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B Teleky

Publications and source records attributed to B Teleky.

At least 37 records · Page 2Linked to original sources
PubMed1997

The diagnostic value of planar and SPET scintimammography in different age groups.

Planar scintimammography (SMM) with 99Tcm-sestamibi (99Tcm-MIBI) has proved to be a useful method in the evaluation of breast lesions. The aim of our study was to determine the diagnostic value of planar and single photon emission tomograpic (SPET) SMM in different age group. We investigated women with breast lesions for which the surgeon recommended biopsy or careful follow-up. Seventy consecutive patients underwent supine planar SMM, while supine SPET was performed in 68 of the patients. Twenty-seven carcinomas in 23 patients and 35 benign lesions in 31 patients were confirmed histologically. In the remaining 16 patients, the findings were classified as benign at follow-up. The carcinomas and benign lesions had a mean (+/- S.D.) diameter of 25 +/- 17 and 17 +/- 11 mm respectively (P < 0.05). A sensitivity/specificity of 67/96% and 88/91% was obtained with the planar and SPET techniques respectively. The accuracy of both techniques was 90%. In patients aged 40 years or less, SPET increased the sensitivity from 50 to 100% (P < 0.01), whereas it decreased the specificity and accuracy from 94 to 81% and 91 to 81% respectively (N.S.). In patients aged 41-50 years, the sensitivity increased from 63 to 100% (P < 0.01), whereas there was a small decrease in specificity and an increase in accuracy (from 91 to 89% and 86 to 91% respectively, N.S.) We conclude that, in younger patients, a negative SPET SMM study indicates the need for careful follow-up rather than biopsy. However, the addition of SPET in supine scintimammography does-not change the overall accuracy significantly.

Adult↗
PubMed1997

Epidermal growth factor attenuates Clostridium difficile toxin A- and B-induced damage of human colonic mucosa.

Epidermal growth factor (EGF) exhibits a cytoprotective effect on gastrointestinal epithelia via a receptor-mediated mechanism. We investigated the effect of EGF on Clostridium difficile toxin A (TxA)- and toxin B (TxB)-induced damage of human colon. Ussing-chambered colonic mucosa was exposed serosally to EGF before and during luminal exposure to TxA and TxB. Resistance was calculated from potential difference and short-circuit current. Epithelial damage was assessed by light microscopy and alteration of F-actin by fluoresceinated phalloidin. Luminal exposure of colonic strips to TxA and TxB caused a time- and dose-dependent decrease in electrical resistance, necrosis and dehiscence of colonocytes, and disruption and condensation of enterocyte F-actin. These effects were inhibited by prior, but not simultaneous, serosal application of EGF (20 nM). Administration of the tyrosine kinase inhibitor genistein (10(-6) M) inhibited the protective effects of EGF. We conclude that EGF protects against TxA and TxB probably by stabilizing the cytoskeleton, the main target of these toxins.

Actins↗
PubMed1997

Effect of growth factors on epithelial restitution of human colonic mucosa in vitro.

BACKGROUND: Epithelial restitution enables resurfacing of epithelial discontinuities by enterocyte migration. This study investigated the effect of basic fibroblast growth factor (bFGF), insulin-like growth factor (IGF-1), and epidermal growth factor (EGF) on restitution of human colonic mucosa in vitro. METHODS: After base-line incubation human colonic mucosal strips, mounted in Ussing chambers, were luminally exposed to 0.5 mM sodium deoxycholate (NaDOC) for 10 min. Thereafter tissues were incubated with buffer alone or luminal buffer containing various concentrations of bFGF, IGF-1, and EGF for 3 h. Resistance (R) was calculated from potential difference (PD) and short-circuit current (Isc). All tissues were processed for light microscopy. Extent of damage was measured by morphometry. RESULTS: Luminal 0.5 mM NaDOC for 10 min caused R to drop by 43% (n = 4; P < 0.05). Compared with controls 50 ng/ml EGF induced an approximately 30% R increase until the end of the experiments (P < 0.05, n = 4, paired). Ten minutes after injury 50.2 +/- 4% of the mucosa was damaged (n = 6), and after 3 h damage was significantly reduced by EGF (17.2 +/- 3% versus 31.7 +/- 4%, 50 ng/ml EGF versus controls) (P < 0.05, n = 6 per group). Histology showed that EGF stimulated enterocyte migration over the basal lamina. Various doses of bFGF and IGF-1 did not impair restitution when compared with controls. CONCLUSION: In contrast to bFGF and IGF-1, EGF was shown to promote epithelial restitution of human colonic mucosa in vitro.

