Effect of Iron Content on Corrosion Properties of Pure Titanium as Grain Refiner

Microstructures and corrosion properties of pure titanium were characterized when iron was used as a grain refiner. The added Fe element acted as a strong grain refiner for pure titanium by forming β Ti phase at grain boundaries, and 0.15 wt% Fe was revealed to be a sufficient amount to make the grain size of pure titanium below 20 μm, which was the requirement for the desired titanium cathode. However, corrosion resistance was decreased with the Fe amount added. From the open circuit potential (OCP) results, it was obvious that the TiO₂ stability against the reducing acid environment was deteriorated with the Fe amount, which seemed to be the main reason for the decreased corrosion resistance. Electrochemical impedance spectroscopy (EIS) results showed that both the decrease in the compact oxide film’s resistance (R_b) and the appearance of the outer porous film occurred as a result of the dissolution of the TiO₂ layer, whose phenomena became more apparent as more Fe was added.

Osteoconductivity of Porous Titanium Structure on Implants in Osteoporosis

In compromised bone conditions such as osteoporosis, developments of the implant surface are necessary to secure the stability of implants. This study investigated the effect of the surface porous titanium structure (PS) on the osseointegration of implants in osteoporotic bone. Bilateral ovariectomy (OVX) was performed in 4 female beagle dogs to induce osteoporosis for 32 wk. Success of induction was based on the evaluation of bone mineral density by Hounsfield units (HU) in computed tomography images. Posterior teeth in both mandibles were extracted 1 wk after OVX, and a total of 30 implants (15 implants in each group) were placed after 32 wk of osteoporosis induction. The control group implant underwent resorbable blast media (RBM) surface treatment, whereas the test group underwent RBM surface treatment in the coronal two-thirds and a PS added to the apical 3-mm portion. HU values in the mandibular trabecular bone, lumbar, and femoral head significantly decreased 32 wk after OVX, confirming osteoporotic condition after induction. Resonance frequency analysis and removal torque test showed comparable values between the 2 groups at 4 wk after implant placement. The surface topography of the implant after removal showed hard tissue integration at the PS in the test group. Bone-to-implant contact length was greater in the apical portion of the test group, although statistical significance was not found between the groups. Interthread bone area in the apical portion of the test group showed a significant increase compared to the control group (control: 0.059 ± 0.041 mm², test: 0.121 ± 0.060 mm², P = 0.028) with the histological feature of bone ingrowth at the PS. The findings of the study demonstrated that the surface PS could improve osteoconductivity in the osteoporotic trabecular bone by bone ingrowth at the pore space, thereby enhancing the osseointegration and stability of the implants.

Demetylation of the sex-determining region Y gene promoter and incidence of disorder of sex development in cloned dog males

Canine cloning is occasionally accompanied by abnormal sexual development. Some male donor cells produce cloned pups with female external genitalia and complete male gonadal dysgenesis, which is classified as an XY disorder of sex development (XY DSD). In this study, we examine the potential of 5-aza-2'-deoxycytidine (5-aza-dC), a DNA methyltransferase inhibitor, to reduce the phenotypic abnormality XY DSD in somatic cell nuclear transfer (SCNT)- derived pups. We used a 9-year-old normal male German Shepherd dog as a cell donor. Donor cells were treated with 10 nM 5-aza-dC for 4 days before being used for SCNT. At the same stage of cell development, significantly lower levels of DNA methylation of the sex-determining region Y (SRY) promoter was observed in the treated donor cells compared to that in the untreated cells (95.2% versus 53.3% on day 4 for the control and treated groups, respectively). No significant differences were observed in the control or treatment groups concerning fusion rate, pregnancy rate (30 days or entire period), the number of pups, or the incidence of XY DSD. However, more XY DSD dogs were observed in the control group (31.25%) than in the treatment group (14.29%). Hypermethylation of the SRY promoter was observed in the XY DSD cloned pups in both the treatment (84.8%) and control groups (91.1 ± 1.4%) compared to the methylation level in the phenotypically normal male pups of the treatment (23.2 ± 20.9%) and control groups (39.1 ± 20.1%). These results suggest that 5-aza-dC treatment of donor cells can reduce the methylation level of the SRY promoter in donor cells, and thus, 5-aza-dC is advantageous for reducing the incidence of XY DSD in canine cloning.

Variation of Mechanical Characteristics of Polyurethane Foam: Effect of Test Method

Polyurethane foam (PUF), a representative insulation material, not only prevents heat conduction but can also support a load. Particular interest in rigid PUF proliferated over the past several years in fields where extreme environments are applied. A closed-cell structure which forms the interior of rigid PUF serves to maximize the utilization of these polymeric foams. Rigid PUF is more sensitive to external conditions such as temperature or restraint than other structural materials such as steel. Depending on the market trends in which utilization of a cryogenic environment is expanding, the tendency of material behavior resulting from the binding effect also needs to be investigated. However, most conventional compression test method standards applicable to rigid PUF do not adequately reflect the restraints. Therefore, this study proposes a method for evaluating the mechanical performance of materials in a more reliable manner than that of conventional tests. Experimental observation and analysis validated this compression evaluation method in which constraints are considered. Consequently, the compressive strength of rigid PUF compared to the results of the conventional test showed a difference of up to 0.47 MPa (approximately 23%) at cryogenic temperatures. This result suggests that there are important factors to consider when assessing performance from a material perspective in an environment where rigid PUF insulation is utilized. It is believed that the test methods newly proposed in this study will provide an experimental framework that can be applied to the evaluation criteria of material properties and reflected in structural design.

Analysis of the mechanical properties of polymer materials considering lateral confinement effects

The mechanical properties of polyurethane foam (PUF) and glass fiber-reinforced PUF (R-PUF), which are widely used in various fields, were investigated considering the influence of lateral confinement. PUF and R-PUF – representative polymeric foams with a porous structure – are suitable for severe environments (e.g. the cryogenic field) because they have an excellent adiabatic function and load-bearing capability. However, when PUF and R-PUF are used in actual structures, the mechanical performance of the foam materials may change depending on the conditions. Assuming that a compressive load acts on these polymeric foams in a confined space, analysis of the material properties resulting from the confining pressure of the adjacent structures is necessary. Therefore, in this study, a comparison and evaluation of the mechanical behavior of PUF and R-PUF were performed with regard to the constraint. The results suggest that it is possible to provide an experimental basis for measuring the strength performance for the application of insulation in a confined space.

Treatment of comminuted proximal humeral fractures using locking plate with strut allograft

BACKGROUND

This study compared the radiologic outcome of fixation using locking plate only with fixation using locking plate with an endosteal strut allograft in the treatment of comminuted proximal humeral fracture.

