Search PubMed⌕ Search

Biomedical subjects

R Orlando

Publications and source records attributed to R Orlando.

At least 109 records · Page 6Linked to original sources
PubMed1993

Techniques and complications of open packing of infected pancreatic necrosis.

Open packing of infected pancreatic necrosis has been used in a disease process that is known to have a high mortality rate. From 1982 to 1991, we managed 15 patients with infected pancreatic necrosis with this technique. The cause of the underlying pancreatitis was ethanol in seven patients, gallstones in four, drug induced in two, trauma in one patient and postoperative in one. At hospital admission, the mean number of Ranson's criteria was 4.5 (range of zero to 11). The diagnosis was made by computed tomographic scan in 13 patients, endoscopic retrograde cholangiopancreatography in one patient and clinically in one; eight patients demonstrated air in the pancreas or lesser sac. Operative débridement of the pancreas was performed by way of a midline incision in four patients and a transverse incision in 11 patients. All wounds were left open or closed partially over gauze packing; polyglycolic mesh was used as an adjunct to wound closure to prevent evisceration. Other procedures at initial operation included transverse colectomy (two patients), duodenal diverticulization (one patient), jejunostomy (six patients) and cholecystostomy (four patients). The mean number of subsequent dressing changes in the operating room was five (range of one to 13); subsequent dressing changes were performed in the intensive care unit. Three patients died (the survival rate was 80 percent). The mean period of time in the intensive care unit was 26 days (range of zero to 67 days). Early complications included pulmonary insufficiency in 14 patients, bleeding in four, intestinal fistulas in four and pancreatic fistula in one patient. The most common late complication was incisional hernia, which occurred in seven patients. We conclude that open packing of infected pancreatic necrosis is an effective treatment for this previously lethal condition. However, this treatment is labor intensive and requires a committed team of surgeons, interventional radiologists and critical care personnel. Attention to specific technical aspects of the procedure can minimize complications.

Acute Disease↗
PubMed1992

Covalent modification of Alzheimer's amyloid beta-peptide in formic acid solutions.

beta-peptide is a normal component of amyloid deposits in Alzheimer's disease. In aqueous solution, beta-peptide is extremely insoluble and rapidly aggregates forming oligomeric beta-sheet structures that eventually precipitate from solution. Presumably, this process is related to the production of amyloid deposits in Alzheimer's disease. Formic acid is commonly used to dissolve the beta-peptides and prevent aggregation in biological and biophysical studies. However, a side-reaction which covalently modifies beta-peptide is encountered with formic acid. In this report, fast atom bombardment mass spectrometry and tandem mass spectrometry demonstrate that both Ser8 and Ser26 become O-formylated in 70% aqueous formic acid solutions. The implications of this O-formylation upon the aggregational properties of beta-peptide are discussed.

Amino Acid Sequence↗
PubMed1992

Tandem mass spectrometric analysis of peptides at the femtomole level.

In the sequential analysis of peptides by fast atom bombardment (FAB) tandem mass spectrometry (MS/MS), the principal obstacle to decreasing sample quantities was determined to be the signal-to-background ratio of the ionization/desorption process. By decreasing the background ion current, continuous-flow FAB allows complete analysis (both MS and MS/MS) to be performed on 25-75% less sample than required for a conventional FABMS/MS experiment alone. The combination of CF-FAB with array detection permitted sequential analysis of several peptides (900-2000 Da) at the 900 fmol to 5.8 pmol level, without interference from the background. These levels do not produce a molecular ion species easily discernible above the background in conventional FAB.

Amino Acid Sequence↗
PubMed1992

Primary sequence confirmation of the beta-amyloid peptide from hereditary cerebral haemorrhage with amyloidosis (Dutch type) by collisional activation of the doubly charged ion.

High-energy collisional activation of doubly charged peptide ions allows direct sequential analysis of peptides over 4 kDa, including leucine/isoleucine determinations. This technique was used to verify the sequence of an intact beta-amyloid peptide associated with hereditary cerebral haemorrhage with amyloidosis Dutch type (4.2 kDa), which resists both enzymatic digestion and Edman sequencing. Additionally, this approach shows promise for the primary sequence confirmation of a wide variety of large peptides by tandem mass spectrometry.

Amino Acid Sequence↗
PubMed1992

Fragmentation studies of peptides: the formation of y ions.

The mechanism for the formation of y ions in the collision-induced dissociation (CID) spectra of protonated peptides produced by fast-atom bombardment was investigated by tandem mass spectrometry and deuterium labelling studies. The results show that a hydrogen atom attached to nitrogen and not to carbon migrates during cleavage of the amide bond. A mechanism based on these results is presented.

Amino Acid Sequence↗
PubMed1992

Validation of respiratory mechanics software in microprocessor-controlled ventilators.

