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Biomedical subjects

C Bianchi

Publications and source records attributed to C Bianchi.

At least 271 records · Page 15Linked to original sources
PubMed1988

Inversion of the alpha-2 and alpha-1 noradrenergic control of the cortical release of acetylcholine and gamma-aminobutyric acid in morphine-tolerant guinea pigs.

In normal guinea pigs the adrenergic agonists clonidine and norepinephrine are known to inhibit directly the cortical outflow of acetylcholine (ACh) through alpha-2 receptors and to increase the cortical outflow of gamma-aminobutyric acid (GABA) through alpha-1 receptors. GABA, in turn, contributes to inhibit ACh through GABAA receptors. This scheme is changed drastically by morphine tolerance. In morphine-tolerant guinea pigs, clonidine at 7.5, 18.7 and 112 nmol/kg i.p. stimulates the cortical release of ACh through alpha-1 receptors. This effect is prevented by prazosin, 35.8 nmol/kg i.p. Clonidine reduces ACh release at high doses only (374 and 1122 nmol/kg i.p.). Furthermore, electrical stimulation of locus ceruleus also gives rise to a prazosin-sensitive increase in ACh release. In addition, locus ceruleus stimulation often causes behavioral activation rather than sedation. In morphine-tolerant guinea pigs, clonidine at 7.5 and 18.7 nmol/kg i.p. reduces GABA efflux through alpha-2 receptors, as the drug effect is prevented by idazoxan, 84 nmol/kg i.p. Clonidine increases GABA efflux at high doses only (112 and 374 nmol/kg i.p.). Locus ceruleus stimulation also gives rise to an idazoxan-sensitive reduction in GABA outflow. This new condition, evident after 7 days of morphine treatment, can be defined as inversion of the physiological norepinephrine control over ACh and GABA outflow and can represent a major part of the neurochemical derangement associated with opioid tolerance.

Acetylcholine↗
PubMed1988

[Postoperative external biliary fistulas: personal case series].

Over the period 1974-1986, five patients with external biliary fistulas were admitted to our clinic. The fistulas set in as complications of surgical operations due in 3 cases to a Kehr drainage of the common bile duct, in 1 case to drainage of a subhepatic abscess and in 1 case to pancreatic hydatid cyst. The causes of onset of the fistulas are reported as well as the therapy adopted in each case.

Biliary Fistula↗
PubMed1987

Isolated glucocorticoid deficiency.

A three-month-old boy with hypoglycemic episodes, feeding problems and hyperpigmentation is described. Hormone assays revealed elevated serum ACTH values and low levels of plasma cortisol that did not rise after exogenous ACTH administration; blood pressure, serum electrolytes and earlier plasma aldosterone and renin activity were in the normal range. These data suggest a diagnosis of an isolated glucocorticoid deficiency, secondary to unresponsiveness to ACTH. Replacement therapy with glucocorticoids was highly effective. Despite replacement therapy, during follow-up he had an increase in basal plasma renin activity with aldosterone concentration normal. In our patient, a mineralcorticoid deficiency might eventually develop; therefore, the selective glucocorticoid deficiency might also be part of a progressive defect involving the glomerulosa too.

Aldosterone↗
PubMed1987

Effect of adriamycin on electron transport in rat heart, liver, and tumor mitochondria.

The effect of Adriamycin on mitochondria of the rat heart, liver, and Ehrlich ascites tumor mitochondria has been evaluated. The results may be summarized as follows: Adriamycin reduces both ADP- and FCCP-stimulated respiration, inhibits oxidative phosphorylation, decreases mitochondrial ATP-ase activity, and affects the redox state of respiratory carriers. These alterations are common to all types of mitochondria tested with almost similar patterns. However, the severe cardiotoxicity of the drug cannot be ascribed only to an effect on mitochondrial energy-yielding processes. The addition of hexokinase to phosphorylating heart mitochondria does not increase the sensitivity of succinate oxidation to Adriamycin. Experiments to determine the site of action were not able to detect a specific point of attack. It is conceivable, therefore, that the modifications induced by Adriamycin on the functional parameters of mitochondria may be ascribed to alterations of the physical state of some components of the inner mitochondrial membrane, e.g., lipids, which regulate the kinetic properties of the membrane-associated enzymes.

