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Biomedical subjects

R Russo

Publications and source records attributed to R Russo.

At least 19 recordsLinked to original sources
PubMed1992

New modified heterocyclic phenylalanine derivatives. Incorporation into potent inhibitors of human renin.

Modified heterocyclic phenylalanine analogues designed as replacements for the P3-P4 region were synthesized and incorporated into renin inhibitors. These inhibitors were found to have significant activity versus human recombinant renin, as well as in vivo activity. The compounds proved to be very resistant to chymotrypsin degradation, as exemplified by compound 8, which remained greater than 60% intact after a 24-h exposure to chymotrypsin. In contrast, the Boc-Phe analogue was nearly completely degraded after 1 h. Compound 6 proved to be the most potent renin inhibitor with an IC50 = 8.9 nM. These stable cyclized phenylalanines should prove to be generally useful as a substitute for Boc-Phe in protease inhibitors.

Angiotensin I↗
PubMed1992

Diagnostic value of growth hormone-releasing hormone test in children and adolescents with idiopathic growth hormone deficiency.

Average growth hormone (GH) peaks following an i.v. growth hormone releasing hormone (GHRH) 1-29 stimulation test were significantly lower in 48 children and adolescents with GH deficiency (GHD) than in 20 age-matched controls (15.2 + 12.7 vs 37.5 + 28.1 ng/ml, 2 P less than 0.001). Twelve patients exhibited a low GH peak (less than 5 ng/ml), 27 demonstrated a normal response (greater than 10 ng/ml) and 9 showed an intermediate rise in plasma GH (5-10 ng/ml). Six of the 12 patients with low GH response to the first GHRH stimulation failed to respond to two other tests immediately before and after a 1 week priming with s.c. GHRH. These subjects with subnormal GH increase at repeat testing had total GHD (TGHD) and multiple pituitary hormone deficiency (MPHD) and had suffered from perinatal distress. On the contrary, 26 of 27 patients with normal GH response to the first test had isolated GHD and only a minority (8/27) had signs of perinatal distress. It is concluded that perinatal injuries primarily damage pituitary structures and that a pituitary defect more probably underlies more severe forms (TGHD and MPHD) of GHD.

Adolescent↗
PubMed1992

Growth hormone release during insulin tolerance, clonidine, arginine and growth hormone releasing hormone tests in short normal children and adolescents.

This study was retrospectively performed in 574 short normal children and adolescents [328 underwent insulin tolerance test (ITT), 34 clonidine test (CLON), 64 arginine test (ARG), 19 GHRH test, 52 ITT+CLON, 30 GHRH+CLON, and 47 ITT+CLON+GHRH) in order to evaluate the effect of pubertal stage on GH response to different tests and to identify the most likely mechanism of action of different stimuli. GH peak was higher during GHRH than in all other tests. Sex or start of pubertal development did not cause any GH peak difference. Low-responder (GH peak less than 10 ng/ml) percentages were similar (ITT = 13.5%, CLON = 13.4%, ARG = 13.2%, GHRH = 10.6%) also when the subjects were divided according to sex and pubertal development. ITT+CLON showed discordant results in 42/99 subjects (30/42 = 71.4% were low-responders to ITT and 12/42 = 28.6% to CLON). GH peak appeared earlier during GHRH (85% less than 45 min) and later during CLON (78%: 60-120 min) than during all other tests; GH peak during ITT showed a wide variability of time. Negative correlations were found between GH peak during GHRH and chronological age, height and bone age and during CLON and chronological age. In conclusion our data show that these tests have similar GH secretagogue reliability.

Adolescent↗
PubMed1992

Compulsory and non-compulsory immunizations: contraindications perceived by medical practitioners.

A total of 284 general practitioners (GPs), paediatricians and doctors of public vaccination centres (DPVC) were interviewed to investigate their willingness to immunize children with compulsory (diphtheria-tetanus, oral polio) and non-compulsory (measles, pertussis) vaccines in the presence of 19 different medical histories. We observed a reluctance to immunize in the case of false contraindications, a lack of information mainly about non-compulsory immunizations, and doubts about the real contraindications to polio, measles and pertussis vaccines. The frequency of correct answers to the question posed was significantly higher in the group with less than 20 years of experience, and the DPVCs proved better informed about immunization. However, the crucial role played by the GPs and paediatricians' advice can prejudice the correct use of active immunization.

