Novel aberrant nuclear behavior in abortive conjugation of Tetrahymena thermophila: joint selection of a meiotic product and macronucleus during nuclear selection

In conjugation of Tetrahymena thermophila, the paroral zone, cortical cytoplasm in the vicinity of the cytostome, is the site where nuclear selection occurs; one of the four meiotic products is selected in this site prior to the production of gametic pronuclei. During inbreeding cross experiments, several sterile strains were obtained which showed aberrant nuclear behavior. Conjugants of these strains normally underwent meiosis, resulting in the generation of four meiotic products. They, however, failed to complete the process of nuclear selection and aborted the subsequent conjugation sequences. During nuclear selection, macronucleus was frequently selected instead of a meiotic product. A novel aberrant nuclear behavior was observed: Macronucleus and a meiotic product were jointly selected and the both nuclei simultaneously attached to the same paroral zone. When this simultaneous attachment occurred in one partner cell of a pair, nuclear selection was never observed in the other partner cell. This result suggests that a conjugating pair has only two attachment sites on the paroral zone during nuclear selection, and that the distribution of the sites is occasionally distorted in abortive conjugation.

Selective interaction of vitamin D receptor with transcriptional coactivators by a vitamin D analog

The nuclear vitamin D receptor (VDR) is a member of a nuclear receptor superfamily and acts as a ligand-dependent transcription factor. A family of cotranscriptional activators (SRC-1, TIF2, and AIB-1) interacts with and activates the transactivation function of nuclear receptors in a ligand-dependent way. We examined interaction of VDR with these coactivators that was induced by several vitamin D analogs, since they exert differential subsets of the biological action of vitamin D through unknown mechanisms. Unlike other vitamin D analogs tested, OCT (22-oxa-1alpha,25-dihydroxyvitamin D3) induced interaction of VDR with TIF2 but not with SRC-1 or AIB-1. Consistent with these interactions, only TIF2 was able to potentiate the transactivation function of VDR bound to OCT. Thus, the present findings suggest that the structure of VDR is altered in a vitamin D analog-specific way, resulting in selective interactions of VDR with coactivators. Such selective interaction of coactivators with VDR may specify the array of biological actions of a vitamin D analog like OCT, possibly through activating a particular set of target gene promoters.

[A case of vertebrobasilar dissection which was associated with progressing stroke and was successfully treated by intravascular surgery in the acute stage]

A case of vertebrobasilar dissection which deteriorated in the acute stage and was successfully treated by intravascular surgery is described. A 26-year-old male presented with sudden onset of occipitalgia, weakness of the right upper and lower extremities, and speech disturbance. He was transferred to our hospital 3 hours after the onset. On admission, neurological examination showed right hemiparesis including the face and dysarthria. CT of the head showed no definite abnormality and left vertebral angiograms (VAG) revealed only slight wall irregularity of the basilar artery. T2-weighted MR imaging demonstrated an area of high intensity in the left side of the pons. He was treated conservatively under a diagnosis of pontine infarction. On the 8th hospital day, he developed left hemiparesis. T2-weighted MR imaging revealed a new high intensity lesion in the opposite side of the pons. 3D-SPGR images showed double lumen of the left vertebral artery. Angiography showed that the wall irregularity of the basilar artery had become more obvious. These findings strongly suggested a dissection extending from the left vertebral artery to the basilar artery. Progression of the dissection was presumed to have caused the worsening in clinical symptoms, and further progression of the dissection would involve perforators of the basilar artery top and would be fatal. To prevent further progression of the dissection, the left vertebral artery was occluded at the proximal site of the orifice of the dissection with platinum coils after a test occlusion on the same day. Postoperatively, further deterioration of the clinical symptoms ceased. Left VAG on the 33rd postoperative day demonstrated improvement in the wall irregularity of the basilar artery. His clinical symptoms improved markedly and he was ambulatory at discharge and returned to his previous occupation. We emphasize that a progressive vertebrobasilar dissection that causes clinical deterioration in the acute stage can be prevented from progressing further by occlusion at the proximal site of the orifice of the dissection.

