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Biomedical subjects

A Rizzo

Publications and source records attributed to A Rizzo.

At least 109 records · Page 6Linked to original sources
PubMed1989

Free fatty acids and lipid peroxidation in normal and mastitic bovine milk.

Milk levels of free fatty acids (FFA) and prostaglandins (PGs) were determined in healthy cows and in those with mastitis and compared with some parameters commonly used for diagnosing mastitis. A modified gas chromatography-mass spectrometry method was used. In mastitis there was a substantial overall increase in FFA levels in milk. Specific attention was paid to the fate of the long-chain polyunsaturated fatty acids, known as precursors for the production of PGs, leukotrienes and other eicosanoids. Both the omega-6 and omega-3 lines of these lipids were increased in mastitis, but only in proportion to other FFA. The milk levels of PGs (PGF2, PGF2 alpha, thromboxane B2) were elevated in the same proportion. The possible importance of lipid peroxidation, inflammatory reaction and host defence are evaluated in relation to tissue destruction and oxidative killing of pathogens. It may be possible to manipulate the intake and fate of FFA in the organism by dietary intake, antioxidants and proper storing of feed. It is concluded that in studies concerning FFA special attention should be given to those long-chain fatty acids that are precursors for the formation of eicosanoids.

Animals↗
PubMed1989

Role of plasma fatty acids, prostaglandins and antioxidant balance in bovine mastitis.

Plasma levels of free fatty acids (FFA) were measured in cows with mastitis. FFA levels are known to be elevated in milk of affected cows, and similar increases were now observed in blood plasma. Of the long-chain polyunsaturated fatty acids which serve as precursors for prostaglandins (PGs), leukotrienes (LT) and related eicosanoids, arachidonic acid (C20: 4 omega-6) was elevated by 156 per cent and C20: 3 (consisting of both omega-3 and omega-6) 153 per cent; eicosapentaenoic acid (20: 5 omega-3), not present in the plasma of healthy animals, was detected in blood of mastitic animals. Arachidonic acid correlated positively with the plasma levels of PGs. Total plasma phospholipids were increased as well, and they were positively correlated with the levels of linoleic and arachidonic acids. Changes in FFA levels correlated positively with parameters of inflammation, like bovine serum albumin and serum N-acetyl-beta-D-glucosaminidase, but negatively with the antioxidant status of the animals (vitamin E, glutathione peroxidase). As PGs and LTs are mediators of inflammation, and products of lipid peroxidation, the increase of plasma FFA could be related to tissue damage caused by oxygen free radicals. Similar processes are, however, involved also in host defence, e.g. in oxidative killing of pathogens.

Acetylglucosaminidase↗
PubMed1989

Investigation on trichothecene-stimulated lipid peroxidation and toxic effects of trichothecenes in animals.

Three experiments were performed with mice intoxicated with trichothecene-contamined feed or directly into the stomach. Lipid peroxidation was estimated by the TBA value from liver samples, but since such a test seldom provided reliable results, lipid hydroperoxides and total carbonyl were also analyzed. The formation of aldehydes and ketones was compared in vivo and in vitro. The same investigations were conducted on chickens, rainbow trouts and numerous fur animals suspected of chronic intoxication by trichothecenes. The vitamin A concentration was used as a parameter to detect alterations caused in chickens by trichothecenes. Our investigation provided evidence that lipid peroxidation is associated with trichothecene poisoning. The T-2 toxin, even in small concentrations, seems to induce strong lipid peroxidation. When DON and 3-AcDON were given together at a dosage of 180 micrograms/kg feed, 1 week's feeding caused clear lipid peroxidation in mice. Particular attention should be paid to the fact that mycotoxins may already be present in the feed before any experiment is conducted.

Animals↗
PubMed1988

Computed tomography of abdominal aortic aneurysm. An in vivo pathological report with a note on dynamic predictors.

A group of computed tomography (CT) descriptors were derived for abdominal aortic aneurysms. Terminology was defined and applied to the interpretation of the CT image in 55 prospective cases. Correlation of geometric parameters of aneurysm and analysis of the relationship of internal aneurysm components such as lumen and thrombus was performed. Predictive growth patterns for aneurysm demonstrated a synchronous increase in the volume of thrombus within the aneurysm in those aneurysms measuring 5 to 7 cm. Aneurysms greater than 7 cm were associated with an expansion of the patent pulsatile lumen, with no appreciable increase in thrombus volume. The thrombus-lumen ratio effectively described the changing internal architecture of aneurysm associated with increase in size. Proper utilization of CT descriptors develops a language that interprets aneurysm stability and potential for rupture and may provide an improved basis for timely surgical planning.

Aged↗
PubMed1988

Effect of body weight on the volume of distribution of theophylline.

The volume of distribution (Vd) of theophylline and the relevant aminophylline loading dose (LD) are usually calculated on the basis of total body weight (TBW). In obese subjects it has been suggested that lean or ideal body weight (IBW) is the best predictor. In a sample of 40 acutely ill asthmatic patients (aged 22 to 78 yr, weighing 45 to 176 kg) we measured Vd and found that (1) it increases with TBW, (2) it cannot be accurately predicted from either TBW or IBW alone by a simple regression analysis. Power functions have been usefully applied in comparing the pharmacokinetics of animal species, including humans, with different body mass. In our sample, data were best fitted by the equation Vd = 1.29 TBW 0.74, which seems to take care of lean as well as obese patients. Results were confirmed (r = 0.89 between predicted and measured values) in a second independent sample of patients (aged 26 to 77 yr, weighing 38 to 167 kg). This helps to minimize the error in obtaining the target serum concentration of theophylline when giving a LD calculated from a predicted Vd value.

