Long-term outcomes of patients with primary intestinal follicular lymphoma managed with watch-and-wait strategy

Patients with primary intestinal follicular lymphoma are often followed-up without a specific treatment, and this approach is called the "watch-and-wait approach." However, the long-term outcomes of this patient group have not been sufficiently investigated. We enrolled patients with primary intestinal follicular lymphoma who were diagnosed before 2016 and managed with the watch-and-wait approach in 20 institutions. We retrospectively investigated the overall, disease-specific, and event-free survival rates as well as the rate of spontaneous regression. Among the 248 patients with follicular lymphoma with gastrointestinal involvement, 124 had localized disease (stage I or II₁). We analyzed the data of 73 patients who were managed using the watch-and-wait approach. During the mean follow-up period of 8.3 years, the follicular lymphoma had spontaneously resolved in 16.4% of the patients. The 5-year and 10-year overall survival rates were 92.9% and 87.1%, respectively. With disease progression (n = 7), initiation of therapy (n = 7), and histologic transformation to aggressive lymphoma (n = 0) defined as events, the 5-year and 10-year event-free survival rates were 91.1% and 86.9%, respectively. No patient died of progressive lymphoma. Thus, both 5-year and 10-year disease-specific survival rates were 100%. In conclusion, an indolent long-term clinical course was confirmed in the patients with primary intestinal follicular lymphoma. The watch-and-wait strategy is a reasonable approach for the initial management of these patients.

Spontaneous intranasal tumours in rabbits: 7 cases (2007-2019)

OBJECTIVES

Neoplasms that arise in the nasal cavity are reported infrequently in rabbits. This case series aims to review and determine the clinical behaviour of neoplasms in the nasal cavity in rabbits.

MATERIALS AND METHODS

A retrospective study was conducted on seven pet rabbits diagnosed with intranasal tumours to describe the clinical and histopathological findings and prognoses after surgery and/or radiotherapy.

RESULTS

The most common clinical signs were nasal snoring when breathing, nasal discharge, and subsequent dyspnoea and anorexia. Six different histopathological types of tumours were diagnosed: intranasal adenocarcinoma, squamous cell carcinoma, osteosarcoma, carcinoid tumour, osteoma, and lymphoma. Skull radiography only revealed the abnormalities in three of seven cases but on CT, the intranasal masses were more clearly identified in all cases. All cases received tumour resection through rhinostomy and four cases received radiotherapy after surgery. In the six cases with a known outcome, the survival time after surgery was more than 13 months.

CLINICAL SIGNIFICANCE

This case series provides an insight of the behavior of intranasal neoplasms in rabbits. Surgical treatment and radiotherapy could improve their clinical sings.

Age is an independent adverse prognostic factor for overall survival in acute myeloid leukemia in Japan

AIM: To elucidate risk factors for survival of elderly acute myeloid leukemia (AML) patients in a real-world practice by observational study.

METHODS: We conducted a population-based study in 213 adult and elderly AML patients (127 males and 86 females) in Kagawa Prefecture, Japan. To construct this cohort, we gathered all data for patients diagnosed with AML at 7 hospitals in Kagawa between 2006 and 2010. The primary end point was overall survival (OS) after AML diagnosis. Unadjusted Kaplan-Meier survival plots were used to determine OS in the overall cohort. Multivariate analysis was used to determine the independent adverse prognostic factors for OS, with the covariates of interest including age, gender, race/ethnicity, CCI, education, median income, metropolitan statistical area size and history of myelodysplastic syndrome.

RESULTS: The average population of Kagawa during the study period was 992489, and the incidence of AML was 4.26 per 100000 person-years. A total of 197 patients with non-acute promyelocytic leukemia (non-APL) (119 males and 78 females) were also included. The median age of non-APL patients was 70 years (average 67, range 24-95). The 5-year OS rate was 21.1%. Subsequent analysis by age group showed that the survival rate declined with age; the 5-year OS rates of non-APL patients younger than 64 years, 65-74 years, and older than 75 years were 41.5%, 14.1%, and 8.9%, respectively. Multivariate analysis revealed that unfavorable risk karyotype, older age, poor performance status (PS) (3-4), lack of induction chemotherapy, and antecedent haematological disease were independent prognostic predictors. In the subgroup analysis, we also found that older patients with non-APL had lower complete remission rates and higher early death rates than younger patients, irrespective of PS. However, intensive chemotherapy was a significant predictor for longer survival not only in the patients < 75 years of age, but also in those over 75 with PS 0-2.

CONCLUSION: Age would contribute considerable life expectancy to indicate induction chemotherapy with eligible dose of cytotoxic drugs for a favorable case even in advanced elderly.

A case of non-Hodgkin's lymphoma primary arising in both adrenal glands associated with adrenal failure

It is known that adrenal insufficiency is one of the complications in primary adrenal lymphoma, especially those with bilateral adrenal involvement. A 73-year-old man was referred for general fatigue and high fever to the nearest hospital. The patient was transferred to our hospital for evaluation of bilateral adrenal tumors and hyponatremia. He was diagnosed as having non-Hodgkin's lymphoma (NHL) with primaries arising in both adrenal glands. Primary adrenal lymphoma (PAL) is a rare extra-nodal NHL. Although an appropriate treatment of this disease has not been established, our case has demonstrated that the combination of rituximab and THP-COP chemotherapy could be administered, and that it improved clinical manifestations. This case raises the suggestion that malignant lymphoma should be suspected in patients with bilateral adrenal tumors that present with progressive adrenal insufficiency.

Simultaneous treatment with intravenous recombinant tissue plasminogen activator and endovascular therapy for acute ischemic stroke within 3 hours of onset

BACKGROUND AND PURPOSE

Because intravenous (IV) recombinant tissue plasminogen activator (rtPA) does not always lead to a good outcome in a considerable proportion of patients, combined IV rtPA and rescue endovascular therapy (ET) have been performed in several recent studies. However, rescue therapy after completion of IV rtPA often results in late ineffective recanalization. We examined the efficacy and safety of combined IV rtPA and simultaneous ET as primary rather than rescue therapy for hyperacute middle cerebral artery (MCA) occlusion.

MATERIALS AND METHODS

A total of 29 patients eligible for IV rtPA, who were diagnosed as having MCA (M1 or M2) occlusion within 3 hours of onset, underwent thrombolysis. In the combined group, patients were treated by IV rtPA (0.6 mg/kg for 60 minutes) and simultaneous ET (intra-arterial rtPA, mechanical thrombus disruption with microguidewire, and balloon angioplasty) initiated as soon as possible. In the IV group, patients were treated by IV rtPA only.