Effect of ischemic preconditioning on myocardial oxygen consumption during ischemia

Ischemic preconditioning (IPC) in the heart may reduce myocardial energy demand. The present study was undertaken to examine changes in myocardial oxygen consumption (MVO2) during ischemia by IPC in Langendorff perfused rat hearts. We assessed MVO2 during ischemia from the measurement of mitochondrial cyt. aa3 redox state by a two-wavelength reflectance spectrophotometry where T(1/2), the time from the onset of ischemia to the point for half reduction of cyt. aa3, was assumed to represent MVO2. The heart was preconditioned by three cycles of 5 min ischemia plus 5 min reperfusion and then subjected to 30 min global ischemia followed by reperfusion for 30 min. The T(1/2) was significantly longer in the preconditioned heart (30 +/- 6 s, n = 10) than the control heart (14 +/- 5 s, n = 9, P<0.001), indicating a reduction of MVO2 during ischemic period by IPC. The prolongation of T(1/2) was evident after only one IPC episode. When the heart was perfused with high K+ solution to abolish MVO2 for contractions, we still found the prolongation of T1(1/2) in the preconditioned heart (116 +/- 12 s, n = 6) compared to the control heart (86 +/- 10 s, n = 6, P<0.01), suggesting that decrease in contractile activity may be, in part but not completely, responsible for the reduction of MVO2. In contrast, the prolongation of T(1/2) was completely abolished by administration of a NO synthase inhibitor N omega-nitro-L-arginine in the high K+ arrested heart, demonstrating involvement of NO in the reduction of MVO2, presumably by suppression of mitochondrial respiratory chain. In conclusion, IPC reduces MVO2 during ischemia. The reduction of MVO2 in the preconditioned heart may be accounted for by decreased contractile activity and by depression of respiratory chain by NO.

[A comparative study of transcranial Doppler sonography and near-infrared spectroscopy for the assessment of cerebrovascular CO2 reactivity]

Simultaneous measurements of time averaged mean blood flow velocity in the right middle cerebral artery (Vmca) by transcranial Doppler sonography (TCD) and regional cerebral oxygen saturation (rSo2) by near-infrared spectroscopy (NIRS) were performed in 30 subjects under propofol /fentanyl/ oxygen anesthesia. End-tidal CO2 pressure (PetCO2) was controlled by adjusting minute ventilation. A paired measurements of Vmca and rSo2 was repeated at PetCO2 of 50, 45, 40, 35, 30, and 25 mmHg in each subject. Relative Vmca (rVmca) was also calculated as a relative expression of Vmca at PetCO2 of 40 mmHg. Linear regression analysis was applied to determine the individual best fit relationship of these, parameters. There were significant linear correlations between PetCO2 and Vmca (R > 0.94, P < 0.01), between PetCO2 and rVmca (R > 0.94, P < 0.01), between PetCO2 and rSo2 (R > 0.92, P < 0.01), and between rSo2 and Vmca (R > 0.88, P < 0.05) in each subject. Furthermore, there was a significant linear correlation between rVmca based CO2 reactivity and rSo2 based CO2 reactivity (R = 0.60, P < 0.001). These results indicate that measurements of rSo2 may be an alternative method for evaluating cerebrovascular CO2 reactivity when poor ultrasound window.

Thiopental inhibits increases in [Ca2+]i induced by membrane depolarization, NMDA receptor activation, and ischemia in rat hippocampal and cortical slices

BACKGROUND

This study examined the effects of thiopental on intracellular calcium ([Ca2+]i) changes induced by membrane depolarization, N-methyl-D-aspartate (NMDA) receptor activation, and ischemia.

METHODS

Experiments were performed in brain slices prepared from Wistar rats. [Ca2+]i measurements were taken on the CA1 pyramidal cell layer of the hippocampus or layers II to III of the somatosensory cortex using the fura-2 fluorescence technique. Membrane depolarization and NMDA receptor activation were induced by exposing slices to 60 mM K+ and 100 microM NMDA, respectively. In vitro ischemia was induced by superfusing slices with glucose-free Krebs solution equilibrated with 95% nitrogen and 5% carbon dioxide. Thiopental was applied 5 min before application of high K+ and NMDA, or before in vitro ischemia.

RESULTS

Ischemia for 15 min produced a characteristic [Ca2+]i increase in both hippocampal and cortical slices. Thiopental prolonged the latency to the appearance of the [Ca2+]i plateau and reduced the magnitudes of increase in [Ca2+]i 8, 10, and 15 min after the onset of ischemia. Thiopental also suppressed the high K+- and NMDA-induced [Ca2+]i increases. The NMDA-induced [Ca2+]i increases were attenuated to a greater extent in cortical slices than were those in hippocampal slices. The inhibition of thiopental on the 200-microM NMDA-mediated [Ca2+]i response was confirmed in cultured cortical neurons.

