Alterations of Fas (APO-1/CD95) gene in transitional cell carcinomas of urinary bladder

Fas (Apo-1/CD95) is a cell-surface receptor involved in cell death signaling. The key role of the Fas system in negative growth regulation has been studied mostly within the immune system, and somatic mutations of Fas in cancer patients have been described solely in lymphoid-lineage malignancies. We analyzed somatic mutations and loss of heterozygosity of Fas gene in 43 transitional cell carcinomas of urinary bladder. Overall, 12 tumors (28%) were found to have Fas mutations, including 11 missense mutations and 1 frameshift mutation. Ten of the 12 mutations were located in the death domain known to be involved in the transduction of an apoptotic signal, and 8 of these 10 mutations showed an identical G to A transition at bp 993, indicating a potential hotspot in bladder cancers. Three of eight (38%) informative tumors carrying Fas mutations showed LOH at polymorphic sites in the promoter region. This is the first report on the Fas gene mutations in nonlymphoid malignancies, and our data suggest that alterations of the Fas gene might lead to the loss of its apoptotic function and contribute to the pathogenesis of some bladder cancers.

Nonaggregating mutant of recombinant human hexokinase I exhibits wild-type kinetics and rod-like conformations in solution

Hexokinase I governs the rate-limiting step of glycolysis in brain tissue, being inhibited by its product, glucose 6-phosphate, and allosterically relieved of product inhibition by phosphate. On the basis of small-angle X-ray scattering, the wild-type enzyme is a monomer in the presence of glucose and phosphate at protein concentrations up to 10 mg/mL, but in the presence of glucose 6-phosphate, is a dimer down to protein concentrations as low as 1 mg/mL. A mutant form of hexokinase I, specifically engineered by directed mutation to block dimerization, remains monomeric at high protein concentration under all conditions of ligation. This nondimerizing mutant exhibits wild-type activity, potent inhibition by glucose 6-phosphate, and phosphate reversal of product inhibition. Small-angle X-ray scattering data from the mutant hexokinase I in the presence of glucose/phosphate, glucose/glucose 6-phosphate, and glucose/ADP/Mg2+/AlF3 are consistent with a rodlike conformation for the monomer similar to that observed in crystal structures of the hexokinase I dimer. Hence, any mechanism for allosteric regulation of hexokinase I should maintain a global conformation of the polypeptide similar to that observed in crystallographic structures.

Alterations of Fas (Apo-1/CD95) gene in non-small cell lung cancer

Fas (Apo-1/CD95) is a cell-surface receptor involved in cell death signaling. The key role of the Fas system in negative growth regulation has been studied mostly within the immune system, and somatic mutations of Fas gene in cancer patients have been described solely in lymphoid-lineage malignancies. However, many non-lymphoid tumor cells have been found to be resistant to Fas-mediated apoptosis, which suggests that Fas mutations, one of the possible mechanisms for Fas-resistance, may be involved in the pathogenesis of non-lymphoid malignancies as well. In this study, we have analysed the entire coding region and all splice sites of the Fas gene for the detection of the gene mutations in 65 human non-small cell lung cancers by polymerase chain reaction, single strand conformation polymorphism and DNA sequencing. Overall, five tumors (7.7%) were found to have the Fas mutations, which were all missense mutations. Four of the five mutations identified were located in the cytoplasmic region (death domain) known to be involved in the transduction of an apoptotic signal and one mutation was located in the transmembrane domain. This is the first report on the Fas gene mutations in non-lymphoid malignancies, and the data presented here suggests that alterations of the Fas gene might lead to the loss of its apoptotic function and contribute to the pathogenesis of some human lung cancers.

