Properties of Ca(2+)-dependent K+ channels of human gingival fibroblasts

Cells in the oral cavity are normally exposed to different temperatures. Ion transport systems are influenced by temperature in other tissues: In particular, changes in intracellular K+ ion can affect cell growth and synthesis of macromolecules. The purpose of this investigation was to identify K+ channels in human gingival fibroblast cells and analyze the effect of temperature on their K+ conduction properties. Ca(2+)-dependent K+ channels with a large conductance (125 pS in symmetrical K(+)-rich solutions) were identified in human gingival fibroblasts and studied by the patch-clamp technique. The open probability of the channels varied with membrane potential between +40 and -100 mV. When the bath temperature was decreased from 40 to 4 degrees C, channel conductance was reduced, but the mean open time of the channels was increased. The activation energies for the conductance and the reciprocal of the mean open time were estimated to be 9.1 and 22.9 kJ/mol, respectively. These values are lower than those reported for these and other types of channels in cells from other tissues. The open probability of the channels was nearly constant in the temperature range studied. These results suggest that the properties of Ca(2+)-dependent K+ channels of gingival fibroblasts remain relatively unchanged when the cells are exposed to a wide range of temperatures.

A case with quadruple primary cancers of head and neck

Despite progress in techniques for early detection and treatment of cancers, cases of multiple primary cancers are apparently increasing. This paper reported quadruple primary cancers of stomach, lung, hypopharynx and maxillary sinus in a 63-year-old male. He finally died of brain metastasis and pneumonia by MRSA (Me Resistant S. aureus).

[A neonate case of dural arteriovenous shunt presenting with cerebellar hemorrhage]

A rare case of dural arteriovenous shunt (dAVS) manifested as cerebellar hemorrhage in a neonate is reported. Seven days after birth, a neonate was referred to our hospital because of consciousness disturbance. CT scan revealed cerebellar hemorrhage, subarachnoid hemorrhage, subdural hematoma, and a high density mass lesion at the torcular herophili. Retrograde brachial angiogram failed to show any vascular lesions. He underwent an evacuation of the cerebellar hematoma. Postoperative course was uneventful. However, at the age of four months, he was admitted again because of consciousness disturbance and cardiac failure. CT scan revealed hydrocephalus and an enlarged mass lesion at the torcular herophili. Angiogram disclosed dural AVS. Its feeding arteries were as follows; the bilateral middle meningeal arteries (MMA), the occipital arteries (OA), dural branches of the bilateral posterior inferior cerebellar arteries, arteries consisting of transdural anastomosis from the left posterior cerebral artery. The arterial flow from these feeding arteries was shunting directly to the torcular herophili, the posterior part of the superior sagittal sinus, and the straight sinus. He underwent a venticulo-peritoneal shunting. Then, after treatment for cardiac failure, superselective embolization of the bilateral MMAs and the OAs resulted in diminution of shunting flow. The initial onset of this case was at seven days after his birth. Dural AVS is very rare in the pediatric population, particularly in the neonate. The clinical features, pathogenesis, and the treatment for this rare entity are discussed.

Percutaneous transluminal angioplasty in a canine model of cerebral vasospasm: angiographic, histologic, and pharmacologic evaluation

BACKGROUND

Cerebral vasospasm following subarachnoid hemorrhage (SAH) is one of the leading factors that deteriorate the clinical outcome after aneurysmal surgery. Percutaneous transluminal angioplasty (PTA) is a method to directly dilate the constricted vessel using the intravascular neurosurgical technique.

METHODS

Angiographic, histologic, and pharmacologic evaluations related to PTA are presented, using a canine double-injection model of SAH. In angiographic evaluation, we studied the effect of PTA performed on day 1, 4, or 7 of SAH. We performed sequential histologic study by light microscopy using the same for the angiographic evaluation. In pharmacologic evaluation, we measured in vitro isotonic constrictive force using two vasoconstrictors immediately after PTA on normal basilar arteries (control group) and basilar arteries on day 7 of SAH.

