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Biomedical subjects

A Oliva

Publications and source records attributed to A Oliva.

At least 91 records · Page 5Linked to original sources
PubMed1995

[202 toe transfers to the hand].

This retrospective study analyzed 202 toe-to-hand transplants performed over the last 20 years at the Davies Medical Center, San Francisco (USA). The overall success rate was 97%. Toe transplants for finger reconstruction yielded optimal functional and cosmetic results due to their anatomical similarity to fingers. The great toe was preferably used for thumb reconstruction, whereas the other toes were used for reconstruction of the long fingers. Early reconstructions, multiple simultaneous toe transplants, and interventions combining toe transplantation with free flaps seemed to be advantageous because of shorter rehabilitation and comparable results.

Activities of Daily Living↗
PubMed1995

[Variations in fibronectin plasma levels after surgical stress].

Depletion of reticuloendothelial system following major operations or trauma closely correlates with a decrease of plasmatic levels of fibronectin. Aim of the study is to evaluate the changes in plasma fibronectin levels after a surgical stress. Twenty patients who underwent elective gynecological surgery for a variety of pathological condition were the subject of our study. Circulating levels of fibronectin showed a significative decrease, as compared to preoperative values, and returned to normal during the second postoperative day. The recovery to normal values of this plasma glycoprotein was associated, in our patients, with a normal postoperative course.

Adult↗
PubMed1995

Aza and diaza bioisosteric anthracene-9,10-diones as antitumor agents.

Synthetic routes to aza and diaza bioisosteres related to the anthracene-9,10-dione, mitoxantrone, have been developed. The antitumor properties of these chemotypes are compared with those exhibited by the corresponding carbocyclic analogues. The sensitivity of the expressed cytotoxicities on the position(s) of the nitrogen atom(s) are discussed in terms of potential cellular targets. Several analogues show potential for clinical evaluations.

Animals↗
PubMed1994

Influence of calorie source on the physiological response to parenteral nutrition in malnourished rabbits.

The present study was designed to investigate whether calorie source influences sodium and water metabolism and sympathetic activity during parenteral nutrition (PN). 20 New Zealand rabbits were starved until a mean weight loss of 18% was achieved and then re-fed for 6 days with 2 formulae of PN with different glucose-fat proportions. In the Glucose group (n = 9), 70% of non-protein calories were given as glucose while in the Lipid group (n = 11), 70% of non-protein calories were administered as lipids. Rabbits with a high glucose intake showed significantly higher weight gain (151 +/- 87 vs. 52 +/- 7 g, P = 0.01), water cumulative balance (542 +/- 132 vs. 411 +/- 87 ml; P = 0.02) and urinary metanephrine excretion (0.42 +/- 0.12 vs. 0.30 +/- 0.1 mumol/d, P = .03). Only in this group, urinary metanephrines correlated positively with water and sodium balances (r2 = 0.6; P = 0.02 and r2 = 0.7; P = 0.009 respectively). The Glucose group showed 2 different responses and in a second experiment 10 additional rabbits were added to this group to allow a statistical analysis of the response pattern: half of the animals increased their extracellular water (ECW) compartment while the remaining animals did not. The former group had higher sodium balance (13.9 +/- 8 vs. 4.3 +/- 5; P = 0.004) and wet lung weight (8.9 +/- 0.9 vs. 7.9 +/- 0.8; P < 0.05) after re-feeding and, at the beginning of PN, their serum aldosterone concentration were also higher (221 +/- 11 vs. 130 +/- 47 pmol/l; P < 0.05). In conclusion, glucose based PN appears to increase sympathetic activity and induce spurious weight gain due to markedly positive wate and sodium balances. Plasma aldosterone concentration at the end of starvation period influences sodium retention and ECW expansion during high glucose re-feeding.

Journal Article↗
PubMed1994

Microvascular vein-graft patency in the rat model.

