Phosphoinositide-specific phospholipase C interacts with phosphatidylinositol kinase homolog TOR2

The Saccharomyces cerevisiae PLC1 gene encodes a homolog of the delta isoform of mammalian phosphoinositide-specific phospholipase C. Cells deleted for PLC1 gene (plc1Delta) are viable but display several phenotypes, including temperature and osmotic sensitivity and defects in utilization of carbon sources other than glucose. We have used the two hybrid screen to identify Plc1p-interacting proteins. One of the identified proteins was Tor2p, a putative phosphatidylinositol (PtdIns) kinase involved in regulation of protein synthesis, cell cycle progression and organization of the actin cytoskeleton. This interaction was confirmed biochemically by coprecipitation of Plc1p and Tor2p. The results suggest that Tor2p, as a PtdIns kinase, produces phosphorylated PtdIns, which is then hydrolyzed by the associated Plc1p. The proximity of Tor2p to Plc1p may therefore result in a regulated spatial and temporal coupling of synthesis and hydrolysis of phosphorylated forms of PtdIns.

A novel membrane-bound glutathione S-transferase functions in the stationary phase of the yeast Saccharomyces cerevisiae

The glutathione S-transferases (GSTs) represent a significant group of detoxification enzymes that play an important role in drug resistance in all eukaryotic species. In this paper we report an identification and characterization of the two Saccharomyces cerevisiae genes, GTT1 and GTT2 (glutathione transferase 1 and 2), coding for functional GST enzymes. Despite only limited similarity with GSTs from other organisms (approximately 50%), recombinant Gtt1p and Gtt2p exhibit GST activity with 1-chloro-2, 4-dinitrobenzene as a substrate. Both Gtt1p and Gtt2p are able to form homodimers, as determined by two hybrid assay. Subcellular fractionation demonstrated that Gtt1p associates with the endoplasmic reticulum. Expression of GTT1 is induced after diauxic shift and remains high throughout the stationary phase. Strains deleted for GTT1 and/or GTT2 are viable but exhibit increased sensitivity to heat shock in stationary phase and limited ability to grow at 39 degreesC.

Eosinophilic pustular folliculitis (Ofuji's disease) in myelodysplastic syndrome

We describe a case of eosinophilic pustular folliculitis (EPF, Ofuji's disease) in a 12-year-old male who suffered from myelodysplastic syndrome. Bone marrow study revealed an increase in the eosinophil cell line without peripheral blood eosinophilia in our case. We suggest that the immunologic abberations ascribed to myelodysplastic syndrome and the increase in the eosinophil cell line in the bone marrow might play roles in the development of EPF in our case.

Effects of green tea catechin on hepatic microsomal phospholipase A2 activities and changes of hepatic phospholipid species in streptozotocin-induced diabetic rats

In this study, male Sprague-Dawley rats weighing 70 +/- 5 g were divided into a control (normal) group and three different diabetes mellitus (DM) groups that were supplemented with catechin-free (DM-0C), 0.5% catechin dietary (DM-0.5C), and 1% catechin (DM-1.0C). The animals were maintained on an experimental diet for four weeks. At this point, they were injected with streptozotocin (STZ) to induce diabetes, and they were sacrificed on the 6th day to determine the activities of phospholipase A2 (PLA2) and the changes of phospholipid species by catechin supplementation. In liver tissues, no significant differences were found between the PC hydrolysis of a normal group and a diabetic group; however, PE hydrolysis of the DM-0C, DM-0.5C, and DM-1.0C groups increased by 68.9%, 34.01%, and 26.9%, respectively, compared with the normal group. Although the PLA2 activity of the DM-0C group in the liver tissues increased 91% compared with the normal group, the PLA2 activity of DM-0.5C and DM-1.0C, which were fed catechin, increased 50% and 56%, respectively, compared with the normal group. In the liver tissues, peroxide values of the DM-0C, the DM-0.5C, and the DM-1.0C groups were increased 109%, 32.8%, and 46.7%, respectively, compared with the normal group. Based on these results for STZ-induced diabetic rats, lipid peroxidation seems to be accelerated specifically with the increased PLA2 activities. Thus if antioxidants like catechin were supplementation, the activity of PLA2 and PE hydrolysis can be altered and the accumulation of lipid peroxide would be decreased. Therefore we concluded that the antioxidant catechin for diabetic animals can significantly reduce PLA2 activities and lipid peroxide formation.

