Leigh-like syndrome with progressive cerebellar atrophy caused by novel HIBCH variants

Pathogenic variants in the HIBCH gene cause HIBCH deficiency, leading to mitochondrial disorders associated with valine metabolism. Patients typically present with symptoms such as developmental regression/delay, encephalopathy, hypotonia and dystonia. Brain magnetic resonance imaging (MRI) shows bilateral lesions in the basal ganglia with/without brainstem involvement. Here, we report a case of a Japanese patient with Leigh-like syndrome caused by novel HIBCH variants. Long-term follow-up MRI revealed progressive cerebellar atrophy, which expands the phenotypic spectrum of HIBCH deficiency.

Myosin Va, a novel interaction partner of STXBP1, is required to transport Syntaxin1A to the plasma membrane

Syntaxin-binding protein 1 (STXBP1, also known as Munc18-1) regulates exocytosis as a chaperone protein of Syntaxin1A. The haploinsufficiency of STXBP1 causes early infantile-onset developmental and epileptic encephalopathy, known as STXBP1 encephalopathy. Previously, we reported impaired cellular localization of Syntaxin1A in induced pluripotent stem cell-derived neurons from an STXBP1 encephalopathy patient harboring a nonsense mutation. However, the molecular mechanism of abnormal Syntaxin1A localization in the haploinsufficiency of STXBP1 remains unknown. This study aimed to identify the novel interacting partner of STXBP1 involved in transporting Syntaxin1A to the plasma membrane. Affinity purification coupled with mass spectrometry analysis identified a motor protein Myosin Va as a potential binding partner of STXBP1. Co-immunoprecipitation analysis of the synaptosomal fraction from the mouse and tag-fused recombinant proteins revealed that the STXBP1 short splice variant (STXBP1S) interacted with Myosin Va in addition to Syntaxin1A. These proteins colocalized at the tip of the growth cone and axons in primary cultured hippocampal neurons. Furthermore, RNAi-mediated gene silencing in Neuro2a cells showed that STXBP1 and Myosin Va were required for membrane trafficking of Syntaxin1A. In conclusion, this study proposes a potential role of STXBP1 in the trafficking of the presynaptic protein Syntaxin1A to the plasma membrane in conjunction with Myosin Va.

Identification of RCC1-LCK as a novel fusion gene in pediatric erythroid sarcoma

Erythroid sarcoma is a very rare subtype of myeloid sarcoma with undetermined biological features. Here, we present an infant with a multifocal erythroid sarcoma, diagnosed because the tumor cells were positive for glycophorin A. After acute myeloid leukemia-oriented chemotherapy and surgical resection followed by cord blood transplantation, he has successfully maintained complete remission without any late effects. Total transcriptome analysis of the tumor identified a novel fusion gene, RCC1-LCK, and high LCK expression levels, suggesting that LCK overexpression was involved in leukemogenesis in this case.

Impaired neuronal activity and differential gene expression in STXBP1 encephalopathy patient iPSC-derived GABAergic neurons

Syntaxin-binding protein 1 (STXBP1; also called MUNC18-1), encoded by STXBP1, is an essential component of the molecular machinery that controls synaptic vesicle docking and fusion. De novo pathogenic variants of STXBP1 cause a complex set of neurological disturbances, namely STXBP1 encephalopathy (STXBP1-E) that includes epilepsy, neurodevelopmental disorders and neurodegeneration. Several animal studies have suggested the contribution of GABAergic dysfunction in STXBP1-E pathogenesis. However, the pathophysiological changes in GABAergic neurons of these patients are still poorly understood. Here, we exclusively generated GABAergic neurons from STXBP1-E patient-derived induced pluripotent stem cells (iPSCs) by transient expression of the transcription factors ASCL1 and DLX2. We also generated CRISPR/Cas9-edited isogenic iPSC-derived GABAergic (iPSC GABA) neurons as controls. We demonstrated that the reduction in STXBP1 protein levels in patient-derived iPSC GABA neurons was slight (approximately 20%) compared to the control neurons, despite a 50% reduction in STXBP1 mRNA levels. Using a microelectrode array-based assay, we found that patient-derived iPSC GABA neurons exhibited dysfunctional maturation with reduced numbers of spontaneous spikes and bursts. These findings reinforce the idea that GABAergic dysfunction is a crucial contributor to STXBP1-E pathogenesis. Moreover, gene expression analysis revealed specific dysregulation of genes previously implicated in epilepsy, neurodevelopment and neurodegeneration in patient-derived iPSC GABA neurons, namely KCNH1, KCNH5, CNN3, RASGRF1, SEMA3A, SIAH3 and INPP5F. Thus, our study provides new insights for understanding the biological processes underlying the widespread neuropathological features of STXBP1-E.

Complex hereditary spastic paraplegia associated with episodic visual loss caused by ACO2 variants

Most patients with homozygous or compound heterozygous pathogenic ACO2 variants present with muscular hypotonia features, namely, infantile cerebellar-retinal degeneration. Recently, two studies reported rare familial cases of ACO2 variants presenting as complex hereditary spastic paraplegia (HSP) with broad clinical spectra. Here, we report the case of a 20-year-old Japanese woman with complex HSP caused by compound heterozygous ACO2 variants, revealing a new phenotype of episodic visual loss during febrile illness.

