Left coronary cusp ablation to eliminate epicardial substrates – a novel strategy for left ventricular summit ventricular tachycardia ablation

Background

Catheter ablation of LV summit VT can be challenging due to possible subepicardial or intramural site of origin and its close proximity to the major coronary vessels.

Objective

Local electrograms monitoring inside LV summit communicating vein potentially defines arrhythmogenic substrates and facilitates ablation from the adjacent anatomical structures.

Results

We experienced two cases of LV summit VT with epicardial local abnormal ventricular activities (Epi-LAVA) recorded from distal bipolar electrode of the 2F microcatheter in communicating vein close to the superior portion of LV summit. During sinus rhythm, Epi-LAVA displayed isolated late fractionated potentials in the first case but had initial fractionated potentials fused with terminal portion of far-field ventricular signals and late isolated potentials exhibiting 2:1 conduction in the second case. Epi-LAVA represented earliest ventricular signals during VT in both cases. Pace mapping at Epi-LAVA sites yielded single QRS morphology with excellent pacemap score and induced VT. Our strategy was to perform ablation at the facing site of Epi-LAVA aiming to eliminate the potentials transmurally. Radiofrequency (RF) energy was applied above and under the left coronary cusp opposite to Epi-LAVA sites using 3.5-mm tip open-irrigation catheter with a power of 30–35 W for 60 seconds under real-time intracardiac echocardiograhic guidance. VT was slowed and terminated in 1 second. Repeat ablation delayed and completely abolished Epi-LAVA followed by noninducibility of VT. Anatomical proximity of the left coronary cusp semilunar insertion and subepicardial or intramural site of origin possibly dictates successful ablation. Epi-LAVA from coronary vein mapping serve as a new landmark of the ablation target with a measurable procedural endpoint.

Conclusion

Elimination of epicardial substrates with RF energy application at the left coronary cusp can be a novel strategy for LV summit VT ablation.

Funding Acknowledgement

Type of funding source: None

Changes in the skeletal dimensions of the digits of the thoracic limb of Holstein cows after maturation

The 12 left digits of the thoracic limb of Holstein female cows were obtained from a slaughterhouse, and 13 linear measurements of skeletal specimens of the digits of the thoracic limb were used in this study. Bivariate plots, regressions and correlation analyses were performed to assess the relationships between osteometric data and age, and between osteometric data and body size. The geometric mean (GM) of the metacarpal size was used as a proxy of body weight. The results of the regression analysis demonstrated that the length and the width of the distal phalanx were significantly correlated with age, whereas those of other bones were not. In addition, the correlations of the distal phalanx tended to be higher with age than with the GM of the metacarpal size, and their skeletal measurements tended to be longer in older animals than in younger animals. These findings suggest that the distal phalanx is slightly elongated and enlarged in its solear aspect with increasing age in skeletally mature cows. Moreover, although the side difference in the distal phalanx between the lateral and medial digits did not increase significantly with age, the solear aspect of the distal phalanx tended to be rougher, and deformation of the flexor tubercle tended to be more pronounced in the medial digit compared with the lateral digit. Therefore, in the distal phalanx of the front feet, the skeletal deformation with age and asymmetrical bone development might be related to the pathogenesis of claw horn lesions, as in the hind feet.

Multivariate analysis of variations in intrinsic foot musculature among hominoids

Comparative analysis of the foot muscle architecture among extant great apes is important for understanding the evolution of the human foot and, hence, human habitual bipedal walking. However, to our knowledge, there is no previous report of a quantitative comparison of hominoid intrinsic foot muscle dimensions. In the present study, we quantitatively compared muscle dimensions of the hominoid foot by means of multivariate analysis. The foot muscle mass and physiological cross-sectional area (PCSA) of five chimpanzees, one bonobo, two gorillas, and six orangutans were obtained by our own dissections, and those of humans were taken from published accounts. The muscle mass and PCSA were respectively divided by the total mass and total PCSA of the intrinsic muscles of the entire foot for normalization. Variations in muscle architecture among human and extant great apes were quantified based on principal component analysis. Our results demonstrated that the muscle architecture of the orangutan was the most distinctive, having a larger first dorsal interosseous muscle and smaller abductor hallucis brevis muscle. On the other hand, the gorilla was found to be unique in having a larger abductor digiti minimi muscle. Humans were distinguished from extant great apes by a larger quadratus plantae muscle. The chimpanzee and the bonobo appeared to have very similar muscle architecture, with an intermediate position between the human and the orangutan. These differences (or similarities) in architecture of the intrinsic foot muscles among humans and great apes correspond well to the differences in phylogeny, positional behavior, and locomotion.

Three-Dimensional Study of the Terminal Portion in Sprague-Dawley Rat Ejaculatory Ducts

In mammals, a pair of ejaculatory ducts exists in the urethra at the seminal colliculus. The detailed anatomical structures of the distal end of the ejaculatory ducts of Sprague-Dawley rats were investigated by the computer-assisted three-dimensional reconstruction analysis using light-microscopic serial sections. A three-dimensional reconstruction revealed that in adult rats, the ejaculatory sinus pair consists of two parts: the cranial section - a compartment region composed of a fusion of the ampullary gland duct and the seminal vesicle duct, and the caudal section - a grooved region composed of a long slitlike ejaculatory ostium that extends into the urethra on both sides of the seminal colliculus. But the sphincter structure was not observed. The long axis of the compartment region was approximately 58 μm in length, and that of the groove region was approximately 495 μm. Although many epithelial glands ducts were distributed throughout the ejaculatory sinuses, the prostate and coagulation gland ducts did not open in these sinuses. The urethra was composed of transitional epithelium, while the ejaculatory sinuses were composed of single to stratified cuboidal epithelium. The ejaculatory ducts continued to the ejaculatory ostium in male adult Sprague-Dawley rat were composed of the seminal vesicle ducts received the ampullary gland ducts.

Double Virus Vector Infection to the Prefrontal Network of the Macaque Brain

To precisely understand how higher cognitive functions are implemented in the prefrontal network of the brain, optogenetic and pharmacogenetic methods to manipulate the signal transmission of a specific neural pathway are required. The application of these methods, however, has been mostly restricted to animals other than the primate, which is the best animal model to investigate higher cognitive functions. In this study, we used a double viral vector infection method in the prefrontal network of the macaque brain. This enabled us to express specific constructs into specific neurons that constitute a target pathway without use of germline genetic manipulation. The double-infection technique utilizes two different virus vectors in two monosynaptically connected areas. One is a vector which can locally infect cell bodies of projection neurons (local vector) and the other can retrogradely infect from axon terminals of the same projection neurons (retrograde vector). The retrograde vector incorporates the sequence which encodes Cre recombinase and the local vector incorporates the "Cre-On" FLEX double-floxed sequence in which a reporter protein (mCherry) was encoded. mCherry thus came to be expressed only in doubly infected projection neurons with these vectors. We applied this method to two macaque monkeys and targeted two different pathways in the prefrontal network: The pathway from the lateral prefrontal cortex to the caudate nucleus and the pathway from the lateral prefrontal cortex to the frontal eye field. As a result, mCherry-positive cells were observed in the lateral prefrontal cortex in all of the four injected hemispheres, indicating that the double virus vector transfection is workable in the prefrontal network of the macaque brain.

