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Biomedical subjects

A Oliva

Publications and source records attributed to A Oliva.

At least 109 records · Page 6Linked to original sources
PubMed1993

Fibroblast-derived factors preserve viability in vitro of mononuclear cells isolated from subjects with HIV-1 infection.

OBJECTIVE: Peripheral blood mononuclear cells (PBMC) from HIV-infected subjects have an increased mortality rate (MR) when incubated in vitro for 3 days in a culture medium. We have previously shown that fibroblast-conditioned medium (FCM) can preserve viability, without significant activation, of human lymphocytes in vitro. We therefore tested the ability of two FCM and other factors to reduce spontaneous MR in HIV-positive PBMC. METHODS: PBMC were cultured for 3 days in control medium and medium supplemented with FCM or recombinant cytokines [interleukin (IL)-2, IL-6, IL-7, granulocyte macrophage colony-stimulating factor]. Cells viable at day 3 were counted in a cytofluorimeter after staining with ethidium bromide. DNA was extracted from the cultures and evaluated for the presence of low molecular weight fragmentation. RESULTS: The MR of PBMC from 51 HIV-positive subjects and from 21 healthy controls were 30.1 and 9.5%, respectively (P < 0.0001). The MR was higher in 40 patients with a CD4+ lymphocyte count < 400 x 10(6)/l than in subjects with a count > 400 x 10(6)/l (32.84 versus 20.96%; P = 0.047). IL-2 and FCM significantly reduced MR in HIV-positive subjects (MR: 17.8 and 20.4%; P: < 0.001 and 0.005, respectively). This effect was more evident in subjects with a CD4+ lymphocyte count < 400 x 10(6)/l and in subjects with negative p24 antigenaemia. Cellular proliferation accounts for increased survival in IL-2-supplemented cultures but not in those with FCM. DNA was extracted from fresh PBMC and cells cultured for 3 days for 22 HIV-positive cases. DNA degradation was documented and bands related to an apoptotic mechanism of death observed, especially in subjects with more advanced disease. CONCLUSIONS: Our data suggest that FCM inhibits accelerated cell death in vitro of PBMC isolated from HIV-positive patients.

Adult↗
PubMed1993

Unrecognized injuries in patients referred for emergency microsurgery.

Replantation of amputated parts and emergency microvascular repair of injured extremities are the two most common applications of clinical microsurgery. A major complication of emergency referral of such cases is the existence of the other injuries unrecognized at the time of initial evaluation. We have reviewed this complication within a series of emergency microsurgical cases referred to this unit. Several reports examining this problem of missed injuries exist in the general trauma literature. To our knowledge this study is the first to look at this important problem in the context of acutely injured patients referred for emergency microsurgery. A retrospective analysis of patients referred to Davies Medical Center over a 7-year period was performed. Nine of 1100 patients (0.8%) transferred to our unit for microsurgical evaluation and treatment had unrecognized coexisting injuries that put those patients at high risk for injury-specific morbidity and demanded immediate changes in the original care planned at the time of referral. Brief case histories of these patients are outlined. We review the trauma literature of such injuries. A concise protocol elucidating the guidelines and pitfalls of emergency microsurgical referral is offered.

Adolescent↗
PubMed1993

Increased IL-6 gene expression and production in patients with common variable immunodeficiency.

We have studied IL-6 gene expression and production by in vitro stimulated peripheral blood mononuclear cells (PBMC) isolated from common variable immunodeficiency (CVI) patients. A strong hybridization signal for the IL-6 probe was observed in mRNA extracted from phytohaemagglutinin (PHA)- and PHA/phorbol myristate acetate (PMA)-stimulated PBMC from most of 12 CVI patients analysed. IL-6 production by PHA-stimulated PBMC from 28 CVI patients was evaluated in ELISA and found to be significantly (P < 0.0001) higher than in normal controls. IL-6 production, however, did not correlate with the lymphocyte populations examined, nor with the absolute number of monocytes. We have also showed that IL-6 was able to increase IgM secretion by several Epstein-Barr virus (EBV)-transformed cell lines derived from both normal donors and CVI patients, but it failed to modify substantially the amounts of IgM and IgG produced in vitro by PBMC derived from CVI patients and activated with pokeweed mitogen (PWM) or anti-IgM. Our data indicate that IL-6 gene expression and production is increased in CVI, but CVI cells do not respond to IL-6 with increased production of immunoglobulin.

Adolescent↗
PubMed1993

Abnormalities of lymphocyte subpopulations in CVI do not correlate with increased production of IL-6.