In vivo expression of soluble Fas and FAP-1: possible mechanisms of Fas resistance in human hepatoblastomas

Many tumour cells express both Fas and its ligand (FasL) on their surface and it has remained a mystery why such cells do not simply kill themselves. It remains to be determined whether Fas and FasL are expressed in human hepatoblastomas and if so, what is responsible for the possible Fas resistance of these tumours. In this study, the expression of Fas and FasL was examined in 23 cases of human hepatoblastoma by immunohistochemical staining. To elucidate possible Fas resistance in hepatoblastomas, Fas-resistance pathways including the expression of bcl-2 and Fas-associated phosphatase-1 (FAP-1), and the expression of soluble Fas (sFas) mRNA, were analysed by immunohistochemistry and in situ reverse transcription-polymerase chain reaction (in situ RT-PCR). Fas gene mutation in the death domain was also examined. Fas and FasL were expressed in all hepatoblastomas analysed. Twenty (87 per cent) and 18 (78 per cent) cases of hepatoblastoma were positive for sFas mRNA and FAP-1, respectively, but none of the hepatoblastomas expressed bcl-2. Mutation in the death domain of the Fas gene was not found in hepatoblastomas. Taken together, these findings demonstrated that Fas, a death receptor, and its ligand are co-expressed in hepatoblastomas in vivo, but some inhibitors of Fas-mediated apoptosis are also expressed in these tumours. These results suggest that it is probably due to the action of inhibitory molecules of the Fas pathway that the tumour cells of hepatoblastomas do not kill themselves in an autocrine-driven cycle and that in this manner hepatoblastomas avoid apoptosis.

Cellular and molecular remodeling in a heart failure model treated with the beta-blocker carteolol

Broad-breasted white turkey poults fed furazolidone developed dilated cardiomyopathy (DCM) characterized by ventricular dilatation, decreased ejection fraction, beta1-receptor density, sarcoplasmic reticulum (SR) Ca2+-ATPase, myofibrillar ATPase activity, and reduced metabolism markers. We investigated the effects of carteolol, a beta-adrenergic blocking agent, by administrating two different dosages (0.01 and 10.0 mg/kg) twice a day for 4 wk to control and DCM turkey poults. At completion of the study there was 59% mortality in the nontreated DCM group, 55% mortality in the group treated with the low dose of carteolol, and 22% mortality in the group treated with the high dose of carteolol. Both treated groups showed a significant decrease in left ventricle size and significant restoration of ejection fraction and left ventricular peak systolic pressure. Carteolol treatment increased beta-adrenergic receptor density, and the high carteolol dose restored SR Ca2+-ATPase and myofibrillar ATPase activities, along with creatine kinase, lactate dehydrogenase, aspartate transaminase, and ATP synthase activities, to normal. These results show that beta-blockade with carteolol improves survival, reverses contractile abnormalities, and induces cellular remodeling in this model of heart failure.

Cellular and biochemical response of the human lung after intrapulmonary instillation of ferric oxide particles

Bronchoalveolar lavage (BAL) was used to sample lung cells and biochemical components in the lung air spaces at various times from 1 to 91 d after intrapulmonary instillation of 2.6 microm-diameter iron oxide particles in human subjects. The instillation of particles induced transient acute inflammation during the first day post instillation (PI), characterized by increased numbers of neutrophils and alveolar macrophages as well as increased amounts of protein, lactate dehydrogenase, and interleukin-8 in BAL fluids. This response was subclinical and was resolved within 4 d PI. A similar dose-dependent response was seen in rats 1 d after intratracheal instillation of the same particles. The particles contained small amounts of soluble iron (240 ng/mg) and possessed the capacity to catalyze oxidant generation in vitro. Our findings indicate that the acute inflammation after particle exposure may, at least partially, be the result of oxidant generation catalyzed by the presence of residual amounts of ferric ion, ferric hydroxides, or oxyhydroxides associated with the particles. These findings may have relevance to the acute health effects associated with increased levels of ambient particulate air pollutants.

Plasma lycopene concentrations in humans are determined by lycopene intake, plasma cholesterol concentrations and selected demographic factors

