Changes in the H-reflexes of ankle extensor and flexor muscles at the initiation of a stepping movement in humans

The underlying neural mechanisms of the silencing of electromyographic (EMG) activity observed between antagonistic muscles of the human ankle joint preceding a fast stepping movement were examined. Twelve subjects were asked to perform a unilateral stepping movement under a reaction time condition while standing upright. A silent phase (SP) which was composed of the time difference between the offset of tonic soleus (Sol) activity and the onset of phasic tibialis anterior (TA) activity was observed consistently in all subjects. At the time interval corresponding to the SP, inhibition of the Sol Hoffmann reflex (H-reflex) and facilitation of the TA H-reflex took place. In nine of the 12 subjects, disynaptic reciprocal Ia inhibition (Ia inhibition) from TA Ia fibers to the Sol motoneuron (MN) pool increased before the TA EMG onset. We also observed a clear distinction between the changes in the time course of the Ia inhibition and that of long latency reciprocal (D1) inhibition in six of the 12 subjects. However, when the subjects performed the same motor task with their backs supported against a wall wherein the tonic Sol activation disappeared, no changes in the H-reflex occurred. These results suggest that these changes, occurring at the segmental level, might be controlled by the supraspinal motor center in a feed-forward manner during anticipatory postural adjustment. The functional significance would be to counterbalance the disturbance from an intentional forthcoming movement in order to maintain an adequate posture.

Changes in the number and apoptosis of epithelial cells in the colorectum of wheat bran-fed rats soon after administering 1,2-dimethylhydrazine

We investigated the effect of dietary wheat bran (Wb) on colonic tumorigenesis soon after a single administration of 1,2-dimethylhydrazine (DMH). Rats that had been fed on either a fiber-free diet or a 20% Wb diet were injected with 1,2-dimethylhydrazine (20 mg/kg body weight). At 6h, 12h, 1d, 3d, or 7d after the injection, the colorectum was excised for histological analyses. The number of crypt cells more rapidly recovered in the 20% Wb group than in the fiber-free group after its temporary reduction by injection of DMH. At 6h after the DMH treatment, the apoptotic cells were significantly greater in number in the fiber-free group than in the 20% Wb group. In contrast, those in distal colon were significantly fewer in the fiber-free group than in the 20% Wb group at 7d after the treatment. These results suggest that the ingestion of Wb affected the turnover of colonic epithelial cells and would thereby bring about a protective effect against DMH-induced tumorigenesis.

Motor evoked potentials (MEPs) and H-reflexes are not equally sensitive to voluntary motor commands

To investigate the sensitivity to changes in excitability of motoneuron pool dependent on voluntary motor commands, we recorded motor evoked potentials (MEPs) and H-reflexes from the right flexor carpi radialis (FCR) muscle of normal human subjects. Amplitudes of MEPs were always larger than those of the H-reflex in both tonic and phasic muscle contractions. Furthermore, amplitudes of MEP and H-reflex were larger in phasic than in tonic muscle contraction. These results indicate that there are differences in the sensitivity to changes in motoneuronal excitability related to the production of excitatory postsynaptic potentials for H-reflex and MEP responses, respectively.

Expression of matrix metalloproteinase (gelatinase) in T1 adenocarcinoma of the lung

The expression of matrix metalloproteinase-2 (MMP-2; 72 kDa type IV collagenase/gelatinase A) and MMP-9 (92 kDa type IV collagenase/gelatinase B) was immunohistochemically investigated in 79 T1 adenocarcinomas of the lung using non-commercial polyclonal anti-MMP-2 and -9 antibodies. Thirty-two (41%) and 22 (28%) among the 79 cases were positive in the tumor cells for MMP-2 and -9, respectively. The incidences of MMP-2 and -9 immunoreactivities were higher (64 and 45%, respectively) in poorly differentiated tumors than in well differentiated tumors (36 and 25%, respectively), and lower in bronchioloalveolar carcinoma (22 and 10%, respectively) compared with other subtypes of adenocarcinoma. The prognosis for patients with MMP-2 and/or -9 positive immunoreactivities was significantly poorer than for those with a MMP-negative tumor (P < 0.05). The degree of collagenization was divided into four grades, and tumors with a small to abundant amount of collagen (grade 2 and grade 3 fibrosis) had a higher incidence of immunoreactivity to both types of MMP. It is estimated that these expressions might be responsible for tumor invasion, metastasis, and for grade 2 and grade 3 fibrosis in T1 adenocarcinoma of the lung.