Alpha-fetoprotein-producing gastric cancer

We measured the sero-positivity rate of serum alpha-fetoprotein (alphaFP) of gastric cancer patients by ELISA assay; forty-two curatively resected patients, 14 palliatively resected patients, 8 who received explo-laparotomy or bypass surgery and 18 patients with systemic metastasis. The sero-positive rate was 9.8% (8/82) and the positivity increased with cancer progression. Sex, age and pathological type were similar between alphaFP-positive and -negative patients. The overall synchronous hepatic metastasis rates in alphaFP-positive and alphaFP-negative groups were 37.5% (3/8) and 12.2% (9/74), respectively (p=0.08). The predictability of synchronous liver metastasis in eight alphaFP-positive patients were as follows: 37. 5% of total patients (3/8), 50.0% (3/6) of unresectable patients, and 60.0% (3/5) of patients with systemic metastasis. In three alphaFP-positive patient with liver metastasis, all the hepatic lesions were intrahepatic and multiple, while in alphaFP-negative patients, 67% (6/9) of the hepatic lesions was single intrahepatic lesion or surface nodule. The predictability of both synchronous and metachronous liver metastasis in alphaFP-positive gastric cancer patients was 75%. These findings suggested that, in advanced stomach cancer patients, especially in stage IV, alphaFP can be used in predicting liver metastasis during follow-up.

The induction of P450-mediated oxidation of all-trans retinoic acid by retinoids in head and neck squamous cell carcinoma cell lines

All-trans retinoic acid (RA) can be catabolized into polar metabolites by cytochrome P450 (P450) in several tissues including the skin. We examined eight different squamous cell carcinoma (SCC) cell lines to determine their capacity to induce P450-mediated oxidation of RA. Among the eight different cell lines, enhanced catabolism was detected in AMC-HN-1, -2, -5, and -6, whereas it was not found in the cell lines of AMC-HN-3, -4, -7, and -8. It was found that the enhanced catabolism brought on by P450 induction was blocked when RA was added to AMC-HN-6 along with actinomycin D or cyclohexamide. Also, this catabolism was inhibited by ketoconazole. P450-mediated oxidation was detectable within 4 hours of RA treatment, and RA catabolism reached its maximum 16 hours after treatment. P450 was induced by 13-cis-RA, 9-cis-RA, and retinal; however, retinol could not induce P450. In conclusion, P450 can be induced by retinoids in head and neck SCC (HNSCC) cells and the ability of retinoids to induce P450 can serve as an important factor in determining the biological effect of retinoids.

Effect of hyperglycemia on brain cell membrane function and energy metabolism during hypoxia-ischemia in newborn piglets

