Involvement of p38 MAPK signaling pathway in IFN-γ and HTLV-I expression in patients with HTLV-I-associated myelopathy/tropical spastic paraparesis

We analyzed the relationship between the expression of interferon (IFN)-gamma and HTLV-I p19 antigen and activation of p38 mitogen-activated protein kinase (p38 MAPK) in two HTLV-I-infected T cell lines derived from two patients (HCT-1 and HCT-4) with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), and three HTLV-I-infected T cell lines derived from three patients with adult T cell leukemia (ATL). Expression of phosphorylated (activated)-p38 MAPK was markedly increased concomitant with high levels of both IFN-gamma and HTLV-I p19 antigen expression in both HCT-1 and HCT-4 compared with cell lines derived from ATL patients. Treatment with SB203580, a specific inhibitor of p38 MAPK, suppressed IFN-gamma and HTLV-I p19 antigen expression levels in HCT-1, HCT-4 and peripheral blood CD4(+) T cells of HAM/TSP patients. These findings strongly suggest that activation of p38 MAPK signaling pathway is involved in the up-regulation of IFN-gamma expression with high HTLV-I proviral load in HAM/TSP patients.

Prognostic value of age and sex in early gastric cancer

BACKGROUND

The need for lymph node dissection in early gastric cancer (EGC) is controversial. The present study investigated the possibility of planning treatment for EGC according to age and sex rather than node status.

METHODS

Overall survival rate and cause of death were analysed according to age (5-year increments) and sex in 4231 patients with EGC. Cox proportional hazard regression analyses were used to identify the most valuable predictor.

RESULTS

In patients with EGC 5- and 10-year cancer-specific survival rates were 98.4 and 96.3 per cent respectively, whereas corresponding overall survival rates were 90.2 and 80.9 per cent. The critical age for determining prognosis was 70 years for men (chi2 = 131.34, P < 0.001) and 75 years for women (chi2 = 64.35, P < 0.001). For both sexes, the 10-year overall survival rate was less than 30 per cent in patients over 80 years old. Multivariate Cox stepwise regression analysis identified age as the most powerful prognostic indicator in EGC. The rate of death from causes unrelated to the tumour increased significantly with age, whereas that from recurrence was not affected by age.

CONCLUSION

Age is a better prognostic indicator than node status in both men and women with EGC. Age and sex should be taken into account as well as conventional clinicopathological variables related to lymph node metastases when determining appropriate therapy for EGC.

Effects of bilateral resection of facial nerves on suckling in developing rats

The purpose of the present study is to investigate functional role of the facial nerve on suckling in developing rats. The bilateral resection of facial nerves on postnatal day 1 (P1) resulted in cell loss of facial motoneurons and complete facial paralysis without any whisker movement or nictitating reflex at the end of the postnatal 3 weeks. Although the body weight of the nerve-resected rats increased gradually for the postnatal 3 weeks, they weighed less than the control rats without nerve resection. The nerve-resected rats contained less milk (0.25 +/- 0.02 g) than the control rats (0.35 +/- 0.02 g) in the stomach on P17. On P21, the body weight of the nerve-resected rats (25.33 +/- 0.32 g) was decreased by 28% compared to that of the control rats (35.08 +/- 0.57 g). Although their growth was substantially more retarded than that of the control animals, most (92%) of the nerve-resected pups could survive without facial nerve innervation. The orofacial musculature innervated by the facial nerve plays an important role in breastfeeding, but the present study shows that these muscles are not essential for the survival of neonatal rats.