Tyrosine phosphorylation of 100-115 kDa proteins by phosphatidic acid generated via phospholipase D activation in HL60 granulocytes

In HL60 granulocytes, 4beta-phorbol 12-myristate 13-acetate (PMA) induced tyrosine phosphorylation of several proteins with molecular weight of 100-115 kDa and 45 kDa. Furthermore, PMA-mediated phosphatidic acid (PA) production via phospholipase D (PLD) activation. In the presence of either butanol or ethanol, PMA-induced PA production was markedly reduced and instead a metabolically stable phosphatidylbutanol (PBut) or phosphatidylethanol (PEt) was produced by transphosphatidylation by PLD. Under the same incubation condition, these primary alcohols inhibited PMA-induced tyrosine phosphorylation of the 100-115 kDa proteins. Propranolol, which is often used as a selective inhibitor of PA phosphohydrolase (PAP) involving diacylglycerol (DG) formation from PA, did not affect tyrosine phosphorylation of the 100-115 kDa proteins. Moreover, incubation of HL60 granulocytes with Streptomyces chromofuscus PLD caused both PA production and tyrosine phosphorylation of the above proteins. Exogenous PA treatment also induced tyrosine phosphorylation of the same proteins. Thus, the results presented here suggest that PA produced via PLD activation is involved in tyrosine phosphorylation of the 100-115 kDa proteins in HL60 granulocytes.

Cerebral infarction in incontinentia pigmenti: the first report of a case evaluated by single photon emission computed tomography

A 2-month-old girl with incontinentia pigmenti presented with acute-onset right-handed focalized seizures and subsequent seizure generalization. Computed tomography, magnetic resonance imaging and single photon emission computed tomography results indicated that she had multiple cerebral infarctions. These findings suggest that incontinentia pigmenti should be included among the neurocutaneous syndromes associated with ischemic strokes in childhood. This is the first report of a case with incontinentia pigmenti associated with cerebral infarction evaluated by single photon emission computed tomography.

Changes in messenger RNA of pancreatic enzymes and intestinal cholecystokinin after a 7-day bile-pancreatic juice diversion from the proximal small intestine in rats

We have previously demonstrated the bile-pancreatic juice (BPJ)-independent stimulation of pancreatic enzyme secretion in chronic BPJ-diverted rats. Pancreatic and intestinal adaptation to 7-day BPJ diversion was next examined. Pancreatic enzyme mRNA and cholecystokinin mRNA in the jejunal mucosa were measured in rats with BPJ diverted into the ileum (PBD rats) in comparison with the figures for rats with BPJ returned to the duodenum (normal rats) or laparotomized (Intact) rats under well-nourished conditions. Amylase mRNA in the pancreas was lower and trypsinogen plus chymotrypsinogen mRNA was higher in the PBD rats than in the intact rats. The change in pancreatic mRNA was similar to that in the specific activities of the enzymes after a chronic BPJ diversion. This finding suggests that these pancreatic enzymes were regulated by the mRNA level. The portal concentration of cholecystokinin in the postabsorptive period (exogenously non-stimulated status) was 4-fold higher in the PBD group than in the normal and intact groups. Cholecystokinin mRNA in the jejunal mucosa of PBD rats was somewhat higher than that of intact rats. These results suggest that intestinal cholecystokinin was predominantly increased at the translational or later stage by chronic BPJ diversion.

