Biochemical investigation of atractylis gummifera L. hepatotoxicyty in the rat.
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Animals↗
Biomedical subjects
C Martin
Publications and source records attributed to C Martin.
Flavonoid synthesis in Petunia hybrida: partial characterization of dihydroflavonol-4-reductase genes.
In this paper we describe the organization and expression of the genes encoding the flavonoid-biosynthetic enzyme dihydroflavonol-4-reductase (DFR) in Petunia hybrida. A nearly full-size DFR cDNA clone (1.5 kb), isolated from a corolla-specific cDNA library was compared at the nucleotide level with the pallida gene from Antirrhinum majus and at the amino acid level with enzymes encoded by the pallida gene and the A1 gene from Zea mays. The P. hybrida and A. majus DFR genes transcribed in flowers contain 5 introns, at identical positions; the three introns of the A1 gene from Z. mays coincide with the first three introns of the other two species. P. hybrida line V30 harbours three DFR genes (A, B, C) which were mapped by RFLP analysis on three different chromosomes (IV, II and VI respectively). Steady-state levels of DFR mRNA in the line V30 follow the same pattern during development as chalcone synthase (CHS) and chalcone flavanone isomerase (CHI) mRNA. Six mutants that accumulate dihydroflavonols in mature flowers were subjected to Northern blot analysis for the presence of DFR mRNA. Five of these mutants lack detectable levels of DFR mRNA. Four of these five also show drastically reduced levels of activity for the enzyme UDPG: flavonoid-3-O-glucosyltransferase (UFGT), which carries out the next step in flavonoid biosynthesis; these mutants might be considered as containing lesions in regulatory genes, controlling the expression of the structural genes in this part of the flavonoid biosynthetic pathway. Only the an6 mutant shows no detectable DFR mRNA but a wild-type level for UFGT activity. Since both an6 and DFR-A are located on chromosome IV and DFR-A is transcribed in floral tissues, it is postulated that the An6 locus contains the DFR structural gene. The an9 mutant shows a wild-type level of DFR mRNA and a wild-type UFGT activity.
Alcohol Oxidoreductases↗
Quantal stores of excitatory transmitter in nerve-muscle synapses of crayfish evaluated from high-frequency asynchronous quantal release induced by veratridine or high concentrations of potassium.
At single voltage-clamped opener muscle fibres of crayfish claw, 10-100 mumol/l veratridine increased within a few seconds the rate of asynchronous quantal release, ñ, of excitatory transmitter from ñ less than 1 quantum/s to ñ congruent to 10,000 quanta/s. Thereafter ñ declined exponentially either with a single, tau(2) congruent to 50 s, or with two time constants tau(1) congruent to 19 s, tau(2) congruent to 50 s. In total (t----infinity), about 0.3 million quanta were released by veratridine in a single short fibre of about 1 mm length. These values were estimated by means of the noise analysis technique and they agreed with equivalent parameters of release when 100 mmol/l K+ were used as release stimulus. Strong quantal release could be elicited only once in a single muscle by veratridine. Furthermore, the effect of veratridine on quantal release could be completely prevented by pretreatment with tetrodotoxin. In another nerve-muscle preparation of crayfish, the abdominal superficial extensor muscle, up to 3 million excitatory quanta could be released by veratridine in a single fibre. In the latter muscle veratridine-induced asynchronous quantal release was strongly dependent on the extracellular concentration of Ca2+ whereas in the claw opener dependence of quantal release on extracellular Ca2+ was negligible.
Animals↗
Calcium channel current and its sensitivity to (+) isradipine in cultured pregnant rat myometrial cells. An electrophysiological and a binding study.
