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Biomedical subjects

M Ozcan

Publications and source records attributed to M Ozcan.

At least 73 records · Page 4Linked to original sources
PubMed2000

Effect of surgical denervation on the viability of inferior epigastric neurovenous flaps in the rat.

The purpose of this study was to examine how the inferior epigastric neurovenous flap in the rat reacts to surgical denervation. The survival of a denervated flap was compared with that of an innervated flap. A 2 x 2-cm flap was raised in 30 female Wistar rats assigned randomly to six groups of 10 rats each: group 1, innervated neurovenous flap; group 2, denervated neurovenous flap, acute model; group 3, denervated neurovenous flap, chronic model; group 4, innervated inferior epigastric island flap; group 5, denervated inferior epigastric island flap, acute model; and group 6, control, composite graft. Acute denervation produced a significant decrease in the survival of the inferior epigastric neurovenous flap (p < 0.05). The surviving area of the innervated flaps decreased from 94+/-14% (mean +/- standard deviation) to 16+/-34% by acute denervation. Chronic denervation was effective in decreasing flap necrosis in these flaps (survival, 99+/-5%). There were no differences between the average viable area of the standard inferior epigastric flap in the denervated and innervated groups.

Animals↗
PubMed2000

Breast reconstruction with the internal mammary artery pedicled fasciocutaneous island flap: description of a new flap.

Postburn skin contracture of the inframammary sulcus is a commonly encountered problem, especially in pubescent girls. Release of these contractures is commonly performed by split-thickness skin grafts, which necessitate further operations as the child grows. If the contracture of the inframammary sulcus is only one-sided, then the inframammary tissues of the contralateral breast can be used for reconstruction with the fasciocutaneous island flap. The donor site can be closed primarily without disrupting the appearance of the healthy breast, and the skin incision is hidden in the inframammary sulcus. The flap described here is a fasciocutaneous island flap based on the internal mammary artery and the perforating branches to the skin and subcutaneous tissues that the artery gives off as it leaves the thoracic cavity through the seventh intercostal space. After being supported by fresh cadaver and angiographic studies, the flap was applied to seven female patients (four of whom were pubescent) with burn contracture of the breast; satisfactory results were obtained. In defects of the mammary region that required volume or for which repair by skin grafting was planned, in sternal defects, or in young patients, this flap seems to be the best choice.

Adolescent↗
PubMed1999

Central response selection is present during memory scanning, but hand-specific response preparation is absent.

Two experiments were performed to replicate the results of Ilan and Miller that response selection but no response-hand specific preparation is present during memory scanning. Letter-case determined which hand would respond, while memory set membership status determined whether the response was to be executed (go) or withheld (nogo). In Exp. 1, the LRP was observed as an index of response-hand specific preparation. In Exp. 2, the consistency effect derived from the response priming paradigm was observed as an index of more central response selection. The results replicate those of Ilan and Miller and suggest that central response selection is present during short-term memory scanning, but hand-specific response preparation is absent. Apparently, preliminary information is transmitted to the response selection stage during memory scanning, a finding that is inconsistent with serial stage models, but memory scanning interferes with hand-specific response preparation.

Functional Laterality↗
PubMed1999

Hematopoietic stem cell transplantation from non-replicative hepatitis B virus carriers is safe.

BACKGROUND/AIMS: Hepatitis B virus can cause serious problems in individuals undergoing organ transplantation. The aim of this study was to evaluate the hepatic events among HBs-Ag positive recipients and HBs-Ag negative recipients who received products from hepatitis B virus carriers. METHODS: A total of 151 patients received an allogeneic hematopoietic stem cell transplantation at the Department of Hematology-Oncology, University of Ankara, between June 1989 and June 1998. Among these, eight HBs-Ag positive and four HBs-Ag negative recipients received a product from a hepatitis B virus positive donor. The median follow-up period for these 12 patients was 13.2 months. RESULTS: Three of the eight HBs-Ag positive recipients died (one from hepatic failure); of the remainder, two are HBs-Ag negative, two HBs-Ag positive with normal liver injury tests and one HBs-Ag positive with elevated ALT levels. Of the four HBs-Ag negative recipients who received stem cells from a hepatitis B positive donor, two died; none of the patients in this group became HBs-Ag positive after transplantation. CONCLUSION: Hepatitis B virus infection is a common problem in patients being considered for allogeneic hematopoetic stem cell transplantation, especially in areas where hepatitis B virus infection is endemic. We believe that the presence of HBs-Ag positivity is not an absolute contraindication for allogeneic hematopoetic stem cell transplantation unless the hepatitis B virus is in a replication phase.

Adolescent↗
PubMed1999

The impact of the CD34+ cell dose on engraftment in allogeneic peripheral blood stem cell transplantation.

