Estimating the total length of Mekong giant catfish, Pangasianodon gigas, in an aquarium via stereo-video shooting and direct linear transformation

The Mekong giant catfish (MGC), Pangasianodon gigas, is one of the world's largest catfish species. Endemic to the Mekong River system, the MGC is critically endangered. Six MGC were transported from Thailand to the Gifu World Freshwater Aquarium (GWFA) in Japan in May 2004. The MGC have not been measured since they were introduced to the GWFA due to the challenges associated with their large size. Traditional methods, such as anesthesia and net-capture, could harm the fish, potentially reducing the population further. However, understanding the ecology of the species is essential to conservation efforts. Seasonal feeding rhythms and long-term fasting were previously observed in captive MGCs. To investigate the effect of long-term fasting on MGC growth, total length measurements are necessary. In this study, we applied a noncontact method to estimate the total length via image analysis. We shot a stereo-video of free-swimming MGC in the aquarium tank using two digital video cameras and analyzed the 3D images using the direct linear transformation method. We successfully estimated the total length of each MGC individual without contacting the fish. This accurate estimation method is versatile, simple, and useful in aquarium breeding and is also recommended from the viewpoint of animal welfare because it is a noninvasive method of measurement.

Experience-dependent learning of behavioral laterality in the scale-eating cichlid Perissodus microlepis occurs during the early developmental stage

Behavioral laterality-typically represented by human handedness-is widely observed among animals. However, how laterality is acquired during development remains largely unknown. Here, we examined the effect of behavioral experience on the acquisition of lateralized predation at different developmental stages of the scale-eating cichlid fish Perissodus microlepis. Naïve juvenile fish without previous scale-eating experience showed motivated attacks on prey goldfish and an innate attack side preference. Following short-term predation experience, naïve juveniles learned a pronounced lateralized attack using their slightly skewed mouth morphology, and improved the velocity and amplitude of body flexion to succeed in foraging scales during dominant-side attack. Naïve young fish, however, did not improve the dynamics of flexion movement, but progressively developed attack side preference and speed to approach the prey through predation experience. Thus, the cichlid learns different aspects of predation behavior at different developmental stages. In contrast, naïve adults lost the inherent laterality, and they neither developed the lateralized motions nor increased their success rate of predation, indicating that they missed appropriate learning opportunities for scale-eating skills. Therefore, we conclude that behavioral laterality of the cichlid fish requires the integration of genetic basis and behavioral experiences during early developmental stages, immediately after they start scale-eating.

Fine-scale genetic structure of the endangered bitterling in the middle river basin of the Kiso River, Japan

Recently, anthropogenic alterations have had severe and negative impacts on the terrestrial and aquatic species and environments. To conserve species that have a small and limited habitat, it is necessary to focus on fine-scale population structure and its effects on persistence. The deepbodied bitterling Acheilognathus longipinnis is an endangered freshwater fish that occupies ponds scattered in lateral bars in the Kiso River. In this study, we conducted multi-locus microsatellite DNA analysis to evaluate both fine-scale population structure and genetic diversity, in order to conserve A. longipinnis. The smaller number of loci deviating from the Hardy-Weinberg equilibrium in ponds scattered in individual lateral bars compared to the whole river system suggests that A. longipinnis forms a local breeding population in units of ponds. The population was roughly split between the river banks and the local population located in ponds in the mid-channel bar showed intermediate relationships with the river bank populations. Gene flow between local populations was not always homogeneous and was not influenced by geographical distances between local populations or the direction of river flow. The dispersal of A. longipinnis across both river bank sides may be constrained and is probably affected by the ecological characteristics of A. longipinnis and the hydrological regimes. Consequently, A. longipinnis in the Kiso River is maintained as a complex of multiple local populations with appropriate gene flow among them. To conserve A. longipinnis, both the persistence of the unstable ponds and moderate genetic exchanges by individual migration are required.