Human lung microvascular endothelial cells as potential alternatives to human umbilical vein endothelial cells in bio-3D-printed trachea-like structures

BACKGROUND

We have been trying to produce scaffold-free structures for airway regeneration using a bio-3D-printer with spheroids, to avoid scaffold-associated risks such as infection. Previous studies have shown that human umbilical vein endothelial cells (HUVECs) play an important role in such structures, but HUVECs cannot be isolated from adult humans. The aim of this study was to identify alternatives to HUVECs for use in scaffold-free structures.

METHODS

Three types of structure were compared, made of chondrocytes and mesenchymal stem cells with HUVECs, human lung microvascular endothelial cells (HMVEC-Ls), and induced pluripotent stem cell (iPSC)-derived endothelial cells.

RESULTS

No significant difference in tensile strength was observed between the three groups. Histologically, some small capillary-like tube formations comprising CD31-positive cells were observed in all groups. The number and diameters of such formations were significantly lower in the iPSC-derived endothelial cell group than in other groups. Glycosaminoglycan content was significantly lower in the iPSC-derived endothelial cell group than in the HUVEC group, while no significant difference was observed between the HUVEC and HMVEC-L groups.

CONCLUSIONS

HMVEC-Ls can replace HUVECs as a cell source for scaffold-free trachea-like structures. However, some limitations were associated with iPSC-derived endothelial cells.

Transcatheter arterial embolisation in four dogs with hepatocellular carcinoma

Four dogs with hepatocellular carcinoma were treated by transcatheter arterial embolisation. In all dogs, the tumour-supplying arteries were selectively embolised with gelatine sponge particles. Post-embolisation tumour volumes decreased relative to pre-embolisation volumes in all dogs. No adverse reactions were observed in three dogs after treatment but one dog showed pancreatitis. These results suggest that transcatheter arterial embolisation is a feasible treatment for dogs with hepatocellular carcinoma.

Assessment of canine ovaries autografted to various body sites

The influence of graft site on the survival of canine follicles and oocytes after autografting was investigated. Hemi-ovaries were autografted to three locations (quadriceps femoris muscle fascia, kidney capsule, and gastrosplenic ligament), and grafted ovaries were recovered (under anesthesia) 28 to 31 d after transplantation. The grafted hemi-ovaries were bisected: one-quarter ovary was used for histological assessment and another quarter for evaluation of oocyte viability. As controls, the remaining fresh hemi-ovaries were used to assess the viability of follicles and oocytes in non-transplanted ovaries. Most follicles in the histological sections of the grafts were classified as primordial or primary follicles. Antral follicles were not observed in the grafts, irrespective of the graft site. The percentages of viable follicles in the sections from control ovaries, and the ovaries grafted to the kidney capsule, the quadriceps femoris muscle fascia, and the gastrosplenic ligament were 17.4, 22.9, 18.3, and 32.4%, respectively. A total of 12 oocytes was recovered from the 15 hemi-ovaries grafted in five bitches, of which five (41.7%) oocytes from the ovaries grafted to the quadriceps femoris muscle fascia and the kidney capsule were cultured for assessment of meiotic competence. Three oocytes were viable but remained in the germinal vesicle stage after 72 h of maturation culture. The quadriceps femoris muscle fascia might be useful for grafting like the kidney capsule, but improvement of follicle survival and meiotic competence of oocytes in the grafts is necessary.

Quantitative investigation and classification by MRI of residual cleft cysts in the pituitary glands of cows

The application of MRI to 167 Holstein cows and 76 Japanese black cows made it possible to distinguish two types of residual cleft cysts (RCCs) in their pituitary glands on the basis of the differences in signal intensity: fluid-filled lesions with an intensity equal to that of cerebrospinal fluid (CSF) (hypointense on T1-weighted images and hyperintense on T2-weighted images); and solid lesions that were hypointense compared with cerebral parenchyma and isointense with CSF on T1-weighted images, and hypointense compared with cerebral parenchyma on T2-weighted images. Solid material was observed in lesions with a mean (sd) diameter of 2.09 (1.28) mm in 56 (33.5 per cent) of the Holstein cows, and in lesions with a mean diameter of 1.91 (0.89) mm in 20 (26.3 per cent) of the Japanese black cows. Four of the Holstein cows had RCCs more than 7 mm in diameter. Long-term development of the RCCs was suggested by histological findings of epithelial stratification and a structural shift from having a single to a stratified epithelial layer within the residual clefts of the affected pituitary glands.

[Bronchial schwannoma diagnosis by surgical treatment; report of a case]

18-year-old male was referred to our hospital due to persistent cough. The patient was admitted for the investigation of the abnormal shadow on a chest X-ray and chest computed tomography (CT). Chest CT showed a 2.5 cm nodular shadow in the right lower lobe. Bronchofiberscopy revealed the polypoid lesion at the right lower lobe bronchus obstructing the entire lumen of B8-10. The tumor surface was smooth and rich in small vessels. Right lower lobectomy was peformed. The diagnosis of schwannoma was confirmd with the S-100 positive immunohistochemical stain. Bronchial schwannoma is relatively rare disease; less than 90 cases have been reported with respect to schwannoma of case report in Japan.

