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Biomedical subjects

P Damiani

Publications and source records attributed to P Damiani.

At least 19 recordsLinked to original sources
PubMed1998

Antimould activity of sourdough lactic acid bacteria: identification of a mixture of organic acids produced by Lactobacillus sanfrancisco CB1.

Sourdough lactic acid bacteria, cultivated in wheat flour hydrolysate, produced antimould compounds. The antimould activity varied greatly among the strains and was mainly detected within obligately heterofermentative Lactobacillus spp. Among these, Lb. sanfrancisco CB1 had the largest spectrum. It inhibited moulds related to bread spoilage such as Fusarium, Penicillium, Aspergillus and Monilia. A mixture of acetic, caproic, formic, propionic, butyric and n-valeric acids, acting in a synergistic way, was responsible for the antimould activity. Caproic acid played a key role in inhibiting mould growth.

Antifungal Agents↗
PubMed1997

Calcium, calcium release receptors, and meiotic resumption in bovine oocytes.

During maturation, mammalian oocytes undergo a series of changes that prepare them for fertilization. These events are regulated by kinases, most notably histone H1 and mitogen-activated protein kinase. Intracellular calcium ([Ca2+]i) oscillations participate in oocyte signaling, and it has been postulated that they play a role in oocyte maturation. In these studies we investigated the association of Ca2+, Ca2+ channels, and activation of kinases in in vitro-maturating bovine oocytes. BAPTA-AM, a Ca2+ chelator, inhibited oocyte maturation and delayed activation of kinases, although spontaneous [Ca2+]i rises were not observed in control oocytes loaded with fura-2, a Ca2+ indicator. The ability of the 1,4,5-inositol trisphosphate receptor (InsP3R) to release Ca2+, monitored after the addition of thimerosal and myo-inositol 1,4,5-trisphosphate (InsP3), increased as maturation progressed. This may be associated with a similar increase, monitored by Western blotting, in the density of the type I InsP3R isoform during oocyte maturation. Injection of heparin, an InsP3R antagonist, blocked oocyte maturation and activation of kinases. The density of the ryanodine receptor, another Ca2+ channel, may be 30- to 100-fold lower than that of the InsP3R in bovine oocytes. Thus, our results demonstrate that [Ca2+]i participates in the progression of meiosis and that the InsP3R may be responsible for the majority of Ca2+ release during maturation and fertilization.

Animals↗
PubMed1996

Evaluation of developmental competence, nuclear and ooplasmic maturation of calf oocytes.

In this study we evaluated nuclear and ooplasmic maturation of prepuberal calf oocytes to determine a possible cause for their low developmental competency. Calf oocytes resumed meiosis and arrested at the MII stage at rates similar to that of adult animals; however, zygotes derived from calf oocytes cleaved and developed at significantly lower rates. Ooplasmic maturation was assessed during oocyte maturation and fertilization. Transmission electron microscopy revealed that a majority of calf oocytes exhibited some delay in organelle migration and redistribution following maturation. Immunofluorescence microscopy showed that following IVF, a higher percentage of calf oocytes had abnormal chromatin and microtubule configurations than those of adult cattle. These anomalies were characterized by delayed formation of sperm aster and asynchronous pronuclear formation. Microfluorometry was used to characterize the Ca2+ responses of calf oocytes to the addition of agonists or after IVF. The addition of thimerosal demonstrated the presence of Ca2+ stores in calf oocytes. Injection of near threshold concentrations of inositol 1,4,5-trisphosphate (InsP3), used to test the sensitivity of the InsP3R, released significantly less Ca2+ in calf than in cow oocytes, whereas higher concentrations of InsP3 (500 microM) released maximal [Ca2+]i in both oocytes. These results suggested that the Ca2+ content of intracellular stores was similar, but the sensitivity of the InsP3R may be different. Following insemination, calf oocytes exhibiting [Ca2+]i oscillations displayed comparable amplitude and intervals to cow oocytes; however, a significantly higher number of fertilized calf oocytes failed to show oscillations. Our findings suggest that the low developmental competence of calf oocytes can be attributed, at least in part, to incomplete or delayed ooplasmic maturation.

Animals↗
PubMed1995

Comparative study of biological glues: cryoprecipitate glue, two-component fibrin sealant, and "French" glue.