The purpose of this study was to test the hypothesis that hyperglycemia ameliorates changes in brain cell membrane function and preserves cerebral high energy phosphates during hypoxia-ischemia in newborn piglets. A total of 42 ventilated piglets were divided into 4 groups, normoglycemic/normoxic(group 1, n=9), hyperglycemic/normoxic(group 2, n=8), normoglycemic/hypoxic-ischemic(group 3, n=13) and hyperglycemic/hypoxic-ischemic(group 4, n=12) group. Cerebral hypoxia-ischemia was induced by occlusion of bilateral common carotid arteries and simultaneous breathing with 8% oxygen for 30 min. Hyperglycemia (blood glucose 350-400 mg/dl) was maintained for 90 min before and throughout hypoxia-ischemia using modified glucose clamp technique. Changes in cytochrome aa3 were continuously monitored using near infrared spectroscopy. Blood and CSF glucose and lactate were monitored. Na+, K+-ATPase activity, lipid peroxidation products (conjugated dienes), tissue high energy phosphates (ATP and phosphocreatine) levels and brain glucose and lactate levels were determined biochemically in the cerebral cortex. During hypoxia-ischemia, glucose levels in blood and CSF were significantly elevated in hyperglycemic/hypoxic-ischemic group compared with normoglycemic/hypoxic-ischemic group, but lactate levels in blood and CSF were not different between two groups. At the end of hypoxia-ischemia of group 3 and 4, triangle up Cyt aa3, Na+, K+-ATPase activity, ATP and phosphocreatine values in brain were significantly decreased compared with normoxic groups 1 and 2, but were not different between groups 3 and 4. Levels of conjugated dienes and brain lactate were significantly increased in groups 3 and 4 compared with groups 1 and 2, and were significantly elevated in group 4 than in group 3 (0.30+/-0.11 vs. 0.09+/-0.02 micromol g-1 protein, 26.4+/-7.6 vs. 13.1+/-2.6 mmol kg-1, p<0.05). These findings suggest that hyperglycemia does not reduce the changes in brain cell membrane function and does not preserve cerebral high energy phosphates during hypoxia-ischemia in newborn piglets. We speculate that hyperglycemia may be harmful during hypoxia-ischemia due to increased levels of lipid peroxidation in newborn piglet.

A case of arteriovenous type cardiac hemangioma

Cardiac hemangiomas are rare primary tumors of the heart and constitute only 2.8% of primary cardiac tumors. They are classified into capillary, cavernous, epitheloid and arteriovenous type and the last one is the most uncommon type. We experienced a case of cardiac hemangioma which was diagnosed as arteriovenous type for the first time in Korea in the literature. The patient was a 54-year-old woman who presented with palpitation and anterior chest pain. The diagnosis was based upon coronary angiography which showed two tumor blushings located in the interatrial and interventricular septum with venous drainage to the coronary sinus and right atrium. Associated atrial fibrillation with rapid ventricular response was controlled with digitalis.

Cutaneous mesenchymal hamartoma on the foot

We report a 16-year-old man with a cutaneous mesenchymal hamartoma on the left foot since infancy. Clinically, the lesion was 10x6 cm in size, relatively ill-defined, skin colored, and comprised of confluent nodules. Histopathologic examination revealed histology compatible with cutaneous mesenchymal hamartoma.

Diagnostic pitfalls of Merkel cell carcinoma and dramatic response to chemotherapy

Merkel cell carcinoma (MCC) is an unusual malignant tumor that arises from neuroendocrine cells with features of epithelial differentiation. We describe a MCC patient with unusual clinical, histopathological, and immunohistochemical features. Although the microscopic, immunohistochemical, and ultrastructural characteristics of MCC have been well defined, diagnostic difficulties remain, particularly in distinguishing it from lymphoma involving the skin, as suggested by our case. This is an unusual case in which dense lymphoid infiltration masked the true tumor. All the immunohistochemical markers of MCC except neuron-specific enolase (NSE) were negative. The dramatic response to primary chemotherapy was also very noteworthy.

Four cases of pustulotic arthro-osteitis

We describe four cases of pustulotic arthro-osteitis. All of them suffered from anterior chest wall symptoms, such as swelling and pain on the sternoclavicular joint, sternal angle area, sternocostal joint, and costochondral junction. Although chest X-ray findings were all normal, 99mTc-scintigraphy revealed increased uptake in the affected areas in all cases. Laboratory examinations including rheumatoid factor were negative or normal except for elevation of the erythrocyte sedimentation rate and C-reactive protein in 2 cases. After treatment with non-steroidal anti-inflammatory drugs and etretinate or topical PUVA, the skin lesions on the palms and soles and the arthro-osteitis were moderately improved. Pustulotic arthro-osteitis should be considered when a patient with pustulosis palmoplantaris complains of anterior chest wall pain and other joint pain.

