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Biomedical subjects

G Rinaldi

Publications and source records attributed to G Rinaldi.

At least 19 recordsLinked to original sources
PubMed1995

Hepatitis C virus RNA in the bone marrow of patients with mixed cryoglobulinemia and in subjects with noncryoglobulinemic chronic hepatitis type C.

Hepatitis C virus (HCV) infection is associated with most mixed cryoglobulinemia (MC) syndromes. In this study, HCV RNA was detected in the peripheral blood mononuclear cells of 11 (73.3%) of 15 patients with MC and in 5 (71.4%) of 7 noncryoglobulinemic patients with chronic hepatitis type C. All patients with cryoglobulinemia and 3 (42.8%) of the 7 without cryoglobulinemia (P < .05) had HCV RNA in bone marrow cells. Subjects in both groups with HCV-positive bone marrow also had HCV RNA in serum. The majority of patients with MC syndromes were infected with HCV subtypes 1b and 2a. Two patients with MC had different genotypes in serum and cells. Further studies are needed to determine which bone marrow cell population is preferentially infected by HCV and to determine if this phenomenon is involved in inducing the production of cryoglobulins.

Aged↗
PubMed1995

Oscillatory potentials in subjects with treated hypertension.

Oscillatory potentials of the ERG proved to be a sensitive indicator even in mild disturbances of retinal circulation, such as the first stage of hypertensive retinopathy (WHO classification). Oscillatory indexes (OIs) and blood pressure levels of 24 hypertensive patients in stage 1 of the WHO classification, who underwent an antihypertensive therapy for the first time, were considered. The patients were retested after a mean period 8 months. a strict inverse correlation was found between OIs and blood pressure levels.

Adult↗
PubMed1994

Modern therapeutic approaches to postmastectomy brachial lymphedema.

Over the past 10 years we have treated 36 patients affected by upper limb lymphedema, associated with mastectomy and axillary dissection, by either macrosurgical exeresis or microsurgical techniques. All cases had been unresponsive to prior drug or physical therapy (pressure and thermal therapy). Preoperative upper limb status was thoroughly examined by evaluating volume measurements, dynamic lymphoscintigraphy, venous Doppler fluximetry, ultrasonography, and nuclear magnetic resonance. Selected tests were repeated during follow-up to obtain more statistically significant results. Twenty-five of the 36 patients in our series presented a grade II lymphedema and underwent Degni-Cordeiro's microsurgical indirect lymphatico-venous shunt (L.V.S.) surgery. Fifteen of the 25 also received fasciotomies performed along the posterior aspect of the forearm. Three of the 36 patients presented grade II lymphedema and upper limb venous hypertension. These were treated with multiple fasciotomies alone. The remaining eight patients presented grade III lymphedemas. Seven underwent Kondoleon's partial superficial lymphangectomy, and one was treated with Servelle's total superficial lymphangectomy. Of the 36 patients who underwent surgery, only 27 were checked at 6 months; 22 were seen at 18 months. The remaining patients were followed up for too short of a period of time to be considered. Results were arranged into three groups. Classification criteria were: reduction of upper limb dimensions and the presence of the pre-existing symptoms (episodes of lymphangitis, pain, functional deficits. Results were considered good (class 3), fair (class 2), or poor (class 1). A positive clinical picture (class 2-3) was seen in 74% (20/27) at 6 months and in 59% (13/22) at 18 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Arm↗
PubMed1994

Early and late results of 100 consecutive total gastrectomies for cancer.

