Evaluation of muscle damage after a rugby match with special reference to tackle plays

OBJECTIVE

To investigate blood indices of muscle damage after a competitive rugby match.

METHODS

Fifteen elite amateur rugby players volunteered to participate (mean (SE) age 26.6 (0.7) years, height 179.8 (1.0) cm, weight 87.4 (2.2) kg, and VO2MAX 58.5 (1.2) ml/kg/min). The study was conducted after two competitive matches during the 1999-2000 season. Plasma concentrations of lactate, potassium (K+), sodium (Na+), and myoglobin, and the activity of creatine kinase were measured before and after the matches. In addition, the number of tackles by and on each subject and the average duration of the work and rest periods were analysed using video recordings of the matches.

RESULTS

Myoglobin concentration and creatine kinase activity showed appreciable transient increases after the match. Peak values for myoglobin concentration (980 (166) microg/l) and creatine kinase activity (1081 (159) U/l) were observed 45 minutes and 24 hours after the match respectively. Positive and significant correlations were observed between the number of tackles and both peak myoglobin concentration (r=0.85, p<0.01; n=14) and peak creatine kinase activity (r=0.92, p<0.01; n=14). Plasma lactate and K+ concentrations also showed appreciable increases after the match, whereas plasma Na+ concentration showed a gradual decrease. The mean duration of the work and rest periods were 21.5 (2.2) and 24.3 (3.1) seconds respectively.

CONCLUSIONS

The rugby matches resulted in serious structural damage to the muscles, the extent of which was highly dependent on the number of tackles.

Applications of vascular occlusion diminish disuse atrophy of knee extensor muscles

PURPOSE

We have previously shown that the combination of low-intensity resistive exercise and moderate vascular occlusion induces in humans a marked increase in growth hormone secretion and muscular hypertrophy. The present study investigated the effects of vascular occlusion on the size of thigh muscles in patients who underwent an operation for the reconstruction of the anterior cruciate ligament to see whether it attenuates the disuse muscular atrophy without any exercise combined.

METHODS

Two sessions of occlusive stimulus, each consisting of five repetitions of vascular occlusion (mean maximal pressure, 238 mm Hg) for 5 min and the release of occlusion for 3 min, were applied daily to the proximal end of the thigh from 3rd to 14th days after the operation. Changes in the cross-sectional area (CSA) of thigh muscles were analyzed with magnetic resonance images taken on the 3rd and 14th day after the operation.

RESULTS

Without occlusive stimulus (control), the CSAs of knee extensors and flexors decreased by 20.7 +/- 2.2% and 11.3 +/- 2.6% (mean +/- SEM, N = 8), whereas with the occlusive stimulus, they decreased by 9.4 +/- 1.6% and 9.2 +/- 2.6% (N = 8), respectively. The relative decrease in CSA of knee extensors was significantly (P < 0.05) larger in the control group than in the experimental group.

CONCLUSION

The results indicate that the occlusive stimulus effectively diminishes the postoperation disuse atrophy of knee extensors.

Effects of resistance exercise combined with moderate vascular occlusion on muscular function in humans

Acute and long-term effects of resistance exercise combined with vascular occlusion on muscular function were investigated. Changes in integrated electromyogram with respect to time (iEMG), vascular resistive index, and plasma lactate concentration were measured in five men either during or after elbow flexion exercises with the proximal end of the arm occluded at 0-100 mmHg. The mean iEMG, postexercise hyperemia, and plasma lactate concentration were all elevated with the increase in occlusion pressure at a low-intensity exercise, whereas they were unchanged with the increase in occlusion pressure at high-intensity exercise. To investigate the long-term effects of low-intensity exercise with occlusion, older women (n = 24) were subjected to a 16-wk exercise training for elbow flexor muscles, in which low-intensity [ approximately 50-30% one repetition maximum (1 RM)] exercise with occlusion at approximately 110 mmHg (LIO), low-intensity exercise without occlusion (LI), and high- to medium-intensity ( approximately 80-50% 1 RM) exercise without occlusion (HI) were performed. Percent increases in both cross-sectional area and isokinetic strength of elbow flexor muscles after LIO were larger than those after LI (P < 0.05) and similar to those after HI. The results suggest that resistance exercise at an intensity even lower than 50% 1 RM is effective in inducing muscular hypertrophy and concomitant increase in strength when combined with vascular occlusion.

