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Biomedical subjects

G Castellani

Publications and source records attributed to G Castellani.

At least 19 recordsLinked to original sources
PubMed2005

Leptin concentrations in plasma and follicular fluid from prepubertal gilts as influenced by fasting, refeeding and insulin.

This study's aim was to examine whether fasting and refeeding would influence leptin levels in both plasma and follicular fluid from prepubertal gilts, and whether insulin affects leptin levels in fasting gilts. In experiment 1, four gilts were fasted for 72 h and then refed. Blood samples were withdrawn during normoalimentation, at the end of fasting, and for 4 h after refeeding. All samples were assayed for leptin; alternate samples were assayed for insulin, glucose and non-esterified fatty acids (NEFA). Fasting caused a decrease in leptin, glucose and insulin levels in plasma, while NEFA concentrations increased. In experiment 2, four gilts were given insulin as a bolus (0.2 IU/kg body weight) after 68 h of fasting. Blood samples were collected every 15 min around insulin administration and were assayed for leptin, insulin and glucose. This experiment shows that insulin administration increases leptin levels during fasting. In experiment 3, gilts were ovariectomized during normal alimentation (n=4), after 48 h of fasting (n=4), and after 48 h of realimentation following 48 h of fasting (n=4). Leptin levels in both plasma and follicular fluid collected after 48 h of fasting were significantly lower than those observed during normoalimentation or refeeding. In conclusion, a transient increase in insulin during fasting is effective in restoring leptin concentrations; in addition, leptin levels in follicular fluid parallel those in plasma.

Age Factors↗
PubMed2003

Cadmium, chromium and lead contamination of Athene noctua, the little owl, of Bologna and Parma, Italy.

A study was conducted to determine cadmium, chromium and lead concentrations in liver and brain of 52 little owls (Athene noctua) from two provinces of Emilia Romagna region, with the aim of furnishing indirect information concerning contamination of their habitat, also considering possible environmental dispersion of the metals. Metal analysis was performed by atomic absorption spectrophotometry with graphite furnace. Variance analysis with sampling area, gender and age shows that no statistical difference was found for gender, while a significant difference (P<0.05) was found for cadmium and lead, but not for chromium, when sampling areas and age were of concern. For all metals highest mean concentrations were found in liver (170 ppb for cadmium, 297 ppb for chromium and 312 ppb for lead). These levels can be considered as indicative of chronic exposure to low and "background" amounts of pollutants and they are of no toxicological concern, as they are always well below the toxic thresholds defined for each metal. The present study can be considered as a starting point for further analyses, aimed to the definition of any possible subtle effect (e.g. effects on enzymes activity) and of any possible correlation between levels of pollutants and appearance of possible adverse effects. It also furnished useful data for diagnostic cases and potentially for monitoring local contamination.

Animals↗
PubMed2001

Follicle activation involves vascular endothelial growth factor production and increased blood vessel extension.

The authors evaluated the relationship between vascular endothelial growth factor (VEGF) production, blood vessel extension, and steroidogenesis in small (<4 mm), medium (4-5 mm), and large (>5 mm) follicles isolated from gilts treated with eCG. VEGF and estradiol levels were measured in follicular fluid by an enzyme immunoassay and radioimmunoassay, respectively, and then each follicle wall was used to evaluate VEGF mRNA content and for the immunohistochemical analysis of blood vessels. VEGF production was low in small follicles (<3 ng/ml), high in large follicles (>10 ng/ml), and markedly differentiated in medium follicles; 44% exhibited values up to 15 ng/ml, whereas the levels never exceeded 3 ng/ml in the remaining aliquot. Medium follicles were then used as a model to investigate angiogenesis. Reverse transcription-polymerase chain reaction for VEGF mRNA demonstrated that granulosa cells represent the main component involved in the production of VEGF. The follicle wall, which presents two distinct concentric vessel networks, showed a vascular area (positive stained area/percent of field area) that was significantly wider in high VEGF follicles than in low VEGF follicles (2.54% +/- 0.58% vs. 1.29% +/- 0.58%, respectively). Medium follicles with high VEGF levels and extensive vascularization accumulated high estradiol levels (150-300 ng/ml), whereas follicles with low VEGF levels had basal estradiol levels that never exceeded 30 ng/ml. Early atretic medium-size follicles had undetectable levels of VEGF and estradiol paralleled by a marked reduction in blood vessel. The data presented propose an improved model for follicle dynamics in which the production of VEGF, stimulated by gonadotropin, creates the vascular conditions required for follicle growth and activity.