RESULTS

In angiographic evaluation, we observed the effective dilation of spastic artery immediately after PTA and saw no recurrence of vessel constriction when PTA was performed on day 7 of SAH. However, the preventive effect of PTA was inconsistent when it was performed earlier after SAH (days 1, 4). In histologic evaluation, PTA segments immediately after PTA showed denuding of endothelial cells and stretching of the internal elastic lamina without disruption of the muscle layer. In pharmacologic evaluation, there was no difference in isotonic constrictive force created by vasoconstrictors between the PTA and non-PTA segments without SAH. However, there was a statistically significant reduction of isotonic constrictive force on the PTA segment with SAH.

CONCLUSIONS

We suggest that the mechanism of PTA vasodilation in vasospasm after SAH may result from mild functional changes in the vascular wall when PTA was applied on day 7 of SAH. The functional changes would not be adequately induced to prevent recurrence of vasoconstriction when PTA was applied soon after SAH.

Sjögren's syndrome with pleural effusion

Sjögren's syndrome (Sjs) can cause many organic changes, but is rarely accompanied by pleuritis. We report here a 62-year-old patient with subclinical Sjs who developed unilateral pleuritis with moderate effusion. He was diagnosed to have subclinical Sjs based on the positivity of anti SS-A/SS-B antibodies and the biopsy findings of minor salivary glands which revealed lymphocyte infiltration around the duct. In the pleural effusion, both increased lymphocytes and anti SS-A/SS-B antibodies were observed. He showed no signs of infection nor malignancy. There was no direct evidence that he had other collagen diseases which cause pleuritis. We conclude that the pleuritis was caused by Sjs. In patients with Sjs, activated polyclonal B lymphocytes and autoantibodies are considered to cause systemic tissue damage. This case indicates that these factors can cause pleuritis in Sjs patients.

Detection of superoxide free radicals in rats with acute pancreatitis

To study the importance of oxygen-derived free radicals in acute pancreatitis, an experimental study of in vivo detection of superoxide free radicals (O2-) was performed using rats. Using a new chemiluminescence probe (2-methyl-6-[p-methoxyphenyl]-3,7-dihydro-imidazol[1,2-1]pyrazin- 3-one; MCLA; a Cypridina luciferin analogue) and a highly sensitive photon counting system, O2- from the pancreatic surface of rats with experimental acute pancreatitis induced by 180 micrograms cerulein/kg was detected. The time course of MCLA-dependent luminescence suggested that O2- production began 2-3 h after cerulein injection and then decreased gradually. Superoxide free radical production in the pancreas of rats with cerulein-induced acute pancreatitis was confirmed using MCLA-dependent chemiluminescence. This new method allows direct observation of the behavior of oxygen-derived free radicals.

Treatment of a stage I testicular yolk sac tumor with vascular invasion

There is controversy concerning the treatment of stage I yolk sac tumor of the testis, particularly of those with histological factors that indicate a high risk of relapse. Usually orchiectomy alone is sufficient and adjuvant chemotherapy is unnecessary. Retroperitoneal lymphadenectomy is indicated for patients with persistently high alpha-fetoprotein. Once recurred, treatment at that time is thought to be curative. However, postoperative chemotherapy may be necessary for patients with a tumor expressing histological factors that predict possible relapse. In this paper we report on a case of a 2 year old boy whose tumor invaded the testicular veins. The patient suffered from recurrent disease but was successfully treated by chemotherapeutic regimens including cisplatin and retroperitoneal lymphadenectomy. The importance of the histological factors in making a decision on the treatment strategy for stage I testicular yolk sac tumor is discussed.

