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Biomedical subjects

A Zanella

Publications and source records attributed to A Zanella.

At least 55 records · Page 3Linked to original sources
PubMed1997

A severe transfusion-dependent congenital dyserythropoietic anaemia presenting as hydrops fetalis.

We describe a case of congenital dyserythropoietic anaemia (CDA) presenting at week 20 of pregnancy with hydrops fetalis and very severe anaemia. Fetal blood examination showed marked erythroblastosis with morphologic alterations while the basic haematological and biochemical tests were in the normal range. The fetus received intravascular red blood cells transfusion at 20 and 25 weeks of gestation. After a caesarean section at week 33 the child became transfusion dependent. Haematological investigations demonstrated that the child is affected by a CDA-like picture which, although morphologically similar to CDA II, is Ham test negative and does not show the typical membrane proteins alterations.

Adult↗
PubMed1997

Sexual transmission of hepatitis C virus to a repeat blood donor.

BACKGROUND: Sexual transmission of hepatitis C virus (HCV) can occur, albeit inefficiently, and this represents a possible cause of community-acquired infections. This study describes a case of asymptomatic HCV infection acquired by a repeat blood donor from her sexual partner. CASE REPORT: A female repeat blood donor showed anti-HCV seroconversion and a slight elevation in alanine aminotransferase. She had a normal physical examination and no clinical symptoms. She admitted a sexual partnership with a man with chronic HCV infection. Genotyping showed subtype 3a infection in both. Nucleotide sequence analysis of the hypervariable region of the viral envelope was performed on five clones obtained from the donor and the partner. Five blood donors with subtype 3a infection were analyzed as controls. The mean homology among clones was 99.3 percent (95% CI, 98.9-99.7) in the donor and 96.8 percent (95% CI, 94.4-99.2) in the partner, which suggests a more recent infection in the woman. The mean homology between donor and partner was 93.4 percent (95% CI, 93.1-93.8), which is different from that between donor and controls (76.2%; 95% CI, 73.3-79.1; difference between means, 17.2%; 95% CI, 16.0-18.4). This suggests that the infection was transmitted to the donor from her sexual partner. Sexual intercourse is the most probable route of transmission, because parenteral risk factors were absent. CONCLUSION: Heterosexual transmission of HCV can occur in the absence of a long-lasting contact, and the infection can be asymptomatic. It remains to be determined whether the sexual partners of HCV-infected subjects should be deferred from blood donation.

Adult↗
PubMed1996

Study of the molecular defects in glucose phosphate isomerase-deficient patients affected by chronic hemolytic anemia.

We have studied four unrelated Italian patients with chronic hemolytic anemia associated with glucose phosphate isomerase (GPI) deficiency. Using intronic primers, we were able to detect the gene alterations on the genomic DNA of the patients. Five different mutations were identified among the eight mutated alleles found: three missense mutations (301A,584T,1028G), one nonsense mutation (286T), and a four nucleotides deletion [Del 1473-IVS16(+2)]. All of these were new except for mutation 1028G, which was previously identified in a Japanese variant (GPI Narita). Two patients were homozygotes (301A/301A and 1028G/1028G), whereas the other two were compound heterozygotes sharing a common mutation [286T/584T and Del 1473-IVS16(+2)/584T]. The missense mutations were found to involve highly conserved amino acids, suggesting that these residues are crucial for the maintenance of the enzyme function. The mutation 286T results in a truncated protein of 95 amino acids in comparison with the 558 of the normal one. The four nucleotides deletion located at the junction of exon/intron 16(5'-TTGGTCGgtgagt-3') is the first GPI mutation affecting a splice site. Moreover one difference from the published sequence (473T-->G) was found in exon five in all of the eight alleles studied and in 30 normal subjects. Correlation was made between mutations, biochemical characteristics of the enzyme, and clinical course of the disease.

Adult↗
PubMed1996

Erythropoietin production and erythropoiesis in compensated and anaemic states of hereditary spherocytosis.

