Reduced expression and impaired kinase activity of a Chk2 mutant identified in human lung cancer

The checkpoint kinase Chk2 is phosphorylated and activated in response to DNA damage such as ionizing radiation. Recently, we found a somatic mutation of CHK2 with clear loss of the wild-type allele in human lung cancer. Here we show that the mutant Chk2 exhibits modestly reduced in vitro kinase activity compared with wild type, whereas it is normally phosphorylated and activated after ionizing radiation. Interestingly, this mutant Chk2 protein was found to be less stable than wild type and could be expressed in various cell types only at a significantly reduced (20%) level of wild type. These findings confirm that the DNA damage checkpoint pathway involving CHK2 is indeed inactivated in this fatal adult cancer and also suggest that reduced expression of Chk2 may also be an important inactivating mechanism, contributing to the development of lung cancer.

Generation of definitive hematopoietic stem cells from murine early yolk sac and paraaortic splanchnopleures by aorta-gonad-mesonephros region-derived stromal cells

There is controversy as to whether murine definitive hematopoiesis originates from yolk sac (YS) or the intraembryonic region. This study reports the generation of definitive hematopoietic stem cells (HSCs) from both early YS and intraembryonic paraaortic splanchnopleures (P-Sp) on AGM-S3 stromal cells derived from the aorta-gonad-mesonephros (AGM) region at 10.5 days post coitum (dpc). YS and P-Sp cells at 8.5 dpc generated no definitive hematopoiesis-derived colony-forming cells in cocultures with AGM-S3 cells, but spleen colony-forming cells and HSCs capable of reconstituting definitive hematopoiesis in adult mice simultaneously appeared on day 4 of coculture. Precursors for definitive HSCs were present in YS and P-Sp at 8.0 dpc, a time when YS and embryo were not connected by blood vessels. It is proposed that precursors with the potential to generate definitive HSCs appear independently in YS and intraembryonic P-Sp and that the P-Sp or AGM region affords the microenvironment that facilitates generation of definitive hematopoiesis from precursors.

Temporary percutaneous aortic balloon occlusion to enhance fluid resuscitation prior to definitive embolization of posttraumatic liver hemorrhage

We successfully stabilized severe hemorrhagic shock following traumatic liver injury by percutaneous transcarotid supraceliac aortic occlusion with a 5 Fr balloon catheter. Then we were able to perform transfemoral embolization therapy of the hepatic arterial bleeding source. Transient aortic occlusion using a balloon catheter appears to be a useful adjunct in select cases where stabilization of the patient is necessary to allow successful selective embolization of the bleeding source.

Sleep patterns during 30-m nitrox simulated saturation dives

The sleep patterns were examined during the simulated 30-m nitrox saturation dives. The standard polysomnography of 15 divers was recorded for a total of 255 nights, as were patterns of change or consistency in sleep variables. A reduction of total sleep time in accordance with the lengthening of sleep latency and the wake after sleep onset was observed through the latter part of the bottom period to the post-dive period, but the other sleep variables did not show any changes. These findings suggest that decompression and the psychological stress due to being in the closed environment of a hyperbaric chamber for a long time have effects on divers' sleep.

Development of orally active nonpeptidic inhibitors of human neutrophil elastase

5-Amino-2-phenylpyrimidin-6-ones, some of their desamino derivatives, and miscellaneous derivatives were synthesized and biologically evaluated on both in vitro activity and oral activity in an acute hemorrhagic assay. These compounds contained an alpha-keto-1,3,4-oxadiazole moiety to bind covalently to the Ser-195 hydroxy group of human neutrophil elastase (HNE). Among those tested, compounds 11a-c,e,i-l(F), 11d,e,k(H), 21d,e,k(F), and 21d,e(H) showed a good oral profile. RS-Mixture 3(H) was selected for clinical evaluation based on its oral potency, duration of action, enzyme selectivity, safety profile, and ease of synthesis. Structure-activity relationships (SARs) are discussed.

Evidence for the presence of murine primitive megakaryocytopoiesis in the early yolk sac

During mouse embryogenesis, primitive erythropoiesis occurs in blood islands of the yolk sac (YS) on the seventh day of gestation. This study demonstrated for the first time the presence of unique primitive megakaryocytic (Mk) progenitors in the early YS, which disappeared by 13.5 days postcoitum (dpc). When 7.5 dpc YS cells were incubated in the presence of stem cell factor (SCF), interleukin (IL)-3, IL-6, erythropoietin (EPO), thrombopoietin (TPO), and granulocyte colony-stimulating factor in methylcellulose clonal culture, not only erythroid bursts but also megakaryocyte colonies were observed. The megakaryocytes in the colonies matured to proplatelet stages and produced platelets as early as day 3 of culture, much earlier than those from adult bone marrow, although their ploidy class was lower. These megakaryocytes were stained with acetylcholine esterase, and expressed platelet glycoprotein (GP)Ib beta, GPIIIa, and platelet factor 4 by reverse transcription-polymerase chain reaction analysis. The analysis of hemoglobin types in erythrocytes obtained from hematopoietic multilineage colonies containing the megakaryocytes indicated that the Mk progenitors originated from primitive hematopoiesis. The primitive Mk progenitors formed colonies in the absence of any cytokines in fetal bovine serum (FBS)-containing culture, and SCF, IL-3, EPO, and TPO significantly enhanced the Mk colony formation. In FBS-free culture, however, no colony formation was induced without these cytokines. Because megakaryocytes were detected in 8.5-dpc YS, these unique primitive Mk progenitors may rapidly mature and give rise to platelets to prevent hemorrhage in the simultaneously developing blood vessels until definitive hematopoiesis begins to produce platelets. (Blood. 2001;97:2016-2022)

The crystal structure of the complex of non-peptidic inhibitor of human neutrophil elastase ONO-6818 and porcine pancreatic elastase

The crystal structure of a new inhibitor of human neutrophil elastase (HNE), N-[2-[5-(tert-butyl)-1,3,4-oxadiazol-2-yl]-(IRS)-1-(methylethyl)-2-oxoethyl]-2-(5-amino-6-oxo-2-phenyl-6H-pyrimidin-1-ly)acetamide (ONO-6818, 1) complexed to porcine pancreatic elastase (PPE) has been determined at 1.86 A resolution. Analytical results provided evidence of a 1:1 complex in which the electrophilic ketone of 1 covalently bound to O gamma of Ser195 at the active site of PPE. The role of the unique electron-withdrawing ketone of 1 has been elucidated.

