Biomedical subjects

R Orlando

Publications and source records attributed to R Orlando.

At least 91 records · Page 5Linked to original sources

PubMed1995

Detection of hepatitis C virus-RNA by polymerase chain reaction in dental surgeries.

The mean prevalence of anti-hepatitis C virus (HCV) in Italy is 0.87%. It reaches 2% in Campania, Southern Italy. Approximately 50% of community acquired non-A, non-B (NANB) hepatitis cannot be associated with known parenteral exposure. A recent Italian study has shown that the only demonstrable risk factor in 9% of acute C/NANB hepatitis is dental treatment. There are no data on direct contamination by HCV of dental surgeries. Possible environmental contamination by HCV-RNA was investigated in dental surgeries after treatment of anti-HCV and HCV-RNA positive patients. Thirty-five anti-HCV and HCV-RNA positive patients with chronic hepatitis underwent dental treatment and were enrolled in this study. Eight had chronic persistent hepatitis (CPH), 23 chronic active hepatitis (CAH), and 4 cirrhosis. A total of 328 samples collected from instruments and surfaces were tested after dental treatment of 35 anti-HCV positive patients. The presence of HCV-RNA was determined by polymerase chain reaction (PCR) to evaluate contamination of instruments and surfaces in dental surgeries. Twenty (6.1%) out of 328 collected samples were positive for HCV-RNA. The positive samples were from work benches (two), air turbine handpieces (one), holders (four), suction units (one), forceps (four), dental mirrors (two), and burs (six). Our data indicate that there is extensive contamination by HCV of dental surgeries after treatment of anti-HCV patients and that if sterilisation and disinfection are inadequate there is the possible risk of transmission to susceptible individuals.

Base Sequence↗

PubMed1995

Anions and the anomalous gel filtration behavior of notexin and scutoxin.

Based on their mol. wts, notexin and scutoxin elute later than expected from gel filtration columns in multiple peaks [Francis et al. (1991) Toxicon 29, 85-96]. Notexins present in these peaks have identical amino acid sequences and unmodified amino acid side-chains. Scutoxin is an isoform of notexin which contains arginine at position 16 and glutamate at position 82. Like notexin, it also elutes in different fractions on a gel filtration column, yet the fractions show identical amino acid sequence. This perplexing chromatographic behavior appears to be caused by the association of these proteins with different anions, since dissolving notexin in buffers containing different anions produces up to a 30% change in elution volume. Certain anions promote an apparent reduction in the interaction of notexin with gel filtration matrix, hence earlier elution. These anions include citrate, 3-phosphoglycerate and 2-phosphoglycerate, which also inhibit the PLA2 activity of notexin. However, even under conditions which minimize protein-matrix interaction the toxins elute later than expected based on their mol. wt.

Amino Acid Sequence↗

PubMed1995

The pharmacokinetics of teniloxazine in healthy subjects and patients with hepatic cirrhosis.

The single-dose and steady-state pharmacokinetics of teniloxazine, an investigational drug with antidepressant and anti-anoxic properties, were compared in 12 healthy volunteers and 12 cirrhotic patients, following oral administration of 80 mg teniloxazine maleate every 12 h for 7 days. In healthy volunteers, an increase in oral clearance, CLo (from a mean (s.d.) value of 14.6 (3.9) to 18.0 (6.6) ml min-1 kg-1; mean % ratio between the two values (95% CI), 123 (94-151)) and a significant shortening of t 1/2 (from 6.2 (2.7) to 4.8 (1.4) h; mean % ratio (95% CI), 78 (58-98)) were observed upon repeated administration, suggesting autoinduction of teniloxazine metabolism. In cirrhotic patients, the pharmacokinetic parameters of teniloxazine remained essentially invariant with time. Compared with normal subjects, CLo was about halved in cirrhotic patients, whereas t 1/2 was more than doubled. As a consequence of these modifications, the multiple-dose regimen resulted in a two-fold mean drug accumulation in cirrhotic patients, compared with virtually no accumulation in healthy volunteers. Although no adverse events were noted in either study group, it is suggested that maintenance doses for patients with liver dysfunction should initially be at the lower end of the therapeutic range.