Rapid increase in plasma growth hormone after low-intensity resistance exercise with vascular occlusion

Hormonal and inflammatory responses to low-intensity resistance exercise with vascular occlusion were studied. Subjects (n = 6) performed bilateral leg extension exercise in the seated position, with the proximal end of their thigh compressed at 214 +/- 7.7 (SE) mmHg throughout the session of exercise by means of a pressure tourniquet. Mean intensity and quantity of the exercise were 20% of 1 repetition maximum and 14 repetitions x 5 sets, respectively. In each set, the subjects repeated the movement until exhaustion. Plasma concentrations of growth hormone (GH), norepinephrine (NE), lacate (La), lipid peroxide (LP), interleukin-6 (IL-6), and activity of creatine phosphokinase (CPK) were measured before and after the exercise was finished and the tourniquet was released. Concentrations of GH, NE, and La consistently showed marked, transient increases after the exercise with occlusion, whereas they did not change a great deal after the exercise without occlusion (control) done at the same intensity and quantity. Notably, concentration of GH reached a level approximately 290 times as high as that of the resting level 15 min after the exercise. IL-6 concentration showed a much more gradual increase and was maintained at a slightly higher level than in the control even 24 h after exercise. Concentrations of LP and CPK showed no significant change. The results suggest that extremely light resistance exercise combined with occlusion greatly stimulates the secretion of GH through regional accumulation of metabolites without considerable tissue damage.

Development of an enzyme-labeled oligonucleotide probe for detecting the Escherichia coli attaching and effacing A gene

Enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic Escherichia coli (EHEC) can produce attaching and effacing (AE) lesions on intestinal epithelium in vitro and in vivo. A gene necessary to cause the AE lesion has been identified and designated Escherichia coli attaching and effacing A (eaeA) gene. In this study, an alkaline phosphatase (ALP)-conjugated oligonucleotide probe for the eaeA gene was developed and used to detect the eaeA gene among 163 strains of classical EPEC and 25 strains of EHEC O157. The prevalence rates of eaeA gene in the strains of classical EPEC and EHEC O157 were 51.5 and 100%, respectively. The eaeA-positive rate (60.0%) in strains of class I EPEC serogroups (O26, O55, O86, O111, O119, O125, O126, O127, O128ab, and O142) was significantly higher than that (22.9%) in strains of the class II EPEC serogroups (O18, O44, O114) (P<0.01). A total of 109 eaeA-positive classical EPEC and EHEC O157 were positive for fluorescent actin staining (FAS) assay, whereas 79 eaeA-negative classical EPEC were negative. Both the sensitivity and specificity of the eaeA probe versus the FAS assay positivity were 100%. Thus, use of the ALP-conjugated oligonucleotide probe for the eaeA gene would be specific and reliable in identifying the adherence capability of EPEC and EHEC.

Serum levels of tumor necrosis factor-alpha are increased in obese patients with noninsulin-dependent diabetes mellitus

To clarify the significance of the serum levels of tumor necrosis factor-alpha (TNF-alpha) in the mechanism of insulin resistance, we studied 12 obese patients with noninsulin-dependent diabetes mellitus (NIDDM). We evaluated the relationship of TNF-alpha levels with the visceral, subcutaneous, and total fat areas measured by computed tomography (CT), and with insulin resistance evaluated by the glucose infusion rate (GIR) observed during an euglycemic hyperinsulinemic clamp study. Controls consisted of 12 normal subjects and 12 nonobese patients with NIDDM. TNF-alpha levels were measured using a high sensitivity enzyme-linked immunosorbent assay. Following admission, all patients with NIDDM participated in a 4-week program of diet and exercise. After this treatment, we evaluated the relationship of the serum levels of TNF-alpha with the area of body fat, the GIR, and the resultant change in the TNF-alpha level. Serum levels of TNF-alpha in the obese patients with NIDDM significantly exceeded those observed in normal subjects (P < 0.01) or in the nonobese patients with NIDDM (P < 0.01). Serum levels of TNF-alpha in obese NIDDM patients showed a significant positive correlation with the area of visceral fat before (r = 0.662, P < 0.03) and after (r = 0.508, P < 0.05) the treatment; similar correlation was observed in all patients with NIDDM before (r = 0.537, P < 0.02) and after (r = 0.430, P < 0.05) the treatment. Serum levels of TNF-alpha in obese NIDDM patients showed a significant negative correlation with GIR after the treatment (r = -0.595, P < 0.05). Serum levels of TNF-alpha were significantly reduced in the obese patients with NIDDM after the treatment (P < 0.01), while those in the nonobese NIDDM patients were unchanged. These results suggest that serum TNF-alpha levels may play an important role in mechanism of insulin resistance associated with obesity.