Intense immunosuppression followed by purified blood CD34+ cell autografting in a patient with refractory juvenile rheumatoid arthritis

A 15-year-old boy with refractory juvenile rheumatoid arthritis (JRA) underwent intense immunosuppressive therapy followed by purified blood CD34+ cell autografting. He had been taking prednisolone (PDN) daily or every other day combined with methotrexate once a week to control the disease for 7 years. He suffered from psychological complications and a very short stature due to the adverse effects of these drugs. CD34+ cells were purified in bulk from G-CSF-mobilized PBSC using an Isolex 300. After the administration of cyclophosphamide (200 mg/kg) and anti-lymphocyte globulin (45 mg/kg), 3.6 x 10(6)/kg purified CD34+ cells were infused. His post-transplant course was uneventful except for herpes-zoster infection. He is now more than 1 year post transplant and has not taken any immunosuppressive medication. His rate of growth has increased (>10 cm/year) due to the effects of the cessation of PDN and the administration of recombinant human growth hormone (rGH), in contrast to the gain of 2 cm in the preceding 3 years with rGH treatment. Although the durability of this remission is unknown, intense immunosuppressive therapy followed by purified blood CD34+ cell autografting might be acceptable for adolescent patients with refractory JRA to achieve a drug-free period for physical and psychological maturation.

Unusual early bile excretion from the liver in patients with fulminant hepatic failure as detected by Tc-99m-PMT hepatobiliary scintigraphy; Comparison with Tc-99m-GSA scintigraphy

In two females (58 and 14 years old) with fulminant hepatic failure, Tc-99m-PMT hepatobiliary scintigraphy was used to evaluate intrahepatic bile stagnation, and Tc-99m-GSA scintigraphy to evaluate hepatic functional reserve. In both patients, Tc-99m-PMT hepatobiliary scintigraphy showed unusual early bile excretion into the extrahepatic bile duct and small intestine within the first 30 min of imaging. These findings contradicted typical findings of intrahepatic bile stagnation of fulminant hepatic failure. The receptor index and blood clearance index determined from dynamic acquisition data on Tc-99m-GSA scintigraphy suggested a markedly decreased hepatic functional reserve. These findings were compatible with fulminant hepatic failure. A discrepancy was observed between the findings of hepatobiliary scintigraphy and those of Tc-99m-GSA scintigraphy. The pathological state of early bile excretion from the liver into the bile duct should be considered in fulminant hepatic failure.

[Estimation of daily dietary intake of aluminum]

The daily dietary intake of aluminum was estimated through a total diet study from 1996 to 1998. In ten institutes, total diet study samples were prepared and their aluminum concentration was determined. The average daily intake of aluminum was 3.5 mg and the range was 1.8-8.4 mg. The validity of the analytical result was supported by analyses of certified reference materials.

CD34 expression on long-term repopulating hematopoietic stem cells changes during developmental stages

The CD34 antigen serves as an important marker for primitive hematopoietic cells in therapeutic transplantation of hematopoietic stem cells (HSC) and gene therapy, but it has remained an open question as to whether or not most HSC express CD34. Using a competitive long-term reconstitution assay, the results of this study confirm developmental changes in CD34 expression on murine HSC. In fetuses and neonates, CD34 was expressed on Lin(-)c-Kit(+) long-term repopulating HSC of bone marrow (BM), liver, and spleen. However, CD34 expression on HSC decreased with aging, and in mice older than 10 weeks, HSC were most enriched in the Lin(-)c-Kit(+)CD34(-) marrow cell fraction. A second transplantation was performed from primary recipients who were transplanted with neonatal Lin(-)c-Kit(+) CD34(high) HSC marrow. Although donor-type HSC resided in CD34-expressing cell fraction in BM cells of the first recipients 4 weeks after the first transplantation, the stem cell activity had shifted to Lin(-)c-Kit(+)CD34(-) cells after 16 weeks, indicating that adult Lin(-)c-Kit(+)CD34(-) HSC are the progeny of neonatal CD34-expresssing HSC. Assays for colony-forming cells showed that hematopoietic progenitor cells, unlike HSC, continue to express CD34 throughout murine development. The present findings are important because the clinical application of HSC can be extended, in particular as related to CD34-enriched HSC and umbilical cord blood HSC.