Gut Morphometry Represents Diet Preference to Indigestible Materials in the Largest Freshwater Fish, Mekong Giant Catfish (Pangasianodon gigas)

The Mekong giant catfish Pangasianodon gigas is one of the largest freshwater fish, measuring up to 3 m in total length. This study was designed to determine the feeding habits of P. gigas to better understand how the fish achieve their large body size. We compared the relationship between gut length (GL) and total length (TL) among related species in superfamily Bagroidea, order Siluriformes (Pangasianodon hypophthalmus and Hemibagrus nemurus) in the Kaeng Krachan reservoir, Thailand. The mean relative gut length (RGL = GL / TL) of P. gigas was 3.50, showing that they have relatively long guts, with values more similar to those of omnivorous P. hypophthalmus (RGL = 3.70) than to those of carnivorous H. nemurus (RGL = 0.92). In the allometric relationship (i.e., log₁₀ GL = log₁₀ a + b log₁₀ TL), the slope close to 1 for P. gigas (b = 1.07) has been widely observed in carnivores, while P. gigas has a greater intercept of the linear equation than P. hypophthalmus and H. nemurus, resulting in a similar GL of P. gigas to omnivorous P. hypophthalmus at approximately 35 cm in TL. Moreover, GL of P. gigas at 150 to 250 cm in TL showed great variations (RGL = 1.35-6.32). The variation in RGL for P. gigas seemed to result from a poor nutritional state. In conclusion, P. gigas is suggested to feed on indigestible materials such as plants, algae, and sediments, and potentially experience fasting in a reservoir.

A key metabolic gene for recurrent freshwater colonization and radiation in fishes

Colonization of new ecological niches has triggered large adaptive radiations. Although some lineages have made use of such opportunities, not all do so. The factors causing this variation among lineages are largely unknown. Here, we show that deficiency in docosahexaenoic acid (DHA), an essential ω-3 fatty acid, can constrain freshwater colonization by marine fishes. Our genomic analyses revealed multiple independent duplications of the fatty acid desaturase gene Fads2 in stickleback lineages that subsequently colonized and radiated in freshwater habitats, but not in close relatives that failed to colonize. Transgenic manipulation of Fads2 in marine stickleback increased their ability to synthesize DHA and survive on DHA-deficient diets. Multiple freshwater ray-finned fishes also show a convergent increase in Fads2 copies, indicating its key role in freshwater colonization.

Seasonal feeding rhythm associated with fasting period of Pangasianodon gigas: long-term monitoring in an aquarium

The Mekong giant catfish Pangasianodon gigas is endemic to the Mekong River basin, and is recognized as endangered species, largely due to overfishing and development of the river basin. We monitored food intake of P. gigas in a stable environment in an aquarium over a 6-year period and analyzed their feeding rhythm and fasting periods. The daily food intake for each fish was recorded from 18 June 2004 to 17 June 2010. The feeding rhythm or pattern was determined by the fast Fourier transform (FFT) analysis. The FFT analysis revealed that different cycles of feeding rhythm (168.8, 313.1, and 365.3 days) in three catfishes and no observable cycles in two catfishes. However, three catfishes showed subordinate peaks with approximately 365 days (365.3 days for all). These suggest that, at least, four of five catfish had have approximately 365-days feeding cycle. We also showed that all catfish undergo long-term fasting periods (> 20 days). Of note, the feeding/fasting pattern coincides with the wet/dry seasons in Thailand, which also corresponds to the abundance of the catfish food resource (Cladophora spp.). We found that P. gigas exhibit a seasonal feeding rhythm that is synchronized by food availability. Furthermore, we found that the seasonal feeding rhythm was gradually dampened over time, suggesting that the observed seasonal feeding rhythm with long-term fasting of the catfish is likely controlled by an endogenous clock system. To our knowledge, this is the first case of quantification of the seasonal feeding rhythm with fasting periods in teleost fish.

Intensive granulocyte and monocyte adsorption versus intravenous prednisolone in patients with severe ulcerative colitis: an unblinded randomised multi-centre controlled study

BACKGROUND AND AIM

Several uncontrolled studies have reported on the efficacy of adsorptive depletion of peripheral blood granulocytes and monocytes/macrophages (GM) in patients with moderate or severe ulcerative colitis. This study was to compare the efficacy and safety of intensive GMA with intensive intravenous prednisolone in patients with severe ulcerative colitis.

