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Biomedical subjects

M Kara

Publications and source records attributed to M Kara.

At least 37 records · Page 2Linked to original sources
PubMed2001

Successful removal of a giant recurrent mediastinal liposarcoma involving both hemithoraces.

Primary liposarcomas of the mediastinum are unusual tumors. We report herein a case of a 52-year-old woman, who was found to have a mediastinal tumor involving both hemithoraces and radiologically showing non-resectable-invasive features to the adjacent vital structures. She had a history of left thoracotomy for mediastinal schwannoma 14 years previously. The patient underwent an exploratory thoracotomy following a preoperative misdiagnosis of an ancient schwannoma. Complete removal of the tumor was accomplished through a right posterolateral thoracotomy with a subsequent histological diagnosis of a recurrent low-grade liposarcoma. A resectable liposarcoma should be considered in the differential diagnosis of a mediastinal tumor, although radiologically, the tumor presents with invasive features.

Diagnostic Errors↗
PubMed2001

Implantation metastasis caused by fine needle aspiration biopsy following curative resection of stage IB non-small cell lung cancer.

Fine needle aspiration is a useful procedure in the diagnosis of lung cancer, however controversy still remains as to whether it should be employed particularly in patients with operable lung cancer. We report herein a case of metastatic tumor at the site of transthoracic needle biopsy following a curative resection in a patient with stage IB bronchogenic carcinoma. The patient was managed with aggressive chest wall resection and subsequent musculocutaneus flap transposition, however he died 11 months after the initial operation. The tumor implantation risk and the related complications should be considered in patients with operable bronchogenic carcinoma undergoing a tranthoracic needle aspiration biopsy.

Aged↗
PubMed2001

A family-based strategy to identify genes for diabetic nephropathy.

Diabetic nephropathy (DN) clusters in families and specific ethnic groups, suggesting a genetic basis of disease transmission. Identification of DN susceptibility loci should reveal new therapeutic targets but requires accurate phenotyping. A powerful family-based strategy, which is novel to the pursuit of nephropathy genes in type 2 diabetes, is being used to collect a sample for candidate gene and genome scan analyses. Sib pairs that include DN index cases plus (1) sibs concordant for type 2 diabetes and DN (affected sib pairs [ASPs]) and (2) sibs concordant for type 2 diabetes but discordant for DN (discordant sib pairs [DSPs]) are targeted specifically for recruitment. Type 2 diabetes and DN phenotype criteria for index cases include diabetes onset after 38 years of age, duration 10 years or longer, no initial insulin treatment, diabetic retinopathy, end-stage renal disease (ESRD), and history of nephrotic proteinuria. ESRD patients were screened by questionnaire and medical record review (n = 2114). Of 666 patients with ESRD secondary to DN, 227 had a family history of ESRD, 150 had a living diabetic sib, and 124 families were enrolled. Sixty-five families, with 86 diabetic relative pairs (69 sibs, 17 children), have been completely phenotyped. If nephropathy in diabetic sibs is defined as albuminuria greater than 0.3 g/24 h, 31 ASPs and 26 DSPs (diabetic sib with albuminuria <0.3 g/24 h) were identified. Applying more stringent criteria, only 12 ASPs (sib with diabetes >10 years, diabetic retinopathy, and nephrotic proteinuria) and 9 DSPs (sib with diabetes >10 years and normal urine albumin excretion) were identified. Extrapolating from the number of subjects recruited using stringent phenotyping criteria, nearly 10,000 ESRD patients are required for screening to achieve adequate statistical power for linkage analysis (80% power to detect locus-specific relative risk of 2.2 at a lod score of 3.0). Careful phenotyping requires a large recruitment effort but is necessary to reduce population heterogeneity, a strategy that increases the likelihood of identifying DN loci.

Age of Onset↗
PubMed2001

Application of western blotting procedure for the immunodiagnosis of visceral larva migrans in mice by using excretory/secretory antigens.