Evaluation of enzyme-labeled oligonucleotide probes to identify enterohaemorrhagic Escherichia coli

Alkaline phosphatase-conjugated oligonucleotide probes were developed to detect the gene coding for Vero toxin 1 (VT1) and Vero toxin 2 (VT2). Using these probes, 3 hr was enough to detect VT genes when suspicious colonies of enterohaemorrhagic Escherichia coli (EHEC) were obtained on an agar plate. The results of a hybridization test with 144 isolates of EHEC O157 and one isolate of Shigella dysenteriae Type 1 agreed exactly with the immunological detection, reversed passive latex agglutination (RPLA) test, of VTs in their culture supernatants. The sensitivity levels of these probes for the detection of VT genes were 100%. The specificity of these probes were also tested with a total of 1,002 strains of Escherichia coli other than EHEC and 8 strains of Shigella sp. other than Shigella dysenteriae Type 1; the results showed 100% specificity.

Stretch-induced enhancement of mechanical power output in human multijoint exercise with countermovement

The relation between the eccentric force developed during a countermovement and the mechanical power output was studied in squatting exercises under nominally isotonic load (50% of 1-repetition maximum). The subjects (n = 5) performed squatting exercises with a countermovement at varied deceleration rates before lifting the load. The ground reaction force and video images were recorded to obtain the power output of the body. Net muscle moments acting at hip, knee, and ankle joints were calculated from video recordings by using inverse dynamics. When an intense deceleration was taken at the end of downward movement, large eccentric force was developed, and the mechanical power subsequently produced during the lifting movement was consistently larger than that produced without the countermovement. Both maximal and mean power outputs during concentric actions increased initially with the eccentric force, whereas they began to decline when the eccentric force exceeded approximately 1.4 times the sum of load and body weight. Video-image analysis showed that this characteristic relation was predominantly determined by the torque around the knee joint. Electromyographic analyses showed no consistent increase in time-averaged integrated electromyograph from vastus lateralis with the power output, suggesting that the enhancement of power output is primarily caused by the prestretch-induced improvement of an intrinsic force-generating capability of the agonist muscle.

Stretch-induced enhancement of mechanical work production in frog single fibers and human muscle

The relations between the velocity of prestretch and the mechanical energy liberated during the subsequent isovelocity release were studied in contractions of frog single fibers and human muscles. During isometric contractions of frog single fibers, a ramp stretch of varied velocity (amplitude, 0.02 fiber length; velocity, 0.08-1.0 fiber length/s) followed by a release (amplitude, 0.02 fiber length; velocity, 1.0 fiber length/s) was given, and the amount of work liberated during the release was measured. For human muscles, elbow flexions were performed with a prestretch of varied velocity (range, 40 degrees; velocity, 30-180 degrees/s) followed by an isokinetic shortening (velocity, 90 degrees/s). In both frog single fibers and human muscles, the work production increased with both the velocity of stretch and the peak of force attained before the release up to a certain level; thereafter it declined with the further increases of these variables. In human muscles, the enhancement of work production was not associated with a significant increase in integrated electromyogram. This suggests that changes in intrinsic mechanical properties of muscle fibers play an important role in the stretch-induced enhancement of work production.

Use of an alkaline phosphatase-conjugated oligonucleotide probe for the gene encoding the bundle-forming pilus of enteropathogenic Escherichia coli

An alkaline phosphatase-conjugated 29-base oligonucleotide probe was developed to detect the gene encoding the bundle-forming pilus of enteropathogenic Escherichia coli. The sensitivity and specificity of the probe versus the results of localized adherence in the HEp-2 cell assay and fluorescent actin staining assay positivity were 95.7 and 100%, respectively.