METHODS

Seventy patients with clinical activity index 10-23 were randomly assigned to intensive GMA with the Adacolumn, at 2 sessions/week in the first 3 weeks and then 1 session/week for up to 11 sessions (n = 35) or intravenous prednisolone, 40-60 mg/day for 5-10 days (n = 35). No patient received immunomodulators within 8 weeks prior to entry. Clinical response based on intention to treat was assessed at weeks 2, 6 and 12.

RESULTS

Four patients in the prednisolone group and two patients in the GMA group discontinued in week 1. At weeks 2, 6 and 12, the remission (clinical activity index < or = 4) rates (%) in the GMA group were 17.1, 54.4, 74.3, respectively. The corresponding values in the prednisolone group were 25.7, 51.4 and 48.6. Further, at week 12, 27 patients (77%) in the GMA group and 5 patients (14%) in the prednisolone group were steroid free (P = 0.0076). In the GMA group, flushing and light-headedness were observed in 5 patients versus typical steroid side effects in 29 patients of the prednisolone group.

CONCLUSIONS

In this clinical response to GMA was comparable or better than prednisolone. Further, the response to GMA was slower than to intravenous prednisolone, but was more sustainable than the latter.

Effects of melatonin and superoxide dismutase on free radical formation in the postischemic reperfused heart

PURPOSE

Melatonin has been reported to protect against oxygen free radicals. We investigated whether melatonin or superoxide dismutase (SOD) would decrease hydroxyl radical concentration in the postischemic reperfused heart.

METHODS

An isolated rat heart-lung preparation was used. Eighty-one male Wistar rats were allocated into control (no drug), S1 (SOD 400 U.ml(-1)), S2 (SOD 2000 U.ml(-1)), M1 (melatonin 0.1 microg.ml(-1)), M2 (melatonin 1.0 microg.ml(-1)), M3 (melatonin 10 microg.ml(-1)), SM (SOD 400 U.ml(-1) and melatonin 1.0 microg.ml(-1)) groups. The heart was perfused initially at the cardiac output of 30 ml.min(-1) and the mean arterial pressure of 70 mmHg. Drugs were administered into the reservoir 7 min after the start of perfusion. Ten minutes after the start of perfusion, the heart was rendered globally ischemic for 10 min by reducing the preload and afterload to zero and then reperfused for 10 min. At the end of reperfusion, the heart was freeze-dried for 6 days. The perfusate blood was collected just before and after ischemia and at the end of reperfusion. The formation of hydroxyl radicals in perfusate blood and heart was measured with high-performance liquid chromatography using salicylic acid. Hydroxyl radicals react with salicylic acid, yielding 2,3-, 2,4-, 2,5-, and 3,4-dihydroxybenzoic acid (DHBA).

RESULTS

Before and after ischemia, there were no significant differences among the groups in cardiac output, systolic pressure, heart rate, and right atrial pressure. The concentrations of DHBAs in the perfusate blood and heart after ischemia and reperfusion in all groups were significantly higher than those before ischemia. DHBAs in the heart of all drug-administered groups were significantly lower than those in the control group. In the perfusate blood, DHBAs in the S2 group were significantly lower than those in the control group.

CONCLUSIONS

SOD and melatonin decrease hydroxyl radical concentration in the postischemic reperfused heart.