BACKGROUND AND METHODS: Several microprocessor-controlled ventilators, available for clinical use, contain optional computer software programs capable of performing near-instantaneous determinations of airway resistance and lung compliance. This study was undertaken to determine the validity of the measurements for airway resistance and lung compliance obtained by the software packages on three microprocessor-controlled ventilators. Three ventilator models were studied. An artificial ventilator-patient circuit was constructed using a test lung and an endotracheal tube. Airway pressure and gas flow curves were recorded using conventional means. Static lung compliance and airway resistance were calculated using standard equations, while automated measurements were obtained from the ventilators. The following parameters were then varied to simulate a wide variety of clinical situations: tidal volume, peak inspiratory flow rate, respiratory rate, endotracheal tube, and test lung compliance. RESULTS: Automated measurements were highly correlated with values obtained manually (resistance: Puritan-Bennett 7200a r2 = .94, Bear 5 r2 = .98, Veolar r2 = .96; compliance: 7200a r2 = .93, Bear 5 r2 = .97, Veolar r2 = .97). Calculated limits of agreement between the two methods demonstrate that although not in absolute agreement, the software-determined values for airway resistance and lung compliance differed from the manually derived values in a ventilator-specific, predictable fashion. CONCLUSIONS: The correlation and agreement demonstrated between values of airway resistance and lung compliance measured by the respiratory mechanics software packages and those values derived manually suggest that these software packages may be useful for measuring trends, as well as responding to treatment in the clinical setting. These results apply only to the controlled, mechanical ventilation mode. Further studies are indicated to validate this software in patients capable of generating spontaneous breaths.

Airway Resistance↗
PubMed1992

Oral disposition kinetics of ofloxacin in patients with compensated liver cirrhosis.

The disposition kinetics of ofloxacin, a quinolone antibacterial agent excreted essentially unmodified by the kidney, was studied after single oral administration in 8 patients with compensated liver cirrhosis and in 8 control subjects. Mean elimination half-life and apparent volume of distribution were significantly increased in the cirrhotic group (7.6 vs. 4.9 h and 1.6 vs. 1.2 liters kg-1, respectively). A reduction in the renal clearance of ofloxacin was also observed in the cirrhotic patients, in spite of an apparently normal renal function. These observations indicate that also the pharmacokinetics of unmetabolized drugs may be altered in compensated liver cirrhosis. The serum concentration-time profiles of nearly all subjects exhibited a secondary peak 4-6 h after dosing. This double-peak behavior was interpreted as either enterohepatic circulation or biphasic gastric emptying of ofloxacin.

Administration, Oral↗
PubMed1991

Ultrasonographic findings of testicular microlithiasis associated with intratubular germ cell neoplasia.

Testicular microlithiasis is an uncommon condition in which calcified concretions fill the lumina of seminiferous tubules. We report the case of a twenty-three-year-old white man with a metastatic germ cell tumor and normal findings on testicular physical examination, but abnormal ultrasonography of the right testis. Orchiectomy revealed intratubular germ cell neoplasia with testicular microlithiasis. Multiple circular echogenic foci on ultrasound correlated with the histologic finding of testicular microlithiasis. Further studies are indicated for assessing ultrasonography as an adjunct for screening the population at risk for intratubular germ cell neoplasia.

Adult↗
PubMed1991

Effect of Silibinin on biliary lipid composition. Experimental and clinical study.

The effect of Silymarin, a natural flavonoid, on biliary lipid composition, was studied in rats and humans. Bile flow, biliary cholesterol, phospholipid and total bile salt concentrations were measured in 23 control rats and in 27 rats treated with Silibinin, the active component of Silymarin, at the dose of 100 mg/kg body weight i.p. (n = 21) or 50 mg/kg body weight i.p. (n = 6) for 7 days. Biliary cholesterol and phospholipid concentrations were significantly reduced after the higher Silibinin dose (60.9 and 72.9% of the control values), whereas bile flow and biliary total bile salt concentration were unchanged. After the lower Silibinin dose all parameters remained unchanged. Total liver cholesterol content was not affected by Silibinin. On the other hand, in vitro determination of rat liver microsomal 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase activity showed a significant dose-dependent inhibition by Silibinin (0.5-8 mg/kg). Biliary lipid composition was also assayed in four gallstone and in 15 cholecystectomized patients before and after Silymarin (420 mg per day for 30 days) or placebo administration. In both groups, biliary cholesterol concentrations were reduced after Silymarin treatment and the bile saturation index significantly decreased accordingly. These data suggest that Silibinin-induced reduction of biliary cholesterol concentration both in humans and in rats might be, at least in part, due to a decreased synthesis of liver cholesterol.

Adult↗
PubMed1991

Blood in saliva of HIV seropositive drug abusers: possible implication in AIDS transmission.