Higher plasma lycopene concentrations have been associated with a reduced risk of several chronic diseases. Determinants of lycopene concentrations in humans have received limited attention. We had blood lycopene concentrations and lycopene consumption data available from 111 participants in a two-center cancer prevention trial involving beta-carotene and examined determinants of plasma lycopene levels cross-sectionally. The median plasma lycopene level was 0.59 micromol/L (range 0.07-1.79). Low plasma concentrations of lycopene were associated with the following variables in univariate analyses: study site (Florida lower than Connecticut, P = 0.001), being nonmarried (P = 0.02), having lower income (P = 0.003), being nonwhite race/ethnicity (P = 0.03), having lower dietary lycopene intake (r = 0.29, P = 0.002), having lower plasma cholesterol (r = 0. 43, P = 0.0001) and triglyceride levels (r = 0.26, P = 0.005), and consuming less vitamin C (r = 0.20, P = 0.03). Women had slightly higher plasma lycopene levels than men (0.65 vs. 0.58 micromol/L; P = 0.31), despite lower dietary intake of lycopene (1,040 vs. 1,320 microg/d; P = 0.50). Plasma lycopene levels did not differ in smokers and nonsmokers. In stepwise regression analyses, the determinants of plasma lycopene were plasma cholesterol, dietary lycopene, and marital status; these three variables explained 26% of the variance in plasma lycopene. Relatively few lifestyle and demographic factors were important determinants of plasma lycopene levels, with plasma cholesterol, marital status, and lycopene intake being of greatest importance.

Paclitaxel, 5-fluorouracil, and cisplatin combination chemotherapy for the treatment of advanced gastric carcinoma

BACKGROUND

Although the clinical efficacy of paclitaxel in the treatment of gastric carcinoma has not been clearly defined, recent reports have suggested a possible role in the treatment of upper gastrointestinal carcinomas in vitro and in vivo. In this study, the authors evaluated the efficacy and toxicity of a combination chemotherapy that included paclitaxel, 5-fluorouracil (5-FU), and cisplatin in the treatment of patients with advanced gastric carcinoma.

METHODS

Forty-one gastric carcinoma patients with metastatic disease, unresectable advanced disease, or relapsed disease were treated with the following regimen, administered every 28 days: paclitaxel 175 mg/m2 by 3-hour intravenous (i.v.) infusion on Day 1, 5-FU 750 mg/m2 by 24-hour continuous i.v. infusion on Days 1-5, and cisplatin 20 mg/m2 by 2-hour i.v. infusion on Days 1-5. Twenty-six patients had measurable disease, and 15 had evaluable disease. All patients were assessable for toxicity.

RESULTS

Twenty-one of the 41 patients (51%; 95% confidence interval [CI], 36.5-65.7%) demonstrated an objective response, including 4 complete responses (10%; 95% CI, 3.9-22.5%). Sixty-five percent of the patients with measurable disease (17 of 26; 95% CI, 58-92.5%) and 27% of the patients with evaluable disease (4 of 15: 95% CI, 11.1-52.3%) achieved a complete response or a partial response. The median response duration was 17 weeks (range, 4-90 weeks), and the median survival duration for all patients was 26 weeks (range, 8 to 118+ weeks). The major toxicity of this treatment was myelosuppression with neutropenia of World Health Organization Grade 3 and 4 in 24% and 10% of the patients, respectively. Nonhematologic toxicity included mucositis, nausea/vomiting, diarrhea, neurotoxicity, and alopecia. Fluid retention occurred in two patients, and one patient had an anaphylatic reaction. Dose reduction was necessary for one patient, because Grade 4 neutropenia and mucositis occurred.

CONCLUSIONS

Paclitaxel, 5-FU, and cisplatin was an active combination regimen in the treatment of advanced gastric carcinoma. The toxicity of this regimen was tolerable. Based on these findings, this combination regimen could be an attractive treatment in the preoperative setting.

Morphologic and biologic changes of experimentally induced cholesteatoma in Mongolian gerbils with anticytokeratin and lectin study

HYPOTHESIS

Aural cholesteatoma has different morphologic and biologic characteristics from the normal epithelial cells.

BACKGROUND

The exact pathophysiology of aural cholesteatoma has not been proved. There are certain factors that can be involved in the development of the aural cholesteatoma, which makes it necessary to find the morphologic and biologic changes in aural cholesteatoma.

METHODS

The animal model of aural cholesteatoma was induced in gerbils with the external auditory canal (EAC) ligation method. Using immunohistochemical method, the distribution of cytokeratin and the binding patterns of lectin were observed to show the biologic and morphologic changes that take place in aural cholesteatomas.