[The influence of N-nitro-L-arginine methyl ester (L-NAME) on hydroxyl free radical formation in the post-ischemic reperfused heart of anesthetized rats]

N-nitro-L-arginine methyl ester (L-NAME) has been reported to have protective action against hydroxyl free radicals. We have investigated whether L-NAME influences free radical formation in the post-ischemic reperfused heart of anesthetized rats. An isolated rat heart-lung preparation was used. Forty male Wistar rats were allocated into D (D-NAME 100 microMol.l-1), L (L-NAME 100 microMol.l-1), LH (L-NAME 100 microMol.l-1 and 1MAC halothane), LI (L-NAME 100 microMol.l-1 and 1MAC isoflurane), and LS (L-NAME 100 microMol.l-1 and 1MAC sevoflurane) groups. The heart was perfused initially at the cardiac output of 30 ml.min-1 and the atrial pressure of 70 mmHg. Drugs were administered into the reservor 7 min after the start of perfusion. Ten minutes after the start of perfusion, the heart was rendered globally ischemic for 10 min by reducing the preload and afterload to zero and then reperfused for 10 min. At the end of reperfusion, the heart was freeze-dried for 4 days. The perfusate blood was collected just before and after ischemia and at the end of reperfusion. The formation of hydroxyl radicals in the perfusate blood and heart was measured with high-performance liquid chromatography using salicylic acid. Hydroxyl radicals react with salicylic acid, yielding dihydroxybenzoic acid (DHBA). Before and after ischemia, there were no significant differences among the groups in cardiac output, systolic pressure, heart rate, and right atrial pressure. DHBAs in the heart of L, LH, LI, and LS groups were significantly lower than those of D group. However, there were no differences in the DHBA levels among 4 groups. The concentrations of DHBA in the perfusate blood after ischemia and reperfusion were significantly higher than those before ischemia in all groups. DHBAs in the perfusate blood after ischemia and reperfusion of L, LH, LI, and LS groups were significantly lower than those of D group. However, there were no differences in the DHBA levels among 4 groups administered L-NAME. This study indicates that L-NAME reduces hydroxyl free radical formation in the post-ischemic reperfused heart in anesthetized rats and volatile anesthetics do not influence the depressant effect of hydroxyl free radical formation by L-NAME.

Haplotype-phenotype correlation in Fukuyama congenital muscular dystrophy

In typical Fukuyama congenital muscular dystrophy (FCMD), peak motor function is usually only unassisted sitting or sliding on the buttocks, though a few patients are able to walk at some point. However, a few patients have a severe phenotype and never acquire head control. In addition, it is clinically difficult to differentiate this severe FCMD from Walker-Warburg syndrome (WWS) or from muscle-eye-brain disease (MEBD). In order to establish a genotype-phenotype correlation, we performed haplotype analysis using microsatellite markers closest to the FCMD gene (FCMD) in 56 Japanese FCMD families, including 35 families whose children were diagnosed as FCMD with the typical phenotype, 12 families with a mild phenotype, and 9 families with a severe phenotype. Of the 12 propositi with the mild phenotype, 8 could walk and the other 4 could stand with support; 10 cases were homozygous for the ancestral founder (A-F) haplotype whereas the other 2 were heterozygous for the haplotype. In the 9 severe cases, who had never acquired head control or the ability to sit without support, 3 had progressive hydrocephalus, 2 required a shunt operation, and 7 had ophthalmological abnormalities. Haplotype analysis showed that 8 of the 9 cases of the severe phenotype are heterozygous for the A-F haplotype, and the other one homozygous for the haplotype. We confirmed that at least one chromosome in each of the 56 FCMD patients has the A-F haplotype. The rate of heterozygosity for the A-F haplotypes was significantly higher in severe cases than in typical or mild cases (P < 0.005). Severe FCMD patients appeared to be compound heterozygotes for the founder mutation and another mutation. Thus, the present study yielded molecular genetic evidence of a broad clinical spectrum in FCMD.

[Effects of hypertonic lactated Ringer's solution on hepatic ATP and L/P ratio in rats subjected to acute hemorrhage]

This study aimed to clarify the difference in the effects of hypertonic lactated Ringer's solution (HLS) on hepatic ATP level and L/P ratio during acute hemorrhage in rats. The hepatic ATP level in HLS 230 group was lower, and L/P ratio in HLS 300 group was higher than those in the control group. There was no significant difference in glycogen among 4 groups. However, pH and the base excess in HLS 230 and HLS 300 group were significantly higher than those in the C group. Heart rate in HLS 300 group was significantly lower than that in the C group. These results suggest that HLS may not be useful with regard to the hepatic energy metabolism, although it improves the metabolic acidosis during acute hemorrhage.

