Involvement of a Ca2+/calmodulin-dependent protein kinase II-associated mechanism in the induction of an outward potassium current by quisqualate

The inhibitory action of a glutamate agonist, quisqualate, in association with the intracellular signal transduction, was electrophysiologically examined in identified Euhadra neurons. Quisqualate dose-dependently induced a slow outward current (Quis current) which was blocked by tetraethylammonium. This current was suppressed by intracellular injection of Ca2+/calmodulin-dependent protein kinase II (CaMKII), and was enhanced by a CaMKII inhibitor, KN-62. However, no significant changes in the Quis current were observed when the catalytic subunit of protein kinase A (PKA) or the protein kinase C (PKC) fragment (530-558) was intracellularly applied; or using a PKA inhibitor, H-8, or a PKC inhibitor, staurosporine. These results suggest a novel mechanism linked to CaMKII, by which quisqualate induces an outward potassium current.

Amygdaloid kindling elicits persistent changes in pertussis toxin-catalyzed ADP-ribosylation

We examined the changes in pertussis toxin (PTX)-catalyzed ADP-ribosylation in amygdaloid-kindled rats to clarify the role of G proteins in the basic mechanisms of epilepsies. Autoradiographic analysis showed a remarkable increase in PTX-catalyzed ADP-ribosylation in 39-41-kDa proteins in hippocampus and cerebral cortex of kindled animals. The 39- to 41-kDa proteins were shown to be alpha-subunits of Gi and Go by immunoblotting with specific anti-Gi alpha and anti-Go alpha. The increase in ADP-ribosylation of these proteins was observed on stimulated and unstimulated sides of brains 24 h after the last generalized seizure and persisted for at least 3-4 weeks. These results suggest that persistent alterations in signal transduction through Gi and Go might be related to acquisition of long-lasting epileptogenesis.

Relationship between body composition and cardiorespiratory fitness in Japanese junior high school boys and girls

This study attempted to evaluate the influence of body composition on cardiorespiratory fitness as represented by maximal oxygen uptake (VO2max) in junior high school boys and girls. The subjects were judged apparently healthy. Measurements of VO2max during an incremental treadmill exercise testing as well as measurements of body composition were compared between obese boys and girls, 12 to 15 years old, and age- and height-matched nonobese boys and girls. Analyses of the data revealed that statistically significant (P < 0.01) mean differences between the obese and nonobese groups were observed for body mass (BM), percentage body fat, and body fat content. Fat-free mass (FFM) of obese boys was significantly larger than nonobese boys. There were significant differences between obese and nonobese groups irrespective of sex, when VO2max was expressed as milliliters of oxygen per kilogram of BM per minute. In contrast, no significant group differences were found in VO2max expressed as ml per kg of FFM per min. No significant differences existed either for absolute VO2max between the obese girls and the nonobese girls due almost entirely to the similarity in FFM between these two groups. Significant correlations were found both in boys (r = -0.742) and girls (r = -0.843) between VO2max (ml/kg BM/min) and percentage body fat, thereby indicating the striking effects of excess body fat. These results in the present study support the general belief that obesity accentuates exercise intolerance and low aerobic capacity.

Transient expression of type II collagen and tissue mobilization during development of the scleral ossicle, a membranous bone, in the chick embryo

Development of the chick scleral ossicle was studied with respect to expression of various collagen types, cartilage matrix molecules, and osteoblastic cell surface antigens. The extra-cellular matrix of the scleral ossicle primordium of stage 35.5 chick sclera and the mesenchyme beneath the conjunctival epithelium was immunoreactive with anti-type II collagen antibody, giving the impression that certain materials and/or cell clusters surrounded by reactive matrix were descending from the epithelial-mesenchymal interface to the scleral ossicle primordium. In stage 37 embryos, type II collagen immunoreactivity was restricted to the bone matrix of the scleral ossicles, and persisted through stage 39. However, at stage 41, virtually no type II collagen was detected. In contrast, strong immunostaining of type I collagen was first detected in the developing scleral ossicle at stage 37, coinciding with the formation of mineralized bone matrix. Following the extensive accumulation of type I collagen in bone matrix, type XII collagen was detected at the surface of the bone; both type I and type XII collagen immunostainings then remained. By stage 37, immunoreactivity with a pre-osteoblastic cell surface marker was detected on cells of the scleral ossicle, and typical osteocytes were subsequently identified by both morphological and specific immunostaining techniques. Antibodies other than for type II collagen, specific to chondrogenic mesenchyme or cartilage matrix, never reacted with the scleral ossicle and its primordium during development. Taken together, these observations indicate that the scleral ossicle is a membranous bone, whose development may not require overt chondrogenesis. Implications of type II collagen distribution during the positioning of scleral ossicles and their early bone matrix formation are discussed with respect to the origin and evolution of endoskeletons in vertebrate animals.