RESULTS

The improvement of the National Institutes of Health Stroke Scale (NIHSS) score at 24 hours was 11 +/- 4.8 in the combined group versus 5 +/- 4.3 in the IV group (P < .001). In the combined group, successful recanalization was observed in 14 (88%) of 16 patients with no symptomatic intracranial hemorrhage, and 10 (63%) of 16 patients had favorable outcomes (modified Rankin Scale [mRS] 0, 1) at 3 months.

CONCLUSIONS

Aggressive combined therapy with IV rtPA and simultaneous ET markedly improved the clinical outcome of hyperacute MCA occlusion without significant adverse effect. Additional randomized study is needed to confirm our results.

Intravenous 3D digital subtraction angiography in the diagnosis of unruptured intracranial aneurysms

Recent progress in digital subtraction angiography (DSA) devices makes it possible to perform rotational angiography with high resolution and high sensitivity. We tried intravenous (IV) 3D DSA in patients who had undergone MR angiography (MRA) suggestive of unruptured intracranial aneurysms. IV 3D DSA can be used as an alternative method for imaging unruptured intracranial aneurysms suggested on MRA.

Perceived body size and desire for thinness of young Japanese women: a population-based survey

The present study describes findings in relation to perceived body size and 'desire for thinness' by age and residential areas ('metropolitan areas', 'large cities', 'small cities' and 'towns') among young Japanese women. Data on 1731 non-pregnant, non-lactating women aged 15-39 years from the 1998 National Nutrition Survey of Japan were used. Current body size was evaluated by BMI percentiles (lean, <5th; underweight, 5th or = BMI <25th; normal, 25th< or = BMI< 75th; overweight, 75th < or =BMI <95th; obese, > or =95th), calculated for 5-year age groups. Perceived body size was obtained by self-report. We defined 'overestimation' as non-overweight, non-obese women who perceived themselves as being 'overweight' or 'obese'. Desired body size was evaluated by applying the desired BMI to these cut-off points. Of all the women, 48.4% perceived themselves as being 'overweight' or 'obese', and 43.7% desired a 'lean' or 'underweight' body size. Adjusted for the current BMI, the OR for 'overestimation' calculated by a logistic regression model was significantly elevated in the 15-19-year age group (OR 2.79; 95% CI 1.76, 4.43), compared with the 25-29-year age group. The OR for 'desire for thinness' was significantly high in the 35-39-year age group (OR 2.74; 95% CI 1.93, 3.89) and the 15-19-year age group (OR 2.26; 95% CI 1.57, 3.24). Women living in metropolitan areas had higher OR for 'desire for thinness' (but not for 'overestimation') than did women in towns (OR 1.47; 95% CI 1.05, 2.07). The findings suggest the nature of excessive weight concerns of young women in Japan; thus efforts to control such health-risk behaviours at a national level are urgent.

Folate intakes and folate biomarker profiles of pregnant Japanese women in the first trimester

OBJECTIVE

To assess the status of dietary folate intake, serum and red blood cell (RBC) folate, and related nutritional biomarkers in healthy Japanese women in early pregnancy.

DESIGN

A cross-sectional, observational study.

SUBJECTS

Pregnant women in the first trimester, at 7-15 weeks gestation (n=70), who were not consuming any folate supplements or folate fortified foods.

METHODS

Three-day dietary records were obtained from each subject to assess dietary folate intake. Blood samples were collected for measurement of biomarkers. Biomarkers and nutrient intake were analyzed in two groups defined by their serum folate concentrations: the low folate group (serum folate < 9 ng/ml) and the high folate group (serum folate > or = 9 ng/ml).

RESULT

Mean serum and RBC folate concentrations in all subjects were 10.3 and 519 ng/ml, respectively. These levels were remarkably higher than the reported values from many other countries despite our subjects receiving no folic acids supplements. However, mean folate intake by our subjects from natural foods was 289 microg/day, which is thought to be low according to the Japanese dietary recommendation specified for pregnant women. The intake of spinach and fruits was significantly greater in the high folate group than in the low folate group.

CONCLUSION

Folate intake was thought to be adequate to maintain a desirable level of serum folate concentration in Japanese pregnant women in the first trimester, although the intake of folate from natural food was not high enough to meet the recommended daily intake.

Interferon-gamma independent formation of pulmonary granuloma in mice by injections with trehalose dimycolate (cord factor), lipoarabinomannan and phosphatidylinositol mannosides isolated from Mycobacterium tuberculosis

The mechanisms by which pulmonary granuloma formation is caused by administration of mycobacterial glycolipids such as trehalose dimycolate (TDM), lipoarabinomannan (LAM) and phosphatidylinositol mannosides (PIM) were investigated. When peritoneal and alveolar macrophages were stimulated with TDM, LAM and PIM in vitro, TDM exhibited the strongest tumour necrosis factor (TNF)-inducing activity. Responsiveness of macrophages from mice defected Toll-like receptor 4 (TLR4) was much higher than that of the wild-type mice. Although PIM and LAM also had a significant activity, LAM rather than PIM stimulated higher TNF-alpha production by alveolar macrophage. When mycobacterial glycolipids were injected as water-in-oil-in-water emulsion into mice via the tail vein, development of pulmonary granuloma in response to glycolipids were related closely to their TNF-inducing activity and TDM exhibited the strongest activity. Granuloma formation was observed not only in mice lacking interleukin (IL)-12 signalling but also interferon (IFN)-gamma knock-out mice. Granuloma formation caused by glycolipids correlated with TNF-alpha levels in lungs. Administration of anti-TNF-alpha monoclonal antibody into TDM-injected IFN-gamma knock-out mice decreased in granuloma formation, suggesting that development of pulmonary granuloma by mycobacterial glycolipids such as TDM is due to IFN-gamma-independent and TNF-alpha-dependent pathway.

Maternal weight gain ranges for optimal fetal growth in Japanese women

OBJECTIVE

To identify adequate weight gain ranges during pregnancy in Japanese women.

METHOD

Obstetric records from 2001 to 2002 for 46,659 term, singleton, vaginally delivered live births was used to estimate IUGR and macrosomia risk. Total maternal weight gain was grouped according to gestational age-specific percentile values of weight gain as follows: "very low" (under the 25th), "low" (25th to 49th), "moderate" (50th to 74th), "high" (75th to 89th), and "very high" (90th and over).

RESULTS

About 6% of infants were identified as having IUGR and 0.9% as macrosomia. IUGR risk was elevated with low weight gains. Macrosomia risk was related to high weight gains and previous spontaneous abortions.

CONCLUSION

Achieving weight gains between the 50th and 75th percentiles for gestational age was considered adequate for optimal fetal growth in Japanese pregnant women.