CONCLUSIONS

The results indicate that thiopental attenuates ischemia-induced [Ca2+]i increases in the hippocampus and cortex in vitro, probably because of its inhibition of both voltage-gated calcium channels and NMDA receptors. The regionally different inhibition of thiopental on NMDA receptors may relate to its region-specific action against ischemia.

Direct observation of radial intracellular PO2 gradients in a single cardiomyocyte of the rat

The purpose of the present study was to directly visualize radial gradients of intracellular PO2 in a single individual cardiomyocyte isolated from the rat ventricle. Microspectrophotometry with the use of cytosolic myoglobin as an oxygen probe was conducted at 410 nm. When the quiescent cell was incubated with 1 microM carbonyl cyanide m-chlorophenylhydrazone to increase oxygen consumption approximately eightfold, gradual decreases in myoglobin oxygen saturation (SMb) were demonstrated toward the core of the cell, whereas these decreases disappeared when the cell was treated with 2 mM NaCN. These results highlighted the importance of diffusional oxygen transport in determining intracellular oxygenation in cardiac cells. From the measured SMb, we assessed the profile of radial changes in intracellular PO2 at the mean SMb comparable to that in vivo ( approximately 0.5). Quite steep PO2 gradients were demonstrated in the vicinity of the sarcolemma that were rapidly attenuated toward the cell core. These radial profiles of intracellular PO2 demonstrate the significance of myoglobin-facilitated diffusion of oxygen. Furthermore, the shallow gradients of PO2 near the center of the cell might arise from partial depression of oxygen consumption near the cell core.

A novel isoform of rat estrogen receptor beta with 18 amino acid insertion in the ligand binding domain as a putative dominant negative regular of estrogen action

A novel isoform of rat estrogen receptor (ER) beta, ER beta 2, which is a putative alternative splicing product of the reported ER beta (ER beta 1) has been identified. Rat ER beta 2 cDNA contains an additional, in-frame 54 base pair insertion in the ligand binding domain of ER beta 1, which generates an 18 amino acid residue insertion. Northern blot and RT-PCR analyses revealed that ER beta 2 coexists with ER alpha and ER beta 1 in all tissues examined including brain, lung, liver, kidney, fat, bone, uterus, prostate, and ovary. The insertion caused loss of ligand binding activity of ER beta 2, whereas the ability to bind the palindromic estrogen response element (ERE) was retained. In an ERE-containing luciferase reporter gene assay using COS-1 cells, ER beta 2 failed to activate estrogen-dependent transcription. Furthermore, ER beta 2 dose dependently suppressed the ER alpha- and ER beta 1-mediated transcriptional activation. These results suggest that rat ER beta 2 functions as a negative regulator of estrogen action.

Novel mutations of the peripheral myelin protein 22 gene in two pedigrees with Dejerine-Sottas disease

Peripheral myelin protein 22 (PMP22), a membrane glycoprotein, plays a significant role in the formation and/or maintenance of compact myelin in the peripheral nervous system. We studied two pedigrees with Dejerine-Sottas disease and identified two novel mutations in the PMP22 gene: one a 2-bp deletional mutation at nucleotide positions 426 and 427 of exon 4 (this is predicted to alter the reading frame at leucine 80 and thus to lead to frame-shifted translation), and the other a guanine to thymine substitution at nucleotide position 636 leading to a cysteine substitution for glycine 150. Both mutations were located in the putative transmembrane domains reported in many cases of Charcot-Marie-Tooth neuropathy, Dejerine-Sottas disease, and hereditary neuropathy with liability to pressure palsies. The results suggest an important role for the putative transmembrane domains of PMP22 in its function.

Headache after attempted epidural block: the role of intrathecal air

BACKGROUND

Postmeningeal puncture headache (PMPH) is typically attributed to the loss of cerebrospinal fluid (CSF). However, when it occurs after an attempted epidural puncture, it may be due to either CSF loss or, potentially, to the subarachnoid injection of air used as a part of "loss-of-resistance" testing. This study was performed to examine the relation between intrathecal air and PMPH.