HTLV-I induced myeloneuropathy in WKAH rats: apoptosis and local activation of the HTLV-I pX and TNF-alpha genes implicated in the pathogenesis

To investigate the pathogenesis of HTLV-I associated diseases, we established a rat model for HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) in WKAH rats. In the spinal cords of WKAH rats carrying HTLV-I, chronological histopathology revealed the occurrence of apoptotic cell death starting at 9 months after the infection, followed by demyelination, macrophage infiltration, and the activation of astrocytes starting at 12, 15 and 20 months, respectively. Apoptosis of the Schwann cells was also observed in the peripheral nerves of these rats. By RT-PCR, pX mRNA of HTLV-I was selectively expressed in the diseased spinal cords and peripheral nerves, but not in the unaffected cerebra, cerebella, even though provirus DNAs were consistently identified in these tissues. Among several cytokines examined, mRNA expression and production of TNF-alpha were frequently detected in the spinal cord and the cerebrospinal fluid. The collective evidence suggests that the selective activation of HTLV-I, in particular Tax expression, and/or the production of TNF-alpha in target spinal cord and peripheral nerves are causally related to apoptotic death of the oligodendrocytes and Schwann cells, a major pathogenetic pathway of HTLV-I induced myeloneuropathy in the WKAH rat.

[Useful treatment modality for postoperative duodenal fistula with somatostatin analogue]

A case with leakage of duodenal stump treated by a somatostatin analogue (SMS 201-995,SMS) effectively was reported. A 39-year-old man had underwent gastric resection (Billroth I) and distal pancreaticojejunostomy for transsection of duodenal bulbus and pancreatic body. After 14 days later duodenal diverticulization was performed due to anastomotic stricture of the gastro-duodenostomy, which resulted in leakage of duodenal stump and voluminous fluids from drains were lasting about 5 weeks. Amylase (AMY) value was shown as high as 703,812 U/l in the exudate. SMS was injected by 100 micrograms, s, c, by three times a day for 24 days. The volume of exudate decreased immediately after the administration of SMS and to one-half in volume in 2 weeks. AMY also fell to 42, 378 U/l. The drain was removed two months after the third surgery. The patient was discharged on post operative day 200. SMS was known to inhibit secretion of bile and intestinal as well as pancreatic juice and its usefulness for leakage of the intestinal tract, especially of the duodenum, is suggested.

Models of HTLV-I-induced diseases. Infectious transmission of HTLV-I in inbred rats and HTVL-I env-pX transgenic rats

To examine the pathogenic roles of HTLV-I in HTLV-I-induced diseases, we developed two models; namely HTLV-I carrier rats and HTLV-I env-pX transgenic rats. Among life long HTLV-I carriers in seven rat strains, only WKAH rats with the RT1k haplotype developed chronic progressive myeloneuropathy, resembling HAM/TSP clinically and histologically in humans, designated as HAM rat disease and after long incubation periods. Apoptosis of myelin forming cells, oligodendrocytes and Schwann cells associated with HTLV-I infection appears to be the primary cause of HAM rat disease. Local activation of the pX gene and TNF alpha gene was evident in these rats. WKAH rats transgenic for HTLV-I env-pX gene were established and at age 5 weeks, swelling of the bilateral ankle joints began to develop and histological features of the affected joints resembled findings in cases of rheumatoid arthritis (RA): high-titers of rheumatoid factors were present in these rats. A series of vascular collagen diseases such as polyarteritis nodosa-like angiitis, polymyositis, myocarditis, and Sjögren's syndrome-like sialodenitis together with RA were present, even in one individual animal. These transgenic rats as well as HAM rats appear to be suitable animal models for elucidating pathogenic mechanisms implicated in HTLV-I-induced diseases and also various demyelinating vascular collagen diseases of unknown etiology.

Effect of oocyte retrieval from a small leading follicle in fixed-schedule in vitro fertilization program

OBJECTIVE

To evaluate the propriety of oocyte retrieval (OR) form a small leading follicle during a fixed-schedule in vitro fertilization (IVF) program.

METHODS

OR was fixed only to take place on Wednesdays. Gonadotropin-releasing hormone agonist treatment was initiated on the first day of the cycle, human menopausal gonadotrophin was given for 7 days starting on the next Monday, and human chorionic gonadotrophin (hCG) was given on the Tuesday before the OR. Patients were divided into 2 groups according to the follicular size observed before the day of hCG administration: Group 1 (141 cycles), with follicles > 16 mm in mean diameter; and Group 2 (38 cycles) with follicles of 10 to 16 mm in mean diameter.