Prevalent hyper-methylation of the CDH13 gene promoter in malignant B cell lymphomas

CDH13 (H-cadherin) is a member of the cadherin superfamily, which plays an important role in cell recognition and adhesion. We examined the expression and methylation status of the CDH13 gene in diffuse large B cell lymphomas (B-DLCLs). We found decreased expression of the CDH13 gene in all of 6 hematopoietic cell lines by reverse transcription-polymerase chain reaction (RT-PCR). Promoter hyper-methylation of the gene was detected in all 6 cell lines and in 13 of 19 (68%) B-DLCL samples by methylation-specific PCR. Interestingly, the methylation frequency of the CDH13 gene was comparable to those of the tumor suppressor genes p15 (68%) and p16 (74%) detected in B-DLCLs. Sequencing of bisulfite-treated DNA revealed hyper-methylation of the CpG islands of the CDH13 promoter in B-DLCLs and the cell lines. Treatment with 5-aza-2'-deoxycytidine restored CDH13 gene expression in a cell line in which promoter hyper-methylation and impaired expression of the CDH13 gene were observed. Loss of heterozygosity (LOH) around the CDH13 gene on chromosome 16q24 was detected in 6 of 15 (40%) informative cases with microsatellite marker D16S507 and in 6 of 15 (40%) cases with D16S422 in B-DLCLs. In all of 4 B-DLCL cases which showed both promoter methylation and LOH at the two marker loci, expression of the CDH13 gene was significantly low. These results suggest that silencing of the CDH13 gene by aberrant promoter methylation and allelic deletion is associated with tumorigenesis in a subset of B-DLCL.

Carbon dioxide insufflation for chronic subdural haematoma: a simple addition to burr-hole irrigation and closed-system drainage

Burr-hole irrigation with closed-system drainage is a common surgical method used for chronic subdural haematoma. However, the subdural space with air that entered during surgery sometimes remains for a prolonged period after surgery and may hamper uncomplicated healing of the subdural space. We combined a simple procedure, insufflation of carbon dioxide (CO2) into the subdural space through a drainage catheter, with conventional burr-hole irrigation and closed-system drainage. By this additional procedure, both the subdural space and the gas within the space decreased rapidly, and the subdural drain could be removed within 24 h. By promoting obliteration of the subdural space, this simple combined technique may contribute to early recovery and discharge of patients, and to a reduction in the recurrence rate of the disease.

Can t(8;21) oligoblastic leukemia be called a myelodysplastic syndrome?

The new World Health Organization (WHO) classification of hematologic malignancies has incorporated t(8;21) myelodysplastic syndromes (MDS) according to the French-American-British classification into the category of acute myeloid leukemia (AML) with t(8;21)(q22;q22), while our knowledge about clinicopathological features of t(8;21) oligoblastic leukemia is still limited. We present our experience with 12 patients meeting the FAB diagnostic criteria of MDS and having t(8;21), who were compared to 43 t(8;21) AML patients. The MDS and AML patients shared most hematomorphologic, immunophenotypic, and clinical features, whereas the differences lay along myeloid maturation. The MDS patients had higher percentages of circulating neutrophils and marrow myeloid cells beyond promyelocytes than the AML patients. The incidence of Auer rods in mature neutrophils in MDS was significantly higher than that in AML, and furthermore, the neutrophils in MDS more commonly contain t(8;21) than in AML. Our findings support the rationale for the WHO classification, and future studies on large patient populations should help clarify whether the spontaneous differentiation potential could be actively associated with a hematological manifestation of t(8;21) leukemias.

Prediction of subsequent relapse in children with steroid-sensitive nephrotic syndrome

Among nephrotic children with frequent relapses at risk for cumulative steroid toxicity, identification of children who may be at high risk for subsequent relapse is very important in making the decision to introduce cytotoxic drugs. We examined the clinical course of 467 relapses in 121 steroid-sensitive nephrotic children to elucidate the risk factors for subsequent relapse, using the Cox proportional-hazards regression model. Gender, age at onset, duration of illness from onset, prednisolone dosage at the most-recent relapse, and regimens of initial steroid therapy at onset were not associated with risk. Relapse within the 1st year was a powerful independent predictor of subsequent relapse irrespective of the duration of illness. The hazard ratio of patients with more than one relapse within the 1st year increased to 1.72-2.12 compared with those without a relapse within the 1st year. The remission period just before the most-recent relapse was also a significant predictor. The risk for patients with a 1-year or longer remission period decreased to 0.57. Patients treated with cyclophosphamide for 12 weeks had a significantly longer remission than those treated with prednisolone alone. Our results suggest that early relapse after onset and/or a short remission period just before recent relapse are independent risk factors for subsequent relapse. Cytotoxic therapy has serious adverse effects and its effect may be limited. Our results may be helpful in deciding on the suitability of cytotoxic drugs.

Mycobacterial cord factor, but not sulfolipid, causes depletion of NKT cells and upregulation of CD1d1 on murine macrophages

Trehalose 6,6'-dimycolate (TDM, cord factor) has frequently been used as an adjuvant to stimulate antibody production. Although it also induces cellular immunity, detailed studies about the underlying events do not exist. To determine the kinetics of TDM-specific changes promoting a T helper 1 (Th1) response, we injected mice with TDM or 2,3,6,6'-tetraacyl trehalose 2'-sulfate (SL, sulfolipid), another mycobacterial trehalose-containing glycolipid without mycolic acid. TDM, but not SL, caused a strong increase in serum interferon-gamma (IFN-gamma) levels 2 days later, accompanied by expansion of natural killer (NK) cells. Subsequent TDM effects included depletion of normal-density CD4(+) NK1.1(+) TCRalpha/beta(intermediate) cells from day 7 on, upregulation of MHC class II and CD1d1 on macrophages (peaking on day 21), and an increased proportion of Th1 cells evident after 3 weeks. TDM, but not a similar glycolipid without mycolic acid, can therefore initiate a cascade of events starting with strong release of IFN-gamma and NK cell expansion, resulting in the appearance of macrophages activated for antigen presentation. Our data therefore provide the basis for optimized immunization schedules with TDM as the adjuvant component of a Th1 vaccine.