BACKGROUND: Although biological glues have been used clinically in cardiovascular operations, there are no comprehensive comparative studies to help clinicians select one glue over another. In this study we determined the efficacy in controlling suture line and surface bleeding and the biophysical properties of cryoprecipitate glue, two-component fibrin sealant, and "French" glue containing gelatin-resorcinol-formaldehyde-glutaraldehyde (GRFG). METHODS: Twenty-four dogs underwent a standardized atriotomy and aortotomy; the incisions were closed with interrupted 3-0 polypropylene sutures placed 3 mm apart. All dogs had a 3- by 3-cm area of the anterior wall of the right ventricle abraded until bleeding occurred. The animals were randomly allocated into four groups: in group 1 (n = 6) bleeding from the suture lines and from the epicardium was treated with cryoprecipitate glue; in group 2 (n = 6) bleeding was treated with two-component fibrin sealant; group 3 (n = 6) was treated with GRFG glue; group 4 (n = 6) was the untreated control group. The glues were also evaluated with regard to histomorphology, tensile strength, and virology. RESULTS: The cryoprecipitate glue and the two-component fibrin sealant glue were equally effective in controlling bleeding from the aortic and atrial suture lines. Although the GRFG glue slowed bleeding significantly at both sites compared to baseline, it did not provide total control. The control group required additional sutures to control bleeding. The cryoprecipitate glue and the two-component fibrin sealant provided a satisfactory clot in 3 to 4 seconds on the epicardium, whereas the GRFG glue generated a poor clot. There were minimal adhesions in the subpericardial space in the cryoprecipitate and the two-component fibrin sealant groups, whereas moderate-to-dense adhesions were present in the GRFG glue group at 6 weeks. The two-component fibrin sealant was completely reabsorbed by 10 days, but cryoprecipitate and GRFG glues were still present. On histologic examination, both fibrin glues exhibited minimal tissue reaction; in contrast, extensive fibroblastic proliferation was caused by the GRFG glue. The two-component and GRFG glues had outstanding adhesive property; in contrast, the cryoprecipitate glue did not show any adhesive power. The GRFG glue had a significantly greater tensile strength than the two-component fibrin sealant. Random samples from both cryoprecipitate and the two-component fibrin glue were free of hepatitis and retrovirus. CONCLUSIONS: The GRFG glue should be used as a tissue reinforcer; the two-component fibrin sealer is preferable when hemostatic action must be accompanied with mechanical barrier; and finally, the cryoprecipitate glue can be used when hemostatic action is the only requirement.

Animals↗
PubMed1994

The effects of nitric oxide inhibition on regional hemodynamics during hyperdynamic endotoxemia.

OBJECTIVE: To determine the effect of the inhibition of nitric oxide (NO) on selective organ blood flow in endotoxin-induced sepsis. DESIGN: Nonrandomized, controlled experiment. SETTING: Animal research facility in Brooklyn, NY. PARTICIPANTS: Eleven mongrel dogs. INTERVENTION: Eleven dogs were divided into one of two groups: a control group (n = 5) and an endotoxin-treated group (n = 6). The animals were anesthetized, and electromagnetic and ultrasonic flow probes were placed on the distal aorta, right internal carotid artery, superior mesenteric artery, and left renal artery. Sepsis was induced with a 60-mg/kg intravenous injection of Escherichia coli endotoxin. When the arterial blood pressure decreased to less than 60 mm Hg despite adequate fluid resuscitation, NO synthesis was inhibited with a 25-mg/kg intravenous administration of NG-monomethyl-L-arginine. After 15 minutes of inhibition, a 400-mg/kg intravenous administration of L-arginine, the substrate of NO synthase enzyme, was given. Physiologic measurements were continued for 15 minutes thereafter. MAIN OUTCOME MEASURES: Heart rate, blood pressure, central venous pressure, pulmonary artery pressure, pulmonary capillary wedge pressure, cardiac output, hematocrit, arterial and venous blood gas values, and blood flow measurements of right internal carotid artery, superior mesenteric artery, left renal artery, and distal aorta. RESULTS: Control animals did not demonstrate a significant (P > .05) decrease in blood flow in the internal carotid artery, superior mesenteric artery, and distal aorta after the administration of NG-monomethyl-L-arginine. The endotoxin-treated group showed a significant (P < .05) decrease in organ perfusion when treated with the NO synthase inhibitor, NG-monomethyl-L-arginine. CONCLUSIONS: Inhibition of NO production in the treatment of sepsis caused a significant decrease in blood flow to all vascular beds in vivo. The role, if any, of the inhibition of NO in the treatment of sepsis is questioned.