Protein expression of Mdm2 and p53 in hyperplastic and neoplastic lesions of the canine circumanal gland

Hyperplastic and neoplastic lesions of the circumanal gland in dogs were examined immunohistochemically for nuclear expression of Mdm2 and p53 proteins. Mdm2 nuclear labelling was detected in 64.3% of hyperplastic lesions and 70.7% of adenomas, the immunolabelling being stronger in the latter. Mdm2 reactivity in reserve-like cells in adenomas showed wide variation, the immunoreactive cells ranging from 4 to 80%. No reactivity was shown in 81.9% of adenocarcinomas. In contrast to Mdm2 reactivity, each of 14 hyperplastic lesions and 11 adenocarcinomas, and 60 of 65 adenomas (92.3%) failed to show nuclear p53 reactivity. These results suggest that increased expression of Mdm2 is an early event in circumanal gland tumorigenesis, and may be present in the absence of nuclear p53 protein accumulation.

Development of multidrug resistance in a canine lymphoma cell line

New multidrug resistant cell lines developed from the canine B cell lymphoma cell line (GL-1) were characterized in terms of chemosensitivity to some antineoplastics and P-glycoprotein (Pgp) expression. GL-1 was continuously exposed to a culture medium containing gradually increasing levels of doxorubicin and the cells that could grow in the presence of doxorubicin were obtained. Chemosensitivity of these cells to various antineoplastics were investigated with or without verapamil, which reversed Pgp-mediated drug resistance. The expression of Pgp on the cells was also examined by Western blot analysis. As a result, three kinds of resistant cell lines, designated as GL-DOX60, 300, and 4000 were obtained. These cell lines showed stable proliferation in the medium containing 60, 300, and 4000 ng/ml, respectively. These cells were much more resistant to vincristine than doxorubicin. This resistance was strongly reversed by the presence of verapamil. On the other hand, cisplatin was effective enough in killing these derived cells. In the Western Blot analysis, some bands that reacted to the anti-human Pgp monoclonal antibodies were observed in GL-DOX4000. The cells derived from GL-1 have multidrug resistance potential mediated by canine Pgp. The cells produced in this experimental trial are considered to be useful models for various investigations on canine multidrug resistance.

Overexpression of lipoprotein lipase improves insulin resistance induced by a high-fat diet in transgenic rabbits

AIMS/HYPOTHESIS

Dysfunctions of lipoprotein lipase (LPL) have been found to be associated with dyslipidaemias, atherosclerosis, obesity and insulin resistance. There are two conflicting hypotheses regarding the roles of LPL in glucose metabolism and insulin resistance. Whether systemically increased LPL activity would be beneficial or detrimental to insulin sensitivity is yet to be resolved. To address this issue, we studied transgenic rabbits overexpressing human LPL transgene.

METHODS

LPL transgenic and control rabbits were fed a 10% high-fat diet (HFD) for 16 weeks. To evaluate glucose metabolism, we compared plasma levels of glucose and insulin in transgenic rabbits with control rabbits and performed an intravenous glucose tolerance test. In addition, we measured adipose tissue accumulation in HFD-fed rabbits.

RESULTS

Increased LPL activity in transgenic rabbits resulted in a significant reduction of plasma triglycerides and non-esterified fatty acids, but not in basal levels of glucose and insulin. HFD feeding induced an elevation of plasma glucose levels accompanied by hyperinsulinaemia in control rabbits, but was significantly inhibited in transgenic rabbits. The intravenous glucose tolerance test showed that transgenic rabbits had faster glucose clearance associated with lower levels of insulin secretion than control rabbits. In addition, there was a significant reduction of body adipose tissue in transgenic rabbits compared with in control rabbits fed an HFD. Scanning electron microscopic examination revealed that adipocytes in transgenic rabbits were predominately small cells.

CONCLUSIONS/INTERPRETATION

Our results showed that systemically increased LPL activity improves insulin resistance and reduces adipose accumulation in transgenic rabbits, indicating that systemic elevation of LPL may have potential benefits for the treatment of insulin resistance and obesity.

Quantitative electroencephalography of medetomidine, medetomidine-midazolam and medetomidine-midazolam-butorphanol in dogs

The purpose of this study was to evaluate the effects of the administration of an alpha2-adrenoceptor agonist alone and in combination with other derivatives on brain wave activity. In addition, the diagnostic values of the electroencephalogram (EEG) for judging the depth of the balanced anaesthesia with an alpha2-adrenoceptor agonist was evaluated. The treatments comprised 20 microg/kg medetomidine (Me-20), 80 microg/kg medetomidine (Me-80), 20 microg/kg medetomidine and 0.5 mg/kg midazolam (Me-Mi) administered intramuscularly, and 20 microg/kg medetomidine with 0.5 mg/kg midazolam and 0.1 mg/kg butorphanol (Me-Mi-Bu). The EEG was recorded continuously at pre-administration, and at 7, 10, 20, 30, 45 and 60 min after administration. The recorded data were analysed by separating the power spectrum into 1-3, 4-7, 8-13 and 14-30 Hz bands. Spectral-edge analysis was used to calculate the spectral edge frequency 90 (SEF90) and the median edge frequency (MEF). Time-related changes in power spectrum analysis showed a significant increase in the Me-80 group in the 1-3 Hz band. The power for 1-3 Hz in the Me-80 group was significantly higher than in all the other groups. In the 14-30 Hz band, there was a significant reduction of power in all groups following administration of the agents. The SEF90 frequencies were significantly reduced in all groups except for the Me-20 group after administration of the agents. The SEF90 frequencies in the Me-20, Me-Mi and Me-Mi-Bu were all significantly higher than those in the Me-80 group. However, there was no significant difference between the Me-20, Me-Mi and Me-Mi-Bu groups in any analyses. Our results demonstrated that the changes in quantitative EEG made by the Me-Mi-Bu and Me-Mi groups were similar to those made by Me-20 groups. Present results suggest that the EEG should be interpreted with caution in assessing the anaesthetic level in balanced anaesthesia in dogs.

