Alpha-lipoic acid reduces congenital malformations in the offspring of diabetic mice

BACKGROUND

The mechanism of diabetes-induced congenital malformation remains to be elucidated. It has been reported that alpha-lipoic acid (LA) prevents neural tube defects (NTDs) in offsprings of rats with streptozotocin-induced diabetes. Here, we evaluate the protective effect of LA against diabetic embryopathy, including NTDs, cardiovascular malformations (CVMs), and skeletal malformations, in mice.

METHODS

Female mice were rendered hyperglycemic using streptozotocin and then mated with normal male mouse. Pregnant diabetic or non-diabetic mice were treated daily with either LA (100 mg/kg body weight) or saline between gestational days 0 and 18. On day 18, fetuses were examined for congenital malformations.

RESULTS

Plasma glucose levels on day 18 were not affected by LA treatment. No congenital malformations were observed either in the saline-treated or LA-treated non-diabetic group. In the saline-treated diabetic group, 39% of fetuses had external malformations and 30% had NTDs. In the LA-treated diabetic group, the corresponding proportions were 11 and 8%, respectively. LA treatment also decreased the incidence of CVMs from 30-3% and of skeletal malformations from 29-6%.

CONCLUSIONS

We conclude that LA can reduce NTDs, CVMs and skeletal malformations in the offspring of diabetic mice at term delivery.

Motor training in the manipulation of flexible objects in haptic environments

A system with interchangeable constraints for studying skillful human movements via haptic displays is presented. It is shown how this system can be applied to the analysis of reaching movements in the manipulation of flexible objects. In the experiment, progress in arm motor training is considered for several subjects. Experimental data are obtained for slow, moderate, and fast movements. Future applications of the system and its limitations are discussed.

Gastroinvasive Helicobacter Infection in an Ocelot (Leopardus pardalis)

Highly invasive Helicobacter-like organisms were found in a 19-year-old female ocelot (Leopardus pardalis) with multiple ulcers in the fundic region of the stomach. The bacteria, resembling Helicobacter heilmannii, were located largely within canaliculi or in the cytosol of parietal cells. Except in the ulcerative lesions, parietal cells were hyperplastic, while chief cells and neck mucous cells were reduced in number. The term "gastroinvasive Helicobacter-like organism" was applied. It seems probable that this organism differs from other Helicobacter organisms in pathogenicity, and possible that its behaviour in vitro would help it to evade antibacterial treatment.

Realistic Virtual Endoscopy of the ventricle system and haptic-based surgical simulator of hydrocefalus treatment

New methods and software tools for automatic extraction of the ventricle system from magnetic resonance imagery (MRI) data, ventricle part classification, and realistic texturing are proposed to support Virtual Endoscopy (VE). Volume- and surface-based medical atlases are intensively used as templates in the methods. The processed ventricle-related surfaces are then utilized in a haptic-based system, which provides a surgeon with several basic functions simulating "virtual treatment" of hydrocephalus.

Clinical implications of dynamic MRI for pituitary adenomas: clinical and histologic analysis

To determine the clinical significance of dynamic magnetic resonance imaging (MRI) for pituitary adenomas, we analyzed sequential enhancement patterns of pituitary adenomas and factors contributing to these sequential patterns. Dynamic MRI was performed in 67 patients with pituitary adenomas and compared to conventional imaging. Subjects were classified into four categories according to the sequential enhancement patterns of the adenomas. Factors supposed to correlate with enhancement pattern, such as secreting hormone, tumor size, microscopically examined vascularity and arterial involvement, and intraoperatively observed texture of the adenomas, were examined among the groups. Adenomas inclined to have late enhancement patterns were relatively small compared to those with early patterns. Tumors with very early enhancement patterns were significantly more fibrous than those with the other three patterns. The factors that contribute to sequential enhancement patterns remain unclear. None the less, scrutinizing the dynamic sequential pattern may provide useful information about the probable texture of the tumor.