The authors present a case study of 100 patients who underwent total gastrectomy out of a total of 376 patients submitted to surgery for gastric cancer between 1970 and 1992. The majority of the neoplasms were located in the middle third of the stomach with histological characteristics of an epithelial type in 92% of the cases, 8 of which were classified Stage IA, 6 Stage IB, 14 Stage II, 24 Stage IIIA, 25 Stage IIIB, and 15 at Stage IV. An R2 total gastrectomy, which included the distal 2-3 centimeters of the esophagus and the proximal 2-3 centimeters of the duodenum, combined with omentectomy and level 1 and 2 lymphadenectomy, was always performed. Thirty-four of the operations were extended and splenectomy was performed in 27 of these. Digestive continuity was obtained in 37 cases with an esophago-jejunostomy on a Roux-en-Y loop. Recanalization of the duodenum was accomplished in accordance with the Moricca technique in 32 cases and the Mouchet-Camey technique in 22 cases. Of the remaining 9, 5 underwent reconstructive surgery as described by Sweet-Allen, 2 as described by Nakayama, and the remaining 2 direct esophago-duodenostomy. The majority of the cases received total parenteral nutrition on the second postoperative day and this was maintained for the following eight days. Post-operative mortality, reported during the initial 30 days was 7%, overall morbidity 17%. A detailed protocol of clinical and diagnostic tests was established for follow-up studies conducted on a 4-month basis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1994

Relationship between baseline blood pressure and blood pressure decrease after calcium channel blockers in conscious rats.

OBJECTIVE: To determine whether vasodilators produce a fall in mean blood pressure (MBP) that is directly proportional to baseline MBP. DESIGN: The effects on blood pressure of three calcium channel blockers, nitrendipine, nisoldipine and verapamil, were compared with sodium nitroprusside, a drug acting through a different mechanism. The drugs were infused in conscious, unrestrained rats and their effect on MBP was measured. SETTING: Primary experimental. ANIMALS: Animals were divided into three groups according to their baseline MBP: high (greater than 119 mmHg), moderate (91 to 119 mmHg) and normal (less than 91 mmHg). INTERVENTIONS: Five successive infusion rates for each drug were tested in each animal. MBP readings were taken at the end of each infusion period (usually 10 mins). MAIN RESULTS: At the maximal dose infused, nitrendipine (0.57 mg/kg.min) lowered MBP 13 +/- 6 mmHg in the low MBP rats, 51 +/- 4 mmHg in the rats with moderate MBP and 83 +/- 8 mmHg in the rats with high MBP (P < 0.05 within groups). Similar results (ie, the greater the baseline MBP, the greater the fall in MBP) were obtained with nisoldipine and verapamil. In the same groups, sodium nitroprusside (0.096 mg/kg.min) produced a fall of 52 +/- 3 mmHg, 56 +/- 5 mmHg and 54 +/- 13 mmHg, respectively (not significant). CONCLUSIONS: Nitrendipine, nisoldipine and verapamil behave as antihypertensives since their effect increased as a function of the initial MBP, while sodium nitroprusside showed no effect related to baseline MBP.

Animals↗
PubMed1993

Contrast sensitivity in multifocal intraocular lenses.

Contrast sensitivity was measured in two groups of 20 patients each implanted with refractive and diffractive multifocal intraocular lenses and in two control groups of 20 patients each--the first group implanted with a monofocal IOL and the second phakic subjects. All cases had a postoperative follow-up of at least one year and a corrected visual acuity of 20/20- or better. We used two psychophysical tests, Pelli Robson test chart and Vistech 6500 test chart, and an objective test, visual evoked potentials (VEPs). There were no statistically significant differences in contrast sensitivity in the psychophysical tests between the two groups implanted with multifocal IOLs. The situation was different, however, when they were compared with the control group with monofocal IOLs and the group with phakic eyes: the Pelli-Robson test results were not significantly different, but the Vistech 6500 test showed a significant reduction in contrast sensitivity in both groups. The pattern VEPs objective test confirmed these results: no differences were noted between the two different multifocal IOLs, while there was a drop in contrast sensitivity when their results were compared with those of the control groups; the intermediate frequencies were particularly affected by this phenomenon. The contrast sensitivity in patients with multifocal IOLs is reduced despite high visual acuity and this can affect the quality of vision.

Aged↗
PubMed1992

High-dose immunoglobulin therapy as an immunomodulatory treatment of rheumatoid arthritis.