Effects of sevoflurane and isoflurane on free radical formation in the post-ischaemic reperfused heart

Sevoflurane has been reported to generate oxygen free radicals. We have investigated whether sevoflurane or isoflurane enhances oxygen free radical formation in the post-ischaemic reperfused heart. An isolated rat heart-lung preparation was used. Thirty male Wistar rats were allocated to four groups: control, no drug, 2.5% sevoflurane and 1.4% isoflurane. The heart was perfused initially at a cardiac output of 30 mL min-1 and a mean arterial pressure of 70 mmHg. Ten minutes after the start of perfusion, the heart was rendered globally ischaemic for 10 min by reducing the preload and afterload to zero. Then, the heart was reperfused for 10 min. At the end of reperfusion, the heart was freeze dried for 6 days. The perfusate blood was collected just before and just after ischaemia and at the end of reperfusion. The formation of hydroxyl radicals in perfusate blood and heart was measured with high-performance liquid chromatography using salicylic acid. Hydroxyl radicals react with salicylic acid, yielding 2,3-, 2,4-, 2,5- and 3,4-dihydroxybenzoic acid (DHBA). Before and after ischaemia, there were no significant differences in cardiac output, systolic pressure, heart rate and right arterial pressure among the groups. The concentrations of 2,3-, 2,4-, 2,5- and 3,4-DHBA in the perfusate blood after ischaemia and reperfusion were significantly higher than those before ischaemia in all groups. However, there were no differences in the DHBA levels among groups. This study indicates that sevoflurane and isoflurane do not enhance hydroxyl radical formation in the post-ischaemic reperfused heart.

Prenatal diagnosis of Fukuyama type congenital muscular dystrophy in eight Japanese families by haplotype analysis using new markers closest to the gene

We conducted prenatal diagnosis by haplotype analysis, using newly developed microsatellite markers, in eight Fukuyama type congenital muscular dystrophy (FCMD) families. In addition to six new families, two previously reported families were reexamined by haplotype analysis including detection of an ancestral founder haplotype (138-183-301) for 3 microsatellite markers closest to the FCMD gene, designated D9S2105-D9S2107-D9S172, the distances of which from the FCMD gene are presumed to be approximately 140, approximately 20, and approximately 280 kb, respectively. Five fetuses from five families were diagnosed as nonaffected, and were subsequently confirmed to be healthy. Three fetuses of the other three families were diagnosed as having a high probability of being affected by FCMD. In the prenatal diagnosis conducted for these eight families, the ancestral founder allele was observed in 13 of 16 (81%) FCMD-bearing chromosomes. Detection of the ancestral haplotype facilitated achieving accurate prenatal diagnosis of FCMD. The brains of all three fetuses prenatally diagnosed as FCMD-affected showed the initial stage of cortical dysplasia, strong evidence of FCMD.

[Effects of lactated Ringer solution and acetated Ringer solution on hepatic ATP and L/P ratio in rats subjected to acute hemorrhage]

This study aimed to clarify the difference in the effects of lactated Ringer solution (LR) and acetated Ringer solution (AR) on hepatic ATP level and L/P ratio during acute hemorrhage in rats. There were no significant differences in the hepatic ATP levels and L/P ratios among 3 groups. Glycogen in LR group was higher than that in the control group. However pH and the base excess in LR and AR group were significantly higher than those in the C group. These results suggest that LR as well as AR may improve the metabolic acidosis, and LR may be more useful than AR with regard to glucose supply during acute hemorrhage.