Increased serum levels of transforming growth factor-alpha in patients with colorectal cancer

PURPOSE

This study was conducted to investigate the serum levels of transforming growth factor-alpha in patients with colorectal cancer and to investigate the clinical significance of these levels in association with tumor stage and histologic differentiation. Also, serum levels of transforming growth factor-alpha were measured after curative surgical resection.

METHODS

Serum levels of transforming growth factor-alpha were measured in 42 consecutive patients with colorectal cancer before surgery, in 21 patients after surgical resection (part of the 42 preoperative patients), and in 20 healthy volunteers. We used TGF-alpha Assay.

RESULTS

Serum levels of transforming growth factor-alpha in patients with colorectal cancer were significantly higher than in the healthy control group (P = 0.001). Significant elevations in serum levels of transforming growth factor-alpha were found in 50 percent (21/42) of patients with colorectal cancer when the mean + 2 standard deviations (80.4 pg/ml) of the control group were used as the upper limit of the normal range. Serum levels of transforming growth factor-alpha tended to decrease with increasing tumor size (n = 31; r = -0.52; P = 0.002). Serum levels of transforming growth factor-alpha before surgery (89.7 +/- 44.4 pg/ml; n = 21) significantly decreased to 60.3 +/- 19.8 pg/ml after surgical resections of tumors (P = 0.017). Serum levels of transforming growth factor-alpha completely decreased to the same serum levels of the control group after surgical resections in all patients who had serum levels of transforming growth factor-alpha greater than mean + 2 standard deviations (80.4 pg/ml) of the control group preoperatively (n = 11; P = 0.002).

CONCLUSIONS

Levels of preoperative transforming growth factor-alpha in patients with colorectal cancer appeared to be higher than levels measured in control subjects. Serum levels of transforming growth factor-alpha before surgery significantly decreased after surgical resections of tumors. Additional studies are warranted to determine if serum levels of transforming growth factor-alpha may be useful as a potential biomarker in the management of patients with colorectal cancer.

Increased serum levels of mutant p53 proteins in patients with colorectal cancer

We have examined the serum levels of the mutant p53 protein in patients with colorectal cancer preoperatively (n=50), and in patients with adenomatous polyp (n=13). Mutant p53 protein in patients after curative surgical resection of colorectal cancer (n=26, part of the fifty preoperative patients) was also measured. Serum samples were stored frozen at -70 degrees C until the time of analysis. We used the p53 mutant ELISA (QIA03, CALBIOCHEM) system. Serum levels of the mutant p53 protein in patients with colorectal cancer (mean=0.97+/-0.14 ng/ml, ranged from 0.7 ng/ml to 1.37 ng/ml, n=50) were significantly greater than those in patients with adenomatous polyp (mean=0.73+/-0.06 ng/ml, ranged from 0.69 ng/ml to 0.83 ng/ml) (p<0.001). There was a significant correlation between serum p53 levels and CA19-9 levels (p<0.01). Serum levels of the mutant p53 protein prior to surgery (mean=0.97+/-0.13 ng/ml, n=26) significantly decreased after surgical resection of tumor (mean=0.82+/-0.07 ng/ml) (p<0.001, paired t-test). These results suggest that mutant p53 protein might be used as a potential biomarker in the management of patients with colorectal cancer. Further study is warranted to establish its clinical significance.