[Detection of hepatitis B virus by using polymerase chain reaction and nonradioactive DNA probes. II. Identification of mutations in the core gene by PCR-direct sequencing and ASO probe method]

Mutants of hepatitis B virus (HBV) in the pre-core/core gene exist in patients chronically infected with HBV. The core gene of HBV DNA is preceded by the pre-core region which takes a role of synthesis and secretion of HBe antigen (HBeAg). Previous studies have suggested that products of the core gene could be immunological targets of cytotoxic T lymphocytes as well as those of variant pre-core genes and subsequently, that the clinical courses of HBV carriers might be influenced due to infected HBV variants. In this study, we therefore examined mutations in the core gene of HBV DNA on strains with or without a translational stop codon at the 28th codon of the pre-core region, using allele-specific oligonucleotide (ASO) probes and PCR-direct sequencing. The analysis of nucleotide sequences (codon 27-100) of HBV DNA in anti-HBe positive sera showed that there were two hypervariable segments of codon 31-49 and codon 87-97, where amino acid substitutions of L31I, S49T, S87G/N, K96N and I87F/1 frequently occurred regardless of the presence or absence of the mutation in the pre-core region. Meanwhile, less mutations were detected in the core gene of HBV DNA in HBeAg positive sera. Furthermore, we could identify the mutations at codon 87, 96 and 97 by using nonradioactive probes in a good coincidence with results by PCR-direct sequencing. The ASO probe method is useful for detection of mutations in the core gene in many specimens.

Detection of the gene for toxic shock syndrome toxin 1 in Staphylococcus aureus by enzyme-labelled oligonucleotide probes

A colony hybridisation method with enzyme-labelled oligonucleotide probes was developed to detect the gene for toxic shock syndrome toxin 1 (tst). For rapid identification, bacterial colonies were transferred from agar plates directly on to nylon membranes. These procedures took only 3 h. Results obtained by this test correlated well with those obtained by the reverse passive latex agglutination test. Thus, this method is convenient and reliable for the detection of tst in staphylococci, which could be useful for both research and clinical purposes. This method demonstrated that tst was more prevalent in methicillin-resistant Staphylococcus aureus (56%) than in methicillin-susceptible S. aureus (4%).

[Detection of hepatitis B virus by using polymerase chain reaction and nonradioactive DNA probes. I. Identification of mutations in the precore region by PCR-direct sequencing and ASO probe method]

Seroconversion from hepatitis B e antigen (HBeAg) to anti-HBe antibody (anti-HBe) frequently occurs in hosts chronically infected with hepatitis B virus (HBV). Further, this phenomenon is related to a point mutation from guanine to adenine at nucleotide 83 in the precore region of HBV, which, converts codon 28 for tryptophan (TGG:W) to a translational, stop codon (TAG:X). Therefore, we decided to examine HBV in sera from patients for mutations in the precore region by a simple allele-specific oligonucleotide (ASO) probe method. Direct sequencing was first performed on DNA fragments amplified by the polymerase chain reaction in order to establish whether there were mutations in the precore region. Subsequently, specific DNA probes were applied to detection of mutations in the precore region. Subsequently, specific DNA probes were applied to detection of mutations in the precore gene. Five unknown mutations (I10N, C12W, C14S, V17F and A19D), three known mutations (I9V, W28X and G29D) and for novel nucleotide insertions were identified in anti-HBe positive sera. By using seven nonradioactive probes, we could determine the mutations at codons 9, 28 and 29 in anti-HBe positive sera. The W28X mutation was found in anti-HBe positive but not in any of HBeAg positive sera. Meanwhile, wild-type strains of HBV were detectable in sera from patients who were positive to HBeAg or anti-HBe. This ASO probe assay could determine in a few days the mutations in the precore region of HBV, especially including the defect to prohibit the synthesis and secretion of HBeAg.

Use of a new oligonucleotide probe for detection of colonization factor antigen III gene in enterotoxigenic Escherichia coli

An alkaline phosphatase-labeled 30-mer oligonucleotide probe was designed to detect the gene for pilus colonization factor antigen III (CFA/III) of the human type of enterotoxigenic Escherichia coli (ETEC). The CFA/III probe was used to identify CFA/III-producing ETEC among 303 Escherichia coli obtained from subjects with traveler's diarrhea. Six isolates positive for the CFA/III gene were found. This result was confirmed immunologically by using a specific monoclonal antibody developed against CFA/III. These six isolates, isolated from travelers returning from India, Pakistan and China, were all positive for the gene of heat-labile enterotoxin and possessed an identical serotype (025:H-).