Colon↗
PubMed1996

Effects of extracellular pH on intracellular pH-regulation and growth in a human colon carcinoma cell-line.

Mechanisms of intracellular pH (pHi) regulation seem to be involved in cellular growth and cell division. Little is known about how extracellular acidosis, known to occur in central regions of solid tumors, or alkaline conditions affect pHi regulation in colonic tumors. pHi changes in the colonic adenocarcinoma cell-line SW-620 were recorded by spectrofluorimetric monitoring of the pH-sensitive, fluorescent dye BCECF, and proliferative activity was assessed by [3H]thymidine uptake. Resting pHi in Hepes-buffered solution was 7.53 +/- 0.01 (n = 36). Both 1 mM amiloride and Na(+)-free solution inhibited pHi recovery from acidification and decreased pHi in resting cells. In HCO3-/CO2-buffered media resting pH1 was 7.42 +/- 0.01 (n = 36). Recovery from acidification was Na(+)-dependent, CI(-)-independent, and only partially blocked by 1 mM amiloride. In the presence of amiloride and 200 microM H2DIDS pHi recovery was completely inhibited. In Na(+)-free solution pHi decreased from 7.44 +/- 0.04 to 7.29 +/- 0.03 (n = 6) and no alkalinization was observed in CI(-)-free medium. Addition of 5 microM tributyltin bromide (an anion/OH-exchange ionophore) caused pHi to decrease from 7.43 +/- 0.05 to 7.17 +/- 0.08 (n = 5). The effects of pH0 on steady-state pHi, pHi recovery from acidification and proliferative activity after 48 h were investigated by changing buffer [CO2] and [HCO3-]. In general, increases in pH0 between 6.7 and 7.4 increased pHi recovery, steady-state pHi and growth rates. In summary, SW-620 cells have a resting pHi > 7.4 at 25 degrees C, which is higher than other intestinal cells. Acid extrusion in physiological bicarbonate media is accomplished by a pHi-sensitive Na+/H+ exchanger and a pHi-insensitive Na(+)-HCO3-cotransporter, both of which are operational in control cells at the resting pHi. No evidence for activity of a CI-/HCO3- exchanger was found in these cells, which could account for the high pHi observed and may explain why the cells continue to grow in acidic tumor environments.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1996

Vascular reconstruction for limb salvage in sarcoma of the lower extremity.

OBJECTIVES: To examine the patency and limb-salvage characteristics of vascular reconstruction in patients with sarcomas of the lower extremity who had been treated with limb-preserving resection and to examine patient survival during a long follow-up period. DESIGN: Retrospective cohort study. SETTING: University hospital, tertiary referral center. PATIENTS: From 1984 to 1992, 14 patients underwent limb-preserving resection of sarcomas in the proximal lower extremity, with 20 vascular reconstructions performed. OUTCOME MEASURES: Color Doppler scans documented patency of the vascular reconstructions. Clinical evaluation included functional results in terms of limb movement and quality of life. Local tumor control and systemic recurrence were examined by repeated radiologic examination. Overall survival as well as time and cause of death were assessed. RESULTS: A total of 13 patients had patent vascular grafts, while the venous graft became occluded in 1 patient. Limb function was rated as excellent or good in 9 patients, as fair in 3, as poor in 1, and could not be clinically estimated in 1. Postoperative thrombosis of the venous graft was detected in 3 patients and was effectively managed by thrombectomy in 2. Three patients underwent reoperation because of hematoma or complications caused by local infection. The tumor endoprosthesis had to be replaced in 3 patients. During follow-up periods that ranged from 15 to 132 months (mean, 55 months), 4 patients died. In all of these patients the cause of death was systemic recurrence in the lung. Two additional patients developed pulmonary metastases, but at the time of this report, they were still alive as long as 132 months after operative resection or chemotherapy. No local recurrence was found. CONCLUSION: Limb-preserving resection of sarcoma of the lower extremity can be performed with satisfactory function of the limb maintained, even if it becomes necessary to resect the femoral vessels. Autologous venous graft for vascular reconstruction is the treatment of choice. In spite of the high incidence of metastases, considerable long-term survival is possible.