Expression of T helper 1 and T helper 2 cytokine mRNAs in freshly isolated peripheral blood mononuclear cells from dogs with atopic dermatitis

Using reverse transcription-polymerase chain reaction (RT-PCR) and semi-quantitative PCR techniques, mRNA expression for canine interferon (IFN)-gamma, interleukin (IL)-4, IL-5 and IL-10 in freshly isolated peripheral blood mononuclear cells (PBMCs) was examined in dogs with or without atopic dermatitis (AD). The expression of IFN-gamma mRNA in dogs with AD was lower than that in dogs without AD (healthy control). The expression of IL-5 mRNA was higher in dogs with AD than in control dogs, but there were no significant differences in IL-4 mRNA and IL-10 mRNA expression between the groups. The number of circulating eosinophils was higher in dogs with AD than in control dogs, although eosinophilia was found in only one dog with AD. These results suggest that there is a tendency for the PBMCs of atopic dogs to express a type 2 cytokine pattern that is similar to the pattern observed in human AD patients.

Hydrocephalus and syringomyelia in a cat

A 3-month-old male Japanese cat with feline parvovirus infection, showing central and cervical nerve abnormalities, was diagnosed as hydrocephalus and syringomyelia by use of magnetic resonance imaging (MRI). The cat was maintained clinically by medical treatment even though he could not stand. The MRI scans obtained about 5 months later showed that the ventricles had increased in size and the cervical syrinx had extended into the thoracic spinal cord. Ventriculoperitoneal (VP) shunt was performed. One week after surgery, neurological conditions had improved. At the postoperative MR images, the ventricles had decreased in size and the syrinx in the cervical and thoracic spinal cord could no longer be seen. The cat was still alive and was able to walk well.

Ivermectin treatment of demodicosis in 56 hamsters

Fifty-six hamsters with demodicosis were treated with daily oral administration of ivermectin (0.3 mg/kg). Thirty-three cases (58.9%) were cured and 6 cases (10.7%) had improved clinically but needed to continue treatment. Of 5 cases (8.9%) who relapsed within 3 months and were retreated with ivermectin, 4 were cured and 1 needed further treatment. Five cases (8.9%) had improved clinically but died within 3 months. Seven cases (12.5%) had not improved and died within 3 months. Overall 49 (87.5%) hamsters had improved clinically. No significant differences in prognosis of demodicosis were detected according to sex, breed, age and clinical features, but the prognosis of demodicosis in hamsters with concurrent disease was poor.

Effect of medetomidine on electroencephalography and use of a quantitative electroencephalograph for evaluating sedation levels in dogs

This study was designed to characterize the effect of medetomidine (Med) on canine electroencephalography (EEG), to evaluate the use of quantitative EEG for assessing sedation levels and to explore the correlation between the serum concentration of Med and the quantitative EEG. Four groups of dogs were given Med at doses of 20, 40, 80 and 160 microg/kg (Med-20, Med-40, Med-80 and Med-160 groups). Following Med administration, there was synchrony between each unipolar EEG lead. On EEG power spectrum analysis of the bipolar leads, all groups showed a significant depression of the 14-30 Hz components. The power of the 1-3 Hz component in the Med-80 and Med-160 groups was significantly increased, although there were few changes in the other groups. Similar results were obtained from raw data analysis. As a result of quantitative EEG analysis, spectrum edge frequency 90 analysis (SEP90) showed that the frequency was significantly reduced in all groups after Med administration. A dose-response effect was observed in all groups except for the Med-160 group. Both of these EEG analyses were significantly correlated with the serum concentration of Med. However, the result of the SPF90 analysis sugested a stronger correlation than that for median edge frequency analysis. In conclusion, care must be taken in veterinary clinical diagnoses when Med is used during EEG recording, as Med may cause increased activity in the low frequency band and a decrease in high frequency band activity. In addition, quantitative EEG analysis may be useful in assessing the depth of sedation and in further studies on Med administration.

[Two cases of intravascular lymphomatosis diagnosed antemortem by transbronchial lung biopsy]

Patient 1 was a 71-year-old man who had been admitted to our hospital with high-grade fever. Chest computed tomographic (CT) images revealed clear peripheral and high-density central areas. Abnormal laboratory findings included elevated LDH and hypoxemia. Interstitial pneumonia was suspected, and transbronchial lung biopsy (TBLB) confirmed the diagnosis of intravascular lymphomatosis (IVL). The patient succumbed before completion of chemotherapy. Patient 2 was a 65-year-old man admitted with high-grade fever. Abnormal laboratory findings included pancytopenia, hypoxemia, and elevated levels of LDH and soluble interleukin-2 receptor. Chest CT images revealed diffuse, mildly dense areas in the upper fields of both lungs. TBLB specimens yielded a diagnosis of IVL. Complete clinical remission was obtained with CHOP multiagent chemotherapy. Although IVL is usually diagnosed at autopsy, in these 2 cases an antemortem diagnosis was made on the basis of TBLB findings. Also, multiagent chemotherapy achieved a complete clinical remission in Patient 2.

Antemortem evaluation for magnetic resonance imaging of the equine flexor tendon

In this study antemortem evaluation of equine flexor tendons--the superficial digital flexor tendon and the deep digital flexor tendon--using magnetic resonance (MR) images was performed. Postmortem flexor tendons were used to prepare the slice positions, coil and body positions for MR imaging. It was possible by this method to take antemortem MR images of equine limbs that distinguished features as well as postmortem images described in previous studies. The total time of antemortem scanning was about 40 min. This study is the first to report antemortem MR images in horses.

