Pathophysiology of dogs after 84% hepatectomy with emphasis on prostaglandin metabolites and the effect of a thromboxane A2 synthesis inhibitor and a prostaglandin I2 analog

The pathophysiological conditions following 84% hepatectomy were examined in terms of the changes in thromboxane A₂ (TxA₂) and prostaglandin I₂ (PGI₂) in canine model. OKY-046, TxA₂ inhibitor, and OP-2507, a PGI₂ analog, were administered to evaluate the possibility of extending hepatic resection. The 2-week survival rate following 84% hepatectomy significantly improved after the administration of OKY-046 and OP-2507, from 12.5% to 58.3% and 75.0%, respectively. Furthermore, OP-2507 significantly improved impaired hepatocyte and sinusoidal endothelial cell function after 84% hepatectomy, resulting in a satisfactory recovery to the preoperative levels. Within 24 h after 84% hepatectomy, the plasma levels of thromboxane B₂ (TxB₂) increased significantly, and the 6-keto-prostaglandin F_l (6-KF) levels became slightly elevated. OKY-046 and OP-2507 decreased TxB₂ and increased 6-KF in the plasma, resulting in the maintenance of sufficient blood flow in the portal vein and hepatic tissue and the mitigation of microcirculatory disorders. Moreover, the cytoprotective effects of the two drugs inhibited functional impairment of the residual liver. In conclusion, abnormal prostaglandin metabolites were produced after 84% hepatectomy, being involved in residual liver disorders. However, the administration of either an inhibitor of TxA₂ synthesis or PGI₂ analog ameliorated the functional impairment of the residual liver, which suggests their potential value for extending the resectability of the liver from what is presently feasible.An abstract of this study was presented at the 92nd Annual Meeting of the Japan Surgical Society held in 1992.     

Ocular manifestations of metabolic disorders

Articles published during the past year on the ocular manifestations of metabolic diseases and related issues are reviewed. The focus is on clarifying the genetic or molecular basis of various metabolic disorders. Mutations of the P gene were reported in tyrosinase-positive oculocutaneous albinism and autosomal recessive ocular albinism, and were associated with a wide range of clinical phenotypes. This finding should aid in more accurate diagnosis and facilitate genetic counseling. There is no consensus but the horizontal supranuclear gaze palsy in Gaucher's disease may aid in subtyping. The report of a family with Morquio syndrome suggests that lenticular opacities should be considered as an additional finding in this syndrome. Patients with nephropathic cystinosis, which had been a fatal disease in childhood, are now surviving to adulthood. Serious ocular complications were described in adults.     

Tocopherol Succinate Reference Standard (Control 981) of National Institute of Health Sciences

The raw material of tocopherol succinate was tested for preparation of the "Tocopherol Succinate Reference Standard (Control 981)". The analytical data obtained were: infrared spectrum same as that of the Tocopherol Succinate Reference Standard (Control 8510); specific absorbance, E(1%)1 cm (286 nm) = 40.7; thin-layer chromatography, no impurities detected until 50.0 microgram; high-performance liquid chromatography (HPLC),three impurities detected and amount of tocopherol succinate estimated to be 98.2%, loss on drying, 0.19%, assay by HPLC, 101.7%. Based on the above results, the raw material was authorized as the Japanese Pharmacopoeia Reference Standard (Control 981).     

Dermatofibrosarcoma protuberans harboring t(9;22)(q32;q12.2)

More than 20 cases of dermatofibrosarcoma protuberans (DFSP) exhibiting chromosomal abnormalities have been reported. Approximately three fourths of these tumors have harbored supernumerary ring chromosomes, which have been suggested to be specific for this tumor. However, a small number of DFSPs with translocations such as t(2;17), t(X;7), and t(17;22) have recently been reported. We report a DFSP arising in a 23-year-old woman which unexpectedly exhibited the balanced translocation, t(9;22)(q32;q12.2) as the only anomaly with G-band technique. Dual-color fluorescence in situ hybridization (FISH) confirmed these cytogenetic findings. Similar to that previously reported for DFSPs with translocations, the present tumor also lacked ring chromosomes.     

A novel mutation of CHRNA4 responsible for autosomal dominant nocturnal frontal lobe epilepsy

OBJECTIVE: To identify the mutation responsible for autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) in a nonwhite family. BACKGROUND: ADNFLE is newly recognized as an entity of idiopathic partial epilepsy. Recently, two different mutations of the neuronal nicotinic acetylcholine receptor alpha4 subunit (CHRNA4) gene were identified in a white family as a cause of ADNFLE. METHODS: Four affected and three unaffected individuals in three generations of a Japanese family with ADNFLE, and 100 unrelated healthy Japanese volunteers were studied. Clinical features and EEG findings in affected individuals were consistent with those of ADNFLE reported in white families with ADNFLE. Mutations within the CHRNA4 gene were screened for using single-strand conformation polymorphism analysis (SSCA) and were determined by direct sequencing. The mutation identified was sought in volunteers by the amplification refractory mutation system. RESULTS: A C-to-T exchange (C755T) was found in exon 5 of the CHRNA4 gene on one allele of affected individuals. C755T segregated in affected individuals and was not found in 200 alleles obtained from the volunteers. C755T replaced serine 252 (Ser252) in the second membrane-spanning domain (M2) of CHRNA4 with a leucine. Ser252 is conserved characteristically in the alpha-subunit of acetylcholine receptor and is considered to play an important role in channel function. CONCLUSION: C755T is a novel missense mutation of the CHRNA4 gene causing autosomal dominant nocturnal frontal lobe epilepsy in this Japanese family.     