Calcipotriene-induced improvement in psoriasis is associated with reduced interleukin-8 and increased interleukin-10 levels within lesions

Calcipotriene is a synthetic analogue of 1,25-dihydroxyvitamin D3 established to be effective topically in the treatment of psoriasis. We investigated the early cellular and immunological events induced by calcipotriene in psoriasis. Thirty patients with moderate plaque-type psoriasis were randomly assigned to receive twice daily applications of either calcipotriene ointment 0.005% or matching vehicle for 6 weeks. Skin biopsies (6 mm) were performed from designated plaques at baseline and days 3 and 7. On these days and at weeks 2, 4 and 6, complete clinical evaluations were made in a double-blind fashion. Consistent with previous studies, significant clinical improvement (P < 0.05) in psoriasis was observed in patients receiving calcipotriene vs. those receiving vehicle by day 7 for scale and erythema, and by day 14 for thickness. No significant improvement, however, was seen on day 3. None of the immunohistological markers (CD1a, CD4, CD8, ICAM-1, VCAM-1, E-selectin, HLA-DR) semiquantitatively assessed in psoriatic plaques was significantly changed by calcipotriene treatment for 7 days. In the calcipotriene-treated group, interleukin (IL)-10 levels (pg/microgram of protein) increased by 57% from baseline (0.030 +/- 0.006; mean +/- SEM) to day 3 (0.047 +/- 0.011) (P = 0.05 vs. baseline; n = 10) and remained elevated at day 7 (0.046 +/- 0.012). IL-8 levels (pg/microgram of protein), however, declined by 70% from baseline (0.13 +/- 0.06) to day 3 (0.04 +/- 0.01), and remained low at day 7 (0.03 +/- 0.02) (P < 0.05 vs. baseline; n = 10). Both IL-8 and IL-10 were unaffected by vehicle treatment. Calcipotriene-induced clinical improvement of psoriasis is preceded by an increase in IL-10 and a concomitant decrease in IL-8 levels. The changes in the level of these two cytokines provide further evidence for immunological changes as a significant part of the mechanism of action of calcipotriene in psoriasis.

Molecular epidemiological analysis of quinolone-resistant Escherichia coli causing bacteremia in neutropenic patients with leukemia in Korea

We analyzed an outbreak of Escherichia coli bacteremia in eight patients with leukemia in a hematology-oncology unit from July to September 1994. The antibiograms and genotypic patterns of the isolates were different, thus suggesting that the outbreak did not originate from a single clone. However, all the isolates were resistant to quinolones, which led us to examine the microbiological records from 1992 to 1994. The incidence of quinolone-resistant E. coli bacteremia in the hematology-oncology unit ranged from 81.8% to 94.6% during this period. We then analyzed 36 more isolates recovered from late 1994 to 1995. Field inversion gel electrophoresis patterns of these isolates were also different. Analysis of the quinolone resistance determining region in gyrA revealed that all the isolates had a double mutation in gyrA. In conclusion, quinolone-resistant E. coli could be an emerging threat to neutropenic patients with leukemia who receive a quinolone prophylactically, and attention must be paid to this trend of resistance.

Involvement of nuclear factor-kappa B in platelet-activating factor-mediated tumor necrosis factor-alpha expression

Tumor necrosis factor (TNF)-alpha and platelet-activating factor (PAF) are important mediators of inflammatory reactions, and their release is controlled by a positive feedback network. However, the regulatory mechanisms underlying the interaction of these two molecules are unknown. Within 10 min of the injection of lipopolysaccharide (LPS) into C57BL/6 mice, effects inducible by PAF such as anaphylactic shock-like symptoms, disseminated intravascular coagulation, and hemorrhage in renal medullae were observed, and all these pathological changes were prevented by the PAF antagonist, BN 50739. The plasma level of PAF after LPS injection reached a peak at 5 min. TNF-alpha gene expression was evident 20 min after LPS injection and was maximal at 40 min, and the level of serum TNF-alpha reached a peak at 1 h. Pretreatment with BN 50739 inhibited LPS-induced TNF-alpha gene expression and protein synthesis in a dose-dependent manner. Injection of PAF or treatment of the macrophage cell line, J774A.1, with PAF activated the transcription factor, nuclear factor (NF)-kappa B, which is essential for inducible TNF-alpha transcription. The activation of NF-kappa B by PAF preceded the LPS-mediated TNF-alpha gene expression. Pretreatment with BN 50739 inhibited LPS-induced mobilization of NF-kappa B in a dose-dependent manner in vivo as well as in vitro. These data suggest that PAF, which is released immediately or shortly after LPS injection, induces the expression of TNF-alpha through the activation of NF-kappa B.

