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Biomedical subjects

A Parravicini

Publications and source records attributed to A Parravicini.

31 records · Page 2Linked to original sources
PubMed1980

Chronic asymptomatic HBSAg carriers: histologic abnormalities and diagnostic and prognostic value of serologic markers of the HBV.

Liver histology, the serum "e" antigen system, and DNA-polymerase activity were studied in 68 chronic asymptomatic HBSAg carriers with normal liver chemistries in order to assess the frequency of chronic hepatitis and the diagnostic and prognostic usefulness of serum HBV markers in these subjects. Liver histology was normal in 3 cases, showed nonspecific changes in 46, chronic-persistent hepatitis in 16, and moderate chronic active hepatitis in 3. The "e" antigen and DNA-polymerase activity were positive in 2 and 5 cases, respectively, and were associated with either minimal inflammatory changes or chronic-persistent hepatitis. The "e" antibody was found in 28, evenly distributed among the varios histologic categories; 2 out of 3 patients with chronic active hepatitis carried the "e" antibody. Sixty-four patients have been followed prospectively for 12-30 mo with serial liver tests. During follow-up, 1 patient, with minimal inflammatory changes on liver biopsy and negative for "e" antigen, antibody or DNA-polymerase activity, developed consistently abnormal transaminases, and showed progression to chronic active hepatitis on repeat biopsy. In another patient with chronic-persistent hepatitis, "e" antigen and DNA-polymerase activity reverted to entirely normal serologic status. In our large series, the frequency of chronic hepatitis among HBSAg carriers with normal liver chemistries was somewhat higher than previously reported. In these subjects, the "e" antigen status did not correlate closely with liver histology and did not seem to provide reliable short-term prognostic information.

Adult↗
PubMedDate not supplied

Diagnostic value of serum cholylglycine radioimmunoassay in chronic asymptomatic HBsAg carriers.

The correlation between histological liver abnormalities and fasting serum cholylglycine levels was investigated in 75 chronic asymptomatic HBsAg carriers with normal conventional liver tests, to clarify whether serum CG radioimmunoassay could help in distinguishing the carriers with histological liver damage from those with normal histological findings. Mean (+/- SEM) fasting serum CG levels were 11.6 +/- 1.5 micrograms/dl in 56 carriers with normal liver histology, 14.6 +/- 4.2 micrograms/dl in 16 subjects with CPH and 95.6 +/- 54 micrograms/dl in three carriers with CAH. The incidence of abnormal values (greater than 40 micrograms/dl) among carriers with CAH (66%) was significantly higher than in the other two groups (1.8 and 12.5%, respectively). It is concluded that, among chronic asymptomatic HBsAg carriers with normal conventional liver tests, those who show abnormal serum CG levels are likely to have severe histological damage. This justifies the inclusion of CG radioimmunoassay in the routine follow-up of these subjects. The occurrence of false-positive and false-negative results must be considered if the test is used as an aid in the selection of patients for liver biopsy.

Carrier State↗
PubMedDate not supplied

The preparation of leukocyte-poor red cells for transfusion by a simple cost-effective technique.

A modification of the microaggregate filtration technique for the production of leukocyte-poor red cell concentrate is described. The modified technique, termed 'spin, cool, and filter', removed leukocytes more efficiently from relatively fresh blood than the original microaggregate filtration procedure. The residual leukocyte content of 4- to 9-day-old units processed by the modified procedure averaged less than 0.4 X 10(9) white cells per unit. The microaggregate filtration technique, supplemented by buffy-coat exclusion, removed more than 93 percent of the units' white cells. These red cell products were prepared easily and did not elicit febrile reactions in highly susceptible patients.

Blood Preservation↗
PubMedDate not supplied

Red cell alloantibodies in thalassemia major. Results of an Italian cooperative study.

Clinical and serological data on 1435 Italian thalassemia major patients were collected during a cooperative study involving 19 centers in 10 regions. The main findings were as follows: 18 percent of the patients were under 6 years of age, 63 percent between 6 and 15, and 19 percent over 15. Forty-one percent had undergone splenectomy. Sixty-two percent of the patients were maintained at pretransfusion hemoglobin levels higher than 10 g per dl, 36 percent between 8 and 10 g per dl, and 2 percent below 8 g per dl. Overall, 5.2 percent of the patients had clinically significant red cell alloantibodies (136 alloantibodies in 74 patients). One-half of the immunized patients had more than one and one-fourth had more than two alloantibodies. The specificities of the 136 alloantibodies were almost exclusively confined to the common antigens of the Rh, Kell, Kidd, and Duffy systems, in that decreasing order of frequency. The antibody screening procedure, using a low-ionic-strength solution antiglobulin test against a three-red-cell panel and the patient's own red cells (autocontrol) with a serum to cell ratio of 100 to 1 was shown to be an adequate technique for red cell antibody detection.

