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Biomedical subjects

C Messa

Publications and source records attributed to C Messa.

At least 73 records · Page 4Linked to original sources
PubMed1993

Bone metabolic activity measured with positron emission tomography and [18F]fluoride ion in renal osteodystrophy: correlation with bone histomorphometry.

We evaluated the bone metabolic activity in patients with renal osteodystrophy using positron emission tomography and [18F]fluoride ion. Eight patients had secondary hyperparathyroidism (HPT), and three had low-turnover bone disease. Eleven normal subjects were also studied, and three of the eight HPT patients were reevaluated after therapy. A rate constant (K) describing the net transport of [18F] fluoride ion into a bound compartment in bone was calculated using both a three-compartment model and Patlak graphical analysis. Values of K were compared with biochemical data and with histomorphometric indices. The results indicate that K is significantly higher (P < 0.01) in HPT patients than in normal subjects and patients with low-turnover bone disease. Values of K correlated with serum alkaline phosphatase (r = 0.81) and PTH (r = 0.93) levels and with histomorphometric indices of bone formation rate (r = 0.84, P < 0.01) and eroded perimeter (r = 0.77, P < 0.05). Values of K decreased by 40 and 30%, respectively, in two patients who underwent parathyroidectomy and medical therapy. Positron emission tomography studies of bone using [18F]fluoride ion can differentiate low turnover from high turnover lesions of renal osteodystrophy and provide quantitative estimates of bone cell activity that correlate with histomorphometric data.

Adolescent↗
PubMed1993

[Serum lipids and biliary sludge during pregnancy].

We have examined serum lipids and apoprotein levels and the formation of biliary sludge in 56 pregnant women. During pregnancy, 8 women showed biliary sludge which disappeared after delivery. Pregnant women with sludge had serum levels of total cholesterol, triglycerides, LDL-cholesterol and apo-B higher than women without sludge, although it was not statistically significant. Moreover, these women had serum levels of HDL-cholesterol and apoA1 significantly lower and LDL/HDL and apoB/apoA1 ratio significantly higher than the women without sludge. Thus, biliary sludge seems to be associated with serum lipid and apoprotein variations. Further investigations are required to clarify if these variations are also expressed in the bile.

Adult↗
PubMed1993

Endogenous sex hormones and cholesterol gallstones: a case-control study in an echographic survey of gallstones.

In a population survey of gallstones, the serum levels of hormones of the pituitary-gonadal axis and the sex hormone-binding globulin (SHBG) were compared in subjects with cholesterol gallstones and in a control group. In 84 subjects who entered the survey, echographic gallstones that had been identified at the survey, turned out to be radiolucent or mixed (predominantly of cholesterol) at subsequent x-ray. The controls were without gallstones at echography, matched to the cases for potential confounders of the association sex hormones-cholelithiasis. Testosterone (T) 17-beta-estradiol (E2), 17-OH progesterone (P), and SHBG were dosed by radioimmunoassay; follicle-stimulating hormone (FSH), luteinizing hormone (LH), and prolactin (Prl) by dissociation-enhanced lanthanide fluoro immunoassay (DELFIA). Men with gallstones had lower LH than controls (n = 34, median difference = -0.62 mU/ml, 95% confidence interval (CI) -1.20 to -0.26 mU/ml, paired sign test, p = 0.003). Premenopausal women in the luteal phase of the menstrual cycle with gallstones had higher E2 than controls (n = 7, median difference: +117, pg/ml, 95% CI: +10 to +218 pg/ml, p = 0.008). Postmenopausal women had lower LH than controls (n = 35, median difference = -4.57 mU/ml, 95% CI -9.5 to -1.0 mU/ml, p = 0.04). No other hormones showed statistically significant differences between cases and controls, in either males or females. The findings of this exploratory study in subjects with radiolucent and mixed gallstones suggest that men and postmenopausal women have lower LH, and premenopausal women in the luteal phase of the cycle have higher E2, than controls.

Adult↗
PubMed1992

Sex steroid hormone receptors, epidermal growth factor receptor, and polyamines in human colorectal cancer.

We assayed the estrogen and progesterone cytosolic receptors by using the enzyme immunoassay method, the epidermal growth factor (EGF) cell surface receptors by using 125I-labeled hormone, and the levels of polyamines (putrescine, spermine, and spermidine) by using a high-pressure liquid chromatography (HPLC) procedure in neoplastic and surrounding normal tissues of patients with colorectal cancer. Our findings show that mean polyamine levels in neoplastic tissue were approximately two-fold greater than the levels in normal colonic mucosa. Estrogen and progesterone receptorial content in normal mucosa were twofold greater than those in neoplastic tissue. No significant differences in EGF receptors were found between colonic cancer tissue and the surrounding normal tissues. The correlations we found between 1) estrogen and polyamine levels and 2) estrogen and EGF binding suggest the existence of a modulation of the estrogens on colonic mucosa cell proliferation. Furthermore, there was no significant dependency of polyamine and receptor concentrations from the tumor site, the histologic differentiation, or the age and sex of patients.