Attitude of Health Personnel↗
PubMed1992

Stone surface area determination techniques: a unifying concept of staghorn stone burden assessment.

The use of stone surface area measurements obtained from standard radiographs provides a more accurate and reproducible assessment of stone burden when reporting results and treatment recommendations for staghorn calculi. Techniques for determining stone surface area include use of graph paper, planimeter or computerized image analysis. The use of graph paper is inefficient while planimeters suffer from significant variation for areas less than 500 mm.2 (more than 5%). Computer image analysis is accurate, rapid and easiest to perform. Software programs compatible with microcomputers are readily available making assessment of stone surface area practical and inexpensive. Stone surface area showed close correlation to stone volume as measured by 3-dimensional computerized tomography (correlation coefficient 0.84, p = 0.005). Stone surface area determination enables more accurate reporting of treatment results and, thus, recommendations based upon stone burden. Comparison of data between institutions becomes more meaningful if stone surface area is used. Stone surface area also provides a useful basis to study and compare trends of treatment within a single institution.

Humans↗
PubMed1992

[Immunogenicity of a recombinant vaccine against viral hepatitis B].

The introduction in Italy of recombinant DNA hepatitis B vaccines has allowed to plan out a very important programme of vaccination; in Italy the compulsory vaccination against hepatitis B virus begun from 1991. Because of the reduction of vaccine cost, the screening for serum markers of HBV infection is needless. On the contrary, the test of antiHBs titres after the vaccination is important in order to take into account a booster vaccine dose and to carry out revaccination strategies. In this study, we analyzed 419 subjects vaccinated with Engerix-B; the immune response was correlated with private and behaviour data.

Adult↗
PubMed1992

[Laparoscopic treatment of gastroesophageal reflux].

Authors describe laparoscopic treatment of gastroesophageal reflux disease in 12 patients. Particular aspects related to intra-operative complications are referred. Moreover the reasons that make laparoscopic procedure advantageous are discussed.

Adult↗
PubMed1992

Muscle protein turnover and amino acid metabolism in patients with chronic renal failure.

Muscle protein turnover and amino acid (AA) exchange were studied in 4 patients with chronic renal failure (CRF) and in 5 controls in the postabsorptive state by using the forearm perfusion method together with the systemic infusion of 3H-Phe. In CRF patients muscle protein breakdown is increased and is associated with a parallel increase in protein synthesis. Protein breakdown is inversely related to arterial bicarbonate. Net proteolysis is unchanged. The release of total AA, glutamine and alanine is not different from controls, whereas the release of valine and leucine is reduced and serine uptake tends to be decreased. In conclusion, in postabsorptive patients with CRF, well before the uremic stage, an increased protein breakdown associated with metabolic acidosis takes place; net proteolysis is unaffected. Alterations in BCAA metabolism suggest the occurrence of increased BCAA degradation proceeding beyond the transamination step.

Adult↗
PubMed1992

[Rare metastases].

The paper reports a number of cases of uncommon metastasis confirmed by histological tests in surgical biopsies; following a brief discussion of the literature on this topic and in particular on the basis of an earlier study by one of the authors, the paper affirms that metastasis is related to general and local biological factors, that the diffusion of neoplastic cells is an early and generalised phenomenon opposed by organic defence mechanisms, and that the concept of uncommon metastasis should be revised, without resorting to fixed anatomical references, according to a general "impregnation" of tumour cells.

Breast Neoplasms↗
PubMed1992

[Pulmonary tuberculosis and other mycobacterial infections in patients with AIDS].

Nowadays, the acquired immune deficiency syndrome (AIDS) is most certainly the major cause of the increased incidence of tuberculosis (TBC). A total of 138 patients (pts) with AIDS were referred to the Department of Infectious Diseases of the Hospital of Pisa, 1990-1991; 14 of them (10.1%) presented pulmonary TBC. In our study, we analyzed the chest films of the latter group of patients. Based on the X-ray patterns, the findings were classified as follows: hilar lymph nodes were observed in 4 pts (28.6%), isolated lymph nodes in 2 cases; associated with parenchymal involvement in 2 pts; acute alveolar TBC was seen in 4 cases (28.6%), with escavations in 3/4 (21.4%). Linear and reticular TBC were found in 4 pts (28.6%), and miliary interstitial involvement in 1 case (7%), extrapulmonary adenopathy in 4 pts (28.6%). In 4 pts (28.6%) chest X-ray findings were negative. All pts underwent serial chest X-rays in the course of therapy. HRCT was performed in 6 patients: our results are in agreement with those reported in literature. Thus, we can conclude that the major diagnostic findings in our series were: frequent isolated involvement of hilar lymph nodes, as observed in primary TBC; the infiltrates are most frequently located in the middle and basal lobes; escavations are uncommon; pleural effusion is unusual; in some pts chest X-ray findings may be negative.