Neurotrophic effect of hepatocyte growth factor on neonatal facial motor neurons

The neurotrophic effect of hepatocyte growth factor (HGF) on axotomized facial motor neurons was examined after local application of HGF to the proximal facial nerve stump of the neonatal rat on post-natal day one (P1). Motor neuron survival was expressed as the neuronal cell count on the injured side as a percentage of that on the noninjured side. Motor neuron survival of the control group was 76% on P3, 54% on P5 and 23% on P8, that of the HGF-treated group 78% on P3, 69% on P5 and 31% on P8, and that of the brain-derived neurotrophic factor (BDNF)-treated group 91% on P5 and 45% on P8. The motor neuron survival rates were then adjusted by deducting the facial motor neurons corresponding to the uninjured retroauricular branch (20%) of the facial nerve. The adjusted values were 70% (P3), 42% (P5) and 4% (P8) for the control group, 72% (P3), 61% (P5) and 14% (P8) for the HGF-treated group, and 88% (P5) and 32% (P8) for the BDNF-treated group. These findings demonstrate that HGF has a neuroprotective effect on injured facial motor neurons and suggest that HGF has neurotrophic properties distinct from those of BDNF.

Aberrant methylation of suppressor of cytokine signalling-1 (SOCS-1) gene in pancreatic ductal neoplasms

The suppressor of cytokine signalling-1 (SOCS-1) gene is frequently silenced in human hepatocellular carcinoma by aberrant methylation. The aim of this study was to determine if SOCS-1 is inactivated in pancreatic ductal neoplasms, and to investigate if aberrant methylation of this gene affected the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway. Aberrant methylation in the CpG island of the SOCS-1 gene was detected in six of 19 (31.6%) human pancreatic cancer cell lines using methylation-specific PCR, and was associated with a loss or reduction of gene expression in five of the six methylated cell lines. Thirteen of 60 pancreatic ductal adenocarcinomas (21.7%) and two of 34 intraductal papillary mucinous neoplasms (IPMNs) (5.9%) had methylated SOCS-1. In contrast, SOCS-1 methylation was not seen in pancreatic normal ductal epithelia (zero out of 15), in pancreatic intraepithelial neoplasia (PanINs) (zero out of 49) or in the IPMNs without infiltrating cancer (zero out of 20). 5-Aza-2'-deoxycytidine treatment of the SOCS-1-methylated pancreatic cancer cell lines led to restoration of SOCS-1 gene expression. Interleukin-6, which has been shown to act through the JAK/STAT pathway to increase cell growth, induced modest time and dose-dependent cell proliferation in a SOCS-1-methylated cell line (PL10, P=0.015) but not in two unmethylated cell lines. These results indicate that loss of SOCS-1 gene is associated with transcriptional silencing and may have growth-promoting effects, and that its methylation is a useful marker of pancreatic cancer.

Regenerative process of the facial nerve: rate of regeneration of fibers and their bifurcations

After the main trunk of the mouse facial nerve was injured by crushing, a fiber tracing method was used to quantify the facial motor neurons that extended regenerating nerve fibers to the specific site of the facial nerve branch. The total number of motor neurons retrogradely labeled with a fluorescent tracer, Fluoro-Gold (FG), were 0 on postsurgical days (PSDs) 1 and 2, 75+/-25 on PSD3, 264+/-21 on PSD4, 378+/-19 on PSD6, 428+/-19 on PSD8, 491+/-13 on PSD12 and 532+/-15 on PSD16. Assuming that the FG-positive neurons (535+/-11) of the control mice represent 100%, the FG-labeled neurons accounted for 0, 14, 49, 71, 80, 92 and 99% on the corresponding days. Two different fluorescent tracers were applied to the different facial nerve branches 16 days after facial nerve injuries. Double-labeled neurons were consistently found in the nerve-crushed facial nucleus (3.2%), and their number increased in the nerve-transected facial nucleus (12.2%). The present study indicates that the regenerating facial nerve consists of heterogeneous nerve fibers with varying growth rates and that excessive axonal branching occurs more frequently in the nerve-transected than in the nerve-crushed injuries.

