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Biomedical subjects

M Rubino

Publications and source records attributed to M Rubino.

At least 37 records · Page 2Linked to original sources
PubMed1999

Straddling tricuspid valve as a sign of ventriculoatrial malalignment: A morphometric study of 19 postmortem cases.

BACKGROUND: Straddling tricuspid valve, despite extensive investigation, remains an incompletely understood form of complex congenital heart disease. METHODS: A morphometric study of 19 postmortem cases of straddling tricuspid valve was performed, and the results were compared with 32 normal control heart specimens. RESULTS: In straddling tricuspid valve, marked malalignment of the ventricles was always found relative to the atria. The angle between the ventricular septum and the atrial septum in the short-axis projection averaged 61 degrees +/- 24 degrees, the normal ventriculoatrial septal angle averaging 5 degrees +/- 2 degrees (P <. 001). The right ventricular sinus (inflow tract) was significantly smaller than the left (P <.01). A ventricular septal defect was present in 79%: atrioventricular canal type in 42%, atrioventricular canal type confluent with a conoventricular defect in 26%, and a conoventricular defect in 11%. When the straddling tricuspid valve adhered to the crest of the muscular ventricular septum (n = 4 cases, 21%), the 2 salient findings were (1) an intact ventricular septum and (2) double-outlet right atrium. The nonstraddling part of the tricuspid valve opened into the small right ventricle. The straddling part of the tricuspid valve opened into the larger left ventricle. The mitral valve also opened into the left ventricle. Hence hearts with double-outlet right atrium had 3 atrioventricular valves. Congenital mitral stenosis was present in 26% of this series. CONCLUSION: Straddling tricuspid valve was always characterized by marked ventriculoatrial malalignment, indicated by an abnormally large ventriculoatrial septal angle, best seen in the short-axis projection.

Cadaver↗
PubMed1999

Naturally-occurring anti-Jka in infant twins.

Anti-Jka was detected by solid-phase red cell adherence (SPRCA) antibody detection and identification tests in the plasma of a 9-month-old female infant during a routine presurgical evaluation. The patient and her nonidentical twin sister, who also had anti-Jka in her plasma, were products of an uncomplicated in vitro fertilization, full-term pregnancy, and vaginal delivery. Neither twin had been transfused, recently infected, or treated with medication. Their mother had no prior pregnancies or transfusions. Red blood cells (RBCs) from the patient and her sister typed as Jk(a-b+) by direct hemagglutination, and this phenotype was confirmed by negative adsorption and elution studies. Both infants' plasma samples were strongly reactive with 20 examples of Jk(a+) RBCs and nonreactive with 20 examples of Jk(a-) RBCs by SPRCA assays. Anti-Jka was not detected in either twins' plasma by indirect antiglobulin tests by tube method in low-ionic- strength saline solution or polyethylene glycol, or with ficin- or papain-treated RBCs. Monocyte monolayer assays using Jk(a+) RBCs sensitized by either twins' serum were nonreactive (0%). RBCs from both parents typed as Jk(a+b+). Both parents' antibody detection test results by SPRCA assay were negative. The absence of a history of exposure to allogeneic RBCs or possible passive transfer of maternal or other alloantibody classifies these antibodies as naturally-occurring anti-Jka.

Journal Article↗
PubMed1997

A novel Rab5 GDP/GTP exchange factor complexed to Rabaptin-5 links nucleotide exchange to effector recruitment and function.

The small GTPase Rab5 plays an essential role in endocytic traffic. Rab GDP dissociation inhibitor delivers Rab5 to the membrane, where a nucleotide exchange activity allows recruitment of an effector protein, Rabaptin-5. Here we uncovered a novel 60 kDa Rab5-binding protein, Rabex-5. Rabex-5 forms a tight physical complex with Rabaptin-5, and this complex is essential for endocytic membrane fusion. Sequencing of mammalian Rabex-5 by nanoelectrospray mass spectrometry and cloning revealed striking homology to Vps9p, a yeast protein implicated in endocytic traffic. Rabex-5 displays GDP/GTP exchange activity on Rab5 upon delivery of the GTPase to the membrane. This demonstrates that a soluble exchange factor coupled to a Rab effector translocates from cytosol to the membrane, where the complex stabilizes the GTPase in the active state.

Animals↗
PubMed1997

Evaluation of the presence of 2-LTR HIV-1 unintegrated DNA as a simple molecular predictor of disease progression.

