Respiratory response to acute metabolic acidosis.
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Biomedical subjects
Publications and source records attributed to G van Melle.
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A study on 122 full-term newborns with cerebral distress has given the basis for a mathematical model allowing to calculate the risk of poor evolution due to neurological disorders occurring in the first week of life. For each patient a score on his neurological status is established at 3 or 7 days of age. Only four essential neurological characteristics have to be considered: primary reflexes, convulsions, apathy or swallowing disorders, respiratory disorders. All possible score combinations are listed, and each of them is associated with a risk factor (in percent) for poor evolution. A long-term prognosis can therefore be obtained by simple clinical observation, making a score and consulting the list.
A statistical technique for the estimation and differentiation of the operational kinetic parameters for influx of solutes into intestinal rings incubated in vitro is presented. Influx data were fitted to an equation comprising the sum of saturable and diffusional components; the latter is assumed to include entry into the extracellular space, thus avoiding the necessity of indirect assessment with space markers. The estimations are made by non-linear regression analysis on a logarithmic scale. Comparison between data sets is carried out by performing a joint fit under the restriction of parameters common to the two sets. If an F-test reveals no significant loss of information, then the parameter(s) in question do not differ from one set to another. The method is illustrated by an experiment to determine which kinetic parameters for influx of beta-methyl-D-glucoside are altered when sodium is removed from the incubation medium. The results show that the Km is principally affected by this manoeuvre.
Marked atrophy of the mucosa develops in self-emptying blind loops of rat jejunum. The application of microdissection techniques revealed a 74% reduction in the mucosal surface area of the blind loops, 3 weeks after their creation. Kinetic studies of the influx of L-phenylalanine and beta-methyl-D-glucoside into rings of blind loops showed that the Km for both mechanisms was unchanged, but that there was a small reduction in the Vmax for both substrates, when expressed in terms of unit weight of incubated tissue; this attained 31% for phenylalanine and 12% for beta-methyl-glucoside. When the kinetic data were combined with the morphometric results, it could be shown that the Vmax for both substrates, when expressed per unit area of mucosal surface, was more than twice as large in the blind loop epithelium as in normal tissue. Such findings indicate either that the individual cells of the blind loop epithelium possess more transport sites than normal, or that there is a greater proportion of absorptive cells within the blind loop mucosa.
40 leg ulcers were treated for 6 weeks by application twice a day of a 20% benzoyl peroxide lotion. Each ulcer was regularly measured and its bacterial flora was determined. Therapeutic results were very satisfactory: the average healing rate of the ulcers was 62.8% of the initial wound area after 4 weeks of treatment and 76.5% after 6 weeks of treatment. The bacterial flora of the ulcers changed during treatments, streptococci and staphylococci disappeared. Pseudomonas aeruginosa became abundant.
The level of cerebrospinal fluid (CSF) glucose may be lowered after subarachnoid hemorrhage. This was observed in each of 18 cases of proven posthemorrhagic hydrocephalus in infants (study group). In one of these children with a hemorrhagic spinal fluid and hypoglycorrhachia unaccompanied by clinical signs of intracranial hemorrhage or hydrocephalus, the axial tomography showed a significant although asymptomatic hydrocephalus. To further evaluate the significance of this finding (hypoglycorrhachia), we compared the incidence of hypoglycorrhachia (CSF glucose less than 40 mg) and lowered CSF glucose/blood glucose ratio (ratio less than 0.4) at three similar time intervals from the presumed time of the intracranial hemorrhage in the study group with that of a control group of 40 neonates with similar neonatal associated pathology (mainly premature infants with hyaline membrane disease) but who did not later develop posthemorrhagic hydrocephalus or cerebral palsy. There was a statistically greater frequency of these anomalies in the hydrocephalic group. Only 3 of the 40 control patients had hypoglycorrhachia and low ratio. Hypoglycorrhachia in the absence of other known causes for decreased CSF glucose is a good index of a probably significant meningeal hemorrhage with a high risk of secondary hydrocephalus which may or may not be symptomatic. Hypoglycorrhachia may be used as an indication of the frequency of clinically inapparent subarachnoid hemorrhage in these high risk newborns.