Adolescent↗
PubMed1996

Epidermal growth factor promotes rapid response to epithelial injury in rabbit duodenum in vitro.

BACKGROUND & AIMS: Growth factors are mainly involved in the regulation of intestinal epithelial barrier function. This study investigated the effect of epidermal growth factor (EGF) and insulin-like growth factor 1 (IGF-1) on epithelial restitution of rabbit duodenum in vitro. METHODS: Rabbit duodenal mucosal strips mounted in an Ussing chamber were luminally exposed to 10 mmol/L HCl for 10 minutes and then incubated with buffer alone or luminal buffer containing various concentrations of EGF and IGF-1 for 3 hours. Resistance was calculated from potential difference and short-circuit current. Damage was assessed by morphometry on H&E-stained sections. RESULTS: HCl caused resistance to decrease from 112 +/- 2 to 51 +/- 4 ohms x cm2 10 minutes after injury (n = 6; P < 0.05). Postinjury treatment with 25 or 50 ng/mL luminal EGF for 3 hours stimulated resistance to recover to 94 +/- 3 and 104 +/- 3 ohms x cm2, respectively, vs. 81 +/- 3 omega x cm2 in controls (P < 0.05). Ten minutes after injury, 62% of the mucosa was damaged; 3 hours after injury, damage was reduced to 24% +/- 1.09% and 10% +/- 1.42% in the 25 and 50 ng/mL EGF group, respectively, vs. 38% +/- 0.93% in controls (n = 6 per group). EGF stimulated enterocyte migration. IGF-1 did not impair epithelial restitution. CONCLUSIONS: EGF, but not IGF-1, promoted epithelial restitution of rabbit duodenum in vitro.

Animals↗
PubMed1996

Laminin stimulates rapid epithelial restitution of rabbit duodenal mucosa in vitro.

BACKGROUND: This study investigated the effect of the basal lamina constituents fibronectin, collagen IV, and laminin on epithelial restitution of rabbit duodenum in vitro. METHODS: Rabbit duodenal mucosal sheets were mounted in Ussing chambers, luminally exposed to 10 mM HCI for 10 min, and incubated with buffer or luminal buffer containing 25-100 micrograms/ml of collagen IV, fibronectin, laminin, or polyclonal antisera directed against these proteins (diluted 1:50-1:20) for 3 h. Resistance was calculated from potential difference and short-circuit current. Mucosal damage was assessed by morphometry on hematoxylin- and eosin-stained sections. RESULTS: Acid exposure caused a 40% drop in resistance (119 +/- 5 versus 71 +/- 5 Ohm.cm2 before versus after injury; P < 0.05, n = 6) and mucosal damage of 58 +/- 4% (n = 6). Three hours after injury resistance was 102 +/- 6, 117 +/- 4, and 48 +/- 5 Ohm.cm2 in the control, laminin, and anti-laminin groups, respectively. Furthermore, 36 +/- 2%, 16 +/- 2%, and 64 +/- 5% of the mucosa was damaged in the control, laminin, and anti-laminin groups, respectively, 3 h after injury (P < 0.05 versus controls). Laminin promoted epithelial wound closure by stimulation of enterocyte migration, which was inhibited by anti-laminin. Fibronectin, collagen IV, anti-fibronectin, and anti-collagen IV did not impair restitution. CONCLUSION: Our results show that laminin promotes electrophysiologic restoration and epithelial restitution of rabbit duodenum in vitro. We therefore suggest that laminin plays an important part in the orchestration of epithelial integrity and barrier function.

Animals↗
PubMed1994

Intersphincteric resection for low rectal tumours.