Proliferating cell populations in experimentally-induced hydrocephalus in developing rats

To examine the fate of proliferating brain cells in hydrocephalus (Hydro), experimental Hydro was induced in neonatal rats by intracisternal injection of kaolin and, 3 weeks later, the rats were injected with bromodeoxyuridine (BrdU). The BrdU (+) cells were immunohistochemically analyzed by using antibodies against neural (nestin), neuronal (NeuN) and glial (GFAP and MBP) markers in the posterior cerebrum. The percentage of nestin expression for the BrdU (+) cells was 8% in control and increased from 17% in the Hydro to 33% in the Hydro at an earlier stage after the shunt procedure, but was restored to 6% in the Hydro at a later stage after the shunt procedure. The percentages of GFAP expression showed a similar tendency to those of nestin expression. The BrdU (+) cells did not express either NeuN or MBP throughout the experiments.

Great potentiality of neonatal facial motor neurons for neural plasticity as determined by functionally essential neuronal population

The present study was undertaken to determine the neuronal population essential for normal and minimal facial function of young adult rats that had received various degrees of crush injuries to the facial nerve in the neonatal period. Using a neuronal tracer, it was found in young adult rats receiving neonatal injuries that the minimum number of tracer-labeled facial motor neurons necessary for normal facial function corresponded to 13-14% of the neurons (2540+/-64) of the age-matched control animals, whereas the minimum number of neurons necessary for minimal facial function corresponded to 5%. On the other hand, the minimum numbers of tracer-labeled facial motor neurons necessary for normal and minimal facial function of young adult rats that received various degrees of crush injuries corresponded to 61 and 27-30%, respectively, of the neurons (2540+/-64) of the uninjured control animals. These results indicate that the facial function of animals with nerves crushed at the neonatal stage can be adequately maintained by a very small population of neurons, implying a great potential of neonatal neurons for neural plasticity.

[Fontan operation; progress in the methodology and its outcome]

In recent years, the outcome of the Fontan-type operation has markedly improved by the application of total cavopulmonary connection method, the staged strategy to reach Fontan operation and the application of fenestration. In this report, the histological aspect of the changes in the operative techniques and the long term outcome in our institution are described.

Functionally essential neuronal population of the facial motor nucleus

Cranial nerve impairment is one of the more serious complications in neurosurgery. Nevertheless, the important question of how many neurons are required for cranial nerve functions remains unanswered. The VIIth cranial nerve (facial nerve) in mice was subjected to graded crush injuries. After assessment of the facial function, the number of uninjured, healthy facial motor neurons was quantified with a retrograde neuronal tracer. We report that normal facial function is preserved if intact neurons account for more than 56% of the control value, while complete facial paralysis occurs if intact neurons are reduced to less than 32% of the control value.

Differential neurogenesis and gliogenesis by local and migrating neural stem cells in the olfactory bulb

The rostral migratory stream (RMS) is a unique forebrain structure that provides a long-distance migratory route for the neural stem cells of the periventricular region towards the olfactory bulb (OB). The purpose of the study presented here is to examine the extent of neurogenesis and gliogenesis by the neural stem cells of different origins (periventricular vs. intrabulbar) in the OB. After the RMS had been subjected to injury, the rats received intraperitoneal injections of 5-bromodeoxyuridine (BrdU) and were further reared for 2 weeks. Neuronal and glial differentiations of the BrdU(+) cells in the olfactory bulbar granule cell (OB-GCL) and the olfactory glomerular (OB-GL) layers were examined immunohistochemically using antibodies against neuronal (NeuN, neuronal nuclei) and glial (GFAP, glial fibrillary acidic protein) markers in the OBs with injured and uninjured (control) RMS. In the completely RMS-lesioned OB, where migration of the periventricular neural stem cells was inhibited, a small number of BrdU(+) NeuN(+) cells were found in both the OB-GCL and OB-GL. The BrdU(+) NeuN(+) cells accounted for a much higher percentage of the BrdU(+) cells on the control side (OB-GCL, 36.7%; OB-GL, 8.8%) than on the completely RMS-lesioned side (OB-GCL, 3.7%; OB-GL, 0.6%). The percentage of the BrdU(+) GFAP(+) cells relative to the BrdU(+) cells did not show any major difference between the control and completely RMS-lesioned sides. This study revealed differences in neurogenesis and gliogenesis between the local and migrating neural stem cells in the OB of the adult rodent.