METHODS

Using a loss-of-resistance test with an air-filled (n = 1,812; air group) or saline-filled (n = 1,918; saline group) syringe, epidural block was performed in patients with acute or chronic pain. The dura was judged to be perforated not only when backflow of CSF was recognized in the needle but also when signs and symptoms solely attributable to meningeal perforation were seen, such as high spinal blockade or severe motor blockade. The incidence, onset time, and duration of PMPH in the air and saline groups were compared. In all patients with signs of meningeal perforation, brain computed tomography was examined.

RESULTS

The incidence of PMPH in the air group (32 cases) was significantly higher than that in the saline group (5 cases), although the occurrences of meningeal perforation between the air (48 cases) and saline (51 cases) groups did not differ significantly. Intrathecal air bubbles were detected on brain computed tomography in both the deep supraspinal structures such as the ventricles, Silvian fissures and cisterns, and the superficial subarachnoid space in 30 of 32 patients with PMPH in the air group, whereas no intrathecal air bubbles were seen in the saline group. PMPH was significantly more rapid in onset and shorter in duration in the air group than that in the saline group.

CONCLUSIONS

The use of air for loss-of-resistance testing during epidural block was associated with a higher incidence of PMPH, which might be attributable to subarachnoid air injection and CSF leakage.

The effect of dialysate glucose on phagocyte superoxide generation in CAPD patients

OBJECTIVE

In the present study, we investigated the influence of dialysate glucose on superoxide (O2-) generation by peripheral and peritoneal phagocytes in continuous ambulatory peritoneal dialysis (CAPD) patients.

DESIGN

Peripheral polymorphonuclear leukocytes (PMNL) and mononuclear leukocytes (MNL), and peritoneal cells were isolated from peripheral blood and peritoneal effluents, respectively, and their oxidative metabolism was assessed by measuring O2- generation after stimulation with a soluble stimulant [phorbol myristate acetate (PMA), 1 mg/mL, Sigma Chemical, St. Louis, MO, U.S.A.] using the chemiluminescence method. Dialysate glucose effect on O2- generation was also studied in vitro by exposing peripheral PMNL and MNL from healthy controls to peritoneal dialysis fluid (PDF) containing glucose or amino acids at a neutral pH for different time periods.

RESULTS

The amount of O2- generation by both peripheral and peritoneal phagocytes in CAPD patients was significantly higher than that in the control, and the response was greater in patients who were dialyzed with high glucose dialysate than those using low glucose dialysate. In an in vitro study, all incubated cells, except the control, showed suppression of O2- generation in the early dwell time (2 hr), and subsequently showed increased responses (peaking at 6 hr), although lower in degree than those observed in vivo. In contrast, amino acid-based PDF exhibited no such effect on O2- generation at identical pH with similar or lower osmolality. Furthermore, the respective increased or decreased oxidative responses with the increased or decreased PDF glucose concentrations in the same patient confirmed the positive effect of PDF glucose on phagocyte O2- generation.

CONCLUSION

It is suggested that increased O2- generation by peritoneal and circulating phagocytes in CAPD patients is at least partly due to the enhancement of hexose monophosphate shunt activity by increasing glucose metabolism in phagocytes, and the increased O2- generation might be involved in long-term complications of CAPD. Therefore, a suitable alternative osmotic agent is needed to provide a more physiological environment to minimize the adverse effects of glucose on cell functions.

Prior brain injury protects death from local anaesthetic-induced convulsion

Minor brain injury was inflicted with a small hypodermic needle at four sites from the scalp 7 days before the production of convulsion by i.p. injection of 100 mg/kg lidocaine in mice. The latency to convulsion and survival rate were significantly longer and higher, respectively, in the brain-injured group than in the sham-operated one. Thus, the results suggest that a protective mechanism develops in the injured brain against asphyxia caused by lidocaine convulsion.

