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Biomedical subjects

R Bianchi

Publications and source records attributed to R Bianchi.

At least 235 records · Page 13Linked to original sources
PubMed1987

Correlation of CA125 and CA19-9 serum levels with clinical course and second-look findings in patients with ovarian carcinoma.

CA125 and CA19-9 levels were serially evaluated in blood samples from 21 patients during and after integrated surgical and chemotherapeutic treatment for ovarian carcinoma. Serial measurement of CA125 and CA19-9 correlated with clinical course of disease in 89.7 and 72.7% of instances, respectively. The decrease of serum CA125 and/or CA19-9 in the normal range at the end of chemotherapy does not exclude the presence of residual disease, which can be accurately evaluated only by second-look laparotomy. Serum CA125 and/or CA19-9 can raise some months before clinical and ultrasonographic detection of recurrence. CA125 is the most reliable marker in ovarian carcinoma; however, the concomitant measurement of CA19-9 could offer some benefit in the monitoring of patients with this neoplasia.

Antigens, Neoplasm↗
PubMed1987

Role of serum carrier proteins in the peripheral metabolism and tissue distribution of thyroid hormones in familial dysalbuminemic hyperthyroxinemia and congenital elevation of thyroxine-binding globulin.

To investigate the role of thyroxine-binding globulin (TBG) and albumin in the availability of thyroid hormones to peripheral tissues, comprehensive kinetic studies of thyroxine (T4) and triiodothyronine (T3) were carried out in eight subjects with familial dysalbuminemic hyperthyroxinemia (FDH), in four subjects with inherited TBG excess, and in 15 normals. In high-TBG subjects, the reduction of T4 and T3 plasma clearance rates (by 51% and 54%, respectively) was associated with normal daily productions; T4 and T3 distribution volumes were significantly reduced. In FDH subjects T4 clearance was less reduced (by 31%) than in high TBG; consequently T4 production rate was significantly increased (by 42%); T4 and T3 distribution volumes and T3 clearance rate were unchanged. Increased T3 peripheral production in FDH (by 24%) indicates that T4 bound to abnormal albumin is more available to tissues than T4 carried by TBG, thus suggesting an important role of albumin in T4 availability to the periphery.

Adult↗
PubMed1987

Effect of calcium on adenylate cyclase of rat anterior pituitary gland.

The effect of free calcium (Ca2+) on adenylate cyclase (AC) activity of rat anterior pituitary gland have been investigated in order to shed some light on the interrelationships between the two second messengers (cAMP and calcium) which operate in pituitary cells. Anterior pituitary homogenates or crude membranes preparations (obtained using buffers free of divalent cation chelators) were assayed and the concentrations of Ca2+ in the assay mixture containing EGTA were calculated by a computer program for each addition of CaCl2. A wide range of Ca2+ concentrations (from 2 X 10(-9) to 6 X 10(-4)M) was spanned. Ca2+ was found to markedly inhibit pituitary AC and the mathematical analysis of data indicated the presence of two inhibition The two KiS were: 1.78 +/- 0.48 X 10(-7) M and 2.47 +/- 0.52 X 10(-4) M for the homogenates and 1.71 +/- 0.45 X 10(-7) M and 3.15 +/- 0.85 X 10(-4) M for the membrane preparations. No stimulation of the enzyme could be detected at any Ca2+ concentration tested. Furthermore, because of our experimental conditions it is unlikely that there was substantial loss of endogenous calmodulin, or other calcium binding protein(s) required to mediate AC stimulation by calcium. The lack of a calcium-calmodulin stimulation of pituitary AC was confirmed by experiments with anticalmodulin drugs (trifluoperazine and calmidazolium, R24571) and experiments with EGTA-washed membranes in the presence of exogenous calmodulin. At any Ca2+ concentration, the same AC activity was observed in the presence and in the absence of anticalmodulin drugs or added calmodulin. The mechanism of pituitary AC inhibition by Ca2+ was investigated focusing on a range of Ca2+ concentrations near the Ki for the high affinity calcium site and thus similar to the intracellular Ca2+ concentrations. Ca2+ was found to act as a competitive inhibitor of the Mg2+ activation of AC and as a noncompetitive inhibitor with respect to the MgATP2-, the substrate of the enzyme. The effects of Ca2+ on AC were also studied in cell populations and tissues extremely rich in PRL-secreting cells (cell fractions purified from rat anterior pituitaries and human prolactinomas). The pattern of Ca2+ action was found to be nearly superimposable on that observed in total pituitary.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenosine Triphosphate↗
PubMed1987

Sciatic nerve ATPase activity is unaffected in diabetic mutant C57Bl/Ks (db/db) mice.