Adult↗
PubMed1992

The role of positron emission tomography in oncology and other whole-body applications.

Imaging and quantifying biochemical and physiological processes with PET clearly has major potential significance for all organ systems and many disease states. Although the full utility and potential of emerging new applications of PET in organs other than the heart and brain must be demonstrated in basic and clinical research studies, the rapidly accumulating aggregate experience in oncology in particular, and in other organ systems and disease states as well, indicates that PET is now truly becoming a modality of both clinical and investigative use for the body as a whole as well as for specific organ systems. Whole-body PET FDG imaging (Fig 9) illustrates the potential of biochemical imaging to map the distribution of cancer throughout the body. With the growing list of radiopharmaceutical and quantitative techniques applicable to cancer studies with PET, this field will continue to realize significant growth.

Humans↗
PubMed1992

Errors introduced by tissue heterogeneity in estimation of local cerebral glucose utilization with current kinetic models of the [18F]fluorodeoxyglucose method.

The effects of tissue heterogeneity on the estimation of regional cerebral glucose utilization (rCMRglc) in normal humans with [18F]2-fluoro-2-deoxy-D-glucose ([18F]FDG) and positron emission tomography (PET) were compared with respect to the various kinetic models of the [18F]FDG method. The kinetic models were conventional homogeneous tissue models of the [18F]FDG method, with (4K Model) and without (3K Model) a rate constant to account for an apparent loss of [18F]2-fluoro-2-deoxy-D-glucose-6-phosphate ([18F]FDG-6-P), and a tissue heterogeneity model (TH Model). When either of the kinetic models designed for homogeneous tissues was applied to heterogeneous tissues, estimates of the rate constant for efflux of [18F]FDG from the tissue (k2*) and of the rate constant for phosphorylation of [18F]FDG (k3*) decreased as the duration of the experimental period was increased. When the 4K Model was used, estimates of the rate constant for the apparent dephosphorylation of [18F]FDG-6-P (k4*) were significantly greater than zero and fell with increasing duration of the experimental period. Although the TH Model included no term to describe an apparent dephosphorylation of [18F]FDG-6-P, the fit of the TH Model to the time course of total tissue radioactivity was at least as good as and often better than the fit of the 4K Model in the 120-min period following the pulse of [18F]FDG. Hence, the high estimates of k4* found in PET studies of less than or equal to 120 min can be explained as the consequence of measuring radioactivity in a heterogeneous tissue and applying a model designed for a homogeneous tissue; there remains no evidence of significant dephosphorylation of [18F]FDG-6-P in this time period. Furthermore, use of the 4K Model led to an overestimation of rCMRglc; whole-brain glucose utilization calculated with the 4K Model was greater than 20% higher than values usually obtained in normal humans by the model-independent Kety-Schmidt technique. rCMRglc was accurately estimated by the TH Model and, in experimental periods sufficiently long to minimize the effects of tissue heterogeneity, also by the original 3K Model of the deoxyglucose method.

Adult↗
PubMed1992

[Cholecystectomy and duodenogastric reflux].

With the aim of evaluating whether cholecystectomy causes an increase in duodenogastric reflux (DGR) 34 patient (12 males and 22 females, mean age 50 years) were examined before and 6 months after cholecystectomy. DGR was evaluated by assaying total and individual biliary acids in gastric juice and was expressed as fasting bile reflux (FBR) in mumol/h. The histology of gastric mucosa in endoscopic biopsies taken from the antrum and body was also analysed. FBR of total biliary acids rose from 2.4 mumol/h before surgery to 41.33 mumol/h after cholecystectomy (p = 0.000). A significant increase was observed for all the individual biliary acids. Histological tests of gastric mucosa revealed an increased percentage of chronic atrophic gastritis of the antrum following cholecystectomy. Histological conditions in the body were unaltered. The results of this study show that there is a significant increase in DGR (months after cholecystectomy together with increased histological damage to the mucosa of the antrum. Further studies are necessary in order to evaluate whether the two phenomena are related.

Adult↗
PubMed1992

A prospective study on duodenogastric reflux and on histological changes in gastric mucosa after cholecystectomy.