RESULTS

The successful induction rate was 86.7%. The cytokeratin distribution of aural cholesteatoma was similar to that of EAC but different from that of the middle ear mucosa. The cytokeratin distribution in the cholesteatoma did not change with the different duration of EAC ligation. The results of the lectin-binding study indicate that the mucin-type cells are mainly distributed in the suprabasal cells of aural cholesteatoma and that the basal cells of cholesteatoma lack a D-galactosyl sugar residue.

CONCLUSION

This study suggests that the origin of aural cholesteatoma may be the external auditory canal epidermal cells, and the characteristics of these cells do not change once the cholesteatoma develops. This study also suggests that cholesteatoma has different biologic nature from that of the normal epithelial cell, especially in the basal cells.

CDK4 down-regulation induced by paclitaxel is associated with G1 arrest in gastric cancer cells

Paclitaxel induces a cell cycle block at G2-M phase by preventing the depolymerization of microtubules and induces p53-independent apoptosis in many cancer cells. We observed that gastric cancer cells treated with paclitaxel have shown a cyclin-dependent kinase (CDK)4 down-regulation. This paclitaxel-induced CDK4 down-regulation resulted in a cell cycle arrest at G1-S phase. To confirm this observation, we prepared stable transfectants that overexpressed CDK4 and analyzed the cell cycle progression. Ectopic expression of CDK4 in SNU cells resulted in a release of paclitaxel-induced G1 arrest. The release of G1 arrest by enforced expression of CDK4 seems to make the cells more sensitive to paclitaxel-induced apoptosis. From this finding, we could then suggest that paclitaxel treatment induces both G1-S and G2-M blocks in the cell cycle progression of gastric cancer cells.

Synthesis of praziquantel derivatives and their in vitro activity against adult Clonorchis sinensis

Several praziquantel derivatives have been prepared by the acylation of compound 5, and examined on their biological activity in vitro a against adult Clonorchis sinensis collected from rabbits infected with metacercariae which was isolated from Pseudorasbora parva, a second intermediate host, captured in Nakdong river in Korea.

Effect of simultaneous pulsed hyperthermia and pulsed radiation treatment on survival of SiHa cells

Relatively mild temperatures (40-41.5 degrees C) can sensitize human cells to radiation without the development of thermal tolerance to radiosensitization. Therefore there may be a therapeutic benefit to adding mild hyperthermia to brachytherapy regimens for the treatment of cancer. However, the required heating times are long (approximately 48 h) which renders this approach somewhat impractical. A novel alternative is to combine pulsed brachytherapy with pulsed hyperthermia to enable the total radiation dose to be given at an elevated temperature while the total heating time is kept short. A treatment schedule in which 1 Gy radiation pulses were given once per hour during 5-min heating pulses also delivered once per hour, was investigated in vitro in the human cervical carcinoma line, SiHa. The degree of cytotoxicity and thermoradiosensitization of the cells were assessed by cell survival using the colony forming assay. Cells were exposed to pulsed hyperthermia alone (5 min at 45 degrees C, delivered once per hour), acute hyperthermia alone (45 degrees C), pulsed radiation alone (1 Gy per hour), acute radiation alone, and simultaneous pulsed hyperthermia and pulsed radiation. Pulsed heating alone caused little cytotoxicity. However when pulsed heating was added to pulsed radiation, the level of cytotoxicity was greater than for pulsed radiation alone or acute radiation alone. The effect was also greater than would be predicted from a simple additive effect of pulsed radiation and pulsed heating. In conclusion, pulsed heating at 45 degrees C sensitized cells to pulsed radiation without the development of thermal tolerance.