In-vitro anti-proliferative effects of some anti-tumour drugs on feline mammary tumour cell lines

Six anti-tumour drugs namely; doxorubicin, mitoxantrone, vincristine, cisplatin, recombinant human tumour necrosis factor alpha (rh-TNFalpha) and recombinant feline interferon gamma (rf-IFNgamma) were singly evaluated for their anti-proliferative effects on two feline cell lines (FRM and NAC) derived from mammary adenocarcinoma and grown as monolayers. We obtained concentration response curves that enabled the determination of the concentration inhibiting growth by 50 per cent (IC50) for the chemotherapeutic agents with VCR exhibiting exponential-plateau curves. Differences in anti-proliferative effects of drugs to a given cell line and between the cell lines were also observed. NAC cells were relatively more resistant compared with FRM cells. The relative resistances for NAC cells were 4.19, 12.96, 0.05 and 2.10-fold to doxorubicin, mitoxantrone, vincristine and cisplatin, respectively. FRM cells were more resistant to VCR at lower concentrations compared with NAC cells. The cells appeared, at least in vitro, least sensitive to rh-TNFalpha and rf-IFNgamma. rh-TNFalpha and rf-IFNgamma were 23 and 29 per cent inhibitory to FRM cells and only 13 and 15 per cent inhibitory to NAC cells, respectively.

Abscess of bovine brain stem diagnosed by contrast MRI examinations

A 3-month-old, female Japanese Black calf that showed signs of neurological dysfunction soon after birth was twice examined by magnetic resonance imaging (MRI). Survey MR images showed changes in a hydrocephalus from mild to severe and the existence of a mass above the brain stem that could be distinguished from the surrounding cerebral parenchyma. Contrast MRI examinations using Gd-DO3A-butriol showed the mass to have a doughnut-like form. As the mass changed, the clinical signs aggravated. We diagnosed a brain stem abscess, which we confirmed pathologically. To our knowledge there are no other reports of the use of contrast MRI to examine cattle.

The advantage of magnetic resonance imaging in diagnosis of cauda equina syndrome in dogs

Three dogs were evaluated in our study using magnetic resonance imaging (MRI) to reveal the anatomical deformity and the degree of the lesion of cauda equina. In all dogs, MRI revealed soft tissue, such as cauda equina, epidural fat, and intervertebral disc, at the lumbosacral region clearly without contrast medium. Our results suggest that MRI has some advantages in evaluating cauda equina syndrome in dogs.

Establishment and characterization of a new cell line derived from feline mammary tumor

A new cell line designated FRM was established from pleural effusion of a 13-year-old female cat with mammary adenocarcinoma. The cell line exhibited irregular round and polygonal shaped epithelial cells and demonstrated cell growth in a monolayer fashion with a doubling time of 22.4 hr. It possessed a modal chromosome number of 79. The immortality of this cell line was demonstrated using the TRAP assay which revealed a high telomeric activity of these cells. Scatchard analysis revealed quite low levels of estrogen receptors in both tumor mass produced in nude mice and FRM cells. Subcutaneous transplantation of the cells produced localized palpable masses in athymic nude mice within two weeks. This cell line may provide a good model for in vivo and in vitro studies on feline mammary tumors.

A comparative study of germinal center: fowls and mammals

The mammalian germinal center is organized into a dark zone containing proliferating centroblasts and a light zone filled with nondividing B cells (called centrocytes), follicular dendritic cells and a few scattered T cells. We clarified these two zones in the chicken germinal center with immunohistology. Proliferating cells and immunoglobulin negative cells were detected in the circumference ring of the chicken germinal center. The central part of the chicken germinal center contained B cells expressing immunoglobulin, follicular dendritic cells and a few T cells. Most of the B cells in the central part of the chicken germinal center did not enter into the S phase. These results suggest that the chicken germinal center is also organized into the dark zone (the circumference ring of germinal center) and the light zone (the central part of germinal center).

Development of maternal IgG-free chick obtained from surgically bursectomized hen

IgG-free eggs and chicks were developed, so as to study the role of maternal IgG in the development of the immune system. Surgical bursectomy on the 18th day of incubation deprived chickens of B cells and eliminated IgG synthesis. Bursectomized chickens are usually dead before sexual maturity under conventional conditions. When surgically bursectomized chickens were housed in an isolated clean room and antibiotics were administered to them, they could survive to sexual maturity. Finally, we succeeded in obtaining IgG-free fertilized eggs and maternal IgG-free chicks from surgically bursectomized hens. The amount of yolk IgG in IgG-free eggs was one-ten thousandth less than that in normal eggs. The level of IgM in the serum of maternal IgG-free chicks reached six times higher than that of normal chicks 5 days after hatching.

Developmental change of lateral ventricular volume and ratio in Beagle-type dogs up to 7 months of age

Eighteen healthy Beagle-type dogs were studied using magnetic resonance (MR) imaging from a few days after birth up to 7 months of age. We evaluated the onset of lateral ventricular expansion, the developmental change of lateral ventricular volume and the ratio of the largest to the smallest lateral ventricular volume. The onset of lateral ventricular expansion was defined as the day that the expansion by cerebrospinal fluid (CSF) was first visible in unilateral or bilateral lateral ventricles on the transverse images at the level of the intraventricular foramen. It was found that the expansion of lateral ventricles were first detectable at 3-4 weeks. Lateral ventricular volume ratio varied most from the onset of lateral ventricular expansion to 75 days of age and stabilized after that, although absolute brain and lateral ventricular volumes continued to increase.