Localization of laminin subunits in the central nervous system in Fukuyama congenital muscular dystrophy: an immunohistochemical investigation

We have undertaken an immunohistochemical study of laminin subunits in the central nervous system (CNS) of fetuses and patients with Fukuyama congenital muscular dystrophy (FCMD) and of controls including five fetuses. Immunoreaction product deposits with antibodies to laminin alpha 1, alpha 2, beta 1 and gamma 1, and beta-dystroglycan were detected on the surface and vessels of the CNS of controls. No staining with anti-alpha-sarcoglycan antibody was detected in the CNS. Neurons and glia did not react with any of the antibodies used. In utero expression of laminin subunits and beta-dystroglycan seemed to be lower in the cerebrum than in the spinal cord. Moreover, immunostaining for laminin alpha 2 and beta 1 tended to be weak on the fetal spinal cord surface. Expression of laminin subunits and dystrophin-associated proteins in the CNS may be modulated during development, as in the skeletal muscle. The distribution of immunoreaction product deposits was basically the same in FCMD and controls, although laminin alpha 2 and beta-dystroglycan expression appeared to be decreased in the CNS of the FCMD cases. Defects of the pial-glial barrier of the fetal brain surface have been considered the main cause of micropolygyria in FCMD, and these observations suggest that the co-localization and secondary loss of these proteins in association with the unknown product(s) of the FCMD gene might be involved in the CNS lesions of this disorder.

[Effects of steroids on hepatic ATP and L/P ratio in rats subjected to acute hemorrhage]

Both steroids and hemorrhage may affect the hepatic energy metabolism. The effects of steroids (5 mg.kg-1 of methylpredonisolone, 50 mg.kg-1 of methylpredonisolone, 25 mg.kg-1 of hydrocortisone and 250 mg.kg-1 of hydrocortisone) on hepatic ATP level and L/P ratio were evaluated in rats under acute hemorrhage. There were no significant differences in the hepatic ATP levels and L/P ratio among 5 groups. However, the base excess in 3 steroid groups (50 mg.kg-1 of methylpredonisolone, 25 mg.kg-1 of hydrocortisone and 250 mg.kg-1 of hydrocortisone) was significantly higher than that in the control group. This result suggests that steroids may improve the metabolic acidosis during acute hemorrhage.

Somatic mosaicism for a DMD gene deletion

Mosaicism is a mixed state, with two cell populations of different genetic origins caused by a cell mutation occurring after fertilization. In the present case, DNA analysis of lymphocytes led to a DMD diagnosis before death. Postmortem immunocytochemical and DNA analysis showed somatic mosaicism. At age 18 years, blood lymphocyte DNA analysis showed a DMD gene deletion, upstream from exon 7 to the 5' end containing both muscle and brain promoters. As the patient's mother and elder sister had no deletions, he was considered to have a new mutation. Immunocytochemical studies of postmortem tissues showed that dystrophin was absent from the tongue, deltoid, intercostal, psoas and rectus femoris muscles, but there was a mix of dystrophin-positive and negative fibers in the rectus abdominis, cardiac, temporalis and sternocleidomastoid muscles. All diaphragm cells were dystrophin positive. Polymerase chain reaction (PCR) amplification from all tissues except the temporalis and sternocleidomastoid muscles, diaphragm and kidney, in which no deletion was found, showed the deletion from at least exon 6 to the 5' end containing both muscle and brain promoters. In this case, a genomic deletion of the DMD gene contributed to the formation of tissues derived from both ectoderm and endoderm, and cells of mesodermal origin showed genotypic and phenotypic heterogeneity. Our results indicate a mutation of the present case may have occurred just before the period of germ layer formation.

[Anesthetic management of laparoscopic ovarian cystectomy in a 2-year-old child]

We have experienced the anesthetic management of laparoscopic ovarian cystectomy in a 2-year-old child. The patient was anesthetized with isoflurane and manually ventilated to keep PaCO2 at 30 mmHg prior to the carbon dioxide insufflation of the peritoneal cavity. Two minutes after the abdomen was distended, end-tidal CO2 began to increase and after 10 minutes PaCO2 was 50 mmHg. We had to increase tidal volume and respiratory rate, although airway pressure was 30 cmH2O. We should be careful because children who undergo pneumoperitoneum become hypercapnic easily during general anesthesia.