Immunohistochemical analysis of Fas ligand expression in sarcomas. Sarcomas express high level of FasL in vivo

Fas ligand (FasL) and its receptor, Fas, play a key role in the regulation of apoptosis within the immune system. Several prior experimental studies of Fas ligand expression in tumors have suggested a mechanism that enables tumors to evade immune destruction by inducing apoptosis in activated lymphocytes near the tumor cells. Many types of carcinomas have been shown to express FasL, but at present nothing is known about the range of sarcomas capable of expressing FasL in vivo. The aim of this study was to determine the in vivo patterns of FasL expression in human sarcomas. Archival paraffin-embedded tissues of 57 sarcomas and 30 carcinomas were analyzed by immunohistochemistry for the expression of FasL. FasL immunoreactivity was seen in 39 of 57 (68%) sarcomas, including 10 of 10 rhabdomyosarcomas, 5 of 5 malignant schwannomas, 2 of 2 Ewing's sarcomas, 8 of 11 malignant fibrous histiocytomas, 4 of 5 angiosarcomas, 2 of 5 synovial sarcomas, 2 of 5 liposarcomas, 3 of 5 leiomyosarcomas, 2 of 6 osteosarcomas, and 1 of 3 chondrosarcomas. All carcinomas tested (10 gastric adenocarcinomas, 10 hepatocellular carcinomas, and 10 renal cell carcinomas) were positive for FasL. These results demonstrate that FasL expression in sarcomas, although less frequent than in carcinomas, is widespread among the sarcoma types, and suggest that FasL might contribute to the immune escape of sarcomas through killing Fas-bearing lymphocytes.

Contribution of abnormal sarcoplasmic reticulum ATPase activity to systolic and diastolic dysfunction in human heart failure

Two of the most significant characteristics of failing human myocardium are an increased diastolic [Ca2+]i and a prolonged diastolic relaxation. These abnormalities are more pronounced at higher frequencies of stimulation and may be caused by an altered Ca2+ resequestration into the sarcoplasmic reticulum (SR). The force-frequency relationship was determined in multicellular preparations obtained from non-failing (n=6) and failing human myocardium (n=11). The active force in non-failing tissue increased as a function of the frequency of stimulation. In failing myocardium, an increase in frequency of stimulation (>1 Hz) was accompanied by a decrease in active force. Changes in the frequency of stimulation and active force were also associated with changes in intracellular calcium concentrations. The diastolic force in failing myocardium was augmented following an increase in frequency of stimulation, whereas in non-failing tissue, no increase in diastolic force was observed. Associated with the increase in diastolic force was an increase in intracellular diastolic calcium concentrations. The SR Ca2+ ATPase activity was reduced in failing compared to non-failing myocardium. SR Ca2+ ATPase was positively correlated with diastolic force in non-failing myocardium. The relationship between Ca2+ ATPase activity at 1 micromol/l [Ca2+] and active force between 0.5 and 2.0 Hz was different between failing and non-failing myocardium. The diastolic force demonstrate an inverse relationship with the SR Ca2+ ATPase activity in failing myocardium. These data suggest that a reduction in SR Ca2+ ATPase activity contributes to the impairment in both systolic and diastolic function of failing human hearts.

Effects of Ginkgo biloba extract on the cochlear damage induced by local gentamicin installation in guinea pigs

Investigations evaluating the protective effect of Ginkgo biloba extract (EGb) on gentamicin (GM) ototoxicity were undertaken. Guinea pigs treated with 5 mg/kg gentamicin sulfate on the round window niche (RWN) showed acute changes on electrocochleogram and hair cell or microvilli damage on scanning electron microscopy (SEM). There was accumulation of GM in the whole cochlea, especially in the organ of Corti, stria vascularis, and type III fibrocyte on immunohistochemical study. However, the guinea pigs pretreated with local or systemic EGb revealed no significant changes by local GM installation. From these results, we concluded that EGb has a protective effect on the development of GM ototoxicity in the cochlea.

Nickel (II)-induced apoptosis and G2/M enrichment

Treatment with certain DNA-damaging agents induce a complex cellular response comprising pertubation of cell cycle progression and/or apoptosis on proliferating mammalian cells. Our studies were focused on the cellular effects of nickel (II) acetate, DNA-damaging agent, on Chinese hamster ovary (CHO) cells. Fragmented DNAs were examined by agarose gel electrophoresis and cell cycle was determined by DNA flow cytometry using propidium iodide fluorescence. Apparent DNA laddering was observed in cells treated with 240 microM nickel (II) and increased with a concentration-dependent manner. Treatment of nickel (II) acetate resulted in apoptosis which was accompanied by G2/M cell accumulation. Proportion of CHO cells in G2/M phase was also significantly increased in cells exposed to at least 480 microM nickel (II) from 57.7% of cells in the G0/G1 phase, 34.7% in the S phase, and 7.6% in the G2/M1 phase for 0 microM nickel (II), to 58.6%, 14.5%, and 26.9% for 640 microM nickel (II). These findings suggest that nickel (II) can modulate cellular response through some common effectors involving in both apoptotic and cell cycle regulatory pathways.