Regulation kinetics of Na+-Ca2+ exchange current in guinea-pig ventricular myocytes

To investigate the regulation of native cardiac Na+-Ca2+ exchange by cytoplasmic Na+ (Na+i) and Ca2+ (Ca2+i), we recorded the Na+-Ca2+ exchange current (INa-Ca) from inside-out 'macro patches' excised from intact guinea-pig ventricular cells. The half-maximal concentration (Kh) of Ca2+i required to induce an inward INa-Ca was 7 microM. The Kh of Na+i required to induce an outward INa-Ca was 21 mM, and tended to decrease at the steady state of Na+-dependent inactivation. The time constant (tau) of Na+-dependent inactivation was approximately 1.5 s at 100 mM Na+i and 1 microM Ca2+i. The Kh for Na+i was 14 mM. Ca2+i augmented the peak outward INa-Ca (Kh = 0. 2 microM) and attenuated Na+-dependent inactivation (Kh = 2.2 microM). The outward INa-Ca was activated by 5 microM Ca2+i with a half-time to reach steady state (t1/2) of approximately 0.4 s. This activation was composed of two exponential processes. Deactivation of the current upon Ca2+i removal also consisted of two exponential processes and had a t1/2 of approximately 0.5 s. A Na+-Ca2+ exchange model, consisting of one consecutive 4Na+:1Ca2+ exchange cycle and two inactive states, well mimicked the experimental data with regard to ion dependencies and regulation kinetics. These data provide detailed information on the kinetics of the Na+i- and Ca2+i-dependent regulation of native Na+-Ca2+ exchange. They also indicate that the regulation kinetics operate faster in macro patches than in the giant membrane patch from cardiac 'blebs', or in Xenopus oocytes expressing a cloned exchanger (NCX1.1).

Direct intraoperative measurements of aortic and pulmonary blood flows in patients with severe pulmonary artery hypertension

BACKGROUND

Evaluate the significance of direct intraoperative measurements of aortic and pulmonary blood flows by electromagnetic flowmeter as an absolute decision basis for operability in patients with ventricular septal defect/complete atrioventricular septal defect and severe pulmonary artery hypertension.

METHODS

EXPERIMENTAL DESIGN

Prospective study.

SETTING

Institutional practice.

PATIENTS

Eight patients with marginal operability based on preoperative Doppler echocardiography and cardiac catheterization (pulmonary-to-systemic flow ratio=1.1-2.3, pulmonary-to-systemic resistance ratio=0.34-0.91, and pulmonary vascular resistance=4.6-18.2 units x m2) underwent direct intraoperative measurements of aortic and pulmonary blood flows by electromagnetic flowmeter. Operation would be performed according to the results of direct intraoperative measurements in every patient.

RESULTS

Aortic flow by direct intraoperative measurements ranged from 0.9 to 3.2 L/min/m2, and pulmonary blood flow from 4.1 to 8.4 L/min/m2. Pulmonary-to-aortic flow ratio was calculated at 2.1-6.6. Pulmonary vascular resistance ranged from 2.6 to 7.7 units x m2. We assessed that all patients still had operability, and performed corrective operations. Postoperative courses corresponded with the data from the direct intraoperative measurements.

CONCLUSIONS

When some clinical findings, particularly Doppler echocardiographic findings, of these patients are slightly in favor of reversibility of pulmonary vascular disease despite discrepant data of preoperative cardiac catheterization under a tight control of carbon dioxide tension, we recommend that direct intraoperative measurement of aortic and pulmonary blood flows is especially useful in decision making for the operability of patients with severe pulmonary artery hypertension.

Ataxia telangiectasia-mutated phosphorylates Chk2 in vivo and in vitro

The protein kinase Chk2, the mammalian homolog of the budding yeast Rad53 and fission yeast Cds1 checkpoint kinases, is phosphorylated and activated in response to DNA damage by ionizing radiation (IR), UV irradiation, and replication blocks by hydroxyurea (HU). Phosphorylation and activation of Chk2 are ataxia telangiectasia-mutated (ATM) dependent in response to IR, whereas Chk2 phosphorylation is ATM-independent when cells are exposed to UV or HU. Here we show that in vitro, ATM phosphorylates the Ser-Gln/Thr-Gln (SQ/TQ) cluster domain (SCD) on Chk2, which contains seven SQ/TQ motifs, and Thr68 is the major in vitro phosphorylation site by ATM. ATM- and Rad3-related also phosphorylates Thr68 in addition to Thr26 and Ser50, which are not phosphorylated to a significant extent by ATM in vitro. In vivo, Thr68 is phosphorylated in an ATM-dependent manner in response to IR, but not in response to UV or HU. Substitution of Thr68 with Ala reduced the extent of phosphorylation and activation of Chk2 in response to IR, and mutation of all seven SQ/TQ motifs blocked all phosphorylation and activation of Chk2 after IR. These results suggest that in vivo, Chk2 is directly phosphorylated by ATM in response to IR and that Chk2 is regulated by phosphorylation of the SCD.

Evaluation of arid region browse species from north eastern Nigeria using pen fed goats

Four 18-26 months old castrated Borno whitexSokoto Red goats were used in a 4x4 Latin square design to measure the dry matter intake (DMI), daily body weight change and dry matter digestibility (DMD) of four native Nigerian browse species, (Ziziphus spinochrist, Wild., Acacia albida, Del., Sterculia satigera, Guill. and Anogeissus licocarpus, Guill.) native to the semi-arid regions. The mean DMI of Z. spinochrist, Wild. and A. albida, Del. were similar but higher than for S. satigera, Guill. and A. licocarpus, Guill. The DMD of A. licocarpus,Guill. was lower (p<0.05) than for Z. spinochrist, Wild., Acacia licocarpus, Del. or S. satigera, Guill. The lowest body weight gain recorded was for A. licocarpus, Guill.; this was attributed to the larger amount of fibre in the forage resulting in a slow rate of cell wall degradation and rumen digestibility. Goats showed no visual signs of toxicosis. This study suggests that A. albida, Del. has the highest forage value for goats followed by Z. spinochrist, Wild., S. satigera, Guill. and A. licocarpus, Guill. Potentially the species examined can provide feed for goats as well as for other small ruminants during long dry periods when other feed is unavailable.

