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Biomedical subjects

M Ronchi

Publications and source records attributed to M Ronchi.

27 records · Page 2Linked to original sources
PubMed1985

Correlation between fetal and maternal serum bile acid concentrations.

Serum concentrations of different bile acids (BA) were determined by radioimmunoassay in 56 human fetuses and mothers. Serum was obtained immediately after legal abortion, performed between the 14th and the 21st wk of gestation. Conjugated cholic (CCA) and chenodeoxycholic acid (CCDCA) concentrations were determined in 33 cases, conjugated lithocholic (CLCA) and deoxycholic acid (CDCA) in 20, and sulfolithocholyglycine (SLCG) in 15. In fetal blood, mean concentrations of CCA (0.80 +/- 0.40 mumol/liter), CCDCA (4.50 +/- 2.70 mumol/liter), and CLCA (1.70 +/- 1.04 mumol/liter) were significantly higher than those in the mother (CCA 0.34 +/- 0.17 mumol/liter; CCDCA 0.79 +/- 0.34 mumol/liter; CLCA: 0.70 +/- 0.30 mumol/liter; p less than 0.001); fetal serum levels of CDCA (0.46 +/- 0.32 mumol/liter) and SLCG (0.15 +/- 0.09 mumol/liter) were lower than in the mothers (CDCA 1.20 +/- 0.80 mumol/liter, p less than 0.001; SLCG 0.40 +/- 0.30 mumol/liter, p less than 0.01). There was no correlation between levels of BA and gestational age. Serum total protein and albumin concentrations were both reduced in 10 fetuses as compared with the mothers. These data support the concept of a state of physiologic cholestasis during development and suggest that placental transfer of primary BA occurs mostly in the fetal to maternal direction. This transfer could be facilitated by the reduced fetal plasma albumin concentration, since BA in free solution diffuse more easily through the placenta. There is evidence of lithocholic acid synthesis in the fetal liver, while deoxycholic acid appears to be mostly of maternal origin. Finally, sulfation of BA is poorly developed at this age of gestation.

Bile Acids and Salts↗
PubMedDate not supplied

Treatment of hepatic encephalopathy with non-absorbable antibiotics.

Hepatic encephalopathy represents a well known neuropsychiatric syndrome in patients with either acute or chronic impaired liver function and is characterized by disturbance of consciousness, personality and intellectual capacity, altered neuromuscular activity and electroencephalographic abnormalities. The pathogenesis of the syndrome is still unknown, although important roles are ascribed to circulating gut-derived toxins of nitrogenous origin and to changing in central neurotransmission. Therefore, treatment is aimed to reduce the production and absorption of gut-derived toxins and to modify central neurotransmission balance. Among the different therapeutic approaches proposed for the management of hepatic encephalopathy, antimicrobial agents, alone or in combination with non-absorbable disaccharides, represent an important step, being able to reduce the production and absorption of ammonia, a compound of key importance in the pathogenesis of hepatic encephalopathy.

Ampicillin↗
PubMedDate not supplied

The steatocrit: a simple method for monitoring fat malabsorption in patients with cystic fibrosis.

Steatocrit was determined through microcentrifugation of fecal homogenate from 110 pediatric controls and 107 patients with cystic fibrosis (CF). For 74 CF patients, steatocrit was determined in the same fecal material collected to determine a fat balance. In controls, steatocrit value was 0.7 +/- 1.0%, which was significantly lower than values found in CF patients with a coefficient of fat excretion less than 10% of intake (1.7 +/- 1.2%). Significantly increased values were found in CF patients with a coefficient of fat excretion ranging between 10 and 25% of intake (4.7 +/- 1.7%) and in those whose coefficient of fat excretion was greater than 25% of intake (11.3 +/- 4.3%). In the 74 CF patients, steatocrit was directly correlated to the coefficient of fat excretion (r = 0.93; P less than 0.001). We performed steatocrit several times in the course of the 1st year of life in 33 infants with CF diagnosed by means of CF screening. Values obtained at the time of diagnosis, before starting enzymatic therapy, were relatively high; they showed a progressive decrease when, using steatocrit as a guide, the dose of pancreatic enzymes had been increased. The normalization of steatocrit values was accompanied by a better growth rate in the majority of these infants, confirming the importance of an optimal early correction of pancreatic insufficiency. We propose that this simple semiquantitative test can be usefully performed for the frequent monitoring of fat absorption and for checking the response to enzymatic therapy in patients with CF.

Adolescent↗
PubMedDate not supplied

Circadian temporal structure in psoriasis.

The unknown etiopathogenesis of psoriasis and its often unpredictable course, in spite of actual treatment, suggest the search of parameters correlated with the disease that could help to better define and treat these patients. The altered cell turnover of the psoriatic epidermis leads to hypothesize a disturbance or at least a modification of the cellular rhythm of the skin. In order to prove alterations of the circadian temporal structure in psoriasis, we have studied some easily detectable variables, registered at 3-h intervals, in both psoriatic and in healthy control subjects. The control subjects presented statistically significant circadian rhythms of oral temperature, arterial blood pressure, pulse, electrolytes, 17KS, 17-OHCS and uricemia. In the psoriatic group, only a few of these variables present a clearly reproducible circadian rhythm. Moreover these rhythms, when they are demonstrable in the patients, do not show the same circadian acrophases of the control subjects and they are also desynchronized inside the group itself. The alteration in these circadian urinary and haematic rhythms implies that in psoriasis not only the skin is involved: all the circadian structure seems to be perturbed and the cause of the disease should mot be searched only in the epidermis.

17-Hydroxycorticosteroids↗
PubMedDate not supplied

Lipoperoxide plasma levels in patients with liver cirrhosis.

BACKGROUND/AIMS: Oxygen free radicals might play a role in the pathogenesis of tissue damage in many pathological conditions, including liver diseases where antioxidant tissue systems are reduced. The leading mechanism of free radical toxicity is the peroxidation of membrane phospholipids. Lipoperoxide hydrolysis produces aldehydes -the most represented being malondialdehyde-which reacts with thiobarbituric acid and whose concentration is considered a marker of lipid peroxidation. MATERIALS AND METHODS: We developed a fast and cheap HPLC method for measuring malondialdehyde concentration in plasma using a 3 mm C18 Baker column (4.6 x 50 mm). Thiobarbituric acid-reacting substances were eluted isocratically with a mobile phase containing methanol/KH2PO4 (35/65), and detected fluorometrically. The whole analysis lasts 2.5 minutes. The fasting levels of thiobarbituric acid-reactive substances were measured in 30 non-smoking blood donors and in 45 patients with liver cirrhosis. RESULTS: In control subjects they were on average 0.84 [SD 0.41] mumol/L and were increased to 1.59 [SD 1.23] mumol/L in patients with cirrhosis, where they inversely correlated with hepatocellular function. CONCLUSIONS: The method compares favorably with previous techniques in terms of cost and analytical time. It can be used for serial measurement of plasma lipoperoxide concentrations in response to oxidative stress or following drug administration. Our preliminary data confirms the presence of an oxidative stress in cirrhotic patients. Normal lipoperoxide levels in subjects with very advanced disease may be due to polyunsaturated fatty acid deficiency and/or enzyme defects.

Chromatography, High Pressure Liquid↗