Muscle dimensions of the foot in the orangutan and the chimpanzee

The hindlimbs of two orangutans and four chimpanzees were dissected, and muscle parameters (mass, fascicle length, and physiological cross-sectional area: PCSA) were determined to explore possible interspecies variation in muscle dimensions. Muscle mass and PCSA were divided by the total mass and total PCSA of the entire foot muscles for normalization. The results indicate that the pedal interosseous and the intrinsic pedal digital extensor muscles in the orangutans probably have higher capacity for force production due to their relatively larger PCSAs than in chimpanzees. Moreover, the medial components of the intrinsic muscles exhibited relatively larger mass and PCSA ratios in orangutans. The mass and PCSA ratios of the hallucal muscles were larger in chimpanzees. These differences in foot muscle dimensions of the two species suggest that the orangutan is more specialized for hook-like digital gripping without involvement of the rudimentary hallux, while the chimpanzee is adapted to hallux-assisted power gripping in arboreal locomotion.

Biochemical and developmental characterization of carbonic anhydrase II from chicken erythrocytes

BACKGROUND

Carbonic anhydrase (CA) of the chicken has attracted attention for a long time because it has an important role in the eggshell formation. The developmental profile of CA-II isozyme levels in chicken erythrocytes has not been determined or reported. Furthermore, the relations with CA-II in erythrocyte and egg production are not discussed. In the present study, we isolated CA-II from erythrocytes of chickens and determined age-related changes of CA-II levels in erythrocytes.

METHODS

Chicken CA-II was purified by a combination of column chromatography. The levels of CA-II in the hemolysate of the chicken were determined using the ELISA system in blood samples from 279 female chickens, ages 1 to 93 weeks, 69 male chickens, ages 3 to 59 weeks and 52 weeks female Araucana-chickens.

RESULTS

The mean concentration of CA-II in hemolysate from 1-week-old female was 50.8 ± 11.9 mg/g of Hb. The mean levels of CA-II in 25-week-old (188.1 ± 82.6 mg/g of Hb), 31-week-old (193.6 ± 69.7 mg/g of Hb) and 49-week-old (203.8 ± 123.5 mg/g of Hb) female-chickens showed the highest level of CA-II. The levels of CA-II in female WL-chickens significantly decreased at 63 week (139.0 ± 19.3 mg/g of Hb). The levels of CA-II in female WL-chicken did not change from week 63 until week 93.The mean level of CA-II in hemolysate of 3-week-old male WL-chickens was 78.3 ± 20.7 mg/g of Hb. The levels of CA-II in male WL-chickens did not show changes in the week 3 to week 59 timeframe. The mean level of CA-II in 53-week-old female Araucana-chickens was 23.4 ± 1.78 mg/g of Hb. These levels of CA-II were about 11% of those of 49-week-old female WL-chickens. Simple linear regression analysis showed significant associations between the level of CA-II and egg laying rate from 16 week-old at 63 week-old WL-chicken (p<0.01).

CONCLUSIONS

Developmental changes and sexual differences of CA-II concentration in WL-chicken erythrocytes were observed. The concentration of CA-II in the erythrocyte of WL-chicken was much higher than that in Araucana-chicken (p<0.01).

Accumulation of caveolin-3 protein is limited in damaged muscle in chicken muscular dystrophy

Members of the caveolin family are the main component of caveolae, and caveolin-3 is a muscle-specific protein. Caveolin-3 deficiency induces a muscular dystrophic phenotype, while its overexpression is also harmful to muscle cells. Increased caveolae were observed in chicken muscular dystrophy; however, the underlying mechanism causing the onset remains unclear. Therefore, the current study analyzes the expression of caveolin-3 and other caveola-related proteins in dystrophic chickens. Western blotting and semi-quantitative RT-PCR analysis revealed that (1) caveolin-3 is highly expressed in the damaged muscle of dystrophic chickens (7.12-fold); (2) the amount of caveolin-3 protein is regulated in posttranslational modification, since no significant increase is observed at the mRNA level (1.09-fold); and (3) the expression pattern of other caveola-related proteins is similar to that of caveolin-3. These results suggest that the accumulation of caveolin-3 protein may be associated with the causative process of chicken muscular dystrophy.

Pathomechanism of cellular infiltration in the perivascular region of several organs in SAMP1/Yit mouse

We investigated the histological changes of extra-intestinal organs, such as the liver, kidney, lung and pancreas in SAMP1/Yit mice, a human Crohn's disease model, using immunohistochemical techniques. The perivascular cellular infiltration was detected around the small vessels after 30 weeks. These infiltrating cells consisted of many CD4-positive T-lymphocytes, and small numbers of CD8- positive T-lymphocytes and IgG-positive B-lymphocytes. MAdCAM-1 and VCAM-1 were detected in vascular endothelial cells in non-affected regions of 13 and 20 week-old, as well as in the affected regions showing perivascular cellular infiltration after 30 weeks. In addition, integrin alpha4beta7 was detected on these infiltrating cells in the perivascular regions after 30 week-old. LT-beta and IL-12, cytokines of the Th-1-type immune response, were not observed in these affected regions. However, IL-4, one of the cytokines of the Th-2-type immune response, was detected on the perivascular infiltrating cells after 30 week-old. These results revealed that the changes in extra-intestinal organs were mainly caused by infiltration of CD4-positive T-lymphocytes into the perivascular regions in SAMP1/Yit mice. These cellular infiltrations were thought to be initiated by adhesion of CD4-positive T-lymphocytes to the endothelial cells mediated by MAdCAM-1 and integrin beta7. Immunohistochemistry for Th related cytokines indicated that the perivascular cellular infiltration was developed by the Th-2-type immune response in the extra-intestinal organs of SAMP1/Yit mouse.