RESULTS

Fertilization rates and the incidence of mature oocytes were higher in Group 1 than in Group 2. However, the mean number of oocytes recovered and pregnancy rates were similar in the 2 groups.

CONCLUSION

It is worthwhile to retrieve the oocyte from a small leading follicle in a fixed-schedule IVF program.

Supplementation of methionine to a low soybean protein diet strikingly increases pancreatic amylase activity in rats

Feed efficiency in rats fed a low soybean protein isolate (SPI) diet (100 g/kg diet) was dramatically improved with the supplementation of L-methionine (3 g/kg diet). Pancreatic amylase activity was low in rats fed a low SPI diet, and was much higher in the supplemented group than in the non-supplemented group. Pancreatic trypsinogen and chymotrypsinogen contents (as activities of trypsin and chymotrypsin) were not changed with the methionine supplementation. In the small intestine, sucrase and leucine aminopeptidase in the jejunum and ileum were not clearly changed. In conclusion, a small amount of methionine supplemented to a low SPI diet especially induced pancreatic amylase among digestive enzymes. The factor involved in nutritional status, not the physiological action of methionine itself, may contribute the induction of amylase.

Metabolic activation of 2- and 3-nitrodibenzopyranone isomers and related compounds by rat liver S9 and the effect of S9 on the mutational specificity of nitrodibenzopyranones

The effect of rat liver S9 on the mutagenicity of 10 nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) was evaluated with Salmonella typhimurium TA98NR using S9 from phenobarbital-, 3-methylcholanthrene (MC)-, beta-naphthoflavone- and polychlorobiphenyl-treated and untreated rats. 2-Nitrofluorene (2-NFI), 2-nitrofluoren-9-one (2-NFlone), 2-nitrocarbazole (2-NCz), 3-NCz, 2-nitrodibenzothiophene (2-NDBT), 2-nitro-6H-dibenzo[b,d]pyran-6-one (2-NDBP) and 3-NDBP were metabolically activated by one or more of the S9 fractions, and the highest enhancement of the mutagenic potency of nitro-PAHs was observed with 3-MC-induced S9. Only in the case of 3-NFlone was the mutagenicity in strain TA98NR decreased by the addition of S9, regardless of S9 induction. 2-NDBP was most efficiently activated among nitro-PAHs tested by all S9 fractions used. The cytosolic fraction of S9 accounted for more of the activation of 2-NDBP than the microsomal fraction. NADH and NADPH were the most effective electron donors on the activation of 2-NDBP by S9, 2-NDBP was also metabolically activated by NADH plus commercial preparations of xanthine oxidase. These activations of 2-NDBP were inhibited by allopurinol, indicating that cytosolic xanthine oxidase in rat liver S9 participates in the activation of 2-NDBP. The potency of 2- and 3-NDBP isomers as base-substitution mutagens was also enhanced by S9. In the presence of S9, both compounds showed the highest mutagenicity in strain TA7005 (C.G-->A.T) followed by strains TA7004 (G.C-->A.T), TA7006 (C.G-->G.C) and TA7002 (T.A-->A.T), and this mutation specificity was similar to that without S9, indicating that the mechanism of mutagenesis caused by NDBP isomers with S9 is similar to that without S9.

Evidence for facilitation of motor evoked potentials (MEPs) induced by motor imagery

This study examined the extent to which motor imagery can facilitate to specific pools of motoneurons. Motor commands induced by motor imagery were subthreshold for muscle activity and were presumably not associated with any change in background afferent activity. To estimate excitability changes of flexor carpi radialis (FCR) muscle motoneuron in spinal and cortical level, electric stimuli for recording H-reflex and transcranial magnetic stimulation (TMS) for recording motor evoked potentials (MEPs) were used. During motor imagery of wrist flexion, remarkable increases in the amplitude of the MEP of FCR were observed with no change in the H-reflex. Furthermore, facilitation of antagonist (extensor carpi radialis; ECR) was also observed. Therefore, it is concluded that internal motor command can activate precisely cortical excitability with no change in spinal level without recourse to afferent feedback.