We have studied hemoglobin concentration in saliva of anti-HIV positive and anti-HIV negative intravenous drug abusers (IVDA) and normal controls and the relationship between hemoglobin concentration in saliva and number of CD4+ cells and clinical status of AIDS in anti-HIV positive IVDA. 120 anti-HIV positive IVDA, 112 anti-HIV negative IVDA and 116 normal healthy subjects not belonging to any risk group for HIV infection completed the study. Saliva was collected at awakening before brushing teeth and the concentration of hemoglobin was determined. Hemoglobin concentration in saliva in basal conditions is higher in anti-HIV positive IVDA with respect to anti-HIV negative IVDA (p less than 0.05) and controls (p less than 0.01). In anti-HIV positive IVDA hemoglobin concentration in saliva is higher in subjects with CD4+ cells less than 200/10(6) l with respect to subjects with CD4+ greater than 200/10(6) l (p less than 0.05) and in subjects with ARC/AIDS with respect to subjects with PGL or who are asymptomatic (p less than 0.01). Subjects with ARC/AIDS have a mean concentration of hemoglobin of 19 micrograms/0.1 ml saliva (range 0-153) which corresponds to 1.3 microliters of blood/ml saliva. If 10 ml of saliva are exchanged during kissing an average of 13 microliters of blood are transferred (110 microliters of whole blood at extreme range). Blood of symptomatic patients has an HIV titer of 7 TCID/microliters which for 10 ml saliva containing an average of 1.3 microliters blood/ml saliva corresponds to an average of 90 TCID (770 TCID at the extreme range).(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1991

Choledochal cyst diagnosed in pregnancy.

A primigravid patient with a type 1 choledochal cyst is reported. Conservative management allowed completion of the pregnancy and vaginal delivery of a term infant. Postpartum, the choledochal cyst was excised and biliary tree drained. A review of the literature and discussion of management alternatives of choledochal cysts discovered during pregnancy is presented.

Adult↗
PubMed1990

Effect of age on single- and multiple-dose pharmacokinetics of erythromycin.

The effect of age on the pharmacokinetics of erythromycin was investigated by comparing its kinetic behaviour in eight young healthy adults and eight healthy elderly subjects after single and repeated oral doses of erythromycin stearate 1 g b.d. for 7 doses. The peak serum concentration and area under the serum concentration-time curve (AUC) were significantly greater in the elderly subjects than in the young controls after single and multiple doses. Accordingly, the apparent oral clearance was lower in the elderly subjects (0.31 vs 0.64 and 0.22 vs 0.69 l.h-1.kg-1 after the first and seventh administration, respectively). The mean elimination half-life was significantly longer in the elderly group only after multiple dosing (4.8 vs 2.3 h). No age-related difference was observed in the time to peak serum concentration and apparent volume of distribution. The multiple-dose regimen resulted in an almost two-fold accumulation of erythromycin in the older individuals and no accumulation in the young adults. Mean drug accumulation in elderly subjects at steady state was 43% greater than was predicted from the AUC after the first dose, suggesting a time-dependent reduction in both systemic and presystemic clearance. The results indicate that the metabolic elimination processes for erythromycin are impaired in normal elderly subjects and suggest that caution is required on administering a high dose of it to aged people.

Adult↗
PubMed1990

Does pH paper accurately reflect gastric pH?

The testing of gastric pH in the ICU has become the standard of care for most critically ill patients. It has been demonstrated that maintaining a gastric pH of greater than 3.5 confers protection from upper GI bleeding, while lesser pH values subject the patient to hemorrhagic risk. We compared nasogastric pH, as measured by pH electrode, to color-scaled pH paper in 16 critically ill patients hospitalized 3 to 10 days in the surgical ICU. Statistical analysis of 370 gastric specimens revealed a sensitivity of 66.7% and specificity of 94.5% when a paper pH (pH[p]) of greater than or equal to 4 was used as the therapeutic end-point. The sensitivity and specificity of the same pH(p) for clear buffered solutions were 100%. We conclude that the use of pH(p) lacks the clinical accuracy for determining the effects of therapy for the prophylaxis of stress gastritis and will lead to a significant degree of undertreatment. This lack of accuracy is not due to observer error or the quality or age of the testing paper. Our results suggest that if the measurement of gastric pH by pH(p) analysis is to be used as a guide for the prevention of stress-related hemorrhage, a more accurate method of monitoring may be warranted.

Critical Care↗
PubMed1990

[Malaria prevention: new indications].

Malaria chemoprophylaxis must be continuously modified because of drug-resistant Plasmodium strains. The authors report the most recent regimens in all travelers including infants and pregnant women. The side effects of these drugs are pointed out.

Adult↗
PubMed1990

[An update on the therapy of malaria].

The authors analyze the recent treatment regimens of malaria, related to Plasmodium strains and clinical manifestation. Chloroquine is the first choice drug for uncomplicated chloroquine-sensitive P. falciparum, whereas for P. malariae, P. vivax and P. ovale infections treatment with chloroquine plus primaquine is also recommended. For uncomplicated chloroquine-resistant P. falciparum infections many treatment regimens are available. Management of complications is also analyzed.

Animals↗
PubMed1990

[Malaria epidemiology].

The investigators examine the worldwide epidemiological aspects of malaria infection, stressing the importance of possible alternative pathways of Plasmodium transmission in countries considered free of infection. The potential danger due to the persistence in Italy of the Anopheles mosquito, which could resume its role as a vector of Plasmodium in the future, is pointed out.

Animals↗