Two cases of Stevens-Johnson syndrome: toxic epidermal necrolysis possibly induced by amifostine during radiotherapy.
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Biomedical subjects
Publications and source records attributed to S Sahin.
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Proper placement of implants in the posterior maxillary region with poor bone density is essential to obtain long-term success. In this article, the fabrication of a bilaminar dual-purpose stent that facilitates ease in implant placement with improved verification of implant positioning is described. The outer lamina is designed for use in the computed tomography evaluation, using radiopaque markers. The verification of implant alignment and positioning, according to the determined prosthesis, is also performed with this template after modifying it for surgery. The inner lamina is designed to accept 2 removable surgical acrylic resin stents with different guide channels that avoids the risk of surgical malpractice.
BACKGROUND: Intrathecal (IT) opioid and local anesthetic combinations are popular for labor analgesia because of rapid, effective pain relief, but the duration of analgesia is limited. This study was undertaken to determine whether the addition of clonidine and neostigmine to IT bupivacaine-fentanyl would increase the duration of analgesia without increasing side effects for patients in labor. METHODS: Forty-five healthy parturients in active labor were randomized to receive a 2-ml IT dose of one of the following dextrose-containing solutions using the combined spinal-epidural technique: (1) bupivacaine 2.5 mg and fentanyl 25 microg (BF); (2) BF plus clonidine 30 microg (BFC); or (3) BFC plus neostigmine 10 microg (BFCN). Pain, sensory levels, motor block, side effects, maternal vital signs, and fetal heart rate were systematically assessed. RESULTS: Patients administered BFCN had significantly longer analgesia (165+/-32 min) than those who received BF (90+/-21 min; P<0.001) or BFC (123+/-21 min; P<0.001). Pain scores, block characteristics, maternal vital signs, Apgar scores, maternal satisfaction, and side effects were similar among groups except for nausea, which was significantly greater in the BFCN group (P<0.05 as compared with BFC). CONCLUSIONS: The addition of clonidine and neostigmine significantly increased the duration of analgesia from IT bupivacaine-fentanyl during labor, but neostigmine caused more nausea. Although serious side effects were not observed in this study, safety must be further addressed before the routine use of multiple IT drugs is advocated.
Diazepam, a drug of high intrinsic clearance, was studied in the in situ rat liver dually perfused with Krebs-bicarbonate buffer containing human serum albumin (HSA; 0-1%) and unlabeled diazepam (1 mg/l) under constant hepatic arterial (3 ml/min) and portal venous (PV; 12 ml/min) flow rates. Events after a unit impulse (using [(14)C]diazepam) and at steady state (using unlabeled diazepam) were evaluated. In the absence of HSA the fractional effluent recovery (F) after hepatic arterial infusion (0.046 +/- 0.013) was about twice that after PV infusion (0.019 +/- 0.006). With HSA present, regardless of input route, F increased as unbound diazepam fraction in perfusate decreased (e.g., for PV, F = 0.58 +/- 0.05 and 0.69 +/- 0.02 for unbound diazepam fraction values of 0.18 +/- 0.01 and 0.037 +/- 0.01 at 0.25% and 1% HSA). The effluent [(14)C]diazepam profile was also dependent upon HSA. On decreasing HSA from 1 to 0.25% the early sharp peak (at 12-20 s) was replaced by a flatter unimodal profile with a later peak (at 60-80 s). Comparison of estimated effective permeability-surface area product to perfusate flow ratios (4.4 for 1% HSA and 21 for 0.25% HSA) indicated a shift from a perfusion rate-limited uptake with 0.25% HSA to one intermediate between permeability and perfusion at 1% HSA. Recognizing that orally absorbed drug enters the liver only via PV and i.v. drug via both vascular routes, this study emphasizes the difference in hepatic extraction of compounds depending on route of input, and the role that alteration in perfusate binding has on hepatic drug disposition.