Absolute configuration of a ceramide with a novel branched-chain fatty acid isolated from the epiphytic dinoflagellate, Coolia monotis

The absolute configuration of the chiral center at the C15 position of a novel branched-chain fatty acid derived from a new ceramide isolated from the epiphytic dinoflagellate Coolia monotis was determined to be of R from by reversed-phase HPLC after cleavage to 12-methylpentadecanoic acid and subsequent conversion with the chiral fluorescent reagent, (1R,2R)-2-(2,3-anthracenedicarboximido)cyclohexanol.

[A 67-year-old man with progressive disturbance of gait]

We report a 67-year-old man with progressive disturbance of gait. He was well until the spring of 1993 (62 years of the age), when he noted an onset of unsteady gait. He also noted that he started to have a difficulty in playing tennis, in which he became unable to hit the ball with his racket. He also noted parkinsonian features such as bradykinesia and loss of hand dexterity. He was treated with levodopa, which did not improve his symptoms. His MRI revealed marked atrophy of the cerebellum and the pons. The criss-cross high signal lesion was seen in the center of the pons. The third ventricle was dilated. The putamen was unremarkable. His subsequent course was complicated by easy to fall, difficulty in swallowing with episodes of aspiration pneumonia. He also developed nocturnal apneustic episodes. He was admitted to our hospital on November 15, 1998, when he was 67 years of the age. He had low grade fever and low blood pressure (98/70). He was anemic but not icteric. Tumors were palpated in his jaw, anterior chest, and in the left arm. He was alert but unable to convey his desire because of dyspnea and tracheostomy. His gaze was slightly restricted in the horizontal direction and markedly so in the vertical direction. Motor functions were difficult to evaluate. His clinical course was complicated by atelectasis of the right lung and pleural effusion. He developed marked edema and oliguria. He developed sudden bradycardia and expired on December 26, 1998. He was discussed in a neurological CPC and the chief discussant arrived at the conclusion that the patient had multiple system atrophy. Majority of the audience agreed with this diagnosis. Post-mortem examination revealed a lung cancer in the right lung (undifferentiated adenocarcinoma) with metastases to the liver, kidneys, lymph nodes, pericardium, pleura, skin, bone marrow, and the brain. Neuropathologic examination revealed marked atrophy of the pons and the cerebellum. The putamen showed brownish discoloration and atrophic changes. The substantia nigra showed marked neuronal loss and gliosis. Oligodendrocytic inclusion bodies (alpha-synuclein positive) were seen in the putamen, globus pallidus, substantia nigra, pontine nucleus, cerebellar white matter, internal capsule, cerebral peduncle, and the spinal cord. These findings are consistent with the pathologic diagnosis of multiple system atrophy. What was interesting to us was the presence of neurofibrillary tangles in the substantia nigra, nucleus ruber, globus pallidus, and subthalamic nucleus. Tuft-shaped astrocytes were also seen. This patient appears to be a rare example of combination of MSA and PSP.

Chk1 is an essential kinase that is regulated by Atr and required for the G(2)/M DNA damage checkpoint

Chk1, an evolutionarily conserved protein kinase, has been implicated in cell cycle checkpoint control in lower eukaryotes. By gene disruption, we show that CHK1 deficiency results in a severe proliferation defect and death in embryonic stem (ES) cells, and peri-implantation embryonic lethality in mice. Through analysis of a conditional CHK1-deficient cell line, we demonstrate that ES cells lacking Chk1 have a defective G(2)/M DNA damage checkpoint in response to gamma-irradiation (IR). CHK1 heterozygosity modestly enhances the tumorigenesis phenotype of WNT-1 transgenic mice. We show that in human cells, Chk1 is phosphorylated on serine 345 (S345) in response to UV, IR, and hydroxyurea (HU). Overexpression of wild-type Atr enhances, whereas overexpression of the kinase-defective mutant Atr inhibits S345 phosphorylation of Chk1 induced by UV treatment. Taken together, these data indicate that Chk1 plays an essential role in the mammalian DNA damage checkpoint, embryonic development, and tumor suppression, and that Atr regulates Chk1.

Abnormal pulmonary accumulation of indium-111 chloride in pneumocystis carinii pneumonia as detected by bone marrow scintigraphy

PURPOSE

Unusual pulmonary uptake of In-111 chloride in a patient with Pneumocystis carinii pneumonia and autoimmune hepatitis is described.

METHOD

In-111 chloride bone marrow scintigraphy was performed to evaluate the bone marrow activity associated with pancytopenia in a 56-year-old woman with autoimmune hepatitis.

RESULTS

An In-111 chloride bone marrow scan showed increased pulmonary uptake predominantly in both upper lung fields. P. carinii pneumonia was seen to be developing as an immunocompromised complication after treatment for autoimmune hepatitis.

CONCLUSION

When In-111 chloride bone marrow scintigraphy shows increased uptake in the lungs of immunocompromised patients, a combined opportunistic inflammatory disease such as P. carinii pneumonia should be considered in the diagnosis.

Absent circadian variation of blood pressure in patients with anorexia nervosa

OBJECTIVE

To examine whether circadian rhythm of blood pressure (BP) is altered in patients with anorexia nervosa (AN), and if so, to determine whether it is reversible after refeeding.

STUDY DESIGN

Ambulatory BP monitoring was performed on 17 female inpatients with AN (mean age, 13.3 +/- 1.9 years) at the time of admission and serially during refeeding; 17 age-matched normal weight, normotensive female inpatients served as control subjects.

