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Biomedical subjects

M Goffart

Publications and source records attributed to M Goffart.

At least 19 recordsLinked to original sources
PubMed1995

Bactericidal effect of beta-lactams and amikacin alone or in association against Klebsiella pneumoniae producing extended spectrum beta-lactamase.

Ten extended spectrum beta-lactamases producing strains of Klebsiella pneumoniae characterized by analytical isoelectric focusing and studied for their susceptibility to beta-lactam antibiotics, either alone or in combination with a beta-lactamase inhibitor (clavulanic acid and sulbactam) and in association with amikacin. The extended spectrum beta-lactamases were derived from either TEM (CTX-1 = TEM-3) or SHV (CAZ-4 = SHV-5). Killing curves were studied with antibiotics at clinical by achievable concentrations, at MIC and MIC x 4. At MIC, cefotetan, cefotaxime and ceftazidime lacked bactericidal activity. Imipenem was more rapidly bactericidal than meropenem or co-amoxiclav. At MIC x 4, cefotetan and cefotaxime exhibited bactericidal effect but this was less than for imipenem which gave a reduction of 4 log10 of the inoculum. Cefotaxime plus sulbactam gave no bactericidal effect compared with cefotaxime plus co-amoxiclav. A bactericidal effect with cefotaxime plus sulbactam was seen with the addition of amikacin. At clinical concentrations cefotaxime plus co-amoxiclav +/- amikacin was as efficient as imipenem +/- amikacin with a rapid bactericidal effect (5-6 log10 in 30-60 min). We proposed that cefotaxime+co-amoxiclav might be considered as an alternative to imipenem for the treatment of extended spectrum beta-lactamase associated K. pneumoniae injections.

Amikacin↗
PubMed1981

Thermoregulation in the only nocturnal simian: the night monkey Aotus trivirgatus.

The night monkey, a tropical monkey, is the only nocturnal simian; its thermoregulation was studied for comparison with other nocturnal or diurnal primates and other tropical mammals. Resting metabolic rate was 2.6 W (closed-circuit method) and 2.8 W (open-circuit method), 24 and 18% below the value predicted from body mass. The thermoneutral zone was very narrow; the lower critical temperature (LCT) was 28 degrees C and the upper critical temperature (UCT) was 30 degrees C. The body temperature (Tb) was at its minimum (38 degrees C) at an ambient temperature (Ta) of 25 degrees C, thus below the LCT. At low Ta, the increase in metabolic rate (MR) was smaller than predicted by the Scholander model, since MR intersected to a Ta 13 degrees C above Tb when extrapolated to MR = 0; this was attributed to a decrease of body surface area by behavior. The thermal conductance at the LCT was low: 2.3 W . m-2 . degrees C-1. Above the UCT, panting was the major avenue of heat loss. The response pattern of nocturnal habits, low resting metabolic rate, low thermal conductance, and panting in the night monkey, unique among simians, is found in many other mammals of tropical and hot desert habitats; it may be considered as an alternative adaptation to the thermal environment.

Animals↗
PubMed1981

Urinary excretion of catecholamines in the night monkey (Aotus trivirgatus) (Primates, Cebidae).

A seasonal variation in the urinary catecholamines output has been demonstrated in two simians kept under constant ambient conditions : the nocturnal Aotus and the diurnal Saïmiri sciureus. In Aotus, catecholamines output (NA + A), in spring, is higher than in other Primates including man and even more so in winter. Cold exposure increases the NA + A excretion in Aotus as it does in squirrel monkey and rat but the A output is particularly prominent in Saïmiri. Fasting does not alter significantly the catecholamines excretion. Associated fasting and cold exposure do not modify the adrenosympathetic response observed in Aotus in cold conditions alone, but depresses the sympathetic activity and greatly enhance the adrenomedullary excretion in squirrel monkey, as it is the case in rat. Associated fasting and cold represents a highly stressful situation for squirrel monkey but not for night monkey. Catecholamines metabolites (MN, NMN, DOPAC, HVA, VMA and MHPG) are found in urine of both species, DOPAC and VMA being predominant in Aotus but DOPAC and MHPG in Saïmiri. The proportions of conjugated forms vary according to the metabolite : DOPAC and VMA are mainly under free form but NMN, MN and MHPG are mostly conjugated in both species. The daily output of pooled adrenergic metabolites (expressed as ng/mg creatinine) is higher in Aotus than in Saïmiri and man. Both monkey species display a high adrenosympathetic activity which does not correlate with their resting metabolic rate.