PURPOSE: An experimental study was performed to evaluate the effect of fetal distress on in utero defecation and clearance of amniotic fluid (AF). METHODS: Sixteen pregnant New Zealand white rabbits underwent laparotomy at 25 days' gestation (full term, 31 to 32 days) as group A (n = 8) and B (n = 8). Uteroplacental ischemia was achieved by constriction of the aorta below the renal arteries to cause fetal distress in group B, whereas sham operation was done in group A. In both groups, 0.1 mL of technetium-99m (99mTc)-HIDA containing 1 mCi of radioactivity was injected into the gluteus muscle of each fetus, which had been exposed through the uterus. Beginning 2 hours after injection, a live fetus was killed every 2 hours for 48 hours in both groups. Tissue samples from the reference organs (lung, heart, stomach, kidney, bladder) and liver, meconium in proximal, mid and distal bowels, AF, and maternal blood were taken. The radioactivity of each sample was determined by a gamma counter and the percentage injected dose (uptake) per gram of tissue (%ID/g) was calculated. The total uptake and mean transit time (MTT) showing intestinal transport were calculated using the linear trapezoidal approximation and extrapolation. The peak concentration (Cmax, %ID/g) and time corresponding to the peak (tmax, h) were obtained. RESULTS: (1) Significant difference was noted between the groups with regard to uteroplacental perfusion pressure and blood pH (51.0+/-2.6 mm Hg; pH, 6.9+/-0.1 in group B; 80.1+/-2.7 mm Hg, pH, 7.3+/-0.1 in group A; P < .05). (2) 99mTc-HIDA was predominantly trapped by the liver and excreted into the gastrointestinal tract and AF in both groups. (3) In liver and bowel, shape of the profile was bimodal because of fetal swallowing and similar in both groups, tmax was the same in both groups, Cmax was lower in group B than in group A, the total uptake was smaller in group B than in group A, and intestinal transport time was similar (44.2 hours in group A and 43.0 hours in group B). In amniotic fluid, shape of the profile was sigmoidal in group B and reached a Cmax value of 11.6% ID/g, whereas unimodal profiles were observed in group A with a Cmax value of 12.6% ID/g; radioactivity was eliminated from the AF with a rate constant of 0.48% ID/g h in group A (AUC, 273% ID/g h); whereas accumulation of radioactivity was noted in group B (AUC, 308% ID/g h). (5) In maternal blood, shape of the profile was sigmoidal in group A with a Cmax value of 2.9% ID/g and unimodal in group B (Cmax, 1.6% ID/g), accumulation of radioactivity was noted in group A (AUC, 93% ID/g h), whereas a rapid decline of radioactivity (k, 0.06% ID/g h) was noted in group B (AUC, 47% ID/g h). CONCLUSIONS: Fetal distress did not affect the intestinal transport dynamics and in utero defecation but impaired the clearance of AF and the passage into the maternal circulation, which was shown by the accumulation of radioactivity in AF only in group B and in maternal blood only in group A without any elimination rate. This finding suggests that meconium-stained AF is not related to meconium passage after fetal distress; rather, it reflects impaired clearance of AF, which already has containing meconium caused by physiological in utero defecation.
STATEMENT OF PROBLEM: The physical and mechanical properties of soft denture liners are influenced by a number of factors. Aging is one factor that has an effect on the characteristics of polymers. The resistance of denture liners to aging can potentially influence the color stability of these liners. PURPOSE: This study attempted to determine the color stability of soft liners by subjecting them to an in vitro accelerated aging test. MATERIAL AND METHODS: Two autopolymerizing and 3 heat polymerizing commercially available soft denture lining materials were tested. Seven sample disks were made of each material according to manufacturers' instructions. Color measurements were recorded before and after the accelerated aging process. Color changes (DeltaE) were calculated by measuring tristimulus values at several wavelengths in the visual spectrum with the use of Commission International de l'Eclairge Lab (CIE-LAB) uniform color scale. RESULTS: Kruskall-Wallis variance analysis and Mann-Whitney U-Wilcoxon rank sum W tests were performed for statistical comparison of the DeltaE values. Ufigel P and Simpa liner materials showed significantly greater color changes than the other tested materials. There were no significant differences in color change among Ufigel L-Molloplast B, Ufigel L-Flexor, and Molloplast B-Flexor liner materials. However, a significant difference in color change was found between Ufigel P and Simpa liners. CONCLUSION: Heat-polymerized soft liners were more color stable than autopolymerized soft liners. No significant differences were found among heat polymerized materials; however, significant differences in color change were found between the 2 autopolymerized liners.
Kindler syndrome is characterized by congenital blister formation, photosensitivity, poikiloderma, and cutaneous atrophy in later life. There are few reports about the ultrastructural features of this syndrome, but still there is no consensus about the basic disease. Here we report a case of Kindler syndrome with ultrastructural findings.