Appearance of canine abdominal tumors with magnetic resonance imaging using a low field permanent magnet

The study was carried out to evaluate the applicability of magnetic resonance imaging (MRI) in detecting tumors in the abdomen of the dog. Abdominal ultrasound and MRI were performed on 8 dogs having a mass lesion on abdominal radiography. MR images were obtained in the transverse, sagittal and dorsal planes using T1- and T2-weighted spin echo pulse sequences. There was good visual correlation of the lesion site by MRI and ultrasonography (US).

Magnetic resonance imaging of the lateral ventricles in beagle-type dogs

Magnetic resonance (MR) imaging was performed on 21 presumed normal Beagle-type dogs. The size and symmetry of their lateral ventricles were evaluated and dogs were categorized on the basis of the percentage of their ventricular height (Vh) to brain height (Bh) and the ratio of the largest to the smallest ventricular area (rVA). Eleven dogs had lateral ventricles classified as normal sized (0-14% Vh/Bh) while 10 of 21 dogs had moderate enlargement (15-25% Vh/Bh) of one or both lateral ventricles. None of the dogs had severe lateral ventricular enlargement. Degree of asymmetry was also arbitrarily categorized on basis of rVA as normal to minimal (rVA < 1.5), mild (1.5 < rVA < 2.0), or severe (2.0 < rVA). Of the dogs having normal-sized lateral ventricles, six of eleven had symmetric, three of eleven had mildly asymmetric and two of eleven had severely asymmetric lateral ventricles. Of the dogs having at least one moderately enlarged lateral ventricles, five of ten had symmetric lateral ventricles, and two of ten had mild asymmetry and three of ten had severe asymmetry. Gender and body weight had no statistical relationship to lateral ventricle symmetry. Clinically insignificant ventricular enlargement and asymmetry was common in this group of Beagle dogs.

Primary brain tumors in two dogs treated by surgical resection in combination with postoperative radiation therapy

Primary brain tumors in two dogs were surgically removed followed by postoperative radiation therapy. The two tumors were confirmed histologically to be astrocytoma and meningioma, respectively. After the surgery, the neurological status of each dog improved dramatically and a total dose of 40 Gy was delivered to the surgical site to treat residual tumor tissue. Although the dog with astrocytoma died 6 months after surgery due to unknown causes, the dog with meningioma has lived for over 24 months with a degree of neurological disorder less severe than that before treatment. These results suggested the effectiveness of this type of therapy on brain tumor in dogs and therapeutic modality should be positively planned to treat canine brain tumors.

Clinical and pathological findings of a Yorkshire terrier affected with necrotizing encephalitis

A three-year-old, male Yorkshire terrier was presented with blindness, circling, hind limb weakness, and convulsive seizure for the past 3 months. Characteristic clinical findings were chronic, progressive neurological signs involving cerebrum and brain stem, an elevation of brain-type isoenzyme of serum creatine kinase, appearance of high voltage slow activity in electroencephalogram, and multifocal lesions in the cerebral hemispheres on magnetic resonance imaging. Necrotizing encephalitis of Yorkshire terrier was diagnosed after postmortem pathological examination. This is the first case report of the disease in Japan.

Cryopreservation of isolated rat islets of Langerhans in the presence of ethylene glycol or dimethyl sulfoxide: evaluation of toxicity and the dynamic pattern of subsequent insulin release in vitro

The toxic effect of ethylene glycol (EG) on the pattern of dynamic insulin release from rat pancreatic islets with or without freezing was investigated in comparison with that of dimethyl sulfoxide (Me2SO). Sixty islets were perifused (1 ml/min) consecutively with D-glucose (1.67 mM for 30 min followed by 16.7 mM for 60 min and 1.67 mM for 60 min) after exposure to 2.0 M EG or Me2SO for 1 h at either 22 or 0 degrees C. During the second period of perifusion, the insulin output from islets exposed to Me2SO or EG at 22 degrees C decreased to 53 and 51% of that from nontreated control islets, respectively. On the other hand, the islets exposed to EG at 0 degrees C exhibited 86% of the control insulin output under the same perifusion conditions, and this appeared to be higher than that of islets exposed to Me2SO (60%) at 0 degrees C. Frozen islets, after exposure to 2.0 M EG or Me2SO for 1 h at 0 degrees C, responded positively to 16.7 mM D-glucose, and the typical biphasic pattern of insulin secretion was observed. The insulin output from these islets during the second period of perifusion was not comparable to that from unfrozen control islets. In particular, the mean insulin output of EG-cryopreserved islets during the second period accounted for 99% of that from unfrozen control islets. The present findings suggest the possible use of EG as an alternative cryoprotectant to Me2SO.

Establishment and characterization of a new canine B-cell leukemia cell line

A new cell line derived from a spontaneous canine leukemia was established and designated GL-1. The cells have been cultured in a floating fashion and passaged for over two years. They were round with rich cytoplasm containing many rough endoplasmic reticula and mitochondria. Peroxidase staining was negative. The nuclei of many cells were round, but segmented nuclei were seen frequently. The doubling time of the cells was 27.3 hr and they had 78 chromosomes. Surface marker analysis using monoclonal antibodies (MABs) and flowcytometry revealed that GL-1 possessed CD45 and surface IgG. However, the cells did not react with MABs detecting T-cell markers. These results indicate that GL-1 has a lymphocytic lineage and is derived from a B-cell leukemia.