In a preliminary cross-sectional analysis of 109 human immunodeficiency virus type 1 (HIV-1)-infected subjects the presence of 2-long terminal repeat (LTR) unintegrated circular HIV-1 DNA in peripheral blood mononuclear cells (PBMC) was found to be associated with both symptomatic infection (P = 0.0037) and low CD4 counts (P = 0.0004). To investigate the prognostic significance of the presence of 2-LTR HIV-1 DNA, a subset of 23 2-LTR-negative and 25 2-LTR-positive asymptomatic individuals were followed up for 12-24 months. The two groups did not differ in terms of baseline CD4 counts, zidovudine (ZDV) therapy, and duration of HIV-1 infection. Longitudinal analysis of CD4 values did not indicate a significantly different CD4 outcome between the two groups. However, when only ZDV-treated subjects were considered, a significant (P = 0.042) decrease in CD4 counts was found at month 24 with respect to baseline in 2-LTR-positive (n = 12) but not in 2-LTR-negative (n = 11) patients. Moreover, when > 40% CD4 loss from baseline and/or development of CDC stage B or C symptoms were considered as indicators of disease progression, there was a significantly higher number of events in the whole 2-LTR-positive group than in the whole 2-LTR-negative group (P = 0.0197 at month 12, P = 0.0299 at month 18, P = 0.0373 at month 24). Thus, the presence of 2-LTR HIV-1 DNA in PBMC merits further investigation as a simple, qualitative, molecular predictor of disease progression and decreased response to antiretroviral therapy.

Cross-Sectional Studies↗
PubMed1997

Echocardiographic evaluation of systolic and diastolic left ventricular function following arterial switch operation in the neonatal period for transposition of the great arteries. Midterm results.

BACKGROUND: Neonatal arterial one-stage switch operation (ASO) for transposition of the great arteries (TGA) is currently the procedure of choice for TGA. There is a potential risk of myocardial damage related to coronary artery reimplantation and sudden pressure overload imposed on the left ventricle after discontinuation of the cardiopulmonary bypass. OBJECTIVES: This study was carried out in order to evaluate left ventricular systolic and diastolic function in children following ASO. METHODS: We studied 32 children (22 M, 10 F), mean age 23.7 +/- 24.6 months (range 0.5-97.2) following ASO, without any hemodynamically significant residual stenosis by 2D- and Doppler-echocardiography. Twenty-five had TGA with intact ventricular septum and 7 with ventricular septal defect. Mean age at time of one-stage repair was 8.9 +/- 6.9 days (range 2-30) and the mean time of follow-up 23.5 +/- 24.6 months (range 0.3-96). At the time of evaluation all the children were asymptomatic. Regional wall motion of the left ventricle was assessed by 2D-echo. Volumes, mass index, M/V ratio, afterload, systolic function (FS% and VCFc), contractility (stress-velocity SVI and stress-shortening SSI relations) and preload (functional preload index FPI = SSI-SVI) of the left ventricle were determined by m-mode echo together with non-invasive blood pressure monitoring. Left ventricular diastolic function was determined by PW Doppler of transmitral flow. All parameters were compared with those of 32 normal controls matched for age, sex and body surface area. RESULTS: Left ventricular regional wall motion was normal in all but 5 cases who showed a slight reduction of the septal systolic motion. Volumes and EF% did not differ in post-ASO group vs controls. There was a small increase of the mass index in the post-ASO group vs controls (62.8 +/- 14.1 vs 56.2 +/- 6.5 g/m2; p = 0.02) and the M/V ratio did not differ. FS% and VCFc were not different between the 2 groups. Peak and end-systolic meridional stress also did not differ in the 2 groups. A normal contractile state was present in the post-ASO group. The preload was slightly reduced in the post-ASO children (FPI -0.6 +/- 0.94 vs 0.07 +/- 0.63; p = 0.001). Parameters of left ventricular diastolic function were not significantly different between the 2 groups. CONCLUSIONS: In conclusion in children undergoing neonatal ASO for TGA with intact septum or ventricular septal defect, evaluated after a mean post-surgical follow-up of 2 years, systolic and diastolic performance of the left ventricle was normal. Regional wall motion abnormalities with slightly reduced septal motion were detected in 5 cases. The reason for the small increase in mass index is unknown. The slight reduction of the preload is related to the routine drug therapy in the patients studied early after surgical repair.

Child, Preschool↗
PubMed1996

Endosome dynamics regulated by a Rho protein.

