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Biomedical subjects

G Nosal

Publications and source records attributed to G Nosal.

18 recordsLinked to original sources
PubMed1991

The penetration of lavage solution into the periodontal pocket during ultrasonic instrumentation.

The purpose of this study was to evaluate the penetration depth of the water coolant for medicament lavage of an ultrasonic device into the periodontal pocket. Patients having teeth previously planned for extraction, and exhibiting probing depths 3 mm or greater were used in this study. A reference notch was placed on the tooth at the level of the gingival margin and the probing attachment level (PAL) was measured from the base of the notch to the base of the pocket. The ultrasonic device, with an EWPP tip and equipped with a reservoir of erythrocin dye colored coolant, was activated and moved in a vertical direction from the gingival margin to the apical extent of the pocket. The tooth was extracted and the penetration depth (PD) of the dye-colored water spray was measured from the reference notch to the apical limit of the stained subgingival plaque. The tooth was counter stained with methylene blue to determine the coronal extent of the connective tissue attachment. Pearsons' Product Moment Correlation Coefficient for the PAL and PD was calculated. Dye-stained root surface was observed along the full extent of the probe tip's penetration path. The dispersion of the dye-colored stain was localized to the area of the ultrasonic probe with very little lateral dispersion. The ultrasonic instrument may be an effective system to mechanically remove plaque and calculus at the same time as delivering a chemotherapeutic agent. The limited dispersion of the liquid dye would indicate that chemical plaque control with this delivery system is dependent upon thorough debridement with the instrument such that all affected surfaces are instrumented.

Connective Tissue↗
PubMed1982

Morphine treatment during rat pregnancy: neonatal and preweaning consequences.

Morphine treatment during pregnancy was scheduled with the view to reproduce physical dependence in female rats and to investigate the occurrence of a neonatal withdrawal syndrome (NWS) as well as more prolonged effects of the narcotic in the preweaned pups. Administration started 5 days prior to mating with the daily dose of 20 mg/kg i.p. injections. All along gestation, the dosage was gradually increased up to the final dose of 56 mg/kg/day on the 16th day when the treatment was interrupted. Pregnant dams showed behavioral manifestations of narcotic dependence and drug abstinence. At birth, morphine-exposed neonates exhibited (1) an approximate 28% decrease in respiratory rates (p less than 0.001) during the first day of life and (2) excessive crying (p less than 0.001) accompanied by restlessness. These two last features are related to clinical signs of the NWS identified in babies born to narcotic-addicted women. A significant delay in the time of eye-opening and an earlier sexual maturation in females only were also found in the postnatally developing morphine offsprings. The NWS and some other developmental changes were considered in relation to the used animal model and to possible processes involved in narcotic interferences with postnatal physical growth and neurobehavioral maturation.

Animals↗
PubMed1979

A rat model of neurobehavioral development.

The neurobehavioral evolution of the normally growing rat has been investigated by means of a series of reflex, motor and sensory tests from birth up to weaning. A sequential development of behavioral responses has been assessed over this 21-days period, and 2nd week following birth representing an important step in the neurobehavioral maturation of the rat. This rat model may be considered as an useful reference to evaluate changes that may be induced by pharmacological and toxicological agents in the developing exposed rat.

Animals↗
PubMed1979

Neuronal involution during ageing. Ultrastructural study in the rat cerebellum.