METHODS

Among 52 patients with comminuted proximal humeral fracture, 32 patients underwent fixation with locking plate only, and 20 patients underwent fixation using locking plate with an endosteal strut allograft. The strut allograft was inserted into the intramedullary cavity of the humerus to support the humeral head and fixed with the locking plate. Immediate postoperative radiologic findings were compared with those of 6 months or more after the surgery, and loss of anatomic fixation was defined if the varus malalignment of neck-shaft angle (NSA) was more than 5° or if the change of humeral head height (HHH) was more than 3 mm.

RESULTS

In the locking plate-only group, 22 of 32 patients (69%) showed the change in NSA of more than 5°, with an average of 10.2°. The HHH change in 20 patients (62.5%) was more than 3 mm, with an average of 4 mm. Among 20 patients who underwent locking plate with the endosteal strut allograft, the average NSA and HHH change was 3° and 1 mm, respectively. Varus malalignment was evident in 2 patients (10%). The HHH change was more than 3 mm in 1 patient (5%).

CONCLUSION

Fixation using a locking plate with an endosteal strut allograft can be considered a reasonable option to maintain the anatomic reduction in elderly patients with comminuted proximal humeral fracture.

Clinical and angiographic follow-up of spontaneous isolated superior mesenteric artery dissection

OBJECTIVES

To observe the clinical features and angiographic findings in patients with a spontaneous isolated superior mesenteric artery dissection (SISMAD) and to identify any correlation between them.

METHODS

From a single institution, 32 patients (22 symptomatic patients at presentation; mean age 54years; men 97%) with SISMAD were retrospectively reviewed. All patients were available for clinical follow-up after treatment (conservative, n=28, 88%, open or endovascular superior mesenteric artery (SMA) reconstruction, n=4, 12%), and follow-up CT scans were available in 28 patients (mean 22months, range 1-80months).

RESULTS

We found a positive correlation between pain severity and dissection length (p=0.03, rho=0.50, Spearman's partial correlation analysis). After conservative treatment, only one patient (3%) required bowel resection, and there was no difference in outcome between patients who were treated with anticoagulation or anti-platelet therapy and those who were not (p=1.00, Fisher's exact test). No patients had progression of their lesion on the follow-up CT angiography.

CONCLUSIONS

In SISMAD patients, dissection length is positively associated with more severe clinical symptoms. After conservative treatment, we observed a benign clinical course and no CT progression of the dissection, even without anticoagulation or anti-platelet therapy. Based on our observation, patients with SISMAD can be treated conservatively without anticoagulation therapy.

Preparation of 153Sm-chitosan complex for radiation synovectomy

A samarium 153-chitosan complex was prepared by simply mixing acidic solutions of chitosan and (153)SmCl(3). When a solution of this complex was injected into the knee joints of rabbits, minimal extra-articular leakage was observed. This can be attributed to the rapid change in the pH of the complex solution from acidic to neutral, resulting in the formation of gel followed by the subsequent retention in the administered site. Thus, the complex solution represents a promising candidate for radiation synovectomy.

Malignant obstruction of gastric outlet and duodenum: palliation with flexible covered metallic stents

PURPOSE

To assess the usefulness of flexible covered metallic stents in the palliation of malignant obstruction of the gastric outlet and duodenum.

MATERIALS AND METHODS

Twenty-four consecutive patients with malignant obstruction of the gastric outlet (n = 22) or duodenum (n = 2) underwent palliative treatment with self-expandable flexible covered metallic stents. Fourteen patients had advanced gastric carcinoma at the antrum and/or pylorus, and eight had obstruction at the anastomosis site of previous gastrojejunostomy. Complications and clinical status were investigated during the study period.

RESULTS

The technical success rate was 75% (18 of 24 patients). Twenty-one stents were placed in 18 patients by using an introducer 6 (n = 7) or 8 mm (n = 14) in diameter. The mean follow-up period was 3.4 months (range, 1 week to 9 months). Symptoms improved in 12 (67%) patients after the procedure. There was no change in symptoms in five and a decrease in one. Twelve patients died during the follow-up period (mean survival, 4.3 months). The complication rate was 25% (six of 24 patients), including stent migration (n = 5) and fracture (n = 3).

CONCLUSION

Flexible covered metallic stent placement can be useful for palliation in patients with malignant obstruction of the gastric outlet or duodenum.

Structural and functional alterations of the peritoneum after prolonged exposure to dialysis solutions: role of aminoguanidine

OBJECTIVE

The effect of long-term use of high glucose dialysate on peritoneal structure and function, and its relation with accumulation of advanced glycosylation end-product (AGE) in the peritoneum was investigated in this study.

METHODS

Dialysates with 4.25% glucose were injected into the peritoneal cavity of normal rats for 12 weeks without (PD, n = 7) and with (1 g/L, PD+AG, n = 7) aminoguanidine in their drinking water. Rats not having intraperitoneal (IP) injection served as control (n = 9). After 12 weeks of IP injection, a 2-hour peritoneal equilibration test (PET) was performed using 30 mL 4.25% glucose dialysate. Intraperitoneal volume (IPV), dialysate-to-plasma urea ratio at 2 hours (D/P2), the ratio of dialysate glucose at 2 hours to initial dialysate glucose (D2/D0), and the peritoneal fluid absorption rate (Qa) were evaluated. After the PET, samples of the parietal peritoneum were taken for hematoxylin and eosin (H&E) staining and immunohistochemical staining for AGE.

RESULTS

The IPV and D2/D0 glucose were significantly lower and Qa and D2/P2 urea significantly higher in the PD group than in the control group. Aminoguanidine reversed in part the changes in IPV and D2/P2 urea in the PD group; it had no effect on Qa and D2/D0 glucose. The H&E staining showed a linear mesothelial lining with negligible cells and capillaries in the narrow submesothelial space in the control group. Mesothelial denudation and submesothelial infiltration of monocytes and capillary formation were observed in the PD group. Mesothelial denudation was relatively intact in the PD+AG group compared with the PD group. Submesothelial monocyte infiltration and capillary formation in the PD+AG group were not as prominent as in the PD group. Positive AGE staining was found in the submesothelial space, vascular walls, and endomysium in the PD group, while it was markedly attenuated in PD+AG group and negligible in the control group.

CONCLUSION

Long-term use of high glucose solutions induced peritoneal AGE accumulation and mesothelial denudation, and increased peritoneal permeability and peritoneal fluid absorption rate. Inhibition of peritoneal AGE accumulation prevented those functional and structural damages to the peritoneum.

Malignant esophagogastric junction obstruction: palliative treatment with an antireflux valve stent

The authors assessed the efficacy of an antireflux valve stent in the palliation of malignant esophagogastric junction (EGJ) obstruction after in vitro testing of the stent. Seventeen patients with inoperable malignant EGJ obstruction were treated. Antireflux valves, made of three polyurethane leaflets, were attached to the distal part of the stent to prevent reflux. When the flow rate of normal saline was 100 mL/sec in the forward direction, the valve fully opened at a pressure of 10 mm Hg. When the flow rate of normal saline was 0.35 mL/sec in the backward direction, the valve nearly completely closed at a pressure of 10 mm Hg. Stent placement was successful in all patients without complications. The median dysphagia score decreased significantly, from 3.0 (dysphagia to liquids) to 1.0 (dysphagia to normal solid food) (P < .0005). No patients experienced reflux symptoms. There was one case of stent migration. A valve stent that can prevent major reflux is an effective device for the palliation of malignant EGJ obstruction.