This study establishes a controlled model, to examine the patency rates of simple, arterial and venous anastomoses, compared to vessel repairs performed with 10-mm, size-matched, interpositional, vein grafts in the rat femoral artery and vein. Patency rates in two control groups, consisting of 68 Sprague-Dawley rats in which simple, femoral-vessel repairs were performed, were compared to three experimental groups, consisting of 94 animals in which the femoral vessels were repaired with interpositional vein grafts. No statistically significant difference was found in the patency rates of arterial (p = 0.487) or venous repairs (p = 0.472) in the control groups. Nor was a significant difference found in arterial vein-graft patency (p = 0.560) or venous vein-graft patency (p = 0.862), when compared to the control groups. This study illustrates that, in the controlled laboratory setting, 10-mm, size-matched, interpositional, vein grafts have statistically the same patency rates as simple repairs of the rat femoral artery and vein.

Anastomosis, Surgical↗
PubMed1994

Microvascular vein grafts in the rat cutaneous free-flap model.

This study utilizes the rat free groin-flap model to evaluate the survival of free flaps following revascularization with interpositional vein grafts. One hundred and fifty-three Sprague-Dawley rats were divided into a control group in which the groin flap was revascularized by simple end-to-end anastomosis, and three experimental groups revascularized with 10-mm, size-matched, interpositional, vein grafts to the femoral artery (Experimental Group 1), to the femoral vein (Experimental Group 2), and to both arterial and venous femoral vessels (Experimental Group 3). No statistically significant difference was noted in survival rates, when the experimental groups were compared to the control group (p1 = 0.619, p2 = 0.677, p3 = 0.666). As demonstrated by this study, free-tissue transfers in the rat, utilizing 10-mm, interpositional, vein grafts that are size-matched, and performed in a controlled laboratory setting, have the same survival rates as those revascularized by primary arterial and venous repairs.

Anastomosis, Surgical↗
PubMed1994

T cell receptor gene rearrangements and cytotoxic activities of clones isolated from tumour-infiltrating lymphocytes (TIL) from melanoma patients.

The lymphocytes which infiltrate tumours and are grown in vitro to be used in adoptive immunotherapy are often characterized by dominant rearrangement of their T cell receptor (TCR) genes. To investigate the frequency and function of cells contributing to the 'dominant' rearrangement, we have cloned two bulk cell lines of TIL derived from melanoma patients (TIL-1 and TIL-5). These IL-2-propagated TIL cell lines had a CD8+ phenotype and exerted strong cytotoxic activity against autologous melanoma cells, but not against the natural killer (NK)-sensitive K-562 cell line or LAK targets such as Daudi cells. We derived 40 clones from TIL-1 and 23 from TIL-5. All tested clones were CD3+, CD4-, CD8+ and expressed the alpha/beta TCR. From TIL-1, 27 of 40 clones, and 13/19 of the TIL-5 clones lysed autologous tumour cells. In contrast to the NK-negative bulk cultures, K-562 killing was detected in 21 of the TIL-1 clones and 17 of the TIL-5 clones. TIL-1 contained eight clones and TIL-5 two clones with lytic capacity against neither autologous tumour cells nor the K562 cell line, although these clones possessed lytic potential as evidenced in a lectin-mediated lysis assay. LAK activity was not detected in most clones. Cytotoxic activity against autologous tumour could be inhibited by preincubation with anti-CD3 or anti-HLA class I MoAbs. Of the 34 TIL-1 clones analysed, 15 shared a rearranged TCR beta EcoRI restriction fragment of approximately 9.5 kb with the bulk culture. Clones sharing the EcoRI 10.5-kb dominant band present in TIL-5 bulk culture were also isolated. When the pattern of TCR beta rearrangement was compared with the cytotoxic functions, the following conclusions could be drawn: (i) clones contributing to the dominant band had heterogeneous functions. Most killed autologous tumour cells, but clones with no cytotoxic activity or even with no proliferative capacity in response to autologous tumour cells were also detected among those contributing rearrangement; (ii) some clones that share an apparently identical rearranged band different from the 'dominant' rearrangement, may demonstrate the same cytotoxic function. In addition, our data suggest that many of the clones that share the dominant rearrangement originated from diverse progenitors. The high frequency of clonally diverse anti-tumour reactive TIL is likely to be a reflection of the in vivo selection of the TCR repertoire at the site of tumour.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibodies, Monoclonal↗
PubMed1994

Cultures of human embryonic osteoblasts. A new in vitro model for biocompatibility studies.

