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Biomedical subjects

R Greco

Publications and source records attributed to R Greco.

At least 73 records · Page 4Linked to original sources
PubMed1996

The FcgammaRII receptor triggers pp125FAK phosphorylation in platelets.

Platelets express a single low affinity receptor for immunoglobulin, FcgammaRII, that triggers multiple cellular responses upon interaction with multivalent immune complexes. In this study we show that immobilized IgG is also a potent stimulant of platelet activation triggering adhesion, aggregation, massive dense granule secretion, and thromboxane production. Platelet adhesion to IgG was blocked by the FcgammaRII receptor-specific monoclonal antibody, IV. 3. Pretreatment of the platelets with cytochalasin D to inhibit actin polymerization similarly prevented cell binding to IgG having no effect on platelet binding to fibrinogen. Platelet adhesion to IgG also led to the induction of tyrosine phosphorylation of multiple proteins including pp125(FAK) and p72(SYK). These proteins were also tyrosine-phosphorylated in alphaIIbbeta3-deficient IgG-adherent platelets from patients with Glanzmann's thrombasthenia. These data demonstrate that FcgammaRII mediates pp125(FAK) phosphorylation and platelet adhesion to IgG independent of the integrin alphaIIbbeta3. Treatment of the platelets with bisindolylmaleimide to inhibit protein kinase C prevented phosphorylation of pp125(FAK) as well as several other proteins, but not p72(SYK) phosphorylation. This study establishes that the FcgammaRII receptor mediates pp125(FAK) phosphorylation via protein kinase C.

Antibodies, Monoclonal↗
PubMed1996

Left ventricular filling pattern in uncomplicated obesity.

To determine if uncomplicated obesity is associated with systolic dysfunction or impairment of left ventricular (LV) filling, 40 normotensive, white, asymptomatic, obese subjects (16 men and 24 women, mean +/- SD age 35 +/- 13 years; body mass index 36 +/- 6 kg/m2) and 40 normotensive, normal-weight, white volunteers matched for age and sex distribution, were studied by Doppler echocardiography. Endocardial and midwall shortening did not show differences between groups (obese = 33 +/- 4% and 17 +/- 2%; normal weight = 33 +/- 3% and 18 +/- 2%, respectively). LV mass index was higher in obese than in normal-weight subjects (p <0.0001). Obese persons had prolonged isovolumic relaxation time (p <0.0001), lower transmitral peak early diastolic filling wave (E) velocity (p <0.02), higher E velocity deceleration time (p <0.002) and lower E/atrial diastolic filling wave (A) flow velocity ratio (p <0.01) than did normal-weight subjects, even after controlling for age and blood pressure. Between-group differences in E and E velocity deceleration time disappeared when controlling for LV mass index, whereas prolonged isovolumic relaxation time in obesity was independent of LV mass, chamber dimension, and end-systolic stress. LV filling variables were not statistically related to endocardial or midwall shortening, both as absolute value or as a percentage of that predicted from wall stress. We conclude that uncomplicated obesity is associated with primary impairment of LV isovolumic relaxation; abnormalities of early passive filling flow in obesity are associated with increased LV mass.

Adult↗
PubMed1996

Spontaneous biliary perforation: does external drainage constitute adequate therapy?

Spontaneous perforation of the biliary tract in infancy is rare; fewer than 100 cases have been reported. The authors report on two patients with spontaneous biliary perforation (SBP) who were treated during the past 5 years. One of the patients, a 10-month-old boy, presented with an extensive retroperitoneal mass, without jaundice. He was found to have a perforation in the pancreatic portion of the common bile duct (CBD). The second patient, a 6-week-old boy, had insidious onset of jaundice, abdominal distension, and acholic stools. He was found to have a perforation at the cystic duct/CBD junction and distal CBD stricture. Both patients initially underwent cholecystostomy and drainage. The second patient had a persistent external biliary fistula and high-grade stricture, and subsequently underwent CBD excision and Roux-en-Y hepaticojejunostomy, at age 12 weeks. The authors' findings do not support the widely held concepts proposing that (1) the diminished distal ductal caliber often associated with these lesions occurs secondary to the perforation rather than is a primary causative factor and (2) the distal biliary obstruction does not require treatment because it resolves with adequate drainage. In the absence of ductal abnormalities, the authors advocate external drainage. For SBP associated with an underlying stricture, prompt biliary intestinal bypass is necessary to avoid biliary cirrhosis and portal hypertension.

Bile Duct Diseases↗
PubMed1996

Surgical treatment of spasmodic torticollis: is there a role for microvascular decompression? With an illustrative case report.