Influence of reduced glutathione on the proliferative response of sulfamethoxazole-specific and sulfamethoxazole-metabolite-specific human CD4+ T-cells

1. Hypersensitivity to the drug sulfamethoxazole (SMX) is thought to be a consequence of bioactivation to the hydroxylamine metabolite (SMX-NHOH) and further oxidation to the ultimate reactive metabolite, nitroso-sulfamethoxazole (SMX-NO). SMX-NO covalently modifies self proteins which in turn might be recognized as neo-antigens by T-cells. The antioxidant glutathione (GSH) is known to protect cells from reactive metabolites by conjugation and subsequent dissociation to SMX-NHOH and/or SMX. 2. To study the reactivity of T-cells to SMX metabolites and their respective role in the generation of drug-specific T-cells, we analysed the effect of GSH on the response of PBMC to SMX and its metabolites SMX-NHOH and SMX-NO. Furthermore, we monitored the proliferative response of drug-specific T-cell clones in the presence or absence of GSH. 3. We found that addition of GSH to peripheral blood mononuclear cells had no effect on the SMX-specific response but enhanced the proliferation to SMX-metabolites. The response of SMX-NO-specific T-cell clones was abrogated when GSH was present during the covalent haptenation of antigen presenting cells (APC). Conversely, SMX-specific T-cell clones gained reactivity through the conversion of SMX-NO to the parent drug by GSH. While GSH had no effect on the initial activation of T-cell clones, it prevented covalent binding to APCs, reduced toxicity and thereby led to proliferation of drug-specific T-cells to non-reactive drug metabolites. 4. Our data support the concept that in allergic individuals T-cells recognize the non-covalently bound parent drug rather than APC covalently modified by SMX-NO.

Diagnostic pitfalls in the cholangiographic diagnosis of choledochoceles: cholangiographic quality and its effect on visualization

BACKGROUND

We wanted to establish reasonable cholangiographic diagnostic criteria by determining the sensitivity of cholangiography in detecting choledochoceles and those factors that could compromise visualization of choledochoceles.

METHODS

Over 4 years, 21 patients (seven male, 14 female; mean age = 67 years) were confirmed as having choledochoceles on endoscopic retrograde cholangiopancreatography (ERCP). Cholangiographic diagnosis was made by following three criteria: a radiolucent halo around the distal common bile duct (CBD), bulbous dilatation of the distal CBD, and the presence of sequential morphologic changes on serial cholangiography. Any two or more combinations of these three criteria were considered enough to diagnose a choledochocele on cholangiography. We compared cholangiographic imaging findings with the ERCP results.

RESULTS

Of 21 patients with choledochoceles, nine (43%) were correctly diagnosed on cholangiography. A radiolucent halo was present in six (28%) patients; four of these cases showed optimal duodenal filling, one showed faint duodenal filling, and one showed poor duodenal filling. The shapes of the distal CBD were bulbous, conelike, and blunt. Morphologic changes such as collapsing and bulging of the choledochocele could be seen in 12 (57%) patients on serial cholangiography. Waists were seen in 11 (52%), pseudowebs in four (19%), and wrinkling of the distal CBD in seven (33%).

CONCLUSION

Cholangiography should be obtained with optimal timing and adequate conditions to diagnose choledochocele correctly.

Measurement of radiation absorbed dose in endovascular Ho-166 brachytherapy using a balloon angio-catheter

The purpose of this study was to estimate the absorbed dose distribution of Ho-166 endovascular beta irradiation using an angio-catheter. The liquid form of Ho-166 was produced at the Korea Atomic Energy Research Institute (KAERI) by an (n,gamma) reaction. Ho-166 has a half-life of 26.8 h and emits a high-energy beta particle with a maximum energy of 1.85 MeV. GafChromic film was used for the estimation of the absorbed dose of beta particles. A Co-60 teletherapy source and a 6 MV photon beam from a linear accelerator were used to generate dose-optical density calibration curves. The exposed films were read using a videodensitometer. With a modified micrometer, the film was positioned accurately on the surface of the balloon in water. The balloon was filled with Ho-166 solution to a pressure of 4 atm. Several film exposures were made with varying irradiation times and activities. The radiation absorbed dose rates were 1.02, 0.51 and 0.35 Gy x min(-1) x GBq(-1) x ml(-1) at the balloon surface, 0.5 and 1 mm from the balloon surface, respectively. The absorbed dose distribution revealed that Ho-166 is a good source for endovascular irradiation as the beta range is very short, avoiding unnecessary irradiation of normal tissue. A clinically applicable irradiation and duration of exposure were achievable utilizing our system.

Transjugular liver biopsy: modified Ross transseptal needle versus quick-core biopsy needle

BACKGROUND

We evaluated the differences in sample adequacy and safety between a transseptal needle and Quick-core biopsy needle for transjugular liver biopsy.

METHODS

Eighteen consecutive patients who had a bleeding diatheses and/or ascites underwent transjugular liver biopsy using a transseptal needle (11 patients) and Quick-core biopsy needle (seven patients). The length of the specimens was measured before fixation. A pathologist reviewed histologic slides for sample adequacy and pathologic diagnoses. Clinical records were reviewed for complication.

RESULTS

In all patients, liver biopsy was successful. A total of 45 specimens were obtained, with an average of 2.5 passes per patient. The length of specimen was significantly longer with the Quick-core biopsy needle than with the transseptal needle (p<0.05). Biopsied tissue was fragmented in 17 of 25 specimens with the transseptal needle but not fragmented in any specimen with the Quick-core biopsy needle. All specimens were determined to be adequate except one with the transseptal needle. There was no early or delayed complication in any patient.

CONCLUSION

Transjugular liver biopsy is a safe and effective procedure without any significant difference in complication and adequacy when using a transseptal needle or Quick-core biopsy needle. Larger specimens can be obtained without tissue fragmentation with the Quick-core biopsy needle.

Effect of transcatheter endovascular radiation with holmium-166 on neointimal formation after balloon injury in porcine coronary artery

BACKGROUND

Neointimal formation in response to arterial injury is a major contributing element in restenosis after coronary balloon angioplasty and stenting. Endovascular irradiation has been reported to be effective in reducing restenosis. The purpose of this study was to investigate the effect of beta-emitting holmium-166 for the inhibition of neointimal formation in porcine coronary artery.