Action of (+) isradipine (PN 200-110), a dihydropyridine derivative, was investigated on the Ca channel current in cultured cells obtained from the longitudinal layer of the pregnant rat myometrium (18-19 days of gestation). Under our experimental conditions, the inward current was attributed to L-type inward current since: (i) equimolar replacement of Ba for Ca induced an increase in the peak current and a decrease in inactivation rate; (ii) residual inward currents were recorded at the end of the pulse; (iii) membrane potential for mid inactivation was about -40 mV; (iv) the voltage dependencies of the peak current elicited from holding potentials of -40 mV and -80 mV were similar. The inward current could be reduced with nanomolar concentrations of (+) isradipine when cells were depolarized by pulses to positive potentials. This was characterized by a pronounced initial blockade, but by no increased in blockade when pulses were repeatedly applied at a frequency of 0.05 Hz. Using the double pulse procedure we confirmed that (+) isradipine did not bind to the open-state of the Ca channels. Voltage-dependence of (+) isradipine blockade was assessed by determining the steady-state availability of the Ca channels. From the shift of the inactivation curve in the presence of (+) isradipine we calculated a (K)I value of 130 pM. Scatchard analysis of the specific binding of (+)[3H] isradipine resulted in a linear plot, thereby indicating specific binding to a single class of sites with a dissociation constant Kd of about 100 pM.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Rapid effectiveness of prednisone and thionamides combined therapy in severe amiodarone iodine-induced thyrotoxicosis. Comparison of two groups of patients with apparently normal thyroid glands.
Treatment of amiodarone iodine-induced thyrotoxicosis is often unsuccessful. Nevertheless, severe forms require a rapidly efficient therapy. Twelve patients with severe amiodarone iodine-induced thyrotoxicosis, as demonstrated on clinical and biological findings, were studied. After amiodarone withdrawal, 6 patients (group A) were treated with thionamides alone (carbimazole 60 mg daily and benzylthiouracile 1.5 g daily), and 6 patients (group B) received in addition to the same antithyroid drugs prednisone, 0.50 to 1.25 mg/kg/day for 40 days; in group A, T4 levels did not change over the study period of 40 days; T3 levels decreased only after 30 days; clinical status did not improve. In group B: T3 and T4 levels decreased dramatically at 10 days of treatment, to values significantly lower than in group A; clinical improvement occurred mainly in patients treated with high doses of prednisone; elevated thyroglobulin levels diminished rapidly. Improvement was maintained after cessation of prednisone. The rapid effect of prednisone suggests an impairement of proteolysis of thyroglobulin possibly due to a lysosomal action.
Adult↗
A preliminary comparison of flat affect schizophrenics and brain-damaged patients on measures of affective processing.
Flat affect is a major component of schizophrenia and is often also seen in neurological disorders. A preliminary set of comparisons were conducted to delineate neuropsychological mechanisms underlying flat affect in schizophrenia, and new measures are described for the assessment of affective deficits in clinical populations. Subjects were schizophrenic with flat affect (SZs), right brain-damaged (RBD), Parkinson's Disease (PDs), and normal control (NC) right-handed adults. Subjects were administered affective measures of expression and perception in both facial and vocal channels. For both perceptual and expressive tasks the SZs performed significantly less accurately than the NCs and the PDs but did not differ from the RBDs. This was the case for both face and voice. This finding lends support to the speculation that right hemisphere mechanisms, especially cortical ones, may be compromised among schizophrenics with flat affect.
Adult↗
Failure of behavioral dependence induction and oral nicotine bioavailability in rats.
As failure to induce behavioral dependence to oral nicotine (0.31 mM) might be caused by taste aversion. Sixteen rats were presented nicotine around the taste aversion threshold (0.025 mM then 0.05 mM) as only source of fluid for 10 weeks. Eight of them had undergone portacaval anastomosis (PCA) to increase bioavailability of nicotine by preventing liver first-pass. Weekly choice sessions between nicotine and water demonstrated neither aversion nor preference for nicotine. In 10 control and 11 PCA rats accustomed to drink 0.31 mM nicotine, plasma nicotine was determined after 3 ml/kg intragastric nicotine-solution. In both groups, 0.05 mM nicotine did not lead to detectable levels but 0.31 mM nicotine led to peak levels higher than seen in man after smoking. Similar levels were recorded after spontaneous nicotine drinking in 8 isolated and 18 grouped normal rats accustomed to 0.31 mM nicotine. Drinking nicotine for at least 10 weeks did not induce behavioral dependence in these rats. This cannot be explained by poor nicotine bioavailability by oral route.
Administration, Oral↗
Eating attitudes and taste responses in young ballerinas.