Positive and negative regulation of granulocyte-macrophage colony-stimulating factor promoter activity by AML1-related transcription factor, PEBP2

The granulocyte-macrophage colony-stimulating factor (GM-CSF) gene promoter contains a consensus sequence for the polyomavirus enhancer binding-protein 2 (PEBP2) transcription factor, which consists of alpha and beta subunits. There are at least two genes, alpha A and alpha B, encoding the alpha subunit. alpha B is the mouse homologue of human AML1 gene detected at the breakpoints of t(8;21) and t(3;21) myeloid leukemias. We examined alpha A1 (an alpha A-gene product) and alpha B1 and alpha B2 (two alpha B-encoded isomers) for their effects on the GM-CSF promoter. PEBP2 alpha A1, alpha B1, and alpha B2 proteins bound the PEBP2 site within the mouse GM-CSF promoter. PEBP2 alpha A1 and alpha B1 enhanced the expression of the GM-CSF promoter-driven reporter plasmid in unstimulated and 12-O-tetradecanoylphorbol 13-acetate/phytohemagglutinin-stimulated human Jurkat T cells. In contrast, the promoter activity was suppressed by alpha B2. Coexpression of alpha B1 and alpha B2 showed that the promoter activity could be determined by the alpha B1/alpha B2 ratio. Jurkat cell extract contained PEBP2 site-binding protein(s) that cross-reacted with antimouse alpha A1 antibodies. Northern blot analysis indicated the expression of human PEBP2 alpha A, alpha B (AML1), and beta genes in Jurkat cells. Although further studies are required to determine the precise role of PEBP2 in the GM-CSF promoter activity, the present findings suggested the importance of the relative ratio of different PEBP2 isoforms in regulating the levels of the promoter activity.

Isolation and characterization of [Pro2]somatostatin-14 and melanotropins from Russian sturgeon, Acipenser gueldenstaedti Brandt

A new form of somatostatin (SRIH), along with melanotropins (MSHs), was isolated from pituitaries of the Russian sturgeon Acipenser gueldenstaedti Brandt by gel filtration, ion exchange, and reversed-phase HPLC following acid-acetone extraction. The sturgeon SRIH consists of 14 amino acid residues and differs from mammalian SRIH-14 by the substitution Pro for Gly at position 2. Synthetic [Pro2]SRIH-14 was as potent as mammalian SRIH-14 in inhibiting release of growth hormone into medium from the organ-cultured pituitary of rainbow trout. Sturgeon alpha-MSH has the same amino acid sequence as those found in mammals. Sturgeon beta-MSH is composed of 17 amino acid residues, and its amino acid sequence is identical to the N-terminal 15 residues of salmon beta-MSH I and to the C-terminal 2 residues of mammalian beta-MSH.

[Restenosis after percutaneous transluminal coronary angioplasty in the elderly--risk factor analysis]

Utilization of percutaneous transluminal coronary angioplasty (PTCA) has dramatically expanded even in the management of elderly patients with coronary artery disease. However, restenosis after successful PTCA remains the major problem limiting the long-term efficacy of the procedure. Reported restenosis rates vary from 25 to 43%. In order to determine the relationship of restenosis to coronary risk factors in the elderly, we analyzed the data in 87 patients who had undergone PTCA and angiography before and 3 to 6 months after PTCA. Of these, 29 patients were 65 years of age or older (elderly group) and 58 were less than 65 years of age (younger group). Restenosis, defined as a luminal narrowing of greater than 50% at follow-up time, was found in 20 of the elderly group (69.0%), and in 26 (44.8%) of younger group (p < 0.0001). Total cholesterol, LDL cholesterol, apolipoprotein B (apo B), and the ratio of apoB/apoA1 in the elderly group were significantly lower than those in the younger group. HDL cholesterol levels were lower than 40 mg/dl in both groups (not significant). Each group was subdivided into two types; restenosis type and non-restenosis type. There were no significant differences in serum lipid, apolipoprotein, and lipoprotein(a) levels between the 2 subtypes in each group. The degree of coronary atherosclerosis calculated by Gensini's method, the number of damaged coronary vessels, diabetes mellitus, hypertension, and smoking did not appear to affect the rate of restenosis in either group.(ABSTRACT TRUNCATED AT 250 WORDS)