[Detection of Campylobacter species by using polymerase chain reaction and nonradioactive DNA probes. III. DNA probe for identification of C. laridis]

The development of a rapid and specific DNA probe assay for identification of Campylobacter species, including C. jejuni, C. coli, C. laridis, C. fetus, and C. hyointestinalis is important in determining the precise diagnosis of Campylobacter infections. Sequence data of our previous studies for a 240-base DNA fragment was used to select primers and probes conjugated to alkaline phosphatase, complementary to a portion of DNA between primers. However, a 21-base probe (CL (1)) tested here for detection of C. laridis was cross-reactive with PCR-amplified fragments of C. jejuni, C. coli and C. hyointestinalis, although it was not reactive with C. fetus and C. fetus subsp. fetus. To solve this problem, further modifications of the probe were therefore made to improve the specificity for those particular species. A second 21-base probe with a single base-substitution (CL (2)) and a third 20-base probe (CL(3)) were ineffective for identification of C. laridis, too. A fourth 20-base probe with a single base substitution (CL(4)) was a significant improvement over the results obtained by other three probes specifically to detect C. laridis, Thus, the alkaline phosphatase-labeled probe method developed so far is an interesting alternative without access to radioisotopes for clinical laboratories for identification of Campylobacter species, including C. jejuni/coli/hyointestinalis, C. laridis, and C. fetus/fetus subsp. fetus.

[Genetic diagnosis of phenylketonuria. IV. Mutations of phenylalanine hydroxylase gene in Caucasian and Gypsy populations in Czech and Slovakia Republics]

Direct sequencing was conducted on the regions of the exon 7 and 12 in the phenylalanine hydroxylase (PAH) gene amplified by the polymerase chain reaction, using solid-phase technology involving the biotin streptavidin system. A novel mutation and seven previously known mutations were identified in the PAH genes among 15 Caucasians and 10 Gypsies in the Czech and Slovakia republics, affected with classical phenylketonuria (PKU). Two of these substitutions (R243X and G272X) resulted in the generation of a premature stop codon, and a single base transition of G to A at codon 261 resulted in the substitution of Arg for Gln (R261Q). These three mutations together accounted for 16.7% of PKU alleles among 15 Caucasians. The R252W mutation was detected in these two groups: two Caucasians were compound heterozygous for the P281L or R408W mutations (6.7% of all mutant alleles). However, all 10 Gypsy PKU patients were homozygous for the R252W transition. The R408W mutation accounted for 43% of PKU alleles in 15 Caucasian PKU patients. A novel heterozygous C-to-G transversion at the third base of codon 263 in the exon 7, resulting in the substitution of Phe for Leu (F263L), was detected in a Caucasian PKU patient (3.3% of all mutant alleles). In this study, we revealed a novel PKU mutation of the F263L in Caucasian populations and a high-risk PKU mutation of the R252W in Gypsy populations.

[Detection of methicillin-resistant Staphylococcus aureus using PCR and non-radioactive DNA probes: IV. Mutational sequences in the region upstream of the mec A gene in clinical staphylococcal strains]

Expression of mec A is regulated by two regulatory genes (mecR1 and mecI); the intact regulatory genes exist in the N315 strain of methicillin-sensitive S. aureus, whereas the repressor gene (mecI) is deleted in the MR108 strain of methicillin-resistant S. aureus (MRSA). However, our previous findings that clinical strains of N315 type were methicillin-resistant suggest possible mutations within the operator region, by which the inhibitory effect of MecI is released to induce the constitutive expression of mec A. Therefore, we analyzed nucleotide sequences in the region upstream of the mec A gene and in the regulatory genes, by using PCR-direct sequencing and ASO probes. Analysis of selected clinical strains by ASO probes revealed that 74% of MRSA and 36% of MRSE (methicillin-resistant S. epidermidis) lacked the mecI gene whereas 26% of MRSA and 64% of MRSE possessed the intact regulatory genes. Furthermore, PCR-direct sequencing identified four different mutations in the operator nucleotide sequence and one mutation in Shine-Dalgarno sequence. Additionally, these mutations were shown to occur in the strains of N315 type with higher probability rather than in those of MR108 type. The data suggest that one or more of these mutational sequences at least may have some influence on the expression of methicillin-resistance in clinical staphylococcal strains.