The Eating Attitude Test 40 (EAT 40) was administered to 23 ballerinas (mean age 18.3 +/- 0.9 years). The scores were high, as they are in anorexic patients. The EAT 40 revealed anorexic-like attitudes in dancers: selective food restrictions, severe dieting, constant preoccupations with food. However, dancers scored low at items screening bulimia, vomiting or laxative abuse. The dancers' perceptions and preferences for sweetness and fat food content were examined and compared to those of 14 sedentary controls. Taste stimuli were 20 semiliquid mixtures of soft-white cheese (0, 3 or 7 grams of fat per 100 grams) or heavy cream (30% fat), and sweetened with 1, 5, 10, 20 or 40% sucrose. The subjects used a 9-point category scale to rate the perceived sweetness, fat content, and hedonic value of the stimuli. There were no significant differences in the perceived sweetness intensity between groups, but the perception of fat appeared to be better in dancers, in particular in very sweet stimuli. Dancers showed a clear aversion for the fattest stimuli. In young female dancers, enhanced sensitivity for alimentary fats is associated with decreased preferred levels.
Adolescent↗
Phage typing of Listeria monocytogenes.
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Animals↗
Radiographic definition of the dorsal and palmar edges of the distal radius.
The dorsal and palmar edges of the distal radius, as well as the concavity of the articular surface were labeled with wire and radiographs taken from neutral to 30 degrees of added dorsal tilt. The dorsal edge was identified as the structure that protrudes distally in neutral. The palmar edge was found to overlap with the sclerotic subchondral bone of the radius in neutral. With increasing dorsal tilt the profile of the palmar edge appeared as it protruded distal to the sclerotic subchondral line of the radius. The profile of the palmar edge could be distinguished from that of the dorsal edge on the anteroposterior view. The wire, which was placed midway between the dorsal and palmar edges and the concavity of the articular surface corresponded to the prominent sclerotic subchondral bone line of the distal radius. This did not change in position with increasing dorsal tilt. This clarification of the radiologic anatomy is helpful in extending the use of the anteroposterior radiograph for the interpretation of fractures and malunions of the distal radius.
Humans↗
Cell wall constituents of Microcystis sp. PCC 7806.
Cell walls of Microcystis sp. PCC 7806 were purified from cell homogenates by sucrose density centrifugation and Triton X-100 extraction. The outer membrane contained carotenoids, two major peptidoglycan-associated proteins (Mr 49,000 and 52,000), and lipopolysaccharide (LPS) as indicated by the presence of 3-hydroxy fatty acids (3-OH-14:0, 3-OH-16:0, 3-OH-18:0), 4-oxo-18:0 fatty acid, and GlcN as lipid A components in addition to rare O-methyl sugars (2-O-methyl-6-deoxyhexoses I and II). The peptidoglycan (A1 gamma-type) was found to be covalently linked to a wall polysaccharide composed of GlcN, ManN, Man, Glc, and phosphate.
Carotenoids↗
[Arterial thrombosis and infection in prolonged catheterization of the dorsal artery of the foot].
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Arteries↗
[Use of norepinephrine in the treatment of septic shock].
The effects of noradrenaline were studied in 16 patients, with either a hyperkinetic septic shock syndrome or a septic shock resistant to dobutamine treatment. The study aimed to restore normal tissue perfusion pressure, assessed by a return to normal of urine output or blood pressure. An optimal left ventricular filling pressure, estimated by the pulmonary capillary wedge pressure, was obtained for each patient using a Swan-Ganz catheter. The administration of 10.6 +/- 0.5 micrograms.kg-1.min-1 dobutamine (starting dose: 6 micrograms.kg-1.min-1) was started when the cardiac index (CI) was less than 3.3 l.min-1.m-2 after vascular filling with plasma expanders. Patients became eligible for noradrenaline treatment when they fulfilled the following conditions: arterial systolic pressure (Pasys) less than or equal to 90 mmHg; systemic vascular resistances less than or equal to 600 dyn.s.cm-5; CI greater than 3.5 l.min-1.m-2; persistent oliguria (less than 30 ml.h-1). This drug was given at a constant rate with a starting dose of 0.5 micrograms.kg-1.min-1, increased every 10 min by 0.3 to 0.6 micrograms.kg-1.min-1 according to the effects on Pasys and hourly urine output. Eight patients received noradrenaline alone; the efficient dose was 0.9 +/- 0.2 micrograms.kg-1.min-1, and it was used for a mean 5.1 +/- 1 days. CI increased in those patients who were given both noradrenaline and dobutamine. Thirteen out of the 16 patients had a dramatic increase in urine output; only three patients remained oliguric. There were no effects on serum creatinine concentration, anion gap, intrapulmonary shunt and oxygen consumption.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
[Value of a cumulated prognostic index in the development of severe peritonitis with adult respiratory distress syndrome].