Implications of peritoneal washing cytology in patients with potentially resectable pancreatic cancer

BACKGROUND

The aim of this study was to assess the implications of positive peritoneal washing cytology for management of patients with potentially resectable pancreatic cancer.

METHODS

Cytological examination of peritoneal washings was performed in 134 patients who underwent surgical resection for pancreatic adenocarcinoma. The clinicopathological findings and the relationship between cytology results (including cytomorphology) and survival were investigated.

RESULTS

One hundred and fourteen patients (85 per cent) had negative cytology results (group 1). Excluding one patient with atypical cells, positive cytology results were obtained in 19 patients (14 per cent): 16 patients without macroscopic peritoneal metastases (group 2) and three patients with minimal macroscopic peritoneal metastases (group 3). The patients in group 2 had significantly larger (P < 0.001) and more advanced (P = 0.022) tumours than those in group 1. However, there were no significant differences in postoperative cumulative survival rates between groups 1 and 2 (P = 0.347). Two patients in group 2 are long-term survivors (40 and 58 months). In cytomorphological analyses, the presence of clusters with ragged edges and isolated carcinoma cells can be considered to indicate a high risk of peritoneal recurrence.

CONCLUSION

Positive cytology does not directly predict peritoneal carcinomatosis and, while associated with advanced disease, does not contraindicate radical surgery.

Cell dynamics of calretinin-immunoreactive neurons in the rostral migratory stream after ibotenate-induced lesions in the forebrain

It is now apparent that adult neurogenesis is taking place during life in the olfactory bulb (OB) of the rodent brain. In the olfactory nervous system, the precursor cells of the subventricular zone are known to continually proliferate, migrate through the rostral migratory stream (RMS) and differentiate into the bulbar neurons. The RMS, consisting of heterogeneous cell populations of the neural and neuronal precursor cells, is the unique forebrain structure that provides a long-distance migratory route for the precursor cells. The present study was undertaken to examine whether neuronal regeneration, focusing on calretinin-immunoreactive (+) cells, may proceed in the RMS following lesions induced by an excitotoxin. Two days after ibotenate injections, massive degeneration of calretinin (+) cells occurred in the RMS and its adjacent forebrains. Thereafter, calretinin (+) cells gradually increased in the RMS and reached above their control value 2 weeks after ibotenate injections. Removal of the OB also produced a marked increase in calretinin (+) cells in the RMS. Autoradiographic experiments using (3)H-thymidine showed that calretinin (+) cells were continually generated in the RMS and underwent neuronal turnover within 8 weeks in a normal condition. The results indicate that, in terms of calretinin (+) cells, neuronal differentiation and replacement is continually taking place within the RMS, and that the RMS is capable of repopulating those cells which were injured by ibotenate.

The minimum number of neurons in the central olfactory pathway in relation to its function: a retrograde fiber tracing study

The present study was aimed at determining the functionally essential size of the neuronal population in the central olfactory nervous system. Using conditioned rats who had learnt to avoid repellent (cycloheximide) solution by olfaction, varying degrees of injuries were made to the lateral olfactory tract, a major central olfactory pathway connecting the olfactory bulb to the olfactory cortex. After examining their olfactory ability to discriminate cycloheximide solution from water, intact bulbar projection neurons (mitral cells) with fiber connections to the olfactory cortex were quantified using a retrograde fiber tracing technique. The numbers of retrogradely labeled mitral cells from the rats with normal olfaction ranged between 20 and 92% of the control value, while those numbers from the anosmic rats ranged between 0 and 22%. We conclude that the functionally essential neuronal population is approximately one-fifth of the total in the central olfactory pathway, a presumed threshold value in terms of the ability to avoid cycloheximide solution by olfactory discrimination.