Determination of full-length cDNA nucleotide sequence of equine carbonic anhydrase VI and its expression in various tissues

A full-length cDNA clone of an equine carbonic anhydrase (CA)-VI was obtained from the equine parotid gland. The cDNA sequence was 1338 bp long and was predicted to encode a 319 amino acid polypeptide with a putative signal peptide of 18 amino acids. The deduced amino acid sequence of mature CA-VI showed the similarity of 70% to those of other mammalians reported. Westernblot analysis using anti-horse CA-VI peptide detected the single band in parotid gland, and the band reduced its size by treatment with N-glycosidase F. Additionally, CA-VI protein expression was confirmed in submandicular gland and weakly in liver. In contrast, RT-PCR analysis revealed signals in the digestive tract including duodenum, jejunum, ileum, cecum and colon as well as the salivary glands. In addition, certain signals were detected in testis, thyroid gland and liver, but not in nerve tissue, skeletal muscle, spleen or lymph node.

Immunohistolocalization and gene expression of the carbonic anhydrase isoenzymes (CA-II and CA-VI) in glands associated with the canine lacrimal apparatus

Cytosolic and secretory carbonic anhydrase isoenzymes (CA-II and CA-VI, respectively) were detected by immunohistolocalization using specific canine CA-II and CA-VI antisera. CA-II and CA-VI were identified in glands associated with the canine lacrimal apparatus, such as lacrimal gland, superficial gland of the third eyelid (third eyelid gland) and tarsal gland. CA-II and CA-VI mRNA signals were also detected by reverse-transcriptase polymerase chain reaction in the same tissues. Some serous acinar cells and duct segments in the lacrimal gland and serous acinar cells in the third eyelid gland were immunopositive for anti-CA-II and CA-VI antisera. In particular, some immunopositive acini to CA-II and CA-VI on the edge of the third eyelid gland are histologically similar to sebaceous gland cells. Sebaceous gland cells in the tarsal and ciliary glands also showed immunopositivity to both CA antisera. CA-II and CA-VI gene transcripts were detected in the same regions. These results suggest that secreted CA-VI may form together with cytosolic CA-II, a high-activity isozyme mostly considered as a bicarbonate producer, in a mutually complementary system for the maintenance of bicarbonate levels to regulate pH in tear fluid and protect the corneal epithelia against injuries. In sebaceous gland cells in the lacrimal apparatus, CA-VI may be related to lipogenesis in an unknown function.

Dimensions of forelimb muscles in orangutans and chimpanzees

Eight forelimbs of three orangutans and four chimpanzees were dissected and the muscle mass, fascicle length and physiological cross-sectional area (PCSA) of all forelimb muscles were systematically recorded to explore possible interspecies variation in muscle dimensions. Muscle mass and PCSA were divided by the total mass and total PCSA of the entire forelimb muscles for normalization. The results indicate that the mass and PCSA ratios of the monoarticular elbow flexors (M. brachialis and M. brachioradialis) are significantly larger in orangutans. In contrast, the mass ratios of the biarticular muscles in the upper arm (the short head of M. biceps brachii and the long head of M. triceps brachii) are significantly larger in chimpanzees. For the rotator cuff muscles, the force-generating capacity of M. subscapularis is significantly larger in orangutans, whereas the opposite rotator cuff muscle, M. infraspinatus, is larger in chimpanzees. These differences in forelimb muscle dimensions of the two species may reflect functional specialization for their different positional and locomotor behaviors.

Dimensions of the foot muscles in the lowland gorilla

We dissected the hindlimb of a female western lowland gorilla and determined the muscle dimensions (mass, fascicle length, and physiological cross-sectional area: PCSA). Comparisons of the muscle parameters of the measured gorilla with corresponding reported human data demonstrated that the triceps surae muscles were larger and had more capacity to generate force than the other muscle groups in both species, but this tendency was more prominent in the human, probably as an adaptation to strong toe-off during bipedal walking. On the other hand, PCSAs of the extrinsic pedal digital flexors and digiti minimi muscles were larger in the western lowland gorilla, suggesting that the foot, particularly the fifth toe, has a relatively high grasping capability in the lowland gorilla.

Immunohistolocalization and gene expression of secretory carbonic anhydrase isoenzyme CA-VI in canine nasal cavity

Immunolocalization of the secretory form of carbonic anhydrase isoenzyme, CA-VI were studied using a specific canine CA-VI antiserum, and CA-VI mRNA signals were also investigated using the reverse-transcriptase polymerase chain reaction (RT-PCR) in canine nasal mucosal epithelia and glands. Immunoreactivity to CA-VI was positive throughout the mucosal epithelial cells and in the cytoplasm of serous acinar and ductal epithelial cells of the nasal mucosa and glands, including the vestibule of the nose, but the mucous acinar cells of the glands were immunonegative. We detected CA-VI gene transcripts in the same regions as the CA-VI immunoreactivity. The physiological roles of CA-VI in the nasal mucosal epithelium and glands might maintain bicarbonate levels in nasal secretions and protect the mucosa against acid.

A macroscopic examination of M. biceps femoris and M. gluteus maximus in the orangutan

The musculature of the hip and thigh in the orangutan has been described previously. Anatomically, there are various descriptions among primates in those structures, in particular, the relationship between M. biceps femoris and M. gluteus maximus, their derivatives, and the muscle segment. However, a detailed innervation system to this ischiofemoral part has not been described, thus there is still uncertainty as to with which muscle it is associated. In this analysis, we examined the gross anatomy of the hip and thigh muscles of the orangutan and chimpanzee, including their innervation. Also, a comparison was made with documented data of other primates. As a result of these observations, it was found that the ischiofemoral part in the orangutan is innervated by the same sciatic nerve branch (the common peroneal nerve) as the long head of M. biceps femoris, but not by the same nerve as M. gluteus maximus. Therefore, the ischiofemoral part is appropriately considered as a part of the long head of M. biceps femoris. It appears that this morphologic feature is an adjustment to the arboreal life of the orangutan. The development of the flexor complex of the thigh is necessary for this arboreal adaptation, resulting in a unique musculature of M. biceps femoris in the orangutan.

Comparative observation of skeletal-dental abnormalities in wild, domestic, and laboratory rabbits

Dietary habits must be considered as one of the major potential factors resulting in acquired malocclusions in rabbits. Although the dentition of the wild rabbit and the domesticated laboratory rabbit are basically identical, dietary habits are noticeably different. Therefore, the prevalence of tooth problems between these lagomorph species were investigated anatomically and radiographically. Mean measurements of the skull and dental arches suggested that wild rabbits have slightly shorter and wider skulls and dental arches compared with domestic laboratory rabbits. Root elongation of incisors and check teeth, and periodontal disease were more frequently observed in domestic laboratory rabbits. Diagnostic radiographs from domestic pet rabbits showed relatively higher crowns, severe root elongation, and advanced periodontitis. These results do not provide definitive evidence that dietary habits cause malocclusions, however they suggest that diet is a major factor in the initiation of malocclusions in rabbits.