Spasmodic torticollis (ST) is a puzzling movement disorder, characterized by involuntary tonic or clonic contractions of various neck muscles. From time to time, psychogenic, extrapyramidal and neuroperipheral origins have been postulated and reflecting the variety of theories proposed, as many different treatments have been attempted, none of which has shown absolute effectiveness. Surgery of ST classically includes destructive procedures such as myotomies, stereotactically placed lesions, rhizotomies and neurectomies. The recent application of the concept of "neurovascular conflict" to ST induced several authors to perform microvascular decompression (MVD) in these patients, with encouraging and in some cases long-lasting results. Our case report joins this group. From the analysis of pertinent literature we conclude that: a. Spasmodic torticollis is probably a collection of separate clinical entities; b. Even in the so-called "ST of neuroperipheral origin" some coexising central factor must be admitted; c. Neurovascular compression underlies at least some cases of ST. Historical, anatomical, physiopathological and clinical aspects of ST are extensively discussed.

Decompression, Surgical↗
PubMed1995

Invasion of cultured human cells by Streptococcus pyogenes.

The invasive capacity of streptococcal strains belonging to groups A and B was evaluated by infecting human epithelial and endothelial cells and monitoring the number of viable intracellular bacteria at different times postinfection. All strains tested entered eukaryotic cells (HeLa, HEp2 and HUVE), with Streptococcus pyogenes exhibiting a higher invasion efficiency than group B streptococci (GBS). No intracellular multiplication was observed, and GBS remained viable 24 h postinfection, whereas S. pyogenes were gradually killed. We found that cytochalasin D almost completely inhibited internalization of all bacterial strains, whereas colchicine had no effect, indicating that host microfilaments play a major role in bacterial internalization. Moreover, the use of the lysosomotropic agent ammonium chloride enabled us to demonstrate that a pH increase in the intracellular vesicles did not affect streptococcal entry. These results were documented by electron microscopic observations which revealed the different steps in the invasion pathway, including a fusion event between phagosomes containing S. pyogenes and lysosomes.

Ammonium Chloride↗
PubMed1995

Celebrating the centennial (1894-1994): Leonardo Gigli and his wire saw.

In spite of the recent introduction of craniotomes in neurosurgical practice, the simple but brilliant wire saw invented by Leonardo Gigli still holds an important place in neurosurgical instrumentation. Born in Florence in 1863, Gigli was forced by circumstances to leave Italy soon after getting his medical degree. He first spent 2 years attending the most celebrated obstetrical clinics in Paris and London and then, in 1892, moved to Breslau where he worked with Fritsch and Mikulicz. During this successful and rewarding period, Gigli proposed the lateralized pubiotomy (Gigli's operation) for safe delivery in cases of maternal pelvic deformities and, inspired by the sight of a jagged knife during a country banquet, conceived his wire saw to simplify the procedure. In 1894, at Professor Obalinski's suggestion, he successfully tested a modified saw type with a whalebone guide for the preparation of osteoplastic cranial flaps. In spite of his great popularity and the high esteem in which he was held abroad, Gigli's aims were systematically belittled in Italy, where he never qualified for a university teaching position. He died in 1908, at age 44. Although the once celebrated Gigli's operation has merely historical interest today, the favorable features of his wire saw make it a safe and efficient tool in the hands of twentieth-century neurosurgeons worldwide.

History, 19th Century↗
PubMed1995

[Treatment of leg ulcers with fibrin glue].

The work is based on two years studied cases. It consists of 80 patients between 35 and 80 years old with leg ulcers (73.8% women and 26.2% men). In 80% of patients this affection is due to a venous disease. In 10% of cases the cause was an arterial insufficiency of the lower extremity. Lymphatic and extravascular diseases are rarely involved. A group of 54 patients was treated with a traditional method. In the remaining 26 patients we used fibrin glue. Leg ulcers are an evolutive chronic pathology characterized by slow recovery. This means expensive social and therapeutic costs. From this point of view the treatment with fibrin glue, weekly applied, besides reducing pain, has a favourable impact on the outcome, times of re-epithelialization are shortened.

Adult↗
PubMed1994

Treadmill exercise in Neopolitan children and adolescents.

