The restrictive proteolysis of alpha-fodrin to a 120 kDa fragment is not catalyzed by calpains during thymic apoptosis

The alpha-subunit (240 kDa) of fodrin was found to be digested selectively to a 120 kDa fragment during apoptosis of rat thymocytes in vivo and in vitro. This fragment was detected by an antibody (Ab) against full length alpha-fodrin, but not by the anti-N-terminal sequence (GMMPR) of the mu-calpain-generated 150 kDa fragment Ab or the anti-PEST sequence of alpha-fodrin Ab. On the other hand, basal levels of the 150 kDa fragment were constantly recognized by these three antibodies during apoptosis. The production of the 120 kDa fragment during apoptosis was not affected by the addition of calpain inhibitors such as Ac-LLLnal and E-64d, despite inhibition of the generation of the 150 kDa fragment. When x-irradiated thymocytes were incubated in the presence of N-tosyl-L-phenylalanyl chloromethyl ketone (TPCK), both production of the 120 kDa fragment and apoptosis were suppressed. Purified mu- and m-calpain did not catalyze the formation of the 120 kDa fragment from purified alpha-fodrin in vitro. These results suggest that a protease different from calpains is involved in the major process of alpha-fodrin proteolysis to a 120 kDa fragment during thymic apoptosis.

Pulsed liquid jet dissector using holmium:YAG laser--a novel neurosurgical device for brain incision without impairing vessels

BACKGROUND

Neurosurgery has long required a method for dissecting brain tissue without damaging principal vessels and adjacent tissue, so as to prevent neurological complications after operation. In this study we constructed a prototype of such a device and used it in an attempt to resect beagle brain cortex.

METHOD

The prototype device consisted of an optical fibre, a Y adaptor, and a nozzle whose internal exit diameter was 100 microm. Cold physiological saline (4 degrees C) was supplied to it at a rate of 40 ml/h. Pulsed liquid jets were ejected from the nozzle by a pulsed Holmium:YAG) (Ho:YAG) laser at an irradiation energy of 300 mJ/pulse. The profile of the liquid jet was observed with a high-speed camera while changing the distance between the optical fibre end and nozzle exit (equivalent to the standoff distance). With this device (3 Hz operation), brain dissection of anaesthetized beagles was attempted while measuring the local temperature of the target. A histological study of the incised parts was also performed.

FINDINGS

When the standoff distance was 24 mm, the liquid jet was emitted straight from the nozzle at a maximum initial velocity of 50 m/s. The brain parenchyma was cut with this device while preserving vessels larger than 200 microm in diameter and keeping the operative field clear. The local temperature rose to no more than 41 degrees C, below the functional heat damage threshold of brain tissue. Histological findings showed no signs of thermal tissue damage around the dissected margin.

INTERPRETATION

The Ho:YAG laser-induced liquid jet dissector can be applied to neurosurgery after incorporating some minor improvements.

Holmium:YAG laser-induced liquid jet dissector: a novel prototype device for dissecting organs without impairing vessels

BACKGROUND AND OBJECTIVE

Neurosurgery has long required a method for dissecting brain tissue without damaging principal vessels and adjacent tissue, so as to prevent neurological complications after operation. In this study we fabricated such a prototype device and used it in an attempt to resect an animal liver, which, like the brain, contains many vessels.

MATERIALS AND METHODS

The prototype device consisted of a jet nozzle and a suction tube. Pulsed liquid jets at 3 Hz were ejected from the nozzle by a pulsed holmium:YAG (Ho:YAG) laser at an irradiation energy of 230 mJ/pulse. The profile of the liquid jet was observed with a high-speed camera. With this device, liver dissections of anesthetized rabbits were attempted while measuring the local temperature of the target. A histological study of the incised parts was also performed.

RESULTS

The liquid jet was emitted straight from the nozzle at an initial velocity of 38 m/sec. The liver parenchyma was cut with the device while preserving the tiny vessels and keeping the operative field clear. The local temperature rose to no more than 314 K (below the heat damage threshold of brain tissue). In the histological findings, there were no signs of hepatic degeneration or necrosis around the dissected margin.