Animals↗
PubMed1979

Concentrating capacity of the kidney and nitrogen partition in the urine in Perodicticus potto (Prosimii, Lorisidae, Lorisinae).

The concentrating ability of the kidney in Perodicticus potto was investigated. As the relation between this capacity and the thickness of the medulla has been stressed by Schmidt-Nielsen & O'Dell, the size of the various layers in the kidney was measured. Based on our observation that the potto may excrete uric acid in fairly high concentrations, the partition of nitrogen in the urine was also explored.

Animals↗
PubMed1977

[Hypometabolism in Aotus trivirgatus (Primates, Plathyrhini, Cebidae)].

The standard metabolism of Aotus trivirgatus (Night monkey, Owl monkey) is 22.5 to 46.2 per cent below Kleiber's prevision curve for mammals, which applies to other cebid monkeys like Saimiri sciureus and Alouatta. However the metabolic rate of Aotus is not reduced to the extent found in two hypometabolic prosimians Perodicticus potto and Nycticebus coucang. The low metabolism in Aotus is associated with a normal body temperature and a thick fur of high insulating power. These results are discussed.

Animals↗
PubMed1976

A duplex retina and the electroretinogram in the nocturnal Perodicticus potto.

The presence of cones in potto's retina has been proved beyond doubt although they are very restricted in number (1 cone for 300 rods). Morphologically, speaking there is no point in calling these cones "rudimentary" except for their slender outer segment. There are red sensitive elements in that retina at wavelengths beyond the spectral sensitivity of visual purple and it is tempting to assume that these elements are cones. The ERG evoked from these elements by red light differs from that in response to white and blue light. They dark-adapt faster than the receptors sensitive to blue and white flashes. However in some of their properties, for example fusion frequency, these cones behave like rods in other species. As these few cones seem to activate the bipolar cells nearly as effectively as the numerous rods, it is suggested that these cones may be responsible for day vision in the potto.

Animals↗
PubMed1975

[Adrenosympathetic system and thermoregulation in a prosimian Perodicticus potto].

The urinary excretion of catecholamines in Perodicticus potto (1.76-2.94 mug/kg 24 h) is in the same range as in other mammals and the activity of the adrenosympathetic system does not account for the low metabolic rate in this species. The adrenals contain 1.140 +/- 0.14 mug A + NA/mg fresh tissue, of which adrenaline constitutes 94.5 per cent and are thus practically identical to those in Macaca irus. In a cold environment the daily urinary excretion of catecholamines of the tropical but cold hardy potto is only moderately increased.

Adrenal Medulla↗
PubMed1975

[Electroretinogram in the nocturnal Prosimian Perodicticus potto].

There is histological evidence for the presence of cones in potto's retina: about 1 cone for 300 rods. The ERG of the dark adapted animal resembles that of the night monkey. In the potto's retina some red sensitive elements respond to wavelenghts beyond those which affect visual purple. The ERG evoked by these long wavelenghts differs from that produced by white light, suggesting a duplex character of the retina. These red sensitive receptors dark adapt faster than the others. However their fusion frequency is low, if compared with that in other species with a duplex retina. Nevertheless in potto the critical fusion frequency is higher for red light than for blue light.

Animals↗
PubMed1975

[Dopamine of the caudate nucleus in Perodictious potto, Macaca mulatta and Macaca fascicularis].

The dopamine, dopac and tyrosinehydroxylase contents of the caudate nucleus in the prosimian Perodicticus potto and in the simii Macaca mulatta and M. fascicularis have been estimated. The results do not support the hypothesis according to which the sluggishness of the potto is somehow related to a low dopamine content of part of the extrapyramidal system as found in the Parkinson-syndrome.

Animals↗