[A case of suspected pulmonary air embolism in endoscopic neurosurgery]

Sudden reduction in end-tidal PCO2 and SpO2 occurred during the endoscopic third ventriculostomy in a patient with hydrocephalus under general anesthesia. We suspect that it was caused by pulmonary air embolism. A 63-year-old female was scheduled for endoscopic third ventriculostomy under general anesthesia. Endoscopic manipulation caused hemorrhage from chorioid plexus 21 minutes after the procedure was begun, and intraventricular irrigation was performed to achieve hemostasis. In the subsequent 3 minutes, end-tidal PCO2 declined from 26 mmHg to 15 mmHg (PaCO2 39.6 mmHg), and SpO2 declined from 98% to 92% (PaO2 69.2 mmHg). Nitrous oxide was discontinued immediately because pulmonary air embolism was suspected and the oxygen concentration was increased to 100%. At the same time the surgical procedure was discontinued. After 15 minutes, end-tidal PCO2 recovered to 25 mmHg, and SpO2 recovered to 98% (PaO2 136.5 mmHg), and surgery was resumed. The patient recovered from anesthesia. The chest X-p at the end of operation, and pulmonary scintigraphy on the following day revealed no abnormal findings, but brain CT demonstrated a large quantity of air in both lateral ventricles.

Persistent infection with Listeria monocytogenes in the kidney induces anti-inflammatory invariant fetal-type gammadelta T cells

After intraperitoneal inoculation with Listeria monocytogenes, gammadelta T cells appear in the peritoneal cavity preceding the appearance of alphabeta T cells. Such gammadelta T cells predominantly express T-cell receptor (TCR)Vgamma1/Vdelta6, develop through an extrathymic pathway, and contribute to host defence against the bacteria. We have observed a gradual increase in gammadelta T cells in kidneys of mice after intrarenal inoculation with L. monocytogenes, which resulted in an unusually long-lasting local infection. In this study, we examined the characteristics and the roles of the gammadelta T cells induced in this model. It was found that these gammadelta T cells predominantly expressed TCRVgamma6/Vdelta1 with canonical junctional sequences identical to those expressed on fetal thymocytes. Although depletion of such gammadelta T cells in vivo did not affect the number of bacteria, it resulted in histologically exacerbated inflammation in the kidneys. These results indicate that a persistent infection with L. monocytogenes in kidneys induces a different kind of gammadelta T cell from that induced after intraperitoneal infection. The former expresses invariant fetal-type Vgamma6/Vdelta1+TCR and plays a regulatory role in resolution of inflammation.

Development of dendritic epidermal T cells with a skewed diversity of gamma delta TCRs in V delta 1-deficient mice

One of the most intriguing features of gammadelta T cells that reside in murine epithelia is the association of a specific Vgamma/Vdelta usage with each epithelial tissue. Dendritic epidermal T cells (DETCs) in the murine epidermis, are predominantly derived from the "first wave" Vgamma5+ fetal thymocytes and overwhelmingly express the canonical Vgamma5/Vdelta1-TCRs lacking junctional diversity. Targeted disruption of the Vdelta1 gene resulted in a markedly impaired development of Vgamma5+ fetal thymocytes as precursors of DETCs; however, gammadeltaTCR+ DETCs with a typical dendritic morphology were observed in Vdelta1-/- mice and their cell densities in the epidermis were slightly lower than those in Vdelta1+/- epidermis. Moreover, the Vdelta1-deficient DETCs were functionally competent in their ability to up-regulate cytokines and keratinocyte growth factor-expression in response to keratinocytes. Vgamma5+ DETCs were predominant in the Vdelta1-/- epidermis, though Vgamma5- gammadeltaTCR+ DETCs were also detected. The Vgamma5+ DETCs showed a typical dendritic shape, gammadeltaTCR(high), and age-associated expansion in epidermis as observed in conventional DETCs of normal mice, whereas the Vgamma5- gammadeltaTCR+ DETCs showed a less dendritic shape, gammadeltaTCR(low), and no expansion in the epidermis, consistent with their immaturity. These results suggest that optimal DETC development does not require a particular Vgamma/Vdelta-chain usage but requires expression of a limited diversity of gammadeltaTCRs, which allow DETC precursors to mature and expand within the epidermal microenvironment.

Ineffective control of murine cytomegalovirus by IE1-specific cytotoxic T lymphocytes during protracted infection in the lung

Interstitial pneumonia caused by cytomegalovirus (CMV) is a fatal disease in immunocompromised patients. In order to examine the defense mechanism against the virus in the lung, we employed an intratracheal infection model in susceptible mice. In mice infected intratracheally with murine CMV, a protracted infection was observed where infectious virus was detected up to 21 days of infection. During this prolonged infection, massive accumulation in the lung of CD8+ T cells with activated phenotypes occurred and these CD8+ T cells showed direct ex vivo cytolytic activity against target cells pulsed with the nonamer peptide derived from IE1 protein of the virus, which has been shown to be the dominant epitope recognized by most of virus-specific CTL. Moreover, adoptive transfer of in vitro induced IE1 peptide-specific CTL line showed no anti-virus effect in the lung, although they were effective in the spleen. Hence, there is reason to assume the IE1-specific CTL induced in vivo or in vitro plays limited roles during the prolonged infection in the lung.

Characterization of CD4- CD8- CD3+ T-cell receptor-alphabeta+ T cells in murine cytomegalovirus infection

In this study, we have investigated that after the intraperitoneal infection with murine cytomegalovirus (MCMV), the CD3+ CD4- CD8-(double negative; DN) T-cell receptor (TCR)alphabeta+ T cells increased in peritoneal cavity, liver and spleen in both resistant C57BL/6 and susceptible BALB/c mice. The total cellular population of these cells showed peak levels around day 5 after infection in all the three investigated organs and the following phenotypical and functional characteristics emerged. The peritoneal DN TCRalphabeta+ T cells expressed highly skewed TCRVbeta8 on day 5 after infection compared with the uninfected mice, but those in spleen and liver showed moderate and low skewed TCRVbeta8, respectively. The percentages of NK1.1+ DN TCRalphabeta+ T cells gradually decreased as did modulation of some of their activation markers consistent with an activated cell phenotype. The peritoneal DN TCRalphabeta+ T cells on day 5 after infection expressed the genes of interferon-gamma (IFN-gamma), tumour necrosis factor-alpha, Eta-1 (early T-cell activation-1) and MCP-1 (monocyte chemoattractant protein 1) but lacked expression of interleukin-4 (IL-4). After in vitro stimulation with phorbol 12-myristate 13-acetate and calcium ionophore in the presence of Brefeldin A, higher frequencies of intracellular IFN-gamma+ DN TCRalphabeta+ T cells were detected in all three investigated organs of infected mice compared with those of uninfected mice. Stimulation of peritoneal DN TCRalphabeta+ T cells with plate-bound anti-TCRbeta monoclonal antibodies showed proliferation and also produced IFN-gamma but not IL-4. These results suggest that DN TCRalphabeta+ T cells were activated and may have an antiviral effect through producing IFN-gamma and some macrophage-activating factors during an early phase of MCMV infection.