Animals↗
PubMed1999

Absorption kinetics and bioavailability of cephalexin in the dog after oral and intramuscular administration.

The pharmacokinetics of cephalexin, a first generation cephalosporin, were investigated in dogs using two formulations marketed for humans, but also often employed by practitioners for pet therapy. Cephalexin was administered to five dogs intravenously and intramuscularly as a sodium salt and by the oral route as a monohydrate. The dosage was always 20 mg/kg of active ingredient. A microbiological assay with Sarcina lutea as the test organism was adopted to measure cephalexin concentrations in serum. The mean residence time (MRT) median values after intravenous (i.v.), intramuscular (i.m.) and oral administration (p.o.) were 86 min, 200 min, and 279 min, respectively. After i.m. and oral dosing the peak serum concentrations (24.2 +/- 1.8 micrograms/mL and 20.3 +/- 1.7 micrograms/mL, respectively) were attained at 90 min in all dogs and bioavailabilities were 63 +/- 10% and 57 +/- 5%, respectively. The time course of the cephalexin serum concentrations after oral administration was best described by a model incorporating saturable absorption kinetics of the Michaelis-Menten type: thus in the gastrointestinal tract of dogs a carrier mediated transport for cephalexin similar to that reported in humans, may exist. The predicted average serum concentrations of cephalexin after repeated i.m. and oral administration indicated that, in order to maintain the therapeutic concentrations, the 20 mg/kg b.w. dosage should be administered every 6-8 h.

Absorption↗
PubMed1997

Phenotypic characteristics and tendency to apoptosis of peripheral blood mononuclear cells from HIV+ long term non progressors.

The aim of this study was to analyze (i) phenotype, (ii) in vitro spontaneous and induced apoptosis, (iii) glutathione (GSH) intracellular content and (iv) inhibitors of apoptosis of potential therapeutical use in peripheral blood mononuclear cells (PBMC) from HIV+ long term non progressors (LTNP), in comparison with progressors (HIV+P) and seronegative controls (HIV-). Three groups of subjects were studied: 15 HIV+P (patients losing >150 CD4+/year), 9 LTNP (subjects infected by HIV for at least 7 years without clinical and immunological signs of progression, with a mean of 898 CD4+/microL) and 18 HIV-. All subjects were living in a large community for former drug addicts, and were matched for age and sex. We used flow cytometry for analyzing PBMC phenotype and apoptosis; high performance liquid chromatography for measuring intracellular GSH content. PBMC phenotype of LTNP shared characteristics with those of both HIV- and HIV+P. Indeed, LTNP showed a normal number CD4+ cells (an inclusion criteria), but significantly increased numbers of CD8+ lymphocytes, activated T cells, CD19+, CD5+ B lymphocytes and CD57+ cells, as well as a decrease in CD19+, CD5- B lymphocytes and CD16+ cells. In LTNP, spontaneous apoptosis was similar to that of HIV- and significantly lower than that of HIV+P. Adding interleukin-2 (IL-2) or nicotinamide (NAM) significantly decreased spontaneous apoptosis in LTNP and HIV+P. Pokeweed mitogen-induced apoptosis was also similar in LTNP and HIV-, but significantly lower than that of HIV+P. In HIV+P, but also in LTNP, spontaneous apoptosis was inversely correlated to the absolute number and percentage of CD4+ cells and directly correlated to the number and percentage of activated T cells present in peripheral blood. GSH intracellular content was greatly decreased in PBMC from HIV+P and slightly, but significantly, reduced in LTNP. Adding 2-deoxy-D-ribose, an agent provoking apoptosis through GSH depletion, to quiescent PBMC resulted in similar levels of massive cell death in the three groups. This phenomenon was equally prevented in the three groups by N-acetyl-cysteine but not by IL-2. A complex immunological situation seems to occur in LTNP. Indeed, PBMC from LTNP are characterized by a normal in vitro tendency to undergo apoptosis despite the presence of a strong activation of their immune system, unexpectedly similar to that of HIV+P. Our data suggest that NAM and IL-2 are possible candidates for reducing spontaneous apoptosis in HIV infection.