Focal spasms in clusters, focal delayed myelination, and hypsarrhythmia: unusual variant of West syndrome

We report a patient who began to have clusters of seizures characterized by brief elevation of the right arm at 6 months of age. An interictal electroencephalogram (EEG) at 7 months revealed hypsarrhythmia without definite asymmetry. Simultaneous EEG and video recording disclosed that these focal spasms were associated with fast wave bursts superimposed on slow waves most markedly in the left centro-midtemporal region. The patient became seizure-free after synthetic ACTH therapy. The patient is developmentally normal at 3 years 5 months, but magnetic resonance imaging studies revealed findings suggestive of delayed myelination in the left frontal region. This patient is considered to have had an unusual variant of West syndrome associated with focal delayed myelination.

[JCCLS proposal for clinical allowance on values of blood cell count]

We investigated the clinically allowable error for laboratory quality control of blood cell count in Japan. We have asked 409 members of Japanese Association of Clinical Hematology for an appropriate clinical allowance on the values of red blood cell count (RBC), hemoglobin value (Hb), mean corpuscular volume (MCV), white blood cell count (WBC) and platelet count (PLT). We delivered the lists in which 5 different allowable errors (2, 3, 5, 10 and 20%) were indicated on each blood cell count so that each member could check one of them. The data were collected within a month and were analyzed with computer. The results showed that 312 (76.3%) members choose 3 or 5% as an allowable error for RBC, 393 (96.1%) selected 2, 3 or 5% for Hb, 314 (76.8%) choose 3 or 5% for MCV, 358 (77.5%) indicated 3, 5 or 10% for WBC and 294 (72.6%) selected 5 or 10% for PLT. Based on these data, we propose the following clinical allowances for the values of blood cell count; 4% for RBC, 3% for Hb, 4% for MCV, 5% for WBC and 7% for PLT.

Rapid improvement of coagulopathy by all-trans retinoic acid in acute promyelocytic leukemia

Treatment of acute promyelocytic leukemia (APL) patients with all-trans retinoic acid (ATRA) was associated with rapid improvement in hemostatic markers. We made serial analyses of various hemostatic parameters in seven newly diagnosed APL patients. In all patients at diagnosis, plasma fibrinogen/fibrin degradation product (fragment-E), cross-linked fibrin degradation product (D-dimer fragment), thrombin-antithrombin III complex and plasmin-alpha 2-plasmin inhibitor complex were elevated, indicating the presence of disseminated intravascular coagulation (DIC). Antithrombin III (ATIII) levels were normal in all patients except for the patient with congenital ATIII deficiency. In four patients subsequently treated with ATRA without anticoagulant therapy, these hemostatic markers returned to near-normal levels by day 7 of treatment, indicating that DIC was essentially resolved. By contrast, in three patients who received conventional chemotherapy with a continuous low-dose heparin, improvement of coagulopathy was slower than in patients treated with ATRA. These results suggest that ATRA therapy exerts the rapid improvement in abnormal hemostatic markers in APL patients without any anticoagulant therapies, by inducing differentiation of leukemic cells and, in turns no massive release of procoagulant or fibrinolytic substances from these cells.