Amino Acid Oxidoreductases↗
PubMed1994

Nitric oxide inhibition in the treatment of the sepsis syndrome is detrimental to tissue oxygenation.

The manifestations of the septic syndrome are thought to be mediated by cytokines through their role in the production of nitric oxide (NO). It is hypothesized that the inhibition of NO production with an inhibitor such as NG-monomethyl-L-arginine (L-NMMA) may be beneficial in the treatment of septic shock. Sepsis was induced by the intravenous administration of Escherichia coli endotoxin (60 micrograms/kg) in six conditioned mongrel dogs (20-24 kg). Mean arterial pressure (MAP), heart rate (HR), central venous pressure (CVP), and pulmonary artery pressure (PAP) were continuously monitored. Cardiac output (CO), pulmonary capillary wedge pressure (PCWP), and arterial and mixed venous blood gases were obtained every 10 min. When the MAP decreased below 60 mm Hg, NO inhibitor L-NMMA was given by intravenous injection (25 mg/kg). Physiologic parameters were then measured at 2 and 5 min after L-NMMA injection. Subsequently, L-arginine (400 mg/kg), the substrate for the NO synthase enzyme, was administered and measurements were repeated at similar intervals. L-NMMA in septic canines produced a significant increase in MAP and SVR with a significant decrease in CO and tissue oxygenation (DO2 and VO2). These changes were reversed with the administration of L-arginine. There were no significant differences in the PCWP, CVP, PAP, or HR throughout the entire study. These results suggest that the inhibition of NO production by L-NMMA in a septic model produces elevated MAP and SVR at the expense of tissue oxygenation. Thus, its use, as a principal means of therapy for the septic syndrome, may not be appropriate because of detrimental effects on tissue oxygenation.

Animals↗
PubMed1994

Morphology and subsequent development in culture of bovine oocytes matured in vitro under various conditions of fertilization.

The objective of these experiments was to evaluate factors affecting in vitro fertilization of bovine oocytes matured in vitro, and their subsequent development to blastocysts. In Expts 1 and 2, sperm concentration, spermatozoa and oocyte incubation time, motility enhancers and semen source were manipulated. Fluorescent microscopy of microtubules and chromatin was used to observe sperm penetration rate, sperm aster formation and chromatin decondensation. Oocyte penetration rates were affected by sperm concentration but not by spermatozoa and oocyte incubation time. The effect of sperm concentration was due primarily to changes in polyspermy and not monospermy. Motility enhancers had no effect on any parameter measured. In Expt 3, oocytes were matured for 17, 22, 28 and 34 h before fertilization and evaluated for fertilization rates, morphology of cortical granules and exocytosis and blastocyst development. A domain free of cortical granules that was associated with the metaphase chromatin was not observed in mature bovine oocytes. As oocytes matured from 17 to 34 h, the distribution of cortical granules progressed from clustered to diffuse. Although monospermic fertilization rates were similar and cortical granule exocytosis occurred in all groups, polyspermy increased with maturation time. Development to blastocysts increased from 17 to 22 h of maturation but decreased thereafter with increasing maturation time. These results suggest that polyspermy can be reduced by adjusting sperm concentration and spermatozoa and oocyte incubation time with little effect on monospermic fertilization. Increased polyspermy with increased maturation time was not due to a lack of cortical granule exocytosis.

Animals↗
PubMed1993

Environmental scanning electron microscopy for dynamic corrosion studies of stainless steel piping used in UHP gas distribution systems.

An ElectroScan ESEM was used for in situ corrosion studies on cold drawn electropolished 316L stainless steel tube surfaces in the as-received and passivated conditions. Corrosion product was removed as it formed and the tube surface was viewed before, during, and after corrosive attack. The corrosion process was followed in situ, and the sample features most susceptible to corrosion (draw lines, inclusions, etc.) were identified. In addition, X-ray photoelectron spectroscopy (XPS) was used to study the changes in surface chemistry after corrosive attack. This information provided clear evidence of relevant corrosion mechanisms and relative corrosion susceptibility.

Corrosion↗
PubMed1992

Intrathecal perfusion of an oxygenated perfluorocarbon prevents paraplegia after aortic occlusion.