Gene expression of secretory carbonic anhydrase isozymes in striated ducts of canine salivary glands using laser microdissection system

To clarify whether striated duct cells in canine salivary glands synthesize secretory carbonic anhydrase (CA-VI), as is the case with serous acinar cells, the present study utilized laser microdissection to harvest striated duct cells from canine parotid and submandibular glands, and total RNA extracted from these cells was then amplified by reverse transcription-polymerase chain reaction to assess CA-VI gene expression. The results confirmed the local expression of CA-VI mRNA in striated duct cells. This clarified that, in canine salivary glands, CA-VI is synthesized in not only serous acinar cells, but also striated duct cells.

The Time Course of Lymphatic Routes Emanating from the Peritoneal Cavity in Rats

The lymph drainage routes from the abdominal cavity in rats were observed at 3 min, 1, 2 and 4 h after India ink was administered intraperitoneally. Four systems of lymph drainage routes from the peritoneal cavity were observed. Three minutes after injection, the drainage route travelled via the intrathoracic lymph vessels located along the internal thoracic artery and returned to the anterior mediastinal lymph nodes. One hour after injection, the drainage route travelled via the lymph vessel located along the left phrenic nerve in addition to the drainage route observed at 3 min. Two and four hours after injection, in addition to the above-mentioned routes, the drainage that had travelled via the thoracic duct continued along the right side of the aorta and was also observed in the lateral lymph vessel located on the vertebra. These findings suggest that lymph or cells absorbed into the peritoneal cavity at first travel towards the anterior mediastinal lymph nodes in the thorax via the ventral lymphatic channels, and then gradually course through the dorsal lymphatic channels. These routes may serve as a route for transporting cancer cells and other cells from the peritoneal cavity.

Immunohistolocalization and Gene Expression of the Secretory Carbonic Anhydrase Isozymes (CA-VI) in Canine Oral Mucosa, Salivary Glands and Oesophagus

The immunohistolocalization of secretory carbonic anhydrase isoenzymes (CA-VI) in canine salivary glands, parotid, submandibular, sublingual and zygomatic glands, oral and oesophageal mucosa was studied using a specific antiserum against a canine CA-VI. In addition, the gene expression of CA-VI from the same tissue was studied using a real-time reverse-transcriptase polymerase chain reaction. In all salivary glands and oesophageal gland, immunostaining intensely localized CA-VI antiserum throughout the cytoplasm of serous acinar cells, including serous demilune and ductal epithelial cells. In contrast, no immunoreaction localized CA-VI in the mucous acinar cells of the gland. CA-VI gene transcripts were also detected in the same areas. The physiological significance of secretory CA-VI in the oral and oesophageal cavity is thought to play a highly specialized role in the maintenance of bicarbonate level in saliva and to protect mucosa from acid injury. It is shown that the major sites of the CA-VI secretion in dogs were in serous (demilune) secretory cells in all four major salivary glands and oesophageal glands in particular.

The time course of lymph drainage from the peritoneal cavity in beagle dogs

Lymph drainage routes from the abdominal and pelvic cavities in beagle dogs were observed serially by following the time course of India ink administered intraperitoneally. Four systems of lymph drainage routes from the peritoneal cavity were observed in this study. The earliest drainage returned to the cranial mediastinal lymph nodes via the sternal lymph vessels; subsequently, the sternal lymph nodes located along the internal thoracic artery became involved. Then, a drainage route via the lymph vessel along the left vagus nerve was observed. The final drainage route flowed into the lateral lymph vessel through the thoracic duct located on the vertebra. These results show that India ink is absorbed from the peritoneal cavity, and that the lymph drainage first flows mainly towards the cranial mediastinal lymph nodes through the ventral lymphatic channels. Our serial observations suggest that, over time, the lymph drainage routes changed from the ventral abdominal to the dorsal thoracic lymphatic channels in the thorax.

Measurement of Carbonic Anhydrase Isozyme VI (CA-VI) in Bovine Sera, Saliva, Milk and Tissues

Concentrations of bovine carbonic anhydrase isozyme VI (CA-IV) in bovine serum, saliva, normal milk, colostrum, submandibular gland, liver, and mammary gland were determined. CA-VI was purified from bovine saliva and an antibody to CA-VI was generated. The concentrations of CA-VI in the saliva (7.8 +/- 7.9 microg/ml), serum (2.1+/- 5.7 ng/ml), milk (7.9 +/- 12.1 ng/ml), submandibular gland (284.7 microg/g protein), liver (921.0 +/- 180.7 ng/g protein) and mammary gland (399.6 +/- 191.2 ng/g protein) were determined by ELISA. No seasonal change in CA-VI levels was observed in normal milk. The concentration of CA-VI in colostrum (day 1 post partum) was 119 ng/ml and decreased rapidly by 1 month following birth. Mammary gland contained much smaller amounts than the submandibular gland. CA-VI mRNA was detected in the liver and mammary gland of cow by RT-PCR. The ELISA used in this study proved to be a precise and sensitive method for determining CA-VI concentrations in saliva, serum, milk and tissue specimens from cows. The ELISA may enable the study of changes in CA-VI associated with hereditary or metabolic disorders of the salivary gland, mammary gland and liver using small samples of saliva, serum or milk.

Dopaminergic neuronal loss in transgenic mice expressing the Parkinson's disease-associated UCH-L1 I93M mutant

The I93M mutation in ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) was reported in one German family with autosomal dominant Parkinson's disease (PD). The causative role of the mutation has, however, been questioned. We generated transgenic (Tg) mice carrying human UCHL1 under control of the PDGF-B promoter; two independent lines were generated with the I93M mutation (a high- and low-expressing line) and one line with wild-type human UCH-L1. We found a significant reduction in the dopaminergic neurons in the substantia nigra and the dopamine content in the striatum in the high-expressing I93M Tg mice as compared with non-Tg mice at 20 weeks of age. Although these changes were absent in the low-expressing I93M Tg mice, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment profoundly reduced dopaminergic neurons in this line as compared with wild-type Tg or non-Tg mice. Abnormal neuropathologies were also observed, such as silver staining-positive argyrophilic grains in the perikarya of degenerating dopaminergic neurons, in I93M Tg mice. The midbrains of I93M Tg mice contained increased amounts of insoluble UCH-L1 as compared with those of non-Tg mice, perhaps resulting in a toxic gain of function. Collectively, our data represent in vivo evidence that expression of UCHL1(I93M) leads to the degeneration of dopaminergic neurons.