BACKGROUND: Psoralen plus ultraviolet A (PUVA) is considered to be the treatment of choice for subtotal vitiligo; however, it is time consuming and carries certain health risks for both patients and physicians. This study attempts to evaluate the efficacy of the treatment in Turkish vitiligo patients. METHODS: We have performed a retrospective study of 33 patients with vitiligo who received systemic PUVA therapy during the period 1985 to 1997, and have evaluated their response to treatment. RESULTS: Overall, 28 patients (84%) showed some improvement; 12 patients experienced a repigmentation of 51-75% and six patients achieved greater than 75% repigmentation. Face and trunk lesions showed better repigmentation than other areas, whereas hands, feet, perioral, and periorbital areas were generally refractory to treatment. The age of the patient, age at onset of the disease, sex, disease duration, and degree of depigmentation prior to initiation of therapy had no influence on PUVA-induced repigmentation. CONCLUSIONS: The distribution of vitiliginous skin must be taken into consideration before the initiation of PUVA therapy, as the response to treatment varies greatly with different body sites; hands, feet, perioral, and periorbital regions are particularly treatment resistant.
The hepatic distribution kinetics of salicylic acid was determined using a single-pass dual hepatic artery (HA) and portal vein (PV) perfused in situ rat liver preparation. Bolus doses of [14C]salicylic acid and of reference markers ([3H]-water and [14C]-sucrose) were injected in a random order into either the HA or PV and then, after an appropriate interval, into the alternate vessel. The hepatic outflow profile of [14C]salicylic acid displayed a characteristic sharp peak followed by a slower eluting tail, whereas sucrose and water displayed unimodal outflow profiles. The biphasic outflow profile indicates that the hepatic distribution of salicylic acid is not instantaneous but is limited by a permeability barrier. The in situ permeability surface area product for [14C]salicylic acid was 3.35 +/- 0.26 ml/min/g for PV and 7.45 +/- 1. 50 ml/min/g for HA administration. Furthermore, theory dictates that hepatic uptake is influenced by both perfusion and permeability if effective permeability surface area product/blood flow ratio lies between the values of 0.06 and 7.0. Our estimates (3.0 for venous output and 6.7 for arterial input) indicate that hepatic uptake of salicylic acid is dependent on both perfusion and permeability. The volume terms were calculated using two different methods, standard and specific. Regardless of the compound and method, the volume of distribution after arterial administration was larger than that after venous administration. In addition, a volume of distribution approximately twice that of the total aqueous space (i.e., HA, 2.23 +/- 0.13 versus 1.10 +/- 0.07 ml/g; PV, 1.72 +/- 0.16 versus 0.68 +/- 0.04 ml/g) implies that salicylic acid has a significant affinity for hepatic tissue. A similar tissue-to-perfusate partition coefficient associated with HA and PV input (5.40 +/- 0.38 versus 6. 48 +/- 0.56) indicates that affinity of salicylic acid for hepatic tissue is independent of the route of input.
BACKGROUND: The risk of the occurrence of malignant melanoma (MM) in medium-sized (1.5 to 19.9 cm in diameter) congenital melanocytic nevi (CMN) is the subject of controversy. Universally accepted recommendations regarding the management of such lesions have not been made. OBJECTIVE: Our purpose was to assess the risk of MM arising in medium-sized CMN. METHODS: The study included 230 medium-sized CMN in 227 patients, first seen in a private dermatology practice from 1955 to 1996, who were followed up for MM arising within their CMNs. Criteria for entry into the study included (1) a clinically diagnosed medium-sized CMN, (2) minimum follow-up period of 1 year, and (3) a photograph of the lesion in the patient's medical record. RESULTS: No MM occurred in a medium-sized CMN during an average follow-up of 6.7 years (median, 5.8 years) to an average age of 25.5 years (median, 19.1 years). CONCLUSION: The results of this short-term follow-up study do not support the view that there is a clinically significantly increased risk for MM arising in banal-appearing medium-sized CMN or that prophylactic excision of all such lesions is mandatory. Lifelong medical observation seems a reasonable alternative for many medium-sized CMN.
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An axillary block and lateral femoral cutaneous nerve block combination was used in 11 patients with upper-extremity injuries requiring large skin grafts. In our experience, this block combination was highly successful. All but one of the patients obtained excellent pain relief (mean visual analog pain scores, 0.2) that required no narcotic analgesics or sedatives. There were no systemic or neurologic side effects attributed to the local anesthetic drugs. We believe that combining an axillary block and a lateral femoral cutaneous nerve block is a clinically useful and effective technique and an excellent anesthetic alternative for procedures requiring large grafts for the upper extremity.