Acquired Immunodeficiency Syndrome↗
PubMed1992

[Microcirculatory changes in mitral prolapse as an expression of a systemic change in the connective tissue].

Many authors hypothesize that mitral valve prolapse (MVP) can be, in most cases, only a clinical sign of a primitive and systemic disorder of the connective tissue, like in Marfan Syndrome (MS). In our previous works we supported the presence of morphological and functional alterations of the microcirculation in patients affected by MS. In order to characterize a possible common denominator between these pathologies we have studied the cutaneous microcirculation in a group of patients affected by MVP, divided into 2 groups: anatomic MVP (MVP) and MVP syndrome (MVPS). The morphologic parameters have been investigated by nailfold capillaroscopy while digital laser-Doppler was used to study skin flowmetry. The results have been compared with a control group. Capillaroscopic remarkers showed an architecturally disorganized microvasculature with aspects related to a reduced compactness of the microvasculature unit with a significatively higher score compared with controls (7.3 +/- 2.9 vs 3.6 +/- 1 p less than 0.0005). Laser-Doppler flowmetry showed a significatively reduced rest flow; ischemic test showed: spike time 48.9 +/- 36.9 vs 15.3 +/- 7.7 s (p less than 0.0005), hyperemic acme 6.6 +/- 2.7 vs 12.5 +/- 8.4 UP (p less than 0.002); % increase 32.1 +/- 20.2 vs 51.5 +/- 15.4 (p less than 0.002). Thermic test showed a significatively higher thermic acme 8.7 +/- 4.2 vs 12.6 +/- 9.11 UP (p less than 0.05). These results appeared to be correlated with stage pathology as it was observed a severe microvasculature disorders in MVPS. Therefore we suppose that a phenotypic continuum may exist between MS and MVP.

Adult↗
PubMed1992

[Cardiac involvement in pheochromocytoma. A report of 6 cases].

Pheochromocytoma is a rare case of sustained hypertension or hypertensive crisis: sometimes it may occur with several aspecific symptoms or hypotension. The literature reports frequent myocardial involvement in patients affected by pheochromocytoma. Adrenergic hormone effects are responsible for a functional coronary insufficiency which causes myocardial damage. The cardiac involvement may appear with symptoms of different severity that sometimes represent the only symptoms of the neoplasia. Clinical and instrumental cardiac alterations observed in 6 patients suffering from pheochromocytoma are reported. Electrocardiographic abnormalities were found in 5 out of 6 patients. Inferior myocardial infarct was present in one case; in two patients electrocardiogram showed left ventricular hypertrophy and negative T wave; frequent ventricular extrasystoles in one case and complete atrio-ventricular block in another were found during the hypertensive crisis; in one patient the electrocardiogram showed STT changes and in the last one, left ventricular hypertrophy, more evident in the interventricular septum, was present at the echocardiogram. All subjects underwent surgical treatment after a period of drug therapy. To date surgery is the only possibility to eliminate myocardial malignant effects of catecholamines.

Acute Disease↗
PubMed1991

Reversed-phase high-performance liquid chromatographic analysis of branched-chain keto acid hydrazone derivatives: optimization of techniques and application to branched-chain keto acid balance studies across the forearm.

A sensitive method of quantifying branched-chain keto acids in plasma and whole blood samples is described. It is based on the separation by ion-pair reversed-phase liquid chromatography of 2,4-dinitrophenylhydrazine derivatives with ultraviolet detection. The sample clean-up steps that are usually required for reversed-phase high-performance liquid chromatography are eliminated. A reduction in ketoisocaproate isomer formation is obtained by incubation of derivatives in ice. The method is reproducible (coefficient of variation 2%, n = 5, at the 200-pmol level) and the ultraviolet response is linearly related to branched-chain keto acid concentration. Recoveries are high (greater than 95%). Other keto acids do not co-elute with branched-chain keto acids. Because of its sensitivity and precision, this method can be proposed for whole blood branched-chain keto acid balance studies across organs.

Biological Transport↗