An abdominoperineal operation is described that extends rectal resection for low tumours into the intersphincteric plane with removal of the internal sphincter. Bowel continuity is restored by coloanal anastomosis. Of 38 patients who underwent surgery since 1984, 34 had low rectal cancer and four carcinoid or large villous adenoma. There was no mortality. Four patients developed local recurrence during a median observation period of 3 years. Continence was satisfactory in all patients. The median daily number of bowel movements during the first months after colostomy closure was 9 but decreased to 3 after 1 year and 1 after 2 years. Anal manometry demonstrated a significant reduction of mean resting pressure from 91.8 to 35.1 cmH2O with no recovery after 2 years (P < 0.0001). Squeeze pressure showed only a transient decrease.

Adult↗
PubMed1994

Alteration of maximum anal resting pressure by digital rectal examination prior to manometry: analysis of agreement between repeat measurements.

To study whether digital examination preceding anal manometry causes significant alteration of maximum resting pressure reading and to quantify the discrepancies, 78 individuals (64 incontinent, 14 controls) were investigated. Recordings of maximum resting pressure were taken before and after digital rectal examination. There was a mean discrepancy of only -1.8 cms H2O between the readings and excellent correlation, but analysis of agreement revealed a bias that tended to be greater with smaller measurements and unacceptable variability between test results. Furthermore, the bias was not related to age, gender, the grade of incontinence, maximum voluntary contraction, functional anal canal length and threshold volume. Digital rectal examination prior to manometry causes unpredictable results especially in patients with lower maximum resting pressures and should strictly be avoided.

Adult↗
PubMed1994

Intracellular pH regulation of human colonic crypt cells.

In order to investigate the regulation of intracellular pH (pHi) in freshly isolated human colonocytes, we have used a newly developed technique for the rapid isolation and covalent attachment of these cells to glass surfaces and microspectrofluorimetric measurement of the pH-sensitive fluorescence of 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF)-loaded specimens in a perfusion chamber (37 degrees C). In N-2-hydroxyethylpiperazine-N'-2-ethanesulphonic-acid-(HEPES)-buffered Ringer solution (HBS) a baseline pHi of 7.35 +/- 0.03 (mean +/- SD; n = 42) was found for human colonocytes and in HBS, NH4Cl-prepulse-induced intracellular acidification in colonocytes is reversed rapidly by the ubiquitous amiloride-sensitive (1 mmol/l) Na+/H+ exchanger. Switching from HBS to HCO(3-)-buffered solution (BBS) led to a transient intracellular acification (7.29 +/- 0.09), followed by a recovery to a final resting pHi of 7.43 +/- 0.03. One-third of the acid extrusion in BBS is amiloridesensitive; the remaining two-thirds are caused by the dihydroderivative of 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (H2DIDS)-sensitive HCO(3-)-dependent mechanisms. The functional activity of an acid-extruding Na+/HCO3- cotransporter in human colonocytes was observed in response to the reintroduction of Na+ into amiloride-containing Na+/Cl(-)-free BBS. In addition, the mechanism leading to alkalinization (7.56 +/- 0.05) in Cl(-)-free BBS was identified as Na(+)-dependent Cl-/HCO3- exchange, by its H2DIDS sensitivity and the specific requirement for Cl- and Na+. The intrinsic buffering capacity (beta i) of the human colonocytes was calculated from pH changes induced by sequential NH4Cl-loading steps during blockage of acid/base transporters.(ABSTRACT TRUNCATED AT 250 WORDS)

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1994

Inhibition of P-glycoprotein-mediated vinblastine transport across HCT-8 intestinal carcinoma monolayers by verapamil, cyclosporine A and SDZ PSC 833 in dependence on extracellular pH.