Structure of the human retinoblastoma-related p107 gene and its intragenic deletion in a B-cell lymphoma cell line

The human p107 protein shares many structural and functional features with the retinoblastoma gene product and retinoblastoma-related p130 protein. In this study, we have cloned and elucidated the complete intron-exon organization of the gene encoding the p107 protein. The gene contains 22 exons spanning over 100kilobase pairs of genomic DNA. The length of individual exons ranges from 50 to 840base pairs. The arrays of exons in the p107 gene are rather similar among members of the gene family, especially to those of the p130 gene, while the length of introns is extensively diverse. This study will provide a molecular basis for implementing comprehensive screening for p107 mutations using genomic DNAs from human malignancies. We also show a detailed structure of an intragenic deletion of the p107 gene found in a human B-cell lymphoma cell line, KAL-1, which was shown to occur by homologous recombination between the two directly repeated Alu family sequences.

Vgamma1+ gammadelta T cells play protective roles at an early phase of murine cytomegalovirus infection through production of interferon-gamma

Cytomegalovirus (CMV) causes severe opportunistic infection in immunocompromised hosts. The importance of conventional alphabeta T cells in protection against CMV infection has been well documented. However, the role of the second T-cell population (which express the gammadelta T-cell receptor) in CMV infection is not known. In the present study, we analysed the function and protective role of gammadelta T cells in a murine cytomegalovirus (MCMV) infection model. After intraperitoneal infection with MCMV, the number of gammadelta T cells increased in the liver and peritoneal cavity from day 3, and reached a peak on day 5. The gammadelta T cells showed an activated T-cell phenotype and predominantly expressed Vgamma1, which is known to be expressed by heat-shock protein 65 (hsp 65)-specific gammadelta T cells. Analysis of cytokine expression demonstrated that the MCMV-induced gammadelta T cells expressed interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) but not interleukin-4 (IL-4), implying their participation in the cell-mediated immune response against MCMV. Depletion of gammadelta T cells by anti-T-cell receptor (TCR) gammadelta monoclonal antibody (mAb) treatment resulted in significant increase of virus titre and decrease of IFN-gamma in the liver on day 3 after MCMV infection, which further supports the importance of gammadelta T cells in early protection against infection. Finally, the MCMV-induced gammadelta T cells produced IFN-gamma in vitro in response to hsp 65. Our results suggest that gammadelta T cells participate in early protection against MCMV infection through recognition of hsp 65 and production of IFN-gamma.

Accelerated recovery from cyclophosphamide-induced leukopenia in mice administered a Japanese ethical herbal drug, Hochu-ekki-to

The effect of a Japanese ethical herbal drug, Hochu-ekki-to (HOT), on recovery from leukopenia induced by cyclophosphamide (CY) was investigated. Daily oral administration of 1000 mg/kg HOT into CY-treated mice significantly prevented decrease of leukocyte numbers in the peripheral blood and accelerated recovery from leukopenia. Ginsenoside Rgl extracted from Ginseng radix, a major herb of HOT, was one of the active ingredients. HOT increased numbers of neutrophils and monocytes in the peripheral blood compared with CY-treated control. Moreover, HOT augmented the resistance against Pseudomonas aeruginosa infection. The number of colony-forming units in the spleen (CFU-S) also increased in HOT-treated mice. The frequencies of IL-3-, GM-CSF- and IFN-gamma-producing cells increased in the spleen, bone marrow, liver and IEL on HOT treatment, and HOT clearly augmented the expressions of IL-3, GM-CSF and IFN-gamma mRNA in the spleen, bone marrow, liver and IEL except IL-3 and IFN-gamma mRNA in the IEL. These results suggest that HOT enhances the production of hematopoietic lymphokines, stimulates the proliferation of hematopoietic progenitor cells and consequently accelerates recovery from leukopenia in CY-treated mice. Additionally, IFN-gamma which HOT-augmented the production may contribute the protective effect against the bacterial infection by activating of phagocyte cells.

[Age-related differences in IgA nephropathy]

To clarify age-related differences in the characteristics of IgA nephropathy, we investigated 117 patients of all ages. The number of patients in the second decade of age was larger than that in the other age decades. There was no difference in sex in all age brackets. About one half of the patients under ten years of age presented as acute nephritis, but their prognosis was favorable. Patients over 10 years, most of whom were detected by chance, tended to have a greater degree of proteinuria, a lesser degree of creatinine clearance, a higher frequency of hypertension, and a higher level of serum cholesterol with age. Although the intensity of mesangial cell proliferation was not changed, the grade of glomerulosclerosis, interstitial change, and arteriosclerosis increased and the prognosis became poor as age advanced. Treatment with corticosteroids and antiplatelet agents was less effective in adults, especially in the older age brackets than in children because the frequency of histologically chronic lesions increased. In these cases, lipid-lowering agents and angiotensin-converting enzyme inhibitors may be helpful in preventing the progression.

Decreases in Ikaros activity correlate with blast crisis in patients with chronic myelogenous leukemia

Gene targeting studies in mice have shown that the lack of Ikaros activity leads to T-cell hyperproliferation and T-cell neoplasia, establishing the Ikaros gene as a tumor suppressor gene in mice. This prompted us to investigate whether mutations in Ikaros play a role in human hematological malignancies. Reverse transcription-PCR was used to determine the relative expression levels of Ikaros isoforms in a panel of human leukemia/lymphoma cell lines and human bone marrow samples from patients with hematological malignancies. Among the cell lines examined, only BV-173, which was derived from a chronic myelogenous leukemia (CML) patient in lymphoid blast crisis, overexpressed the dominant-negative isoform, Ik-6. In 9 of 17 samples of patients in blast crisis of CML, Ikaros activity had been reduced either by drastically reducing mRNA expression (4 of 17) or by overexpressing the dominant-negative isoform Ik-6 (5 of 17). Significantly, expression of Ikaros isoforms seemed normal in chronic phase CML patients and patients with other hematological malignancies. In some cases, overexpression of the dominant-negative Ik-6 protein was confirmed by Western blot analysis, and Southern blot analysis indicated that decreases in Ikaros activity correlated with a mutation in the Ikaros locus. In summary, these findings suggest that a reduction of Ikaros activity may be an important step in the development of blast crisis in CML and provide further evidence that mutations that alter Ikaros expression may contribute to human hematological malignancies.

Application of a rigid endoscope to the microsurgical management of 54 cerebral aneurysms: results in 48 patients

OBJECT

To enhance visual confirmation of regional anatomy, endoscopy was introduced during microsurgery for cerebral aneurysms. The risks and benefits are analyzed in the present study.