Pseudolipoma of Glisson's capsule. Report of six cases and review of the literature

We report six cases of pseudolipoma of Glisson's capsule. The patients ranged from 53 to 83 years old (mean 67.7 years), and all were men. Pseudolipoma of Glisson's capsule was detected by imaging studies before operation in two cases, and noted incidentally in the remaining four. Computed tomography demonstrated a subcapsular low-density nodule with or without a high-density spot. All but one patient had a history of abdominal operation. Grossly, the pseudolipoma was a solitary encapsulated nodule on the surface of the anterior aspect in five, and posteroinferior to the right lobe in one. The pseudolipomas ranged from 0.5 to 2 cm in diameter, were white to yellowish-white and elastic-firm. Histologically, the nodules had a dense fibrous capsule and contained necrotic mature fat tissue. In addition, three showed focal calcification. Blood vessels were rarely found within the capsule. These findings strongly suggest that history of abdominal operation, advanced age, sex, and poor blood supply to the nodule are causal to their development. Although only 18 cases have been reported previously, our six cases during but a 3-year period suggests that it may not be as rare as believed.

[The prognostic value of neonatal cranial ultrasonography in infants with periventricular leukomalacia]

Serial cranial ultrasonography was performed in 17 preterm infants with periventricular leukomalacia (PVL) in the neonatal period. Periventricular high-echogenicities were observed in all infants, and periventricular cysts in 14/17 infants (82%). We investigated the correlation between these findings and abnormalities on MRI in late infancy. Periventricular high-echogenicity was correlated with the extent of periventricular high-intensities on T2-weighted images of late infantile MRI. The extent of periventricular cysts was correlated with that of volume loss on MRI during late infancy. The degree of periventricular echo-lesion was associated with that of neurological abnormalities of infants. The extent of periventricular echo-lesion has the same prognostic value as findings on MRI in infants with PVL.

[Statistical study of aqueous flare in rhegmatogenous retinal detachment]

Inflammation of the anterior chamber in rhegmatogenous retinal detachment was studied in 338 eyes with a laser flare cell meter. The mean flare value, 32.84 +/- 81.39 pc/msec, was significantly higher (p < 0.0001) than the 5.01 +/- 2.05 pc/msec of the control group of 133 normal eyes. Clinical findings of retinal detachment were grouped into 11 factors and each factor was divided into 34 details. The following details were proven by t-test to cause significant elevation of the flare value: (1) duration of more than 3 months, (2) hypotony of less than 9 mmHg, (3) aphakia, (4) retinal breaks in the ora area or the posterior area, (5) extension of retinal detachment with more than 2 quadrants, and (6) choroidal detachment. The correlation coefficients of the 6 clinical factors showed significant elevation of flare value in the following order: (1) presence or absence of choroidal detachment (0.396), (2) extension of retinal detachment (0.375), (3) intraocular pressure (-0.28), (4) duration of retinal detachment (0.18), (5) location of the break (0.15), and (6) presence or absence of the lens (0.134).

Fat-free mass in Japanese boys predicted from bioelectrical impedance and anthropometric variables

OBJECTIVE

To develop the best prediction equation for estimating fat-free mass (FFM) from bioelectrical impedance and anthropometric variables in Japanese boys.

SUBJECTS

141 boys, aged 9-14 years, were recruited from elementary schools managed by Osaka City.

METHODS

FFM was calculated from underwater weighting (UW) using a two-component model. Prediction equations were developed using multiple regression analyses. Adjusted R2 and standard errors of the estimate (SEE) ranged from 0.831 to 0.854 and from 1.25 to 1.80 kg in the validation group (n = 84), and ranged from 0.817 to 0.912 and from 1.27 to 1.86 kg in the cross-validation group (n = 57), respectively. The validation group and cross-validation group were combined in order to develop a more stable prediction equation with a greater sample size (n = 141).

RESULTS

The variables ZI (height2/impedance), body mass (M) and abdominal skinfold thickness were found to be the best combination of predictors. Adjusted R2 and SEE for finally developed regression equations ranged from 0.949 to 0.975 and from 1.50 to 2.10 kg.

CONCLUSION

As a result of all analyses and considering the practicability of the measurement, we recommend the equation FFM = 0.56ZI+0.20M+1.66, with an adjusted R2 of 0.971 and SEE of 1.59 kg, which can predict FFM with high precision in Japanese boys.

Prosopagnosia without topographagnosia and object agnosia associated with a lesion confined to the right occipitotemporal region

A patient is presented who developed prosopagnosia with a recent occipitotemporal infarct in the distribution of the right posterior cerebral artery. He did not have topographical agnosia or object agnosia. He regained the ability to recognize faces of familiar persons, whereas he remained unable to identify faces of persons whom he met after the disease onset. This case demonstrates that prosopagnosia may occur as a deficit of matching a perceived face to a memory store of the face, and that the failure to recognize unfamiliar faces may be due to the inability to form memory stores of new faces. These deficits can occur in association with a lesion confined to the right occipitotemporal region.