METHODS AND RESULTS

A total of 34 pigs weighing 25 to 30 kg underwent oversized balloon injury (balloon/artery ratio, 1.3:1.4) at the proximal portion of the left anterior descending and circumflex arteries. One artery was randomly assigned to receive radiation after injury. Ho-166 was left in the balloon within the delivery catheter for a period sufficient to deliver 9 Gy and 18 Gy to a depth of 1 mm from the surface of the balloon. Four weeks later, pigs were sacrificed and hearts were perfusion-fixed, followed by histopathologic analysis and planimetry for measurement of maximal intimal thickness, intimal area, and fracture length. The coronary segment of the pigs in the control group had neointimal area of 1.18+/-0.55 mm2; the pigs in the 9-Gy group had neointimal area of 0.68+/-0.40 mm2 (P<.05 vs. control); and the pigs in the 18-Gy group had neointimal area of 0.29+/-0.12 mm2 (P<.01 vs. control). The maximal intimal thickness in the 18-Gy group (0.14+/-0.11 mm) was significantly reduced compared with the maximal intimal thickness in the control group (0.48+/-0.13 mm) (P<.01).

CONCLUSIONS

Intracoronary radiation with liquid Ho-166 contained in a perfusion balloon catheter is feasible and effective in reducing neointimal formation after coronary overstretch injury in pigs. Therefore intracoronary irradiation on the injured segment may further reduce restenosis after balloon injury.

Treatment of Bowen's disease with a specially designed radioactive skin patch

Bowen's disease can be treated by various methods, including surgical excision, cryosurgery, laser ablation, curettage, Mohs' microsurgery and ionizing radiation. Radiotherapy has been a useful therapeutic modality in the treatment of Bowen's disease and other skin cancers in areas which are difficult to excise, especially the central areas of the face, including eyelids, nose and lips. To overcome some of the disadvantages of external radiotherapy, a specially designed skin patch coated with high-energy beta-emitter holmium-166 was made for topical application at our institute. Twenty-nine sites of Bowen's disease in eight patients, confirmed by skin biopsy, were treated with 166Ho patches. The patches were applied to the surface of skin cancers for 30-60 min for a total radiation dose of 35 Gy (3500 rads). One to two weeks after application of the 166Ho patch, desquamation, erythema or erosion developed in treated sites, but these acute radiation reactions healed gradually with epithelial regeneration, and they showed good functional and cosmetic results without any complications. Follow-up biopsies were performed 1-5 months after 166Ho patch therapy, and they did not show any signs of Bowen's disease. One to two years after treatment with 166Ho skin patches, there were no recurrences of Bowen's diseases and no late complications. The 166Ho patch is an effective and convenient alternative method for the treatment of Bowen's disease that yields good cosmetic and functional results.

Psoralen-ultraviolet A-induced erythema: sensitivity correlates with the concentrations of psoralen in suction blister fluid

Since the advent of psoralen-ultraviolet A (PUVA) therapy, the value of plasma 8-methoxypsoralen (8-MOP) concentrations to predict PUVA-induced erythema has been widely investigated. Plasma 8-MOP concentrations have not been proportional to, and cannot alone predict, the degree of PUVA-induced erythema. We assumed that PUVA-induced erythema was related more closely to psoralen concentrations in the skin tissue rather than those within blood vessels. This study was designed to investigate the correlations between the 8-MOP concentrations in suction blister fluid (SBF) and in plasma, with the degree of PUVA-induced erythema. 8-MOP concentrations in plasma and SBF were measured in 15 vitiligo patients and 11 volunteers. Blood and SBF samples were collected 2 h after taking 8-MOP, and 8-MOP concentrations in plasma and SBF were quantified using reverse-phase high-performance liquid chromatography. Eleven volunteers were phototested using a series of doses of ultraviolet A at the time of sampling. The erythema responses were estimated visually to determine the minimal phototoxic dose (MPD). SBF 8-MOP concentrations showed a weak positive correlation with plasma 8-MOP concentrations, which means that we could not predict the exact SBF 8-MOP concentrations using the plasma 8-MOP concentrations. The MPD showed a better correlation with the log of the SBF 8-MOP concentration than with that of the plasma 8-MOP concentration. These results show that plasma 8-MOP concentration cannot represent the exact SBF 8-MOP concentration, and that SBF 8-MOP concentrations, which are representative of the skin tissue 8-MOP level, are more closely related to the erythemal sensitivity during PUVA therapy.

Resurfacing of facial angiofibromas in tuberous sclerosis patients using CO2 laser with flashscanner

BACKGROUND

Angiofibromas are a common presentation of tuberous sclerosis. They cause considerable cosmetic and hygienic morbidity for patients. Treatments of angiofibromas have included curettage, cryosurgery, chemical peel, dermabrasion, shave excision, and 13-cis retinoic acid. Results from these modalities in many cases were not satisfactory from a cosmetic standpoint. Copper vapor, argon, pulsed dye, and CO2 lasers have been used with success in isolated cases.

OBJECTIVE

The purpose of this study was to evaluate the efficacy of CO2 laser resurfacing with flashscanner in the treatment of facial angiofibromas.

METHODS

Two patients with angiofibromas on the face were treated with a CO2 laser with flashscanner. The cheek and nose were treated in one patient, and entire face was done in the other.

RESULTS

Both patients showed remarkable cosmetic improvements without scarring. Mild hyperpigmentation was found in both patients, which disappeared in 1 month with the application of topical agents. Facial erythema persisted about 2 months in both patients.

CONCLUSION

A CO2 laser equipped with flashscanner causes less residual thermal damage than conventional CO2 lasers and enables controlled depth vaporization for more precise and regular removal of angiofibromas. In whole-face resurfacing, more cosmetically acceptable results are possible because localized treatment leaves marginal prominences. Laser resurfacing is an effective alternative in the treatment of multiple protuberant angiofibromas even though we cannot permanently clear these lesions due to their nature.

CT features of abdominal manifestations of primary antiphospholipid syndrome

PURPOSE

The purpose of this work was to evaluate the CT features of the abdominal manifestations of primary antiphospholipid syndrome (PAPS).

METHOD

Of the 32 patients who were confirmed to have PAPS among 751 patients with elevated antiphospholipid antibodies during a 2 year period, we retrospectively reviewed the 14 patients who underwent abdominal CT. The clinical indications for abdominal CT included abdominal pain, abdominal distension, or lower leg swelling. CT findings were analyzed with regard to the abdominal vascular system and abdominal organ involvement patterns as well as ancillary findings.

RESULTS

Of the 14 patients with PAPS, 10 had involvement of the venous system (72%), 2 of the arterial system (14%), and 2 of both systems (14%). Of the 12 patients who had venous system involvement, 4 had thrombosis in the inferior vena cava (IVC), 2 in both the IVC and the hepatic vein, 1 in the IVC and splenic and portal veins, 1 in the IVC and hepatic and adrenal veins, 1 in the hepatic, portal, and renal veins, and 3 in the portal and superior mesenteric veins. Budd-Chiari syndrome developed in five of the nine patients who had thrombosis of the IVC or hepatic vein. Arterial thrombosis was noted in four patients, hepatic artery in two, aorta in one, renal artery in one, pancreatic arcade in one, and splenic artery in one, with infarct of multiple organs including the liver, jejunum, colon, kidney, and adrenal gland. Seven of the 14 patients (50%) manifested thrombosis or infarct of multiple extra-abdominal organs.