Cell populations derived from human embryonic bone were isolated according to the ability of osteoblasts to migrate from bone onto glass fragments. Morphologic and biochemical assays showed (1) osteoblast-like appearance; (2) elevated alkaline phosphatase 1,25(OH)2D3 responsive activity associated with plasma membranes and matrix vesicles; (3) production of a thick extracellular matrix, mainly composed of Type I collagen, which mineralized in the presence of 10 mM beta-glycerophosphate; and (4) higher growth rate and viability when compared with their mature counterpart. Cultures of embryonic cells were challenged with particles of several biomaterials, and their effects on morphology, vitality, and osteogenic capacity of the cultured cells were tested. Stainless steel, titanium alloy, Co-Cr-Mo alloy (vitallium), carbon fiber-reinforced polybutylene terephtalate, ultra-high molecular weight polyethylene, ceramic, calcium phosphate, and hydroxyapatite did not exert any significant deleterious effects on the cultured human osteoblasts.

Alkaline Phosphatase↗
PubMed1994

HPLC determination of polyethylene glycol 400 in urine: oligomeric profile in healthy and celiac disease subjects.

The absorption of orally administered polyethylene glycol (PEG) has been used to assess intestinal permeability. We describe a simple HPLC technique to determine the oligomeric profile of PEG excreted in urine. We measured the total (%) PEG excreted in 6 h and the ratio of the four smallest oligomers to the three largest oligomers (expressed as mean percentages). The proposed method differentiates distinct groups of subjects with varying degrees of intestinal permeability detected by intestinal biopsy. The percent of PEG excreted and the oligomer ratio values for healthy subjects were, respectively, 30.1 +/- 3.87 and 0.35 +/- 0.03; for celiac patients on a gluten-free diet, 24.5 +/- 6.65 and 0.45 +/- 0.16; and for celiac patients, 15.0 +/- 5.93 and 1.12 +/- 0.55.

Adult↗
PubMed1994

Simultaneous free-tissue transfer and Ilizarov distraction osteosynthesis in lower extremity salvage: case report and review of the literature.

The last decade has witnessed the refinement of microvascular tissue transplantation and its application in treating difficult open wounds. Nonetheless, severe type III tibial injuries continue to challenge reconstructive surgeons. The clinical presentation and surgical treatment of a type IIIB tibial fracture, complicated by long-standing chronic osteomyelitis, angulation deformity, and bone shortening, is presented. This case illustrates the benefit of combining microvascular transplantation of distant tissues with the Ilizarov technique of distraction osteosynthesis in the treatment of complicated lower extremity injuries.

Abdominal Muscles↗
PubMed1993

Effect of retinoic acid on osteocalcin gene expression in human osteoblasts.

It is well known that the expression of osteocalcin, the only recognized osteoblast-specific protein, is regulated by 1 alpha-25-dihydroxyvitamin D3 through a distinct vitamin D3 receptor and a cis-acting DNA response element. In addition, recent data obtained with plasmid constructs have shown a positive interaction between retinoic acid activated receptor(s) and the osteocalcin gene promoter. Our studies, carried out on primary cultures of human osteoblasts, have demonstrated for the first time the activation of the osteocalcin gene expression by retinoic acid. Moreover, a remarkable synergistic effect between the hormonal forms of vitamin A and D3 on the synthesis of this bone-specific protein was observed.

Calcitriol↗
PubMed1993

Salvage of wounds following failed tissue transplantation.

During the past 20 years, 972 microvascular transplantations have been performed for 783 patients, with an overall failure rate of 6.2 percent. Fifty-four of the 60 failed transplantations were available for long-term follow-up and were retrospectively reviewed with respect to the original indications for transplantation, the number, and the type of salvage procedures performed following transplant failure. This study illustrates that the choice of salvage procedures performed following transplant failure depends on the original indications, the location, and the severity of the resultant wound. Failure following transplantation for coverage of contour defects or unstable wounds can often be managed by non-microsurgical methods. In contrast, when the indications for transplantation included the transfer of specialized tissues for thumb or digit reconstruction, the restoration of motor or sensory function, or the coverage of a limb-threatening wound, requirements for reconstruction could be satisfied only by a second successful tissue transplant. Eighteen of the 54 cases underwent an additional transplantation, with an 89 percent success rate.

Adolescent↗