Vesicular transport is a dynamic process that requires coordinated interactions between membrane and cytoskeleton. The mechanisms and molecules integrating these interactions are unclear. A Rho protein, RhoD, might provide a molecular link between membrane traffic and the cytoskeleton. Activated RhoD causes rearrangements of the actin cytoskeleton and cell surface, and governs early endosome motility and distribution.

Actins↗
PubMed1996

GTPase activity of Rab5 acts as a timer for endocytic membrane fusion.

The GTPase cycle is a versatile regulatory mechanism directing many cell functions, and Rab family members use it to regulate intracellular transport. Current models propose that GTP hydrolysis by Rab proteins is either required for membrane fusion or occurs afterwards to allow recycling of the protein. To measure the GTPase activity of Rab5 in endocytic membrane fusion, we engineered a mutant that preferentially binds xanthosine 5'-triphosphate (XTP),Rab5(D136N) and monitored the kinetics of [alpha(32)P]-XTP hydrolysis in situ during endosome fusion in vitro. Surprisingly, nucleotide hydrolysis occurred even in the absence of membrane fusion, indicating that membrane-bound Rab5 undergoes futile cycles of GTP(XTP) binding and hydrolysis. Nucleotide triphosphate hydrolysis by Rab5 is not conditional on membrane fusion and is reduced by its effector Rabaptin-5. Our data reveal that the GTP cycle of Rab proteins differs from that of other GTPases (for example, EF-Tu) and indicate that GTP hydrolysis acts as a timer that determines the frequency of membrane docking/fusion events.

ADP-Ribosylation Factors↗
PubMed1995

Concordance between polymerase chain reaction and antibody detection in the diagnosis of human immunodeficiency virus type 1 infection.

A highly sensitive nested polymerase chain reaction (PCR) protocol was used to detect human immunodeficiency virus type 1 (HIV-1) DNA in peripheral blood mononuclear cells from 271 HIV-1-seropositive patients, 240 HIV-1-seronegative subjects at increased risk for HIV-1 infection, 51 serologically indeterminate individuals, and 120 healthy blood donors. PCR was carried out in a multiplex nested configuration with pol and env region primer sets. HIV-1 DNA was detected in all of the HIV-1 seropositive patients. In contrast, HIV-1 DNA was not detected in any of the either seronegative or serologically indeterminate subjects. Only one of 37 seronegative regular sexual partners of HIV-1-infected patients who were followed longitudinally was found to seroconvert to HIV-1. However, HIV-1 DNA and antibody results were concordant in the four samples obtained from this subject prior to and after seroconversion. These results show an excellent concordance between HIV-1 DNA and antibody detection for diagnosis of HIV-1 infection and suggest that long-term HIV-1 infection in the absence of detectable antibody is likely to occur at a very low frequency.

Blotting, Western↗
PubMed1995

Repair of tetralogy of Fallot in the first six months of life: transatrial versus transventricular approach.

BACKGROUND: This report describes our experience with primary correction of tetralogy of Fallot in infants. METHODS: Fifty-one consecutive infants younger than 6 months underwent primary correction of tetralogy of Fallot between January 1978 and October 1994. Mean age at repair was 4.2 months. Four were neonates. Correction was accomplished through a right ventriculotomy in the first consecutive 22 patients (43%; group A); since 1991, a combined transatrial-transpulmonary approach was used in 29 consecutive patients (57%; group B). A transannular patch was necessary in 33 infants (65%) 16 of group A (73%) and 17 of group B (59%). RESULTS: There was one early death from possible left anterior descending coronary artery distortion in group A and no deaths in group B. Two patients required early reoperation for systemic-to-pulmonary artery collateral ligation (postoperative day 6) and permanent pacemaker implantation (postoperative day 30). There were no late deaths. All 50 survivors are currently asymptomatic and in New York Heart Association class I. Three patients required late reoperations 36 months, 30 months, and 13 months after repair for (1) subaortic stenosis and dysfunctioning dysplastic mitral valve, (2) residual pulmonary artery branch stenosis, and (3) residual right ventricular outflow obstruction. Four patients underwent balloon dilation and stent insertion (1 patient) for peripheral pulmonary artery stenosis 1.5 year to 12 years (mean, 5 years) after initial repair. Actuarial freedom from need for reintervention at 4 years was 78.4% in group A and 85.7% in group B. Two-dimensional and Doppler echocardiographic follow-up studies showed a residual mild to moderate pulmonary artery branch stenosis in 4 patients in group A, and a recurrent subaortic stenosis in 1 patient in group A. Right ventricular peak systolic pressure was less than 40 mm hg in all but 3 asymptomatic patients who had a residual pulmonary artery branch stenosis. Right ventricular end-systolic and end-diastolic volumes showed larger volumes and reduced ejection fraction in group A compared with group B. CONCLUSIONS: This limited experience with repair of tetralogy of Fallot in patients less than 6 months of age demonstrates that the transatrial-transventricular approach is possible in neonates and young infants with a very low mortality and morbidity and also a low incidence of residual lesions. Follow-up echocardiographic data suggest that right ventricular function is better preserved in those patients who underwent the transatrial-transpulmonary repair.