The ability of the multidrug resistance modifiers R- and R,S-verapamil (VPL), cyclosporine A (CsA) and its non-immunosuppressive derivative SDZ PSC 833 (PSC 833) to inhibit P-glycoprotein (P-gp)-mediated transepithelial flux of tritiated vinblastine was investigated using tight and highly resistant (R > 1,400 omega cm2) monolayer cultures of intestinal adenocarcinoma-derived HCT-8 cells grown on permeable tissue-culture inserts. Apical addition of these chemosensitizers inhibited drug flux (137 pmol h-1 cm-2; range, 133-142 pmol h-1 cm-2) in the basal to apical secretory direction at clinically relevant concentrations, with PSC 833 showing the highest activity, exhibiting inhibition at concentrations as low as 10 ng/ml (9 nM). Acidification of the modulator-containing apical compartment to an extracellular pH (pHo) of 6.8 had no influence on MDR reversal by CsA at 1 microgram/ml (0.9 microM; flux inhibition, 52%) or by PSC 833 at 100 ng/ml (0.09 microM; flux inhibition, 60%), in contrast to R,S- and R-VPL, which showed decreased inhibition and caused less accumulation of vinblastine in HCT-8 cells under this condition (flux inhibition of 35% and 23%, respectively, at pHo 6.8 vs 50% and 43%, respectively, at pHo 7.5). P-gp-mediated rhodamine 123 efflux from dye-loaded single-cell suspensions of HCT-8 cells as measured by flow cytometry was not impeded at pHo 6.8 in comparison with pHo 7.5 in standard medium, but at low pHo the inhibitory activity of R-VPL (29% vs 60% rhodamine 123 efflux inhibition) was diminished significantly, again without a reduction in the effect of PSC 833 (rhodamine 123 flux inhibition, 75%). In conclusion, drug extrusion across polarised monolayers, which offer a relevant model for normal epithelia and tumour border areas, is inhibited by the apical presence of R,S- and R-VPL, CsA and PSC 833 at similar concentrations described for single-cell suspensions, resulting in increased (2.2- to 3.7-fold) intracellular drug accumulation. Functional apical P-gp expression, the absence of paracellular leakage and modulator-sensitive rhodamine 123 efflux in single HCT-8 cells indicate a P-gp-mediated transcellular efflux in HCT-8 monolayers. In addition to its high MDR-reversing capacity, the inhibitory activity of PSC 833 is not affected by acidic extracellular conditions, which reduce the VPL-induced drug retention significantly. As far as MDR contributes to the overall cellular drug resistance of solid tumours with hypoxic and acidic microenvironments, PSC 833 holds the greatest promise for clinical reversal of unresponsiveness to the respective group of chemotherapeutics.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

Treatment of Candida albicans fungaemia with fluconazole.

Sixty-five patients with Candida albicans fungaemia, admitted to intensive care units, were treated intravenously with fluconazole. All patients had at least one blood culture which was positive for C. albicans. The first group of 34 consecutive patients received fluconazole at a dose of 5 mg/kg bodyweight/day and the subsequent 31 patients received 10 mg/kg/day. Thirty patients in each group were evaluated. The clinical response rate was 60% in the 5 mg/kg once daily group and 83% in the group which received 10 mg/kg/day. Eradication of C. albicans from the blood was achieved in all but two patients in the 5 mg/kg group and in all patients in the 10 mg/kg group. As regards other sites of infection, eradication was achieved in only nine of 25 cases from the 5 mg/kg group and in 11 of 23 cases from the 10 mg/kg group. Death related to fungal infection occurred in eight patients receiving 5 mg/kg/day and in one patient receiving 10 mg/kg/day. Fluconazole was reasonably well tolerated. Raised concentrations of liver enzymes were observed in 14 patients. Other adverse effects were fatigue, nausea, gastric pain, sleepiness and epileptic seizure. In conclusion, fluconazole at a dose of 10 mg/kg/day would seem to be an effective and safe drug for the management of C. albicans fungaemia.

Adolescent↗
PubMed1993

[Determinants of pouch function after continence-preserving proctocolectomy].

A prospective study was undertaken in 17 patients undergoing restorative proctocolectomy for ulcerative colitis (13 patients) or familial adenomatous polyposis (4 patients) to determine relationship between pre- and postoperative anal sphincter function, pouch characteristics and functional results. Postoperatively all manometric parameters were significantly reduced and remained so permanently. Only squeeze pressure rose to normal values again. The most important factor for a favourable functional outcome was pouch volume. A capacious reservoir was associated with a low stool frequency, low risk of incontinence and general success of the operation, as assessed subjectively. Perianal soreness with considerable skin problems occurred frequently when resting and squeeze pressures were markedly reduced postoperatively.

Adenomatous Polyposis Coli↗
PubMed1992

The prognosis of rectal carcinoid tumours.