CONCLUSIONS

The Ho:YAG laser-induced liquid jet dissector can be applied to neurosurgical operations after incorporating some minor improvements.

Genomic dissection for characterization of cancerous oral epithelium tissues using transcription profiling

Genome-wide and high-throughput functional genomic tools offer the potential of identifying disease-associated genes and dissecting disease regulatory patterns. There is a need for a set of systematic bioinformatic tools that handles efficiently a large number of variables for extracting biological meaning from experimental outputs. We present well-characterized statistical tools to discover genes that are differentially expressed between malignant oral epithelial and normal tissues in microarray experiments and to construct a robust classifier using the identified discriminatory genes. Those tools include Wilks' lambda score, error rate estimated from leave-one out cross-validation (LOOCV) and Fisher Discriminant Analysis (FDA). High Density DNA microarrays and Real Time Quantitative PCR were employed for the generation and validation of the transcription profile of the oral cancer and normal samples. We identified 45 genes that are strongly correlated with malignancy. Of the 45 genes identified, six have been previously implicated in the disease, and two are uncharacterized clones.

Combinatorial peptide library for the analysis of antigen recognition by T cells

Peptides that consist of 19 residues with random sequences (X19) were considered to deliver antigenic stimuli to CD4T cells. When IL-4, IL-7, IL-9, IL-15 and agonistic Ab to CD29 were co-cultured with single peripheral CD4T cells in the presence of X19 and feeder cells, T cells exhibited clonal expansion. These T cell clones showed heterogeneous proliferation patterns against KGXXXXXXXXXGK-based and KGXXXXXXXXXGKGKK-based combinatorial peptide libraries. Pattern-match search on one of the T cell clones resulted in peptide ligand candidates, one of which induced proliferation, as did protein molecules carrying the corresponding sequence. Combinatorial chemistry was useful in determining not only peptide ligands but also peptide superagonists. For this purpose, use of reverse-phase hydrophobic interaction chromatography and mass spectrometry analysis was efficient. Detailed methods are described in the paper.

Progress with inactivated poliovirus vaccines derived from the Sabin strains

To produce a safe and effective inactivated poliovirus vaccine (IPV), we have developed S-IPV using Vero cells infected with the Sabin strains in a semi-production scale. All production steps including virus culture on microcarrier beads were highly reproducible. Mean recovery percents of infectious viruses or D-antigens during all processes for concentration, purification and inactivation were 30-50% in the three types. The S-IPV potency was adjusted for D-antigen content as determined by in-house ELISA and was comparable to WHO reference IPV derived from the virulent strains in immunogenicity tests in rats. Antibody development in more than 30 seronegative infant volunteers after two shots of S-IPV at four-week interval were 100% without notable adverse reactions. The mean antibody titres (log2) to Sabin 1, 2 and 3 viruses were 11.1, 8.3 and 8.9, respectively. The antibodies neutralized the Mahoney, MEF-1, and Saukett virulent strains with slightly inferior titres to those of the Sabin strains. D-antigens for each type of S-IPV were stable at 4 degrees C without any significant decrease over more than two years.

Odontogenic carcinoma: a functional genomic comparison with oral mucosal squamous cell carcinoma

Intraosseous squamous cell carcinomas of the mandible arise de novo or secondary to a tumor or transformed cyst epithelium. Current diagnostic tests frequently fail to distinguish between these tumors, leading to confusing classification schemes. We report the functional genomic analysis of a mandibular odontogenic carcinoma. Malignant keratinocytes from the lesion were isolated using laser capture microdissection. Target sample generated from the total RNA of the LCM-procured cells was used to hybridize high-density oligonucleotide arrays. Functional genomic analysis of the odontogenic carcinoma database compared with four oral mucosal squamous cell carcinoma gene expression databases was performed. Preliminary results suggest a small subset of genes distinguish this odontogenic carcinoma from oral mucosal epidermoid carcinomas.

