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Biomedical subjects

R Grasso

Publications and source records attributed to R Grasso.

At least 55 records · Page 3Linked to original sources
PubMed1995

Vascular resistance and arterial pressure low-frequency oscillations in the anesthetized dog.

The spontaneous variability of heart rate and arterial blood pressure was investigated in chloralose-anesthetized dogs with the left iliac vascular bed mechanically uncoupled from the central circulation. Electrocardiogram, mean arterial pressure (ABP), iliac perfusion and venous pressures, and flow (FLOW) were recorded for 5 min in steady state. Autoregressive spectral and cross-spectral analyses and digital filtering were performed. The variation coefficient (VC%), calculated from the overall variance of each signal, was 5-7%, with the exception of perfusion pressure (VC% = 1%). The frequency-related percentage of total variance was distributed among three frequency bands: two were < 0.20 Hz [lower (F1) and higher (F2; low-frequency range = F1 + F2)], and one was > 0.20 Hz (respiratory, F3). F3 was not always present in RR, which, however, oscillated also in F1 and F2, although with limited amplitude; ABP showed large respiratory and low-frequency oscillations; the FLOW oscillations were in the low-frequency range. Cross-spectral analysis showed high squared coherence in the relevant frequency bands between variables in the three couples: RR-ABP, RR-FLOW, and ABP-FLOW. Changes in RR preceded changes in ABP and in FLOW by > or = 3 s, whereas FLOW was approximately in phase opposition to ABP. It was concluded that, in the chloralose-anesthetized dog, 1) arterial pressure and heart rate oscillate with frequencies corresponding to those described in conscious humans, 2) low-frequency arterial pressure oscillations are due to changes in peripheral vascular resistance, and 3) peripheral vascular resistance does not display respiratory oscillations. Furthermore it was suggested that oscillations of vasomotor tone are generated by a rhythm of central origin and that F1 and F2 oscillations may recognize a common mechanism.

Analysis of Variance↗
PubMed1994

Screening for hepatocellular carcinoma in patients with Child's A cirrhosis: an 8-year prospective study by ultrasound and alphafetoprotein.

One hundred and forty-seven patients with Child's A cirrhosis and no evidence of hepatocellular carcinoma were followed up in an 8-year prospective surveillance program with testing by ultrasound and alphafetoprotein every 6 months. Eighteen of 147 patients were HBsAg positive. Anti-hepatitis C virus antibodies were found in 103 out of 133 cases tested. Sixteen patients had a history of heavy drinking. Thirty hepatocellular carcinomas were detected during follow up. At the time of diagnosis, ultrasound detected focal lesions in all the patients whereas alphafetoprotein was below diagnostic levels. The hepatocellular carcinoma was single in 26 patients and multiple in four. The overall 8-year cumulative tumor-free rate was 69% (95% confidence interval = 58-73). The yearly hepatocellular carcinoma incidence from 1985 to 1992 was respectively 2%, 1.5%, 2%, 3%, 5%, 4.8%, 7% and 10%. The initial value of AFP > 50 ng/ml and < 400 ng/ml was significantly related to the development of hepatocellular carcinoma. This series shows that the cumulative incidence of hepatocellular carcinoma in cirrhosis in Italy is higher than previously reported, but lower than that observed in Asiatic areas. A 6-month interval for ultrasound is reasonable to detect treatable tumors. Alphafetoprotein has no value for early diagnosis, although its intermediate values (> 50 and < 400 ng/ml) may indicate the presence of undetectable cancer which will appear during the follow up, and suggests that ultrasound should be employed more frequently in patients with these values.

Aged↗
PubMed1993

Biliary sludge and gallstones in pregnancy: incidence, risk factors, and natural history.

OBJECTIVE: To evaluate the incidence and symptoms of and risk factors for biliary sludge and gallstones during pregnancy and to assess the natural history of these conditions in the first year after delivery. DESIGN: Cohort study. PATIENTS: A total of 272 pregnant women recruited in the first trimester. MEASUREMENTS: Biliary sludge and gallstones were diagnosed using ultrasonography, both during pregnancy and after delivery. Predictors of the presence or disappearance of sludge and stones were examined. MAIN RESULTS: Overall, from the first trimester of pregnancy until the immediate postpartum period, 67 women were newly diagnosed with biliary sludge, and 6 women were newly diagnosed with gallstones. The respective incidence rates were 31% (95% Cl, 25% to 37%) and 2% (95% Cl, 0.2% to 4%). During pregnancy, 28% of women experienced biliary pain, which was associated only with presence of stones. After delivery, 92 women had sludge and 23 had stones. Sludge disappeared in 61% of these women (Cl, 50% to 73%) after a mean follow-up of 5 months, and stones disappeared in 28% of women (Cl, 10% to 46%) after 9.7 months of follow-up. CONCLUSIONS: Biliary sludge occurred frequently during pregnancy but was generally asymptomatic and often disappeared spontaneously after delivery. Gallstones were much less frequent and were more likely to be associated with biliary pain.

Adult↗
PubMed1993

Peripheral blood flows during colorectal distension in anaesthetised dogs.