NMDA induces a biphasic change in intracellular pH in rat hippocampal slices

As alterations in intracellular pH (pH(i)) tend to exert a profound effect on the properties of cells, this study was undertaken to examine NMDA-induced changes in pH(i) in rat hippocampal slices using the BCECF fluorescent technique. The 'resting' pH(i) in the CA1 pyramidal cell layers was 6.93 +/- 0.07 (mean +/- S.D., n = 72 slices) in 25 mM HCO3-/5% CO2-buffered solution at 37 degrees C. Exposure of hippocampal slices to NMDA in the range of 10-1000 microM produced a biphasic change in pH(i): an initial transient alkaline shift was followed by a long-lasting acid shift. Dizocilpine (10 microM) but not CNQX (40 microM) blocked the NMDA-induced changes in pH(i). In 0 Ca medium (0 mM Ca2+ supplemented 1 mM EGTA, referred to as 0 Ca), pH(i) acid shift caused by NMDA (20 microM) declined by about 11%, whereas the initial alkaline shift almost completely disappeared. In an independent experiment, the NMDA-induced increase in intracellular Ca2+ ([Ca2+]i) was reduced by more than 80% in 0 Ca medium. Glucose substitution using equimolar pyruvate (as an energy-yielding substrate) suppressed this NMDA-induced pH(i) acid shift by two-thirds, while the NMDA-induced pH(i) alkaline shift was enhanced. Fluoride (10 mM), a glycolytic inhibitor, abolished NMDA-induced pH(i) acid shift. Furthermore, the lactate content of hippocampal slices was markedly increased following exposure to NMDA. In conclusion, activation of NMDA receptors in rat hippocampal slices evokes a biphasic change in pH(i). The initial alkaline shift is suggested to be associated with calcium influx, and the following acid shift may be caused by an increase in lactate production through the acceleration of glycolysis, as well as the increased [Ca2+]i. The pH(i) acid shift produced by the increased lactate may contribute to proton modulation of the NMDA receptor and NMDA-induced cell injury or death.

Rapid activation of MAP kinase by estrogen in the bone cell line

We examined the effect of estrogen on mitogen-activated protein kinase (MAPK) in osteoblastic cells. Rat ROS 17/2.8 cells were exposed to 17beta-estradiol (E2) and MAPK activity in the cells was measured by an in vitro phosphorylation assay. E2 treatment caused a rapid and transient MAPK activation within 5 min. Insulin-like growth factor-I, which acts via their membrane receptors, caused a similar effect, but it required 10 min to reach the maximum level. Western blot analyses with anti-MAPK and anti-phosphotyrosine antibodies demonstrated that the E2 activation of MAPK was accompanied by phosphorylation of the enzyme. The concentration range (10 nM-1 pM) of E2 needed for this MAPK activation was less than that (1 microM-0.1 nM) needed for the transcriptional activation via the nuclear estrogen receptor (ER). These data provide the first evidence of MAPK activation by E2 through phosphorylation, which may be mediated through a putative plasma membrane receptor in the cultured bone cells.

[Tc-99m labeled leukocyte scintigraphy and CT for the evaluation of patients with inflammatory bowel disease]

Seventeen cases (11 patients) of inflammatory bowel disease (IBD) were studied to define the intensity and extent of disease by 99mTc-HMPAO-labeled leukocytes scintigraphy (TLLS), and 10 cases underwent CT examination to evaluate the bowel wall, lymph-nodes, and mesenteric surroundings. Serial TLLS were obtained up to 4 hours and CT was carried out within one week before or after TLLS. The sensitivities of early (1 hour) and delayed (4 hours) TLLS were 91% and 100%, respectively. The respective specificities were 100% and 33%. However, it appeared that mild IBD may yield false negative results in early TLLS while non-specific bowel activity and migration of white cells may cause false positive results in delayed imaging. By setting the diagnostic criteria for labeled leukocyte accumulation on visualization of the small bowel regardless of uptake or activity of the large bowel similar to or greater than lumbar bone marrow, the sensitivity and specificity of delayed TLLS changed to 91% and 83%, respectively. On CT examination, mesenteric lymph-node swelling, periintestinal blurring and dilatation of mesenteric vasa recta were observed in all five patients with active Crohn's disease, while wall thickening and enhancement were seen in four of them. None of the other three cases of inflammatory disease showed positive findings of dilatation of the mesenteric vasa recta, and they revealed relatively low uptake of labeled leukocytes in TLLS. A "scintigram score" was calculated by comparing uptake of tracer in five bowel segments with lumbar bone marrow activity, and a "CT score" was calculated by adding abnormalities of the intestine and mesenteric surroundings. The scintigram score correlated closely with CT score and clinical disease activity. Combined use of CT and TLLS for the evaluation of patients with IBD was an excellent means to obtain the findings of intensity and extent of disease of the bowel wall and mesenteric surroundings and provided useful information in determining the patient management.