[Genetic diagnosis of phenylketonuria. III. Mutations of phenylalanine hydroxylase gene in Orientals]

Phenylketonuria (PKU) is an autosomal recessive disorder caused by lesions in the phenylalanine hydroxylase (PAH) gene. The recent studies on PAH mutations show the genetic drift of PKU alleles among some Oriental populations. Therefore, we searched for PKU mutations among Japanese, Chinese and Taiwanese. Direct sequencing was conducted on DNA fragments amplified by the polymerase chain reaction, using solid-phase technology involving the biotin-streptavidin system. Two new mutations (R241C and G247V) and two of the known mutant alleles (Y204C and R243Q) were found in two Taiwanese and two Chinese PKU patients, and three known mutations (R111X, Y204C and R413P) were recognized in three Japanese; two new mutations were identified in exon 7 of the PAH gene at codon 241 and codon 247, where the single base changes from C to T and from G to T substituted cysteine for arginine and valine for glycine, respectively. Further all the PAH mutations detected are common in Oriental populations as they have been thus far unreported among Caucasians. From these data as well as the clinical phenotype of the patients, we suggest that the R241C and G247V substitutions may interfere with proper enzyme function, although we have not yet performed functional studies. More detailed studies would be needed to clarify the regional distribution of mutant chromosomes in Oriental populations and other unidentified mutations.

[Detection of methicillin-resistant Staphylococcus aureus using PCR and non-radioactive DNA probes: III. Mutations of the fem A gene in clinical strains of Staphylococcus aureus]

Methicillin resistance in S. aureus is primarily due to the presence of the mec A gene. However, in addition to mec, the phenotypic expression of methicillin resistance requires the presence of an additional gene(s), fem A which is chromosomally encoded. Previous studies suggest an increase in the biochemical function of fem A gene products due to base substitutions in the region upstream of the fem A gene and in its coding frame. The partial nucleotide sequences of fem A regions in reference and clinical strains of S.aureus were therefore analyzed by PCR-direct solid-phase sequencing and suitable DNA probes. Amplified target DNAs of 251, 330 and 271 bp were resolved on ethidium bromide-stained gels and hybridized with DNA probes conjugated to alkaline phosphatase. In ATCC 12600 strain, a palindromic sequence was conserved in the region upstream of fem A. However, it was destroyed by the occurrence of mutations in other reference, and clinical strains tested regardless of whether they are methicillin-susceptible or resistant. Furthermore, in the coding frame of fem A, two missense mutations were present in MSSA and MRSA without any regularity. These findings suggest that mutations in the fem A region may not be a single factor essential for regulation of methicillin resistance, although fem A probably functions cooperatively with mec A.

Development of enzyme-labeled oligonucleotide probe for detection of mecA gene in methicillin-resistant Staphylococcus aureus

A DNA hybridization method with an enzyme-labeled oligonucleotide probe (mecA-ELONP) was developed to detect the methicillin-resistant gene (mecA) in methicillin-resistant Staphylococcus aureus. For rapid identification, bacterial colonies were transferred from agar plates directly onto nylon membranes. Lysis of cells, denaturation of DNA, and hybridization were performed on the membranes. These procedures required only 3 h for completion. The results obtained by this test closely corresponded with those obtained by determining the MICs of oxacillin against S. aureus. The results of the mecA-ELONP also correlated well with those of a commercially available PCR test. Thus, mecA-ELONP proved to be a reliable and convenient method for the rapid identification of methicillin-resistant S. aureus, which could be useful in clinical microbiology laboratories.

Highly sensitive and specific amplification by primer digestion

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Gypsy phenylketonuria: a point mutation of the phenylalanine hydroxylase gene in Gypsy families from Slovakia

A direct mutational analysis of the phenylalanine hydroxylase gene (PAH) in Gypsy families with phenylketonuria (PKU) has not yet been presented. However, they obviously represent a group at high risk for this inherited disease. We analyzed the PAH loci of 65 Gypsies originating from Eastern Slovakia by a combination of PCR amplification, direct sequencing and ASO hybridization. These studies uncovered 10 "classical PKU" patients to be homozygous for a R252W (CGG-TGG) transition, and 29 heterozygous carriers of this mutation. Fifteen control Caucasoid PKU patients from the Czech and Slovak Republics were selected. In this group we detected R252W mutation in two subjects (6.67% of all mutant alleles). Both were compound heterozygous for two different mutations. Previous haplotype studies of Welsh Gypsies with PKU were uninformative in the determination of heterozygosity. ASO hybridization served us effectively for the consequent analyses in Gypsy PKU-related families and to identify the carriers among the unrelated subjects.