OBJECTIVE: To investigate the efficacy of high-dose intravenous immunoglobulin (IVIg) in the treatment of refractory rheumatoid arthritis (RA). METHODS: Ten patients with active, severe RA that was unresponsive to first- and second-line agents were administered IVIg monthly, for 6 months. RESULTS: Following IVIg treatment, there was significant improvement in both subjective and objective parameters of disease activity in all 9 patients who completed the protocol. This improvement was noted to occur as early as after the second infusion of IVIg. After discontinuation of the treatment, all patients had a relapse of the disease within a few weeks. CONCLUSION: Since the reduction in clinical activity paralleled a decrease in the CD4+CDw29+:CD4+CD45RA+ cell ratio, some of the therapeutic benefits associated with IVIg may be due to a direct influence on the CD4+CD45RA+ subset. Although the possibility of carrying out further controlled studies on a larger scale is limited by the high cost of the treatment, IVIg appears to be an effective therapy for refractory RA.

Adult↗
PubMed1990

Symptoms of respiratory allergies are worse in subjects with coexisting food sensitization.

Food sensitization was evaluated in 78 subjects with respiratory allergies, both by skin tests with commercial and fresh allergens, and by specific IgE determination. On the basis of the presence or absence of the latter the population was divided into two groups. The group with food-specific IgE showed more severe features of respiratory allergy, including a greater number of positive skin tests and specific IgE determinations, more class 3 and 4 reactions, and more symptoms. The hypothesis that early food sensitization can predispose to severe inhalant allergy is discussed.

Adult↗
PubMed1990

Considerations upon a non-typical anterior ischemic optic neuropathy.

The authors report the clinical history of a patient with bilateral oedema of the optic nerve head, visual field implication, fluorescein-angiographic and electrofunctional result disturbances, but with maintenance of a normal visual acuity. The etiopathogenetic hypothesis are prospected.

Aged↗
PubMed1990

Influence of norepinephrine-sensitive intracellular calcium stores on the relaxant response to diltiazem in rat aorta.

The contractile response to norepinephrine (NE) in rat aorta has an initial fast (F) component attributable to Ca release, followed by a slow (S) component due to Ca influx. The relaxant action of the Ca entry blocker Diltiazem (DT) 10 microns was measured in three different responses to NE: a) a NE contraction in Ca = 1.35 mM (in which both the F and S components participate) was relaxed by 36 +/- 4%; b) previous incubation with Prazosin 0.01 microM eliminated the F component. Only the S component appeared (with a force equal to that of the previous total response) and it was relaxed by DT by 47 +/- 3%; c) the intracellular Ca pool was depleted by exposure to NE in Ca-free solution + EGTA. Further exposure to Ca = 1.35 mM produced only an S component, which was relaxed by DT by 61 +/- 4%. Since the preceding experiments suggested that the relaxant effect of DT increased as the participation of the Ca pool in the NE response decreased, an intermediate situation was looked for. The Ca pool was depleted as in (c) and then it was partially refilled by brief exposure to Ca = 1.35 mM. DT relaxation decreased to 51 +/- 3% (20 sec of refilling) and to 41 +/- 3% (60 sec of refilling). Similar results were obtained with DT 0.1, 1 and 100 microM. It is concluded that the relaxant action of DT on a NE contraction in rat aorta is inversely related to the amount of NE-releasable intracellular Ca that contributed to that contraction.

Animals↗
PubMed1989

Potassium-induced relaxation of arteries in hypertension: modulation by extracellular calcium.