A clinical and electroencephalographic study of 107 neurologically normal children with partial seizures was undertaken to verify the existence and determine the frequency of epileptic syndromes reported in selected populations. Sixty-three children had simple partial seizures, 39 had complex partial seizures, and 5 children were unclassifiable. The syndrome of benign partial epilepsy of children with rolandic spikes (BPEC, 38 cases) was clearly identified and its uniformly benign final prognosis was confirmed even if some of these children had at times severe or poorly controlled seizures. Among the children with simple partial seizures outside the BPEC (25 cases) and complex partial seizures (39 cases), no homogeneous clinical or electroclinical subgroup could be found. Two children with benign partial epilepsy and myoclonic-astatic seizures ("atypical benign partial epilepsy of childhood") and one child with "benign epilepsy with occipital spike-waves" were identified. 74% of children with epilepsy with complex partial seizures (ECP) had a 1-year seizure-free interval, and many children with epilepsy with simple partial seizures outside the BPEC group (ESP) had no more than two seizures. A benign course is thus not limited to the BPEC but is difficult to predict. Prospective studies are necessary to confirm the existence of well-defined benign syndromes among the idiopathic partial epilepsies of childhood, which appear quite rare outside the BPEC.
Retinoblastoma is a malignancy of the human developing retina. In situ as well as in vitro studies have attributed tumoral histogenesis either to a primitive retinoblast with neuronal and glial differentiation potentials, or to a photosensory progenitor cell. Here it is shown in vivo that the retinal topography of 457 retinoblastoma and retinoma foci is radially asymmetrical. Tumor density appears to mimic the horizontal visual streak characteristic of red/green cone cell distribution. Such a non-random distribution seems to invalidate the hypothesis of a primitive multipotential neuroblast as the unique source of retinoblastoma and may support the view that retinoblastoma evolves along the cone cell lineage.
Physiological finger tremor was assessed by two-dimensional solid accelerometry in 40 healthy normal subjects at rest (R) with the hand hanging over the armrest of a chair, in posture (P) with the arm rested on the armrest but the hand extended from the wrist, and finally adding proximal muscles contraction in extension (E) with the arm extended in front of the patient, each time with and without mental stress. The mean amplitude for physiological tremor, about 30 microns, was almost doubled by hand extension and increased by 4 to 5-fold by arm extension with further increase by mental stress in each position, which gives a good estimation of the contribution of proximal and distal muscles into the amplitude of physiological tremor. There was no significant effect of age between 20 and 60 years on tremor amplitude, but mean tremor frequency decreased significantly between 40 to 60 years. Mental stress increased amplitude but decreased tremor frequency of both across all position, possibly by increasing the synchronization of motor unit firing and by modifying the gain of the motoneurones and the stretch reflex as shown by electrophysiological studies.
OBJECTIVE: The objective of this study was to analyse the long-term mortality and morbidity of a group of patients undergoing thrombolysis during the acute phase of myocardial infarction and to determine the factors influencing the prognosis. One hundred and seventy five patients (149 mean and 26 women, mean age: 54 years) were included in a randomized study, comparing the efficacy of 2 thrombolytic substances administered during the acute phase of myocardial infarction. A standard questionnaire was sent to the various attending physicians to follow-up of these 175 patients. RESULTS: The hospital mortality was 5% (9 patients) and 14 patients (9%) died after a mean follow-up of 4.3 +/- 2.1 years. The 5-year actuarial survival was 81%. Fourteen patients (8%) were lost to follow-up and 49 patients (32%) underwent surgical or percutaneous revascularization during follow-up. Revascularized patients had a significantly better survival than non-revascularized patients. The mean left ventricular ejection fraction of patients who died was lower (48% versus 71%) than that of survivors. Patients with an ejection fraction < 40% also had a significantly lower survival (p = 0.01). Patency of the vessel after thrombolysis was associated with a slightly better survival; this difference was not significant. The ejection fraction at 6 month was also significantly higher (60 +/- 10% versus 49 +/- 11%) for patients with a patent artery. Three risk factors for death or reinfarction were identified: age > 65 years at the time of infarction, disease in more than one coronary vessel and absence of angina pectoris before infarction. The probability of a coronary accident varied from 2 to 88% according to the number of risk factors present. At the time of follow-up, 60% of patients presented hypercholesterolaemia versus only 7% before infarction 73% of patients received anticoagulant or antiaggregant treatment and 81% of patients were asymptomatic. CONCLUSION: The mortality and the acute and long-term morbidity of myocardial infarction remain high, as only 34% of our patients did not develop any events during follow-up, despite serious medical management and follow-up. The ejection fraction has an important prognostic value. Patient management should take the abovementioned risk factors into account.