A compensated haemolytic state is defined by decreased red cell life-span without anaemia, i.e. by increased erythropoiesis in the absence of the physiological stimulus for erythropoietin (Epo) production. We evaluated s-Epo levels and the expansion of erythropoiesis (as measured by circulating transferrin receptor, s-TfR) in 32 patients with hereditary spherocytosis (HS) with the aim of verifying whether the enhanced erythropoiesis of compensated haemolysis was Epo-dependent. 20 of the patients (62.5%) had normal Hb values (> 12 g/dl in females and > 13 g/dl in males). Their compensated haemolytic state was the result of up to 8.2 times normal s-Epo and up to 3.9 times normal s-TfR levels, which were maintained by physiological regulation of erythropoiesis, as documented by the inverse dependence of Hb on s-Epo levels. Considering that patients with iron-deficiency anaemia represented the predicted physiological Epo response to anaemia, the observed/predicted in s-Epo ratio (O/P ratio) was calculated in HS patients with anaemia and was used as an index of the adequateness of Epo production. All the anaemic HS patients had an O/P ratio > 1, documenting inappropriately high s-Epo levels. This work demonstrates that the compensated haemolytic state of HS patients is produced by an inappropriately high s-Epo level, and that the pattern of Epo overproduction is a biological characteristic of the disease.

Adolescent↗
PubMed1996

Influence of different hepatitis C virus genotypes on the course of asymptomatic hepatitis C virus infection.

BACKGROUND & AIMS: The association of liver disease with hepatitis C virus (HCV) genotypes mainly refers to patients with serious liver damage; little information is available on symptomless carriers. The aim of this study was to investigate the correlation of genotypes with clinical course, risk factors for infection, and antibody to HCV reactivity in asymptomatic subjects. METHODS: One hundred nine viremic blood donors with at least 1 year of follow-up were studied; 41 underwent liver biopsy. Genotypes were determined by line-probe assay. RESULTS: Genotype 1 was found in 47 (43.1%), genotype 2 in 48 (44%), genotype 3 in 8 (7.3%), genotype 4 in 2 (1.8%), and coinfections in 4 (3.7%). The relative risk (RR) for a raised pattern of alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyltranspeptidase was 2.1 (confidence interval [CI], 1.4-3.2), 1.7 (CI, 1.2-2.4), and 2.8 (CI, 1.6-4.9) in subjects with genotype 1 vs. 0.4 (CI, 0.2-0.7), 0.4 (CI, 0.3-0.7), and 0.4 (CI, 0.2-0.8) in subjects with genotype 2. Chronic hepatitis was found in 68%; the RR of chronic hepatitis was similar for genotypes 1 and 2 (RR, 1.1 [CI, 0.8-1.7] vs. RR, 1.0 [CI, 0.7-1.6]). Reactivity to NS4-derived antigens was infrequent in type 2-infected subjects. CONCLUSIONS: Genotype 2 was as frequent as genotype 1 but associated with less liver function impairment. The high prevalence of chronic hepatitis should be considered in counseling viremic asymptomatic donors.

Adult↗
PubMed1995

Transfusion-transmitted human parvovirus B19 infection in a thalassemic patient.

BACKGROUND: Human parvovirus (HPV) B19 infection has been shown to be transmissible by clotting factor concentrates, most often resulting in asymptomatic seroconversion. So far, no case of B19 transmission due to single-donor transfusion has been documented. CASE REPORT: A case of transfusion-transmitted HPV B19 infection in a 22-year-old female thalassemia major patient is described. She presented with an aplastic crisis; this was followed 1 week later by transitory heart failure and acute tricuspid incompetence. The echocardiogram revealed a grade III tricuspid regurgitation and a floating vegetation on the atrial face of the tricuspid lateral leaflet. The tricuspid regurgitation and vegetation spontaneously disappeared within 15 days. Blood cultures for bacteria were repeatedly negative. IgM anti-HPV B19 seroconversion was documented in the acute phase. B19 DNA was detected by polymerase chain reaction and remained detectable up to 4 months after diagnosis. High-titer IgM anti-HPV and B19 DNA were also found in serum samples collected at the time of donation from one of the donors of the blood transfused before the onset of clinical symptoms. CONCLUSION: This case documents the transmission of HPV B19 by the transfusion of 1 red cell unit and the occurrence of possible transient cardiac involvement in this infectious complication.

Adult↗
PubMed1995

Hepatitis C virus RNA and liver histology in blood donors reactive to a single antigen by second-generation recombinant immunoblot assay.