Effect of supplemental beta-carotene on plasma concentrations of carotenoids, retinol, and alpha-tocopherol in humans

High doses of beta-carotene, a lipid-soluble nutrient, may affect the plasma concentrations of other lipid-soluble nutrients. The purpose of this study was to assess the effects of long-term daily supplementation with beta-carotene (50 mg/d) on circulating concentrations of other carotenoids, retinol, and alpha-tocopherol over time. Data were available from 259 men and women participating in the Carotene Prevention Trial, a 2-center chemoprevention trial designed to determine whether supplemental beta-carotene can prevent second malignant tumors in patients cured of an early stage cancer of the oral cavity, pharynx, or larynx. Up to 2 blood samples were obtained before the intervention (before and after a 1-mo placebo run-in), with postrandomization samples obtained at 3, 12, 24, 36, 48, and 60 mo. Supplementation with beta-carotene produced a persistent 9- to 10-fold increase in median plasma beta-carotene concentrations (225 nmol/L at baseline to 2255 nmol/L at 3 mo) and a persistent 2-fold increase in median plasma alpha-carotene concentrations (45 nmol/L at baseline to 95 nmol/L at 3 mo). Concentrations of retinol, alpha-tocopherol, lycopene, and lutein/zeaxanthin were not affected by supplemental beta-carotene. Up to 5 y of daily supplementation with beta-carotene increased circulating concentrations of alpha- and beta-carotene, but did not alter concentrations of lycopene, lutein/zeaxanthin, retinol, or alpha-tocopherol.

Frequent somatic mutations in serine/threonine kinase 11/Peutz-Jeghers syndrome gene in left-sided colon cancer

We analyzed somatic mutation and loss of heterozygosity (LOH) in the serine/threonine kinase 11 (STK11)/Peutz-Jeghers syndrome gene in 49 colorectal tumors in three different stages of a dysplasia-carcinoma sequence. We detected LOH in 10 of 19 (52.6%) informative colorectal cancers at loci D19S886 and/or D19S883, but no LOH was observed in 25 informative adenomas. We detected a total of 9 somatic mutations [7 of 13 (53.8%) left-sided colon cancers and 2 of 7 (28.6%) left-sided adenomas with high-grade dysplasia], but no mutations were detected in right-sided colon tumors. Of the nine mutations, one was a frameshift mutation (the same mutation detected in Peutz-Jeghers syndrome family previously), and the other eight were missense mutations. This results indicate that STK11 is a tumor suppressor gene and that genetic changes of STK11 play an important role in left-sided colon cancer carcinogenesis.

Quantitative low-dose assessment of seafood toxin, domoic acid, in the rat brain: application of physiologically-based pharmacokinetic (PBPK) modeling

The purpose of this study was to construct a physiologically based pharmacokinetic model and demonstrate its ability to predict low-dose uptake of domoic acid, a seafood contaminant, in discrete areas of the rat brain. The model we used was derived from the generic PBPK model of our previous studies with 2,4-dichlorophenoxyacetic acid (Kim et al., 1994. Pharmacokinetic modeling of 2,4-dichlorophenoxyacetic acid (2,4-D) in rats and in rabbits brain following single dose administration. Toxicol. Lett. 74, 189; Kim et al., 1995. Development of a physiologically based pharmacokinetic model for 2,4-dichlorophenoxyacetic acid dosimetry in discrete areas of the rabbit brain. Neurotoxicol. Teratol. 17, 111), to which physiological- and chemical-specific parameters for domoic acid were applied. It incorporates two body compartments along with compartments for venous and arterial blood, cerebrospinal fluid, brain plasma and seven brain regions. Uptake of the blood-borne toxin is membrane-limited by the blood-brain barrier with clearance from the brain provided by cerebrospinal fluid `sink' mechanisms. This model generated predicted profiles of toxin level in brain and blood over a 1-h period that compared reasonably well with concentrations calculated from in vivo data of rats that had been given [(3)H]domoic acid intravenously (Preston and Hynie, 1991. Transfer constants for blood-brain barrier permeation of the neuroexcitatory shellfish toxin, domoic acid. Can. J. Neurol. Sci. 18, 39). This PBPK model should be an effective tool for evaluating the target doses that produce the potential neurotoxicity of domoic acid found in foods.