Demonstration and characterization of simultaneous production of a thermostable direct hemolysin (TDH/I) and a TDH-related hemolysin (TRHx) by a clinically isolated Vibrio parahaemolyticus strain, TH3766

Simultaneous production of a thermostable direct hemolysin (TDH)-like toxin (TDHx) and a TDH-related hemolysin (TRH)-like toxin (TRHx) by a clinical isolate (strain TH3766) of Kanagawa phenomenon-positive Vibrio parahaemolyticus was demonstrated and characterized. The two hemolysins were differentially purified by column chromatography on hydroxyapatite and immunoaffinity columns. The molecular weight of the two hemolysins were estimated to be 23,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (PAGE). The purified TDHx was indistinguishable from the previously reported TDH/I (from strain TH012) but was different from the authentic TDH of a Kanagawa phenomenon-positive strain (T4750) physicochemically. The mobility of TRHx in nondenaturing PAGE differed from all the known TDHs and TRHs. The genes (tdhX and trhX) coding for TDHx and TRHx were cloned and sequenced. Homologies of nucleotide sequences of the coding regions between tdhX and tdhA (a gene for the authentic TDH) and between trhX and trh (a gene for the authentic TRH) were 98.1 and 99.1%, respectively, and homology between tdhX and trhX was 68.1%. At the amino acid level, TdhX was completely identical to TDH/I, although two base differences were found in the nucleotide sequences between tdhX and tdh/I. Two amino acid differences were observed between TrhX and Trh. Thus, these findings suggest that the TH3766 strain produces two types of hemolysins simultaneously. This is the first evidence that a strain of V. parahaemolyticus produces two types of toxins of the TDH-TRH family at the same time.

Development of an enzyme-labeled oligonucleotide probe for the cholera toxin gene

An alkaline phosphatase-conjugated 30-mer oligonucleotide probe was developed to detect the cholera toxin gene (ctx) in Vibrio cholerae O1. For rapid identification, V. cholerae O1 was grown on selective agar (thiosulfate-citrate-bile salts agar) or in alkaline peptone water and organisms were transferred directly to nylon membranes. Lysis of cells, denaturation of DNA, neutralization, and hybridization were carried out on the membrane. These procedures required only 3 h for completion. The results of the hybridization test with 88 clinical and 20 environmental isolates agreed almost exactly with the results of the immunological tests (anti-cholera toxin antibody-sensitized latex agglutination tests). The specificity of the probe was also tested with strains of enterotoxigenic Escherichia coli, V. cholerae non-O1, and Vibrio mimicus.

[Detection of Campylobacter species by using polymerase chain reaction and nonradioactive DNA probes. II. PCR direct sequencing of the Campylobacter DNA]

We have developed a sensitive DNA hybridization assay for the detection and identification of Campylobacter species which are recognized as important pathogens of acute diarrheal disease in humans. This technique utilizes DNA probes complementary to nucleotide sequences present in 16S ribosomal RNA (rRNA) of C. jejuni, C. coli, C. laridis, C. fetus, C. fetus subsp. fetus, C. fetus subsp. venerealis and C. hyointestinalis, and polymerase chain reaction. The partial sequence of DNAs encoding the Campylobacter rRNA was first analyzed by direct solid phase sequencing in order to select suitable DNA probes. Amplified target DNA of 240 base pairs could be resolved on ethidium bromide-stained gels, and hybridized with DNA probes conjugated to alkaline phosphatase. In identification experiments, one of the 10 probes tested here gave a positive hybridization reaction with C. jejuni, C. coli and C. hyointestinalis but not with other Campylobacter species. The other was specifically reactive with C. fetus, C. fetus subsp. fetus and C. fetus subsp. venerealis. When applied to stool specimens, a good correlation was found between the results obtained by the present assay and by biochemical tests. These findings suggest that the nonradioactive probe assay can be used as the practical criterion for differentiating Campylobacter species.

[Genetic diagnosis of phenylketonuria: identification of the mutations of phenylalanine hydroxylase gene by PCR direct sequencing]

To investigate the mutations of the phenylalanine hydroxylase (PAH) gene in Orientals, direct sequencing was conducted on DNA fragments amplified by the polymerase chain reaction, using solid phase technology involving the biotin-streptavidin system. Four mutations possibly associated with phenylketonuria (PKU) were identified in a Chinese and four Japanese patients. A novel Arg158 (CGG)-to-Trp158 (TGG) mutation was identified in exon 5 of the PAH gene in a Chinese PKU patient. The second change was due to a G-to-A transversion at the last base of intron 4. The third change was a compound heterozygote; one mutation was a G-to-A transversion at the last base of intron 4. The other was a G-to-C transversion at the second base of codon 413, which resulted in a substitution of Arg(CGC) by Pro(CCC) in exon 12. The last change was due to a Tyr204(TAT) -to-cys204(TGT) mutation in exon 6 of the PAH gene in two Japanese. This preliminary study revealed a novel PKU mutation and considerable genetic heterogeneity in the PAH gene among Orientals.