We investigated composite (total), Mg2+-(ouabain-resistant), and Na+-K+-(ouabain-inhibited) ATPase in sciatic nerves of diabetic mutant C57Bl/Ks (db/db) and age-related littermate (db/+) control mice at various ages (16, 26, and 40 wk). This is the first report indicating that nerve ATPase activities measured in vitro showed no deficit in mice with spontaneous diabetes. Thus, diabetic neuropathy in the genetically diabetic mouse may occur in the absence of Na+-K+-ATPase abnormalities, which were previously described in association with polyol pathway impairment in experimental diabetic and BB Wistar rats. Control and diabetic groups treated with ganglioside mixture for 30 days before death presented statistically insignificant differences. Therefore, the beneficial effect of gangliosides described in C57Bl/Ks (db/db) mice on electrophysiological and morphometrical parameters must be due to different pharmacological activities rather than to prevention of the decay or better maintenance of ATPase activity.

Adenosine Triphosphatases↗
PubMed1987

The cytoarchitecture of the nucleus cuneiformis. A Nissl and Golgi study.

This investigation attempts to clarify the cytoarchitectural organisation of the neurons of the nucleus cuneiformis, a reticular nucleus of the midbrain particularly involved in locomotor activities. The study was carried out on the cat and man, in Nissl and Golgi material. The nerve cell bodies, which are small or medium sized, have a light basophilic cytoplasm and a large light nucleus usually containing one nucleolus. In Golgi material multipolar and fusiform cells can be identified. Multipolar cells, which form the majority of the neural population, have 3-7 primary spiny dendrites and an axon which often projects outside the nucleus. Fusiform cells have one or two primary dendrites endowed with spines, which are, however, less numerous than those of multipolar neurons. The axons generally end inside the nucleus. The main difference between man and the cat seems to be in the length and width of the neuronal arborisation, which are considerably greater in the former species. The characteristics of the two neuronal types suggest a projective function of the multipolar elements, but an interneuronal activity of the fusiform ones. The data support the similarity already found at the ultrastructural level between the nucleus cuneiformis and the periaqueductal grey matter, but on the other hand confirm the lesser degree of cytoarchitectural complexity of the nucleus.

Adult↗
PubMed1987

Ultrastructural study of the nucleus Cuneiformis in the cat.

The Cuneiformis nucleus (Cu.n.) is a reticular nucleus of the mesencephalic tegmentum which is involved in several functions and particularly in locomotor activities. While the physiological properties and the nervous connections of the nucleus have been studied, there is no data about its ultrastructure. Therefore, we investigated this region in cat at the electron microscope and with morphoquantitative methods to clarify its ultrastructural organization and particularly the characteristics of its synaptic complex. The neurons are small and medium in size, with a high nucleo-cytoplasmic ratio and a modest rough endoplasmic reticulum organization. The neuropil is very extensive. Myelinated axons are very numerous. Dendritic profiles whose plasmalemma is almost completely covered by synaptic boutons are observed frequently. There are few somatic synapses; 81% have symmetrical junctions and 23% have round vesicles only. There are numerous synapses in the neuropil, 40% having asymmetrical junctions and 60% containing round vesicles only. The greater functional complexity indicated by the morphological data and the greater extension of the neuropil synapses with respect to that of the somatic ones, suggest that the neuropil is the main site of modulation and integration of the inputs to the nucleus. A highly significant statistical difference between the sizes of the somatic vesicles and those of the neuropil was found. This may point to the presence of distinct populations of vesicles, which may be correlated with the variety of substances (neurotransmitters, neuropeptides etc ...) found in the nucleus. The remarkable ultrastructural similarity between the Cu.n. and the periaqueductal gray matter is discussed.

Animals↗
PubMed1986

In vivo treatment with GM1 prevents the rapid decay of ATPase activities and mitochondrial damage in hippocampal slices.

Slices from rat CA3 hippocampal area show a 30% decrement in ATPase activity after 35 min of 'in vitro' incubation. Such a drop is accompanied by an alteration of mitochondrial ultrastructure. However, if rats are treated daily with GM1 ganglioside (10 mg/kg during 3 days) both phenomena are fully prevented. These results would suggest a protective effect of gangliosides onto membrane structures under stress conditions.

Adenosine Triphosphatases↗
PubMed1986

The nucleus of Darkschewitsch in the cat: a Nissl, Golgi, and electron microscope analysis.