Cardiac Surgical Procedures↗
PubMed1995

Left atrioventricular valve incompetence after repair of common atrioventricular canal defects.

BACKGROUND: Reoperation rate for residual atrioventricular (AV) valve regurgitation after repair of common atrioventricular canal defect (AVCD) is currently between 5% and 10%. This retrospective analysis evaluates the impact of AV valve anatomy, age at repair, and surgical technique on postoperative AV valve incompetence. METHODS: Between January 1982 and July 1994, 205 patients with common AVCD underwent surgical repair at our institution. A complete form with common atrioventricular orifice (CCAVCD) was present in 81 patients. One hundred twenty-four had separate AV valves and orifices; 22 of these had a restrictive ventricular septal defect component. Preoperative moderate to severe AV valve regurgitation (AVVR) was present in 74 (36%), with a lower incidence in the CCAVCD group (20/81, 25%) versus the transitional (8/22, 36%) or the partial forms (46/102, 45%) (p = 0.02). The incidence was 12.5% (3/24) for CCAVCD patients less than 4 months of age (p = 0.02). Repair of the left AV valve was performed according to the trifoliate approach in most cases (142/205, 70%). Follow-up was 98% complete. RESULTS: By Kaplan-Meier analysis, survival at 12.3 years was 97.8% +/- 1% in partial AVCD, 95.4% +/- 4% in transitional AVCD, and 73.2% +/- 5% in CCAVCD (median follow-up, 60 months). Freedom from reoperation at 12.3 years was 93.5% +/- 2% for partial AVCD, 76.9 +/- 9% for the transitional form, and 68.3% +/- 5% for CCAVCD: Postoperative moderate to severe AVVR occurred in 42 patients (21%), with lower incidence for CCAVCD (10/81, 12.5%) versus transitional AVCD (8/22, 36%) and partial AVCD (24/102, 24%) (p = 0.02). Postoperative moderate AVVR was found in only 1 patient with CCAVCD less than 4 months of age (p < 0.01). Nine patients (5%) underwent reoperation for residual postoperative AVVR Valve repair was performed in all with no operative death. By Cox proportional risk multivariate analysis, preoperative AVVR and double orifice "mitral" valve were associated with increased risk of postoperative left AVVR (p < 0.01), whereas a bifoliate approach appeared to reduce the risk of this event in partial AVCD (p = 0.03). CONCLUSIONS: Postoperative AVVR is related to the type of anatomy of the AV valve, to the age at repair, and to the surgical technique employed. Residual AVVR can still be corrected with conservative techniques at low mortality rates. Early repair of common AVCD is associated with a lower incidence of preoperative and postoperative AVVR in CCAVCD and seems to prevent progression of annular dilation and preoperative AVVR in partial AVCD.

Aortic Valve Insufficiency↗
PubMed1995

Systemic and pulmonary venous connections in visceral heterotaxy with asplenia. Diagnostic and surgical considerations based on seventy-two autopsied cases.

To facilitate the preoperative diagnosis and surgical management of visceral heterotaxy and asplenia, 72 postmortem cases were reviewed with particular attention focused on the systemic and pulmonary venous connections. The superior vena cava was bilateral in 51 cases (71%), but in 9 cases one of the superior venae cavae was partly or totally atretic. Patent bilateral superior venae cavae were found in 42 cases (58%) and the superior vena cava was unilateral in 21 (29%). Although the inferior vena cava was never interrupted, a prominent azygos vein was found in 6 cases (8%). Some hepatic veins drained separately from the inferior vena cava in 20 cases (28%). An intact coronary sinus was rare (2 cases, 3%). Anomalous pulmonary venous connection to a systemic vein was total in 42 (58%) of 72 and partial in 2 (3%) of 72, with obstruction in 24 (55%) of 44. Abnormal pulmonary artery branches (severe hypoplasia, localized stenosis, or discontinuity) were present in 21 (29%), and these obstructive arterial anomalies were associated with a significantly higher prevalence of anomalous pulmonary venous connection (p < 0.01) and of pulmonary venous obstruction (p < 0.01). Cardiac pulmonary venous connections were found in 28 (39%), with the pulmonary veins and the inferior vena cava entering the same atrium in 10 (36%) of 28.