CONCLUSION

PAPS should be included in the differential diagnosis when CT demonstrates infarcts in multiple organs or patients have recurrent episodes of venous or arterial thrombosis.

The effect of external electron beam on neointima in rat carotid artery injury model

PURPOSE

Endovascular irradiation with either a gamma or a beta source has shown to reduce neointimal proliferation. However, the effect of external-beam radiation on neointimal hyperplasia is controversial. The objective of this study was to determine the effect of external-beam irradiation with different doses on neointimal hyperplasia in the rat carotid artery injury model.

METHODS AND MATERIALS

Twenty-seven Sprague-Dawley rats underwent endothelial denudation injury by 2F Fogarty balloons on carotid artery. Immediately after the injury, rats were irradiated externally using 6-MeV electrons. Rats were grouped according to the radiation doses, 0 Gy as controls (n = 5), 5 Gy (n = 5), 10 Gy (n = 5), 15 Gy (n = 6), and 20 Gy (n = 6). Then, rats were sacrificed after 2 weeks and the carotid arteries were perfusion-fixed in paraformaldehyde. External elastic lamina (EEL) area, lumen area, maximal intimal thickness (MIT), and intimal area (IA) of the injured segments were measured on the basis of histomorphometry.

RESULTS

In EEL and lumen area, there was no statistically significant difference between the irradiated groups and the controls. In MIT and IA, low-dose radiation (5 Gy and 10 Gy) did not induce any significant reduction. High-dose radiation (15 Gy and 20 Gy), however, reduced MIT and IA significantly.

CONCLUSION

External electron beam reduced the intimal area, and the inhibition of neointimal proliferation was dependent upon radiation doses. This study suggests that the minimal effective dose for the inhibition of neointimal hyperplasia following denudation injury in the rat carotid model is between 10 Gy and 15 Gy.

Modified small-bowel follow-through: use of methylcellulose to improve bowel transradiance and prepare barium suspension

PURPOSE

To evaluate the efficacy of barium suspension prepared in methylcellulose (MC) in modified small-bowel follow-through (SBFT).

MATERIALS AND METHODS

The authors evaluated 155 patients who underwent modified SBFT with oral administration of MC after ingesting barium suspension. Of these patients, 52 received 40% suspension in MC, 46 received 40% suspension in water, and 57 received 70% suspension in water. Patients were divided into normal (n = 74) and abnormal (n = 81) groups according to the final results. The image quality, transit time to the cecum, and time to and frequency of flocculation were compared for both groups.

RESULTS

In the normal group, the quality of the images in patients receiving 40% suspension in MC or 70% suspension in water was superior to that of images in patients receiving 40% suspension in water. In the abnormal group, the best image quality was achieved for the patients who received 40% suspension in MC. In the normal group, the difference in transit time between the three preparations was not substantial. In the abnormal group, however, the 40% suspension in MC showed the fastest transit time. Use of the 40% suspension in MC helped lower the frequency of flocculation in the normal group.

CONCLUSION

Use of 40% barium suspension in MC is effective for improving the image quality in modified SBFT.

Serum concentration of the soluble interleukin-2 receptor in vitiligo patients

Serum levels of sIL-2R can be used to monitor in vivo immune activation and its elevation have been shown to be correlated with T cell mediated immune disease such as atopic dermatitis, psoriasis, lymphoma and systemic sclerosis. Vitiligo is the disease of depigmentation caused by destruction of melanocytes, and there have been extensive studies on the immune pathogenesis. If the pathogenesis of vitiligo is correlated with the activation of T lymphocytes, the change of IL-2R will be detected compared with that of normal control. Therefore we sought the change in sIL-2R to determine whether T lymphocytes from patients with vitiligo show abnormal biological behavior. The quantitation of sIL-2R was done by sandwich enzyme-linked immunosorbent assay (ELISA) from the sera of 79 vitiligo patients and 40 normal controls. The results were summarized as following. The sIL-2R level in vitiligo patients (671.91 +/- 368.59 U/ml) was significantly increased compared with that of controls (370.8 +/- 71.8 U/ml; P < 0.005). According to clinical types, sIL-2R level in focal type of vitiligo patients was significantly higher than those in other types (segmental or generalized; P < 0.05). The sIL-2R level in patients less than 1 year duration was significantly higher than in patients more than 1 year duration (P < 0.05). The sIL-2R levels were not significantly different between active and inactive group. There was no significant differences among sIL-2R levels according to sex or age of onset. Our study showed that sIL-2R level was higher in vitiligo patients compared with that of normal controls, so the activation of T lymphocytes would be an important component in the pathogenesis of vitiligo. The higher sIL-2R levels in recent onset group would suggest that sIL-2R level might be an acute immunologic marker in vitiligo patients.

Arginine in the beginning of the 1A rod domain of the keratin 10 gene is the hot spot for the mutation in epidermolytic hyperkeratosis

Keratin intermediate filaments are expressed in specific type I/type II pairs in the stage of differentiation of keratinocytes. The mutations in the keratin genes expressed in the epidermis are etiologically responsible for several epidermal genetic skin diseases, such as epidermolysis bullosa simplex, epidermolytic hyperkeratosis (EHK), ichthyosis bullosa of Siemens, palmoplantar keratoderma, pachyonchia congenita and white sponge nevus. The mutations of keratins 1/10 which are expressed in spinous and granular layers are confirmed to cause EHK. There are several trials to correlate between the clinical phenotypes and sites of mutations of the keratin genes. One of these is that EHK is divided into two groups: the palms and soles involvement (PS) group and the non-palms and soles (NPS) group. So far the PS group had the mutations in the keratin 1 and the NPS group in keratin 10. Most of the mutations of the NPS group were reported in the beginning of the 1A rod domain and over 2/3 of the mutations in the 1A rod domain were the base pair substitution of arginine. Here we find two different mutations in two unrelated Korean kindreds classified as NPS group-R156C and R156H-in the 1A rod domain of keratin 10. Our results are compatible with the above classification and suggest that the arginine in the beginning of the 1A rod domain is the hot spot for the mutation of the keratin 10 gene.

Biodistribution and kinetics of holmium-166-chitosan complex (DW-166HC) in rats and mice

The fate of 166Ho-chitosan complex, a radiopharmaceutical drug for cancer therapy, was determined by studying its absorption, distribution and excretion in rats and mice.