Elevated cerebrospinal fluid levels of manganese superoxide dismutase in bacterial meningitis

We examined the mechanism of increase of manganese superoxide dismutase (Mn SOD) in the cerebrospinal fluid (CSF) in bacterial meningitis (BM). The elevated levels of Mn SOD in the CSF in BM, measured with an enzyme immunoassay method, were more prominent than those in aseptic meningitis (AM) and encephalitis (EN). In AM and EN Mn SOD levels well correlated with levels of neuron-specific enolase and S-100b protein, which are markers of damages to nervous tissues, but did not with any of them in BM. CSF concentrations of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 alpha (IL-1 alpha) were higher in BM than in AM and EN. From the serial measurements in BM, the peak values of these cytokines chronologically preceded or corresponded to those of Mn SOD. Immunohistochemically, a large number of the glial cells were stained for Mn SOD in the cerebral cortex from a patient with BM. By contrast, in the normal cerebral cortex, the glial cells were negative for Mn SOD staining. These results suggest that the marked increase of Mn SOD in the CSF in BM may be related to the increase of such cytokines as TNF-alpha and IL-1 alpha and that these cytokines may play a role in the induction of Mn SOD in nervous tissues.

Undifferentiated carcinoma in the cardioesophageal junction which produces parathyroid hormone related protein

A 68-year-old man with undifferentiated carcinoma occurring in the cardioesophageal junction accompanied by hypercalcemia is reported. The serum level of parathyroid hormone-related protein (PTHrP) was remarkably elevated. Serum calcium and PTHrP levels decreased following chemotherapy, but this amelioration was temporary. He died of hypercalcemia. On autopsy, a significant amount of immunoreactive PTHrP was detected in the tumor tissue extract, and the tumor cells were stained strongly positive for PTHrP by immunohistochemistry. This is the first case of undifferentiated carcinoma in the gastrointestinal tract which demonstrated hypercalcemia due to PTHrP produced by the malignant tumor.

A scintigraphical qualitative analysis of peripheral vascular sympathetic function with meta-[123I]iodobenzylguanidine in neurological patients with autonomic failure

In order to assess qualitatively the sympathetic functions of the peripheral vessels, we performed a scintigraphical study of the entire body with meta-[123I]iodobenzylguanidine (MIBG) in 13 patients with autonomic failure and 11 healthy subjects as control. The patients comprised seven with multiple system atrophy (MSA), two with pure autonomic failure (PAF), three with Parkinson's disease with autonomic failure (PD with AF) and one with familial amyloid polyneuropathy (FAP). No clinical evidence of vascular disease was noted in any of the patients and the control subjects. We investigated their autonomic functions using the head up tilt test as well as norepinephrine and isoproterenol infusion tests. We found that: (i) All of the control subjects showed satisfactory MIBG uptake; (ii) all of the patients with PAF and FAP, most of whom had postganglionic sympathetic lesions, showed supersensitivity and low MIBG uptake; (iii) almost all the patients with MSA, who were considered to have mainly preganglionic sympathetic lesions, showed supersensitivity and diminished MIBG uptake, although the patients with olivopontocerebellar atrophy showed supersensitivity but not diminished MIBG uptake. In conclusion, these results suggest that peripheral vascular scintigraphy using MIBG is useful in detecting peripheral adrenergic dysfunction.

Synergistic effects of insulin-like growth factor II (IGF-II) with leukemia inhibiting factor (LIF) on establishment of rat pluripotential cell lines

To examine effects of IGF-II on establishment of pluripotential diploid cells from rat embryos, we cultured blastocysts in medium containing mouse LIF with or without IGF-II. Combination of mouse LIF (5,000 units/ml) and rat IGF-II (100 ng/ml) promoted growth of inner cell mass (ICM) and was effective for establishment of pluripotential cell lines derived from the ICM. The cell lines indicated colony forms different from the rat ES cell lines. However, they showed morphological alteration to adult-like tissue cells, formed embryoid body in suspension culture, and thus, seemed to retain a pluripotent characteristics. The rat IGF-II is useful for establishing of pluripotential cells efficiently.