The authors carried out a prospective study to evaluate variations with time in postcholecystectomy duodenogastric reflux (expressed as "fasting bile reflux" in mumol/h) and in gastric mucosal damage. Ten patients underwent (before cholecystectomy, 6 months after surgery and after a median period of 4 years from surgery) a gastric drainage to assess total (enzymatic method) and single (high performance liquid chromatography) intragastric bile acids, and a gastroscopy with biopsies of the antrum and gastric body to assess histological damage to the mucosa. The results showed that there was a progressive increase in the fasting bile reflux of total bile acids with time (precholecystectomy median value 0.295 mumol/h; 6 months control median value 12.045 mumol/h; late control medial value 19.9 mumol/h; Friedman test, P = 0.0022). Examination of the gastric mucosa at the three moments of the study showed that histological damage worsened progressively. In fact chronic atrophic gastritis of the antrum was present in 10 percent of cases before surgery and in 50 percent 4 years after, and the prevalence of chronic superficial gastritis of the body progressed from 0 to 40 percent. Studies on larger groups of patients are necessary to evaluate whether these two phenomena are correlated.

Adult↗
PubMed1992

Polyamines and estrogen-receptor concentrations in human colorectal carcinomas.

We assayed the estrogen receptors and polyamine levels (putrescine, spermidine and spermine) in the neoplastic and "normal" surrounding tissue of patients with colorectal cancer. Polyamine levels and the spermidine/spermine ratio were significantly higher in the neoplastic tissue than in the "normal" surrounding colonic mucosa of the same patients. Estrogen receptors were fewer in neoplastic mucosa than in the surrounding tissue, and polyamine levels were higher in estrogen-receptor negative tumours than in estrogen-receptor positive ones, although this was statistically significant only in the case of spermidine. Polyamine levels and estrogen receptor concentrations did not correlate with the tumour site, histological differentiation, or the age and sex of patients.

Adenocarcinoma↗
PubMed1991

In vitro gallbladder motility in patients with radiolucent and radiopaque stones.

Twenty-five gallbladders were studied in vitro. Sixteen had radiolucent gallstones and 9 had radiopaque gallstones. The radiolucent gallstones had a cholesterol content of 94.17 +/- 3.76% and the radiopaque gallstones had a cholesterol content of 56.6 +/- 4.46%. Half the maximal response (ED50) to cholecystokinin octapeptide (CCK-OP) and to carbachol in strips from patients with radiolucent gallstones was 0.8 +/- 0.15 and 27.01 +/- 3.74 x 10(-7) M, respectively. In strips from patients with radiopaque gallstones, the ED50 was 0.4 +/- 0.08 and 14.92 +/- 3.07 x 10(-7) M, respectively. The ED50 values to CCK-OP and carbachol were greater in strips from specimens with radiolucent gallstones than in strips from specimens with radiopaque gallstones (p less than 0.05). There was no significant difference in the maximal contractile response of the two groups. It can be concluded that gallbladder sensitivity to CCK-OP and carbachol can be modified in relation to differences in the cholesterol and calcium content of the stones.

Adult↗
PubMed1991

Prevalence of pigment gallstones in sheep.

In a survey of 666 sheep at a slaughterhouse, gallstones (concretions with a diameter greater than or equal to 1 mm) were found in the gallbladder of 50 sheep (7.5%), sludge (concretions with a diameter less than 1 mm) was found in 9 sheep (1.4%), and sludge plus gallstones were found in 7 sheep (1.1%). Gallstones and sludge were associated, and were more frequent in lambs and females, compared with adults and males. Qualitative analysis of the stones revealed all to be pigment (bilirubin) stones. There was a statistically significant increase of biliary bilirubin (total and indirect quota) only in sheep with gallstones plus sludge, compared with control sheep without sludge or gallstones. Concentrations of bilirubin, cholesterol, phospholipids, total and single bile aids, and total and ionized calcium were similar in the bile of sheep with gallstones, sludge, or both and control sheep. Bacteriologic analysis of the bile in 10 sheep with gallstones and 10 controls revealed bacteria in 50% of the first group and in 75% of the second group (Escherichia coli in all sheep and Salmonella spp also in 1 sheep with gallstones). These findings confirm our earlier findings of a high prevalence of black pigment gallstones in sheep. On that basis, we suggest that gallstones are associated with high total bilirubin concentration in the bile, and deconjugating bacteria are common in the biliary tract of these animals.

Animals↗
PubMed1990

Duodenogastric reflux of bile acids, gastrin and parietal cells, and gastric acid secretion before and 6 months after cholecystectomy.