Histopathological findings on ulcerative lesions of carpal and tarsal joints in Japanese black cattle

In order to determine the pathogenesis of ulcerative lesions of the articular cartilages in Japanese Black cattle, tissue samples of the ulcerative lesion, marginal portion of the ulcer, macroscopically normal portions and synovial membranes were histopathologically examined by light microscopy, scanning electron microscopy and contact microradiography. The results are summarized as follows: (1) In the ulcerative lesions, degeneration and complete destruction of articular cartilage and its replacement with a proliferation of myelogenic connective tissue were observed. (2) In macroscopically normal portions, fissures of the articular surface and changes of the trabecular pattern in subchondral bone were present. (3) In the marginal portions of the ulcerative lesions, evidences of the repair process such as connective tissue growth from subchondral bones and articular cartilages were seen. (4) In synovial membranes, no pathological findings were observed. And (5) among the above mentioned changes, no inflammatory findings were seen. In conclusion, the ulcerative lesions of bovine articular cartilage may be regarded as the early stage of osteochondrosis to osteoarthrosis since the findings such as noninflammatory destruction or degeneration and remodeling of the joints are characteristics of the latter.

Effects of 6-Hydroxydopamine on the antibody response to the hapten dinitrophenyl in the chicken

Antibody responses to the hapten dinitrophenyl (DNP) and the concentration of catecholamine in chickens received a single injection of 6-Hydroxydopamine (6-OHDA) into the chorioallantoic cavity at the embryonal stage were evaluated. A significantly enhanced anti-DNP IgA response and a markedly decreased level of noradrenaline in the peripheral blood were observed in chickens treated with 400 micrograms of 6-OHDA at 14 days of incubation. These results suggested the immunomodulatory influence of the sympathetic nervous system.

Changes in lymphoproliferation and DTH responses after vaccination immediately before surgery in puppies

To clarify the effects of the presurgical vaccination canine parvovirus vaccine (CPV) on immunological responses to surgery in puppies, we assessed it by measuring the blastogenic responses of lymphocytes and delayed type hypersensitivity (DTH) responses after laparotomy in the non- and vaccinated puppies. The inhalation anesthetic used was isoflurane or halothane. In post-surgery, the blastogenic responses of lymphocytes in the non-vaccinated puppies decreased, especially, those in these puppies with halothane anesthesia (GOF) did significantly, and the duration of this decrease prolonged more than that in the non-vaccinated puppies with isoflurane anesthesia (GOI). However, the responses in the vaccinated puppies with each anesthesia didn't almost decrease below the presurgical levels. In GOI groups, the DTH responses in vaccinated puppies increased significantly over those in non-vaccinated ones, but in GOF groups, there were few differences between the DTH responses in the non- and vaccinated puppies. These results suggest that the CPV vaccination immediately before surgery possibly prevents the postsurgical immunosuppression, and that GOI may depress the immunocompetence less than GOF.

Differential freezing tolerance of rat pancreatic islets depending on their size variation

We have investigated the freezing tolerance of rat pancreatic islets. Freshly isolated rat pancreatic islets were divided into three groups based on their longest diameter (small; 100 - 200 microns, medium; 201 - 300 microns, large; > 300 microns). They were then cryopreserved at a slow cooling rate (-0.3 degrees C/min) in the presence of dimethyl sulfoxide (Me2SO) or ethylene glycol (EG). After storage at -196 degrees C for 1 - 4 weeks, they were thawed and their ability to secrete insulin in response to fluctuations in glucose concentration was examined during three consecutive static incubations in vitro (1st; 2.8 mM, 2nd; 16.7 mM, 3rd; 2.8 mM). Morphological examination of the beta-granule population was determined by image analysis, and correlation with islets size was analyzed. The amount of insulin released from large-sized islets was significantly suppressed in EG (p < 0.05) and Me2SO (p < 0.01) groups compared to unfrozen islets. However, the mean volume of the large-sized islets isolated from one rat accounted for 43.0% of the total volume. On the other hand, the amount of insulin released from small- and medium-sized islets did not differ from those of unfrozen islets, and their mean volumes were 13.2 and 43.8% respectively. The percentage of cells with beta-granules was significantly correlated with size in both EG (r = -0.52) and Me2SO (r = -0.35) groups, but no significant correlation was observed in the unfrozen islets groups. These findings suggest that large-sized islets are more susceptible to freezing injury than small- or medium-sized islets. Moreover, the volume distribution of isolated islets indicated that it may be important to retain the ability of insulin secretion from the large-sized islets.

Effect of directly ultraviolet-irradiated allografts of fetal pancreas in experimental diabetic dogs

The proliferative responses of UV-irradiated islets from fetal pancreas decreased to 53.8 +/- 4.7% (mean +/- SEM) compared to that of UV-irradiated islets by allogeneic mixed islet-cell lymphocyte culture. In 5 pancreatectomized dogs, UV irradiated fetal dog pancreas was transplanted either into omentum pouches or the spleen without immunosuppressive agents. The diabetic status (daily insulin requirement for hyperglycemia, decrease in body weight, urine glucose) improved in dogs after allo-transplantation. The survival time after total pancreatectomy was significantly longer in allografted dogs than those treated only with daily insulin injections.