A Western blotting procedure with excretory/secretory antigens from Toxocara canis larvae was developed for immunodiagnosis of visceral larva migrans in mice. In this study, eighty Swiss albino mice were allotted into two groups of 40 each as control and experimental groups, and T. canis ova containing infective larvae were given to mice in the latter group to form visceral larva migrans. Blood samples were taken from 5 infected and 5 control mice on days 25, 30, 35, 40, 45, 50, 55, and 60 after infection. After bleeding, the mice were necropsied. Slides were prepared from their brain tissues and examined for visceral larva migrans. Following this procedure, their guts were also examined for intestinal parasites. Protein bands of excretory/secretory antigens of 2nd stage larvae of Toxocara canis were determined by using SDS-PAGE. Sera from the mice were tested by Western blotting and results were compared to the protein bands obtained by SDS-PAGE to determine specific bands. Specific protein bands for visceral larva migrans were determined as 24, 28, and 48 kDa according to our test results.

Animals↗
PubMed2000

Transdermal drug delivery using electroporation. I. Factors influencing in vitro delivery of terazosin hydrochloride in hairless rats.

The use of electroporation pulses as a physical means of enhancing the permeability of skin to deliver drugs is in the early stages of development. In this article, a systematic study examining the parameters influencing electroporative transdermal delivery of terazosin hydrochloride to hairless rat skin are reported. It was found that voltage, pulse length (tau), and number of pulses were the three most important parameters, in that order. For creating a significant enhancement in drug delivery to the skin, without causing any apparent change in its external appearance, it was necessary to deliver five or more exponentially decaying electroporation pulses, at 88 +/- 2.5 V (voltage across the skin), with a decay time constant of 20 ms. Electrodes with larger area could attain the same voltages across the skin with a much lower applied voltage and possessed other advantages with regard to performance of the drug delivery system.

Administration, Cutaneous↗
PubMed2000

Transdermal drug delivery using electroporation. II. Factors influencing skin reversibility in electroporative delivery of terazosin hydrochloride in hairless rats.

A previous study indicated that the parameters governing the performance of electroporative delivery to the skin, are voltage, pulse length, number of pulses and electrode area.1 This article describes a study in which the reversibility of the electroporation technique is evaluated with in vitro methods. The skin's reversal from an enhanced permeation mode as a result of electroporation to the base level was used as an index to understand the mechanism of drug delivery and also as a preliminary indicator of safety. Maximum delivery of the model drug, terazosin hydrochloride, occurred during the pulsing. Electroporative delivery with a wire electrode (small-area electrode, 0.56 cm(2)) using 20 pulses at U(skin,0) 88 V, and pulse length 20 ms, did not cause any damage to the skin. Increasing the pulse length to 60 ms, while keeping the rest of the parameters fixed, caused a visible change in the external appearance of the skin. However, with the use of a spiral electrode (large-area electrode, 2.74 cm(2)) at 60-ms pulse length, there was minimal damage to the skin. This may be attributed to the more uniform flow of current over the whole skin area. The large-area electrode required a smaller electrode voltage, U(electrode,0) for any given U(skin,0) and also delivered nearly double the instantaneous power density compared with the small-area electrode. These findings indicate that using shorter pulses and large-area electrodes is a safer technique than large pulses and small-area electrodes when electroporation is used to enhance skin's permeability for drug delivery.

Administration, Cutaneous↗
PubMed2000

Staphylococcal pyomyositis in a patient with non-Hodgkin's lymphoma.