Journal Article↗
PubMed1996

CD45 isoforms expression on CD4+ and CD8+ T cells throughout life, from newborns to centenarians: implications for T cell memory.

CD4+ and CD8+ peripheral blood T lymphocytes show mutually exclusive expression of CD45RA or CD45R0, two isoforms of the common leukocyte antigen that seem to recognize so-called virgin/unprimed and memory/activated T cells. The expression of these isoforms has been studied by three colour cytofluorimetric analysis on CD4+ or CD8+ peripheral blood CD3+ cells from 22 healthy centenarians, analyzed in a context of 202 healthy donors 0-110 years old. An age-related unbalance of virgin and memory cells was found between CD4+ and CD8+ subsets. As expected, at birgh 95-99% of the CD3+ lymphocytes expressed the CD45RA isoform. A rapid increase of CD45R0+ cells was observed in the first 2-3 decades of life, this phenomenon being much more pronounced on CD4+ cells. Subsequently, the increase of the 'memory' compartment was much less rapid, so that in centenarians a consistent reservoire of CD45RA+ among CD4+ cells was still present (about 20%). In these exceptional individuals the percentage of CD45RA+ cells among CD8+ T lymphocytes was even higher (about 50%), and only slightly lower than that of young donors (about 55-60%). Thus, the main changes occurred at a different rate in CD4+ (about 20%). In these exceptional individuals the percentage of CD45RA+ cells among CD8+ T lymphocytes was even higher (about 50%), and only slightly lower than that of young donors (about 55-60%). Thus, the main changes occurred at a different rate in CD4+ and in CD8+ T cells, at an age of between 0 and 30 years, when the thymus is still functionally active. Interestingly, no difference in the usage of CD45 isoforms was observed within T cells bearing four different V beta-T cell receptor (TCR). The significance of this age-related unbalance is unknown. However, the presence of a great number of CD45RA+ T lymphocytes within the CD4+ and the CD8+ T cell subsets even in the peripheral blood of centenarians poses the problem of their origin (thymus? extrathymic sites?), of their functional role and of their lifespan. Moreover, the data on centenarians suggest that they may represent a very selected population where a slowing of immunosenescence occurs.

Adolescent↗
PubMed1996

Pathological esophageal acidification and pneumatic dilitation in achalasic patients. Too much or not enough?

Endoscopy, esophageal manometry and pH monitoring, gastric emptying test, and heartburn quantification on a visual analog scale were performed in 22 achalasic patients in order to clarify which events are associated with pathological esophageal acidification after successful LES dilatation. Five patients presented pathological acidification. Dilatation reduced LES tone from 38.3 +/- 4.2 to 14.6 +/- 1.1 mm Hg (mean +/- SEM); there was, however, no difference between nonrefluxers and refluxers (14.8 +/- 1.2 vs 13.8 +/- 2.5 mm Hg). The emptying time in achalasic patients was delayed compared to controls (315.9 +/- 20.9 min vs 209 +/- 10.4) due to prolonged lag-phase and reduced slope of the antral section-time curve, but, again, there was no difference between refluxers and nonrefluxers. The acid clearance was delayed in refluxers compared to nonrefluxers (15.9 +/- 4.5 vs 2.5 +/- 1.8 min, P<0.05). Two refluxers presented grade 1 esophagitis; one of them developed an esophageal ulcer. The heartburn score was the same in refluxers and nonrefluxers. Pathological acidification after pneumatic dilatation is associated with persistent problems in esophageal emptying rather than with excessive sphincter divulsion.