Distension of the descending colon elicits reflex cardiovascular responses, including increases in heart rate and arterial blood pressure. To study the relative contribution of vasoconstriction in individual vascular beds to this reflex response, experiments were performed on seven dogs anaesthetised with chloralose and instrumented with electromagnetic flowmeters around the superior mesenteric, the left renal and the left external iliac arteries. The colorectal portion of the intestine was distended at constant pressure (36.6 mm Hg, 4.9 kPa mean; range 25-50 mm Hg, 3.3-6.7 kPa) with warm Ringer solution for periods of 2 min. After a set of control distensions, the experiments were performed whilst the reflex rise in arterial pressure was prevented by removal of blood from the arterial tree. In control distensions arterial pressure increased by 11.3 +/- 1.5 mm Hg, 1.51 +/- 0.12 kPa (mean +/- SEM). In distensions at constant arterial pressure, peripheral blood flows were altered to different extents in the three territories studied: vascular resistance increased by 30.8 +/- 5.6% (P < 0.01) in the mesenteric, by 4.1 +/- 1.5% (P < 0.03) in the renal, and by 15.2 +/- 6.8% (NS) in the external iliac bed. We conclude that colorectal distension may reflect activation of a function-specific pathway of the sympathetic nervous system, which leads to much greater vasoconstriction in the splanchnic circulation than in renal or musculocutaneous circulations.

Analysis of Variance↗
PubMed1993

Clinical presentation and ultrasonography in the diagnosis of pancreatic cancer.

One thousand twenty patients consecutively admitted because of a clinical suspicion of pancreatic cancer were investigated to evaluate the accuracy of simple clinical, laboratory, and ultrasonographic data in the diagnosis of pancreatic cancer. Age, weight loss, recent-onset diabetes mellitus, palpable abdominal mass or gallbladder, elevated serum bilirubin or alkaline phosphatase levels, and ultrasonography were significant criteria in discriminating 80 pancreatic cancers from 940 controls. The most sensitive criteria were ultrasonography (83%), weight loss (66%), and bilirubin level of > 3 mg/dl (61%); the most specific were ultrasonography (99%), recent-onset diabetes (97%), and a distended palpable gallbladder (94%). Only ultrasonography demonstrated an elevated positive predictive value (86%), while weight loss, elevated bilirubin and alkaline phosphatase, besides ultrasonography had an elevated negative predictive value (95%). These results show that advanced pancreatic cancer may be excluded with simple clinical and laboratory data; ultrasonography can confirm the diagnosis with a high degree of accuracy. We suggest that the results of any new diagnostic tests for pancreatic cancer be compared with these clinical findings.

Adult↗
PubMed1992

Spontaneous beat-to-beat variability of the ventricular repolarization duration.

The spontaneous beat-to-beat variability of the ventricular repolarization duration was investigated in 21 healthy subjects (age 25-71 years; mean, 40 years) during the basal state in a recumbent position. For each subject, approximately 1,000 consecutive cycles were analyzed with an automated technique. The time series of the RR, QT, and RT intervals generate histograms that approximate normal distributions and have mean standard deviations of 57.0 ms, 5.4 ms, and 4.3 ms, respectively. Spectral analysis was used to detect rhythmical oscillations in these time series. The power spectra densities of both heart rate and ventricular repolarization during show peaks in the same frequency bands: low frequency (0.05-0.12 Hz) and high frequency (0.2-0.4 Hz). The power distribution between these two bands observed in the ventricular repolarization duration spectra was found to be the reverse of that in heart rate spectra (p less than 0.005).

Adult↗
PubMed1991

Abdominal ultrasonography in the diagnosis of extrinsic endoscopic compressions of stomach and duodenum.

Extrinsic compressions of stomach or duodenum (ECSD) are occasionally found during endoscopic examination. Ultrasonography is usually performed in order to explain the significance of this feature. We have prospectively assessed the prevalence of ECSD and the diagnostic role of US in this context. ECSD were found in 37 out of 6604 gastroduodenoscopies. An abdominal US was performed after endoscopy in all these patients. The extrinsic compressions were in the gastric anterior wall in 7 patients in the gastric posterior wall in 10 patients, and in the lesser curvature in 9 patients and in the duodenum in 11 patients. In 20 patients the compression was due to neoplastic lesions, in another 15 non neoplastic conditions were found (hepatomegaly, splenomegaly, gallbladder hydrops, pancreatic pseudocyst, vascular malformations). Ultrasonography was demonstrated to have an elevated sensitivity (87.5%) and an elevated specificity (100%) when technically adequate. We conclude that extrinsic compressions of stomach and duodenum detected at endoscopy are frequently associated to neoplastic lesions. Abdominal ultrasonography is an accurate tool, when technically adequate, as an initial screening test for such lesions. Endosonography, CT scan or other invasive tests must be performed in doubtful cases.

Aged↗
PubMed1986

Effects of aztreonam and netilmicin upon alveolar macrophage function.

Both aztreonam and netilmicin showed no toxic effect on alveolar macrophage function when administered at varying concentrations. Killing ability was unchanged as well. The increase of enzyme delivery, assessed at varying concentrations, was very limited and of no relevance in the pathogenesis of possible tissue damage. It can be explained on the basis of a change in the permeability of membranes or to output during phagocytosis. In cultures containing either antibiotic under similar conditions we did not note any substantial differences. The concentrations tested can be used safely in the therapy of infections due to most gram-negative bacteria.

Acid Phosphatase↗