Macromorphometric study on ciliary body location in canine eyes

This macroscopic study firstly examined the precise locational information of the canine ciliary body, i.e., the ciliary crown and the ciliary ring in the beagle. The safe and effective transscleral laser photocoagulation technique requires the accurate location of the ciliary body. In both sides of the eyeball in 10 beagle dogs, the width of the ciliary ring and the distance from the limbus to the ciliary ring were measured with calipers using a stereomicroscope at the 8 points. The widest portion of ciliary body was found at the dorsal to ventro-temporal area of the lateral canthus (lateral portion of the eyelid; ear side). In contrast, the narrowest portion was seen at the ventro-nasal to nasal area of the medial canthus (medial portion of the eyelid; nasal quadrants). Use of transscleral photocoagulation at the present narrowest area of ciliary body may carry a high risk of destruction of the optic portion of retina.

Immunohistochemistry of the Bovine Secretory Carbonic Anhydrase Isozyme (CA-VI) in Bovine Alimentary Canal and Major Salivary Glands

In the present study, we firstly demonstrated immunohistochemical expressions of secretory carbonic anhydrase (CA-VI) isozyme in bovine forestomach, large intestine and major salivary glands. CA-VI was detected in basal layer epithelial cells of esophageal and forestomach stratified epithelium, in mucous cells of upper glandular region of large intestine, in serous acinar cells of the parotid gland, in serous demilune cells and some ductal liner cells of mandibular, monostomatic sublingual and esophageal glands. These immunohistolocalizations suggested that bovine CA-VI plays various roles in pH regulation, maintenance of ion and fluid balance, and cell proliferation.

Immunohistolocalization of Carbonic Anhydrase Isoenzymes (CA-I, -II and -III) in Canine Epididymis

The immunolocalization of the efferent duct and the epididymis in canine was firstly examined using an the immunohistochemical method with the canine carbonic anhydrase (CA) -I, CA-II and CA-III antisera. The efferent duct was immunonegative for all present canine CA antisera. However, some slender shaped epithelial cells in the head and body segments of the epididymal duct were intensely reacted to the CA-II antiserum. These results suggested that the CA-II might be controlled in the luminal environment in the head and body segments of the canine epididymis by the proton and bicarbonate balance for the maintenance of the spermatozoal stability and movement.

Identification and functional characterization of mouse TPO1 as a myelin membrane protein

TPO1 is a member of the AIGP family, a unique group of proteins that contains 11 putative transmembrane domains. Expression of the rat TPO1 gene is upregulated in cultured oligodendrocytes (OLs) during development from pro-oligodendroblasts to postmitotic OLs. However, the distribution of native TPO1 protein in cultured OLs and in the brain has not been elucidated. We investigated the distribution and cellular function of TPO1 in myelinating cells of the nervous system. In mice, TPO1 gene expression was detected in the central (CNS) and peripheral (PNS) nervous systems and was markedly upregulated at postnatal days 10-20, an early phase of myelination in the mouse brain. To investigate TPO1 localization, we generated affinity-purified antibodies to synthetic peptides derived from mouse TPO1. Immunohistochemical analysis showed that TPO1 was expressed in OLs and Schwann cells but not in neurons and astrocytes. Schwann cells from trembler mice, which lack PNS myelin, had significantly decreased TPO1 expression and an altered localization pattern, suggesting that TPO1 is a functional myelin membrane protein. In OL lineage cell cultures, TPO1 was detected in A2B5+ bipolar early progenitors, A2B5+ multipolar Pro-OLs, GalC+ immature OLs and MBP+ mature OLs. The subcellular localization of TPO1 in OL lineage cells was mapped to the GM130+ Golgi in cell bodies and Fyn+ cell processes and myelin-like sheets. Furthermore, TPO1 selectively colocalized with non-phosphorylated Fyn and promoted Fyn autophosphorylation in COS7 cells, suggesting that TPO1 may play a role in myelin formation via Fyn kinase activation in the PNS and CNS.

Volumetric perfusion CT using prototype 256-detector row CT scanner: preliminary study with healthy porcine model

This is a preliminary demonstration of volumetric perfusion CT of the brain in domestic pigs by using a prototype 256-detector row CT. Scan range is approximately 100 mm in the craniocaudal direction with 0.5-mm section thickness. The 256-detector row CT is an easily available imaging technique that can provide volumetric cine imaging, CT angiography, and perfusion CT in a wide craniocaudal coverage simultaneously.

A new mouse model for infantile neuroaxonal dystrophy, inad mouse, maps to mouse chromosome 1

Infantile neuroaxonal dystrophy (INAD) is a rare autosomal recessive hereditary neurodegenerative disease of humans. So far, no responsible gene has been cloned or mapped to any chromosome. For chromosome mapping and positional cloning of the responsible gene, establishment of an animal model would be useful. Here we describe a new mouse model for INAD, named inad mouse. In this mouse, the phenotype is inherited in an autosomal recessive manner, symptoms occur in the infantile period, and the mouse dies before sexual maturity. Axonal dystrophic change appearing as spheroid bodies in central and peripheral nervous system was observed. These features more closely resembled human INAD than did those of the gad mouse, the traditional mouse model for INAD. Linkage analysis linked the inad gene to mouse Chromosome 1, with the highest LOD score (=128.6) at the D1Mit45 marker, and haplotype study localized the inad gene to a 7.5-Mb region between D1Mit84 and D1Mit25. In this linkage area some 60 genes exist: Mutation of one of these 60 genes is likely responsible for the inad mouse phenotype. Our preliminary mutation analysis in 15 genes examining the nucleotide sequence of exons of these genes did not find any sequence difference between inad mouse and C57BL/6 mouse.

Measurement of Erythrocyte Carbonic Anhydrase Isozymes (CA-I and CA-II) in Racehorses and Riding Horses

Equine carbonic anhydrase isozymes (CA-I and CA-II) were purified from erythrocytes by several column chromatography. Polyclonal anti-CA-I and anti-CA-II sera were produced in rabbits. Sensitive competitive enzyme-linked immunosorbent assays (ELISA) were established to determine the developmental changes in CA-I and CA-II levels in equine erythrocytes. Concentrations of CA-I and CA-II in erythrocytes from 150 clinically normal thoroughbreds (123 racehorses and 27 riding horses) were determined by ELISA. Mean (+/- SD) concentrations of CA-I and CA-II in racehorses were 1.70 +/- 0.48 and 0.94 +/- 0.13 mg/g hemoglobin (Hb), respectively. Mean concentrations of CA-I and CA-II in riding horses were 2.34 +/- 0.52 and 0.76 +/- 0.08 mg/g Hb, respectively. When the CA levels in racehorses and riding horses were compared, the CA-I level in riding horses was higher than that in racehorses (p=0.01). The CA-II level in racehorses was higher than that in riding horses (p=0.02). These data suggest that the levels of CA isozymes in erythrocytes of racehorses were influenced by chronic physical stress. The CA-I concentration in erythrocytes of 2-month-old horses was approximately 0.25 mg/g Hb. The CA-I level noticeably increased during the first year of life and approached normal adult levels by 2 years. The CA-II level decreased slightly with age, indicating different regulation of CA-I and CA-II expression during development.