The clinical significance of single band reactivity (indeterminate pattern) at anti-hepatitis C virus (HCV) second-generation recombinant immunoblot assay (RIBA-2) was investigated in symptomless subjects with normal liver function tests to obtain data for their counseling and clinical management. Serum and hepatic HCV RNA were determined by the nested polymerase chain reaction, and liver histology was evaluated in 40 symptomless blood donors with stable indeterminate RIBA-2 pattern, including 38 reactive to c22-3. All but one had normal alanine aminotransferase (ALT) levels. Two new immunoblot tests, RIBA-3 and INNO-LIA HCV Ab III (LIA-III), which incorporate additional HCV antigens, were also done to assess whether they could identify the viremic subjects. Ten cases (25%, confidence interval 12 to 38) were HCV RNA positive. Three of the HCV RNA-positive and none of the HCV RNA-negative subjects had chronic hepatitis. RIBA-2 strong intensity of reaction (score > 2+) was observed in all the HCV RNA-positive and in 12 HCV RNA-negative subjects. RIBA-3 and LIA-III gave positive results in 9 of 10 and 10 of 10 HCV RNA-positive, but also in 8 of 30 and 24 of 30 HCV RNA-negative subjects. A c-22-3 reactivity score of 4+ by RIBA-3 and E2/NS1 reactivity by LIA-III were both strongly associated with HCV RNA (P < .001). Based on relatively high prevalence of chronic hepatitis in our series (30%), apparently healthy subjects with stable indeterminate RIBA-2 pattern and HCV RNA positivity should be considered for liver biopsy independently of ALT profile.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Buffer-stimulated citrate efflux in Penicillium simplicissimum: an alternative charge balancing ion flow in case of reduced proton backflow?

Organic acids excreted by filamentous fungi may be used to win metals from industrial secondary raw materials. For a future commercial use a high production rate of organic acids is necessary. The conditions under which the commercially used fungus Aspergillus niger excretes high amounts of citric acid can not be maintained in metal leaching processes. However, Penicillium simplicissimum showed an enhanced citric acid efflux in the presence of an industrial filter dust containing 50% zinc oxide. Because Good buffers of high molarity were able to mimic the effect of zinc oxide, the high buffering capacity of zinc oxide and not an effect of the zinc ions was held responsible for the enhanced citric acid efflux. The presence of ammonium and trace elements reduced this buffer-stimulated citric acid efflux, whereas the plant hormone auxine canceled this reduction. This citric acid efflux was influenced by a depolarization of the membrane: the freely permeable compound tetraphenylphosphoniumbromide decreased the citric acid efflux, without decreasing intracellular citric acid or consumption of glucose and oxygen. Vanadate, an inhibitor of the plasma membrane H(+)-ATPase also reduced the buffer-stimulated citric acid efllux. The role of the efflux of citrate anions as an alternative charge balancing ion flow in case of impaired backflow of extruded protons because of a high extracellular buffering capacity is discussed.

Biological Transport↗
PubMed1994

Glucose phosphate isomerase (GPI) "Morcone": a new variant from Italy.

Here we report the 4th Italian case of glucose phosphate isomerase (GPI) deficiency. The propositus is a young man suffering from chronic haemolytic anaemia since birth with occasional transfusion requirement. Biochemical characterization of the defective enzyme revealed increased affinity for F-6-P, decreased affinity for G-6-P and marked thermoinstability. Electrophoretic mobility appeared normal. GPI from both parents showed similar but less pronounced biochemical alterations. The variant described here seems to be different from those previously reported. Thus, we propose the provisional name of GPI "Morcone".

Adult↗
PubMed1994

Excel: a new frontier in haemapheresis.

Haemapheresis is moving towards new prospects. The growing interest in stem cell collection, the increasing demand of single donor platelet units lead to a definition of a "new concept" of cell separator which can offer higher performance, higher selectivity and higher yield in order to guarantee superior quality and pureness of the collected product, but also higher treatment speed and easier usage, for improving user patient donor acceptability and safety level. For these reasons Dideco has developed the new Excel, an extremely innovative automatic blood cell separator, which opens new frontiers in the Haemapheresis field. The main technical features are summarized as following: automatic buffy coat level control through a CCD (charged coupled device), double eccentric-plate separation chamber (1 plate for every procedure), multi-processor system management, advanced user interface through a touch screen display, automatic fluid balancing system through load cell transducers, high-tech ergonomic design. All these innovative technologies are permitting an extremely high performance level higher PLT yield and lower WBC contamination (> 5 x 10(11) PLT with < 5 x 10(6) WBC--double leukodepleted PLT unit easy recoverable), lower procedure time (60 min for one PLT unit, 120 min for 2 unit), higher product quality (lower PLT activation, higher PLT reliability, lower complement activation-C3a), lower ACD consumption (higher withdrawal flow rates are possible), completely automatic procedure management, higher safety level, friendly and guided usage, customized protocols through a complete programmability. All these features and results also offer new standards for the field of haemapheresis through a new generation cell separator: Dideco Excel.