A canine model was used to evaluate the effects of continuous intrathecal perfusion of an oxygenated perfluorocarbon emulsion on systemic and cerebral hemodynamics and neurologic outcome after 70 minutes of normothermic aortic occlusion. Twelve mongrel dogs were instrumented to monitor proximal and distal arterial blood pressure, cerebrospinal fluid pressure, spinal cord perfusion pressure, and somatosensory evoked potentials. The intrathecal perfusion apparatus consisted of two perfusing catheters, placed in the intrathecal space through a laminectomy, and a draining catheter percutaneously inserted in the cisterna cerebellomedullaris. The aorta was cross-clamped just distal to the left subclavian artery for 70 minutes. Animals were randomized into two groups: group 1 (n = 6) animals were treated with intrathecal perfusion of saline solution, whereas group 2 (n = 6) animals received oxygenated Fluosol-DA 20%. Data were acquired at baseline, during the cross-clamp period, and after reperfusion. Normothermic Fluosol or saline solution was infused at a rate of 15 mL/min beginning 15 minutes before cross-clamping and continued throughout the ischemic interval. There was no difference in proximal arterial blood pressure (97.2 versus 95.4 mm Hg; p > 0.05) or distal arterial blood pressure (14.6 versus 15.0; p > 0.05) between the two groups throughout the cross-clamp interval. Cerebrospinal fluid pressure rose significantly in both groups with the onset of intrathecal perfusion of either saline solution or Fluosol (7 +/- 1 versus 24 +/- 5 and 8 +/- 1 versus 40 +/- 4 mm Hg, respectively; p < 0.05). The rise in cerebrospinal fluid pressure was sustained throughout the perfusion interval in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Determination of sorbic acid in margarine and butter by high-performance liquid chromatography with fluorescence detection.

A procedure is reported for the separation and determination of sorbic acid, as a derivative of 4-bromoethyl-6,7-dimethoxycoumarin, by reversed-phase high-performance liquid chromatography with fluorescence detection using enanthic acid as an internal standard. Sorbic acid, separated from samples of commercial margarine and butter by steam distillation, was evaluated using the proposed procedure and by UV absorption and visible spectrophotometric methods (AOAC). The preparation of the calibration graph and the determination of sorbic acid with the visible spectrophotometric method was improved. The sorbic acid content determined using UV and visible spectrophotometric methods was higher than that obtained with the reversed-phase performance liquid chromatographic method owing to the presence of interfering substances in the samples. The range of recovery and the precision of the proposed method and the reference methods are also reported.

Animals↗
PubMed1991

Hemodynamic and hemorheologic effects of i.v. Dilevalol in hypertensive patients.

The authors evaluated the effect of Dilevalol infusion on blood pressure, heart rate, central hemodynamics, and rheologic parameters in hospitalized inpatients affected with mild or moderate hypertension. After a dose-finding phase and a washout period of one week, 10 patients aged fifty to seventy-two-years (median 61.5) were given either a single dose of Dilevalol 60 mg or placebo, and seven days later they underwent the other treatment, according to a single-blind, crossover design. Central hemodynamic measurements were performed by means of M-mode echocardiography, and hemorheologic parameters were evaluated by means of strain-gauge plethysmography. The maximal increase in lower extremity flow at rest had been obtained with the infusion of 60 mg Dilevalol during dose-finding, and so this dose was chosen for the second part of the study. The infusion of Dilevalol significantly increased rest flow and decreased blood viscosity, but the changes in central, parameters were not considered clinically relevant, although statistically significant. Blood pressure decreased without significant changes in heart rate. Thus, the acute administration of Dilevalol reduced blood pressure, without affecting heart rate and central hemodynamics, confirming the vasodilating effect of the drug. A significant improvement was also shown on blood viscosity in these hypertensive patients.

Blood Viscosity↗
PubMed1991

Role of arachidonic acid metabolites in oleic acid induced pulmonary injury in a canine model. Effect of ketoconazole (thromboxane synthetase inhibitor).