Thickening of sphenoid sinus mucosa during the acute stage of pituitary apoplexy

The authors treated two patients with pituitary apoplexy in whom magnetic resonance (MR) images were obtained before and after the episode. Two days after the apoplectic episodes, MR imaging demonstrated marked thickening of the mucosa of the sphenoid sinus that was absent in the previous studies. The relevance of this change in the sphenoid sinus was investigated. Retrospective evaluations were performed using MR images obtained in 14 consecutive patients with classic pituitary apoplexy characterized by acute onset of severe headache. The mucosa of the sphenoid sinus had thickened predominantly in the compartment just beneath the sella turcica, in nine of 11 patients, as ascertained on MR images obtained within 7 days after the onset of apoplectic symptoms. This condition improved spontaneously in all four patients who did not undergo transsphenoidal surgery. The sphenoid sinus mucosa appeared to be normal on MR images obtained from three patients at the chronic stage (> 3 months after onset). The incidence of sphenoid sinus mucosal thickening during the acute stage was significantly higher in the patients with apoplexy than that in the 100 patients without apoplexy. A histological study conducted in four patients who underwent transsphenoidal surgery during the early stage showed that the subepithelial layer of the sphenoid sinus mucous membrane was obviously swollen. The sphenoid sinus mucosa thickens during the acute stage of pituitary apoplexy. This thickening neither indicates infectious sinusitis nor rules out the choice of the transsphenoidal route for surgery.

Quantitative MR evaluation of intracranial epidermoid tumors by fast fluid-attenuated inversion recovery imaging and echo-planar diffusion-weighted imaging

BACKGROUND AND PURPOSE

Quantification of MR can provide objective, accurate criteria for evaluation of a given MR sequence. We quantitatively compared conventional MR sequences with fast fluid-attenuated inversion recovery (fast-FLAIR) and echo-planar diffusion-weighted (DW) MR imaging in the examination of intracranial epidermoid tumors.

METHODS

Eight patients with surgically confirmed intracranial epidermoid tumors were examined with T1-weighted MR sequences, fast T2- and proton density-weighted dual-echo sequences, fast-FLAIR sequences, and DW echo-planar sequences. We measured the MR signal intensity and apparent diffusion coefficient (ADC) of epidermoid tumors, normal brain tissue, and CSF and calculated the tumor-to-brain and tumor-to-CSF contrast ratios and contrast-to-noise ratios (CNR). Results were compared among the five MR methods.

RESULTS

On fast-FLAIR imaging, the mean signal intensity of epidermoid tumors was significantly higher than that of CSF but significantly lower than that of the brain; the contrast ratio and CNR of tumor-to-CSF were 4.71 and 9.17, respectively, significantly greater than the values with conventional MR imaging. On echo-planar DW imaging, epidermoid tumors showed a remarkably hyperintense signal relative to those of the brain and CSF; the mean contrast ratio and CNR of tumor-to-CSF were 13.25 and 19.34, respectively, significantly greater than those on fast-FLAIR or conventional MR imaging. The mean ADC of epidermoid tumors was 1.197 x 10(-3) mm(2)/s, significantly lower than that of CSF but higher than that of brain tissues.

CONCLUSION

Fast-FLAIR imaging is superior to conventional MR imaging in depicting intracranial epidermoid tumors. Echo-planar DW imaging provides the best lesion conspicuity among the five MR methods. The hyperintensity of epidermoid tumors on echo-planar DW imaging is not caused by the diffusion restriction but by the T2 shine-through effect.

Expression of ZAKI-4 messenger ribonucleic acid in the brain during rat development and the effect of hypothyroidism

We identified ZAKI-4 (also designated as DSCR1L1) as a thyroid hormone responsive gene in cultured human skin fibroblasts. Recently it has been reported that ZAKI-4 belongs to an evolutionary conserved family of proteins that function as calcineurin inhibitor. In human, ZAKI-4 and calcineurin are highly expressed in brain, where thyroid hormones play essential roles in the development during fetal and neonatal periods. In the present study, we examined the temporal and spatial expression patterns of ZAKI-4 messenger RNA (mRNA) in control and hypothyroid rat brains. Northern blot analysis revealed that ZAKI-4 mRNA was detected in both cerebral cortex and cerebellum as early as embryonic day (E)18. In the cerebral cortex, the expression level gradually increased with age, reaching a plateau at postnatal day (P)7 and remained constant thereafter until P30. A similar pattern of increase with age was also observed in hypothyroid rats; however, the magnitude of the increase was significantly reduced. In control rats, the fold increase in ZAKI-4 mRNA level from E18 to P17 was 10.8; whereas in hypothyroid rats, it was 7.4. In cerebellum the expression level did not change with age or by thyroid status. In situ hybridization revealed that ZAKI-4 mRNA is widely expressed in neurons throughout the brain. It is noteworthy that the expression in the neurons of layer VI of the cerebral cortex was more evident in control rats than that in hypothyroid rats from P17 to P30. Though not influenced by hypothyroidism, there were several regions of the brain in which ZAKI-4 mRNA was strongly expressed. These regions were the mitral cell layer of the olfactory bulb, the substantia nigra, and the hippocampus, where calcineurin is also abundantly expressed. Therefore, it may be hypothesized that ZAKI-4 plays an important role in the development and function of the brain by modulating calcineurin function; and decrease in ZAKI-4 mRNA expression in the specific brain areas may explain, in some parts, the mechanism of abnormal brain development by hypothyroidism.