RESULTS

Patients with AN had lost an average of 23.4% +/- 11.5% of body weight before the illness. Weight after refeeding was 105.6% +/- 9. 2% of that before illness. Mean 24-hour systolic BP (SBP) (96.5 +/- 8.6 mm Hg) and diastolic BP (DBP) (53.4 +/- 5.8 mm Hg) were significantly lower in patients with AN compared with those of control subjects (SBP, 106.1 +/- 6.5 mm Hg; DBP, 60.2 +/- 5.8 mm Hg). Although awake SBP and DBP were also lower in patients with AN, asleep SBP and DBP were not statistically different from those of control subjects. Night/day BP ratio in the control group was 0.93 +/- 0.06 in systolic and 0.92 +/- 0.09 in diastolic. Those values were significantly elevated in patients with AN (systolic 1.00 +/- 0. 09 and diastolic 1.00 +/- 0.09). After refeeding, the ratio decreased to 0.88 +/- 0.09 and 0.90 +/- 0.08,respectively (both P <. 05 vs baseline).

CONCLUSIONS

In patients with AN, circadian variation of BP is absent. This reverts to normal after refeeding.

Risk-adapted pre-emptive therapy for cytomegalovirus disease in patients undergoing allogeneic bone marrow transplantation

We prospectively evaluated a risk-adapted pre-emptive treatment with ganciclovir for CMV diseases in patients undergoing allogeneic bone marrow transplantation (BMT). High-level CMV antigenemia (10 or more positive cells on two slides) or CMV antigenemia at any level in patients with grade II-IV acute graft-versus-host disease (aGVHD) were chosen as risk factors. We also retrospectively evaluated virus reactivation in plasma using quantitative real-time polymerase chain reaction (PCR). Fifty patients were evaluable. None of the 27 patients with or without grade I aGVHD developed high-level CMV antigenemia or CMV disease. Among the 23 patients with grade II-IV aGVHD, 12 patients (52%) developed CMV antigenemia and were treated pre-emptively, of whom two developed CMV gastroenteritis or retinitis in spite of therapy. Six of the remaining 11 patients developed CMV gastroenteritis before CMV antigenemia was detectable. All of the eight patients with CMV diseases were successfully treated with ganciclovir and no deaths directly related to CMV disease occurred. In four of the seven evaluable patients with CMV gastroenteritis, real-time PCR was able to detect virus reactivation earlier than CMV antigenemia. Although our risk-adapted pre-emptive therapy effectively reduced CMV-related mortality, further refinements of this approach, particularly in the prevention of CMV gastroenteritis, may be achieved by incorporating real-time PCR.

DNA damage-induced activation of p53 by the checkpoint kinase Chk2

Chk2 is a protein kinase that is activated in response to DNA damage and may regulate cell cycle arrest. We generated Chk2-deficient mouse cells by gene targeting. Chk2-/- embryonic stem cells failed to maintain gamma-irradiation-induced arrest in the G2 phase of the cell cycle. Chk2-/- thymocytes were resistant to DNA damage-induced apoptosis. Chk2-/- cells were defective for p53 stabilization and for induction of p53-dependent transcripts such as p21 in response to gamma irradiation. Reintroduction of the Chk2 gene restored p53-dependent transcription in response to gamma irradiation. Chk2 directly phosphorylated p53 on serine 20, which is known to interfere with Mdm2 binding. This provides a mechanism for increased stability of p53 by prevention of ubiquitination in response to DNA damage.

Stoichiometry of Na+-Ca2+ exchange in inside-out patches excised from guinea-pig ventricular myocytes

1. The stoichiometry (nx) of cardiac Na+-Ca2+ exchange was examined by measuring the reversal potential of the Na+-Ca2+ exchange current (INa-Ca) in large inside-out patches, 'macro patches', excised from intact guinea-pig ventricular cells. 2. Cytoplasmic application of Na+ (Na+i) or Ca2+ (Ca2+i) induced INa-Ca which showed properties similar to INa-Ca in the giant membrane patch. The outward INa-Ca was depressed by an exchanger inhibitory peptide, XIP. 3. The reversal potential of the XIP-sensitive current indicated that nx was approximately 4 (3.6-4.2) at 9-40 mM Na+i, and nx tended to increase as Na+i was increased. Proteolysis by trypsin did not significantly affect the stoichiometry. Similar results were obtained from the reversal potential of INa-Ca that was induced by application of both Na+i and Ca2+i. 4. At 0.1 microM Ca2+i, nx was approximately 4 (3.7-4. 4) at 6-25 mM Na+i and tended to increase as Na+i was increased. When Ca2+i was changed from 0.1 to 1 and 1000 microM at constant 50 mM Na+i, the value was approximately 4 (3.6-4.4). 5. When the extracellular Na+ (Na+o) and Ca2+ (Ca2+o) concentrations were varied in the presence of 25 or 9 mM Na+i and 1 microM Ca2+i, nx was almost constant ( approximately 4) over the range 0.3-20 mM Ca2+o and 10-145 mM Na+o. 6. These results indicated that the stoichiometry of Na+-Ca2+ exchange is different from generally accepted 3Na+:1Ca2+, and suggested that the stoichiometry is either 4Na+:1Ca2+ or variable depending on Na+i and Ca2+i.

[A case of HIV encephalopathy with dementia which showed significant improvement after the combination antiretroviral therapy]

We report a 63-year-old male with HIV encephalopathy, whose initial symptom was acutely progressing dementia. He tested positive for HIV antibody, and HIV-RNA count was 2.8 x 10(5) copy/ml. All opportunistic infections that could cause dementia were ruled out. Dementia remarkably improved after the combination antiretroviral therapy of three types of drugs, two being nucleoside analog reverse transcriptase inhibitors and one being a protease inhibitor. The combination therapy could be very effective for the treatment of HIV dementia.

Prediction of the development of hepato-cellular-carcinoma in patients with liver cirrhosis by the serial determinations of serum alpha-L-fucosidase activity

OBJECTIVE

Evaluation of the usefulness of the serial determinations of serum alpha-L-fucosidase (AFU) activity for prediction of the development of hepatocellular carcinoma (HCC) was performed.

METHODS AND PATIENTS

Serum AFU activity was determined monthly for 42 months in 73 patients with liver cirrhosis (LC).