[Guideline of antimicrobial therapy in the area of cardiovascular surgery]

Although cardiovascular surgery is considered to be aseptic, prolonged hospital stay before and after surgery, the use of artificial materials and cardiopulmonary bypass, long-term use of intratracheal tubes or intravenous catheters, and an increase in surgeries on high-risk patients increase the incidence of postoperative infections. Therefore meticulous management to minimize bacterial contamination before and after surgery and identification of patient risk factors are important to reduce their incidence and severity, in addition to optimal antimicrobial therapy. As the targets of prophylactic antibiotics are usually superficial and environmental bacteria, those of choice are first or second-generation cephalosporins or penicillin with sulbactam. If postoperative infection is suspected, identification of the infectious site and pathogens and their susceptibility to anitimicrobials is useful to control infections. The use of broad-spectrum antibiotics is not recommended because these drugs induce bacterial resistance to antibiotics. Infectious endocarditis (IE) and deep wound infections, such as mediastinitis, are major serious infections after cardiovascular surgery. Antibiotics should be selected by considering the susceptibility of pathogens and pharmacokinetic properties of antibiotics, such as concentration in infected tissue. In patients reluctant to medical therapies, surgical intervention such as valve repair or replacement in IE and debridement and omental flap in mediastinitis should be considered.

The Japanese Study Group of Insulin Therapy for Childhood and Adolescent Diabetes (JSGIT): initial aims and impact of the family history of type 1 diabetes mellitus in Japanese children

The Japanese Study Group of Insulin Therapy for Childhood and Adolescent Diabetes (JSGIT) was established in July 1994 with the chief aim to improve the quality of therapy for type 1 diabetes in children, an entity far less common in Japan than in Europe. We proposed four initial research topics: (i) to determine the current status of medical care and glycemic control in Japanese children with type 1 diabetes mellitus; (ii) to standardize the measurement of hemoglobin A1c; (iii) to establish a registry of a large cohort of patients in order to enable prospective studies to improve the quality of therapy for children with type 1 diabetes in Japan; and (iv) to enable participants of the JSGIT to hold a workshop twice annually. We registered a total of 736 patients from 45 hospitals throughout Japan. Intervention via insulin treatment was instituted after 2 yr for those patients whose hemoglobin A1c level was more than 8.1%. The proportion of patients receiving multiple insulin injections increased after intervention; however, average hemoglobin A1c in females remained significantly higher than in males. We identified two forms of diabetes in Japanese children: a rapidly progressive form and a more slowly progressive form. There was a significantly higher prevalence of a family history of diabetes in first-degree relatives in the slowly progressive form. These preliminary findings are the result of the first collaborative study of childhood diabetes in Japan.

STK11/LKB1 Peutz-Jeghers gene inactivation in intraductal papillary-mucinous neoplasms of the pancreas

Despite the growing awareness of intraductal papillary-mucinous neoplasms (IPMNs) of the pancreas among clinicians, the molecular features of IPMNs have not been well characterized. Previous reports suggest that inactivation of the STK11/LKB1, a tumor-suppressor gene responsible for Peutz-Jeghers syndrome (PJS), plays a role in the pathogenesis of gastrointestinal hamartomas as well as several cancers, including pancreatic adenocarcinoma. Using polymerase chain reaction amplification of five microsatellite markers from the 19p13.3 region harboring the STK11/LKB1 gene, we analyzed DNA from 22 IPMNs for loss of heterozygosity (LOH). LOH at 19p13.3 was identified in 2 of 2 (100%) IPMNs from patients with PJS and 5 of 20 (25%) from patients lacking features of PJS (7 of 22, 32% overall). Sequencing analysis of the STK11/LKB1 gene in these IPMNs with LOH revealed a germline mutation in one IPMN that arose in a patient with PJS and a somatic mutation in 1 of the 20 sporadic IPMNs. None of the 22 IPMNs showed hypermethylation of the STK11/LKB1 gene. These results suggest that the STK11/LKB1 gene is involved in the pathogenesis of some IPMNs.