METHODS

Holmium-166-chitosan complex [0.75 mg of Ho(NO3)3 x 5H2O and 1 mg chitosan/ head] was administered intrahepatically to male rats. Radioactive concentrations in blood, urinary and fecal excretion and radioactive distribution in tissues were examined. To determine the effects of chitosan in 166Ho-chitosan complex, 166Ho alone [0.75 mg of Ho(NO3)3 x 5H2O/head] was intrahepatically administered to male rats, and radioactive concentrations in blood, urinary and fecal excretion and radioactive distribution were examined. In B16 melanoma-transplanted nude mice, radioactive distribution after intratumoral administration of 166Ho-chitosan complex [0.075 mg of Ho(NO3)3 x 5H2O and 0.10 mg chitosan/head] was investigated also.

RESULTS

After administration of 166Ho-chitosan complex, the radioactive concentrations in blood were low, and cumulative urinary and fecal excretions over a period of 0-72 hr were 0.53% and 0.54%, respectively. The radioactive concentrations in tissues and the whole-body autoradiography images showed that most of the administered radioactivity was localized at the administration site, and only slight radioactivity was detected from the liver, spleen, lungs and bones. On the other hand, results of intrahepatic administration of 166Ho alone showed high radioactive concentrations in the blood, and the whole-body autoradiographs showed that the administered radioactivity was distributed in many organs and tissues. These results strongly suggest that 166Ho is retained at the administration site only when it forms a chelate complex with chitosan. Autoradiographs after intratumoral administration of 166Ho-chitosan complex showed that radioactivity was localized at the site of administration without distribution to the other organs and tissues.

CONCLUSION

Administered 166Ho-chitosan complex is retained at the administration site after either intrahepatic or intratumoral administration to rats or tumor-transplanted nude mice.

Mutations in the 1A rod domain segment of the keratin 9 gene in epidermolytic palmoplantar keratoderma

Palmoplantar keratodermas (PPK) constitute a heterogeneous group of diseases marked by the thickening of palms and soles of affected individuals. They are divided into autosomal dominant and autosomal recessive groups by the mode of transmission. The autosomal dominantly transmitted group is further divided into epidermolytic (EPPK, Voerner) and non-epidermolytic (NEPPK, Unna-Thost) types according to the histopathologic findings. Recent development of molecular approaches has confirmed that EPPK and NEPPK are caused by the mutations in keratin 9 and 1 genes, respectively. We have studied three families of EPPK to find the mutation in the keratin 9 gene. DNA sequence analyses revealed single base changes in sequences encoding the highly conserved 1A rod domain segment of the keratin 9 gene in two of the three families. These mutations caused Arg (CGG) to Glu (CAG; R162Q) and Arg (CGG) to Try (TGG; R162W) substitutions. The same arginine position has been mutated in the keratin 10 gene in epidermolytic hyperkeratosis, the keratin 14 gene in epidermolysis bullosa simplex, and the keratin 9 gene in hereditary EPPK in Western patients. In this study we show that unrelated Korean patients have similar mutations.

A glutamate to lysine mutation at the end of 2B rod domain of keratin 2e gene in ichthyosis bullosa of Siemens

Ichthyosis bullosa of Siemens is a rare autosomal dominant skin disorder whose clinical findings are quite similar to those of epidermolytic hyperkeratosis. The differences between those two diseases include absence of erythroderma and different distributions in the skin in ichthyosis bullosa of Siemens. Recent studies have confirmed that ichthyosis bullosa of Siemens is caused by the mutation in the keratin 2e (K2e) gene, which is expressed in the upper spinous and granular layers. We have identified a sporadic case of ichthyosis bullosa of Siemens; based on diagnosis by histopathological findings, the K2e gene of the patient was analysed. Direct sequencing of PCR products revealed a single base change in sequences encoding the highly conserved end of the 2B rod domain segment of the K2e gene. This mutation results in substitution of the codon for glutamic acid by a codon for lysine in position 493 in K2e (E493K). Mutations of the K2e gene involving five different residue positions (Q187P, T485P, L490P, E493D, E493K and E494K) are known to cause ichthyosis bullosa of Siemens. Of these sites, E493, which is conserved in type I and type II keratin genes, is the most frequently altered amino acid in the K2e gene. These data together suggest that this codon constitutes a hot spot for mutations in the K2e gene.

Use of methylcellulose in small bowel follow-through examination: comparison with conventional series in normal subjects

BACKGROUND

To evaluate and optimize a modified small bowel follow-through examination (SBFT) by using an oral administration of a large amount (600 mL) of methylcellulose after taking a small amount of barium.

METHODS

Ninety-nine normal subjects underwent modified SBFT with an oral administration of 600 mL of 0.5% methylcellulose after taking 100 mL of 120% or 100, 150, or 200 mL of 70% w/v barium. The transradiancy and distensibility of the bowel and the transit time were compared with those of 39 other normal subjects who underwent conventional SBFT with 500 mL of 70% w/v barium.

RESULTS

Except for two subjects who developed diarrhea immediately after examination, no patients complained of acute symptoms, such as abdominal pain or vomiting. Modified SBFT was much superior to conventional series for obtaining good bowel transradiancy and rapid transit time (range = 37-49 min), but bowel distention was not significantly improved. The use of 150 mL of 70% w/v barium was better than the other three modified techniques for achieving good bowel transradiancy, rapid transit time, and less occurrence of flocculation.

CONCLUSION

Modified SBFT is a simple method for easily improving the image quality in terms of bowel transradiancy and transit time.

Toxicities of 166Holmium-chitosan in mice

166Holmium (166Ho) is a radionuclide of rare earth chemical and is known to have antitumor activity. Several chemicals were complexed with 166Ho to facilitate the transport of this radionuclide to the site of action. In this study, 166Ho was complexed to chitosan (Chit) which decreases the distribution of Ho into other tissues when applied intrahepatically. To investigate the single dose toxicity, mice were administered intravenously with 1 mCi/kg body weight of 166Ho-Chit (DW-166HC), Chit or nothing. Organ weights, hematological and histopathological studies were performed in 6 animals per group at 1, 3 and 14 days after administration. In 166Ho-Chit treated animals, a slight decrease of erythrocyte number was observed at day 14 and increases of relative liver and lung weights were found at day 3. Although marked multiple necrotic foci in the white pulp and depletion of marginal zone in the spleen were noted at day 1, these findings were decreased in severity and fully recovered at day 3 and day 14, respectively. Slightly decreased kidney weights were observed both in Chit and in 166Ho-Chit treated groups without histological alterations. Thus it is suggested that most effects of 166Ho-Chit observed at an early stage after administration are limited to rapidly dividing cells and reversible within 14 days.

Radionuclide therapy of skin cancers and Bowen's disease using a specially designed skin patch

Skin cancer is the most common malignancy in humans. Therapeutic modalities for skin cancer are local destruction, radiotherapy and surgery. External radiation therapy leads to good results, however, generally 5-6 wk of treatment is needed to deliver optimal radiation dose to tumors. In this study, a beta-emitting radionuclide, 166Ho, impregnated in a specially designed patch, was used on superficial skin cancers and Bowen's disease for local irradiation.