Fas ligand is expressed in normal skin and in some cutaneous malignancies

Fas, a cell surface receptor and member of the tumour necrosis factor receptor superfamily, induces apoptosis upon oligomerization by its ligand (Fas ligand: FasL). Detailed studies have revealed that Fas is broadly expressed in normal human tissues, but relatively little is known about the range of cell types capable of expressing FasL. The aim of this study was to determine the in vivo patterns of expression of Fas and FasL in human skin tissues. Immunohistochemistry was performed using paraffin-embedded samples of normal and neoplastic skin tissues. In normal skin, FasL was expressed in the epidermis, sebaceous glands, sweat glands and outer root sheath of the hair. In squamous cell carcinomas (SCC), all cases analysed expressed FasL at high levels, whereas 60% of basal cell carcinomas (BCC) were positive for FasL. Expression of Fas in normal skin was observed in the basal and spinous layers of the epidermis, the outer root sheath of the hair, and the sebaceous glands. Expression of Fas was observed in all the SCC tested and none of the BCC tested. Expression of FasL by normal cells and tumour cells in skin tissue, demonstrated for the first time in the present study, may provide an important clue to understanding skin physiology, and immune evasion of skin tumours.

Control of intraoperative bleeding with hydrostatic pressure during endoscopic surgery

Though intracranial endoscopic surgery has several advantages, poor visibility caused by bleeding from the operative field is one of its limitations. In two cases involving endoscopic III ventriculostomy the authors encountered moderate bleeding, and this was controlled with 'water column tamponade.' Following the application of hydrostatic pressure of 40-50 cmH2O for less than 2 min, the bleeding temporarily stopped and the operative field became clear. Several applications of this tamponade made it possible to complete the procedures. Although the pressure applied by the water column was not high enough to disturb the cerebrovascular autoregulation, blood pressure rose significantly during application of the water column tamponade. This method was valuable for the completion of procedures when bleeding was not at high pressure from large arteries. Careful monitoring of the blood pressure is mandatory, and adjustment of the pressure applied will make the procedure safer.

Regional deposition of inhaled particles in human lungs: comparison between men and women

We measured detailed regional deposition patterns of inhaled particles in healthy adult male (n = 11; 25 +/- 4 yr of age) and female (n = 11; 25 +/- 3 yr of age) subjects by means of a serial bolus aerosol delivery technique for monodisperse fine [particle diameter (Dp) = 1 micron] and coarse aerosols (Dp = 3 and 5 micron). The bolus aerosol (40 ml half-width) was delivered to a specific volumetric depth (Vp) of the lung ranging from 100 to 500 ml with a 50-ml increment, and local deposition fraction (LDF) was assessed for each of the 10 local volumetric regions. In all subjects, the deposition distribution pattern was very uneven with respect to Vp, showing characteristic unimodal curves with respect to particle size and flow rate. However, the unevenness was more pronounced in women. LDF tended to be greater in all regions of the lung in women than in men for Dp = 1 micron. For Dp = 3 and 5 micron, LDF showed a marked enhancement in the shallow region of Vp </= 200 ml in women compared with men (P < 0.05). LDF in women was comparable to or smaller than those of men in deep lung regions of Vp > 200 ml. Total lung deposition was comparable between men and women for fine particles but was consistently greater in women than men for coarse particles regardless of flow rates used: the difference ranged from 9 to 31% and was greater with higher flow rates (P < 0.05). The results indicate that 1) particle deposition characteristics differ between healthy men and women under controlled breathing conditions and 2) deposition in women is greater than that in men.