This study was designed to investigate the effects of ketoconazole, a thromboxane synthetase inhibitor, on pulmonary and systemic hemodynamics and pulmonary function in experimental respiratory distress syndrome. Pulmonary artery infusion of oleic acid (PAIOA), 0.1 ml/kg, was used to cause lung injury. Ten dogs were randomized into two groups (Gps): Gp I (n = 5) acted as control, whereas Gp II (n = 5) were treated with IV ketoconazole (2.5 mg/kg bolus then 10 mg/kg/hour for 2.5 hours). Hemodynamics, extravascular lung water (EVLW), serum levels of PGE2, and TxB2 were obtained at baseline (BL) and at 30-minute intervals for 2.5 hours (T30-T150). After 30 minutes of PAIOA the mean arterial pressure (MAP) decreased significantly in both Gps (131 +/- 17 vs. 88 +/- 9 mmHg Gp 1, 119 +/- 9 vs. 79 +/- 8 mmHg Gp II, P less than 0.05); however, while MAP returned to BL values in Gp II, it remained significantly lower throughout the experimental interval in Gp I. Mean pulmonary artery pressure (MAP) was not significantly affected by PAIOA in either Gp, while pulmonary vascular resistance increased significantly from BL at T120 in Gp II. Pulmonary function measured by partial pressure of arterial O2 (PaO2) and extravascular lung water (EVLW) were significantly affected by PAIOA. There was a significant decrease in PaO2 (66 +/- 6 vs. 96 +/- 8 mmHg, Gp I and 60 +/- 7 vs. 100 +/- 6 mmHg, Gp II) as well as an increase in EVLW (604 +/- 61 vs. 135 +/- 9 ml, Gp I and 641 +/- 110 vs. 117 +/- 18 ml, Gp II) in both Gps.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[Calcium dobesilate in the treatment of primary venous insufficiency of the lower limbs. A controlled clinical study].

Fourty patients with lower limb chronic venous insufficiency entered a randomised placebo controlled study with calcium dobesilate for one month. Clinical symptoms and plethysmographic parameters were evaluated before and after therapy in all patients. In the group of patients treated with calcium dobesilate we observed an improvement of clinical and instrumental parameters; no changes were found in the placebo group. We observed good tolerance to the drug and no side effects required withdrawal of treatment.

Aged↗
PubMed1990

5'-nucleotidase from bull seminal plasma, chicken gizzard and snake venom is a zinc metalloprotein.

Using flame atomic absorption spectrometry the tight association of zinc to three different purified 5'-nucleotidases at a molar ratio of 2 could be proven. These 5'-nucleotidases purified from bull seminal plasma (BSP), chicken gizzard (CG) and snake venom (SV) are thus zinc metalloproteins. Removal of zinc results in the loss of their AMPase activity, which could be fully restored after readdition of zinc at a molar ratio of 2, for BSP and CG, and 1.5, for SV 5'-nucleotidase. Reactivation of their AMPase activity after the removal of zinc could also be obtained by addition of cobalt and copper ions, which were found to also bind with a molar ratio of 2 to the three 5'-nucleotidases tested.

5'-Nucleotidase↗
PubMed1989

In vivo and in vitro evidence of an adenosine-mediated mechanism of calcium entry blocker activities.

Drugs such as dipyridamole (200 micrograms/kg/min), an adenosine uptake inhibitor, and theophylline (300 micrograms/kg/min), an adenosine receptor antagonist, respectively increased and decreased postischemic hyperemia in normal subjects, as well as in POAD patients. Moreover, dipyridamole pretreatment was able to antagonize the reduction of peak flow induced by nifedipine, and the potentiating effect of flunarizine on postischemic hyperemia was affected significantly by theophylline, thus suggesting a possible interference of calcium entry blocker drugs with the endogenous adenosine system. In a cellular model (polymorphonuclear leukocytes--PMN) the inhibitory effect of calcium entry blockers on stimulated functions (degranulation and free radical production) was highly antagonized by theophylline. Finally, a 1H-NMR spectroscopy study showed a binding interaction between adenosine and flunarizine on the cell membrane. An adenosine-receptor coupling to the calcium entry blocker channels is suggested.

Adenosine↗
PubMed1988

Nutritional status of a group of institutionalized elderly people in Perugia (Italy).

In this group of institutionalized elderly people the anthropometry and body composition situation is much better than that observed in a noninstitutionalized group examined longitudinally on a previous occasion. On the other hand, as expected, indices of physical activity are lower. The diet is in general satisfactory, considering the very low physical activity of those individuals. Only a few foods and nutrients show marginal low intakes (fish, eggs and legumes; lipids, iron, thiamin and vitamin A).

Aged↗
PubMed1987

[Mortality and morbidity due to alcoholism].

The basic data used are statistics of causes of death, with correction taking into account unspecified causes of death. In a first part, we show different aspects of mortality due to alcoholism and cirrhosis of liver: variations recording sex and age group, time evolution, seasonal variations, regional variations. In a second part, we estimated, with a model, prevalence and incidence rates of these two causes of death, according sex and age group.

Adolescent↗