine clearance. A significant difference in the degree of anemia between TC- and CsA-treated children could not be found.

Adolescent↗
PubMed1998

Trichothiodystrophy without associated neuroectodermal defects.

Trichothiodystrophy leading to generalized trichorrhexis nodosa-like hair changes with abnormal hair breakage is described in a 4-year-old girl. A marked deficiency of sulphur and the sulphur-containing amino acid, cystine, was detected in the biochemical analysis of the hair. Further investigation of the hair showed the morphological criteria of trichothiodystrophy. Commonly related symptoms, such as mental retardation, ichthyosis and increased sensitivity to sunlight, were not present in our patient.

Child, Preschool↗
PubMed1998

Opposing effects of glycerol on the protective function of the horny layer against irritants and on the penetration of hexyl nicotinate.

BACKGROUND: It is known that glycerol in an oil-in-water emulsion has a protective effect against irritating substances. OBJECTIVE: To answer the question: is the protection effect of glycerol based on a regenerative process? METHODS: Upon irritation by either tape stripping or acetone treatment, we applied glycerol to the skin surface under an occlusive dressing to create transepidermal water movement. As a control we used water under the occlusive dressing on the contralateral forearm. After 5 h we compared the barrier function using biological tests. RESULTS: A significant improvement of the protective barrier function was observed in the glycerol-treated areas, as shown by the alkali resistance and by the irritant effect of dimethyl sulfoxide (DMSO) as well as sodium lauryl sulfate. Surprisingly, at the same time penetration of hexyl nicotinate improved on the glycerol-treated areas. A direct physicochemical protection effect on the surface of the skin was ruled out in additional studies using NaOH and DMSO. CONCLUSIONS: Under the given conditions glycerol leads to a more rapid reconstitution of the protective skin barrier and initiates a regenerative skin protection. In contrast to that, it is acting as a penetration enhancer.

Adult↗
PubMed1994

Gas chromatographic-mass spectrometric determination of ibuprofen enantiomers in human plasma using R(-)-2,2,2-trifluoro-1-(9-anthryl)ethanol as derivatizing reagent.

A relatively rapid, inexpensive, sensitive and stereospecific gas chromatographic-mass spectrometric method was developed for the quantification of S(+) and R(-)-ibuprofen in human plasma. This method uses a commercially available internal standard and has no interference from endogenous substances nor metabolites. The method involves derivatization of ibuprofen enantiomers with optically active R(-)-2,2,2-trifluoro-1-(9-anthryl)ethanol using oxalyl chloride as the coupling reagent. The subsequently formed diastereoisomers are separated by gas chromatography and analysed by mass spectrometry using selected-ion monitoring. The assay is successfully applied to a pharmacokinetic study. The simplicity, sensitivity and precision of the method make it convenient for the quantification of ibuprofen enantiomers in biological samples.

Anthracenes↗
PubMed1994

Characterization of a 100-kDa heat-stable microtubule-associated protein from higher plants.

In higher-plant cells, the different cell-cycle-dependent microtubule arrays are involved in a wide range of activities including chromosome segregation, cell-plate formation and cellulose microfibril distribution and orientation. A wealth of data, obtained using animal cells, has indicated that the differential stability and function of microtubules during cell-cycle and/or differentiation could be primarily regulated by selective microtubule-associated proteins (MAP). Compared to animal MAP, our knowledge of plant MAP is so far very limited. In this study, we have identified a maize heat-stable protein with apparent molecular mass 100 kDa (P-100) which binds to taxol-stabilized neurotubules and copolymerizes in vitro with purified neural tubulin. Moreover, P-100 cross-reacts with affinity-purified tau antibodies like a maize 83-kDa putative MAP described previously [Vantard, M., Schellenbaum, P., Fellous, A. & Lambert, A. M. (1991) Biochemistry 30, 9334-9340]. Polyclonal antibodies directed against P-100 were obtained and indicated that this protein is found in diverse higher-plant cultured cells suggesting the ubiquitous nature of this protein. P-100 can be phosphorylated in vitro by protein kinases present in a maize cytosol extract. Together, our data suggest that P-100 could be a higher plant MAP.

Blotting, Western↗
PubMed1993

Higher plant microtubule-associated proteins: in vitro functional assays.

Microtubule-associated proteins (MAPs) can account for the assembly and stabilization of microtubules at low tubulin concentration, for their ability to interact with other microtubules and/or cytoskeletal polymers or organelles and also for regulating microtubule anchoring and bundling properties. The data concerning higher plant MAPs remain limited so far to a few examples. Motor MAPs such as dynein or kinesin remain poorly documented in plants and are not to be discussed here. In this manuscript, the attention is focused on structural MAPs which co-assemble with tubulin during microtubule assembly. Using taxol, we developed an assay where higher plant microtubules were induced to self-assemble in a cytosolic extract of maize cultured cells and could be used as a native matrix for the isolation of putative higher plant MAPs. Seven polypeptides with molecular masses ranging between 60-125 kDa were found in this MAP-enriched fraction. These putative plant MAPs were shown to co-assemble with pig brain tubulin through two cycles of temperature-dependent assembly-disassembly. They were able to initiate and promote MAP-free tubulin assembly under conditions of non-efficient self-assembly and induced bundling of both plant and neural microtubules. One of these polypeptides (83 kDa) was found to be immunologically related to neural tau, suggesting the presence of common epitopes between neural and plant MAPs. Such epitopes may be present at the microtubule-binding domains, as the higher plant MAPs co-assemble with brain tubulin. Plant microtubules exhibit an important in situ bundling activity, as in cortical or pre-prophase band arrays, or during the drastic reorganization of the cytoskeleton during mitosis induction.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

[CHILD syndrome. Case report of a rare genetic dermatosis].

