Intrachannel pulse interactions in dispersion-managed transmission systems: timing shifts

Nonlinear intrachannel interactions responsible for timing shifts in a transmission system with strong periodic dispersion management are investigated. Formulas describing the evolution of the timing shift are obtained for general bit patterns. When average dispersion is negligible, the timing shift is shown to grow linearly in distance in a system with loss and lumped amplification, whereas in a lossless system the timing shift is sufficiently small at every chirp-free point. The analysis agrees with direct numerical simulations.

Quasi-linear optical pulses in strongly dispersion-managed transmission systems

A unified analytical description of the evolution of quasi-linear optical pulses and solitons in strongly dispersion-managed transmission systems is developed. Asymptotic analysis of the nonlocal equation that describes the averaged dynamics of a dispersion-managed system shows that the nonlinearity decreases for large map strength s , as O(log s/s) . The spectral intensity is found to be an invariant of the propagation, which allows the phase shift to be computed. These findings provide a clear description of pulse propagation in the quasi-linear regime, which is characterized by much lower energies than those required for stable dispersion-managed soliton transmission with the same dispersion map.

Resonant nonlinear intrachannel interactions in strongly dispersion-managed transmission systems

Nonlinear intrachannel interactions in a transmission system with strong periodic dispersion management are studied. The ghost pulse at the zero bit is shown to grow resonantly as a result of periodic forcing and temporal phase matching with the signal pulses. The growth rate depends on the degree of overlap between the signals. The analysis agrees with direct numerical simulation of the full system. Growth rates for various bit patterns as a function of map strength are obtained.

The effect of occlusal appliances and clenching on the temporomandibular joint space

It has been suggested that stabilization appliances and mandibular anterior repositioning appliances work by decompressing the temporomandibular joint. To indirectly test this assumption, tomograms of right temporomandibular joints of seven subjects were taken during comfortable closure and maximum clenching in maximum intercuspation and on the two types of occlusal appliances. Outlines of the condyle and the temporal fossa were automatically determined by an edge detection protocol. Upon comfortable closure, the anterior joint space dimension was reduced with stabilization appliances and mandibular anterior repositioning appliances. Upon maximum clenching, the minimum joint space dimension on stabilization appliances was equivalent to that seen in maximum intercuspation, while that on mandibular anterior repositioning appliances was substantially less (P < .05). Findings do not indicate that these appliances induce an increase in joint space during clenching.

Adequacy and long-term prognosis of endoscopic carpal tunnel release

Forty-one hands of 37 patients with idiopathic carpal tunnel syndrome treated by endoscopic carpal tunnel release (ECTR) were followed up for more than one year after surgery. Surgical results were evaluated using Kelly's criteria, the Semmes-Weinstein test, the static and moving 2-point discrimination tests, tip-pinch strength, and motor and sensory nerve conduction studies. Clinical results, according to Kelly's criteria three months after surgery, were excellent or good in 36 hands, and fair or poor in five hands. No recovery was evident at six months and 12 months after surgery in fair and poor hands. Based on these findings, we conclude that a neurolysis of the median nerve and release of constriction of the thenar muscle branch should be performed using the conventional open technique for patients with poor results three months after ECTR if the patients are dissatisfied with ECTR results.

Chirped soliton interaction in strongly dispersion-managed wavelength-division-multiplexing systems

We theoretically analyze nonlinear interactions between chirped solitons in dispersion-managed wavelength-division-multiplexing (WDM) systems. We employ the perturbation method to evaluate frequency and chirp shifts caused by collisions among different WDM channels. It is shown that a chirped soliton suffers less frequency shift and time displacement than an ideal soliton, indicating its potential applicability for WDM systems.