Permeability for horseradish peroxidase in strial capillaries in each turn of cochlea

The capillary permeability of the stria vascularis in each turn of cochlea was examined at intervals of 10 and 30 min and 1 and 2 h after an injection of horseradish peroxidase (HRP), using light and electron microscopic techniques. Ten minutes after HRP was administered, 18% of examined vessels showed HRP leakage. Thereafter, the level of HRP leakage increased with time. One hour after the injection, HRP had leaked from almost all vessels of the upper three turns. Two hours after the injection, the tracer in the vessel lumen became sparse with very thin staining or nonstaining, and a large amount of HRP was observed outside the vessels. It was noted that the capillary permeability to HRP at the basal turn was different from that of the upper three turns. This seems to be the result of the different pinocytic activity in the capillaries of these two regions. When the tracer disappeared from the vessels (2 h after the HRP injection), labelled vesicles in endothelial cells were frequently visible near the outside surface, whereas very few were visible near the inner surface. It is speculated, therefore, that HRP which has leaked can be reabsorbed back into the blood circulation via a similar micropinocytosis down the concentration gradient.

Nuclease resistance of an extraordinarily thermostable mini-hairpin DNA fragment, d(GCGAAGC) and its application to in vitro protein synthesis

The nuclease resistance of a short, thermostable mini-hairpin, d(GCGAAGC), and other related hairpins was examined. Hairpins possessing a purine-rich (GAA) or (GAAA) loop appeared to be more resistant against nucleases than those with a pyrimidine-rich loop or single-stranded oligomers. Among 8 kinds of oligodeoxyribonucleotides examined, the fragment most resistant against nucleases was a hairpin with the sequence of d(CGCGAAGCG). This hairpin was then utilized for the stabilization of mRNA in an in vitro translation system; the 3'-terminal region of an mRNA was hybridized with an oligodeoxyribonucleotide including the sequence complementary to the 3'-terminus of the mRNA tagged with the nuclease-resistant d(CGCGAAGCG) hairpin sequence. By using this method, dihydrofolate reductase (DHFR) mRNA was stabilized against nucleases contaminating a cell-free translation system of E.coli, with a consequent increase in protein synthesis efficiency of 200%.

Evolutional changes of cortical hypometabolism in West's syndrome

The pathophysiological basis of the epileptic encephalopathy West's syndrome remains unknown. We have done serial positron emission tomography (PET) with fluorine-18-labelled 2-deoxy-3-fluoro-D-glucose (FDG) in twelve patients with newly diagnosed West's syndrome. Throughout follow-up, PET revealed diffuse or focal cortical hypometabolism in eleven patients, whereas magnetic resonance imaging (MRI) showed morphological abnormalities in only five. At disease onset, PET showed cortical hypometabolism in eight patients (diffuse in three, focal in five). The second PET showed normal metabolism in six of these patients but focal abnormalities in three of the four with normal results on first PET. In all seven patients with normal findings on the second PET, tonic spasms ceased after initial treatment and no epileptic seizure occurred thereafter. In the five patients with cortical hypometabolism on the second PET, tonic spasms persisted or recurred, or partial seizures appeared. However, in two patients PET abnormalities disappeared in accordance with the later resolution of epileptic seizures. All patients with normal MRI and second PET results had normal psychomotor development. Diffuse or focal cortical hypometabolism that cannot be detected by MRI or computed tomography is common in patients with West's syndrome. However, this anomaly is not permanent and changes with clinical symptoms. These functional abnormalities in the cerebral cortex may be associated with the development of West's syndrome.