METHODS

The endoscopic technique was used during microsurgery for 54 aneurysms in 48 patients. Forty-three aneurysms were located in the anterior circulation and 11 were in the posterior circulation. Thirty-eight aneurysms (70.4%) had not ruptured. All ruptured aneurysms in the present series produced Hunt and Hess Grade I or II subarachnoid hemorrhage. After initial exposure achieved with the aid of a microscope, the rigid endoscope was introduced to confirm the regional anatomy, including the aneurysm neck and adjacent structures. The necks of 43 aneurysms were clipped using microscopic control or simultaneous microscopic/endoscopic control. After clipping, the positions of the clip and nearby structures were inspected using the endoscope. Use of the neuroendoscope provided useful information that further clarified the regional anatomy in 44 cases (81.5%) either before or after neck clipping. In nine cases (16.7%), these details were available only with the use of the endoscope. In five cases (9.3%), the surgeons reapplied the clip on the basis of endoscopic information obtained after the initial clipping. There were two cases in which surgical complications were possibly related to the endoscopic procedures (one patient with asymptomatic cerebral contusion and another with transient oculomotor palsy).

CONCLUSIONS

It is the authors' impression that the use of the endoscope in the microsurgical management of cerebral aneurysms enhanced the safety and reliability of the surgery. However, there is a prerequisite for the surgeon to be familiar with this instrumentation and fully prepared for the risks and inconveniences of endoscopic procedures.

UK-2A,B,C and D, novel antifungal antibiotics from Streptomyces sp.517.02. V. Inhibition mechanism of bovine heart mitochondrial cytochrome bc1 by the novel antibiotic UK-2A

UK-2A is a potent antifungal antibiotic isolated from Streptomyces sp. 517-02 and its structure is highly similar to that of antimycin A. We investigated the inhibition mechanism of bovine heart mitochondrial cytochrome bc1 complex by the UK-2A using antimycin A and myxothiazol as the reference inhibitors of ubiquinol oxidation (Qo) and ubiquinone reduction (Qi) sites, respectively. The inhibitory potency of UK-2A was about 3-fold less than antimycin A. On the basis of the effects of UK-2A on the reduction kinetics of b and c1 hemes, this compound appeared to be an inhibitor of the Qi site. However, since spectral changes of dithionite-reduced cytochrome b induced by UK-2A binding differed from that of antimycin A, the precise binding manner of UK-2A to the enzyme is not identical to that of antimycin A. It could be concluded that antimycin A binding to cytochrome b is primarily decided by structural specificity of the salicylic acid moiety.

Retrograde temporal order amnesia resulting from damage to the fornix

Some amnesic patients show an impairment of temporal order memory that cannot be accounted for by content memory deficits. The performance of an amnesic patient on memory tasks assessing the patient's content and temporal memories for remotely acquired material is described, after a lesion including the bilateral anterior fornix and adjacent anterior thalamus. The patient displayed a deficit in the temporal order tasks for remotely acquired information. Neither frontal cognitive deficits nor recognition deficits can account for this patient's poor temporal memory. This retrograde temporal order memory impairment without content memory deficits were not seen in previously reported thalamic amnesic patients. Accordingly, the present patient's poor retrograde temporal memory could hardly be explained by only a thalamic lesion. It is concluded that the patient's impairment of temporal order memory for the retrograde material is probably due to the direct disconnection between the frontal lobe and the hippocampus by disruption of the fornix.

UK-2A, B, C and D, novel antifungal antibiotics from Streptomyces sp. 517-02. IV. Comparative studies of UK-2A with antimycin A3 on cytotoxic activity and reactive oxygen species generation in LLC-PK1 cells

UK-2A, a novel antifungal antibiotic, is a structural relative of antimycin A3 (AA) and its mode of action is similar to that of AA which inhibits mitochondrial electron transport at complex III. In spite of their structural resemblance, AA had strong cytotoxicity while UK-2A had little cytotoxicity against LLC-PK1 cells as well as other types of cultured cells. When cells were treated with UK-2A or with AA the intracellular ATP content decreased significantly within 5 minutes in glucose-free medium to almost the same extent in both cases. Moreover, under the same conditions, UK-2A killed cells at a similar rate to AA. This suggested that UK-2A entered into the cells and, like AA, inhibited mitochondrial electron transport. On the other hand, AA stimulated reactive oxygen species (ROS) production within 5 minutes even at a low concentration of 1 microM whereas UK-2A did not show such an effect. The difference in the ROS-producing abilities of UK-2A and AA may account for the different cytotoxic effects of the two compounds.

Hematopoietic progenitor cells from allogeneic bone marrow transplant donors circulate in the very early post-transplant period

Despite the therapeutic efficacy of allogeneic bone marrow transplantation (allo-BMT), circulating hematopoietic progenitor cells after bone marrow transplantation have not been well characterized. In the present study, we focused on these 'post-transplant circulating progenitor cells (PTCPC)' which may be on their way to bone marrow. We analyzed the number of myeloid progenitor cells (CFU-GM) per 10 ml of peripheral blood (PB) on days 0 (just before transplantation), 1 (8-15 h after the completion of transplantation), 2, 3, 5, 7, 10, 14, 17, 21, 28 and 35 after allo-BMT in five transplant patients using a standard methylcellulose assay. In addition, high proliferative potential colony-forming cells (HPP-CFC) of the harvested donor bone marrow (BM) and day 1 PB of recipients were assayed in five patients. The origin of HPP-CFC from day 1 PB was analyzed by polymerase chain reaction of a DNA region containing a variable number of tandem repeats. The replating potential of these HPP-CFC was evaluated by a secondary colony assay. The proportion of CD38negative cells among CD34+ cells in the harvested BM and day 1 PB was evaluated by two-color flow cytometric analysis. The number of CFU-GM on day 1 ranged from 6 to 73/10 ml PB, and became undetectable on day 5. The reappearance of PTCPC was observed on day 14, along with hematopoietic recovery. The proportion of HPP-CFC among myeloid colonies from day 1 PB was significantly higher than that from harvested BM (44.3+/-10.4% vs 11.3+/-2.1%, respectively, n=5, P=0.0030). These HPP-CFC from day 1 PB were confirmed to be of donor origin. More than 90% of these HPP-CFC had replating potential. Two-color flow cytometric analysis revealed that the proportion of CD34+CD38negative cells was significantly higher in day 1 PB than in the harvested BM (61.0+/-16.5% vs 9.3+/-3.5%, respectively, n=7, P=0.0002). These observations suggest that both primitive and committed transplanted myeloid progenitor cells may circulate in the very early period following allo-BMT.