Clinical evaluation of titration of hepatitis C virus core antibody and its subclasses

Titrations of anti-hepatitis C core (anti-HCc) immunoglobulin G (IgG) antibodies and its subclasses were studied in 90 patients with acute and chronic hepatitis C virus (HCV) infection, including 27 patients who underwent interferon (IFN) therapy. The positivity rates for each anti-HCc subclass were as follows: 95.2% for IgG1, 12.0% for IgG2, 69.9% for IgG3 and 19.3% for IgG4. The total anti-HCc IgG titre correlated well with the IgG1, titre, indicating that IgG1 was the main virus-specific IgG. Changes of IgG1 production mainly contributed to fluctuations of the anti-HCc IgG titre and corresponded well to positivity for HCV-RNA during and after IFN therapy. IgG3 was detected prior to IgG1 during the early phase of acute hepatitis in some cases and also appeared with relapse after IFN therapy. The serial assay of anti-HCc subclasses showed the patients' humoral immune response to HCV infection, and might be useful for evaluation of anti-viral immunity influenced by IFN therapy.

Flow cytometric analysis and immunohistochemistry of delayed-type hypersensitivity responses in mice immunized with rat hepatocytes

Delayed-type hypersensitivity (DTH) responses to rat hepatocytes (HCs) in mice were investigated by flow cytometric analysis and immunohistochemistry with monoclonal antibodies directed against murine class II, CD4, and CD8 antigens. Mice were immunized subcutaneously (s.c.) with 10(6) rat HCs (referred to as s.c.-immunized mice), and control mice were injected s.c. with sterile Hanks' solution (non-immunized mice). Four days later, 10(5) rat HCs were injected into the footpad of s.c.-immunized mice and non-immunized mice. The DTH response in s.c.-immunized mice significantly increased after challenge when compared to that in non-immunized mice. The numbers of class II+, CD4+, and CD8+ cells in the footpad, and CD4+ and CD8+ cells in the inguinal lymph node of s.c.-immunized mice significantly increased during the DTH response. An increase in the number of CD4+ cells in the footpad of s.c.-immunized mice after challenge was more significant than that of non-immunized mice. The number of CD4+ cells increased more markedly in the footpad of s.c.-immunized mice as compared to that of CD8+ cells. Furthermore, immunohistochemical studies of the footpad of s.c.-immunized mice showed more severe infiltration of CD4+ cells rather than CD8+ cells at the injection site of rat HCs. These results suggest that the DTH response in the footpad of mice immunized with rat HCs is associated with severe infiltration of CD4+ cells.

Immunological responses to polyvalent canine vaccines in dogs

The immunological responses to commercially available polyvalent vaccines in dogs were examined. There was a tendency in decreased lymphocyte counts on day 7 in the puppy and adult dogs. There was a significant increase in the blastogenesis of lymphocytes on day 7 and 21 in puppies, whereas no significant changes were seen in the adult dogs. Delayed type hypersensitivity (DTH) responses to phytohemagglutinin (PHA) and canine parvo-virus (CPV) vaccine monitored 0, 3, 8 weeks after vaccination produced strong reactions, in particular those to CPV vaccine rose significantly after vaccination and maintained the higher responses for at least 2 months. Therefore, it is considered that vaccination is immunomodulative rather than immunosuppressive and that DTH responses to PHA and CPV vaccine are helpful to monitor non-specific and specific immune functions in vivo.

Clinical study of IgA antibody against hepatitis C virus core antigen in patients with type C chronic liver disease

Immunoglobulin A class antibody to hepatitis C virus core antigen (IgA anti-HCc) was measured in the serum of 128 patients with type C chronic liver disease. Fifty-eight patients (45.3%) were seropositive. IgA anti-HCc was detected in only one of 20 patients with chronic persistent hepatitis; however, 52.3% (46/88) of patients with chronic active hepatitis and 55% (11/20) of patients with liver cirrhosis were seropositive. Histological examination revealed that 22 (71.0%) of 31 patients with severe disease activity were seropositive compared to 35 (44.9%) of 78 patients with moderate (P < 0.05) and one (5.3%) of 19 patients with mild (P < 0.01) histological changes. IgA anti-HCc was measured sequentially in 65 patients who underwent interferon therapy. There was a significant difference between responders and other patients in the mean ratio of IgA anti-HCc titers one month after therapy. Three months after therapy, IgA anti-HCc was detectable in only two of 15 responders who were IgA anti-HCc seropositive at the start of therapy. In contrast, IgA anti-HCc reappeared three months after therapy despite a temporary decrease to undetectable levels in all nonresponders. We conclude that IgA anti-HCc is a useful marker to identify the presence of active type C liver disease and that the disappearance of IgA anti-HCc three months after interferon therapy predicts a good response in treated patients.

Detection of Hepatozoon canis oocyst from ticks collected from the infected dogs

We collected 220 ticks from 58 dogs infected with Hepatozoon canis from 1990 to 1992 in Yamaguchi and Fukuoka prefectures, the western provinces of Japan. These ticks were identified as Haemaphysalis campanulata, H. longicornis, H. flava, Ixodes ovata, and I. nipponensis. By histopathological examination of these ticks, two oocysts which seemed to be those of H. canis were observed in the haemocoele of an adult female H. longicornis and a nymph H. flava tick. The oocyst, about 300 x 150 microns in size, was composed of 50 to 70 sporocysts with 10 to 16 banana-shaped sporozoites each.