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Humans↗
Experimental corneal studies with the excimer laser.
The excimer laser is potentially capable of achieving wide area central corneal reprofiling because of its extreme precision and limited penetration into adjacent tissues. A beam modifying system designed for this application is described. Initial clinical studies in monkeys and in ten human patients with blind eyes were performed. Long-term clinical data and interim histologic analyses are available from these studies. The results indicate that following ablation with an ultraviolet laser in both humans and primates, the ablated tissue shows a normal healing reaction resulting in a mild to moderate stromal interface haze. The effects of this healing on best corrected vision must be elucidated through additional research. Some loss of refractive effect was seen early in the healing process with apparent stabilization.
Animals↗
Cerebral laterality and depression: differences in perceptual asymmetry among diagnostic subtypes.
Examined the influence of diagnostic subtype of depression on perceptual asymmetry for dichotic listening and visual tachistoscopic tasks. A total of 65 unmedicated patients with major depressive disorders and 30 normal controls were tested on a verbal and nonverbal task in each modality. Patients diagnosed according to the DSM-III with melancholia had abnormal perceptual asymmetry for dichotic nonsense syllable and complex tone tasks. In contrast, patients having a nonmelancholic "atypical depression" (reactivity of mood with preserved pleasure capacity and associated features) did not differ from normal controls on these tasks, but had an increased incidence of left handedness. Bipolar depression (history of hypomania) differed from unipolar depression in showing abnormal perceptual asymmetry for a tachistoscopic dot enumeration task. Alterations of perceptual asymmetry in melancholia and bipolar depression were consistent with hypothesized right hemisphere dysfunction.
Adolescent↗
Molecular analysis of a transposon-induced deletion of the nivea locus in Antirrhinum majus.
The transposable element Tam3 of Antirrhinum majus is capable of causing large-scale chromosomal restructuring. It induced a large deletion at the nivea locus, to produce the allele niv-:529. The deletion removed the entire nivea coding region while the element remains intact with the potential to induce further rearrangements. Genetic experiments showed that the endpoint of the deletion (called x) is closely linked to nivea. The DNA sequences of niv-:529, a genomic excision of Tam3 from niv-:529, and the original genomic position of x have been determined. These data suggest that the deletion could have resulted from an abortive transposition or through breakage and religation.
Alleles↗
Thymic epithelium tolerizes chickens to embryonic graft of quail bursa of Fabricius.
We demonstrated previously that isotopic and isochronic grafts of the quail bursa of Fabricius rudiment performed at 5 days of incubation (E5) into chick embryos resulted in the development of a chimeric bursa whose chick host B lymphocytes and accessory cells differentiated in a foreign, quail epithelial environment. Such animals reject their grafted bursa by the age of 2-3 weeks post-hatching (1,2). Isotopic embryonic grafts of the thymus epitheliomesenchymal anlagen from the quail donor of the bursal rudiment were carried out at E4.5 (before their colonization by hemopoietic precursor cells), following partial or complete host thymectomy. The quail thymic epithelial stroma was accepted and invaded by chick hemopoietic precursor cells that further differentiated into lymphocytes and dendritic cells. Tolerance of the foreign bursa was induced in such thymobursal chimeras. This demonstrates that the thymic epithelium has the capacity to induce tolerance of xenogeneic rudiments when both grafts are implanted at early stages of embryonic development. We also report on the production of two birds in which removal of the chick host thymus was complete thus generating chimeras in which host T and B lymphocytes differentiated in a completely xenogeneic epithelial environment.
Animals↗