Two hundred and eighty healthy children from Naples, Italy (140 boys and 140 girls) aged 4-17 years were studied using Bruce walking treadmill protocol to voluntary exhaustion. Endurance time and double product increased with age. Systolic blood pressure increased linearly during the test. Multivariate analysis showed that body weight and age were the best predictors of endurance time. Endurance time averaged 15.2 +/- 2.8 min in boys and 13.7 +/- 2.3 min in girls (p = 0.00001). Mean +/- SD double product at peak exercise was 264.3 +/- 63 (boys) and 242 +/- 44 (girls) (p = 0.01). Sinus arrhythmia was present in 78% of the children and disappeared at a mean heart rate of 112 +/- 16 beats/min during exercise. The voltage of the R wave on V4 lead decreased in all but four children during the test (delta R = -0.25 +/- 0.24 mV). The P and T waves increased in almost all children. No ST depression or upward sloping was detected. The voltage of the PR isoelectric line remained constant. The J point was displaced downwards in 78% of children, unchanged in 11% and displaced upwards in the remaining 11% of the children. The present study gives reference parameters for a walking treadmill test in Southern European children.

Adolescent↗
PubMed1994

[Continuous venous infusion of buprenorphine with autonomous elastomeric system in the control of postoperative pain].

We herein evaluated the analgesic effectiveness of low doses of buprenorphine with or without a primer and the practicality and usefulness of a constant flow disposable infusion set (Infusor Baxter 2 ml/h). Our series consists of 300 patients, seen between January 1992 and December 1993, randomly distributed in three groups of 100 patients each. All patients were informed before operation about the use of pain Visual Analogical Scale (VAS) and how the infusor works. At the end of the operation all patients had an infusor positioned with a 0.01 mg/kg supplied of buprenorphine diluted to 60 ml with Ringer's Lactate solution. In addition to this, group B patients received an i.v. primer of 0.003 mg/kg of buprenorphine diluted to 10 ml with saline solution and group C patients received an i.v. primer of 0.5 mg/kg of ketorolac diluted to 10 ml with saline solution. VAS, systolic arterial pressure, diastolic arterial pressure, heart rate, respiratory rate, request of analgesics and side effects were evaluated at one hour (T0), six hours (T1), 12 hours (T2), 24 hours (T3) and 36 hours (T4) after operation. Group B and C patients showed significant reduction in VAS compared to group A patients at T0 and T1 but the difference disappeared starting from T2. Group B and C patients showed blood pressure, heart rate and respiratory rate values significantly reduced compared to group A patients at T0 and T1. Such values however then stabilized. Side effects encountered were nausea and vomiting in different percentages in the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Postoperative analgesia: peridural morphine versus sublingual buprenorphine. Comparative clinical study].

The authors herein present their personal series on the clinical evaluation of the analgesic efficacy of 2 opiodes, peridural morphine hydrochloride (0.5 mg/kg) administered to group A patients, and sublingual buprenorphine (0.4 mg) administered to group B patients in the management of post-operative pain in major abdominal surgery. The study was conducted on 44 patients, both male and female, classified as ASA II and III. Statistical analysis of cardiovascular parameters (BP and cardiac frequency), respiratory frequency and pain score showed an overlapping progression among the two groups. Spontaneous pain decreased significantly to zero at T6 (p < 0.001). However, the necessity to administer buprenorphine more frequently after the sixth hour and the consequent increase in side effects, lead us to believe that the method used for group A patients is more advantageous.

Administration, Sublingual↗
PubMed1994

Cruciate paralysis from a Jefferson's fracture. Report a case and review of the literature.

A case of post-traumatic cruciate paralysis with a Jefferson's fracture was observed in a 54-year-old patient who fell accidentally. Cruciate or Bell's paralysis is a condition caused by incomplete cervical spinal cord lesion linked to focal and reversible damage of the pyramidal tract at the level of the decussation. The patient was treated by S.O.M.I. brace and a Philadelphia collar with a complete neurological restitution.

Cervical Atlas↗
PubMed1993

[Inguinal hernioplasty by a modified Shouldice technic. Our experience with 350 treated cases].

A statistical analysis of 340 patients operated between 1986 and 1991 for inguinal hernia using the Shouldice procedure are reported by the authors. The majority of patients (60%) treated was between 45 and 65 years old. Two-hundred-eighty-one (82%) were controlled with a mean follow-up of 30 months (range 1-6 years) and was executed with physical examination and a medical questionnaire looking for recurring factors of risk. Hundred-twenty-eight patients (45% of controls) were at the high risk, nevertheless hernia recurrences were not noticed. Postoperative course was uncomplicated in 93% of patients. Early or late loco-regional complications had an incidence of 7%. Local infections and edema were reported in 10 of 22 patients. Acute urinary retention, cephalalgia and hypotension correlated with an anesthesiologic method had an incidence of 5% (17 cases). There were no deaths was pulmonary embolisms. A review of literature was performed and compared with our work. From experience in our Division, Shouldice's hospital technique had a high reliability compared to methods utilized in the previous ten years (Bassini, McNealy, Postemskj, Mugnai-Ferrari), in terms of recurrences.