Histological and ultrastructural features in the early stage of Purkinje cell degeneration in the cerebellar calcification (CC) rat

The cerebellar calcification (CC) rat is a new neurodegenerative mutant with severe Purkinje cell loss and symmetrical calcifications in the cerebellar cortex manifesting ataxia: lack of coordination in body movements. In the present study, histopathological features were examined in the Purkinje cell degeneration in postnatal homozygous suckling rats without clinical signs, which were genotyped by microsatellite markers. In addition, the calcified Purkinje cells were investigated ultrastructurally and elemental analysis was performed on the deposits. Body weight of the homozygous (cc/cc) rats was already slightly lower compared with the heterozygotes (cc/+) in the neonatal stage. The degeneration of the Purkinje cells in the cc/cc rats was recognized obviously in lobules VI, VII, VIII and IX from 14 days after birth, a few days before the appearance of the ataxic behavior. The Purkinje cells in the region along the fissure between the VIII and IX lobule areas were intensely positive for periodic acid-Schiff reaction specific to glycoconjugates, and in this region, calcium depositions were weakly positive for von Kossa's stain. Electron microscopy also revealed that the calcified Purkinje cells possessed numerous electron-dense bodies containing inclusions with cystic structures such as vesicles, mitochondria and lysosomes, and these bodies were mainly composed of calcium and phosphorous. These findings suggest abnormal storage of glycoconjugates might be a trigger of Purkinje cell degeneration and serves as a matrix for accumulation of calcium phosphate in the cerebellum of CC rats.

Distributional changes of BrdU, PCNA, E2F1 and PAL31 molecules in developing murine palatal rugae

The distribution of cells incorporating bromodeoxyuridine (BrdU) and the expression of molecules involved in the control of cell proliferation (proliferating cell nuclear antigen [PCNA], a cellular factor in F9 teratocarcinoma cells that recognizes an adenovirus E1A inducible promoter 1 [E2F1] and proliferation-related acidic nuclear protein 31 [PAL31]) during morphogenesis of the murine palatine rugae (PR) was examined histochemically. Pattern formation of the PR rudiment was initiated with cell cycle related molecules in the epithelium of the primary palate. Cells which had incorporated BrdU were detected at the outer areas of the presumptive epithelial placode (EP) and the EP at 11.5-13.5 days post coitum (dpc) and the outer areas of the PR protrusion after 14.5 dpc. The number of PCNA-positive cells at the central area of the PR protrusion decreased after 16.5 dpc. E2F-positive cells were detected at the outer areas of the PR protrusion at 15.5 and 16.5 dpc. The number of PAL31-positive cells at the presumptive EP area and the already-formed EP area was decreased at 11.5-13.5 dpc. In two dimensional histological reconstructions, PAL31 expression approximately corresponded to the distribution of BrdU-positive cells at 11.5 and 13.5 dpc. EP placode formation might be regulated by spatiotemporal cell proliferation control involving the expression of the PAL31 molecule. Following EP formation, PR development and growth control involved the expression of E2F1 and PCNA molecules.

Nucleotide sequence and expression of a cDNA encoding canine carbonic anhydrase VI (CA-VI)

A full-length cDNA clone of a canine carbonic anhydrase VI (CA-VI) was generated from the canine parotid gland by using a reverse transcription-polymerase chain reaction (RT-PCR) technique with degenerate primers designed from conserved regions of the same locus in humans and bovines employing RACE (rapid amplification of cDNA ends) techniques. The cDNA sequence was 1351 base pairs (bp) long and was predicted to encode a 320-amino-acid polypeptide containing a putative signal peptide of 17 amino acids. The deduced amino acid sequence of mature CA-VI showed the highest similarity of 74% to that of human CA-VI. RT-PCR analysis with primers specific to the canine CA-VI demonstrated strong signals in the major salivary glands and weak signals in the minor salivary glands and esophagus of a healthy dog. No CA-VI mRNA was detected in the pancreas, liver or the digestive tract except the esophagus.

Cleavage line patterns in beagle dogs: as a guideline for use in dermatoplasty

We prepared a map of the cleavage lines for beagle dogs, as a guideline for use of cleavage lines in dermatoplasty. The cleavage lines at the head resembled the orientation of the underlying muscles. Although the cleavage lines in the trunk were perpendicular to the body axis, those in the thoraco-abdominal region were parallel to the body axis. The cleavage lines at the limbs were parallel to the long axis of the limb on the cranial surface, but were perpendicular to the long axis of the limb on the lateral and caudal surfaces. Also, we recorded in detail the cleavage lines in the distal regions of the limbs.

Postnatal development of the mouse volatile papilla taste bud cells

In the present study, we examined specific markers for taste bud cells in the mouse and the postnatal development of volatile papilla taste bud cells in ddY mice. We examined the immunoreactivity of 4 types of carbonic anhydrase isoenzymes, CA I, CA II, CA III and CA VI, as specific markers for taste bud cells, and K8.13 cytokeratin antibody as a specific marker for the lingual epithelial cells. Of the carbonic anhydrase isoenzymes, only CA III immunoreactivity was clearly detected in the spindle shaped gustatory cells. CA VI immunoreactivity was detectable in suspentacular cells. CA I and CA II antibodies did not recognize any taste bud cell specifically. K8.13 cytokeratin immunoreactivity was detected in the lingual epithelial cells, but not in taste bud cells. At 7 days after birth, the suckling phase, very small taste buds developed from the anaplastic gustatory cells. At 14 days after birth, the taste buds showed larger size than those at 7 days after birth. At 21 days birth, after the weaning phase, taste bud structure approximated the mature structure. These results demonstrate the specificity of anti-CA III and anti-CA VI for gustatory cells and suspentacular cells, respectively. These markers should be useful for an analysis of taste bud development in mice.

Immunohistolocalization of Carbonic Anhydrase Isozyme (CA-VI) in Bovine Mammary Glands

The localization of bovine carbonic anhydrase isozyme VI (CA-VI) was examined immunohistochemically in bovine mammary glands during early lactation period (after 2-3 days of postpartum) and dry period (at about 2 months preparturition in adults), and young calves (at 30 and 150 days after birth) using specific CA-VI antiserum. The immunoreaction for anti-CA-VI antiserum was very weak in the mammary glands in young (prepubescent) calves. In dry period, CA-VI was also weakly expressed in secretory epithelial (acinar) and ductal cells. In contrast, the reaction was intense in mammary gland cells in early lactation period. Dot blotting analysis indicated that anti-CA-VI reacted positively to beastings and mature saliva, but weakly or not at all to milk during the dry period or calf saliva, respectively. The intense expression of CA-VI in the mammary glands in early lactation period might compensate for low levels of secretion from functionally and structurally immature salivary glands in young calves.