Pyomyositis is a rare disease, encountered mainly in tropical climates. The diagnosis of this entity is difficult, if not misdiagnosed, because of its rarity and its subacute presentation. We report of a 42-year-old man, in whom pyomyositis developed while he was receiving the standard chemotherapy for T-cell non-Hodgkin's lymphoma (NHL). Three months following splenectomy, multiple abscesses occurred in the muscles of both thighs while the patient was receiving the third course of the CHOP regimen. A purulent exudate was aspirated from the abscesses under computed tomographic guidance. Coagulase-positive Staphylococcus aureus was cultured in the aspirate. Pyomyositis was completely resolved following the surgical drainage and the antistaphylococcal antibiotic treatment. This patient has shown that immunosuppression due to splenectomy, NHL, and chemotherapy, especially when using steroids, could be risk factors for pyomyositis in nontropical or semitropical countries.

Adult↗
PubMed2000

Changing patterns of lung cancer; (3/4 in.) 1.9 cm; still a safe length for bronchial resection margin?

BACKGROUND: Surgical resection is the best treatment modality in non-small cell lung cancer (NSCLC). As a guideline, it is suggested that at least a bronchial resection margin of 1.9 cm from the macroscopic tumor might provide a tumor-free margin in lung cancer. In some recent reports, there is great emphasis on the changing histopathological patterns of lung cancer, but no concern for the proximal extension of lung cancer. The aim of this study was to determine the validity of this guideline in the current time. METHODS: Surgically resected specimens of NSCLC cases (n = 70) were examined. The bronchial tree including tumor was dissected and beginning from the edge of the visible tumor, the bronchus were cut into serials in its transverse plane, 5 mm apart from each other. Cut sections were examined for proximal extension of tumor at different levels. RESULTS: Microscopic proximal extension was observed in 24.2% (n = 17/70) of all the cases. Peribronchial extension (n = 9/17) (52.9%) was more predominant compared with bronchial extension (n = 8/17) (47.0%). Squamous cell carcinoma (n = 11/38) (28.9%) showed proximal extension more than adenocarcinoma (n = 5/23) (21.7%). Adenocarcinoma showed more peribronchial extension (n = 4/5) (80.0%) whereas squamous cell carcinoma (n = 7/11) (63.6%) showed more bronchial extension. The farthest extension was 3.0 cm for adenocarcinoma and 2.0 cm for squamous cell carcinoma. Excluding tumor positive specimens beyond 1.5 cm level to the bronchial resection margin, all tumors accounted for 96% of the whole series. CONCLUSIONS: Microscopic proximal extension of lung cancer occurs in 24.2% of NSCLC cases. Squamous cell carcinoma extends more proximally compared with adenocarcinoma in ratio whereas adenocarcinoma extends more in length. A bronchial resection of 1.5 cm in length from the macroscopic tumor will provide clear margins in 93% of NSCLC cases.

Adult↗
PubMed2000

Intercostal arteriovenous hemangioma.

We report a case of a 46-year-old man who presented with a chest wall tumor in the right hemithorax. He underwent thoracotomy to remove the mass, which was found to be an arteriovenous hemangioma arising from the intercostal muscle. Arteriovenous hemangioma is a rare tumor and chest wall is an extremely rare site for this tumor. This tumor should be considered in the differential diagnosis of the chest wall tumors. Complete surgical excision offers the best treatment.

Biopsy↗
PubMed2000

[Pelvic ganglioneuroma. Case report].

Ganglioneuroma is a neurogenic tumor originating from autonomic ganglia. It most commonly occurs in patients younger than 20 years with a slight predominance of females. The pelvic localization is rare. Imaging can lead to diagnosis but it is not specific. The diagnosis can only be confirmed by the pathologic study. The authors report one case of pelvic ganglioneuroma diagnosed in an 11-year-old child who also had hypertension and renal failure.

Acute Kidney Injury↗
PubMed2000

[Carotid body tumors: contribution of the various imaging techniques. A report of six cases].

INTRODUCTION: Carotid body tumors are rare hypervascular lesions arising from neural crest paraganglion cells. MATERIALS AND METHODS: We retrospectively analyzed the imaging features of six patients with carotid body tumors to precise their imaging characteristics in order to find specific signs and elaborate a strategy for diagnosis. RESULTS: Imaging features detect the vascular nature of these tumors of the carotid space causing characteristic widening of the carotid bifurcation. Two patients had multiple (two or more) localizations and one had a family history of glomus tumor. CONCLUSION: MRI with MRA is considered as the gold standard imaging technique for the evaluation of glomus tumors as it allows a multiplanar approach which is important in the preoperative study.