RESULTS

HCC was diagnosed in 27 patients by means of ultrasonography during this observation period. In 23 (85%) of the 27 patients, serum AFU activity was found to exceed 700 nmole/ml/h during the LC stage. HCC developed within a few years in 23 (82%) of 28 LC patients with AFU activity exceeding 700 nmole/ml/h, in contrast, it developed in only 4 (9%) of 45 LC patients with AFU activity below 700 nmole/ml/h. AFU activity was already elevated in 23 (85%) of 27 patients at least 6 months before the detection of HCC by ultrasonography.

CONCLUSION

It is conceivable that the development of HCC can be predicted by means of serial determinations of serum AFU activity in patients with LC.

Plasma concentrations of atrial and brain natriuretic peptides and cyclic guanosine monophosphate in response to dobutamine infusion in patients with surgically repaired tetralogy of fallot

We examined the plasma concentrations of atrial and brain natriuretic peptides (ANP and BNP) and cyclic guanosine monophosphate (cGMP) during dobutamine infusion and their relationship with hemodynamic parameters in 14 patients with surgically repaired tetralogy of Fallot (TOF). Dobutamine was infused at an initial dose of 5 microgram/kg/min and increased by 5 microgram/kg/min up to 20 microgram/kg/min. The plasma ANP, BNP, and cGMP concentrations were determined before infusion, at the end of each stage, and 15 minutes after discontinuing dobutamine infusion. The plasma concentrations of ANP, BNP, and cGMP were elevated in all patients before dobutamine infusion. The ANP, BNP, and cGMP concentrations decreased in 11 of the 14 patients during dobutamine infusion. In contrast, the plasma ANP and BNP concentrations increased in the remaining 3 patients without a change in the cGMP concentration. The right ventricular pressure and volume were significantly elevated in these patients. The plasma cGMP concentration correlated with the ANP concentration (r = 0.62, p < 0.01) but not the BNP concentration. The plasma ANP concentration during dobutamine infusion correlated with right ventricular systolic pressure (r = 0.71, p < 0.05), mean right atrial pressure (r = 0.29, p < 0.05), and mean pulmonary capillary wedge pressure (r = 0.32, p < 0.05). The BNP concentration correlated with right ventricular volume (r = 0.61, p < 0.05) and systolic pressure (r = 0. 46, p < 0.05). In conclusion, rapid changes in ANP, BNP, and cGMP concentrations during dobutamine infusion reflect the changes in atrial and ventricle pressure and volume overload. In surgically repaired TOF, the ANP concentration is affected by right ventricular systolic pressure, right atrial pressure, and pulmonary capillary pressure. Furthermore, the BNP concentration reflects right ventricular pressure and volume overload.

Protective effects of bacteriophage on experimental Lactococcus garvieae infection in yellowtail

The present study describes the in vitro and in vivo survival of Lactococcus garvieae bacteriophages and the potential of the phage for controlling experimental L. garvieae infection in yellowtail. Anti-L. garvieae phages persisted well in various physicochemical (water temperature, salinity, pH) and biological (feed, serum and alimentary tract extracts of yellowtail) conditions, except for low acidity. In the in vivo, the phage PLgY-16 was detected in the spleens of yellowtail until 24 h after intraperitoneal (i.p.) injection, or the phage was recovered from the intestine of yellowtail 3 h after the oral administration of phage-impregnated feed but undetectable 10 h later. Simultaneous administration of live L. garvieae and phage enhanced recovery of the phage from the spleen or intestine. The survival rate was much higher in yellowtail that received i.p. injection of the phage after i.p. challenge with L. garvieae, compared with that of control fish without phage injection. When fish were i.p. injected with phage at different hours after L. garvieae challenge, higher protective effects were demonstrated in fish that received phage treatment at the earlier time. Protection was also obtained in yellowtail receiving phage-impregnated feed, in which fish were challenged by an anal intubation with L. garvieae. Anal-intubated L. garvieae were detected constantly in the spleens of the control fish, while they were detected sporadically and disappeared from the phage-treated fish 48 h later. On the other hand, orally administered phage was detected at high plaque-forming units from the intestines and spleens of the phage-treated fish until 48 h later. These results indicate that intraperitoneally or orally administered anti-L. garvieae phage prevented fish from experimental L. garvieae infection, suggesting potential use of the phage for controlling the disease.

Spontaneous regression of hepatocellular carcinoma

A 62-year-old Japanese man with hepatitis B virus-related liver cirrhosis revealed alpha-fetoprotein (AFP) elevation. Dynamic computed tomography, taken at this time, showed a liver tumor in the anterior segment. As the patient refused any further medical treatment, he was observed in an outpatient clinic. The size of the tumor reduced and the serum level of AFP decreased gradually without any treatment. Twelve months after the initial diagnosis, the tumor could not be detected by computed tomography (CT) scan, and the level of AFP had declined to the normal range. Blood supply is essential for tumor growth and an arterioportal shunt near the tumor may change the dynamics of blood flow to the tumor. The shunt found in this patient was thought to be one of the causative factors leading to regression, but it could not be denied that immunological mechanisms may have played an important role in the spontaneous regression of hepatocellular carcinoma.

Diurnal variations of blood pressure in dogs

Using the telemetry system, we measured the blood pressure (BP) invasively in seven adult mongrels while unanesthetized and unbound. Post-operative BP after implanting the telemetry BP transmitter showed temporarily high values due to the invasive nature of the surgery. It was, however, observed that BP gradually decreased thereafter, and showed settled trends from the eighth day post-operatively. When we took the average of the systolic, mean and diastolic BP at hourly intervals for each of the dogs once their BP had settled, a twin peak diurnal variation (at 8:00 and 19:00) was observed. Moreover, significantly high values (p < 0.05) were identified in active state compared with when sleeping or at rest. The 24 hr BP measured by the telemetry system in seven normal dogs resulted in the following values: systolic 123.4 +/- 7.9 mmHg, mean 91.1 +/- 5.6 mmHg, and diastolic 74.5 +/- 4.9 mmHg.