Endoscopic carpal tunnel pressure measurement: a reliable technique for complete release

Carpal tunnel syndrome is diagnosed by clinical symptoms, Tinel's sign, Phalen's test and electromyography. Carpal tunnel pressure measurement can also aid in the precise identification of excessive pressure sites that indicate locations for release. In this study, pressure measurements made during endoscopic carpal tunnel release at 5 points were significantly higher anywhere in the carpal tunnel than outside the tunnel and decreased markedly after release. We concluded that our measurement technique can improve the reliability of endoscopic carpal tunnel release by decreasing the likelihood of missing any nerve entrapment sites.

Guyon's canal syndrome. A different clinical presentation caused by an atypical fibrous band

An atypical case of Guyon's canal syndrome is reported. A 40-year-old woman with hypoaesthesia and claw-finger deformity of the little finger, hypothenar muscle atrophy but no first dorsal interosseous muscle atrophy, underwent release of a fibrous band to decompress the ulnar nerve at the deep branch just proximal to the branch to the abductor digiti minimi muscle. The claw-finger deformity recovered 1 week after surgery.

Synthesis and release of glycosylated prolactin in transfected cells with human prolactin complementary deoxyribonucleic acid

To analyze how the synthesis and release of glycosylated PRL (G-PRL) is regulated, we transfected human PRL complementary deoxyribonucleic acid (cDNA) into three different cell lines consisting of GH3 cells that originated in rat pituitary tissue, Chinese hamster ovary cells, and COS-1 cells generated from monkey renal tissue. 35S-labeled PRLs produced by the cells were immunoprecipitated with anti-human PRL antiserum, and the ratios of G-PRL to total PRL were compared. PRLs of 23 kDa and 25 kDa were detected in the cell lysate and medium. The 25-kDa PRL was confirmed to be a glycosylated form by endoglycosidase treatments. The ratios of G-PRL/total PRL were 0.17-0.33, which were similar in lysates and media and among different cell lines. Pulse-chase experiments revealed that the autonomaous secretion rates of G-PRL and non-glycosylated PRL were almost identical. These results indicate that synthesis and secretion kinetics of human PRL may not be affected by its glycosylation in the cells transfected with PRL cDNA.

Delayed posterior interosseous nerve palsy

A rare case of delayed posterior interosseous nerve palsy that developed 39 years after an unreduced anterior dislocation of the radial head is reported. The posterior interosseous nerve was compressed and narrowed at the arcade of Frohse. Radial head resection and release of the arcade was done. The paralysis continued to recover 6 weeks after operation. The nerve, at the arcade of Frohse, was susceptible to compression by the dislocated radial head, especially in the supinated position. Repeated supination and pronation movement over time may have led to developmental changes that caused the delayed nerve palsy.

[Newly developed detection system for serum Helicobacter pylori antibodies using ELISA and its clinical significance]

Using ELISA, a specific and sensitive system that detects serum immunoglobulin G antibodies against all soluble antigens of Helicobacter pylori (Hp) has been developed. This system is used at three different concentrations of Hp antigens coated on the solid phase of the ELISA. Anti-Hp antibodies were judged positive when the difference in the ELISA values between high and middle or middle and low concentrations of antigen were over the specific values. For the ELISA system, called the three point antigen method, sensitivity and specificity of urease activity were 86.9% and 70.8%, respectively. Positive rate for antibodies to serum Helicobacter pylori in dyspeptic patients was higher than that in healthy subjects.

Polypoid growth and K-ras codon 12 mutation in colorectal cancer

BACKGROUND

To clarify genetic changes in colorectal tumorigenesis, K-ras codon 12 point mutations were examined in 101 ordinary colorectal carcinomas and 6 that complicated ulcerative colitis (UC) with special attention to growth patterns.