We report on a 2-month-old girl who developed unilateral ichthyosiform erythrodermia on the right side of her trunk and the right leg 1 week after birth. In addition, there was hexadactyly of her right hand. Apart from that, close physical examinations did not reveal any other defects. We diagnosed this condition as CHILD syndrome (congenital hemidysplasia with ichthyosiform nevus and limb defects).

Biopsy↗
PubMed1992

Allergy to honey: relation to pollen and honey bee allergy.

To identify the allergenic components of honey we studied 22 patients with a history of systemic allergic symptoms following honey ingestion. The group of honey-allergic patients was compared with three control groups: 10 subjects sensitized to artemisia, 10 with honey bee venom allergy and 10 without a history of atopy or bee sting reactions. The allergological tests included skin tests and RAST with three different kinds of Swiss honey (dandelion, forest and rape), pollen of compositae species, celery tuber, extract of bee pharyngeal glands, honey bee venom and bee whole body extract. The results show that 3/4 of honey-allergics are sensitive to dandelion honey and 13 of 22 also to compositae pollen. Nine of the honey allergic patients were sensitized to honey bee venom, 3 also to bee pharyngeal glands and to bee whole body extract. Analysis of diagnostic tests and RAST inhibition studies suggest that besides compositae pollen other allergens, most likely of bee origin are important. In honey allergics primary sensitization may be due either to the honey itself, to airborne compositae pollen or even to cross-reacting bee venom components.

Adolescent↗
PubMed1992

[Atypical verbal behavior in a 30 year follow-up of an acquired aphasia-epilepsy syndrome].

Detailed study of the communication of one of the patients followed-up by Deonna et al. (1989) who has been suffering since age seven of an atypical acquired aphasia-epilepsia syndrome. Seizures as well as peculiar verbal productions persist at adult age. After a thirty year follow-up, only a small lexicon has been acquired, mostly made of onomatopeia and idiosyncrasies. We describe this lexicon and discuss the quality of the communication in a real-life ecological situation. We then compare it to the jargon and the aphasic productions of the standard neuropsychological examination.

Adult↗
PubMed1989

Adult follow-up of the acquired aphasia-epilepsy syndrome in childhood. Report of 7 cases.

The authors report at adult age 7 patients (6 men, one woman) with the syndrome of "acquired aphasia-epilepsy", 6 of which had been previously studied as children. The results of the language, neuropsychological and socio-educational evaluation detailed many years after the onset of the aphasia are the subject of this report. One man has recovered completely, one has a normal oral language but is severely dyslexic, one has recovered normal comprehension but has severe expressive language problems. Four have absent language comprehension and lack of expressive speech, and only one of them has learned and is using sign language with some efficiency. None has developed functional written language. Attempts to offer a substitutive language to children with prolonged inability to understand and use oral language appears important but is fraught with problems. Although there are no conclusive data about the role of the continuous paroxysmal EEG discharges and the effect of their suppression with drug treatment on the prognosis of the aphasia, the definite fluctuations of the aphasia in some cases, the isolated recent case reports of definitive improvement with drug treatment justify further trials in this potentially severe and chronic condition.

Adolescent↗
PubMed1987

Norfloxacin: review of safety studies.

The tolerability profile of norfloxacin, the first of a new generation of fluoroquinolone carboxylic acid antibacterials, has been defined in numerous laboratory animal and human trials. Whether administered for moderate or protracted periods, norfloxacin has been relatively safe in animals over a wide range of doses. There has been no evidence of a teratogenic effect in any of the animal species tested (rat, rabbit, mouse, monkey) at six to 50 times the human dose (400 mg twice daily). However, norfloxacin has been shown to produce embryonic loss in monkeys when given in doses 10 times the maximal human dose, resulting in peak plasma levels that are two to three times those obtained in humans. Although there are no adequate and well-controlled studies in pregnant women, norfloxacin is not recommended for use in this population because it, like other drugs in this class, causes arthropathy in immature animals. In animals, norfloxacin is neither mutagenic nor carcinogenic, and, in clinical trials, norfloxacin-related adverse experiences have been uncommon. Those that have occurred have been generally mild, requiring discontinuation of therapy in less than 1 percent of patients. The most frequently reported side effects have been nausea, dyspepsia, headache, and dizziness. Administration of 400 mg of norfloxacin at two or three times a day has been associated with reasonably good gastrointestinal tolerance.

Animals↗
PubMed1986

Comparative evaluation of New York City and modified Thayer-Martin media for isolation of Neisseria gonorrhoeae.

Commercially manufactured New York City (NYC) medium and modified Thayer-Martin (MTM) medium were compared for their ability to isolate Neisseria gonorrhoeae from clinical specimens. Twenty-seven public health laboratories throughout California evaluated 4,802 specimens collected from patients attending either sexually transmitted disease or family planning clinics. Total of 726 and 737 N. gonorrhoeae isolates were recovered from NYC and MTM medium, respectively. Although less contamination was noted on NYC medium, MTM medium was equivalent to commercially prepared NYC medium for the isolation of N. gonorrhoeae from clinical specimens.

Cervix Uteri↗
PubMed1984

[Arteriovenous fistulae for periodic hemodialysis: a simple procedure for correcting distal complications of venous origin].

A method is proposed for treatment of venous stasis responsible for edema and trophic disorders of the hand after side-to-side arteriovenous fistula at the wrist. A full lumen anastomosis is performed between the cephalic vein of the thumb (distal in relation to the fistula) and the superficial cubital vein, using a subcutaneous tunnel created on the dorsal surface of the wrist. Applied to 7 patients this procedure led to regression of edema, and only one case of thrombosis in the 2nd postoperative month. In the other 6 patients the newly formed anastomosis remained permeable when examined after a mean follow up of 3 years.

Edema↗