Phase I study of sequentially administered topoisomerase I inhibitor (irinotecan) and topoisomerase II inhibitor (etoposide) for metastatic non-small-cell lung cancer

We conducted a phase I study of irinotecan (CPT-11) and etoposide (VP-16) given sequentially to untreated patients with metastatic non-small-cell lung cancer. Arm A: CPT-11 was given over 90 min on days 1-3 and VP-16 was given over 60 min on days 4-6. Arm B: VP-16 was given on days 1-3 and CPT-11 on days 4-6. G-CSF was given to all patients daily on days 7-17. Twenty-seven patients were entered randomly at the two arms. The major dose-limiting toxicities in arms A and B were granulocytopenia and diarrhoea. Transient elevations of transaminases and bilirubin were observed in both arms. The degree of the toxicities did not differ between the two arms. The maximum tolerated doses (MTDs) were 60 mg m-2 CPT-11 and 60 mg m-2 VP-16 in both arms. Of the 13 patients who received more than two cycles, two out of five achieved partial response (PR) at the first level of arm A and one out of four achieved PR at the second level of arm B. We conclude that these schedules of sequential CPT-11 and VP-16 administration were inappropriate because of severe toxicities.

Serum levels of pro-gastrin-releasing peptide for follow-up of patients with small cell lung cancer

To assess the clinical usefulness of serum pro-gastrin-releasing peptide (Pro-GRP) as a tumor marker for small cell lung carcinoma (SCLC), we measured serum levels of Pro-GRP with a newly developed ELISA and measured serum levels of neuron-specific enolase (NSE) in 44 patients with untreated SCLC and 77 patients with untreated non-SCLC. We prospectively measured serum levels of Pro-GRP and NSE in SCLC patients after initial treatment until relapse. The sensitivity (70%) and specificity (91%) of Pro-GRP were similar to those of NSE (70 and 86%). Thirty-nine % of patients who had a partial response still had elevated serum levels of Pro-GRP at the time of restaging after initial treatment. In follow-up study, 94% of patients had elevated serum levels of Pro-GRP again at the time of relapse, whereas 37% of patients showed elevated levels of NSE. Levels of Pro-GRP increased a median of 35 (-95 to 151) days before clinical evidence of relapse was detected with successive physical examinations and imaging studies, whereas levels of NSE increased 20 (-85 to 124) days after relapse was detected (P < 0.05). Pro-GRP was helpful as a diagnostic aid and a marker for therapeutic effect and relapse in patients with SCLC, supplemented to serum NSE.

Chronopharmacology of etoposide given by low dose prolonged infusion in lung cancer patients

We examined the chronopharmacology of prolonged etoposide administration by intravenous infusion over 14 days in 9 patients with lung cancer. Blood samples were obtained every 4 hours between 24 hours and 48 hours after initiation of the infusion. Using the unpaired t-test, the percentage plasma etoposide concentration at 09:00 hours calculated from the 24 hour average value, was significantly higher than that at 21:00 hours (p = 0.024). However, neither ANOVA nor cosinor analysis revealed any significant effect of sampling time (ANOVA: p = 0.29, cosinor analysis: p = 0.46).

The effect of ulinastatin on CFU-C colony formation in mouse myelocyte cultures

The effect of ulinastatin, a protease inhibitor, on hematopoiesis was studied. Ulinastatin was found to increase the number of colony forming units of mouse myelocytes in culture, suggesting that it might promote hematopoiesis.

Administration of anti-asialo GM1 serum increases aberrant crypt foci induced by 1,2-dimethylhydrazine in the large bowel of rats

We investigated the influence of the administration of anti-asialo GM1 antibody on aberrant crypt foci (ACF) formation induced by a single injection of 1,2-dimethylhydrazine (DMH). At four weeks after the injection of DMH (20 mg/kg body weight), the number of ACF and aberrant crypts were counted. Most ACF appeared in the distal large bowel, accounting for approximately 60% of the total ACF in both groups. Rats administered anti-asialo GM1 had significantly more ACF in the distal colon, the rectum and the total large bowel as compared to control rats. A similar tendency was observed for the number of aberrant crypts. The increased number of ACF resulting from the administration of anti-asialo GM1 was not accompanied by the enlargement of ACF size in every part of the colon. This study demonstrated that the administration of anti-asialo GM1 at the initiation stage leads to an increase in ACF as well as aberrant crypts in the distal colon, rectum and total large bowel probably via the suppression of natural killer cells.