METHODS

The depths of invasion of ordinary carcinoma were submucosa (SMCa) in 39 cases, muscularis propria (PMCa) in 33, and far-advanced in 29. Growth patterns of SMCa and PMCa were classified into three types: polypoid-growth type without central depression (Type 1), polypoid-growth type with central depression (Type 2), and nonpolypoid-growth type. DNA samples were extracted from formalin fixed paraffin embedded sections, and K-ras codon 12 mutations were examined by two-step polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

K-ras mutation frequency was higher in Type 1 SMCa than in nonpolypoid SMCa, 56% (9/16) versus 6% (1/17), respectively, and in PMCa, 78% (7/9) versus 23% (3/13), respectively. In 6 UC carcinomas, a K-ras mutation was detected in only one polypoid carcinoma and none were detected in five nonpolypoid carcinomas.

CONCLUSIONS

These results and the authors' previous study suggest that nonpolypoid carcinomas may be derived from flat adenomas, whose K-ras mutation incidence also was low, and this pathway is different from a genetic model based on the ordinary adenoma-carcinoma sequence through polypoid adenomas.

Polypoid growth and K-ras codon 12 mutation in colorectal cancer

BACKGROUND

To clarify genetic changes in colorectal tumorigenesis, K-ras codon 12 point mutations were examined in 101 ordinary colorectal carcinomas and 6 that complicated ulcerative colitis (UC) with special attention to growth patterns.

METHODS

The depths of invasion of ordinary carcinoma were submucosa (SMCa) in 39 cases, muscularis propria (PMCa) in 33, and far-advanced in 29. Growth patterns of SMCa and PMCa were classified into three types: polypoid-growth type without central depression (Type 1), polypoid-growth type with central depression (Type 2), and nonpolypoid-growth type. DNA samples were extracted from formalin fixed paraffin embedded sections, and K-ras codon 12 mutations were examined by two-step polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

K-ras mutation frequency was higher in Type 1 SMCa than in nonpolypoid SMCa, 56% (9/16) versus 6% (1/17), respectively, and in PMCa, 78% (7/9) versus 23% (3/13), respectively. In 6 UC carcinomas, a K-ras mutation was detected in only one polypoid carcinoma and none were detected in five nonpolypoid carcinomas.

CONCLUSIONS

These results and the authors' previous study suggest that nonpolypoid carcinomas may be derived from flat adenomas, whose K-ras mutation incidence also was low, and this pathway is different from a genetic model based on the ordinary adenoma-carcinoma sequence through polypoid adenomas.

Polypoid growth and K-ras codon 12 mutation in colorectal cancer

BACKGROUND

To clarify genetic changes in colorectal tumorigenesis, K-ras codon 12 point mutations were examined in 101 ordinary colorectal carcinomas and 6 that complicated ulcerative colitis (UC) with special attention to growth patterns.

METHODS

The depths of invasion of ordinary carcinoma were submucosa (SMCa) in 39 cases, muscularis propria (PMCa) in 33, and far-advanced in 29. Growth patterns of SMCa and PMCa were classified into three types: polypoid-growth type without central depression (Type 1), polypoid-growth type with central depression (Type 2), and nonpolypoid-growth type. DNA samples were extracted from formalin fixed paraffin embedded sections, and K-ras codon 12 mutations were examined by two-step polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

K-ras mutation frequency was higher in Type 1 SMCa than in nonpolypoid SMCa, 56% (9/16) versus 6% (1/17), respectively, and in PMCa, 78% (7/9) versus 23% (3/13), respectively. In 6 UC carcinomas, a K-ras mutation was detected in only one polypoid carcinoma and none were detected in five nonpolypoid carcinomas.

CONCLUSIONS

These results and the authors' previous study suggest that nonpolypoid carcinomas may be derived from flat adenomas, whose K-ras mutation incidence also was low, and this pathway is different from a genetic model based on the ordinary adenoma-carcinoma sequence through polypoid adenomas.