Adult↗
PubMed1999

Beta 1 integrin- and proteoglycan-mediated stimulation of T lymphoma cell adhesion and mitogen-activated protein kinase signaling by thrombospondin-1 and thrombospondin-1 peptides.

Cell-cell and cell-matrix interactions play important regulatory roles in lymphocyte homeostasis. Thrombospondin-1 (TSP1) is a matricellular protein that differentially promotes the adhesion of resting and activated T cells. In this work, we show that adhesion of Jurkat T cells on substrates coated with TSP1 or TSP1-derived peptides is mediated by beta 1 integrins, CD47, and heparan sulfate proteoglycans. Interactions with TSP1 or TSP1 peptides stimulated CD3-induced Ras activation and tyrosine phosphorylation of several T cell proteins. The signals from TSP1 and its derived peptides differentially synergized with activation of the TCR to induce phosphorylation of linker for activation of T cells (LAT) and extracellular signal-regulated kinase (ERK) 1/2, c-Jun N-terminal kinase, and p38 kinases. The phosphorylation of ERK in the presence of full-length TSP1 was transient and dependent on a beta 1 integrin receptor. Interestingly, peptides derived from the type 1 repeats of TSP1 and a CD47-binding peptide from the carboxyl-terminal domain of TSP1 also stimulated mitogen-activated protein (MAP) kinase phosphorylation. Moreover, the TSP1 heparin-binding peptide synergized with Ab-ligated TCR to transduce signals to the nucleus, detected by activation of AP-1- and Elk-dependent transcription. This TSP1 peptide-dependent activation of AP-1 was inhibited by both heparin and the MAP/ERK kinase inhibitor PD98059, providing a functional link between adhesion molecule interaction and nuclear transactivation events via the MAP kinase pathways. These findings have implications for the role of extracellular TSP1 and TSP1 fragments in the regulation of T cell function during hemostasis, wound repair, and other inflammatory responses.

Amino Acid Sequence↗
PubMed1999

The prevalence of coccidian species in sheep in Kars Province of Turkey.

Coccidia were detected in the faeces of 556 out of 592 sheep (93.9%) in sheep in Kars province. The prevalence of coccidiosis was significantly higher (p < 0.01) in young (97.9%) and immature sheep (96.6%) than in adult sheep (90.2%). Mixed infections were widespread (71.5%). Ten species of Eimeria were recognized. These species (and their prevalences) were: Eimeria ovinoidalis (47.7%), E. bakuensis (E. ovina) (46.6%), E. parva (37.1%), E. granulosa (27.7%), E. ahsata (23.4%), E. pallida (23.2%), E. faurei (15.1%), E. intricata (13.9%), E. crandallis (13.7%) and E. punctata (2.3%). Eimeria punctata is reported in sheep from Turkey for the first time. The mean oocyst count from infected animals was 3451 +/- 409 opg (range 50-117,600). The mean was higher (9529 +/- 502) in young sheep. Differences in the counts from young, immature and adult sheep were statistically significant (p < 0.01). However, no clinical cases of coccidiosis were encountered.

Age Factors↗
PubMed1999

A combined method for estimating ventilatory threshold.