Administration, Oral↗

PubMed1995

The lipoprotein composition of plasma and ascitic fluid in liver cirrhosis.

Lipoprotein particles were examined in plasma and ascitic fluid from nine patients (5 males and 4 females) with liver cirrhosis and in plasma from nine control subjects. LDL and HDL fractions were isolated by ultracentrifugation under rate flotation conditions in a zonal rotor. LDL size was analysed by non-denaturing polyacrylamide gradient gel electrophoresis. Plasma lipids in cirrhotic patients were markedly reduced compared to controls. Free cholesterol represented 45.3% of the total cholesterol in plasma and 70.4% of the total cholesterol in the ascitic fluid. The total cholesterol-triglyceride ratio was three times higher in the plasma than in the ascitic fluid of cirrhotic patients. The LDL particles had the same flotation properties in plasma from cirrhotic patients as in that from controls. In cirrhotic patients the IDL concentration was higher than that in controls. In ascitic fluid the LDL particles had a higher flotation rate than in the plasma. The LDL diameter as measured by gradient gel electrophoresis was similar in both plasma and ascitic fluid of the cirrhotic patients as well as in the plasma of controls. In plasma and ascitic fluid of cirrhotic patients only a single HDL subclass (HDL1) could be identified. HDL1 particles had a higher flotation rate than normal HDL particles. The plasma levels of all the apoproteins were reduced in cirrhotic subjects compared to controls, but to a variable degree; while apo CII level in cirrhosis represented only 9% of the control level, the apo E level represented 77% of the control level.(ABSTRACT TRUNCATED AT 250 WORDS)

Ascites↗

PubMed1995

Antepartum diagnosis of pancreatic carcinoma: a case report.

A pregnant patient found to have primary carcinoma of the pancreas is discussed. The extreme rarity of this condition is emphasized. There are only a handful of cases reported in the world literature, and the diagnoses in these reports were made almost exclusively post partum. We could find only two reported cases in which the diagnosis was made ante partum, those by Gamberdella in 1984 and by Duff and Greene in 1985. The case we present demonstrates the difficult management decisions that arise when the diagnosis of pancreatic carcinoma is made in the midst of gestation.

Adenocarcinoma↗

PubMed1994

Hydrophilic-interaction chromatography of complex carbohydrates.

Complex carbohydrates can frequently be separated using hydrophilic-interaction chromatography (HILIC). The mechanism was investigated using small oligosaccharides and a new column, PolyGLYCOPLEX. Some carbohydrates exhibited anomer separation, which made it possible to determine the orientation of the reducing end relative to the stationary phase. Amide sugars were consistently good contact regions. Relative to amide sugars, sialic acids and neutral hexoses were better contact regions at lower levels of organic solvents than at higher levels. HILIC readily resolved carbohydrates differing in residue composition and position of linkage. Complex carbohydrate mixtures could be resolved using volatile mobile phases. This was evaluated with native glycans and with glycans derivatized with 2-aminopyridine or a nitrobenzene derivative. Both asialo- and sialylated glycans could be resolved using the same set of conditions. With derivatized carbohydrates, detection was possible at the picomole level by UV detection or on-line electrospray mass spectrometry. Selectivity compared favorably with that of other modes of HPLC. HILIC is promising for a variety of analytical and preparative applications.

Animals↗

PubMed1994

Blood in saliva of patients with acquired immunodeficiency syndrome: possible implication in sexual transmission of the disease.

The presence and concentration of haemoglobin in saliva of anti-human immunodeficiency virus (HIV) positive subjects, anti-HIV-negative subjects at high risk of infection, and healthy controls were studied. One hundred eighty-eight subjects were anti-HIV-positive intravenous drug abusers (IVDA), 22 were anti-HIV-positive homosexual men, 23 were anti-HIV-positive heterosexual contacts, 132 were anti-HIV-negative IVDA, 35 were anti-HIV-negative homosexual men, and 154 were healthy controls. Two milliliters of saliva was collected in the morning before brushing teeth, and the presence and the concentration of haemoglobin were determined. Based on hemoglobin, the data show that the anti-HIV-positive IVDA have the highest tendency to bleeding. The difference between this group with respect to anti-HIV-negative IVDA (P < 0.05) and compared with healthy controls (P < 0.01) is statistically significant. This is also true of anti-HIV-positive heterosexual contacts with respect to healthy controls (P < 0.01). Our data show that all at-risk groups, both anti-HIV positive and anti-HIV negative, have higher haemoglobin concentration than the control group; this difference reaches statistical significance only between anti-HIV-positive IVDA and controls (P < 0.01). The concentration of haemoglobin is significantly higher in subjects with CD4+ lymphocytes < 200/mm3 compared to subjects with CD4+ lymphocytes > 200/mm3 (P < 0.01), in subjects with AIDS-related complex (ARC)/AIDS compared to asymptomatic/PGL subjects (P < 0.01), and in subjects with stomatitis compared to subjects without stomatitis (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1994