Protective effects of hochu-ekki-to, a Chinese traditional herbal medicine against murine cytomegalovirus infection

The innate immunity against murine cytomegalovirus (MCMV) at the early phase of infection is mediated by NK cells and macrophages. We studied the effects of hochu-ekki-to (HET), a traditional Chinese herbal medicine, on the regulation of innate immunity mediated by NK cells and macrophages. We found the oral administration of HET to increase both the number of leukocytes in the spleen and liver and the splenic NK cell cytotoxicity associated with the increased induction of serum IFN-alpha/beta after an MCMV infection but it had no effect on liver NK cells. However, no differences were found in the serum IL-12, IFN-gamma, TNF-alpha and nitric oxide (NO) production in the culture of macrophages between the HET- and PBS-treated mice on day 2 after MCMV infection. In addition, HET-treated splenic and peritoneal macrophages were found to show a higher intrinsic resistance against in vitro MCMV infection than that of PBS-treated mice. Therefore, the HET-induced effects on NK cells and macrophages selectively reduced the viral load in the spleen but not in the liver at an early phase of MCMV infection. HET may thus be useful in the treatment of human cytomegalovirus infection which commonly occurs in HIV-infected AIDS patients.

Genetic evidence for functional redundancy of Platelet/Endothelial cell adhesion molecule-1 (PECAM-1): CD31-deficient mice reveal PECAM-1-dependent and PECAM-1-independent functions

Platelet/endothelial cell adhesion molecule-1 (PECAM-1; CD31), a member of the Ig superfamily, is expressed strongly at endothelial cell-cell junctions, on platelets, and on most leukocytes. CD31 has been postulated to play a role in vasculogenesis and angiogenesis, and has been implicated as a key mediator of the transendothelial migration of leukocytes. To further define the physiologic role of CD31, we used targeted gene disruption of the CD31 gene in embryonic stem cells to generate CD31-deficient mice. CD31-deficient mice (CD31KO) are viable and born at the expected Mendelian frequency, remain healthy, and exhibit no obvious vascular developmental defects. In response to inflammatory challenge, polymorphonuclear leukocytes of CD31KO mice are arrested between the vascular endothelium and the basement membrane of inflammatory site mesenteric microvessels, confirming a role for CD31 in the migration of neutrophils through the subendothelial extracellular matrix. Normal numbers of leukocytes are recovered from inflammatory sites in CD31KO mice, however, suggesting that the defect in leukocyte migration across basal lamina observed in the absence of CD31 may be compensated for by the use of other adhesion molecules, or possibly an increased rate of migration. Homing of T lymphocytes in vivo is normal, and CD31KO mice are able to mount a cutaneous hypersensitivity response normally. In addition, CD31-mediated homophilic adhesion does not appear to play a role in platelet aggregation in vitro. This study provides genetic evidence that CD31 is involved in transbasement membrane migration, but does not play an obligatory role in either vascular development or leukocyte migration.

Localization of rat FGF-5 protein in skin macrophage-like cells and FGF-5S protein in hair follicle: possible involvement of two Fgf-5 gene products in hair growth cycle regulation

It has been reported that the gene for murine fibroblast growth factor-5 (Fgf-5) is expressed in the rat hair follicle and that this expression may be associated with catagen induction (Hebert et al, 1994). In this study, we analyzed the Fgf-5 gene product in skin because the gene generates two mRNA that translate into the FGF-5 protein and a short form of the FGF-5 protein (FGF-5S) as a result of an alternative splicing (Hattori et al, 1996; Ozawa et al, 1996). Indeed, we detected both types of FGF-5 mRNA in rat skin samples. Two monoclonal anti-FGF-5 antibodies, one (E723) being specific for FGF-5 long-form protein and the other (B2B6) being reactive with both FGF-5 and FGF-5S proteins, were used to locate these proteins by immunohistochemistry. Staining of the rat skin revealed that only the B2B6 antibody reacted with hair follicles and that both antibodies reacted with macrophage-like round cells, suggesting that the product of the Fgf-5 gene in the hair follicle is FGF-5S. The immunoreactivity of the FGF-5S protein increased during early anagen VI and decreased rapidly during catagen. The density of FGF-5-positive macrophage-like cells in the dermis increased during anagen and decreased during catagen and telogen, whereas the density of these cells in the panniculus adiposus did not change during anagen and increased during catagen and telogen. There was no apparent association between the density of FGF-5-positive macrophage-like cells and that of FGF-5-negative, dendritic macrophage-like cells. Thus, the results suggest the possible involvement of FGF-5S in the hair follicle in anagen VI and catagen development and that the density of FGF-5-positive macrophage-like cells may also be associated with the hair growth cycle.

Role of macrophages in acute murine cytomegalovirus infection

It has been recognized that macrophages play an important role in controlling virus infection in experimental animal models. To evaluate the role of macrophages in acute murine cytomegalovirus infection, macrophages in the spleen and the liver were eliminated by an intravenous injection of liposomes containing a cytolytic agent, dichloromethylene diphosphonate. The depletion of macrophages led to a significant increase of virus titer in the spleen and lungs in both susceptible BALB/c and resistant C57BL/6 mice during the first three days after intravenous infection. In the spleen, the increase of virus titer in macrophage-depleted BALB/c mice was much greater than that in NK cell-depleted mice. These results suggest that macrophages contribute to protection mainly by the mechanisms which are independent of NK cells during the first three days after infection. The increase of virus titer in macrophage-depleted C57BL/6 mice was as great as that in NK cell-depleted mice because of the high contribution of NK cells to protection in C57BL/6 mice. In the liver in both strains of mice, the effects of macrophage depletion on virus titer were not as much as those in the spleen and lungs. Furthermore, the local depletion of peritoneal macrophages resulted in a great increase of virus titer in the spleen at three days after intraperitoneal infection. We conclude that macrophages greatly contribute to decreasing the virus load in some organs possibly through either or both intrinsic and extrinsic mechanisms in the early phase of primary infection with murine cytomegalovirus.

[Apoptosis of peripheral leukocytes in patients with myelodysplastic syndromes]

Apoptosis of peripheral leukocytes in 9 patients with myelodysplastic syndromes (MDS) was examined in vitro, using peripheral blood that had been gently incubated at 37 degrees C for 5 hours. The MDS patients included 3 with refractory anemia, 2 with refractory anemia with ringed sideroblasts, and 4 with refractory anemia with excess blasts. Peripheral blood specimens were also obtained from a control group consisting of 10 patients with iron deficiency anemia (IDA), 10 with idiopathic thrombocytopenic purpura (ITP) and 10 healthy individuals. Apoptotic granulocytes (Apo-Gs) were identified by morphological changes, including nuclear fragmentation, and expressed as a percentage of every 300 granulocytes counted. Apo-Gs were counted 1, 2, 3, 4, and 5 hours after incubation. Although the percentage of apo-Gs climbed over time in the MDS patients, a small number of apo-Gs were also observed in the healthy individuals. In the MDS patients, the proportions of apo-Gs 5 hours after incubation (37 degrees C) were significantly higher than those in the IDA and ITP patients and healthy individuals (15.7 +/- 8.0% in MDS patients vs. 2.8 +/- 1.2% in IDA patients, 2.3 +/- 1.7% in ITP patients, and 0.7 +/- 0.6% in healthy individuals; p < 0.005). No significant differences were observed in the proportions of apo-lymphocytes. DNA fragments were observed in blood lymphocyte from an MDS patient examined. Negative correlations between the percentages of granulocytes and Apo-Gs tended to be observed in the MDS patients. These results suggest that a strong susceptibility to peripheral granulocyte apoptosis is one of possible causes of granulocytopenia in MDS patients.