Three-dimensional structure of the rat pancreatic duct in normal and inflammated pancreas

We observed the corrosion casts of the Wistar rats' pancreatic ducts with scanning electron microscopy (SEM), and their conventionally fixed pancreatic tissue with SEM and transmission electron microscopy (TEM). These findings revealed the following facts about the three-dimensional structure of pancreatic duct. (1) The interlobular and intralobular ducts branch like a tree, and the intercalated ducts wind and fork into two branches, although parts of the intercalated ducts anastomose with each other. The intercellular secretory canaliculi extend from the central lumina, which run straight through the center of the acini, finally approaching close to the basement membranes of acini. (2) The lumina of pancreatic ducts (i.e., the interlobular up to the intercalated ducts) are cylindric and have smooth surfaces. The luminal surface of each epithelial cell, however, is decorated by numerous microvilli and a single cilium. The length of the latter tends to be short in proportion to the diameter of pancreatic duct. Moreover the epithelial cell surfaces, which border each central lumen, have various densities of microvilli. (3) The intraductal cilium core is provided with nine microtubules, which is different from the number of microtubules encountered within the cilium core of uterine tube or bronchial epithelium. The number of microtubules in the cross-sectioned intraductal cilia decreases toward the distal portion of cilia. SEM and TEM observations on WBN/Kob rats' pancreatic ducts suggest that increased pancreatic ductal pressure causes the helical shape of the pancreatic ductal lumen. Such a helical form might also be caused by the protrusion of epithelial cell boundaries into their lumen and the hypertrophy and hyperplasia of epithelial cells, thus leading to the formation of numerous depressions equipped with elongated cilia.

Assessment of clinical significance of positive blood cultures of relatively low-virulence isolates

In Omori Hospital, Toho University School of Medicine, relatively low-virulence blood isolates, including coagulase-negative staphylococci (CNS), enterococci and nonfermentative gram-negative rods other than Pseudomonas aeruginosa comprised c. 60% of total blood isolates. A retrospective study was conducted to assess their clinical significance by reviewing a total of 91 hospital charts. The physicians' assessments of these positive blood cultures as recorded in the charts were classified into four categories--sepsis, possible sepsis, contamination and no comment. The episodes classified as sepsis accounted for 5.0-19.6%. These episodes were also evaluated by a graded clinical significance score based on multiple factors, including number of positive cultures and clinical signs. The scores for the 91 episodes covered a wide range from 1 to 9, indicating that both contaminants and causative organisms may have been involved. The episodes judged as sepsis or possible sepsis tended to have higher scores. The scores for the episodes associated with enterococci were also higher than those involving CNS or non-fermentative gram-negative rods. The scores for episodes associated with intravenous hyperalimentation catheters were higher than those not associated with the catheters.

Central nuclei and spinal pathways in feedback inhibitory spinal cord potentials in ketamine-anaesthetized rats

It has been suggested that heterosegmentally activated slow positive potentials (HSP), recorded from the spinal cord of rat and humans, are feedback inhibitory potentials. The present study was carried out to define ascending and descending spinal tracts and the sites of central nuclei involved in the production of these HSP, and the effects of ketamine on these central nuclei. The spinal cords in ketamine-anaesthetized rats were transected to determine the ascending and descending tracts involved in the production of hindpaw (HP) and forepaw (FP) HSP, respectively. Lesions of the brain at various levels were performed stereotactically during ketamine anaesthesia. Dorsal one-third resection of the cord at the T8-9 level did not affect HSP significantly, while contralateral lesion of the dorsal two-thirds of the cord decreased FP-HSP but not HP-HSP during ketamine. Bilateral transection of the ventral one-third of the cord abolished both HSP. Ablation of the cerebral cortex, cerebellum, thalamus, midbrain and pons did not affect HSP significantly. However, transection of the middle medulla decreased, while transection of the most caudal part of the medulla completely abolished both HSP. Ketamine decreased HSP even in the medulla-spinal cord preparation and the segmental slow positive wave in spinalized animals. In ketamine-anaesthetized rats, ascending and descending spinal tracts involved in the production of HP-HSP and FP-HSP are located bilaterally in the ventrolateral quadrant and in the contralateral lateral funiculus and ventrolateral quadrant, respectively. Principal central nuclei feeding back HSP might be situated diffusely in the medulla down to the caudal part. Ketamine is suggested to suppress these inhibitory feedback potentials predominantly at, and partly even below, the level of the medulla.