Animals↗
PubMed1987

A simple integrator to process the electroencephalogram of small laboratory animals.

A simple integrator to process the EEG of small laboratory animals is described. This device simultaneously integrates, at fixed short intervals, average wave frequency (SF) and wave area (SA, in microV X sec), assumed as a simplified index of the actual EEG power. From these values the average wave area, SA/SF, i.e., the quantal component of SA is calculated. By measuring the average wave frequency and by calculating SA/SF, different conditions, such as arousal reaction, drug-induced EEG activation, seizures, and anesthesia can be easily distinguished and quantified. Moreover, this approach allows one to correlate the fundamental EEG parameters (wave frequency and SA/SF) with neurochemical signs of brain activity, such as the release of neurotransmitters from the brain. Thus, a more complete knowledge of the pharmacological profile of neuroactive compounds is made possible.

Acoustic Stimulation↗
PubMed1987

Localization of 125I-atrial natriuretic factor (ANF)-binding sites in rat renal medulla. A light and electron microscope autoradiographic study.

Using light and electron microscope autoradiography in vivo, the localization of 125I-(Arg 101-Tyr 126) atrial natriuretic factor (ANF)-binding sites was studied in the renal medulla of rats. At the light microscopic level, the autoradiographic reaction was mainly distributed in patches in the outer medulla, and followed the tubular architecture in the innermost part of the inner medulla. At the electron microscopic level, binding sites were mainly found in the outer medullary descending vasa recta and inner medullary collecting ducts. These results suggest that, in rats, the renal medulla may participate in the natriuresis and diuresis produced by ANF through vascular and tubular effects; the former by changing medullary blood flow at the level of descending vasa recta and the latter by acting on electrolyte and water transport at the level of collecting ducts.

Animals↗
PubMed1987

Efficacy and tolerance of ceftazidime in the treatment of post-operative respiratory tract infections.

Ceftazidime proved particularly effective in the treatment of acute respiratory tract infections arising in the immediate post-operative period, affording complete clinical cures in 88.8% of cases and a substantial improvement in the pathological picture in the other 11.2% of cases treated. The authors also draw attention to the excellent tolerance of the antibiotic, as evaluated on the basis of liver and kidney function and blood chemistry parameters and the total absence of adverse reactions.

Adult↗
PubMed1987

[Cutaneous metastasis of a cloacogenic tumor].

A case of cloacogenic carcinoma with cutaneous metastases in a 74 year old man is reported. The patient presented with a six months history of two polyps of the lowest portion of the anal canal. Physical examination of the inguino-scrotal area revealed a 5 X 7 cm. hard infiltrative plaque with three ulcero-vegetative scars. Histologic examination of both polyps revealed two of the four cytologic patterns described in this neoplasm. One polyp showed undifferentiated cells, type IV and second one, type II differentiated. The biopsy of the cutaneous metastases showed dermal infiltrative clusters of the cytologic type II differentiated epidermal cells. Treatment with radiotherapy and chemotherapy was ineffective. Cloacogenic carcinoma of the canal anal is a transitional cells neoplasm believed to arise from vestigial remnants of cloacal origin. Metastases occurred in 19% of cases but cutaneous colonization develops exceptionally.

Aged↗
PubMed1987

Azthreonam in the treatment of urinary tract infection: evaluation of efficacy, renal effects and nephrotoxicity.

The efficacy, renal effects and nephrotoxicity of a short course of treatment with azthreonam were evaluated in 11 adult patients with urinary tract infection. Azthreonam was administered for 5 days at a daily dose adjusted to the residual renal function of the patients. In the pre-treatment period, during treatment and 10 days after completion of therapy, urine cultures, urinalysis and routine renal function tests (clearance of creatinine, urea and uric acid) were performed and urinary enzymes (alanine-aminopeptidase, gamma-glutamyl-transpeptidase, N-acetyl-beta-D-glucosaminidase, lysozyme) were determined. Renal haemodynamics (glomerular filtration rate and effective renal plasma flow) were measured in the pretreatment period and on the 5th day of therapy. The results confirm the efficacy of azthreonam for treatment of urinary tract infection. Results of renal function tests and measurements of urinary enzymes remained unchanged during and after treatment with azthreonam. These data support the conclusion that azthreonam is an effective antimicrobial agent which does not influence renal function or cause nephrotoxic effects.

Adult↗