Physiologic effects of pneumoperitoneum.

Laparoscopy requires the establishment of pneumoperitoneum in order to provide adequate surgical exposure and maintain operative freedom. Insufflation of carbon dioxide into the peritoneal cavity, however, can affect several homeostatic systems, leading to alterations in acid-base balance, blood gases, and cardiovascular and pulmonary physiology. Although these changes may be well tolerated by healthy individuals, they may increase physiologic stress in patients with pre-existing conditions, placing them at increased risk for perioperative complications. An understanding of the physiologic changes caused by carboperitoneum is therefore essential for identification of high-risk patients and formulation of appropriate treatment plans, which may include preoperative cardiorespiratory optimization and perioperative monitoring. Under optimal conditions, debilitated patients should be able to tolerate pneumoperitoneum safely and, thereafter, reap the benefits associated with minimally invasive surgery.

Carbon Dioxide↗

PubMed1994

Fasting and postprandial phenylalanine and leucine kinetics in liver cirrhosis.

To investigate body protein turnover and the pathogenesis of increased concentration of plasma phenylalanine in liver cirrhosis, we have studied phenylalanine and leucine kinetics in cirrhotic (diabetic and nondiabetic) patients, and in normal subjects, both in the postabsorptive state and during a mixed meal, using combined intravenous and oral isotope infusions. Postabsorptive phenylalanine concentration and whole body rate of appearance (Ra) were approximately 40% greater (P < 0.05) in patients than in controls. Leucine concentrations were comparable, but intracellular leucine Ra was also increased (P < 0.05), suggesting increased whole body protein breakdown. Postprandial phenylalanine Ra was also greater (P < 0.05) in the patients. This difference was due to a diminished fractional splanchnic uptake of the dietary phenylalanine (approximately 40% lower in the cirrhotics vs. controls, P < or = 0.05). Postprandial leucine Ra was also increased in the patients, but splanchnic uptake of dietary leucine was normal. Thus both increased body protein breakdown and decreased splanchnic extraction of dietary phenylalanine can account for the increased phenylalanine concentrations in liver cirrhosis.

Adult↗

PubMed1994

Immunoassays for serum and urine myoglobin: myoglobin clearance assessed as a risk factor for acute renal failure.

We compared four immunoassays for serum and urine myoglobin. Within-run CVs were 5-13%, with biases seen between assays. Myoglobin was stable for 1 month in serum and 12 days in urine when the pH was adjusted to between 8.0 and 9.5. Hemoglobin caused no interference. We assayed 91 pairs of serum and timed urine specimens from 41 patients admitted for acute trauma or rhabdomyolysis. Most were treated with mannitol and alkalinization. Upon initial presentations, 21 patients with either low serum myoglobin concentrations (< 400 micrograms/L) or high myoglobin clearances (> or = 4 mL/min) had normal creatinine clearances and no clinical evidence of renal disease. The remaining 20 had low myoglobin clearances. Seven were in rhabdomyolysis-induced acute renal failure, or subsequently developed this complication. We suggest that low myoglobin clearance may indicate a high risk for developing renal failure or may be an early marker for kidney dysfunction. Low myoglobin clearance may prove useful in indicating failure of prophylactic treatment to clear myoglobin.

Acute Kidney Injury↗

PubMed1993

Separation of the sticky peptides from membrane proteins by high-performance liquid chromatography in a normal-phase system.