Prolonged inhibition of an antigen-specific IgE response in vivo by monoclonal antibody against lymphocyte function-associated antigen-1

Intraperitoneal injection of ovalbumin (OVA) into BALB/c mice caused the induction of OVA-specific IgE production in vivo. However, administration of monoclonal antibody against lymphocyte function-associated antigen-1 (anti-LFA-1 mAb) at days 0 and 1 after OVA immunization resulted in an inhibition of OVA-specific primary and secondary IgE production in a dose-dependent manner. The inhibition of the antigen-specific IgE response due to anti-LFA-1 mAb was seen up to 8 weeks after anti-LFA-1 mAb administration. The OVA-specific IgG1 response was also blocked by anti-LFA-1 mAb. The spleen cells obtained from OVA-immunized mice showed enhanced proliferation against secondary stimulation with OVA in vitro. However, the spleen cells obtained from the mice treated with both OVA and anti-LFA-1 mAb revealed a markedly decreased proliferative responses to OVA, while they showed no reduced responses against keyhole limpet hemocyanin stimulation, indicating that anti-LFA-1 mAb might induce antigen-specific anergy in vivo. It was also demonstrated that treatment of the mice with anti-LFA-1 mAb significantly inhibited the interleukin-4-producing ability of OVA-immunized mouse spleen cells. These results demonstrated that LFA-1-dependent cell-cell interaction is essential for the production of IgE in vivo and may be important in IgE-dependent allergic disease.

Gastrointestinal manometry findings in a case with dilated small bowel and disturbed transit treated successfully with bowel plication

We report the manometric findings in a case of dilated small bowel and disturbed transit successfully treated with plication of the dilated small bowel. The female newborn infant required total parenteral nutrition following an operation for small bowel atresia. X-ray showed a dilated proximal small bowel. Jejunal manometry showed normal phase 3 migration but persistently low-amplitude contractions in the dilated segment. After plication of the dilated intestine, symptoms of bowel obstruction disappeared. A second manometry two weeks after the operation showed contractions with normal amplitude. These findings indicate that: (1) disturbed transit in the dilated intestine proximal to small intestinal atresia is associated with persistently low contraction amplitude, and (2) the amplitude can be increased by the plication of the dilated loop.

Bcl-2 oncoprotein expression and apoptosis in neuroblastoma

Bcl-2 protooncogene, originally discovered at the chromosomal breakpoint of the t(14;18) in follicular lymphoma, is known to regulate the process of programmed cell death or apoptosis. The inhibition of apoptosis is thought to be one of the mechanisms involved in the development of tumors. To investigate the possible association of bcl-2 protooncogene with the tumorigenesis of neuroblastomas, the authors examined bcl-2 expression by immunohistochemistry in 49 neuroblastomas and 7 ganglioneuromas. The distribution of apoptotic cells was also examined by the TUNEL method (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling). Bcl-2 oncoprotein was detected in the cytoplasm in 40 of 49 neuroblastomas (81.6%). There was no correlation between bcl-2 oncoprotein expression and the clinical features of neuroblastoma. The incidence of bcl-2-positive tumors in ganglioneuroma was significantly lower than that in neuroblastoma (28.6%) (P < .01). TUNEL stained the nuclei of tumor cells in 11 of 34 (32.4%) neuroblastomas. TUNEL-positive cells tended to be located around calcifications in neuroblastomas in patients less than 1 year old. Examination of serial sections showed that apoptotic cells were distributed in the area where bcl-2 oncoprotein was not expressed. What we have observed indicates that apoptosis of neuroblastoma cells may be regulated by bcl-2 expression. Our observations suggest that the survival of neuroblastoma cells might be promoted by bcl-2 expression and that bcl-2 might be associated with the tumorigenesis of neuroblastomas.