[Molecular genetics of Duchenne/Becker muscular dystrophy]

The X-linked gene responsible for Duchenne muscular dystrophy (DMD)/Becker muscular dystrophy (BMD) encodes dystrophin, a high-molecular-weight cytoskeletal protein. The identification of the dystrophin gene through positional cloning, and the subsequent description of its protein product have opened several new fields of research and genetic diagnosis. Studies in our laboratory revealed that 26 out of 47 (55%) cases of DMD and nine out of 12 (75%) cases of BMD exhibited genomic deletion. The DMD phenotype is associated with mutations that shift the reading frame of the message, whereas the BMD phenotype is associated with mutations that maintain the reading frame. Immunofluorescence microscopy has established dystrophin's distribution on the plasma membrane of muscles. DMD patients demonstrate a lack of dystrophin on their muscle cell membrane, whereas BMD patients produce a limited amount of protein or abnormally sized protein. Extensive studies on dystrophin and the gene may lead to an understanding of the cause for this and may allow development of a rational treatment for DMD to be developed.

[Clinical significance of dystrophin test for patients with various neuromuscular diseases--immunofluorescence and immunoblot analyses of dystrophin abnormalities]

The dystrophin test was performed on skeletal muscle specimens from 81 cases with various neuromuscular diseases by using two new monoclonal antibodies. The results were compared with those obtained by using four polyclonal antibodies. These monoclonal and polyclonal antibodies were raised against various portions of the dystrophin molecule. On immunohistochemical analysis, the two new monoclonal antibodies showed the same staining pattern as the four polyclonal antibodies. Non-specific immunostaining of the cytoplasm, often seen with polyclonal antibodies, was not observed with monoclonal antibodies. With the application of monoclonal antibodies, the connective tissue sometimes showed non-specific immunostaining which originated from the second fluorescent antibody. On immunoblot analysis, one of the two monoclonal antibodies, antibody 4-4 C 5, showed weak immunoreactivity, and the 400 kDa dystrophin band was not detected. Three cases out of 15 with Duchenne muscular dystrophy (DMD), and one case out of 3 with limb-girdle type muscular dystrophy which had previously been diagnosed on the basis of clinical data, were found to have non-dystrophin-related muscular dystrophy, and Becker muscular dystrophy (BMD), respectively. Three and two of five cases were diagnosed as DMD and BMD, respectively, though clinical diagnosis had not been possible because they were too young. Clinical diagnosis of congenital muscular dystrophy was confirmed in 9 patients by the dystrophin test. Only one of three certain DMD carriers had a so-called mosaic staining pattern. We conclude that all six antibodies are useful tools for the diagnosis of neuromuscular diseases, because of their high specificity for dystrophin.

Molecular genetic and immunological analysis of dystrophin of a young patient with X-linked muscular dystrophy

We examined the nucleotide sequence of deleted part of dystrophin mRNA and its translational product with immunoblot and immunohistochemical methods in a 6-year-old boy with a deleted DMD/BMD gene. On Southern blot analysis of his genomic DNA, we found a deletion of exons 10 to 37 in the DMD/BMD gene, which was expected to preserve the translational open reading frame (ORF). Dystrophin mRNA from his biopsy sample was amplified by polymerase chain reaction (PCR) and sequenced. The mRNA lacked the sequence corresponding to the gene from exons 10-37, and the translational ORF was preserved. The transcript was expected to code a 260 kDa protein. Dystrophin expressed in this patient was investigated with immunological methods. A 260 kDa protein was detected by immunoblot analysis with antidystrophin antiserum against nondeleted regions. These observations confirmed the preservation of the reading frame and the 260 kDa protein was produced as a mutant dystrophin. All these are compatible with the diagnosis of BMD. However, the immunohistochemical pattern of his muscle cells was peculiar. With deleted-region-directed antiserum, the membrane was not stained at all as in DMD patients. In contrast, with nondeleted-region-directed antiserum, all the muscle cell membrane was stained continuously as in non-DMD/BMD individuals. These are quite different from the staining pattern in most BMD patients where muscles are stained patchily or discontinuously.