A light and electron microscope study was carried out to elucidate the cytoarchitectural organization of the nucleus of Darkschewitsch (ND) in the cat. From the anatomical staining methods, including Nissl and Golgi-Cox, it appears that the ND shows a clear heterogeneity of shape and size of the neuronal population. The small or medium-sized neurons show a high nuclear/cytoplasmic ratio and a modest basophilia. Spiny extrusions are present on many of the neurons, arranged either as varicosities giving a rosary feature or clumped in small groups over the dendritic processes; these are absent at the level of the soma. From the electron microscope analysis it appears that the neuropil is not very extensive because the neuronal bodies are numerous and compact. The synaptic complex is extensive both at the level of the nerve cell bodies and at the level of the neuropil. Since many of the synapses display the features typical of the inhibitory synapses, it is possible that they represent the anatomical basis of an inhibitory integrative function.

Animals↗
PubMed1986

Impaired axonal transport of acetylcholinesterase in the sciatic nerve of alloxan-diabetic rats: effect of ganglioside treatment.

The anterograde and retrograde axonal flow of acetylcholinesterase were studied in the sciatic nerve of alloxan-diabetic rats after five weeks of experimental diabetes. A slight reduction of the anterograde axonal flow of the enzyme was found in alloxan-diabetic compared to control rats. Sedimentation analysis revealed a major reduction of anterograde axonal flow of the light globular forms of the enzyme (G1 + G2), which are probably conveyed by slow transport. There was also a minor reduction of the anterograde flow of the globular form G4, while no modification of the axonal flow of the heavy asymmetric form A12 was found. Both G4 and A12 molecular forms are conveyed by fast axonal transport. In contrast, no abnormality of the retrograde axonal flow of acetylcholinesterase was observed. Ganglioside treatment antagonized the decline of the anterograde axonal flow of the enzyme in alloxan-diabetic rats. These results are consistent with the view that experimental diabetic neuropathy is associated with axonal transport defects, and suggest a protective effect of ganglioside treatment against neuronal damage(s) related to the diabetic syndrome.

Acetylcholinesterase↗
PubMed1986

[Not Available].

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History, Early Modern 1451-1600↗
PubMed1986

Combined evaluation of some tumor associated antigens in the monitoring of integrated surgical and chemotherapeutic treatment of epithelial ovarian cancer.

The authors measured the presurgical serum levels of some tumor associated antigens in 36 patients bearing primitive ovarian carcinoma and in 284 controls. Ca125, which has shown a sensitivity (SE) of 63.8% and a specificity (SP) of 92.6%, was elevated especially in serous and undifferentiated carcinomas, while Ca19-9 (SE = 33.3% and SP = 89.7%) and CEA (SE = 19.4% and SP = 96.4%) were more often pathological in mucinous ones. TPA (SE = 75.0% and SP = 81.3%) had no particular correlation with any histotype. Parallel assessment of Ca125 and Ca19-9 showed a SE = 83.3% and a SP = 83.8%. In patients with epithelial ovarian cancer, the circulating concentrations of tumor markers were periodically measured during and after chemotherapy. Ca125 levels correlated with the course of disease in 87.1% of instances, while Ca19-9 ones correlated in 72.2% and TPA ones in 78.6%. Constantly high concentrations of one or more markers during chemotherapy are indicative for unresponsiveness of cancer to cytostatic drugs. Serum levels of one or more tumor antigens elevated at diagnosis and in the normal range at the end of primary treatment can be associated both with a pathological complete regression and with a persistence of neoplastic disease at second look laparotomy. Considering the different sensitivity of every single marker in carcinomas of different histotype, the combined evaluation of multiple tumor associated antigens seems to offer the best information in the monitoring of epithelial ovarian cancer.

Adult↗
PubMed1985

A quantitative electron microscope study of the perikaryal projections of sensory ganglion neurons. II. Gecko and lizard.

The perikaryal projections of the neurons in the thoracic spinal ganglia of gecko and lizard usually appear as finger-shaped evaginations running roughly parallel to the surface of the nerve cell body; they show a nearly circular cross section with a rather uniform transverse diameter having an average value of about 0.2 micron. In both gecko and lizard a very high correlation was found between the surface area of perikaryal projections and both the volume and smoothed surface area of the corresponding nerve cell body. The results of the present research agree with those obtained in a previous study on two mammal species (cat and rabbit) and lend further support to the hypothesis advanced in that study; i.e., that perikaryal projections in sensory ganglion neurons are normal formations which maintain the surface-to-volume ratio above the critical level for metabolic exchanges. Perikaryal projections increase the surface area of the nerve cell body by 32.5% in gecko and 30% in lizard, while they increase it by 43% in cat and 39.5% in rabbit. This difference may be related to the lower metabolic rate of the neurons in poikilotherms than in mammals.