A case of hidroacanthoma simplex

There are many conditions characterized by nests of cells within the epidermis. One of them, hidroacanthoma simplex, has been regarded as an epidermal tumor differentiating to intraepidermal eccrine duct cell. We report a case of hidroacanthoma simplex with the results of immunohistochemical study. Staining for 35 beta H11 (reacting with keratin No. 8), 35 beta E12 (reacting with keratin No. 1, 5, 10, 11), S-100 protein, and CEA was negative in the tumor cell nests; these monoclonal antibodies stained the nests of eccrine poroma.

Apoptosis is induced by anti-Fas antibody alone in cultured human keratinocytes

Fas is a well-known cell surface receptor whose main function is the induction of apoptosis in many cell types including human keratinocytes. Several reports indicate that anti-Fas antibody can induce apoptosis in cultured keratinocytes after interferon gamma (IFN gamma) pretreatment. Because IFN gamma is synthesized by activated T cells, but not by keratinocytes, these results suggest that Fas may only be effective in apoptosis occurring in T-cell mediated inflammatory skin diseases. We hypothesized that Fas alone might mediate apoptosis in normal human keratinocytes without any other help and thus play a role in normal epidermal homeostasis. By using Cell Death Detection ELISA, we observed keratinocyte apoptosis 24 hours after anti-Fas antibody stimulation not only in IFN gamma-pretreated conditions but also in non-pretreated conditions. Even though the percentage of cultured keratinocytes stained by anti-Fas antibody increased from 7.8 to 25.8% 24 hours after IFN gamma stimulation, the apoptotic rate of the anti-Fas only group was the same as that of the anti-Fas plus IFN gamma treated group. In both conditions, we have verified apoptotic phenomena in cultured keratinocytes in situ by TUNEL staining. Some apoptotic bodies were phagocytosed by neighboring keratinocytes. Fas-mediated apoptosis was not inhibited by the protein synthesis inhibitor cycloheximide and was enhanced by inhibitors of several protein kinases, including PKC and staurosporine. These results suggest that Fas-mediated apoptosis may play a role in both T cell-mediated skin diseases and normal epidermal homeostasis.

Reduction in post-intubation respiratory resistance by isoflurane and albuterol

PURPOSE

This study examined the bronchodilating effects of 0.6 MAC and 1.1 MAC isoflurane (ISF) on respiratory system resistance (Rrs) following tracheal intubation and determined whether albuterol supplements that effect.

METHODS

Sixty-seven adult patients were anaesthetized with 2 micrograms.kg-1 fentanyl and 5 mg.kg-1 thiopentone and their tracheas intubated following administration of 1 mg.kg-1 succinylcholine. Respiratory system resistance was measured following intubation and the patients then randomized to receive either 1.1 MAC ISF in oxygen or 0.6 MAC ISF in 50% nitrous oxide and oxygen. Ten minutes later, Rrs was again measured. Patients were then further randomized to receive albuterol or a placebo using incremental doses of 2, 5, and 10 puffs (albuterol puff = 90 micrograms) delivered via a metered dose inhaler at ten minute intervals.

RESULTS

Isoflurane at 1.1 MAC decreased post-intubation Rrs by 23 +/- 5% (mean +/- sem) whereas the decrease was only 7 +/- 5% for 0.6 MAC ISF (P < 0.01). Two puffs of albuterol resulted in a further decrease of 12 +/- 3% (mean +/- sem) in Rrs compared with a 2 +/- 4% decrease in the placebo groups (P < 0.05). Additional puffs of albuterol resulted in no further changes in Rrs.

CONCLUSION

We conclude that following tracheal intubation the reduction in Rrs produced by ISF is highly concentration dependent. Albuterol results in a small further reduction in Rrs.