Quality control system for mass screening in Japan

Japan was the first country to establish a nationwide quality control system. When the Japanese Federal Government initiated Nationwide Neonatal Screening in 1977, the system officially included a Quality Control (QC) System that should cover all screening laboratories in Japan. This QC system is quite different from that for usual clinical chemistry. The aim of the National QC System for Neonatal Screening is evaluation of the accuracy of the tests and evaluation of the ability to detect suspicious samples with very mild abnormalities. For accomplishing the aim, the QC center established an inter-laboratory QC survey Screening laboratories having weak points can be identified through the inter-laboratory QC survey, and the Center must find a way to improve the ability of these screening laboratories. This requires a nationwide consensus regarding the cut-off levels of tested materials. Based on the cooperation of the Societies For Mass-screening, of Inborn Errors of Metabolism and of Pediatric Endocrinology, we set low cutoff levels for each compound to minimize the number of false negative cases. The system also included the evaluation of the quality of essential screening reagents and the special filter paper for blood collection (in partnership with the production companies). For this purpose, we developed some new methods for evaluating the standard-compounds for the various screening tests exactly, except in the case of TSH screening.

Distribution of apoptotic cells and apoptosis-related molecules in the developing murine palatine rugae

Distribution of apoptotic cells and expression of the apoptosis-related factors p53, bcl-2 and bad during morphogenesis of the murine palatine rugae (PR) were examined histochemically using the terminal deoxynucleotidyl transferase-mediated UTP nick end-labeling (TUNEL) technique and specific antibodies against apoptosis and cell cycle-related molecules. Formation of the PR rudiment was controlled by cell proliferation and apoptosis in the palatal epithelium. TUNEL-positive cells were detected only at the epithelial placode area at 12.5-13.5 days post coitus (dpc), but only a few cells were positive at the protruding PR area at 14.5-16.5 dpc. Bcl-2 protein was expressed mainly in the areas outside of those containing TUNEL-positive cells at 15.5 -6.5 dpc. P53 protein was not detected throughout gestation. Bad was detected in the epithelial layer at 13.5 and 15.5 dpc and overlapping the apoptotic area at 13.5-15.5 dpc. Apoptosis of palatal epithelial cells might therefore involve spatiotemporally regulated expression of bad during murine PR development.

Characterization and purification of polymorphic arylalkylamine N-acetyltransferase from the American cockroach, Periplaneta americana

We separated two forms of arylalkylamine N-acetyltransferase (AANAT) from various organs of the American cockroach, Periplaneta americana. Both forms of the enzyme had an equivalent molecular mass of 28 kDa. One form isolated from the testicular accessory glands had high enzyme activity at acidic pHs. The isoelectric point was 5-6 and the substrate specificity was wider than the other type. The other isolated form from female midguts had a higher level of enzyme activity at basic pHs. These findings suggested that P. americana contains polymorphic AANAT, as is the case in Drosophila melanogaster. These forms differed not only in pH specificity, and substrate specificity but in chromatographic behavior and kinetic properties. Most of the organs we examined contained a mixture of the two forms since two types of AANAT activity were separated in different chromatographic fractions when two pH conditions were used for activity measurement.

Immunohistochemical localization of carbonic anhydrase isoenzymes in salivary gland and intestine in adult and suckling pigs

Localizations of carbonic anhydrase isoenzymes (CA I, CA II and CA III) were investigated immunohistochemically in the salivary glands and intestine of mature and suckling pigs. Carbonic anhydrase isoenzymes were not detected in the salivary glands of sucklings, but were present in the adult. Bicarbonate ion in saliva might be important for the digestion of solid foods in mature pigs, but unnecessary for the digestion of milk in sucklings. Expressions of CA I and CA II were detected strongly in the large intestine of the adult and sucklings, and faintly only at duodenum in the small intestine. CA I and CA II isoenzymes in the large intestine may be involved, at least in part, in ion absorption and water metabolism during digestion and absorption of milk in suckling pigs. In addition, CA I and CA II expression in the duodenal villus enterocyte may support the process of bicarbonate absorption in the duodenum.

[An assessment of dysphagia using videofluorography in Parkinson's disease and progressive supranuclear palsy]

We assessed the oropharyngeal swallowing ability in 8 patients with Parkinson's disease (PD), 8 patients with progressive supranuclear palsy (PSP), and 10 age-matched healthy controls (CTL) using videofluorography (VF). In VF studies, PD and PSP patients demonstrated food pooling on the tongue, difficulty in bolus formation, and bolus falling into pharynx before swallow. PSP patients had a significantly longer delay in the pharyngeal phase and showed food falling into larynx more often than PD patients (p < 0.05). On measurement of swallowing time periods as proposed by Robbins et al., both patient groups showed significantly longer periods during many swallowing phases (P < 0.05) compared to those in the control group, but there were no significant differences between the PD and PSP groups. However, in PSP patients, the time for "transferring the food bolus from the oral cavity to pharynx" which we defined as a distinct stage was significantly longer (p < 0.05) than that in the PD group. We think that the difference in dysphagia characteristics between the two diseases arises from the variations in pathological changes in PSP, including those in the cerebral cortex, cerebellum, pons and medulla tegmentum in addition to the basal ganglia. Dystonia in the neck muscle also plays a role in dysphagia in PSP patients. Levodopa medication, changing the form of foods and training in rehabilitation techniques such as the chin down posture, supraglottic swallowing and ice-massage of the oral region are probably effective for dysphagia in PD patients. In patients with PSP, there are few research reports about the treatment of dysphagia. However, several dysphagia treatments seem to be useful depending on the abnormal patterns in the VF. Further studies are necessary to establish more effective treatments for dysphagia in PD and PSP.

Distribution of carbonic anhydrase isozyme VI in the developing bovine parotid gland

The distribution of bovine carbonic anhydrase isozyme VI (CA-VI), purified from bovine saliva, was studied immunohistochemically using antiserum against bovine CA-VI in bovine parotid glands during fetal and postnatal development. A weak expression of CA-VI in undifferentiated epithelial cells and ductal cells was observed in a 4- to 5-month-old fetus with a 26-cm crown-rump length. The reaction in both acinar and ductal cells subsequently persisted during late gestation and birth. Although anti-CA-VI reactivity was still seen in both regions immediately following birth, the reactivity had almost completely disappeared from most duct segments by 1 month following birth. Changes in the localization and time-dependent expression of the isozyme in parotid glands may reflect changes in the biological function of structurally closely related isozymes.