Plaque rupture on the carotid artery observed by Doppler ultrasonography--a case report

Plaque rupture may play an important role in acute cerebral events. Recent technological advances in ultrasonographic systems provide a feasible diagnostic modality of atherosclerotic lesion by clearly visualizing flow conditions and vessel morphology. A 58-year-old man with chronic renal failure underwent duplex Doppler ultrasound in which ruptured plaque on carotid arterial wall was imaged. Color Doppler imaging showed that the plaque shoulder at the proximal site was hit by forward flow to the brain and ruptured. Curling flow in the inner space of the plaque was observed. Carotid arteriography at the corresponding site of ruptured plaque revealed the space within the plaque similarly contrasted. A magnetic resonance imaging of brain performed after identifying plaque rupture revealed small cerebral infarcts at the cerebral cortex. Plaque rupture could be demonstrated by color Doppler imaging at the proximal edge of plaque and curling flow in the intraplaque space may have released small thrombi to vessel lumen. Plaque rupture of the carotid artery may play an important role in the development of small cerebral infarction.

T cell responses to major membrane protein II (MMP II) of Mycobacterium leprae are restricted by HLA-DR molecules in patients with leprosy

Major membrane protein II (MMP II) of Mycobacterium leprae (M. leprae) is a 22kDa protein inducing humoral immune response in leprosy patients. MMP II-specific bulk T cell lines were established from leprosy patients to determine major T cell epitopes in MMP II and to evaluate lymphokine production induced by MMP II. These bulk T cell lines reacted to one or more peptides in the locus of amino acid residues from 23 to 109 of MMP II. The proliferative responses of all T cell lines were mainly inhibited by the addition of anti-DRB1 mAb. Many bulk T cell lines induced IFN-gamma, IL-5, but not IL-4. However, it was not possible to distinguish the LL or TT types of leprosy based on the pattern of T cell epitopes and the lymphokine productivity in the responses against MMP II. Thus, it appears that T cell response to MMP II is restricted by the HLA-DRB1 molecule, but not by DQ and DP molecules, which results in the induction of IFN-gamma production.

Association of plasma adrenomedullin with carotid atherosclerosis in chronic ischemic stroke

Adrenomedullin is a potent vasodilator peptide exerting anti-atherosclerotic actions in vitro. We investigated the impact of the severity of atherosclerosis on plasma mature-adrenomedullin (m-AM) levels in 38 patients with chronic ischemic stroke. The variables of carotid artery atherosclerosis assessed using ultrasound measurement, blood pressure, and risk factors were related to m-AM levels. Severe atherosclerosis was associated with a further elevation of the increased m-AM level in patients with high systolic blood pressure. Even in patients with fewer risk factors, the presence of severe atherosclerosis was associated with an increased m-AM level. Thus, atherosclerosis elevates m-AM independent of the blood pressure level or presence of risk factors.

Oral cancer in vivo gene expression profiling assisted by laser capture microdissection and microarray analysis

Large scale gene expression profiling was carried out on laser capture microdissected (LCM) tumor and normal oral epithelial cells and analysed on high-density oligonucleotide microarrays. About 600 genes were found to be oral cancer associated. These oral cancer associated genes include oncogenes, tumor suppressors, transcription factors, xenobiotic enzymes, metastatic proteins, differentiation markers, and genes that have not been implicated in oral cancer. The database created provides a verifiable global profile of gene expression during oral carcinogenesis, revealing the potential role of known genes as well as genes that have not been previously implicated in oral cancer.

Hepatitis C virus (HCV) infection as a risk factor for spontaneous intracerebral hemorrhage: hospital based case-control study

Hepatitis C Virus (HCV) infection was investigated as a risk factor for intracerebral hemorrhage (ICH) by HCV antibody screening in 462 patients with ICH and 462 control patients with cerebral infarction matched by age and sex. Laboratory examinations of hemostatic parameters and cholesterol level were also performed in patients with ICH. HCV infection was significantly more frequent in patients with ICH than controls (8.7% vs 3.5%, P< 0.01). ICH patients with HCV infection had significantly higher L-alanine:2-oxoglutarate aminotransferase level (P< 0.001), lower cholesterol level (P< 0.05), lower platelet count (P< 0.05), and longer prothrombin time (P< 0.01) than ICH patients without HCV infection, although most of these values were within the normal range. These results demonstrate that HCV infection is a risk factor for spontaneous ICH. Subclinical clotting disorder and/or vessel wall friability resulting from hypocholesteremia may be associated with ICH in patients with HCV infection.