3,4-dihydroxyphenylalanine (DOPA) decarboxylase deficiency and resultant high levels of plasma DOPA and dopamine in unfavorable neuroblastoma

Neuroblastoma (NB) is a tumor which arises from neural crest cells. In the developing neural crest cells, the induction of 3,4-dihydroxyphenylalanine (DOPA) decarboxylase is more delayed than that of tyrosine hydroxylase and dopamine-beta-hydroxylase. If NB cells are arrested in an early stage of neural crest development, the induction of DOPA decarboxylase is insufficient and the accumulation and secretion of DOPA can be caused. The biochemically immature phenotype is thought to represent the undifferentiated characteristics of the cells and might correlate with the grade of malignancy. To investigate whether the hypothesis is clinically applicable or not, we have measured plasma DOPA, dopamine and urinary catecholamine metabolites in NB patients. The levels of plasma DOPA, dopamine, urinary homovanillic acid (HVA) and vanillactic acid (VLA) were significantly higher in patients with unfavorable NBs and the higher plasma DOPA level was significantly associated with the patients' age (> 1 year old), tumor stage (III, IV) and DNA diploidy. Serial determination of plasma DOPA was a good monitor of the disease course. These results are compatible with the hypothesis on DOPA decarboxylase deficiency and DOPA secretion in undifferentiated, unfavorable NBs. In conclusion, the plasma DOPA can be used to predict patients' prognosis as well as to follow up patients with NB.

Cerebrospinal fluid levels of S-100b protein and neuron-specific enolase in chronic inflammatory demyelinating polyneuropathy

We measured the cerebrospinal fluid (CSF) concentrations of S-100b protein (S-100b) and neuron-specific enolase (NSE) using enzyme immunoassay methods in 15 patients with chronic inflammatory demyelinating polyneuropathy (CIDP), other three patients with chronic neuropathy with demyelination, eight patients with various axonal neuropathies (AN), and 46 controls, to investigate the clinical usefulness of the determination of these two specific proteins in these neuropathies. S-100b levels were elevated (> the mean +/- 2 SD levels of controls) in the majority of patients with clinically progressing CIDP (9/11), but not in the patients with AN (0/8). In parallel with the clinical improvement, S-100b levels were normalized in patients with CIDP (10/10), though total protein levels in the CSF still remained high in some of these patients (5/10). Elevation of NSE levels were seldom seen in clinically worsening patients with CIDP (1/11) or AN (1/8). Thus our results indicated that the level of S-100b in the CSF may be useful to assess the activity of actual disease process in CIDP.

[Clinical efficacy of neoadjuvant M-VAC chemotherapy for invasive bladder cancer]

We clinically evaluated the efficacy of neoadjuvant M-VAC (methotrexate, vinblastine, doxorubicin and cisplatin) therapy followed by radical cystectomy. A total of 21 patients with locally invasive bladder cancer received neoadjuvant M-VAC therapy with an average of 2.4 courses (range 2-4). Of the 21 patients, 4 had stage T2N0M0, 11 had stage T3aN0M0, 5 had stage T3bN0M0 and 1 had stage T4N0M0 at diagnosis. Of the 21 patients, 3 had clinically complete responses (cCR) and 12 had partial responses (cPR), for an overall response rate of 71.4%. The patients who responded to the chemotherapy (cCR + cPR) had a 2-year disease free rate of 80.0% in contrast to 50.0% for the remaining patients who did not respond. A pathological response (pT0, pT1) was achieved in 6 (28.6%) of the 21 patients. The 5 patients in this group remain free of disease for 15 to 79 months (mean 58.8 months). These preliminary results suggest that the patients who achieve either a complete or partial response, in particular those had pathological stage of pT0 or pT1, may have a favorable clinical course.