In order to evaluate the effect of cholecystectomy on the gastric mucosa, the duodenogastric reflux of total and single bile acids, the number of parietal and gastrin cells, and the volume of gastric acid secretion were examined in 15 patients with gallstones and functioning gallbladders before and 6 months after cholecystectomy. The duodenogastric reflux of the total bile acids increased from a mean preoperative value of 1.9 mumol/hour to a mean postoperative value of 21 mumol/hour (p = 0.008). The duodenogastric reflux of all single bile acids increased after cholecystectomy, with a higher increase in glycoconjugated compared with tauroconjugated bile acids. The parietal cells decreased from a mean preoperative value of 82.8 to a mean postoperative value of 68.7 (p = 0.05), whereas there was only a mild increase in the number of gastrin cells; the output of gastric acid remained unchanged. The variation of the gastrin cells before and after cholecystectomy was negatively correlated only with the variation of taurocholic acid (r = -0.50, p = 0.05), while the variation of the parietal cells was mildly correlated with all single bile acids (r = 0.35-0.50, 0.05 less than p less than 0.02). These findings show an increased duodenogastric reflux of bile acids 6 months after cholecystectomy with a mild morphologic alteration of the gastric mucosa.

Adult↗
PubMed1990

Sex steroid hormone receptors and human gallbladder motility in vitro.

This study was designed to investigate the relationship between estrogen and progesterone receptor levels and in vitro contractile response of gallbladder muscle strips to stimulation by carbachol and cholecystokinin-octapeptide (CCK-OP). Seventeen female postmenopausal patients cholecystectomized for gallstones were studied. Samples of the gallbladder wall were used for histological examination; motility was studied by Keane et al. [Surg Gynecol Obstet 1986; 163:555-560]; the estrogen and progesterone receptor levels were evaluated by immunoenzymatic assay. Positive correlations were found between the progesterone receptor level and the carbachol concentration that produced half the maximal response (ED50), and between the estrogen receptor level and the ED50 of CCK-OP. Our data confirm the presence of estrogen and progesterone receptors in the gallbladder and suggest that sex steroid hormones act on gallbladder motility by modulating the affinity of gallbladder receptors to CCK-OP and carbachol.

Carbachol↗
PubMed1989

Cortical pathophysiology and clinical neurologic abnormalities in acute cerebral ischemia. A serial study with single photon emission computed tomography.

We studied brain cortical radioactive tracer activity in a consecutive series of nine patients with acute hemispheric ischemic stroke at their first cerebral ischemic stroke at their first cerebral ischemic episode. Results from N,N,N'-trimethyl-N'- (2-hydroxy-3-methyl-5-[123-I]-iodobenzyl)-1,3 propanediamine-2HCl (four patients) and technetium Tc 99m hexamethylpropyleneamine oxime (five patients) single photon emission computed tomographic studies were compared with x-ray computed tomography (CT) and clinical findings within the first 48 hours, on day 10, and on day 30 after the clinical ictus. Cortical hypoactivity agreeing with the clinical findings was found on all initial scans but not in the follow-up studies. Cortical activity on the affected side in patients with stroke was significantly lower when compared with cortical activity in sex- and age-matched controls (n = 21). Computed tomography (with contrast) was less sensitive in detecting the ischemic lesions. These studies demonstrate that in the acute phase of stroke there is a single photon emission computed tomographic cortical disturbance that agrees with clinical findings, even when computed tomography scan infarction is limited to subcortical structures.

Adult↗
PubMed1989

Serum and bile lipid levels in a postmenopausal woman after percutaneous and oral natural estrogens.

17 beta-Estradiol was administered for 4 weeks percutaneously (5 mg/day) and, after a 6-week period to allow the drug to wash out, orally (2 mg/day) to a postmenopausal woman in whom a Kerr tube had been placed because of an iatrogenic lesion of the common bile duct. After both methods of administration, there was an increase in the biliary cholesterol concentration, but after oral administration, bile flow also increased and cholesterol crystals appeared in the bile. The percutaneous method of estradiol administration in postmenopausal women seems to be less dangerous for the biliary tract.

Administration, Cutaneous↗
PubMed1988

Spontaneous cholelithiasis in sheep: prevalence survey and analysis of gallstones and bile.

In an abattoir survey of the consecutive series of 206 sheep at a local slaughterhouse, gallstones (concretions with a diameter equal to or greater than 1 mm) were found in the gall bladder of 24 animals. There were stones in 19 out of 146 adult sheep and in 5 out of 60 lambs, with the higher frequency in the male sex in both groups. Qualitative analysis of the stones showed that all of them were pigment (bilirubin) stones. There was no statistically significant difference (paired t test, P greater than 0.05) between the amounts of biliary cholesterol, phospholipids, bile acids and total and indirect bilirubin in 12 sheep with gallstones and 12 control sheep without gallstones, paired for age, sex and day of slaughter.

Age Factors↗