METHODS

Ten mice with chemically induced skin tumors were studied. Five-millimeter size patches containing 22.2-72.15 MBq (0.6-1.95 mCi) 166Ho were applied to the tumor surface for 1-2 hr. In a human trial, patients with squamous-cell carcinoma (n = 3), basal cell carcinoma (n = 1) and Bowen's disease (n = 1) were treated with patches containing 273.8-999 MBq (7.4-27 mCi) of 166Ho for 30 min to 1 hr. Pathologic examination was performed 4-7 wk after treatment in an animal model. Skin biopsy was performed 8 wk post-treatment in four patients.

RESULTS

Tumor destruction was seen 1 wk post-treatment, however, radiation dermatitis or ulceration developed at the site of radionuclide application. Those reactions healed gradually with fibrosis or epithelialization, which was confirmed pathologically. No significant adverse reaction to radiation except subcutaneous fibrosis was found.

CONCLUSION

Superficial skin tumors could be successfully treated by topical application of beta-emitting radionuclides.

Relationship between squamous cell carcinoma antigen levels and tumor volumes in patients with cervical carcinomas undergoing neoadjuvant chemotherapy

This study was performed to determine whether there is a linear correlation between serum squamous cell carcinoma (SCC) antigen levels and tumor volumes in patients with cervical carcinoma. Sera from 43 patients with stage IIb bulky (>4 cm) cervical carcinoma were collected prospectively and assayed for SCC antigen levels before, and 2 weeks after, three courses of neoadjuvant chemotherapy. At the same time, tumor volume was measured by pelvic magnetic resonance imaging (MRI). Mean serum SCC antigen level declined significantly after neoadjuvant chemotherapy, from 16.8 ng/ml (range 0.4-80.2 ng/ml) to 3.1 ng/ml (range 0.1-13.0 ng/ml) (P = 0.0001). Also, the percentage of patients with elevated serum SCC antigen level decreased significantly from 79.1 to 25.6% (P < 0.001). Furthermore, mean tumor volume also declined significantly after neoadjuvant chemotherapy, from 54.1 cm3 (range 8.4-133.9 cm3) to 5.3 cm3 (range 0-77.8 cm3) (P = 0.0001). However, serum SCC antigen levels did not show a linear correlation with tumor volumes before and after neoadjuvant chemotherapy (r = 0.0776, P = 0.6208; r = 0.1887, P = 0.2256, respectively). Interestingly, the percentage reduction in serum SCC antigen levels showed a linear correlation with that of tumor volume after neoadjuvant chemotherapy in 34 patients who had elevated prechemotherapy serum SCC antigen levels (r = 0.5094, P = 0.0021). These results suggest that although serum SCC antigen level does not have a direct linear relationship to tumor volume, reduction in serum SCC antigen level has a linear correlation with that of tumor volume after neoadjuvant chemotherapy in patients with cervical carcinoma and elevated prechemotherapy SCC antigen levels.

A novel H1 mutation in the keratin 1 chain in epidermolytic hyperkeratosis

We report a novel mutation in a case of epidermolytic hyperkeratosis that results in a proline for arginine substitution in the penultimate residue position of the H1 subdomain of the keratin 1 chain, which is near the beginning of the rod domain. This causes a severe clinical disease classified as PS-2. Therefore, the H1 subdomain is probably equally important for the maintenance of keratin intermediate filament integrity as the rod domain. Since earlier concepts had implied that mutations in the H1 subdomain produce milder disease, this case suggests that attempts to correlate mutations with disease presentation remain problematic.

Intraoperative stimulation of pedicle screws: a new method for verification of screw placement

Pedicular fixation of the lumbosacral spine has become a popular procedure for improving fusion rates. Even in experienced hands, it can be associated with a significant rate of screw malpositioning and potential nerve root injury. In this report, we describe a technique for improving screw localization utilizing evoked electromyography responses from direct stimulation of pedicle instrumentation.

p53 mutation in epithelial ovarian carcinoma and borderline ovarian tumor

We have investigated a series of 19 human ovarian carcinomas and 17 borderline ovarian tumors to determine the loss of heterozygosity on chromosome 17p and possible concurrent p53 mutations. Allelic losses were assessed using restriction fragment length polymorphism study, and p53 gene mutations were detected by single strand conformation polymorphism analysis and by direct sequencing. In addition, we stained the same tumor sections immunohistochemically to detect p53 protein in tissues. Among 19 ovarian malignant tumor samples tested, we identified 17p allelic deletions in 12 (63.2%) of 19 informative cases. The p53 gene mutation was observed in 7 of 19 (36.8%) malignant ovarian tumors, and it was predominantly observed in tumors with allelic loss on 17p (six of seven tumors, 85.7%). Although 9 cases of 17 borderline ovarian tumors showed shifted bands on single strand conformation polymorphism analysis, only one case was proved to have a point mutation in direct sequencing. We also obtained six cases (31.6%) of positive immunoreactivity from 19 ovarian cancers and 3 cases (17.6%) from 17 borderline ovarian tumors. We conclude that loss or inactivation of tumor suppressor gene function by chromosome 17p allelic deletions or p53 mutations are important genetic changes in ovarian cancer.

Phase I/II study of neoadjuvant intraarterial chemotherapy with mitomycin-C, vincristine, and cisplatin in patients with stage IIb bulky cervical carcinoma

BACKGROUND

Stage IIb bulky cervical carcinomas have been considered difficult to treat successfully by radiation and/or surgery, compared with smaller lesions. This study was designed to evaluate the efficacy of neoadjuvant pelvic intraarterial chemotherapy (IAC) and to determine the optimal dosage of cisplatin for reducing tumor volume in these patients.

METHODS

Twenty-one previously untreated patients with primary cervical carcinoma of more than 4 cm in greatest dimension and parametrial invasion were included in this study. Pelvic IAC was administered using a combination of mitomycin-C, 10 mg/m2; vincristine, 1 mg/m2; and cisplatin, 50 mg/m2 (MVC; group 1, 8 patients) or 75 mg/m2 (group 2, 13 patients). Tumor volumes were measured three-dimensionally by magnetic resonance imaging (MRI) before and after three courses of IAC. Clinical responses were evaluated with gynecologic examination and MRI; pathologic responses were evaluated with histologic examinations of surgical specimens.

RESULTS

The mean volume reduction rate (74.2% vs. 97.2% in groups 1 and 2, respectively, P = 0.0022), the clinical complete response rate (0% vs. 69.2%, P = 0.0033), and the pathologic complete response rate (0% vs. 46.2%, P = 0.0445) were significantly higher in group 2. Type III radical hysterectomy was possible in 19 patients (90.5%). Toxicities of grades 2-3 (World Health Organization criteria) were nausea and/or vomiting (38.1%), leukopenia (33.3%), and fever (14.2%).

CONCLUSIONS

These preliminary results suggest that neoadjuvant pelvic IAC with MVC (especially with cisplatin at a dose of 75 mg/m2) is effective in reducing tumor volume, increasing the clinical and pathologic complete response rate, and improving the operability in most patients with Stage IIb bulky cervical carcinoma, generally considered inoperable.