The amphiphilic peptides obtained upon cleavage of membrane proteins, including numerous receptors, are recalcitrant to most separation techniques as a consequence of their limited solubility and tendency to aggregate and adsorb to surfaces. This paper describes HPLC systems that can separate these "sticky" peptides on silica and aminopropyl-modified silica columns with a mobile phase consisting of a mixture of chloroform/methanol/isopropylamine. The protocols developed have been applied to synthetic M1 and M2 peptides, which constitute part of the transmembrane domain of glutamate-gated ion-channel proteins. Four of these M1 and M2 peptides were separated from minor synthetic impurities, and a 23-mer was baseline separated from a 28-mer. The HPLC procedures have also led to purification of the 10 peptides resulting from cyanogen bromide cleavage of bacteriorhodopsin, peptides which have so far eluded HPLC separation despite numerous attempts. These HPLC protocols have been used to purify peptides ranging from 4 to 50 amino acids in high yield while the columns continued to resolve sharp peaks after more than 100 separation runs over a 6-month period. These new HPLC systems offer an efficient method for the isolation and analysis of this important albeit troublesome class of peptides.

Amino Acid Sequence↗

PubMed1993

Laparoscopic cholecystectomy. A statewide experience. The Connecticut Laparoscopic Cholecystectomy Registry.

The explosion in laparoscopic cholecystectomy has posed many questions about its safety compared with the "gold standard" of open cholecystectomy. A statewide database was established in Connecticut to study these issues. Thirty-three (97%) of 34 hospitals in Connecticut participated in the study, which began at the inception of the laparoscopic procedure. Four thousand six hundred forty laparoscopic cholecystectomies were performed between May 1, 1990, and September 30, 1991. The overall conversion rate to open cholecystectomy was 6.9%. Conversions were more frequent with acute cholecystitis, in the elderly, and early in a surgeon's experience. The overall technical complication rate was 4.7%; common bile duct injuries occurred in 15 patients (0.3%). Complications decreased with increasing experience, to 0.98% after a surgeon's 75th procedure. Six patients (0.13%) died following laparoscopic cholecystectomy. The overall mortality rate associated with cholecystectomy fell during the study period. The frequency of cholecystectomy in Connecticut increased 29% with the advent of the laparoscopic procedure. The introduction of laparoscopic cholecystectomy has resulted in an increased frequency of surgery without an increase in surgical mortality. The incidence of common bile duct injuries was low. The decreasing incidence of technical complications demonstrates the learning curve for the procedure.

Adult↗

PubMed1993

Laparoscopic appendectomy. A safety and cost analysis.

To assess the feasibility of laparoscopic appendectomy, we reviewed hospital records and charge data for all patients older than age 15 years who underwent appendectomy between November 1990 and July 1992. Fifty-eight patients underwent laparoscopic appendectomy and 206 patients underwent conventional appendectomy. Intraoperative (1.9%) and postoperative (5.8%) complication rates were low. The rate of conversion to conventional appendectomy was 7.7%. Hospital stay and charge analysis was performed on a cohort of 52 patients undergoing laparoscopic appendectomy and 180 patients undergoing conventional appendectomy. Total costs were similar. The most notable difference between the two groups was the operating room supply charge; this negated any cost savings achieved by the reduced length of stay following laparoscopic appendectomy. Laparoscopic appendectomy is a safe alternative to conventional appendectomy; it shortens hospital stay and allows patients to resume normal activity more quickly than conventional appendectomy.

Adolescent↗

PubMed1993

Dose-dependent absorption and elimination of gamma-hydroxybutyric acid in healthy volunteers.

Gamma-hydroxybutyric acid (GHB) is effective in treatment of the alcohol and opiate withdrawal syndromes. Its absorption and disposition kinetics have been studied in 8 healthy male volunteers following oral administration of single doses of 12.5, 25 and 50 mg kg-1. The AUC increased disproportionately with the dose and so the apparent oral clearance decreased significantly as the dose was increased, whereas the terminal half-life and mean residence time increased. The peak plasma concentrations normalised to the lowest dose fell significantly with increasing doses, whilst the corresponding peak times increased. These findings suggest that both the oral absorption and the elimination of GHB are capacity-limited processes. GHB did not bind to significant extent to plasma proteins over the therapeutic concentration range. The pharmacokinetic parameters in healthy volunteers were not significantly different from those previously observed in alcohol-dependent patients with compensated alcoholic liver disease.