Adolescent↗
PubMed1993

Role of calcium in chloride secretion mediated by cAMP pathway activation in rabbit distal colon mucosa.

Effects of Ca2+ on adenosine 3',5'-cyclic monophosphate (cAMP)-mediated Cl- secretion were investigated in intact mucosa and isolated crypt cells of rabbit descending colon. Addition of 10 microM prostaglandin (PG)E2 or forskolin to tissues incubated in Ca(2+)-free medium increased the size of short-circuit current (Isc) and Cl- secretion as estimated by unidirectional 36Cl flux measurements (net flux = -2.31 +/- 0.24 vs. -1.22 +/- 0.10 mueq.h-1.cm-2, n = 4, P < 0.001). Addition of 10 microM PGE2 to tissues incubated in 1.2 mM Ca2+ Ringer induced a 7-fold increase in mean cAMP level, whereas it produced an 11-fold increase in tissues exposed to Ca(2+)-free medium. Membrane preparations from whole mucosa incubated in Ca(2+)-free medium displayed a cyclic nucleotide phosphodiesterase activity significantly lower than controls (18.76 +/- 0.54 vs. 31.20 +/- 0.39 pmol cAMP. mg protein-1.min-1, means +/- SE, n = 4, P < 0.001). Ca2+ removal also affected adenylate cyclase (AC) responsiveness to agonists; AC activity increased in controls by 54 and 226% after stimulation with 10 microM PGE2 and forskolin, respectively, but it increased more (77 and 325%, respectively) after incubation in Ca(2+)-free solutions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenylyl Cyclases↗
PubMed1992

Assessment of the pharmacy service needs of HIV-positive outpatients receiving zidovudine.

OBJECTIVE: To determine the pharmacy service needs of HIV-positive outpatients. DESIGN: Anonymous mail-in survey. SETTING: Accredited, not-for-profit, outpatient pharmacy. PATIENTS: A total of 226 men receiving refill prescriptions for zidovudine. Relevant demographics: for 91 percent, homosexual behavior was the primary HIV risk factor; 75 percent were HIV positive with low CD4+ count; 68 percent had been receiving zidovudine for less than 12 months. MEASUREMENTS: Survey questions determined patients' past experience and satisfaction with pharmacy services, description of pharmacy service needs, drug history, and sociodemographics. MAIN RESULTS: Confidentiality was desired by 90 percent of patients. Patients also expected to receive private medication counseling on zidovudine routinely and to receive other information upon request. Twenty patients expected no medication counseling. Such patients were more likely to have contracted HIV by transfusion or intravenous drug abuse (p less than 0.05). CONCLUSIONS: The perceived pharmacy service needs of outpatients taking zidovudine can reasonably be met in all ambulatory settings. Pharmacists must be aware that all patients do not have the same needs and should tailor their activities to the needs expressed by individual patients.

Adolescent↗
PubMed1992

Antiflammins suppress the A23187- and arachidonic acid-dependent chloride secretion in rabbit distal colonic mucosa.

Antiflammins are synthetic peptides with sequence homology to proteins inhibitory for phospholipase A2. The effects of antiflammins on chloride secretion induced by the calcium ionophore A23187, arachidonic acid (AA) and prostaglandin E2 (PGE2) were investigated in distal rabbit colonic mucosa mounted in Ussing-type chambers. 100 nM AF-2 (antiflammin 2, peptide HDMNKVLDL) fully prevented the increase in Isc, net chloride secretion, tissue PGE2 and second messenger cAMP induced by 5 microM A23187. AF-1 (antiflammin 1, peptide MQMKKVLDS) also inhibited, although to a lesser extent, the A23187-mediated increase in Isc. AF-2 inhibition began at doses of 100 nM (delta Isc -0.20 +/- 0.08, microEq h-1 cm-2, mean +/- S.E.M., N = 3) and was maximal at doses comprised between 200 and 250 nM (delta Isc -0.51 +/- 0.12, microEq h-1 cm-2, mean +/- S.E.M., N = 3). AF-2 also inhibited the increase in Isc and chloride secretion induced by the incubation with 10 microM AA and bradykinin but it was ineffective when tissues were stimulated with 10 microM PGE2. 100 nM AF-2 brought about an inhibition of the increase in AA-mediated increases in PGs and cAMP comparable to that of 10 microM of the cyclooxygenase inhibitor indomethacin. In vitro assay of colonic cyclooxygenase activity showed that 100 nM AF-2 and AF-1 inhibited cyclooxygenase activity (73 and approximately 30%, respectively), but they did not modify the in vitro activity of porcine phospholipase A2.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