Adult↗
PubMed1996

Omeprazole causes delay in gastric emptying of digestible meals.

We have studied gastric emptying of a solid, realistic meal (800 cal, 15% protein, 45% fat, 40% carbohydrate) in 21 healthy subjects twice, with and without a four-day pretreatment with 40 mg omeprazole. The last dose of the drug was taken 24 hr before the test, to avoid hypothetical nonsecretory side effects of the drug . Gastric emptying was measured by ultrasound of antral diameters. The results show that basal and maximal postprandial antral cross-sectional areas were the same during the two tests. A greater residual distention of the antrum was present throughout the study after the omeprazole treatment, the difference being significant at time 120 and 240. Omeprazole induced a highly significant delay in gastric emptying [control 199.6 (12.6) vs omeprazole 230.9 (12.7) min, mean (1 SEM); P<0.003]. The delay was not due to a prolonged lag phase, but rather to an effect on the slope of the emptying curve. This study shows that in normal subjects omeprazole delays gastric emptying of a digestible solid meal.

Adult↗
PubMed1996

Community-acquired pneumonia in a cohort of former injection drug users with and without human immunodeficiency virus infection: incidence, etiologies, and clinical aspects.

Although the association among bacterial pneumonia, human immunodeficiency virus (HIV) infection, and injection-drug use seems to have been well established, accurate estimates of the risk of community-acquired pneumonia among HIV-positive and HIV-negative injection-drug users (IDUs) are still needed. To estimate the incidence of pneumonia in a community of former IDUs, we followed 4,236 persons between 1991 and 1994; 1,114 (26.3%) were HIV-positive and 3,122 (73.7%) were HIV-negative. All patients were evaluated for pneumonia by standard criteria, a serum sample was obtained from each participant at least once a year, and laboratory values were monitored. Overall, 149 episodes of pneumonia occurred among HIV-positive patients and 61 among HIV-negative patients; incidence rates were 90.5 and 14.2 (per 1,000 person-years), respectively. The most common etiologic agents were Streptococcus pneumoniae, Chlamydia pneumoniae, and Haemophilus influenzae. Among the HIV-positive former IDUs, there was a 1.37-fold increase in the relative risk of pneumonia for every decrease of 100/mm3 in the CD4 cell count (95% confidence interval, 1.16-1.61). The incidence of community-acquired pneumonia was markedly higher among HIV-positive participants than among HIV-negative ones, a finding similar to that concerning the general population.

AIDS-Related Opportunistic Infections↗
PubMed1996

Gastric emptying and dyspeptic symptoms in patients with gastroesophageal reflux.

OBJECTIVES: To clarify 1) whether gastric emptying of a mixed meal is delayed in patients with gastroesophageal reflux and 2) the relationship between dyspeptic symptoms and delayed gastric emptying in refluxers. METHODS: Gastric emptying of a solid meal was studied by ultrasound in 25 patients with pathological esophageal acid exposure. Gastric emptying was then assessed in relation to upper digestive endoscopy, esophageal manometry, 24-h pH monitoring and quantification of symptoms of reflux- and dysmotility-like dyspepsia. RESULTS: Fifteen of 25 refluxers had esophagitis, and 15 were "dyspeptic". Refluxers exhibited a significant delay in gastric emptying compared with controls [307.6 (21.0) vs. 209 (10.4) min, p < 0.001). Patients with delayed emptying had low LES pressure [11.9 (2.1) vs. 18.6 (2.1) mm Hg, p < 0.05]. There was no correlation between delayed emptying and either pH monitoring or presence of esophagitis. There were no differences in any of the pH monitoring parameters between refluxers with and without coexisting dysmotility-like symptoms. CONCLUSIONS: Gastric emptying of a solid meal is markedly delayed in patients with gastroesophageal reflux. However, no direct causal link was found between delayed emptying and reflux. Our data suggest the presence of a motility disorder in gastroesophageal reflux which is not confined to the esophagogastric junction.