Dissecting aneurysm of the peripheral posterior inferior cerebellar artery

Dissecting aneurysms of intracranial posterior circulation have recently been shown to be less uncommon than previously thought. However, those involving the posterior inferior cerebellar artery (PICA) and not vertebral artery at all are extremely rare. We report here a case of a patient with a dissecting aneurysm of the lateral medullary segment of PICA which presented as subarachnoid haemorrhage. The aneurysm was treated by trapping surgery and the distant PICA was anastomosed to the occipital artery. The patient showed a slight ataxia immediately after surgery but recovered fully. Recovery from immediately postoperative cerebellar symptoms due to intra-operative ischemia seemed to be due largely to recovery of flow in the region of cortical branches of PICA.

Spatiotemporal expression of BDNF in the hippocampus induced by the continuous intracerebroventricular infusion of beta-amyloid in rats

The beta-amyloid protein (Abeta) is the major component of senile plaques found in the brain in Alzheimer's disease (AD). Its neurotoxic properties in vivo, however, are not well defined. Since the expression of neurotrophin genes is considered an important component of the intrinsic neuroprotective response to insults, we analyzed the gene expression of neurotrophins in the brains of rats which received a continuous infusion of Abeta-(1-42) into the cerebroventricle. Northern blot analysis revealed a significant increase in brain-derived neurotrophic factor (BDNF) expression in the hippocampus but no change in the cerebral cortices. The alteration peaked on days 3-7 and returned to the basal level on day 14 after the start of Abeta-(1-42) infusion. No significant changes in nerve growth factor or neurotrophin-3 mRNA expression were observed. The infusion of Abeta-(1-40) and (25-35) also triggered the expression of BDNF mRNA, whereas neither Abeta-(40-1) nor (1-16) had any effect. In situ hybridization histochemistry revealed that the expression mainly occurred in the hilus and granular layer of the dentate gyrus and to a lesser extent in the pyramidal neurons of the CA1 region. These results demonstrate that the continuous intracerebroventricular infusion of Abeta induces selective and spatiotemporal expression of BDNF mRNA in the hippocampus.

Identification of a novel myosin-Va mutation in an ataxic mutant rat, dilute-opisthotonus

Mutations of the myosin-Va gene (Myo5a) cause diluted coat color in mice and are occasionally associated with severe neurological disorders. Dilute-opisthotonus (dop) is a spontaneous gene mutation in the rat, and phenotypes of the homozygote (dop/dop) are similar to those of the Myo5a-deficient mouse, suggesting that the mutation resides in the rat Myo5a gene. To elucidate the molecular basis of the dop mutation, we cloned the rat Myo5a cDNA from the wild type and the dop/dop. The wild-type rat Myo5a cDNA contained a 5487-bp ORF and showed higher homology with Myo5a of the other species than Myr6 (Myo5b) in the rat. A 141-bp in-frame deletion was detected in the head region in the dop cDNA. An intragenic rearrangement consisting of a 306-bp inversion associated with 17-bp and 217-bp deletions were identified in the Myo5a gene of the dop genome. This rearrangement involved a 141-bp exon, which was skipped in the dop transcript. The MyoVA protein expression was severely impaired in the dop/dop brain. This is the first report to define the dop mutation as the Myo5a gene abnormality in the rat.