[Time-resolved three-dimensional contrast-enhanced MR angiography of the carotid artery]

Contrast-enhanced MR angiography (ceMRA) allows practical carotid arteriography without venous enhancement. However, it requires some intricate preparation such as a test bolus of the contrast agent or determination of the tracking volume even in the automatic triggering Smartprep system. The purpose of this study was to obtain carotid ceMRA without any preparation by means of a repeated multiple ultrashort three-dimensional MRA sequence (e3d56), i.e., time-resolved MRA (trMRA). Twenty-three patients underwent sagittal trMRA using a 1.0-Tesla superconducting unit. Multiple projection angiograms are acquired in three contiguous phases with a time resolution of 6 seconds per slab, including 10 partitions, after a bolus injection of 10 ml of Gd-DTPA followed by 20 ml of saline at 2 ml/sec. In all patients, the signal from the arteries could be separated from that of the veins in at least one phase. Carotid trMRA with 6-sec temporal resolution is a reliable technique for selective arteriography, avoiding the necessity of timing the contrast agent bolus.

Sleep patterns during 20-m nitrox saturation dives

The sleep patterns were examined through three simulated 20-m nitrox saturation dives. The standard polysomnography of 12 divers was recorded respectively for a total of 204 nights, as were patterns of change or consistency in sleep variables. For the 11 divers in their 20s and 30s there was nothing unusual about their sleep variables. However, a reduction of total sleep time in accordance with the lengthening of sleep latency was observed. This was recognized from the latter part of the bottom period to the postdive period. This tendency was notable for the diver in his 50s. These findings suggest that the decompression environment and the psychological stress of the long-term closed environment of a hyperbaric chamber have effects on divers' sleep.

Surgical management of infants with mitral valve stenosis or atresia without diminutive ascending aorta

The surgical strategy in infants with mitral valve stenosis or atresia without diminutive ascending aorta remains to be established, including the potential for biventricular repair as a definitive operation. Our surgical experience of six infants with mitral valve stenosis (4 patients) or atresia (2 patients) without diminutive ascending aorta was evaluated based on three important factors: left ventricular volume; the nature of the systemic outflow obstruction; and the type of mitral valve anomaly. Two patients with systemic outflow tract diameter less than 65% of normal underwent systemic outflow tract reconstruction, and the other patients with outflow tract diameter more than 68% of normal were able to maintain systemic circulation without repair. Only one patient with mitral valve stenosis without left ventricular outflow tract obstruction underwent a successful open mitral valvotomy as a biventricular repair after first-stage palliation. The left ventricle of the other patients did not grow after first-stage palliation. Due to progressive subaortic narrowing, pulmonary artery banding should be avoided in patients with mitral atresia due to absent atrioventricular connection who are future Fontan candidates. Most patients with this lesion can be expected to become candidates for safe Fontan-type repair.

Prevalence of specific allergic diseases in school children as related to parental atopy

BACKGROUND

Our objective was to investigate the influence of parental allergy on the manifestations and course of allergic disease in children.

METHODS AND RESULTS

A total of 15,234 school children aged 6 and 9 years were evaluated by means of questionnaires completed by their parents in a cross-sectional survey conducted in Tokushima, Japan. The prevalence and relative risk ratio (RRR) for parental allergy in children with atopic dermatitis, asthma and allergic rhinitis were 6.4% (RRR 2.5), 3.2% (RRR 2.4) and 15% (RRR 2.4), respectively. The risk of atopic dermatitis was particularly high in children whose parent had atopic dermatitis, with an RRR of 2.8 (father) and 3.7 (mother). Children with a parental history of asthma also had a high risk of that disorder (RRR of father 5.3, mother 6.2). However, the risk of allergic rhinitis was no different in children with a parental history of allergic rhinitis or from children with a parental history of asthma and atopic dermatitis. A history of allergic disease in both parents, especially of asthma and atopic dermatitis, increased the risk of allergic disease in the child. Milder symptoms, such as wheezy bronchitis, in schoolchildren were similarly related with the same hereditary tendency as the identical allergic disease. The disappearance of allergic symptoms with age also related to a hereditary component, being less likely in children with a history of parental allergy than in those without such an atopic history.

CONCLUSIONS

The manifestations and course of allergic disease in school children relate to parental allergic disease.

[Clinical effects of combination therapy with cefozopran and tobramycin for severe infections in patients with hematologic diseases]

We studied clinical effect of a combination therapy with cefozopran (CZOP) and tobramycin (TOB) for infections in 80 patients with hematologic diseases in 15 institutes. Combined doses with CZOP 2 g and TOB 60-90 mg twice a day had been given intravenously. Of the 80 patients, 61 patients (42 with acute leukemia, 10 with malignant lymphoma, 3 with aplastic anemia, 2 with chronic myeloid leukemia, 2 with multiple myeloma, and 2 with myelodysplastic syndrome) were evaluable. Those consisted of 6 patients with septicemia, 49 with suspected septicemia, 3 with pneumonia, and 3 with other infections. Clinical efficacy by the treatment was excellent in 24, good in 17, fair in 9, and poor in 11 patients, and the overall efficacy rate including excellent and good was 67.2%. Microbiologically, 5 of the 6 patients with septicemia (1 coagulase negative Staphylococcus, 2 S. pneumoniae, 1 S. oralis, and 1 E. coli) were responded. The efficacy rate in patients with severe granulocytopenia showing 100/microliter or lesser neutrophil counts during the drug administration was 57.1% (12/21). Side effects and abnormal changes of clinical laboratory findings were observed in 5 patients, and 16 patients, respectively, but most of them were mild. The findings above suggested that the combination therapy with CZOP and TOB is useful as an empiric therapy for severe infections in patients with hematologic diseases.