Reduction of p12DOC-1 expression is a negative prognostic indicator in patients with surgically resected oral squamous cell carcinoma

PURPOSE

p12DOC-1 is a growth suppressor that negatively regulates cyclin-dependent kinase 2 (CDK2) activities. Expression of p12DOC-1 is reduced and/or lost in tumor tissues. The purpose of this study is to correlate in vivo the expression of p12DOC-1 in oral cancer tissues by immunohistochemistry with clinical and pathological parameters.

EXPERIMENTAL DESIGN

Twenty-five cases of normal oral mucosa and 127 cases of oral squamous cell carcinomas were evaluated. Patients' charts were reviewed for clinical, pathological, and 10-year survival data. Because p12DOC-1 is a growth suppressor and associates with CDK2, parallel immunostaining was done for proliferating cell nuclear antigen and CDK2 to evaluate cell proliferation and potential correlation with CDK2.

RESULTS

Our results showed that strong p12DOC-1 staining was uniformly seen in normal oral mucosa. p12DOC-1 staining was reduced or absent in 81 cases (63.8%) of oral squamous cell carcinomas. Decreased p12DOC-1 staining (<25% of cells stained) correlated with tumor mode of invasion (P = 0.001) and higher proliferating cell nuclear antigen (P = 0.0028) and CDK2 (P = 0.0020) expression. Survival analysis showed significant correlation of low p12DOC-1 expression with the risk of cervical lymph node metastasis (P = 0.001) and patients' 10-year survival status (P = 0.0214).

CONCLUSIONS

These results allow us to conclude that reduction of p12DOC-1 protein expression is a frequent event in oral cancers. Intratumor immunohistochemical evaluation of p12DOC-1 expression can be an adjunctive prognostic indicator for patients with oral cancer.

Phosphatidylserine induces apoptosis in CHO cells without mitochondrial dysfunction in a manner dependent on caspases other than caspases-1, -3, -8 and -9

Treatment of Chinese hamster ovary K1 cells with phosphatidylserine (PS) caused typical apoptosis with distinct morphological and biochemical features in a dose- and time-dependent manner. However, unlike camptothecin-induced apoptosis, changes in mitochondrial transmembrane potential were not observed. In addition, cytochrome c release did not occur in PS-induced apoptosis. A pan caspase inhibitor, Z-VAD, significantly inhibited the apoptosis, but inhibitors of caspase-1, -3, -8 and -9 did not. Activities of caspase-1, -3, -8 and -9 were increased by treatment of the cells with camptothecin, but not with PS. These results suggest that PS-induced apoptosis occurs without the collapse of mitochondrial transmembrane potential and without the release of cytochrome c, in a manner independent of caspase-1, -3, -8 and -9.

Rescue of lethally irradiated mice from hematopoietic death by pre-exposure to 0.5 Gy X rays without recovery from peripheral blood cell depletion and its modification by OK432