Levels of hepatocyte growth factor and its messenger ribonucleic acid in uncomplicated pregnancies and those complicated by preeclampsia

The purpose of this study was to elucidate the possible relationship between hepatocyte growth factor (HGF) expression and the pathogenesis of preeclampsia. The concentration of immunoreactive HGF was measured and the expression of HGF messenger ribonucleic acid (mRNA) assessed in human placentas obtained from two groups: uncomplicated and preeclamptic pregnancies at various gestational weeks. In addition, the localization of HGF mRNA and c-met protein was analyzed using in situ hybridization and immunohistochemical staining, respectively. The expression of HGF mRNA and the concentration of immunoreactive HGF were highest in second trimester and were significantly decreased in preeclamptic placentas compared with the uncomplicated cases in third trimester. HGF mRNA was localized to placental mesenchymal cells, whereas c-met protein was demonstrated on cytotrophoblast. These results provide evidence of an abnormality of HGF expression in the preeclamptic placentas. Such placentas exhibit the abnormally shallow trophoblast invasion of the uterus, and reduced expression of HGF could well account for this morphometric change.

Molecular cloning of a novel thyroid hormone-responsive gene, ZAKI-4, in human skin fibroblasts

Utilizing a method called "differential display of mRNAs by means of polymerase chain reaction", the cDNA fragment of a thyroid hormone-responsive gene ZAKI-4 was cloned from cultured human skin fibroblasts. Northern blot analysis revealed that there were two ZAKI-4 mRNA species (3.4 and 1.4 kilobases (kb)), and they were up-regulated by a physiological concentration of triiodothyronine (T3). This T3 effect was abolished by the treatment with cycloheximide, indicating the possibility that gene ZAKI-4 is regulated by T3 in an indirect fashion, through an intermediate product of T3, rather directly by T3 itself. No effect of T3 on ZAKI-4 mRNA stability suggested that T3 induces the mRNA at the transcriptional level. Rapid amplification of cDNA ends confirmed the presence of two mRNA species. ZAKI-4 mRNA was detected in heart, brain, liver, and skeletal muscle but not in placenta, lung, kidney and pancreas. In skin fibroblasts and skeletal muscle, 3.4-kb mRNA was the major species, whereas 1.4-kb mRNA was dominant in heart, brain, and liver. The sequence analysis suggested that the two mRNA species arise from alternative polyadenylation and code a single protein of 192 amino acids. No homologous protein sequence was found in a data base. Elucidation of the function of ZAKI-4 gene product will provide new insights into an important role of T3 in various organs.

Mapping of the dilute-opisthotonus (dop) gene on chromosome 8 of the rat

The rat dilute-opisthotonus (dop) autosomal recessive gene, causing ataxia and coat color dilution, was mapped on chromosome 8 by PCR-amplified microsatellite markers. To facilitate the linkage analysis, an intersubspecific cross with a Japanese wild rat strain was used. The recombination frequencies were 12.8% between Apoc3 and dop, and 32.1% between dop and Mylc1v. The following order of three genes is proposed; Apoc3-dop-Mylc1v. This mutation appears to be homologous to dilute-lethal (d1) of the mouse in terms of clinical symptoms, coat color effect and chromosomal location of the gene loci. Key words: ataxic mutant rat, dilute-opisthotonus (dop), gene mapping.

[Experimental study on the cleft lip and palate. VIII. Induction of cleft palate in Wistar rats by vitamin A]

We tried to induce cleft palate in Wistar rats by injecting Vitamin A. We injected Vitamin A into the stomach of females when they were pregnant on the eighth, ninth, tenth and eleventh day. We them sacrificed them to observe the fetuses while they were still pregnant on the eighteenth-twentieth day. The results showed that a high rate of cleft palate could be induced by injecting 5-10 x 10(4) I.U/kg of Vitamin A during pregnancy on the tenth day.

[Epidemiological investigation of cleft lip and/or palate. II. Incidence of cleft lip and palate among Japanese babies in Gifu prefecture 1986 to 1987]

Since 1981 we have been conducting investigations in Aichi Prefecture where our institution is located in close cooperation with Medical Association of Obstetrics-Gynecologists and member physicians of the Midwives Association. In addition, we surveyed 111 institutions in Gifu Prefecture for the patient who was delivered from January 1, 1986 to December 31, 1987 to learn the incidence and type classification of cleft lip and/or palate in the general population Gifu. Consequently, we acquired the date of 20667 newborns. It was found as a result that 35 babies had these abnormalities and that ratio of the birth of such newborns was one for 590.5 deliveries. Among 35 cleft infants 12 (34.3%) with cleft lip and palate, 5 (14.3%) cleft palate. Looking at the estimates from the results of our investigation, the annual number of newborns with these disease in the Gifu Prefecture was 41.6 to 41.9 in 1986, 33.5 to 33.6 in 1987 with 95 percent confidence limits.