Genetic alterations in the retinoblastoma protein-related p107 gene in human hematologic malignancies

Genetic alterations in the p107 gene, a close relative of the retinoblastoma tumor suppressor gene, have never been identified in human malignancies. When we searched for such alterations in human hematologic malignancies by Southern blot analysis, 2 of 21 cell lines and 1 of 88 primary disorders had genomic alterations within the gene. Particularly, an altered p107 gene in a diffuse-large B-cell lymphoma cell line, KAL-1, harbored an intragenic deletion of about 15 kbp leading to the expression of an altered p107 mRNA devoid of 819 nucleotides of the coding sequences, which predicts to encode an approximately 87-kDa protein. This cell line was found to express solely a p107 derivative of 84 kDa by immunoblotting analysis. These results suggest that alterations in the p107 gene are probably related to a limited subset of human hematologic malignancies.

Positive selection of extrathymically developed T cells by self-antigens

Most T cells develop through the thymus, where they undergo positive and negative selection. Some peripheral T cells are known to develop in the absence of thymus, but there is insufficient information about their selection. To analyze the selection of extrathymically developed T cells, we reconstituted thymectomized male or female recipient mice with bone marrow cells of mice transgenic for male H-Y antigen-specific T cell receptor (TCR). It was revealed that the T cells bearing self-antigen-specific TCR were not deleted in thymectomized male recipients. More importantly, the absence of H-Y antigen-specific T cells in thymectomized female recipients suggests positive selection of extrathymically developed T cells by the self-antigen. The extrathymically developed T cells in male mice expressed interleukin (IL)-2 receptor beta chain (IL-2Rbeta) and intermediate levels of CD3 (CD3(int)) but were natural killer cell (NK)1.1(-). They rapidly produced interferon gamma but not IL-4 after TCR cross-linking. Furthermore, a similar pattern of cytokine production was observed in CD3(int)IL-2Rbeta+NK1.1(-) cells in normal mice which have been shown to develop extrathymically. These results suggest that extrathymically developed CD3(int)IL-2Rbeta+NK1. 1(-) cells in normal mice are also positively selected by self-antigens.

Transendothelial migration and trafficking of leukocytes in LFA-1-deficient mice

The leukocyte integrin LFA-1 plays an important role in leukocyte trafficking and the immune response. Using LFA-1-deficient mice, we demonstrate that LFA-1 regulates the trafficking of lymphocytes to peripheral lymph nodes, and, to a lesser degree, to mesenteric lymph nodes and acute inflammatory sites. LFA-1, either because of its role in initial adhesion and/ or the passage of leukocytes across endothelial cells, plays a vital role in T lymphocyte and neutrophil transendothelial migration. Neutrophils and activated T lymphocytes from LFA-1-deficient mice were unable to cross endothelial cell monolayers in response to a chemokine gradient, whereas wild-type (WT) T lymphocytes and neutrophils were capable of migration. By contrast, LFA-1-deficient T lymphocytes displayed normal chemotaxis to the same chemokine. Our studies with LFA-1-deficient monocytes indicate that LFA-1 acts in concert with complement receptor 3 to mediate transendothelial migration of these cells, as anti-CD18 monoclonal antibodies (mAb) blocked both WT and LFA-1-deficient monocyte transendothelial migration, whereas anti-CD11 b mAb preferentially blocked transendothelial migration of LFA-1-deficient monocytes. Finally, whereas anti-CD31 mAb blocked WT monocyte and neutrophil transendothelial cell migration they did not block LFA-1-deficient monocyte and neutrophil transendothelial migration.

Myelodysplastic syndrome with translocation (8;21): a distinct myelodysplastic syndrome entity or M2-acute myeloid leukemia with extensive myeloid maturation?

We report a case of refractory anemia with excess of blasts in transformation with the translocation (8;21), which is frequent in acute myeloid leukemia (AML) but not in myelodysplastic syndromes (MDS). Bone marrow blasts were 1.6% and an extensive myeloid differentiation was noted. Fluorescence in situ hybridization analysis revealed the presence of 21q22 translocations in mature neutrophils, indicating that clonogenic blast progenitors could actively undergo terminal differentiation to mature end cells in vivo. We consider that t(8;21)+ MDS may represent a rare clinical manifestation of M2-AML, in which blast progenitors have an extensive differentiation potential to mature neutrophils without maturation arrests.

Glioblastoma following radiotherapy in a patient with tuberous sclerosis

A 26-year-old male with tuberous sclerosis developed a glioblastoma in the right temporal lobe 8 years after surgical excision and irradiation of a subependymal giant cell astrocytoma. The glioblastoma was probably an irradiation-induced tumor. Irradiation should not be given routinely for subependymal giant cell astrocytoma.

Role of the NF-ATc transcription factor in morphogenesis of cardiac valves and septum

In lymphocytes, the expression of early immune response genes is regulated by NF-AT transcription factors which translocate to the nucleus after dephosphorylation by the Ca2+-dependent phosphatase, calcineurin. We report here that mice bearing a disruption in the NF-ATc gene fail to develop normal cardiac valves and septa and die of circulatory failure before day 14.5 of development. NF-ATc is first expressed in the heart at day 7.5, and is restricted to the endocardium, a specialized endothelium that gives rise to the valves and septum. Within the endocardium, specific inductive events appear to activate NF-ATc: it is localized to the nucleus only in endocardial cells that are adjacent to the interface with the cardiac jelly and myocardium, which are thought to give the inductive stimulus to the valve primordia. Treatment of wild-type embryos with FK506, a specific calcineurin inhibitor, prevents nuclear localization of NF-ATc. These data indicate that the Ca2+/calcineurin/NF-ATc signalling pathway is essential for normal cardiac valve and septum morphogenesis; hence, NF-ATc and its regulatory pathways are candidates for genetic defects underlying congenital human heart disease.