Exposing mice to 0.5 Gy X rays 2 weeks before lethal irradiation has been reported to induce marked radioresistance and to rescue them from hematopoietic death. Here we examined effects of the 0.5-Gy pre-exposure on hematological changes in C57BL mice that were lethally irradiated with 6.5 Gy X rays. Approximately 77% of pre-exposed mice survived 30 days after this irradiation, whereas 80% of mice that did not receive this pre-exposure died by day 20. However, regardless of the pre-exposure, peripheral blood cell counts decreased markedly by day 3 and reached a nadir at day 20. CFU-S in femur and CFU-GM in spleen had started to recover at day 10 and 14, respectively, but recovery of functional peripheral blood cells occurred later. The effect of pre-exposure on survival was altered by OK432, a bioresponse modifier; the effect depended on the timing of its administration. OK432 given 2 days before 0.5 Gy enhanced the protective effect of pre-exposure, resulting in the survival of 97% of the mice. In contrast, injection of OK432 1 day before or 2 days after pre-exposure led to 100% mortality. Thus the survival-promoting effect of 0.5 Gy could be altered by OK432. The OK432-induced changes in the survival of mice could not be attributed solely to hematological changes, as shown by blood cell counts and progenitor cell contents. These results suggest that radioresistance induced by pre-exposure to 0.5 Gy X rays is not stable, but rather varies with the physiological conditions, and can be modulated by factors such as OK432.

Angiotensin-converting enzyme inhibition with enalapril slows progressive intima-media thickening of the common carotid artery in patients with non-insulin-dependent diabetes mellitus

BACKGROUND AND PURPOSE

Whether angiotensin-converting enzyme (ACE) inhibitors have any clinically significant antiatherogenic effects in humans remains unproven. We undertook a prospective randomized clinical trial of 98 patients with non-insulin-dependent diabetes mellitus (NIDDM) to examine the efficacy of ACE inhibition with enalapril for preventing intima-media (IM) thickening of the carotid wall as measured ultrasonographically.

METHODS

Ninety-eight NIDDM patients were randomly assigned either to enalapril at 10 mg/d (n=48) or to a control group (n=50); the planned duration of the trial was 2 years. All patients were seen at baseline (study entry) and 2 subsequent formal annual evaluations, in addition to standard clinical management for NIDDM. IM thickening and vascular lumen diameters were determined for all patients on the basis of baseline and 2 subsequent annual evaluations with carotid ultrasonography. We performed an intent-to-treat analysis to assess changes in IM thickening over the course of the study.

RESULTS

Annual IM thickening measurements of the right and left common carotid arteries were 0.01+/-0.02 and 0.01+/-0.02 mm/y in the enalapril-treated group and 0.02+/-0.03 and 0.02+/-0.02 mm/y in the control group, respectively (P<0.05). From regression analysis, annual IM thickening was found to be predicted by enalapril use, sex, and insulin use (F(3,94)=3.86, P=0.012). When we controlled for these other variables, enalapril use reduced annual IM thickening of right and left common carotid arteries by 0.01+/-0.004 mm/y relative to the control group over the course of this study.

CONCLUSIONS

Long-term treatment with an ACE inhibitor (enalapril) slows progressive IM thickening of the common carotid artery in NIDDM patients.

Inhibition of cardiac delayed rectifier K+ currents by an antisense oligodeoxynucleotide against IsK (minK) and over-expression of IsK mutant D77N in neonatal mouse hearts

The IsK (minK or KCNE1) protein is known to co-assemble with the KvLQT1 (KCNQ1) protein to form a channel underlying the slowly activating delayed rectifier K+ current (IKs). Controversy remains as to whether the IsK protein assembles with ERG (the ether-a-go-go-related gene) products to form or modulate the channel-underlying the rapidly activating delayed rectifier K+ current (IKr). We investigated the effects of antisense oligodeoxynucleotides (AS-ODN) against IsK and its mutant D77N [which underlies a form of long QT syndrome (LQT5) in humans] on the delayed rectifier K+ current (IK) of neonatal mouse ventricular myocytes in primary culture. Patch-clamp experiments on these cells showed that IK consists of IKs and IKr. IK was not recorded from ventricular cells transfected with AS-ODN, while it was recorded from cells transfected with the corresponding sense oligodeoxynucleotides (S-ODN). IK was not recorded from cells transfected with the D77N mutant, and the action potential duration was much longer than in cells transfected with wild-type IsK. Furthermore, HERG could not induce currents in COS-1 cells co-expressed with the D77N mutant and HERG (the human form of ERG). These results indicate that the IsK protein associates with both KvLQT1 and ERG products to modulate IKr and IKs in cardiac myocytes.