Effect of the order of antibody variable regions on the expression of the single-chain HyHEL10 Fv fragment in E. coli and the thermodynamic analysis of its antigen-binding properties

In order to physically stabilize the Fv fragment of anti-lysozyme monoclonal antibody, HyHEL10, the variable domains were linked covalently with a flexible linker. A marked difference in the level of expression in E. coli was observed between VH-linker-VL (scFvHL) and VL-linker-VH (scFvLH). The highly expressed scFvLH was purified by a single step of affinity chromatography from the culture supernatant with a typical yield of 3-5 mg per liter of culture. This HyHEL10 scFvLH showed reduced binding activity toward its antigen, HEL, in comparison with Fv. Thermodynamic study showed that this reduced activity was due to entropic loss upon binding to its antigen, although this interaction between scFvLH and its antigen was enthalpically favorable.

Retinal detachment with atopic dermatitis similar to traumatic retinal detachment

PURPOSE

The cause of retinal detachment (RD) with atopic dermatitis remains uncertain. The purpose of this study is to show that the probable cause of RD with atopic dermatitis is ocular contusion.

METHODS

The authors retrospectively compared the fundus findings of 24 eyes (16 patients) that had RD and atopic dermatitis with 36 eyes (36 patients) that had traumatic RD.

RESULTS

The authors found similar characteristics. Retinal breaks at vitreous base borders characterized by ocular contusion occurred in 79.2% of eyes with RD and atopic dermatitis and in 75.0% of eyes with traumatic RD. Irregular retinal traumatic breaks in the equatorial zone occurred in 20.8% of eyes with RD and atopic dermatitis and in 47.2% of eyes with traumatic RD. Objective signs of ocular contusion outside the retina appeared in 54.2% of eyes with RD and atopic dermatitis.

CONCLUSIONS

The authors' data support the conclusion that self-inflected ocular contusion by tapping the eyes can cause RD with atopic dermatitis.

An experience of ischemic limb salvage associated with myositis ossificans of the left thigh

A case of ischemic limb salvage associated with myositis ossificans of the left thigh in a 66-year-old man was reported. The patient had a medical history of cerebral palsy and a cervical spinal cord injury, and had an operative past history of hip arthroplasty for fracture of the left femoral neck 10 years before. He showed ischemic symptoms such as paleness, coldness, and loss of the left dorsal arterial pulsation in the left toe, and had a rapidly growing mass in the left thigh. Roentgenography and computed tomography showed a mass 10 cm by 10 cm by 8 cm in size with severe calcification in the left quariceps muscle. Occlusion of the left common femoral artery was found in the arteriogram. Surgery was carried out in order to establish an accurate diagnosis and to rescue the left lower limb. The arterial pulsation was recovered as the result of completely resecting the left quariceps muscle tumor. The pathohistological diagnosis was of myositis ossificans in the quariceps muscle of the thigh. Etidronate disodium was administered in order to prevent a recurrence postoperatively. The patient has been well for the 13 months since surgery.

Fusarium merismoides Corda NR 6356, the source of the protein kinase C inhibitor, azepinostatin. Taxonomy, yield improvement, fermentation and biological activity

Fungal strain NR 6356, Fusarium merismoides Corda, was discovered as the source of the protein kinase C (PKC) inhibitor, azepinostatin. The strain was identified based on its growth on potato sucrose agar, slender conidial shape, characteristic polyphialide and production of abundant chlamydospores. Fusarium aquaeductuum Lagh. IMI 103658 and Fusarium sp. NR 7222 were also found to produce the same inhibitor. After single colony isolation and medium optimization trials, a more than 30-fold increase in the production of azepinostatin over the original culture was achieved. Azepinostatin selectively and potently inhibited rat brain PKC with an IC50 value of 70 nM. Other enzymes utilizing ATP, including hexokinase, were not affected. The Ki of azepinostatin for PKC was 0.5 nM. The inhibition of PKC was competitive with ATP and uncompetitive with histone.