Adult↗
PubMed1995

Suicide attempted by burning: a 10-year study of self-immolation deaths.

In a 10-year retrospective survey of 699 admissions to the Burns Centre of Verona, 31 patients (4.4 per cent) had self-inflicted burns. No sex difference was found, the mean age was 38 years, with 58 per cent of the patients in the 20-39-year age group. The mean burned surface area (BSA) was 41 per cent, and 12 patients (38.7 per cent) died: seven within the first 24 h. The other five patients died within 40 days (mean survival: 18 days). A large number of patients had a history of previous psychiatric treatment, six patients had previously attempted suicide. Four patients were drug addicts, three of whom were affected by AIDS and one had been HIV-positive for a long time. The patients had continuous psychiatric treatment during the long hospital stay. After discharge the patients were assigned to territorial staff for psychiatric treatment. Our experience shows that these patients have a higher mortality rate and they need constant psychiatric support, which can be useful in preventing further suicide attempts.

Adult↗
PubMed1995

Gastric emptying of a solid meal is accelerated by the removal of dietary fibre naturally present in food.

Exogenous fibre added to liquid meals delays gastric emptying. Its effect on solid meals is uncertain, and nothing is known of the effect on gastric emptying of fibre naturally present in food. This study therefore looked at gastric emptying of two different solid meals in eight healthy subjects and their blood glucose responses. The meals were exactly equivalent except for the total dietary fibre content (high fibre 20 g, low fibre 4 g of dietary fibre per 1000 kcal) and supplied 870 kcal (700 kcal women), 47% of which was from carbohydrates, 36% from fats, and 17% from proteins. Ultrasonography was used to measure antral diameters before the meal (basal), immediately after it (time 0), and at 30, 60, 120, 180, 240, and 300 minutes. In addition, subjects filled in a questionnaire on their feelings of hunger, epigastric fullness, and satiety before the meal and at hourly intervals after it. Basal and maximal postprandial antral sections were similar for the two meals (basal section: 283.9 (29.5) v 340.9 (44.7) mm2 for the low and the high fibre meal, NS; maximal postprandial section: 1726 (101.9) v 1593 (120.4) mm2, NS). Total gastric emptying time was significantly reduced by fibre removal (186.0 (15.6) v 231.7 (17.3) minutes after the low and the high fibre meal, p < 0.05). Blood glucose was higher after the low fibre meal, and the area under the glycaemic curve significantly greater (226 (23.1) v 160 (20.0) mmol/min/dl-1, p < 0.05). No difference was found in satiety or fullness feelings, but hunger returned more rapidly after the low fibre meal. In conclusion, fibre naturally present in food delays gastric emptying of a solid meal, reduces the glycaemic response, and delays the return of hunger.

Adult↗
PubMed1995

Effect of neutralized and native vinegar on blood glucose and acetate responses to a mixed meal in healthy subjects.