A study of skin responses to follow-up, rechallenge and combined effects of irritants using non-invasive measurements

Irritant contact dermatitis is a common clinical problem. Primary irritation can be easily recognized, but cumulative irritation by daily exposure is hard to be diagnosed and the condition may fail to be clear even away from work. The mechanism of irritant dermatitis produced by repeated or combined exposure to clinical or subclinical doses of irritants is still poorly understood. In order to find out whether the subclinical doses of irritants affect each other by repeated or combined exposure according to their concentrations, non-invasive measurements, transepidermal water loss and laser Doppler flowmetry were used. Sodium lauryl sulfate, sodium hydroxide and benzalkonium chloride were serially diluted and patch-tested with large Finn chambers on Scanpor tape on the back of normal human volunteers and responses were followed up for 7 days. Twice repeated exposure with subclinical doses of irritants at 1 day intervals were also performed. Repeated daily applications for 5 days with subclinical doses of single or premixed irritants were performed to know the combined irritating effect. The irritant response was well correlated to the concentration of the irritants. However, increased response was not observed when subclinical doses were rechallenged on the previously patch tested sites. Twice-repeated exposure of subclinical doses of irritants increased skin irritancy when measured by transepidermal water loss and laser Doppler flowmetry. Some correlation and some discrepancies were observed between different evaluation methods in combined and repeated application tests with irritants of subclinical doses. Responses of skin irritancy induced by subclinical doses showed somewhat different pattern from that given strong irritants.(ABSTRACT TRUNCATED AT 250 WORDS)

Loss of heterozygosity on the short arm of chromosome 17 in uterine cervical carcinomas

DNA samples from 26 cervical carcinoma and normal tissue pairs were studied by restriction fragment length polymorphism (RFLP) analysis to determine the frequency of loss of heterozygosity (LOH) on 17p. Allelic loss in the p13.1 region of chromosome 17, known to contain the TP53 locus, was not detected in any of 10 informative cases. Instead, LOH was detected on 17p13.3 in eight (40%) of 20 informative cases with at least one of two 17p13.3 markers. Examination of the intragenic region of p53 in the same samples using polymerase chain reaction (PCR)-RFLP analysis showed no LOH in the gene (none of 16 informative individuals).

Enoxacin photosensitivity

A 71-year-old Korean farmer had pruritic erythematous patches on sun-exposed areas after enoxacin treatment for prostatitis. Suggestive features of photoallergy, such as moderate blurring of the margin and possible ectopic flare phenomenon, were reproduced by oral provocation test with enoxacin. Because all quinolones have structural similarities, and photosensitivity was observed in nalidixic acid and enoxacin, it would be advisable to warn all patients taking quinolones about photosensitivity.

Purification and characterization of intracellular proteases of Clostridium perfringens type A

Five intracellular proteases from sporulating cells of Clostridium perfringens type A were identified and three could be separated by DEAE-Sephacel. Two, I-A and I-B, had caseinolytic activity and one, I-C, was only active on N-benzoyl-DL-arginine-p-nitroanilide. I-A and I-B could each be further separated by Sephacryl S-300 into I-A-1 and I-A-2 and I-B-1 and I-B-2, respectively. I-A-1, a chymotrypsin-like enzyme, was the major intracellular protease, constituting 74% of the intracellular caseinolytic activity. In addition to cytoplasmic proteases both trypsin and chymotrypsin-like enzyme activity was associated with the membrane fraction. I-A-1 had a molecular weight of 330,000, with subunits of 120,000 and 138,000. I-A-1 cleaved a 1200 molecular weight peptide from C. perfringens enterotoxin. Early sporulating cell extracts of C. perfringens contained three presumptive enterotoxin precursors, which disappeared following treatment with I-A. Such cells also contained at least 10 spore coat related proteins, only one (51,500 molecular weight) of which was sensitive to I-A-1. The results indicate a possible role for the major intracellular protease in the processing of C. perfringens enterotoxin and a less important role, if any, in spore coat formation.

Proteolysis of Clostridium perfringens type A enterotoxin during purification

The small satellite bands of enterotoxin frequently seen in polyacrylamide gels following purification of Clostridium perfringens enterotoxin were found to be due to endogenous protease activity and were not present if phenylmethylsulfonyl fluoride (PMSF; 1 mM) and EDTA (10 mM) were used in the purification protocol. The use of PMSF was avoided by passing gel filtration-purified enterotoxin material through DEAE-Sephacel. This modified protocol resulted in an 11.4-fold purification of enterotoxin and a 26.8% yield. Contrary to previous reports (B. R. Dasgupta and M. W. Pariza, Infect. Immun. 38: 592-597, 1982), if PMSF and EDTA were included during purification, we were unable to detect the novel enterotoxin ET-1 produced by strain NCTC 10240. C. perfringens proteases cleaved homogeneous enterotoxin into two additional fragments, suggesting that ET-1 was a product of endogenous protease action during purification.

Artifacts following gold staining of Western-blotted membranes

Protein samples were separated by sodium dodecyl-sulfate-polyacrylamide gel electrophoresis, electrophoretically transferred to nitrocellulose membranes, and stained with colloidal gold. Three artifact bands appeared demonstrating apparent molecular weights of 58,000, 63,000, and 65,000. The appearance of these bands was due to oxidized dithiothreitol used to denature the proteins prior to electrophoresis. The appearance of the artifact bands could be avoided by the addition of excess iodoacetamide to the denatured protein sample and by limiting staining time to 1.5 h at 13 V/cm.

Relation between severity of chronic illness and adjustment in children and adolescents with sickle cell disease

Tested the relationship between illness severity and adjustment in 70 sickle cell patients, aged 8-16. Illness severity was measured by frequency of hospitalization and emergency room visits, frequency and intensity of pain crises, and duration of illness. Adjustment variables were IQ, self-esteem, social and personal adjustment, behavioral problems, school performance, and peer relations. Medical variables-associated illness patterns and type of hemoglobinopathy-were also considered. Sex and age were covariates. The hypothesis that illness severity would affect adjustment was generally not supported. Other factors such as SES, family structure, or support systems may affect adjustment and suppress the hypothesized relationship. The need for a more global intervention approach than using illness severity to measure need for psychotherapeutic assistance is suggested.

Radioimmunoassay of Pinellia ternata lectin

Radioimmunoassay of Pinellia ternata lectin (PTL) in rabbit serum and in root extract has been tried. The PTL was labelled with 125I using chloramine-T, and the labelled product was purified by gel chromatography. Standard suppression lines were obtained and the parallelism in serum or buffer was demonstrated. The assay time was 48 h with an intra- and inter-assay coefficient of variation of less than 12%. The PTL content in dried Pinellia ternata roots was about 28 +/- 3 mg/g. More than 40% of the i.v. injected PTL to rabbits was retained in serum at 1 h post administration.