Renal mineral handling in normal rats treated with sevelamer hydrochloride (Renagel), a noncalcemic phosphate binder

The effects of sevelamer hydrochloride (Renagel); hereafter referred to as sevelamer), a noncalcemic phosphate binder, on renal mineral handling were examined in rats. Normal rats were fed a diet containing 0.3, 1, 3, and 5% sevelamer for 8 days, and serum, urine, and the immunohistochemical localization of the type II Na/Pi cotransporter protein in the kidney were analyzed. Rats treated with 3 or 5% sevelamer showed significant decreases in serum phosphorus (P) and parathyroid hormone (PTH) levels, with no changes in serum calcium (Ca), magnesium (Mg), or 1,25(OH)2D3 levels. Increases were observed in urinary excretions of Ca and Mg associated with a reduction in the PTH level in rats treated with 3 or 5% sevelamer. Rats treated with 1% or higher concentrations of sevelamer showed significant dose-dependent and marked reductions of the urinary P excretion, and the tubular reabsorption of P was maximized to almost 100% in the 5% sevelamer group. The hypophosphaturia in rats treated with 3 or 5% sevelamer was accounted for by the reductions in serum PTH and P per se, and immunohistochemical analysis showed that the expression of type II Na/Pi cotransporter protein was markedly increased at the brush border membranes of the deep and superficial nephrons in rats treated with 5% sevelamer as compared with rats given a normal diet. In conclusion, sevelamer rapidly lowered serum P and PTH levels in normal rats. Sevelamer treatment also produced a marked hypophosphaturia associated with translocation of type II Na/Pi cotransporter protein and increased urinary Ca and Mg excretions by the reduction of PTH.

[A study on the isolation period of patients with metastatic thyroid cancer treated by 131I according to a new guideline]

In Japan, a new guideline for the release of patients administered 131I was issued by the Ministry of Welfare on June, 1998: The dose rate is under 30 microSv/h at 1 m or the activity in the body is under 500 MBq. This study was designed to set the appropriate isolation period enough to satisfy these limits. A total of 28 patients with the history of total thyroidectomy and metastasis were selected for this study. In these patients, 28 patients were treated with oral administration of 3.7 GBq of Na131I (72 times), and one of 28 patients was once treated with 5.55 GBq of Na131I. Two of them were also received a total of 4 courses of a split dose therapy of 3.7 GBq of Na131I (740 MBq once a week for 5 consecutive weeks = one course). Measurements of the external exposure dose (microSv/h) at 1 m and the urinary excretory radioactivity (MBq) were performed at various times. There was a good correlation of the external exposure dose between standing (x microSv/h) and sitting (y microSv/h) postures (y = 0.99x + 0.406, r = 0.99, p < 0.0001, n = 169). The difference in the external exposure dose before and after urination (x microSv/h) had a significant correlation with the urinary excretory radioactivity (y MBq); y = 16.6x + 24.8, r = 0.96, p < 0.001, n = 41. Also, there was a significant correlation between the predicted value of residual radioactivity in the body (y' MBq) and the external exposure dose (x' microSv/h); y' = 20.8x' + 31.5, r = 0.98, p < 0.001, n = 77. In the patients treated with 3.7 GBq of Na131I, the mean and S.D. values of the external exposure dose (microSv/h) changed as follow: After 6 hr, 168 +/- 40; 24 hr, 52 +/- 23; 48 hr, 20 +/- 15; 72 hr, 10 +/- 9; and 96 hr, 8 +/- 9. The percentages of the patients satisfied the new guideline were as follow; 21.7% at 24 hr, 81.2% at 48 hr and 100% after 72 hr. Therefore the 3-day isolation is sufficient for the patients administered 3.7 GBq of Na131I.