Smooth muscle relaxation due to activation of Na+-K+-adenosinetriphosphatase (ATPase) (K+ relaxation) was studied in isolated tail arteries from stroke-prone spontaneously hypertensive (SHRSP) and Wistar-Kyoto (WKY) rats. Exposure to K+ (7 mM) relaxed a norepinephrine (1 microM) contraction induced in K+-free physiological salt solution (PSS) by 46 +/- 3% in WKY and by 81 +/- 3% in SHRSP. Incubation with monensin (10 microM) augmented the K+-relaxation in WKY to 61 +/- 5%. Incubation with amiloride (10 microM) or with low-Na+ (10 mM) PSS attenuated the K+ relaxation in SHRSP to 34 +/- 3 and 5 +/- 2%, respectively. Incubation with high-Ca2+ (6.6 mM) PSS attenuated the K+ relaxation in WKY to 25 +/- 3% but resulted in only a slight decrease in the relaxation in SHRSP (to 73 +/- 2%). We conclude 1) that a greater Na+ leakiness of the plasma membrane in SHRSP than in WKY while the Na+ pump is inactive in K+-free PSS can explain the greater relaxation observed when the Na+ pump is reactivated and 2) that the Na+ leakiness of the membrane is more attenuated by Ca2+ in the WKY than in the SHRSP. We hypothesize that this Ca2+ effect reflects a normally large amount of this ion that can be bound to and thereby stabilize the membrane of the WKY, decreasing its permeability to Na+. The membrane of the SHRSP is deficient in its Ca2+-binding sites. Hence the added Ca2+ does not further stabilize its membrane.(ABSTRACT TRUNCATED AT 250 WORDS)

Amiloride↗
PubMed1989

Endothelium-mediated spontaneous response in aortic rings of deoxycorticosterone acetate-hypertensive rats.

Aortic rings isolated from normotensive Sprague-Dawley rats (CONT) exhibited spontaneous tone when the preparations were stretched. After administering deoxycorticosterone acetate (DOCA), the rats became hypertensive, and this spontaneous tone increased remarkably. The spontaneous tone was dependent on the extracellular calcium concentration. Incubation with the calcium entry blocker D-600 attenuated the spontaneous response to a greater degree in rings from DOCA rats than in rings from CONT rats. Nifedipine relaxed the already developed spontaneous tone. Removal of the endothelium greatly depressed spontaneous tone, but did not diminish the contraction caused by norepinephrine. On the basis of our findings, we conclude that 1) spontaneous tone depends on calcium influx, presumably through specific stretch-operated membrane channels, 2) these stretch-dependent channels are blocked by D-600 and nifedipine, 3) spontaneous tone is enhanced in DOCA hypertension, and 4) the endothelium appears to act as a receptor for stretch, mediating--at least in part--the spontaneous contractile response by releasing a constrictor agent.

Animals↗
PubMed1989

Captopril inhibits ouabain-sensitive Na+/K+-ATPase.

Captopril has been reported to inhibit ouabain-sensitive Na+/K+-ATPase activity in erythrocyte membrane fragments. We investigated the effect of captopril on two physiological measures of Na+/K+ pump activity: 22Na+ efflux from human erythrocytes and K+-induced relaxation of rat tail artery segments. Captopril inhibited 22Na+ efflux from erythrocytes in a concentration-dependent fashion, with 50% inhibition of total 22Na+ efflux at a concentration of 4.8 X 10(-3) M. The inhibition produced by captopril (5 X 10(-3) M) and ouabain (10(-4) M) was not greater than that produced by ouabain alone (65.3 vs. 66.9%, respectively), and captopril inhibited 50% of ouabain-sensitive 22Na+ efflux at a concentration of 2.0 X 10(-3) M. Inhibition by captopril of ouabain-sensitive 22Na efflux was not explained by changes in intracellular sodium concentration, inhibition of angiotensin-converting enzyme or a sulfhydryl effect. Utilizing rat tail arteries pre-contracted with norepinephrine (NE) or serotonin (5HT) in K+-free solutions, we demonstrated dose-related inhibition of K+-induced relaxation by captopril (10(-6) to 10(-4) M). Concentrations above 10(-4) M did not significantly inhibit K+-induced relaxation but did decrease contractile responses to NE, although not to 5HT. Inhibition of K+-induced relaxation by captopril was not affected by saralasin, teprotide or indomethacin. We conclude that captopril can inhibit membrane Na+/K+-ATPase in intact red blood cells and vascular smooth muscle cells. The mechanism of pump suppression is uncertain, but inhibition of ATPase should be considered when high concentrations of captopril are employed in physiological studies.