Retrospective analysis of biological factors in a recurrent IV-S neuroblastoma with intermediate-grade malignancy

A clinical stage of IV-S neuroblastoma is known to include heterogeneous tumors. The authors report a case of IV-S neuroblastoma that relapsed after regression 4 years and 10 months after diagnosis. Multiagent chemotherapy was necessary to control the disease, and the patient has been doing well with no evidence of disease for more than 5 years. Although Shimada's classification showed favorable characteristics, N-myc protein was positive and DNA ploidy was diploidy in the tumor at diagnosis. Discrepancy in DNA ploidy was observed and aneuploidy was shown in tumor specimens at recurrence. Experience in this case showed the following important clinical features: (1) IV-S neuroblastoma of intermediate-grade malignancy does exist, and patients with such a disease may be cured by aggressive treatment; (2) Identifying IV-S patients with an unfavorable clinical course is possible by examining biological prognostic factors.

Okadaic acid induces both augmentation and inhibition of opsonized zymosan-stimulated superoxide production by differentiated HL-60 cells. Possible involvement of dephosphorylation of a cytosolic 21K protein in respiratory burst

We found that okadaic acid (OA), a potent tumor promoter and a phosphatase inhibitor, has a unique opposing effect on opsonized zymosan (Op.-zym.)-elicited O2.- production by differentiated HL-60 cells in a narrow range of concentrations but does not induce any O2.- production by itself. Okadaic acid magnified the O2.- production 2.5-fold at 1.0 microM, while it inhibited it at 2.0 microM or higher concentrations. This effect of OA did not correspond to the changes in the expression of surface receptors (CD11b/CD18, CR3) for Op.-zym., because they were weakly down-regulated by OA at any concentration. Two-dimensional gel electrophoresis revealed that in the absence of OA, Op.-zym. induced rapid dephosphorylation of a cytosolic 21K protein with a very slight increase in phosphorylation of membranous p47phox, which is one of the cytosolic factors required for respiratory burst. In the presence of a stimulatory concentration (1.0 microM) of OA, the Op.-zym.-caused dephosphorylation of the 21K protein was still observed and the phosphorylation of p47phox was enhanced. In the presence of an inhibitory concentration (2.0 or 5.0 microM) of OA, the Op.-zym.-induced dephosphorylation of the 21K protein was strongly inhibited while p47phox was heavily phosphorylated. Acid hydrolysis of the 21K phosphoprotein yielded only phosphoserine as a phosphoamino acid. Furthermore, at least part of the 21K protein seemed to be associated with p67phox and p47phox, because it was co-immunoprecipitated with those cytosolic factors. These results suggest that a cytosolic 21K protein plays an important role in respiratory burst through dephosphorylation by a phosphoserine phosphatase, and that the dephosphorylated 21K protein may work synergistically with the phosphorylated p47phox on the pathway for activation of the respiratory burst oxidase.

Establishment of a T cell-dependent nude mouse liver injury model induced by Propionibacterium acnes and LPS

Normal ICR mice developed severe liver injury when they were given intravenous injections of Propionibacterium acnes and lipopolysaccharide (LPS) with a 7 day interval. In contrast, T cell-deficient ICR nude mice were resistant to P. acnes and LPS-induced liver injury. However, athymic ICR nude mice, which were treated with cell transfer of normal ICR mouse spleen cells (10(8) cells) or ICR mouse nylon-wool passed splenic T-enriched cells (over 10(7) cells), showed severe liver injury as assessed by elevation of serum transaminase activities. Histological analyses also demonstrated that the transferred cells migrated into the liver of nude mice to induce liver injury. However, depletion of both CD4+ T cells and CD8+ T cells from transferred cell populations caused a marked decrease in the elevation of serum transaminase, indicating the actual involvement of T cells in liver injury. Moreover, in vivo administration of anti-LFA-1 mAb blocked P. acnes and LPS-induced liver injury in nude mice following T cell transfer. Thus, this model will provide a new strategy to investigate T cell-dependent cell-cell interaction during the induction of liver damage.