[Detection of Campylobacter species by using polymerase chain reaction and nonradioactive labeled DNA probe]

We have detected Campylobacter species which are now recognized as major pathogens of acute diarrheal disease in humans using polymerase chain reaction (PCR) and a nonradioactive labeled DNA probe. Diagnosis of Campylobacter enteritis without doing culture from stool samples is of great benefit in the laboratory. Two oligonucleotide primers (20 mer) complementary to a unique sequence of the DNA encoding ribosomal RNA (rRNA) of Campylobacter jejuni for PCR were synthesized by solid-phase phosphoamidite method. Amplified target DNA of 275 base pairs could be resolved on ethidium bromide-stained gels, and hybridized with an oligodeoxynucleotide probe (28 mer) conjugated to alkaline phosphatase. In identification experiments, it was shown that the nonradioactive probe was hybridized to clinical strains of C. jejuni (104), C. coli (5), C. laridis (5), C. hyointestinalis (1) and C. fetus subsp. fetus (1) with an accuracy of 99-100%, while it was not for Helicobacter pylori. Further, there was no evidence of amplification in strains of K. pneumoniae, S. marcescens and E. coli. Using direct detection to stool specimens, this method could be performed in C. jejuni in 39 of 43 culture-positive specimens (91%), and in 19 of 141 culture-negative specimens (13.5%), respectively. The results of this comparative study suggested that the DNA probe assay became a rapid and reliable technique to confirm culture of Campylobacter species.

Serum erythropoietin concentrations and iron status in patients on chronic hemodialysis

We studied the relationship between serum erythropoietin (EPO) concentration and iron status in 67 patients undergoing chronic hemodialysis. Serum concentrations of EPO were measured by RIA with recombinant human EPO. The geometric mean of the serum EPO concentration was 10.9 int. units/L (mean +/- SD range = 7.8 - 15.3 int. units/L) in hemodialysis patients, considerably lower than that in normal subjects (12.9 int. units/L). We found no significant correlation between concentrations of serum EPO and hemoglobin in hemodialysis patients, but found a significant negative correlation between serum concentrations of EPO and iron in hemodialysis patients. Moreover, we also found a significant positive correlation between the EPO concentration and the unsaturated iron-binding capacity (UIBC) in serum, and a significant negative correlation between the serum concentrations of EPO and ferritin in hemodialysis patients. Several patients who had relatively high EPO concentrations for hemodialysis patients also had low iron concentrations, high UIBC values, and low ferritin concentrations. These findings suggest that iron was utilized even at these EPO concentrations, which were very low for the degree of anemia observed in the hemodialysis patients.

[An early cancer in adenoma of the papilla of Vater]

A 61-year-old male was admitted to our hospital with a complaint of epigastric discomfort and back pain. Chronic pancreatitis was suspected after an abdominal US study. Therefore, an ERCP study was performed. Macroscopically, the papilla of Vater showed an irregular shaped swelling. An ERCP X-ray revealed no abnormal findings, but biopsied specimens from the papilla showed a well differentiated adenocarcinoma in the adenoma, so that a pancreatoduodenectomy was performed. The lesion was 15 x 9 x 6 mm in size, and a histological examination revealed that a minor portion of the tumor was a carcinoma while the major portion was an adenoma, and the invasion as being d0 panc0 n0.

[A case of secondary linitis plastica of the colon developing 14 years after gastrectomy in advanced carcinoma]

A 59-year-old woman was admitted to our hospital complaining of weight loss. Fourteen years earlier, she had undergone gastrectomy for gastric carcinoma of the Borrmann III type on the lesser curvature of the body. Biopsy specimens of the lesion revealed poorly differentiated adenocarcinoma. On the fifth hospital day of the admission under study, she complained of vaginal bleeding, and a diagnosis of endometrial carcinoma was made by a gynecologist. Transverse colectomy and total hysterectomy were done. The lesion was localized only in the transverse colon, was histologically poorly differentiated adenocarcinoma similar to the specimen of gastric carcinoma resected 14 years earlier and involved mainly the serosa. Therefore, secondary linitis plastica of the transverse colon was diagnosed.