Split posterior tibial tendon transfer for varus deformity of hindfoot

Sixteen patients (23 feet) who underwent split posterior tibial tendon transfers were evaluated. The patients were seen on a followup basis for a minimum of 1 year postoperatively. The causes were spastic cerebral palsy in 13 feet, spastic-athetoid cerebral palsy in 3 feet, hydrocephalus in 3 feet, and other diseases in 4 feet. The indication for surgery was varus deformity during the stance phase of gait and increased varus deformity during the swing phase of gait because of spasticity of the posterior tibial muscle. Heel cord lengthening was done on 17 feet. Preoperative and postoperative gaits were evaluated while the patients were walking. Axial radiographs of the calcaneus and the tibia were taken of all patients while they were weightbearing. There were 15 excellent, 6 good, and 2 poor results. The poor ratings were assigned to patients who had recurrence of varus deformity; there were no cases of overcorrection. Split posterior tibial tendon transfer was effective for treating spastic varus deformity of the hind part of the foot. This treatment also could be considered for a patient with spastic-athetoid cerebral palsy, if the deformity was determined to be caused by overactivity of the tibialis posterior muscle.

Activation of the estrogen receptor through phosphorylation by mitogen-activated protein kinase

The phosphorylation of the human estrogen receptor (ER) serine residue at position 118 is required for full activity of the ER activation function 1 (AF-1). This Ser118 is phosphorylated by mitogen-activated protein kinase (MAPK) in vitro and in cells treated with epidermal growth factor (EGF) and insulin-like growth factor (IGF) in vivo. Overexpression of MAPK kinase (MAPKK) or of the guanine nucleotide binding protein Ras, both of which activate MAPK, enhanced estrogen-induced and antiestrogen (tamoxifen)-induced transcriptional activity of wild-type ER, but not that of a mutant ER with an alanine in place of Ser118. Thus, the activity of the amino-terminal AF-1 of the ER is modulated by the phosphorylation of Ser118 through the Ras-MAPK cascade of the growth factor signaling pathways.

Fine structure of the cilia in the pancreatic duct of WBN/Kob rat

We observed the cilia in pancreatic ducts (intraductal cilia) with scanning and transmission electron microscopy (SEM and TEM), using male WBN/Kob rats (W/K), which are the spontaneously developed chronic pancreatitis models with stasis of pancreatic juice, and male Wistar rats as control. By SEM observations, the lengths of cilia in interlobular ducts of 18-mo-old W/K were demonstrated to elongate markedly. By TEM observations in the controls, cross-sections of the intraductal cilia were demonstrated to present various numbers of microtubules (those with seven, eight, or nine microtubules accounted for 83.3% of all). There was no significant difference between W/K and controls in the number of microtubules in the cross-sections of intraductal cilia: the intraductal cilium core was provided with nine microtubules, which were different from the number of microtubules encountered within the cilium core of other ciliated cell (i.e., bronchial epithelium, and so forth), and their number in the cross-section of intraductal cilium decreased at a distal portion. Though some of their cross-sections revealed deformities of ciliary membranes and disarrangements of microtubular complex, there was no significant difference in their incidence between both rats. These findings suggest that the intraductal cilia have different functions from the ciliated cells' cilia, and W/K has the elongated intraductal cilia without internal structural change.

Scanning electron microscopic observation of pancreatic ducts in WBN/Kob rats

To elucidate changes of pancreatic ducts in chronic pancreatitis, we observed pancreatic tissues with light microscopy and scanning electron microscopy, and corrosion casts of pancreatic ducts with scanning electron microscopy, in male WBN/Kob rats, considered a spontaneously occurring chronic pancreatitis model. At 3 months of age, hemorrhage and increased fibrosis were found in part of the pancreatic tail. After 3 months of age, pancreatic ductal lumina exhibited a winding form and inner surfaces showed long cilia and crater-like depressions. Fibrous tissues gradually extended into exocrine tissues and islets after 6 months of age. Most pancreatic ductal lumina developed a helical form with many deep depression at 14 months of age. It is suggested that increased pancreatic ductal pressure causes these findings.