Adolescent↗
PubMed1995

Low human immunodeficiency virus type 1 (HIV-1) DNA burden as a major cause for failure to detect HIV-1 DNA in clinical specimens by PCR.

To determine the sensitivity of a nested PCR procedure for detecting human immunodeficiency virus type 1 DNA in clinical specimens, 553 peripheral blood mononuclear cell samples obtained from 268 human immunodeficiency virus type 1-seropositive subjects were assayed by use of two independent primer sets for each sample. Overall, 1,088 of 1,106 (98.37%) reactions were positive. Investigation of the negative reactions showed that a low viral burden in some infected subjects, rather than primer-template mismatches, was the primary cause for the false-negative PCR results.

CD4 Lymphocyte Count↗
PubMed1993

The behavior of free purine nucleotides in lymphocytes infected with HIV-1 virus.

The purine nucleotide content was examined in various cells before and after HIV-1 virus infection: healthy peripheral blood lymphocytes (PBL) and cultured PBL after infection; the PBL of asymptomatic, ARC and AIDS patients. In all cases, changes in purine nucleotide concentrations were observed. The pattern of purine nucleosides and nucleobases was also evaluated by HPLC in PBL of controls and patients. The analysis was integrated by following the incorporation of a labelled precursor ([14C]formate) into purine nucleotides, which was investigated as an indication of the rate of purine metabolism in these cells. Many interesting variations in the catabolic and of anabolic pathways were observed, demonstrating that the viral penetration affects purine nucleotide metabolism. These results suggest interesting perspectives in AIDS research.

AIDS-Related Complex↗
PubMed1993

Reliability of clinical judgement in evaluation of the nutritional status of surgical patients.

The ability of surgeons to make a reproducible and reliable evaluation of the nutritional status of patients was assessed. Three independent observers assigned 64 patients to one of four nutritional states--normal nourishment, and mild, moderate and severe malnutrition--using a questionnaire and clinical examination. Interobserver variability was analysed using the kappa statistic and reliability by assessing the correlation between the assigned class and total serum protein, haemoglobin, albumin, transferrin and cholesterol levels, weight loss and the results of immunological skin tests. Concordance was observed in 49 of the 64 judgements (77 per cent) and partial agreement in the remainder (kappa = 0.74, P < 0.001). Clinical judgement correlated significantly with albumin, transferrin and cholesterol levels and weight loss (R2 = 0.73, P < 0.001). Surgeons are able to assess nutritional status using clinical judgement.

Adolescent↗
PubMed1993

Discrete subaortic stenosis. Operative age and gradient as predictors of late aortic valve incompetence.

Between January 1969 and May 1990, 100 patients were operated on for discrete subaortic stenosis. Three patients died in the perioperative period. Patients with intrinsic lesions, prosthetic replacement, or extensive operative remodeling of the aortic valve were excluded from the analysis. The 67 remaining patients had a median follow-up of 62 months. Preoperatively, 8 patients had aortic valve competence, 51 had mild incompetence, and 8 patients moderate aortic valve incompetence. At follow-up mild incompetence persisted in 27 and moderate incompetence in 6 patients. In 1 patient it worsened from no incompetence to mild and in another patient from mild to moderate. The probability of aortic incompetence at follow-up was significantly and simultaneously related (multivariate ordinal logistic model) to (1) older age at operation (logarithm of months, p = 0.007), (2) higher preoperative gradient (third power of milligrams of mercury, p = 0.0004), (3) preoperative cardiomegaly (p = 0.04), and (4) surgical myectomy (p = 0.002). There was an interaction between age and gradient (p = 0.03). Two nomograms are proposed as a generalizable aid to decision making. The data support the policy of early repair of subaortic stenosis.

Adolescent↗
PubMed1992

Analysis of purine nucleotides in lymphocytes from healthy subjects and AIDS patients.

The most important purine nucleotides (NAD, AMP, IMP, GMP, XMP, ADP, ATP, GDP, GTP) were analyzed by HPLC in the lymphocytes of healthy subjects and HIV-1 seropositive patients at different stages of the disease (ARC-AIDS). Several differences, which focus attention on the behaviour of purine nucleotide metabolism in the lymphocytes of these patients, were observed.

AIDS-Related Complex↗