4F2 (CD98) heavy chain is associated covalently with an amino acid transporter and controls intracellular trafficking and membrane topology of 4F2 heterodimer

4F2, also termed CD98, is an integral membrane protein consisting of a heavy chain linked to a light chain by disulfide bond. We have generated a monoclonal antibody to the mouse 4F2 light chain and cloned the cDNA. It encodes a mouse counterpart of rat L-type amino acid transporter-1, and induces system L amino acid transport in Xenopus oocytes in the presence of 4F2 heavy chain. Transfection studies in mammalian cells have indicated that the 4F2 heavy chain is expressed on the plasma membrane on its own, whereas the 4F2 light chain can be transported to the surface only in the presence of 4F2 heavy chain. 4F2 heavy chain is expressed diffusely on the surface of fibroblastic L cells, whereas it is localized selectively to the cell-cell adhesion sites in L cells expressing cadherins. These results indicate that the 4F2 heavy chain is associated covalently with an amino acid transporter and controls the cell surface expression as well as the membrane topology of the 4F2 heterodimer. Although 4F2 heavy and light chains are expressed coordinately in most tissues, the light chain is barely detected by the antibody in kidney and intestine, despite the presence of heavy chain in a complex form. The results predict the presence of multiple 4F2 light chains.

White coat hypertension in two adolescents

We describe two adolescent boys with white coat hypertension. Both patients had significantly high blood pressure documented on more than three occasions at clinic. No cause for hypertension or target organ damage was demonstrated. Twenty-four-hour mean ambulatory blood pressure values were normal for height and sex, which led to the diagnosis.

Linkage of ATM to cell cycle regulation by the Chk2 protein kinase

In response to DNA damage and replication blocks, cells prevent cell cycle progression through the control of critical cell cycle regulators. We identified Chk2, the mammalian homolog of the Saccharomyces cerevisiae Rad53 and Schizosaccharomyces pombe Cds1 protein kinases required for the DNA damage and replication checkpoints. Chk2 was rapidly phosphorylated and activated in response to replication blocks and DNA damage; the response to DNA damage occurred in an ataxia telangiectasia mutated (ATM)-dependent manner. In vitro, Chk2 phosphorylated Cdc25C on serine-216, a site known to be involved in negative regulation of Cdc25C. This is the same site phosphorylated by the protein kinase Chk1, which suggests that, in response to DNA damage and DNA replicational stress, Chk1 and Chk2 may phosphorylate Cdc25C to prevent entry into mitosis.

[Effect of the skull on brain perfusion SPECT imaging]

Because attenuation gradually decreases reconstructed counts from the periphery to the center portion of the object, the deep region far from the detector is not clearly observed if attenuation is not compensated. In brain perfusion SPECT, diagnosis is sometimes made using filtered back projection images without attenuation compensation (FBP). Brain perfusion SPECT has the unique characteristic that the radiopharmaceutical accumulates only within the brain and is never taken up by the surrounding skull. This study investigated the effect of skull on brain perfusion SPECT reconstructed with FBP. We theoretically derived the relation between the counts of brain and the linear attenuation coefficient of skull. It was found that the difference in reconstructed counts between the deep gray matter and peripheral gray matter decreased due to the existence of the skull. This result indicated that the deep gray matter was inclined to be visible if the FBP images were displayed according to relative counts normalized to the maximum count of each image. In order to confirm this, we made a numerical phantom with realistic human brain and skull contours on the basis of MR images from a normal volunteer. The linear attenuation coefficient of brain was assumed to be 0.15 cm-1, while that of skull was assumed to be 0.26 cm-1 (denoted as BONE+) or 0 cm-1 (BONE-). In accordance with the theoretical results, the deep gray matter of BONE+ images was more clearly observed than that of BONE- images, if these were displayed using the relative counts of each images. The physical phantom experiments also supported the theoretical and numerical phantom studies.

Usefulness of color kinesis imaging for evaluation of regional right ventricular wall motion in patients with surgically repaired tetralogy of Fallot

We evaluated regional right ventricular wall motion during systole in patients with surgically repaired tetralogy of Fallot (TOF) using color kinesis imaging. Color kinesis images were obtained in a subcostal sagittal view from 19 patients with repaired TOF (TOF group), aged 3 to 5 years, and 20 age-matched normal subjects (control group). For regional wall motion analysis, the endocardial motion distance and the fractional area change (FAC) were calculated for 6 segments obtained from color kinesis images. The endocardial inward excursion distances and the FACs in the upper, middle, and lower posterior segments of the TOF group were significantly greater than those of the control group (p <0.01 for each segment). The upper anterior segment showed significantly reduced inward excursion distance and FAC in the TOF group than in the control group (p <0.01, both). The dyskinetic outward excursion distances of the middle and lower posterior segments were significantly lower in the TOF group than in the control group (p <0.01, both). In the upper and middle anterior segments, the endocardial outward excursion distances were significantly higher in the TOF group than in the control group (p <0.01 and 0.05). Correlation between right ventriculographic and color kinesis measurements was excellent (y = 1.14x - 1.30, r = 0.87 for the endocardial inward excursion, and y = 1.03x +/- 0.56, r = 0.91 for the FAC). In conclusion, color kinesis is a useful method for assessing regional right ventricular wall motion. Segmental analysis of color kinesis images provides accurate, automated, and quantitative diagnosis of regional right ventricular wall motion abnormalities in patients with surgically repaired TOF.