Blood Component Removal↗
PubMed1994

[CO2/O2 anesthesia for the castration of male piglets (preliminary results)].

Introduction of anaesthesia with CO2/O2 (60% to 40%) is possible within 90 and 120 seconds. There are moderate to excessive excitations occurring as part of state II of anaesthesia. Anaesthesia (during castration) in CO2/O2-atmosphere produces excellent analgesia and relaxation. The duration of castration surgery is much shorter under CO2-anaesthesia than without anaesthesia. Blood cortisol levels are significantly higher after castration without CO2-anaesthesia. About 5 minutes after CO2/O2-anaesthesia and castration surgery, piglets are already awake and standing.

Anesthesia, Inhalation↗
PubMed1993

Use of erythropoietin to increase the volume of autologous blood donated by orthopedic patients.

For patients who donate blood for autologous use and undergo major orthopedic surgery, low basal hematocrit (Hct) is the major cause of allogeneic blood exposure. To determine whether recombinant human erythropoietin (rHuEPO) could increase autologous blood procurement and reduce allogeneic blood exposure, a prospective randomized study was conducted in 50 women undergoing total hip replacement who had basal Hct < 40 percent (0.40). Patients were randomly placed in three groups: those receiving placebo, those receiving 300 U of rHuEPO per kg, and those receiving 600 U of rHuEPO per kg every 3 to 4 days for 21 days. Oral iron (125-270 mg/day) was given; in the last 24 patients, 100 mg of iron saccharate was administered intravenously at each donation. At each visit, 350 mL of blood was collected if Hct was > or = 34 percent (0.34). Patients receiving rHuEPO donated a greater amount of blood for autologous use than did patients in the placebo group (4.5 +/- 1.1 vs. 2.8 +/- 0.6 units; p < 0.05) and received a significantly lower amount of allogeneic blood (1.2 +/- 1.4 vs. 0.4 +/- 0.8 units; p < 0.05). No difference between the effects of the two doses of rHuEPO was observed. Iron support was a critical factor in the efficacy of treatment. No untoward effects were observed. The rHuEPO emerged as a safe and effective treatment, with adequate iron support, by which to increase preoperative deposit of autologous blood and to reduce exposure to allogeneic blood for patients with low basal Hct.

Blood Transfusion, Autologous↗
PubMed1993

Iron status in red cell pyruvate kinase deficiency: study of Italian cases.

We investigated the iron status of 33 pyruvate kinase (PK) deficient patients, most of the cases reported in Italy. Serum ferritin (SF) was higher than the upper limit of the range of matched controls in 15/25 (60%) non-transfused patients (median 228 micrograms/l, range 58-3160 v 43, 22-310). Liver siderosis and fibrosis were found in 8/9, and cirrhosis in two who died at age 39 and 42 of complications of iron overload. SF was independent of age, sex, or severity of haemolysis. The prevalence of HLA-A3 antigen in PK deficient patients was not significantly different from that of our healthy population (29.6% v 23%). The HLA-A3 positive, non-transfused patients had significantly higher SF values than the HLA-A3 negative ones (median 675 micrograms/l, range 340-3160 v 145, 58-400). A pedigree study of six high SF-probands indicated that iron overload has a multifactorial pathogenesis. In particular, the association of PK deficiency-induced haemolysis, splenectomy and an additional factor (heterozygosity for idiopathic haemochromatosis, ineffective erythropoiesis) leads to severe iron accumulation. We suggest that monitoring iron status would be useful in PK deficient patients, particularly in splenectomized and HLA-A3 positive ones, to identify those at risk of iron overload and prevent the clinical consequences of iron accumulation.

Adolescent↗