Animals↗
PubMed1988

Plasma membrane and its abnormalities in hypertension.

The plasma membrane is composed of proteins embedded in a discontinuous fashion in a lipid bilayer. These proteins maintain the integrity of the membrane and play fundamental roles as ion transport channels and as receptors for agents that regulate cell function. The membrane is therefore an important regulator of vascular smooth muscle contraction. The plasma membrane in the hypertensive animal exhibits abnormal permeability for monovalent ions and defective calcium handling. This is reflected in fewer calcium-binding sites and, as a result, in deficient membrane stabilization. These defects have been identified in several cell types, including lymphocytes, red blood cells, adipocytes, and vascular smooth muscle cells. Evidence presented in the current review suggests that hypertension is associated with a generalized membrane defect. Abnormalities in ion transport in vascular smooth muscle cells are the most relevant to the pathogenesis of hypertension since they could be directly responsible for the rise in blood pressure. We hypothesize that the impaired stabilizing effect of calcium in vascular smooth muscle cells of hypertensive subjects renders the membrane more excitable and that this in turn leads to increased vascular reactivity and higher peripheral resistance. Peripheral vascular reactivity usually is increased in hypertension, suggesting increased responsiveness of the smooth muscle cells. Possible abnormalities of the several components of the contractile process of these cells have been investigated for the role they might play in this altered response. Abnormalities in the plasma membrane have been most clearly defined and are emphasized in this review.

Animals↗
PubMed1986

[Essential arterial hypertension: main vasodilator effect of nifedipine].

The acute effects of a single dose of nifedipine (NIF, 20 mg SL) on heart rate (HR), arterial pressure (AP), forearm blood flow (FBF) and forearm vascular resistance (FVR), were measured in 15 normotensive (NP) and 11 hypertensive (HP) patients. In NP, NIF increased HR (from 78 +/- 3 to 88 +/- 3 lat/min, P less than 0.05) and FBF (from 4.0 +/- 0.4 to 5.5 +/- 0.3 ml/min. 100 ml, P less than 0.05) and decreased AP (from 99 +/- 2 to 89 +/- 3 mmHg, P less than 0.05) and FVR (from 29 +/- 3 to 22 +/- 2.9 relative units, P less than 0.05). In HP the changes were (with the exception of HR, which did not vary significantly) much greater in magnitude, and directly correlated with pretreatment levels of AP. In vitro experiments in aortic rings from spontaneously hypertensive (SHR) and normotensive (NR) rats demonstrated a much greater sensitivity of SHR to the relaxant effect of NIF, while the relaxant effect of nitroglycerin was similar in NR and SHR. It is concluded that NIF, although acting preferentially in HP as a hypotensive drug, also exerts a slight but still significant effect in NP. The greater vasodilating effect in HP could be due to a supersensitivity of the smooth muscle cell to NIF, possibly located at the calcium influx level.

Animals↗
PubMed1984

A report of seven long survivors for evidence of prognostic factors in hairy cell leukemia.

The clinical hematologic and pathologic findings of 30 patients with hairy cell leukemia observed between 1966 and 1979 were studied. Twelve patients had long-lasting course of the disease. Seven of them displayed a survival greater than or equal to 120 months, whereas 18 patients died within 36 months of the diagnosis. Their clinical and laboratory characteristics (age of onset, sex, ESR, hemoglobin, WBC, neutrophils, monocytes, platelets, spleen and liver size) were analyzed to ascertain possible prognostic features. Multivariate discriminant analysis, performed both with a direct method and with a stepwise method (Wilks' method), provided a discriminant function able to correctly predict the prognosis of the disease in 83.3% of the examined cases. Spleen size, neutrophil count, age of onset, ESR and liver size turned out to be the most important prognostic factors; in contrast, splenectomy did not significantly affect the prognosis in our cases.

Adult↗