[A case of amyotrophic lateral sclerosis presenting with circulatory collapse during artificial respiration]

A 71-year-old man developed dysarthria and difficulty of swallowing in December 1997. He was diagnosed as having the bulbar type of amyotrophic lateral sclerosis (ALS). In November 1998, he was admitted to our hospital to undergo treatment for bulbar palsy and respiratory discomfort. In January 1999, ventilatory support (synchronous intermittent mandatory ventilation) during sleep at night was initiated. Severe progressive hypotension and loss of consciousness were observed soon after the start of artificial respiration, and both symptoms disappeared after artificial respiration was discontinued. This phenomenon was observed consistently during ventilatory support, while unpleasant stimuli such as bronchoscopy and replacement of the cannula tube induced severe hypertension. To clarify the mechanism of underlying these abnormal changes in blood pressure, autonomic function tests were performed while awake during the daytime. Ventilatory support induced a drop in blood pressure accompanied by a decrease in influx speed to the right ventriculum, the latter of which suggested a reduction in venous return. These values returned to the baseline following detachment of the ventilator. A 60 degrees head-up tilt (HUT) angle and standing from a supine position produced orthostatic hypotension, the latter of which was accompanied by a compensatory increase in pulse rate. The basal supine plasma noradrenaline (NA) level was high and the HUT showed a slight elevation of NA. The basal supine plasma arginine vasopressin (AVP) level was within the normal range, whereas the AVP level did not increase during HUT. Urinary secretion rates of NA and 3-methoxy-4-hydroxy-phenylglycol were elevated. A cold pressor test demonstrated reflex hypertension. The oculovagal reflex, coefficient of variation of R-R intervals. (CVR-R) and increase in pulse rate in response to atropine administration were within the normal range. The combination of midodrine, L-dihydroxyphenylserine (DOPS) and increasing intravascular volume via continuous intravenous drip infusion relieved the circulatory collapse during artificial respiration. In conclusion, the present case of ALS had sympathetic hyperactivity, somatosympathetic reflex and dysregulation of the baroreflex arc. Degeneration of central autonomic network, including the hypothalamus and the central nucleus of the amygdala, which has been shown in some ALS patients, might underlie the autonomic abnormalities in this patient.

Protective effects of murine recombinant interferon-beta administered by intravenous, intramuscular or subcutaneous route on mouse hepatitis virus infection

The significance of the route for administration of murine recombinant interferon-beta (IFN-beta) for inducing its therapeutic effects has been studied. BALB/c mice were daily injected intravenously, intramuscularly or subcutaneously with 1.5x10(3), 1. 5x10(4), or 1.5x10(5) IU of IFN-beta, from one day before to 8th day after mouse hepatitis virus (MHV-2) challenge. All mice received IFN-beta survived significantly longer than those without IFN. In the liver of those IFN-treated mice, viral growth and the histopathological damages were extremely alleviated. These results suggest that, irrespective of the differences in the route of administration, IFN-beta markedly suppressed viral activity when its administration was started prior to viral infection. For clinical use, however, further studies are needed on the optimal route for administration if IFN-beta is given after viral infection.

Afferent and efferent excitabilities of the transcortical loop in patients with dentatorubral-pallidoluysian atrophy

To evaluate the excitabilities of the transcortical loop in patients with dentatorubral-pallidoluysian atrophy (DRPLA), we studied somatosensory evoked potentials (SEPs) and evoked EMG responses (V1 and V2) in 10 patients and age-matched controls. In addition, the facilitatory effects of somatosensory inputs on motor evoked potentials (MEPs) were studied in four patients and controls. We observed attenuated or prolonged cervical and subcortical potentials and prolonged middle latency components of SEPs. The amplitudes of V2 in patients were significantly lowered compared to those in the controls, while the amplitudes and latencies of V1 were similar between the two groups. Since V2 was considered as a transcortical reflex, our results suggest reduced excitabilities of the afferent pathway of the transcortical loop in patients with DRPLA. Median nerve stimulation (MNS) 25 to 30 ms preceding transcranial magnetic stimulation (TMS) facilitated MEPs in the thenar muscle in two of the four patients and in the controls. The facilitation of MEPs by MNS tended to be independent of the reduction in V2. Such a result suggests that different neural mechanisms elicit V2 and facilitate MEPs following peripheral nerve stimulation, although further studies are needed. The combination of SEPs, evoked EMG responses and MEPs may be a useful technique to detect abnormalities of input and output coordinations of the transcortical loop.

Immunohistochemistry of carbonic anhydrase isozymes (CA-I, II and III) in canine salivary glands: a distributional and comparative assessment

The immunohistolocalization of carbonic anhydrase isozymes (CA-I, II, III) in canine salivary glands was studied using antiserum against CA-I, II, III. In parotid glands, immunostaining intensely localized cytosolic CA-II antiserum throughout the cytoplasm of acinar secretory cells and ductal epithelial cells, especially in the striated duct region. CA-III reactivity in the glands was only seen selectively at the intercalated ductal cells. In contrast, no immunoreaction localized CA-I in the gland. In the submandibular and sublingual glands, CA-I, II, and III were all observed in the ductal segments of the glands, whereas serous demilune appeared devoid of all three cytosolic CA isozymes. In contrast, in zygomatic glands (i.e. dorsal buccal glands) all CA isozymes were observed in both serous demilune and ductal segments. In all of the salivary glands examined, no mucous acinar cells were found to be reactive for any CA.

Influence of spironolactone on neonatal screening for congenital adrenal hyperplasia

AIM

To determine if the diuretic spironolactone cross reacts with 17alpha-hydroxyprogesterone (17OHP) in an enzyme linked immunosorbent assay (ELISA) kit used for the mass screening of congenital adrenal hyperplasia.

METHODS

Concentrations of 17OHP on a blood filter paper disc were measured using an ELISA kit (kit C-7: ENZAPLATE N-17alpha -OHP-7; Chiron, Tokyo, Japan). The cross reactivity of spironolactone and its metabolites with 17OHP was determined. The concentrations of spironolactone and its metabolites in blood were measured using HPLC (high performance liquid chromatography).

RESULTS

Spironolactone cross reacted with 17OHP using kit C-7 (0.01%), by increasing 17OHP concentration in a dose dependent manner. The blood concentration of spironolactone and its metabolites was nearly 900 ng/ml, high enough to show an additive effect on the 17OHP concentration. About 12% of the false positive cases screened using the kit were due to the administration of spironolactone.

CONCLUSIONS

Spironolactone interferes with 17OHP concentrations, leading to false positive test results for CAH.