Inhibitory effect of dietary wheat bran on formation of aberrant crypt foci in rat colon induced by a single injection of 1,2-dimethylhydrazine

The frequency of appearance of aberrant crypt foci (ACF) in the distal colon was significantly lower in rats fed a high fiber (20% wheat bran) diet than in those fed a fiber-free one at 4 weeks after a single injection of 1,2-dimethylhydrazine (DMH, 20 mg/kg), although crypt/ACF was high in the former relative to the latter. This result suggests that dietary wheat bran effectively serves as a regulator of ACF frequency at early stages after DMH injection.

Increases in calcium absorption with ingestion of soluble dietary fibre, guar-gum hydrolysate, depend on the caecum in partially nephrectomized and normal rats

Effects of feeding soluble dietary fibre on apparent Ca absorption and the contribution of the caecum to Ca absorption were examined in five-sixths nephrectomized (NPX) and normal rats with or without caecectomy in four experiments. It is known that Ca absorption is lowered by renal failure. In the first experiment the amounts of femur Ca increased linearly with increasing dietary Ca up to 3.0 g Ca/kg diet in intact rats. Partial nephrectomy decreased apparent Ca absorption in rats fed on diets containing 3-0 and 4.5 g Ca/kg diet. In the NPX groups, Ca absorption in rats fed on the diet containing guar-gum hydrolysate (GGH; 50 g/kg diet; 3.0 g Ca/kg diet) was significantly higher than that in rats fed on a fibre-free diet, and the increase in Ca absorption with GGH feeding was completely abolished by caecectomy. Also, ingestion of GGH increased Ca absorption in normal rats, but not in normal, caecectomized rats. Mg absorption was also increased with GGH feeding and was decreased with caecectomy in NPX and normal rats. In experiments which used caecectomized rats, coprophagy was prevented with an anal cup to avoid re-ingestion of faecal Ca. We conclude that ingestion of the soluble dietary fibre, GGH, increased apparent Ca absorption in NPX and non-NPX rats, and the caecum was responsible for these increases in Ca absorption.

Lack of response to dietary protein in pancreatic secretion by chronic deprivation of jejunal chyme in rats

BACKGROUND

Exocrine pancreatic secretion is regulated by luminal factors, bile-pancreatic juice (BPJ), and food chyme. The effects of 10 days' chronic deprivation of luminal chyme on the stimulation of exocrine pancreatic secretion by dietary protein were examined in rats with or without BPJ in the jejunum.

METHODS

The jejunum was deprived of ingested food by preparing a whole-jejunum blind loop. The BPJ was diverted by a common bile-pancreatic duct catheter and was returned to the upper jejunum (with BPJ) or ileum (without BPJ).

RESULTS AND CONCLUSION

In rats with the ingested food and BPJ in the jejunum (control), secretion rates in terms of volume, protein, amylase, and trypsin increased more than twofold from the rates in the fasting state after a jejunal injection of peptic hydrolysate of casein. In contrast, the secretions were not increased by the protein injection in the rats deprived of jejunal chyme with or without BPJ in the jejunum. Even in the chyme-deprived group the protein and trypsin secretion of the fasting state was significantly higher in BPJ-diverted rats than in rats with BPJ. These results showed that chronic deprivation of the jejunal chyme impaired responses of the exocrine pancreas to dietary protein but not the hypersecretions of the pancreas by BPJ diversion.

Epstein-Barr virus-associated gastric carcinoma

Epstein-Barr virus (EBV) is associated with certain types of gastric carcinoma. We report a case of EBV-positive undifferentiated carcinoma of the stomach in a 59-year-old woman with a well-demarcated ulcerating tumor in the gastric body. Examination of the resected stomach revealed that the tumor was undifferentiated carcinoma with lymphoid stroma, or lymphoepithelioma-like carcinoma. Tumor cells were positive for EBV by in situ hybridization. Gastroenterologists must keep in mind that localized ulcerating tumors of the stomach histologically seen as undifferentiated carcinnoma with lymphoid stroma are linked to EBV infection.