Thrombin inhibition attenuates neurodegeneration and cerebral edema formation following transient forebrain ischemia

The disturbance of microcirculation following cerebral ischemia leads to an enlargement of cerebral infarct volume. Endogenous thrombin may play a role in this disturbance of microcirculation following cerebral ischemia. Therefore, the inhibition of thrombin may improve neurodegeneration and the accumulation of cerebral edema following cerebral ischemia in gerbils. The effects of thrombin inhibitor (argatroban) on cerebral ischemia were investigated in comparison with thromboxane A2 synthase inhibitor (ozagrel) and cyclooxygenase inhibitor (aspirin) following bilateral common carotid artery occlusion and reperfusion (CCA:O/R) in male Mongolian gerbils. This study consisted of three experiments: (1) morbidity and survival ratio (n=40 for each), (2) histopathology (n=12 for each), and (3) mean arterial blood pressure, local cerebral blood flow (CBF), and cerebral specific gravity (n=8 for each). Argatroban treatment improved survival ratio and stroke index, and decreased ischemically injured cell numbers in cortex and hippocampus and cerebral edema in cortex compared with aspirin and saline, in concert with the fast recovery of local CBF without reactive hyperemia following bilateral CCA:O/R. Ozagrel treatment also improved those factors compared with saline, in concert with the fast recovery of local CBF with reactive hyperemia. Aspirin treatment improved survival ratio and stroke index, and decreased ischemically injured cell numbers in cortex. Thrombin inhibition with argatroban decreases neurodegeneration and cerebral edema following bilateral CCA:O/R in gerbils.

Fas-independent apoptosis induced by UVC in p53-mutated human epithelial tumor A431 cells through activation of caspase-8 and JNK/SAPK

A431 cells/UVC-induced apoptosis/Caspase 8/Fas/JNK/PAPK. We previously observed that p53-mutated human epithelial tumor A431 cells underwent apoptosis after ultraviolet C (UVC) irradiation through the caspases-8 and -3 pathway. Fas/FasL is known to initiate apoptosis in several cell lines via caspase-8 activation. Then, to determine if Fas/FasL mediates apoptosis in A431. we investigated Fas expression and modulation in UVC-irradiated A431 cells. A431 constitutively expressed Fas, which gradually decreased after UVC-irradiation. Pretreatment with a neutralizing anti-Fas antibody, ZB4, did not abrogate the UVC-induced apoptosis. An agonistic anti-Fas antibody, CH11, very slowly induced apoptosis in A431. suggesting that the constitutively expressed Fas had a low functional potential. Hence, UVC-induced apoptosis in A431 seems to occur independent of the Fas signal. Interestingly, however, a pretreatment with CH11 remarkably potentiated UVC-induced apoptosis. An inhibitor of caspase-8, Ac-IETD-CHO, partially inhibited UVC-induced apoptosis. JNK was phosphorylated immediately after exposure to UVC. prior to apoptotic chromatin condensation. Our data suggest that the activation of caspase-8 occurs independent of Fas upregulation, and that JNK/ SAPK contributes to UVC-induced apoptosis in human epithelial A431 cells.

Identification and characterization of B-cell epitopes of a 53-kDa outer membrane protein from Porphyromonas gingivalis

We have previously reported that Porphyromonas gingivalis FDC 381 possesses a 53-kDa protein antigen (Ag53) on its outer membrane that evokes a strong humoral immune response in many patients with periodontal disease and that the humoral immune responses to Ag53 differ greatly among patients. To understand how the individual humoral immune system against Ag53 was determined, the regions of Ag53 recognized by specific antibody (B-cell epitopes) and dominant subclasses of serum immunoglobulin G (IgG) against major B-cell epitopes were examined by enzyme-linked immunosorbent assay. This study used sera from six patients with periodontitis, which all reacted strongly with sonic extracts of P. gingivalis 381 and with purified Ag53, and sera from six periodontally healthy children, which did not react with either sonic extracts of P. gingivalis 381 or Ag53. The epitopes were identified using synthetic 5-residue overlapping decapeptides covering the entire Ag53. Thirteen of 89 synthetic decapeptides showed a strong reaction with sera from the periodontal patients, but no reaction with those from the healthy children. Four peptides of 13 exerted different immune responses among patients. Furthermore, restriction analyses of the highly antigenic regions revealed that three sequences, RAAIRAS, YYLQ and MSPARR, were identified as major B-cell epitopes. Additionally, these epitopes were recognized mainly by the IgG2 isotype. These data suggest that the difference of B-cell epitopes might influence individual differences in antibody titer against Ag53 and also that the epitopes recognized commonly by multiple antibodies are quite valuable for peptide vaccine development against P. gingivalis infection.