Absorption↗

PubMed1993

Leucine and phenylalanine kinetics in compensated liver cirrhosis: effects of insulin.

BACKGROUND: The pathogenesis of the altered ratio of branched-chain amino acid to aromatic amino acid concentration in liver cirrhosis is poorly known. We explored the possible link between altered amino acid concentrations and kinetics in cirrhosis. METHODS: Post-absorptive leucine and phenylalanine rates of appearance (Ra) and their response to insulin were studied in patients with compensated, nondiabetic cirrhosis and in controls. RESULTS: In the cirrhotics, concentration of postabsorptive phenylalanine was greater and that of alpha-ketoisocaproate lower than in controls, whereas concentration of leucine was comparable. Leucine Ra was lower, phenylalanine Ra was greater, and the ratio of leucine Ra to phenylalanine Ra was markedly decreased (P < 0.001) in patients vs. controls (2.40 +/- 0.23 vs. 3.67 +/- 0.19, respectively). During an euglycemic-hyperinsulinemic clamp, glucose disposal was reduced and leucine Ra was suppressed more profoundly in cirrhotics than in controls, whereas suppression of phenylalanine Ra was comparable. CONCLUSIONS: In compensated liver cirrhosis, postabsorptive phenylalanine Ra is increased with respect to leucine Ra, suggesting the existence either of altered amino acid pools and/or transport or of abnormally sequenced proteins and/or peptides. Insulin resistance is restricted to glucose, but not to amino acid metabolism.

Adult↗

PubMed1993

Treatment of chronic hepatitis C with recombinant interferon alfa-2b.

In a study of 87 patients with chronic hepatitis C, 12 months' treatment with interferon alfa-2b at a dose of 6 million units (MU) three times per week seemed to be more effective than treatment with 3 MU three times a week for two months plus 1.5 MU three times a week for 10 months in increasing the percentage of long term responders. The percentage of patients in whom alanine amino-transferase activities returned to normal was highest in the 6 MU group, as was the percentage of responders who sustained this normal activity after treatment. Side effects were moderate and self-limited in most patients.

Adolescent↗

PubMed1993

[Demonstration of the interchangeability of 2 types of recombinant anti-hepatitis-B vaccine].

A vaccination cycle cannot always be completed with the same type of vaccine with which it was initiated because the same type of vaccine is not always available at the vaccination centers. For this reason we have verified the possibility of substituting one of two anti hepatitis B DNA-recombinant vaccines [Engerix B (SK&F); Recombivax HB (MSD)] both available in Italy in the vaccination protocol. A study was performed on 480 subjects using both types of DNA recombinant vaccine and on 160 using only one type of vaccine. Our data show that there is no difference in immunogenic potency of the two DNA recombinant vaccines available in Italy and that a cycle begun with one vaccine can be completed with the other with no effect on the percentage of seroconversion or the mean anti-HBs titre.

Adolescent↗

PubMed1993

Laparoscopy in high-risk cardiac patients.

Fifteen patients with severe cardiac disease (American Society of Anesthesiologists III or IV) underwent laparoscopy using radial artery and pulmonary artery catheters to determine intraoperative hemodynamic changes. Cardiac output (CO), mean arterial blood pressure (MAP), central venous pressure, heart rate, systemic vascular resistance (SVR) and mixed venous oxygen saturation (SVO2) were recorded before anesthetic induction, after induction, but before peritoneal insufflation, after insufflation and after release of pneumoperitoneum. Peritoneal insufflation led to significant elevations in MAP and SVR and reduction in CO. For seven patients, a decrease in SVO2 after peritoneal insufflation was predictive of significant worsening of hemodynamic parameters, suggesting inadequate cardiac reserve. In all patients, hemodynamic parameters returned toward baseline once pneumoperitoneum was released. There were no perioperative cardiac complications. While it is evident that laparoscopy presents serious hemodynamic stress, it can be performed safely in high-risk patients, using aggressive intraoperative monitoring.

Adult↗