Forty-five patients who underwent allogeneic peripheral blood stem cell transplantation (PBSCT) were evaluated in order to investigate any relationship between CD34+ cell dose given and hematological recovery. Granulocyte counts > 1.0 x 10(9)/L and platelet > 50 x 10(9)/L were considered as hematological recovery. Three different regimens were used for mobilization, by adjusting the recombinant granulocyte colony stimulating factor (rhG-CSF, Roche) dose. The first group (n = 3), whose donors mobilized with 5 micrograms/kg/d s.c. rhG-CSF received a mean of 5.9 x 10(6)/kg (95% confidence interval for mean (CI); 2.4-9.3) CD34+ cells. The second group (n = 37), mobilized with 10 micrograms/kg/d s.c. rhG-CSF and the third group (n = 5) mobilized with 15 micrograms/kg/d s.c. rhG-CSF, received a mean of 5.7 x 10(6)/kg (95% CI; 4.6-6.75) and 6.56 x 10(6)/kg (95% CI; 4.57-8.55) CD34+ cells, respectively. CD34+ cell dose was 5.82 x 10(6)/kg (95% CI; 4.97-6.68) for all the patients. All patients received rhG-CSF from day +1 until attaining granulocyte count > 1.0 x 10(9)/L for three consecutive days. Median granulocyte and platelet engraftment days for the whole group was 15 (range; 11-44) and 14 (11-54) days respectively. There was a close correlation (r = -0.301, p < 0.05) between the CD34+ cell dose and granulocyte recovery for the whole group. When these analyses were performed separately within groups, this correlation was also found significant for the first group (r = -0.99, p < 0.05) for granulocyte recovery. On the contrary the same analysis did not reach significance for the other groups, nor for platelet recovery for the whole group (r = 0.039, p = 0.821). We calculated a minimum dose of 4 x 10(6)/kg CD34+ cells for a safe alloPBSCT. There was no difference between patients who received more than 5 x 10(6)/kg CD34+ cells, and those who received more than 2 x 10(6)/kg and less than 5 x 10(6)/kg CD34+ cells. In conclusion, we have demonstrated a correlation between the CD34+ cell dose given and faster hematological recovery for alloPBSCT patients.

Adolescent↗
PubMed1999

Autoimmune thrombocytopenia in a patient with small cell lung cancer developing after chemotherapy and resolving following autologous peripheral blood stem cell transplantation.

A 46-year-old white male with small cell lung cancer (SCLC) limited to the thorax developed autoimmune thrombocytopenic purpura (AITP), following a cyclophosphamide, paclitaxel and G-CSF-containing regimen for peripheral blood stem cell (PBSC) mobilization. AITP associated with small or non-small cell lung cancer has been reported. We considered that the AITP in this case may be a part of paraneoplastic syndrome, which is frequently seen in patients with SCLC. The patient received HDC and autologous PBSC transplantation (APBSCT) for SCLC and the AITP resolved following transplantation, thus supporting the concept of HDC + APBSCT for the treatment of autoimmune diseases.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

Treatment of aregeneratoric anemia following an ABO-incompatible allogeneic peripheral blood stem cell transplantation: a case report.

Aregeneratoric anemia (AA) occurs rarely after ABO-incompatible allogeneic peripheral blood stem cell transplantation (alloPBSCT), and its management is generally difficult. Here, we present a 31-year-old white man with myelodysplastic syndrome who developed AA after receiving stem cells from his human leukocyte antigen (HLA) identical, but ABO-incompatible sibling. Because his anti-A antibody titers were high, therapy with conventional doses of erythropoietin and prednisolone failed to treat the AA. Following 8 cycles of plasma exchange and higher doses of erythropoietin and prednisolone as well as danazol administration, anti-A titers decreased, and his anemia improved significantly. In conclusion, to treat and obtain a low titer of antibodies in a patient with AA following an ABO-incompatible alloPBSCT, higher doses of erythopoietin and corticosteroids associated with plasma exchange have to be used.

ABO Blood-Group System↗
PubMed1999

A retrospective comparison of allogeneic peripheral blood stem cell and bone marrow transplantation results from a single center: a focus on the incidence of graft-vs.-host disease and relapse.

To detect the effect of the stem cell source, allogeneic peripheral blood stem cell transplantations (alloPBSCTs) performed between 1995 and 1997 from human leukocyte antigen (HLA)-identical siblings in 40 patients with acute and chronic hematological disorders were compared with a historical group of 40 patients with similar variables who had received allogeneic bone marrow transplants (alloBMTs) between 1993 and 1995. Patients in both groups were identical except that both the recipient and the donor ages were, on average, higher in the alloPBSCT group (26 vs. 36 [p = 0.005] and 27 vs. 32 [p = 0.024], respectively). Patients received similar therapy excluding posttransplant granulocyte colony-stimulating factor administration (97% in alloBMT vs. 12.5% in alloPBSCT). The median time to reach neutrophil counts >0.5 x 10(9)/L and platelet counts >20 x 10(9)/L was 13 and 14 days, respectively, in patients receiving alloPBSCTs compared with 19 and 27 days in patients receiving alloBMTs (p = 0.0014 and p = 0.0002). The alloPBSCT group required similar transfusions of red blood cells or platelets. The incidence of grade II-IV acute graft-vs.-host disease (aGVHD) was similar in both groups. However, chronic GVHD (cGVHD) of all grades developed in 78.1% of patients in the alloPBSCT group after a median follow-up period of 12.5 (range 0.5-34) months. In alloBMT recipients, cGVHD of all grades developed in 21.4% after a median follow-up period of 38 (range 0.5-62) months (p = 0.00001). Day 100 transplant-related mortality was also similar: 20% (8 of 40) in the alloBMT patients and 17.5% (7 of 40) in the alloPBSCT group. Although not statistically significant, a relatively higher relapse rate occurred in the alloBMT group (21.4 vs. 10.7%). The estimated disease-free survival in month 24 was 51.3% for alloBMT and 54.6% for alloPBSCT, and the estimated overall survival in month 24 was 56.1% for alloBMT and 64.6% for alloPBSCT. In conclusion, this retrospective comparison suggests that alloPBSCT from HLA-identical donors is associated with faster engraftment, fewer transfusions, and no greater incidence of aGVHD, but a high incidence of cGVHD.