Carcinoid tumours of the rectum are very rare, and they may present special therapeutic problems for the surgeon. Tumour size and muscle layer invasion are the two most important factors predicting their malignant potential. A series of 20 patients with carcinoid tumours of the rectum were reviewed. 16 tumours less than 2 cm in diameter had neither muscle layer invasion nor lymph node metastases, with the exception of one tumour. Four patients with tumours larger than 2 cm died from metastatic carcinoid. In order to plan operative management endoluminal ultrasound should be performed preoperatively. Rectal carcinoid tumours should be treated like carcinomas of the rectum if they are 2 cm or more in diameter or if they demonstrate muscularis propria invasion independent of tumour size.

Adult↗
PubMed1992

Colorectal cancer involving the urinary tract.

The survival rate among patients with colorectal cancer classified as Dukes' B or C who underwent extended resection due to infiltration of neighboring structures is significantly lower than among patients in the same Dukes' stage without infiltration of adjacent structures. Seventy-one patients with rectosigmoid cancer (37 primary and 34 recurrent tumors) involving the urogenital tract were retrospectively analyzed. Patients with primary tumors had a markedly higher mean survival rate after radical surgery (60.7 months) than after palliative procedures (28.2 months), while no such difference was seen among patients with recurrent tumors (17.6 or 14.1 months, respectively). From the urologic point of view, radical intervention is mandatory in cases of primary rectosigmoid carcinoma involving the urogenital tract. Aggressive surgery for recurrent tumors appears questionable, however; in these cases, priority should be given to improving the quality of life, recommending palliative surgery as the preferable approach.

Adult↗
PubMed1991

[Surgical therapy of proximal bile duct cancer].

During the past 13 years a total of 60 patients (33 male, 27 female, median age 64.8 years) were operated upon and 21 of these patients underwent resection with a resectability rate of 35%. The remaining 39 patients had a palliative procedure. In 7 patients some form of bypass procedure was performed. 25 patients underwent some form of drainage procedure and in 7 patients only an explorative laparotomy was undertaken. Patients having resection surgery had a postoperative complication rate of 29% and there were 2 postoperative deaths (9.5%). The complication rate in the palliation group was 38%. The mean survival time in patients operated on with surgical resection was 34.1 months, palliative procedures 4.8 months and in patients with nonresectable tumors 3.6 months. In the resection group (n = 21) curative resection (= R0-resection) was performed in 14 patients, whereas in 7 patients there was a histologically invasion of the bile duct (= R1-resection). The mean survival time in the R0-group was 45.7 months and 11.8 months in the R1-group (Breslow p less than 0.0098, Mantel-Cox p less than 0.0070). We conclude that radical surgical resection offers the best possibility of prolonged survival with a good quality of life in patients with hilar cancer.

Aged↗
PubMed1991

[Therapy and the natural course of axillary vein thrombosis--review of 765 patients and analysis of our personal patient sample].

UNLABELLED: Thrombosis of the axillary vein is a rare event. The incidence of 0.5, -1.5% of all venous thromboses makes comparative studies concerning therapy in a single center impossible. 15 own patients and 750 patients with axillary vein thrombosis collected from literature were studied, to compare the different therapeutic modalities. 36% received no therapy (NV), 15% anticoagulation (AG: heparin, warfarin, coumarins), 18% thrombolytic therapy (TL streptokinase, urokinase, locally and systemic) and 31% were treated by surgery (OP). Mean follow up was 32 months in NV, AG: 16, 3, TL: 35, OP: 38 months. RESULTS: NV; No complaints: 12%, PTS I: 29%, PTS II: 25%, PTS III: 33%. CONCLUSION: Untreated axillary vein thrombosis leads to functional disability of the affected extremity in one third. AG reduces this rate to 25%. After surgery and thrombolytic therapy a severe PTS is found only in 12% and 13.7% respectively. Loss of extremity was found in 5 cases (0.6%). A mechanic factor seems to be important in thrombogenesis. Rapid restitution of venous backflow and promotion of collateralisation is important to avoid disability of the patient. The low difference between AG and OP is pointed out indicating that invasive surgery should be restricted to special cases.

Adult↗