We have determined the percentages and absolute numbers of lymphocyte subpopulations in 49 patients with common variable immunodeficiency (CVI). In vitro production of IL-6 by PHA-stimulated PBMC of 28 patients was also evaluated. Our data indicate profound alterations in the lymphocyte subpopulations evaluated, including increased CD8 cells (these cells outnumbered CD4 cells in 26 cases), severe defect of CD4 cells (< 400/mm3) in 10 cases and reduction of CD19 cells (< 50/mm3) in 11/41 cases. Increased production in vitro of IL-6 by PBMC of CVI patients does not correlate with the absolute numbers of lymphocytes, lymphocyte subpopulations, or monocytes. In addition, IL-6 was unable to significantly modify the amount of PWM-driven IgM production by CVI cells.

Adolescent↗
PubMed1993

Soft-tissue reconstruction in orthopedic surgery. Secondary procedures.

The original consulting microsurgeon should be present to assist in the identification and protection of the vascular pedicle during secondary procedures on microvascular transplants. Flap elevation, trimming, and bone graft placement should be completed during a single tourniquet time, whenever possible. Flaps can easily be resutured on the original bed while the tourniquet is still inflated. Although proximal pedicle transection is possible, it should be avoided by careful planning, because the transplanted tissue cannot be predictably expected to survive, especially with muscle transplants. The distal muscle should be transected only in situations in which the muscle inset is extremely complex. Transection in the extramuscular portion of the main pedicle may require prompt microsurgical repair in immature muscle transplants. The safest approach is to avoid the pedicle whenever additional secondary procedures are necessary following free microvascular tissue transplantation. Placement of vascular pedicles such that the anterior crest of the tibia is avoided if the Ilizarov technique is required permit uncomplicated distraction osteosynthesis. Simultaneous Ilizarov fixation and microvascular tissue transfer are safe, practical procedures for limb salvage. Placement of the Ilizarov fixator at the time of microvascular transplantation provides stable fixation and eliminates the need for a subsequent anesthetic for fixator placement. This form of stabilization, when performed at the time of microvascular tissue transfer, allows the orthopedic surgeon direct visualization of the fracture site as the fixator is placed and eliminates the need for placement of the fixation device through the transplanted tissue. Tissue expansion or suction lipectomy are sometimes needed to optimize the clinical result.

Bone Transplantation↗
PubMed1992

Deficiency of 5'-deoxy-5'-methylthioadenosine phosphorylase activity in malignancy. Absence of the protein in human enzyme-deficient cell lines.

The absence of 5'-deoxy-5'-methylthioadenosine phosphorylase (MTAase) activity in malignant cells, and the putative localization of its gene, suggest that this enzyme deficiency might be due to a genomic alteration also involving a tumour-suppressor gene. We studied the possible occurrence of inactive forms of the protein in two MTAase-negative cell lines, namely K562 and Jurkat, by immunochemical methods. Two highly specific antisera, directed against different epitopes of the phosphorylase [Della Ragione, Oliva, Gragnaniello, Russo, Palumbo & Zappia (1990) J. Biol. Chem. 265, 6241-6246], were used to carry out immunotitration and immunoblotting analyses, as well as to investigate the biosynthesis of the enzyme. No MTAase protein was detected by Western-blotting technique performed under conditions where all the phosphorylase-positive samples gave a clear band at the MTAase subunit molecular mass. No cross-reacting material was observed by a sensitive immunotitration method which permitted the detection of as low as 0.5 ng of protein. Moreover, the results obtained by [35S]methionine-labelling experiments ruled out phosphorylase biosynthesis in the negative cell lines. Altogether, these data suggest that an alteration at the gene level hampering the specific mRNA biosynthesis or resulting in an untranslatable mRNA is the cause of the enzyme deficiency in the MTAase-negative cell lines studied.

Antibody Specificity↗
PubMed1992

Isolation and characterization of human embryonic osteoblasts.

Human osteoblasts were obtained by migration and proliferation of cells from embryonic membranous bone on glass fragments. Light and electron microscopy analyses revealed a typical osteoblast-like appearance with high protein synthesis activity. The cells showed high alkaline phosphatase activity that was associated with plasma membranes and matrix vesicles and was 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] responsive. In contrast to the adult osteoblasts, embryonic cells could not produce detectable levels of osteocalcin, not even in the presence of 1,25(OH)2D3. Osteoblasts grown in multilayers produced a thick extracellular matrix, mainly composed of type I collagen, that mineralized in the presence of 10 mM beta-glycerophosphate. Because of their intrinsic osteogenic capacity, embryonic osteoblasts represent a valuable model for studying the mineralization process in vitro. In addition, the embryonic origin of these cells renders them a precious experimental system for the elucidation of mechanisms at the basis of differentiation of osteoblastic lineage.