Adult↗
PubMed1988

WR-2721 entry into the brain across a modified blood-brain barrier.

Radioprotection of the CNS by WR-2721 has not been possible because of its inability to cross the blood-brain barrier (BBB) and so gain access to the neural tissue. Modification of the BBB using hypertonic arabinose (1.8 m), injected via the internal carotid artery (ica), permitted entry of ip-injected [14C]WR-2721 into the ipsilateral cerebral hemisphere. The BBB-modified hemisphere had a 5.34-fold increased uptake compared to nonmodified controls. Delivery as a bolus via the ica further enhanced uptake after BBB opening; WR-2721 was 3.73 times greater than by ip injection. A 20-fold increase of WR-2721 brain uptake has been calculated for ica administration with the BBB opened as compared to the ip route without BBB modification. Toxicity of ip-administered WR-2721 with the BBB open was only 1.4 times greater than non-modified controls and 1.96 times more toxic when delivered via the ica. These data demonstrate significant uptake of WR-2721 into the CNS, a previously unprotected organ, and provide a model for future radioprotective studies.

Amifostine↗
PubMed1988

Anti HSV-2 properties of amniotic fluid.

Some antiviral properties of amniotic fluid (AF) were studied. A close relationship between maternal blood and AF antiviral antibodies was seen. Substances other than antibodies which could have an effect on viruses were assumed to be present in AF. Using HSV2 as a model, we found a virus-neutralizing activity in 6 out of 7 specimens studied which does not appear to be related to antibodies.

Adult↗
PubMed1988

Role of Broviac catheters in infections in children with cancer.

In a 3-year period 157 single lumen Broviac catheters were inserted in 145 children with various neoplastic diseases. The overall duration of the catheter courses was 30,533 days (median, 171; range, 2 to 647). Sixty-five percent of the catheter courses (102 of 157) were complicated by at least 1 febrile episode, for a total of 157 episodes. According to European Organization for Research on Treatment of Cancer criteria, 79 febrile episodes (50%) were classified as microbiologically documented infections, 57 (36%) with and 22 (14%) without septicemia; 31 (20%) as clinically documented infections; and 47 (30%) as possible infections. Of the 79 microbiologically documented infections 21 were catheter-related infections (CRI), 32 were catheter-unrelated infections and 26 were infections of unknown source. Only 48% of CRI occurred during neutropenia (less than 1000 neutrophils/mm3), compared with 88% of catheter-unrelated infections and 96% of infections of unknown origin (P = 0.00007). Gram-positive microorganisms (56% staphylococci) accounted for 78% of all isolates in CRI, 47% in catheter-unrelated infections and 43% in infections of unknown origins (P = 0.03). Fungi represented 12% of all isolates. Clinical and microbiologic resolution without removal of the catheter was achieved in 12 of 21 CRI (57%) and no patient died from a CRI. This study indicates that over 3 of 4 of CRI are caused by Gram-positive bacteria, occur in neutropenic and non-neutropenic patients (approximately 50%) and can be successfully treated without removing the catheter.

Adolescent↗
PubMed1987

Lower extremity swelling: computerized tomography following negative venography.

In 21 patients who had lower extremity swelling and negative venography, radiographic evaluation was extended to include computerized tomography (CT) of the lower extremity, which we have termed venography-CT, or VCT. All patients were referred with the diagnosis of deep vein thrombosis (DVT) and no patient had a history of trauma. CT was effective in demonstrating two occult mechanisms of lower extremity swelling: knee joint effusion (three patients) and intramuscular hemorrhage (five patients). Selective utilization of CT in the evaluation of lower extremity swelling is effective in directing the clinical management of these patients.

Adult↗
PubMed1987

Low-dose tranexamic acid combined with aprotinin in the pre-operative management of ruptured intracranial aneurysms.

Among our patients with ruptured intracranial aneurysms 149 were managed pre-operatively with a combination of tranexamic acid (AMCA), 3 gm daily, and aprotinin at an average of 400,000 KIU (Kallikrein inactivating units) daily. Antifibrinolytics were started within three days of the last haemorrhage, and continued for at least six days. The first 91 cases, managed in the years 1971 to 1980, have been evaluated retrospectively. The remaining 58 patients were managed in the period 1981-1985 and carefully watched for possible complications of treatment. No significant differences were noted in the results of patients managed either before or after 1981. The rate of recurrent SAH (10%) was lower than the natural history of aneurysmal SAH. Satisfactory inhibition of fibrinolysis was documented in the CSF collected at the time of operation in 15 patients. This, as well as our previous suggestions that the combination of low-dose AMCA and aprotinin might carry a lesser risk of causing ischaemic complications and hydrocephalus than the conventional antifibrinolytic treatment, might stimulate future studies on fibrinolysis in SAH.

Adult↗
PubMed1987

Effects of captopril on the physical work capacity of normotensive patients with stable-effort angina pectoris.

Twelve normotensive patients with coronary artery disease and stable effort-induced angina pectoris were selected: the antiischemic effect of captopril was studied. A maximal cycloergometer effort test was obtained before (base) and after administration of placebo or captopril (50 mg p.o.). The following parameters were measured: heart rate (HR), blood pressure (BP), maximal rate/pressure product (MRPP), maximal workload sustained, (MWS), maximal working time (MWT), and S-T depression at MRPP. The base and placebo were similar. Compared to them captopril augmented the MWT, increased the MWS, reduced S-T depression at MRPP, and decreased the number of patients with effort-induced angina pectoris. The antiischemic effect of captopril seems related both to its effect on HR and BP, and to a local enhancement of coronary blood flow.

Angina Pectoris↗