Animals↗
PubMed1985

Adoptive immunotherapy of intracerebral murine lymphomas: role of different lymphoid populations.

In an attempt to elucidate the cellular mechanisms responsible for the therapeutic activity of systemic immunotherapy in an adoptive transfer system, lymphoma cells were implanted i.c. It was found that, upon peripheral injection of cytotoxic T-lymphocytes with specificity for the tumor, the cells reached and infiltrated the diseased brain but did not accumulate selectively in the malignant graft. In order to accomplish significant tumor inhibition, the infused lymphocytes, largely expressing the Lyt-1+2+ phenotype, apparently cooperated with radioresistant phagocytic cells present in histocompatible hosts and athymic mice.

Animals↗
PubMed1985

Quantitative and comparative stress analysis in human femur under two different static situations by three-dimensional photoelasticity.

Using the three-dimensional photoelastic method a quantitative analysis was carried out on the tension trends in the proximal third of a normal human femur in a stationary weight-bearing situation on two legs. The results obtained show that in this loading situation the maximum stress values (both for tension and compression) are in the area just below the subtrochanteric zone; while going up along the borders of the diaphysis, the tension trends do not vary appreciably. Moreover, the state of the stresses is not constant but varies slightly along the thickness of the bone. The neutral axis is considerably displaced towards the tensile area. A comparison between the stress tension trends in two different static loading situations (one-leg and two-leg support) was carried out. It was found that the maximum tensile stress value in the one-leg position was about 24 times greater than that in the two-leg position and the maximum compression stress value was about 14 times greater than in the two-leg situation.

Birefringence↗
PubMed1985

A Golgi study of the periaqueductal gray matter in the cat. Neuronal types and their distribution.

In Golgi material, the neurons of the periaqueductal gray matter (PAG) of the cat have been classified into five types, according to the following criteria: number of dendrites per cell, characteristics of secondary arborization, frequency of spines and axon caliber. Type 1 cells, which are multipolar and rich in spines are the most frequent, and are probably intranuclear neurons. Type 4 cells have a short axon which ends in the PAG, but they differ from Type 1 in that their dendritic ramification is of a different type and there are few spines. Type 2 and 3 neurons have a thick axon which runs outside the PAG, and dendrites rich in spines. Type 2 cells have more primary dendrites, while Type 3 neurons have dendrites which may spread outside the PAG. Type 5 cells have dendrites with few spines and no secondary ramification. Their thick and long axon projects outside the PAG. Type 2, 3 and 5 cells have been considered projective neurons. The various neuron types are present in every area of the PAG, although in the ventral region there is a predominance of Type 2 and 5 neurons, in the dorsal regions of Type 2 and 3 cells, and in lateral regions of Type 3 and 5 cells. Local intrinsic circuits have been observed in which both the interneurons and the projective, with early axonic collaterals, are involved. The prevalence of neurons to which an afferent role has been attributed (Type 2 and 3 cells) compared with efferent cells (Type 5), is in agreement with hodological studies which indicate that the PAG receives multiple and numerous afferents in comparison with the relatively scarce efferent fibers. These projections can be intensely and deeply elaborated and modulated by means of local intrinsic circuits.

Animals↗
PubMed1985

Effect of insulin on neonatal and adult adrenal medulla in the rat.

The effect of equivalent doses of insulin on the adrenal of both adult and neonatal rats was compared. Glycemia in treated adults dropped to one third of the control, in contrast to the neonatal rat values, which decreased to about one half. After insulin, a large percentage of adult chromaffin cells showed cytoplasmic degranulation and vacuolization. In contrast, a smaller percentage of cytoplasmic changes was seen in the adrenal cells of 4- and 7-day-old rats. In rats of 10 days of age, the percentage of modified cells was similar to the adults. The morphological changes in neonatal medullae were characterized by widening of the perigranular space and enlargement of the endoplasmic reticulum cisternae. No cytoplasmic vacuolization was seen. This response of neonatal rats to insulin may indicate immaturity of the adrenal chromaffin tissue and/or of the centers involved in the mechanism of hypoglycemia-catecholamine release.

Adrenal Medulla↗