Alkaline Phosphatase↗
PubMed1992

Improved salvage of complicated microvascular transplants monitored with quantitative fluorometry.

Quantitative fluorometry has been used to monitor circulation in transplanted toes and cutaneous flaps in our unit since 1982. Analysis of 177 uncomplicated transplants monitored by quantitative fluorometry shows that this technique has low false indication rates for arterial occlusion (0.6 percent of patients) and venous occlusion (6.2 percent of patients). None of these patients was reexplored because of a false monitor reading, and except for single abnormal sequences, monitoring appropriately indicated intact circulation throughout the postoperative period. Quantitative fluorometry has correctly indicated vascular complications in 21 (91.3 percent) of 23 transplants over an 8-year period. The salvage rate (85.7 percent) of the fluorescein-monitored reexplored transplants was significantly higher than the salvage rates of similar reexplored transplants not monitored with fluorescein and of reexplored muscle flaps (which cannot be monitored with the fluorometer used at this unit). These clinical data indicate that quantitative fluorometry is a valid and useful postoperative monitor for transplanted toes and cutaneous flaps.

Fluorometry↗
PubMed1992

Effect of different culture techniques used to induce capacitation on the chromatin stability of human sperm.

To validate an in-vitro bioassay for assessing chromatin stability of human sperm, 38 semen samples from infertile men were studied using sodium dodecyl sulphate, an anionic detergent which disorganizes only the cytoplasmic membrane. Assay sensitivity was 50 sperm, whilst the within- and between-assay variation, and the between-observer variation were found to be within the accepted range for this type of bioassay. The influence of different in-vitro treatments currently used in some clinical assisted fertilization programmes was evaluated: a destabilizing effect occurred in Grade I (stable) and Grade III (swollen) sperm. In the former, all treatments reduced stable sperm; in the latter, a significant (P less than 0.001) increase in swollen sperm was shown with two methods that used Ham's F-10 as culture medium. Different chromatin patterns found in the treated sperm suggest the possibility that the recovered samples could be modified compared to their status at the time of isolation.

Biological Assay↗
PubMed1992

[Not Available].

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Historiography↗
PubMed1992

Hand reconstruction with partial toe and multiple toe transplants.

Microsurgical transplantation of toes to the hand can serve as an excellent method of reconstructing the severely traumatized hand. This article reviews the authors' experience with 188 great-toe and second-toe transplants. Detailed operative sequence and postoperative care are also discussed.

Finger Injuries↗
PubMed1992

Sixth nerve palsy as the initial presenting sign of metastatic prostate cancer. A case report and review of the literature.

Cranial nerve palsies secondary to metastatic prostate cancer are uncommon occurrences. Usually appearing late in the course of the disease, they are associated with a poor prognosis. We report a case of a 71-year-old man who initially complained of diplopia and was found to have a right sixth nerve palsy and hyperdeviation caused by a mass in the clivus. Biopsy of the mass and extensive systemic workup revealed metastatic adenocarcinoma of the prostate gland.

Abducens Nerve↗
PubMed1992

[A clinico-microbiological assessment of patients who have undergone breast reconstruction with a myocutaneous flap of the rectus abdominis].

In plastic surgery a minor complication such as wound infection can cause a lot of damage, because it can put back flap revascularization or it can stop wound healing properly. So the final result is not as good as it should be. In head-neck and in breast reconstruction with prostheses there are set-treatments of antibiotic prophylaxis; while in breast reconstruction with myocutaneous flaps it is very indecisive where antibiotics are concerned. This fact has encouraged us to evaluate bacteria causing infective complications in patients who have had breast reconstruction with TRAMF. In this operation there are 4 conditions which could give rise to microbiological contamination: 1) duration of operation (about 4 hours); 2) wide and prolonged tissue exposure; 3) areas of ischemic tissue or liponecrosis; 4) drainage. In this study we have shown the percentage of bacterial infections and the type of bacteria responsible for these complications in a group of patients who had already undergone breast reconstruction with TRAMF.

Abdominal Muscles↗
PubMed1992

Sperm peritoneal recovery in infertile couples with male factors.

Several studies (1-3) dealing with the presence of spermatozoa in preovulatory peritoneal liquid have shown a low correlation with the situation prevailing in the uterine cervix. Although all previous studies have worked with normospermic populations, we aimed at answering whether alterations of seminal variables are associated with alterations in transportation along the feminine tract. Different sperm migrations (in concentration and motility) were found, depending on the number of seminal variables altered.

Female↗