Lower incidence of K-ras codon 12 mutation in flat colorectal adenomas than in polypoid adenomas

In order to clarify genetic changes in flat adenomas, K-ras codon 12 point mutations were examined in 56 flat adenomas, 81 polypoid adenomas and 42 cancers of colon and rectum. The mutation frequency in flat adenomas was 23% (13/56), significantly lower than that in polypoid adenomas (67%: 54/81) and cancers (76%: 32/42). Even mildly dysplastic adenomas or small (less than 5 mm) adenomas showed higher mutation incidence in polypoid type (62%, 57%) than in flat type (23%, 19%). Among flat adenomas, flat elevated lesions exhibited relatively higher mutation frequency than completely flat or depressed ones. As for cancers, 14 tumors (33%) contained mutations only in a minor tumor cell population, indicating that these mutations occur at a late stage of tumorigenesis. These results suggest that the adenoma-carcinoma sequence through flat adenomas may be different from that through polypoid adenomas, and genetic changes may be heterogeneous in colorectal carcinogenesis.

Inhibition of 7,12-dimethylbenz[a]anthracene-induced lipid peroxidation and mammary tumor development in rats by vitamin E in conjunction with selenium

The effects of combined dietary vitamin E supplementation and a relatively low increase in selenium levels on 7,12-dimethylbenz[a]anthracene (DMBA) induction of lipid peroxidation in the short term and development of mammary tumors in the long term were investigated in female Sprague-Dawley rats. Control animals were fed the basal diet (20 mg/kg vitamin E and 0.6 mg/kg selenium) throughout the experiment. Three other groups received a high vitamin E diet (235 mg/kg vitamin E and 0.6 mg/kg selenium) at different times, the first two from three weeks after DMBA treatment and the other throughout the experiment. When the vitamin E diet with selenium supplementation was applied until three weeks after DMBA or until the termination of the experiment, tumor yields (tumors per rat) were significantly inhibited compared with the control group. On the other hand, delaying the supplementation of vitamin E until three weeks postcarcinogen produced no prophylactic effect. The elevation of lipid peroxidation levels observed immediately after DMBA administration was also significantly inhibited in both mammary fat pads and livers of animals in the high vitamin E group. It was therefore concluded that the inhibitory effect of vitamin E in combination with selenium on tumorigenesis might be causally related to reduction of carcinogen treatment associated with lipid peroxidation, the latter presumably playing an important role in DMBA-induced mammary carcinogenesis.

Microassay for GM1 ganglioside beta-galactosidase activity using high-performance liquid chromatography

A simple and sensitive assay for GM1 ganglioside (GM1) beta-galactosidase activity was devised by direct measurement of released D-galactose using high-performance liquid chromatography (HPLC). GM1 beta-galactosidase activity in crude samples such as brain homogenates could be measured by this method. After incubation of brain homogenate for 1 h with GM1 at 37 degrees C and pH 4.4 in the presence of sodium taurodeoxycholate, the reaction was terminated by heating at 100 degrees C for 2 min and the supernatant from the centrifuged sample was analysed directly by HPLC. D-Galactose isolated by HPLC was converted into a fluorescent compound by a post-column reaction with arginine at 150 degrees C and the fluorescence intensity at 430 nm was measured with excitation at 320 nm. By this method 10 pmol of D-galactose could be measured and the fluorescence intensity was linear up to 1 mmol of D-galactose. Using this method, the optimal conditions for the activity of this enzyme were re-examined. As an application, the enzyme activity in the brain of a patient with GM1 gangliosidosis was examined. This method can be applied to any natural substrates, glycolipids or glycoproteins, the terminal galactose of which is hydrolysed by this enzyme.