Adolescent↗
PubMedDate not supplied

The manual preparation of leukocyte-poor red cells for transfusion by a new filter.

Standard and buffy-coat-depleted red cell concentrates were filtered through a new cellulose acetate filter with a manual procedure. No residual leukocytes could be detected in 19 of the 21 filtered units. Extracellular hemoglobin after red cell filtration and concentration never exceeded 10 mg per unit. No transfusion reaction occurred in 10 recipients with potent lymphocytotoxic antibodies in their serum and histories of febrile transfusion reactions. This filter allows the preparation of leukocyte-poor red cell units with a safe, simple, and effective manual procedure.

Blood Transfusion↗
PubMedDate not supplied

Leukocyte depletion of red cell units at the bedside by transfusion through a new filter.

Standard packed red cell (PRC) units can be depleted of leukocytes and platelets if they are transfused through a blood administration set in which the usual 170-mu filter has been replaced by a leukocyte removal filter (Sepacell R-500). During a 6-month period, 1550 PRC units were transfused through this filter in 611 transfusions to 80 multitransfused patients with thalassemia who had had a patient reaction rate (PRR) of 63 percent and a transfusion reaction rate (TRR) of 13 percent when given standard PRC or buffy-coat-depleted PRC. When given filtered PRC, PRR and TRR became 3.7 percent and 0.5 percent, respectively. The effectiveness of the filter was also evaluated in vitro. By filtering 2 standard PRC units through the same filter, median values (and ranges) for red cell recovery and for residual leukocytes and platelets were 87 percent (83-92), 6.1 X 10(6) (0-100), and 2.7 X 10(9) (0.6-9.7), respectively. Although refinements are needed to improve standardization of the filter and to increase red cell recovery (which is low when 1 unit is filtered through one filter) and blood administration rate, the ability to provide leukocyte-free red cells prepared at the bedside for virtually all recipients appears to be a realistic goal.

Blood↗
PubMedDate not supplied

Quality assessment of transfusion practice in elective surgery.

A program of quality assurance (QA) was adopted to improve blood transfusion practice in elective surgery at a large urban hospital. For this purpose, a cooperative multidisciplinary group was formed, key indicators were identified, and an organization was set up. Data collected by this organization in the 1-year period needed for implementation of the program indicated that blood misuse was common practice. In fact, overrequest, overtransfusion, excessive reconstitution of whole blood (i.e., concurrent transfusion of red cells and fresh-frozen plasma), and underuse of predeposit were found in all ten surgical departments of the hospital. In a pilot study, data were collected from one surgical department during and after the implementation phase of the QA program; comparison of these data showed a postimplementation reduction of about two thirds in overtransfusion, whereas overrequest, reconstitution of whole blood, and predeposit rates remained unchanged. These results prompted continuation of the program in order to reach a definitive evaluation of its effectiveness.

Blood Transfusion↗
PubMedDate not supplied

Use of IgM monoclonal reagents licensed for tube tests in column agglutination technology.

BACKGROUND: Red cell (RBC) phenotyping using column agglutination technology (CAT) is currently limited by the reagents formulated in the system. To overcome this limitation, it was investigated whether monoclonal IgM reagents licensed for use with tube tests produced valid results with CAT. STUDY DESIGN AND METHODS: Commercial CAT, does not contain antisera, was used to evaluate Procedures A (40 microL of reagent and 10 microL of 4% RBCs) and B (50 microL of reagent and 50 microL of 0.8% RBCs) with or without incubation at room temperature. In Study 1, reagents were tested to determine whether potentiators inhibit the passage of antigen-negative RBCs through the column. In Study 2, CAT sensitivity was measured by the use of potency titrations to define a procedure for each reagent that matched or exceeded that of the tube method. In Study 3, the specificity of each reagent was determined in parallel with the CAT and tube tests. Typing of 1644 samples was performed. RESULTS: Study 1: Free passage was obtained with all reagents. Study 2: Immediate-spin methods using CAT produced the same results as the tube method. Study 3: With 8048 comparisons made, discrepant results were found in 32 transfused patients and in 6 cord blood samples, mainly with Lewis reagents. With comparison of CAT and the standard tube method, complete agreement was obtained with Kell reagents, 99.9-percent agreement with Kidd reagents, and 98.9-percent and 99.4-percent agreement with Lewis reagents. CONCLUSION: Most examined reagents seem suitable for use with CAT.

Aged↗
PubMedDate not supplied

[Infectious complications in organ transplantations (author's transl)].

On the basis of various reported experiences the Authors emphasize the importance of infectious complications in organ transplantations. As a matter of fact these complications occur in a very high percentage of cases (over 50%); they have severe prognoses and are caused by such agents as bacteria, fungi, viruses, protozoa and metazoa. The Authors suggest microbiological monitoring of the recipient before, during and even after the transplantation, in order to single out the etiologic agent as rapidly and accrately as possible and thus to decide upon a suitable therapy.

Bacterial Infections↗