The liver receives two blood supplies, the portal vein (PV) and hepatic artery (HA). The isolated perfused rat liver preparation (IPRL) is widely used to examine physiological factors affecting the hepatic disposition of compounds, but usually it is perfused via the PV only. In the development of a more physiological dual perfused system, we examined three surgical procedures for HA perfusion--cannulation through the gastroduodenal artery, the aorta, and the celiac artery--using 14C-urea as the reference marker. Similar efflux profiles for 14C-urea were obtained for all three procedures, with a clear difference between HA and PV administration; however, cannulation of blood vessels and isolation of the HA supply were the most reliable with the celiac artery cannulation, making it the preferred procedure.
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Recently described distinct associations of HLA class II genes with ulcerative colitis (UC) suggest a genetic heterogeneity for disease susceptibility. In this study, HLA-DRB alleles of UC patients (n = 59) from Turkey were investigated and compared with healthy controls (n = 244). Using molecular genotyping by polymerase chain reaction (PCR) and sequence-specific oligonucleotide hybridization, we have shown a positive association of UC patients with the HLA-DRB1*1502 allele (10/59 vs. 16/244; P = 0.02; OR: 2.9) and a negative association with the DRB1*13 allele (7/59 vs. 64/244; P = 0.03; OR: 0.38) compared to controls. HLA-DRB1*0701 was significantly increased in perinuclear antineutrophil cytoplasmic antibody (pANCA)-positive UC patients compared to pANCA-negative patients (8/32 vs. 0/27; P = 0.005), whereas DRB1*1502 was observed more frequently in pANCA-negative patients (8/27 vs. 2/32; P = 0.03). These results extended the reported positive association of DRB1*1502 with UC to another population and supported the genetic susceptibility associated with HLA genes for disease development.
The aim of this study was to estimate the specific arterial water space and associated blood flow using statistical moments of the frequency versus time outflow profile, with a model with specific spaces for hepatic arterial (HA) and portal venous (PV) flows in parallel with a common space. Studies were performed in the in situ dual-perfused rat liver (n = 6-10), using Krebs-bicarbonate buffer with constant PV flow (12 ml/min) and various HA flow rates (3-6 ml/min). An impulse input-output technique was employed, varying the route of input, using [14C]urea as the reference indicator. Regardless of flow conditions, the frequency outflow profile after HA input was flatter and broader and the mean transit time longer than after PV input. Excellent recovery of marker was obtained in all cases. Applying the above model, the specific arterial space was estimated to be 9.7 +/- 2.3 of total water space and receives approximately 17% of the HA flow, with the remainder mixing with portal blood in the common space. The estimated total water content of liver (0.67-0.72 ml/g liver) agrees well with that determined by desiccation (0.72 +/- 0.01 ml/g liver).
BACKGROUND: PUVA has been suggested as an alternative treatment modality for resistant, diffuse alopecia areata (AA). However, there are conflicting reports on its efficacy. OBJECTIVE: The aim of this study was to investigate the efficacy of PUVA treatment of AA in a Turkish population. METHODS: Twenty-four patients (15 female and 9 male) suffering from extensive AA for more than 1 year were included in a retrospective study. PUVA was administered to the whole body 3 times a week. Only 75-100% hair regrowth was defined as cosmetically acceptable. RESULTS: Excellent hair regrowth was achieved in 37.5% of the patients. The therapeutic efficiency was not related to age and sex of the patients, duration and extent of the disease (p <0. 05). CONCLUSION: PUVA can be an alternative therapy for patients with extensive AA independently of the duration of disease.
The objective of the present study was to determine the color changes resulting from the aging process in two cold and three hot curing soft liners and two hard liners. Seven samples were fabricated for each material. The initial color measurements were made with a UV-Visible Recording Spectrophotometer. The samples were then placed in an accelerated aging chamber to simulate the aging process. The color of the samples was then measured again with a colorimeter, and the color changes (delta E) were calculated. The critical mark of color change (delta E) has been quantified by the NBS. It was concluded that cold curing soft liners were not color-stable, and that hot curing soft liners and hard liners had similar color durability. These results suggest that colorants used in cold curing soft liners must be reinforced.