Heterogeneity of host immunological risk factors in patients with aggressive periodontitis

BACKGROUND

The pathogenesis of early-onset periodontitis (EOP) can be explained by various host risk factors. Previous studies have focused on a single (among many possible) immunological risk factor and the association among the factors has not been assessed. We comprehensively investigated the associations among multiple host immunological risk factors in EOP patients to further elucidate their role in the pathogenesis of EOP.

METHODS

Sixty-eight EOP patients (50 generalized EOP, 18 localized EOP), 51 EOP-suspected patients (S-EOP), 43 adult periodontitis (AP) patients, and 36 periodontally healthy subjects (HS) participated in this cross-sectional study. We examined peripheral neutrophil functions, phenotypic and functional characterization of peripheral lymphocytes (lymphocyte subsets, T-cell proliferative activity), cytokine productivity (interleukin [IL]-1, IL-2, tumor necrosis factor [TNF]-alpha, interferon [IFN]-gamma, IL-4 and IL-6), serum immunoglobulin G (IgG) antibody titers against 12 periodontal bacteria, and HLA class II genotypes.

RESULTS

G-EOP, S-EOP, and AP patient groups showed significantly lower percentages of pan T cells and CD8-positive cells (P < 0.02) compared with the HS group. L-EOP patients showed depressed IL-4 and TNF-alpha productivity compared with the HS group (P < 0.02). The EOP group showed significantly elevated antibody levels against Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, and Fusobacterium nucleatum compared with the HS group (P < 0.05). The frequency with DQB1*0503 was significantly higher in the EOP patient group than the HS group (P = 0.045) due to the higher frequency in L-EOP patients than the HS group (P = 0.035). There were wide interindividual variations in each of the tests among patient and HS groups; however, EOP patients showed wider intradiagnostic group variations in certain host defensive cell functions than the other groups. There were some EOP patients who showed extremely low or high values in some tests; the EOP patients could be further divided into subgroups according to their host defensive and immunological profiles. However, there was heterogeneity in some of the other host immunological tests even in the subgroups.

CONCLUSIONS

The association of host immunological risk factors in EOP patients is widely varied and more complex than previously thought. These results indicate the difficulty of explaining the pathogenesis of EOP based on a single host risk factor and also emphasize the importance of critical assessment of not only EOP patient groups, but also individual patients.

Prenatal radiation-induced limb defects mediated by Trp53-dependent apoptosis in mice

We reported previously that in utero radiation-induced apoptosis in the predigital regions of embryonic limb buds was responsible for digital defects in mice. To investigate the possible involvement of the Trp53 gene, the present study was conducted using embryonic C57BL/6J mice with different Trp53 status. Susceptibility to radiation-induced apoptosis in the predigital regions and digital defects depended on both Trp53 status and the radiation dose; i.e., Trp53 wild-type (Trp53(+/+)) mice appeared to be the most sensitive, Trp53 heterozygous (Trp53(+/-)) mice were intermediate, and Trp53 knockout (Trp53(-/-)) mice were the most resistant. These results indicate that induction of apoptosis and digital defects by prenatal irradiation in the later period of organogenesis are mediated by the Trp53 gene. These findings suggest that the wild-type Trp53 gene may be an intrinsic genetic susceptibility factor that is responsible for certain congenital defects induced by prenatal irradiation.