Acceleration of diabetes in young NOD mice with peritoneal macrophages

To elucidate the roles of macrophages in the pathogenesis of NOD murine diabetes, peritoneal macrophages from NOD mice were injected into young NOD mice. We used 12 to 20 week-old NOD mice of both sexes as donors, and sex-matched 2-week-old NOD mice as recipients. Cyclophosphamide (CY), 200 mg/kg, was intraperitoneally injected into the donors. Two weeks later, peritoneal exudate cells (PEC) were collected from the diabetic donors. Macrophage-rich fractions (MRF) were collected by adherence. Then PEC(5-8 x 10(6)) or MRF(3-7 x 10(6)) were transferred, intraperitoneally, to the recipients. Two weeks later, some of the recipients were killed in order to perform immunofluorescent analysis of splenocytes and to assess pancreatic histology. Mac 1 positive splenocytes were increased in PEC- and in MRF-injected recipient mice. Insulitis was seen in PEC- and MRF-injected mice, but not in controls. Some of the recipients were injected with CY, 200 mg/kg, intraperitoneally, at two weeks post cell transfer. Two weeks after CY injection, the animals were examined for the presence of diabetes. The incidences of diabetes were 67% in PEC-injected mice, 40% in the MRF-injected group, and 3% in the controls. These results suggest that peritoneal macrophages accelerate the disease process in NOD mice.

Antiepileptic drugs--calcium current interaction in cultured human neuroblastoma cells

The voltage-dependent calcium channel current (ICa) in the neuroblastoma cell line of human origin (NB-I) was studied by the whole-cell clamp recording. Three types of ICa were identified in NB-I cells. Our electrophysiological and pharmacological findings have suggested that these three types of ICa are consistent with the T-, N- and L-type ICa, respectively. Phenytoin (PHT) inhibited T-type ICa by 13.0% at a concentration of 5 microM, and L-type ICa by 6.3% at a concentration of 100 microM. At a concentration of 100 microM, carbamazepine (CBZ) inhibited T- and L-type ICa by 6.0% and 5.9%, respectively. At a concentration of 50 microM, sodium valproate (VPA) blocked T- and L-type ICa by 6.1% and 47.5%, respectively. At a concentration of 50 microM, zomisamide (ZNS) inhibited T- and L-type ICa by 38.3% and 41.9%, respectively. Na+ channel blockade has been reported to be responsible for the clinical efficacy of PHT or CBZ. Inhibition of T-type ICa by PHT may enhance the efficacy of its anticonvulsant action. CBZ had little effect on ICa. The anticonvulsant activity may be related to the blockade of T-type ICa in the case of VPA and ZNS.

Frequent expression of 75 kDa nerve growth factor receptor and phosphotyrosine in human peripheral nerve tumours: an immunohistochemical study on paraffin-embedded tissues

One hundred and three benign, and 10 malignant peripheral nerve tumours were examined immunohistochemically for expression of 75 kDa nerve growth factor receptor (NGFR). In benign tumours NGFR was demonstrated at 61% in neurinoma, 71% in neurofibroma, 93% in neurofibromatosis and 90% in traumatic neuroma. Malignant neurogenic tumours were 100% positive for NGFR. Phosphotyrosine-immunoreactivity was detected in 76% of NGFR-positive tumours but the frequency of immunostained tumour cells was low. These results suggest that both benign and malignant peripheral nerve tumours express 75 kDa NGFR. The receptor seems to serve as growth signal transduction of the tumour cells in terms of phosphorylation of the tyrosine residue of the receptor or the target protein of the NGFR protein tyrosine kinase.

Predominant melanogenesis and lentoidogenesis in vitro from multipotent pineal cells by dimethyl sulfoxide and hexamethylene bisacetamide

Pineal cells of the 8-day embryonic quail are multipotent cells which differentiate in vitro into skeletal muscle fibers, pigmented epithelial cells (PECs), lens cells and neurons. However, it was not yet clear whether precursor cells which gave such a wide repertoire of differentiation were single type or not. The present culture studies revealed that pineal cells were exclusively directed to ocular differentiation pathways by dimethyl sulfoxide (DMSO) and hexamethylene bisacetamide (HMBA), suggesting a single type of precursor cell in the pineal body. DMSO directed pineal cells to differentiate into PECs. Co-administration of basic fibroblast growth factor (bFGF) with DMSO partially inhibited PEC differentiation and promoted lens cell differentiation. Northern blot analysis using cDNAs specific to PEC and lens cell confirmed this morphological observation. HMBA completely inhibited pigmentation of cultured pineal cells and markedly promoted lens cell differentiation. Ocular differentiation of pineal cells was accompanied with the loss of myogenicity. We discuss three possible pathways of lens cell differentiation from pineal cells. The agents which affect pineal cell differentiation seemed to modulate the cell-substrate interaction. And the interaction was suggested to be one of the environmental cues in the differentiation.