Human CYP1A1 gene: cosegregation of the enzyme inducibility phenotype and an RFLP

The human CYP1A1 (cytochrome P1450) gene encodes an enzyme involved in the activation of procarcinogens, such as benzo[a]pyrene, to the ultimate reactive intermediate. Approximately 10% of the human population exhibit high CYP1A1 inducibility, and Kouri et al. reported that the high-inducibility phenotype might be at greater risk than low-inducibility individuals for cigarette smoke-induced bronchogenic carcinoma. In one 3-generation family of 15 individuals, we show here that the high-CYP1A1-inducibility phenotype segregates concordantly with an infrequent polymorphic site located 450 bases downstream from the CYP1A1 gene. Our findings are consistent with the study of Kawajiri et al., who demonstrated an association between this polymorphism and an increased incidence of squamous-cell lung cancer. Our data suggest that the CYP1A1 structural gene, or a region near this gene, might be correlated with the inducibility phenotype.

Difference in the expression pattern of dystrophin on the surface membrane between the skeletal and cardiac muscles of mdx carrier mice

We examined the expression of dystrophin by immunohistochemical and immunoblot analyses in the skeletal and cardiac muscles of Xmdx/X+ heterozygous mice, which were obtained by mating male mdx mice (Xmdx/Y) with female wild type mice (X+/X+). Dystrophin was expressed on the surface membrane in both muscles, but the mode of expression was different between the two muscles. In cardiac muscle, dystrophin positive and negative cells were present in roughly equal numbers intermingled in a mosaic pattern; this was considered to reflect the random inactivation of X-chromosomes in early development. In skeletal muscle, most of the surface membrane was dystrophin positive. There were little signs of fiber necrosis or regeneration, and serum creatine kinase levels were normal. We are at present of opinion that the predominance of dystrophin-positive area in skeletal muscle is due to intracellular diffusion of dystrophin.

Human CYP1A2: sequence, gene structure, comparison with the mouse and rat orthologous gene, and differences in liver 1A2 mRNA expression

We have sequenced the human CYP1A2 (cytochrome P(3)450) gene, 1,906 basepairs (bp) of the 5' flanking region, and 113 bp of the 3' flanking region. The gene spans almost 7.8 kilobases, comprising seven exons and six introns. The transcriptional start site was determined by both primer extension and S1 mapping. Including the first noncoding exon of 55 bp, the entire mRNA is 3,121 bp in length, and the open reading frame, starting with nucleotide 10 of exon 2, encodes 515 amino acids (mol wt = 58,294). Between the human CYP1A2 and CYP1A1 (cytochrome P(1)450) genes, exons 2, 4, 6, and especially 5 are strikingly conserved in both nucleotide similarity and total number of bases. Alignment of the upstream sequences and exon 1 of human CYP1A2 with that of mouse or rat CYP1A2 revealed two possibly significant regions of similarity: 1) 68% in the approximately 150 bases immediately 5' from the mRNA cap site and 2) 80% identify between the human -841 to -758 segment and the mouse -1,529 to -1,439 segment. The canonical 5-bp box (CACGC), found upstream of all mammalian CYP1A1 genes to date and believed to interact with the inducer.aromatic hydrocarbon receptor complex, was not found on either strand in the 1,906 bp of the 5' flanking region of human CYP1A2. In contrast, alignment of the upstream sequences, exon 1, and intron 1 of human CYP1A1 with that of mouse or rat CYP1A1 revealed large, highly conserved regions. Conserved regions were found in intron 1 of the human, mouse, and rat CYP1A2 gene. These data suggest that the regulatory elements controlling the CYP1A2 gene might differ in location from those controlling the CYP1A1 gene. Among 12 human liver samples, striking differences (greater than 15-fold) in the 3.3-kilobase 1A2 mRNA levels were seen. This result may reflect significant genetic differences in constitutive and/or inducible CYP1A2 gene expression that could play an important role in individual risk of environmental toxicity or cancer.