Involutive phenomena have been investigated by electron microscopy in the Purkinje Pk neuron of the cerebellar cortex of the aging rat. The still limited number of specimens available to date, however, suggest an age-related progression of morphological and functional deteriorations involving particularly the intraneuronal "nucleus-ribosome system" (NRS). The impairments are characterized by changes in the nucleolar texture. These alterations are accompanied by modifications in the repartition and relative proportion of RNP components of the nucleolus. In addition, other nuclear elements such as interchromatin and perichromatin granules may vary in importance with age. Recognizable changes in the ribosomal constituents of the NRS are evidenced by modifications in the density and distribution of free ribosomes. An altered structure and organization of GER cisternae are also evident. Furthermore, "light" cytoplasmic areas, an increased evidence of neurotubules and the gradual congestion of the pericaryon by age pigments are other valuable ultrastructural features that may be regarded as part of the sequence of morphologic events occurring during neuonal ageing. The above ultrastructural data will subsequently form the basis of a model of ageing in the nerve cell, which will complete the previously proposed model of neuronal maturation. Therefore, this long-term study essentially purports the investigation of subcellular events taking place in the Pk neuron all along the normal life span in rats. This model will also be used to evaluate the changes in the sequence and the reinforcement of the processes of evolution versus involution as affected by certain xenobiotics, such as abused drugs(alcohol and narcotics). The intraneuronal modifications found in the nuclear and cytoplasmic structures of the NRS could possibly reflect the molecular dysfunction related to the production of various types of RNA and neuronal proteins. This hypothesis is supported by biochemical data obtained from analysis of the brain of aged animals. Ultrastructural and biochemical data appear to be in good agreement with the neurophysiologic interpretation of a slow-down and reduced efficiency of the CNS during the progressive development of senescence in human and animal subjects.

Age Factors↗
PubMed1979

Saccharin- or quinine-induced changes in the rat pups following prolonged ingestion by the dam.

Effects presumably induced by a chronic free ingestion of saccharin (0.40 mg/ml) or of quinine (0.25 mg/ml) by female rats during the pregestative, gestative and lactating periods were investigated in the ensuing progeny. Preweaned pups were studied from birth up to weaning (21 days of age) by means of selected gross behavioral tests. The saccharin litters were mainly characterized by a slowering in the body growth evolution. The quinine pups demonstrate several physical anomalies: (1) congenital malformations in 5% of the animals; (2) a significantly reduced birth weight followed by a persistent growth retardation, and (3) a significant delay in the teeth eruption (1.6 and 2.6 days) and in the eye openings (1.6 days). In comparison to the untreated offspring, the saccharin pups showed minor effects whereas quinine-exposed rats were clearly impaired in several features of the postnatal physical development. Therefore, the addition of the sweetener to morphine solution may be convenient for the voluntary oral consumption of the narcotic. Conversely, quinine, used to habituate animals to drinking bitter solutions, has to be rejected in this narcotization procedure as being a harmful agent to the growing rat.

Abnormalities, Drug-Induced↗
PubMed1977

Graphological signs for extraversion.

Graphological signs of extraversion were rated from handwriting samples of undergraduates (ns = 35 males, 31 females; 23 males, 20 females) and correlated with extraversion scores from an objective psychological test. No evidence was found for the validity of the graphological signs.

Adolescent↗
PubMed1975

[Neo and postnatal development of the cerebral cortex in mice. Ultrastructural study].

Maturation in the Purkinje cell (Pk) of the cerebellar cortex of developing mice (from birth up to weaning) was investigated by structural and especially ultrastructural studies. In comparison to the adult neuron, four developmental stages were identified by studying selective morphological features (shape and size of the Pk, neuronal environment) as well as specific characteristics of neuronal constituants, particularly the "nucleus-ribosome system". The stages are: early, intermediate and late neuroblasts and young neuron. The neuronogenesis of the Purkinje cell can be summarized as follows: (a) the nuclear maturation occurs early in the development and markedly preceeds that of several organelles in the perikaryon; (b) the cytoplasmic maturation extends gradually until the young neuron state was reached. Some structures such as the granular mass and the "spotted body" in the nucleus, the nuclear envelop including its two membranes, and the ribosomal components either free or attached to the Endoplasmic Reticulum seem to exert an important role during neuronal development. Maturation processes in the Purkinje cell are generally similar in both mouse and rat and, except for some morphological and/or chronological variables, comparable in others developing nerve cells. This model of neuronal maturation is used alone or in comparison to another model of neuro-behavioral evolution which was established concommitantly. Both of these models reveal to be very useful for the evaluation of the effects induced in the developing animal following the administration of neuropsychotropic drugs such as Hallucinogens and Narcotics.

Animals↗