Cholinergic-drug induced sicca syndrome in Parkinson's disease: a case report and a review of the literature

A 67-year-old woman developed severe sicca manifestations after initial treatment of Parkinson’s disease with an anti-cholinergic drug, which prompted us to look for the presence of Sjögren’s syndrome. The results of sialography, labial salivary gland biopsy, Rose–Bengal test as well as the presence of antinuclear antibody were consistent with the diagnosis of Sjögren’s syndrome. The sicca symptoms diminished by cessation of the anti-cholinergic drug, and the parkinsonian features were controlled by levodopa. We suggest that Sjögren’s syndrome should be considered, if patients with Parkinson’s disease complain severe xerostomia.     

In vitro and in vivo release properties of brilliant blue and tumour necrosis factor-alpha (TNF-alpha) from poly(D,L-lactic-co-glycolic acid) multiphase microspheres

The dissolution properties of two model compounds, brilliant blue and tumour necrosis factor (TNF-alpha), from poly(D,L-lactic-co-glycolic acid) (PLGA) multiphase microspheres were investigated. In addition, the in vivo release of TNF-alpha from the microspheres, in mice, was studied. The microspheres were prepared by an anhydrous multiple emulsion solvent evaporation method. Multiphase microspheres containing brilliant blue exhibited a three phase release profile in vitro, and displayed a significantly lower level of dye released during the initial phase compared to conventional matrix-type microspheres. Slow release of the dye was observed during the second phase, which was followed by a disintegration of the polymer wall during the third phase of the release process. In vitro dissolution profiles of TNF-alpha were calculated by compensation for the simultaneous degradation of the protein in the dissolution medium. The initial burst release of TNF-alpha was significantly reduced with the multiphase microspheres. The three phase release profile, as seen with the dye, was not observed for the microspheres containing the TNF-alpha. The rate of release of the protein from the microspheres was determined in vivo by analysing the residual level of TNF-alpha remaining in the particles following intraperitoneal administration of the microspheres to mice. The release of the protein from the microspheres in vivo was significantly faster than predicted from the results of the in vitro studies. The absence of an initial burst release of TNF-alpha from the multiphase microspheres was reflected in a significant reduction in the plasma level of TNF-alpha when compared to the matrix-type microspheres and a solution of the protein. The controlled release property of the multiphase microspheres is expected to overcome the adverse reactions due to dose dumping that occurs following the local administration of TNF-alpha.     

Hand-arm vibration syndrome and its prevalence in the present status of private forestry enterprises in Japan

Summary Currently there are no limitations on age of employment on private forestries in Japan. Hence, it was hypothesized that in these kind of enterprises, elderly chain saw operators, or those with long-term exposure, might be at higher risk of developing hand-arm vibration syndrome (HAVS). We consequently investigated the prevalence of HAVS in 447 chain saw workers on private forestries in Gifu Prefecture, Japan, with particular reference to age and exposure period. Of this population, 43 (9.6%) had signs and symptoms of vibration-induced white finger (VWF), and among these workers the severity of finger blanching was significantly correlated (P < 0.01) with the exposure period. Classification of all subjects by exposure period showed that workers with 30 years' exposure had higher prevalences of VWF (20.9%) and numbness of the hands (25.4%) compared to other groups. Significant differences (P < 0.01) were found between the functional capacities of workers with VWF and those of control subjects. We concluded that (a) the elderly chain saw operators and those with longer exposure should be moved to other jobs with a lower or no risk of exposure to vibration, and (b) the results of screening tests, even without cold water immersion (which we did not employ, in order to protect workers' hands), could be helpful for the identification of workers with VWF.     

Induction of active melanocytes in mouse skin by carcinogens: a new method for detection of skin carcinogens

Application of potent skin carcinogens, such as 7, 12-dimethylbenz[a]anthracene,3-methylcholanthrene, benzo[a]pyrene and 4-nitroquinoline-1-oxide,induced numerous dihydroxyphenylalanine (dopa)-positive cellsin the interfollicular epidermis of C57BL/6 mice in a dose-and time-dependent fashion. Chrysene, a weak skin carcinogen,and croton oil, a tumor promoter, also induced 3–4 timesmore dopa-positive cells than acetone. Liver carcinogens, suchas 3'-methyl-4-di-methylaminoazobenzene and N-2-acetylaminofluorene,and non-carcinogenic aromatic hydrocarbons, such as anthracene,fluoranthene, fluorene and pyrene, did not induce increase inthese cells. These results indicate that increase in the numberof dopa-positive cells after application of chemicals is wellcorrelated with the abilities of these compounds to induce skincarcino-genesis and suppress sebaceous glands.     

Current advances in rhinomanometry

Current advances in rhinomanometry were reviewed in this paper. Active posterior rhinomanometry with a “head-out” body plethysmograph may be the least invasive method currently available for measuring nasal patency. In general, active anterior rhinomanometry with a face mask or a nasal nozzle has been employed in various studies throughout the world. Nasal resistance as calculated from the equationR = 0.78 (ΔP/V)^1.33 at any points on a pressure/flow curve, or averaged nasal resistance may be the most suitable expression for nasal patency. Values for nasal resistance at ΔP 100 Pa in Japanese patients or ΔP 150 Pa in Caucasians have been widely employed as standard objective data for nasal obstruction, although rhinomanometric results sometimes do not agree with subjective evaluation of nasal obstruction. Nasal airflow acceleration or peak flow index during nasal breathing at rest can be applied as warranted to confirm an objective diagnosis of symptomatic nasal obstruction. Further, nationality and anthropological characteristics can be related to the severity and type of stuffiness.