Adolescent↗
PubMed1999

Differences in liver pathology and clinical outcome between two patients with hepatitis B virus and graft versus host disease.

Our two patients undergoing allogeneic bone marrow transplantation (AlloBMT) had both Hepatitis B virus (HBV) and graft-versus-host disease (GVHD). In the first patient, liver enzymes elevated three months after AlloBMT, and GVHD was diagnosed. Two weeks after the diagnosis of GVHD, HBsAg appeared in his serum. At that time, liver biopsy was not able to discriminate two disorders, but his sequential liver biopsies disclosed GVHD. Despite the patient was treated with cyclosporin A (CsA), he died for chronic GVHD. In contrast to the first patient, the second patient had HBsAg prior to GVHD. His liver enzymes deterioration was detected in the first month after AlloBMT, and reached the highest level in the third month while withdrawing CsA. In the fifth month he developed scleradermatous skin changes, and skin biopsy revealed chronic GVHD, whereas concurrent liver biopsy revealed chronic active hepatitis. This observation showed that immunosuppressive conditions such as GVHD or its prophylaxis may affect the appearance of liver pathology caused by HBV, which depends on the time of GVHD development, and the duration and depth of GVHD prophylaxis.

Adult↗
PubMed1999

Preliminary report: the distally pedicled dorsoulnar forearm flap for hand reconstruction.

In this paper, a new flap for the coverage of soft tissue defects in the hand is described. To obtain a distally pedicled dorsoulnar flap, the dissection of the standard dorsoulnar flap is continued distally under the descending branch of the dorsal branch of the ulnar artery onto the dorsum of the wrist after the dorsal branch of the ulnar artery is ligated and divided. Our modification of the standard dorsoulnar flap converts this flap to a distally based flap, which provides a potentially longer pedicle and increases the arc of rotation of the flap. Two successful cases are reported.

Adolescent↗
PubMed1999

Salvage of the lower leg using a reversed long free fibular flap.

The advantages of end-to-side anastomoses have been well documented in microvascular surgery. The vessels of the fibular flap do not usually permit end-to-side anastomosis to recipient vessels in the proximal part of the lower leg because the pedicle length of the free fibular flap is usually too short. Therefore, vein grafts are used to elongate the vessels. If a harvested long free fibular flap that is used to bridge a massive defect of the tibia is reversed and placed into the medullary cavity of the tibia, the flap vessels can be anastomosed, using the end-to-side technique, to the recipient vessels without vein grafts in the distal part of the lower leg. Thus, the flap artery (the peroneal artery) fills in a retrograde fashion. The patient reported was reconstructed with a reversed long free fibular flap. The postoperative period was uneventful. The patient can stand and walk with a protective shoe 2 years postoperatively.

Anastomosis, Surgical↗
PubMed1998

Autonomic dysfunction in vitamin B12 deficiency: a heart rate variability study.

This study was arranged to examine whether vitamin B12 deficiency may cause autonomic dysfunction. Time-domain and long-term frequency-domain heart rate variability parameters from 12 patients with pernicious anemia were compared to 12 age and sex matched controls. In B12 deficient patient group time-domain parameters; SDNN (100.4 +/- 37.86 vs. 131.91 +/- 26.94, P = 0.05), SDANN (87.00 +/- 37.77 vs. 118.83 +/- 26.22, P = 0.05) SD (39.41 +/- 13.32 vs. 53.41 +/- 15.39, P = 0.0221), rMSSD (21.41 +/- 10.00 vs. 28.5 +/- 8.42, P = 0.046) were significantly lower when compared to controls. Difference in pNN50 between groups were not statistically significant. In B12 deficient patients frequency-domain parameters; total power (23.08 +/- 9.89 vs. 34.75 +/- 9.56, P = 0.0078), low frequency power (13.5 +/- 6.57 vs. 22.75 +/- 7.25, P = 0.0069) and high frequency power (7.58 +/- 4.25 vs. 11.58 +/- 3.80, P = 0.0175) were significantly lower when compared to controls. It was concluded that B12 deficiency may cause autonomic dysfunction.

Adult↗