OBJECTIVE: To investigate the influence of sodium acetate and acetic acid from vinegar on blood glucose and acetate response to a mixed meal in healthy subjects. DESIGN: Five healthy subjects consumed in random order six test meals consisting of 100 g of sliced lettuce dressed with olive oil (Blank), olive oil plus 1 g acetic acid in the form of vinegar (AcOH), or olive oil plus sodium acetate in the form of vinegar neutralized to pH 6.0 with sodium bicarbonate (AcNa). On three occasions test meals were followed by a challenge consisting of 50 g carbohydrate portions of white bread (Bread). Glucose and acetate concentrations were measured in arterialized capillary blood before and until 95 min after the meals. Ultrasonography was performed in four other subjects to measure gastric emptying times after AcOH + Bread and AcNa + Bread. RESULTS: Blood acetate response over 95 min was markedly reduced after AcOH and AcOH+Bread meals compared to AcNa and AcNa + Bread. Similarly, the glucose response was depressed by 31.4% (P = 0.0228) after AcOH+Bread with respect to AcNa + Bread and Blank + Bread. No difference was observed between gastric emptying times after AcOH + Bread and AcNa + Bread. CONCLUSIONS: The results suggest that oral acetic acid and acetate might have a different effect on acetataemia and that a limited dose of vinegar, in the form of salad dressing, is sufficient to influence significantly the glycaemic response to a mixed meal in normal subjects by a mechanism related to acidity but not to gastric emptying.

Acetates↗
PubMed1994

Gastric emptying of solid meals in achalasic patients after successful pneumatic dilatation of the cardia.

Gastric emptying of a solid meal was measured by ultrasound scanning in 16 achalasic patients following successful pneumatic dilatation of the lower esophageal sphincter. The data were compared with those of a control group of 15 healthy subjects. Fasting and maximal postcibal antral sections were very similar in the two groups. On the contrary, the time interval before maximal antral dilatation, and the time necessary for the emptying of half or of the whole meal were significantly longer in the achalasic patients than in the controls. Half of the achalasic patients had longer emptying times than the upper normal limit. The percentage of the meal retained in the antrum at each hourly interval was significantly higher in the achalasic group. The finding of a high prevalence of gastric emptying disturbances suggests that the functional derangement in achalasia is not limited to the esophagus.

Catheterization↗
PubMed1994

Gastric emptying of solids is markedly delayed when meals are fried.

We studied the effect of heat-treated fats on gastric emptying. Eight healthy asymptomatic volunteers (five males; age 28-41 years) ate on different days and in random order two meals identical in contents (pasta, tomato, beef, olive oil, carrots, orange, water; 870 kcal males, 700 kcal females; 47% of calories from carbohydrate, 36% from fat, 17% from protein), but cooked differently (fats fried or not). Ultrasound measurement of antral diameters was used to calculate basal antral section, its maximal dilation after the meal, the time necessary for total emptying, and the percent retention at hourly intervals. No difference was found in basal and maximal antral diameters after the two meals. On the contrary, total gastric emptying was significantly delayed after the fried meal [317.1 (24.12) vs 226.7 (18.4) min, mean (1 SEM); P < 0.002]. A significantly greater percentage of maximal antral distension was still present between 120 and 240 min after the fried meal. The glycemic response and hunger feeling were the same after the two meals, whereas there was a longer persistence of satiety and epigastric fullness after the fried meal. In conclusion, gastric emptying can be influenced not only by the meal content, but also by the way it is cooked.

Adult↗
PubMed1993

[In vitro study of a new pancreatic enzyme with high lipase content in enteric coated microtablets].

In vitro behaviour of the enteric-coating of a new pancreatic enzyme containing preparation in enteric-coated microtablets was evaluated, by incubating at 37 degrees C, under gentle agitation, the preparation under study in buffered gastric (pH 2, 3, 4, 5, 6) and in buffered duodenal juice (pH 3, 4, 5, 6, 7, 8) for 30, 60, 90, 120 minutes. Lipase and chymotripsin activities were measured at each time and pH in the solution and in the undissolved microtablets. The drug under study showed a good enteric-coating, preserving about 100% of the enzyme content, when incubated in buffered gastric juice, up to pH 6, and releasing in the solution, during incubation in buffered duodenal juice, 75% of its enzyme content at pH 7 and 8. Therefore, the pancreatic enzymes contained in this new enteric-coated microtablet preparation are well protected against inactivation from acid and are bioavailable for digestion of alimentary substrates at optimal or near optimal pH in duodenal juice.

Biological Availability↗