BACKGROUND: The aims of this study were to compare two new methods (Dmax and CUSUM) for determination of the ventilatory threshold and to examine the consequences of estimation by application of these methods in combination. METHODS EXPERIMENTAL DESIGN: a comparative design was used. SETTING: the study was performed in the Exercise Physiology Laboratory in the Faculty of Medicine, Selçuk University. PARTICIPANTS: thirty-two untrained males (20.6 +/- 1.2 yrs) performed an incremental exercise test on a cycle ergometer. INTERVENTIONS: there is no intervention. MEASURES: ventilatory and gas exchange variables were measured breath-by-breath. The ventilatory thresholds were detected by conventional linear regression, CUSUM, Dmax and combined CUSUM-Dmax methods. RESULTS: The ventilatory thresholds determined by Dmax method gave the highest r-values compared to the criterion method. There was no statistical difference between thresholds determined by all methods or by the same method using different variables. Ventilatory thresholds could not be determined by the conventional linear regression method in three subjects but were determined in all subjects by the other three methods. CONCLUSIONS: Although all methods presented in this study can be used in the determination of ventilatory threshold, the Dmax method was found to be the most valid one. When using the CUSUM method, combining it with the Dmax method increases the validity of the measurement.

Adult↗
PubMed1998

Drug targeting using low density lipoprotein (LDL): physicochemical factors affecting drug loading into LDL particles.

Low density lipoprotein (LDL) has been found suitable as a targeting carrier for cytotoxic drugs. However, higher drug loading into LDL particles without disrupting their native integrity remains a major obstacle. The purpose of this study is to investigate the different physicochemical factors that may affect drug loading and to characterize LDL-drug conjugates. Doxorubicin (Dox) and 3', 5'-O-dipalmitoyl-5-iodo-2'-deoxyuridine (dpIUdR) were used as reference cytotoxic drugs. Drugs were loaded into LDL particles using the dry film method with or without surfactants, liposomal and the direct addition method. The effects of incubation temperature, time and stoichiometry of LDL-drug conjugates on drug loading were investigated. The LDL-drug conjugates were evaluated for their stability and characterized by differential scanning calorimetry (DSC), denatured gel (SDS-PAGE), and electron microscopy (EM). We have suitably incorporated 45+/-10 Dox and 150+/-25 dpIUdR molecules/LDL particle. A seven-fold increase in Dox incorporation was achieved with the liposomal preparation compared to the dry film method. A 4- to 6-h incubation at 37 degreesC was suitable to restore the native structure of LDL particles. No apo B fragmentation of LDL particles was noted on denatured gel. DSC studies showed no change in the Tm of the LDL and the LDL-drug conjugates. An increase in particle size of LDL-dpIUdR, not LDL-Dox was observed in EM compared to the native LDL which may be related to higher incorporation of dpIUdR. The results indicate that physicochemical factors significantly affect drug loading efficiency and may need to be considered to optimize drug incorporation into LDL particles.

Chromatography, High Pressure Liquid↗
PubMed1998

Transdermal delivery of cyclosporin-A using electroporation.

Topical delivery of cyclosporin A (CSA) is desirable for treating psoriasis, but it is hindered by the barrier property of stratum corneum, and the physicochemical properties of CSA. Attempts to deliver CSA from a solution prepared in 40% ethanol (EtOH) is phosphate buffered saline (PBS) using iontophoresis did not result in any significant increase in drug delivery, compared to passive. However, the use of electroporation pulses as a physical penetration enhancer enabled delivery of a significant amount of CSA. Single pulse electroporation study indicated that the amount of EtOH delivered across the skin increased as the applied electrode voltage (Uelectrode) was increased. However, it did not translate into a proportional increase in the delivery of CSA and only a three to four times increase, compared to passive delivery, was seen with the single purse electroporation. The drug contact duration had a varying effect in the efficiency of transdermal delivery of CSA. Four hour contact duration was chosen for the multiple pulse study. Use of multiple pulses (25 pulses, 10 ms each) at Uelectrode 200 V resulted in a sixty-fold increase, compared to passive, in the delivery of CSA to the skin. Transdermally delivered CSA was mostly bound to the skin and only a small amount was seen to cross the full skin into the receiver compartment. In a study of solvent transport, the flux of water was up to three times larger than that of EtOH after electroporation.

Administration, Cutaneous↗