Molecular characterization of the virC genes of the Ti plasmid

The virC (formerly bak) complementation group of the nopaline-type Ti plasmid pTiC58 encodes two proteins, VirC1 and VirC2. According to the primary structure of the polypeptides predicted by the nucleotide sequence, VirC1 is composed of 231 amino acids with a total molecular mass of 25.5 kilodaltons, and VirC2 is composed of 202 amino acids with a molecular mass of 22.1 kilodaltons. The pTiC58 VirC1 and VirC2 polypeptides are equal in length to VirC1 and VirC2 of the octopine-type plasmid pTiA6NC. VirC1 proteins of pTiC58 and pTiA6NC are identical at 202 (87.4%) of the amino acid residues, and this homology is distributed fairly evenly throughout the protein. VirC2 identities occur at 142 residues (70.3%), but fall predominantly into two blocks of higher homology (84.6 and 78.5%) separated by a 41-residue segment of much lower homology (29.3%). Mutations in virC resulted in attenuated virulence on all hosts tested, the severity of attenuation varying markedly depending on the type of plant inoculated. For example, the attenuation was more pronounced on Kalanchoe than on sunflower or jimson weed. Virulence was restored to normal on all hosts by in-trans complementation with corresponding nonmutant DNA fragments of pTiC58 or of the octopine-type plasmid pTi15955. Two oligopeptides from within the predicted pTiC58 VirC1 polypeptide were synthesized and used to raise antibodies. These antibodies were used to detect the VirC1 product of both pTiC58 and pTi15955. In both cases, virC was expressed constitutively in the Agrobacterium tumefaciens ros mutant. The homology between virC genes of octopine- and nopaline-type Ti plasmids thus includes a conservation of genetic regulatory control mechanisms as well as considerable conservation of the primary structure of the protein products.

Characterization of the virE locus of Agrobacterium tumefaciens plasmid pTiC58

The virE locus that is responsible for the efficiency of infection by Agrobacterium tumefaciens (T. Hirooka and C. Kado, J. Bacteriol. 168:237-243, 1986) is located next to the right boundary of the virulence (Vir) region of the nopaline plasmid pTiC58. This locus is very similar to the virE locus of octopine type Ti plasmids on the basis of nucleotide and amino acid sequence comparisons as well as genetic complementation analyses. The nucleotide sequence of virE revealed three open reading frames, arranged as an operon, with a potential coding capacity for proteins of 9, 7.1, and 63.5 kilodaltons. The promoter region of virE was analyzed by using gene fusions to promoterless cat and lux genes. Two different promoters were detected, one which operates in A. tumefaciens and one which operates in Escherichia coli. virE is transcribed from left to right toward the T region. In A. tumefaciens, the expression of virE was induced by acetosyringone and required the presence of pTiC58.

Location of the right boundary of the virulence region on Agrobacterium tumefaciens plasmid pTiC58 and a host-specifying gene next to the boundary

The right boundary of the virulence (Vir) region of the nopaline plasmid pTiC58 of Agrobacterium tumefaciens was determined by transposon insertion, cartridge emplacement, and deletion mutagenesis. Genetic complementation with mutant and wild-type alleles led to the identification of the virE locus at the right boundary, which was located about 6 kilobases from the left border of the segment of DNA that is transferred into the plant genome. virE is 2.0 kilobases long and encodes at least one protein of 69 kilodaltons. Various mutations in virE resulted in different truncated lengths of the 69-kilodalton protein. As this protein was increasingly truncated from the carboxy terminus, the host range of A. tumefaciens and the frequency of tumor formation diminished concomitantly. Thus, as one of its functions, the 69-kilodalton protein of virE is probably involved in some aspect of the host range specificity of A. tumefaciens and in infection efficiency.

Endoscopic bipolar electrocoagulation in upper gastrointestinal bleeding

A new endoscopically deliverable bipolar electrocoagulator has been developed, and employed clinically to treat upper gastrointestinal bleeding in 53 patients on 61 occasions. By direct application of the electrode to the bleeding vessels immediate hemostasis was achieved in 52 out of 53 bleeding vessels. Non-bleeding visible vessels were safely coagulated. Arrest of bleeding was permanent in 44 patients (83%), of whom 20 were candidates for emergency operation because of massive, continued or recurrent bleeding. Rebleeding after hemostasis by bipolar electrocoagulation was noted in 8 patients (15%); however, the majority of rebleeds were those with acute mucosal lesions who had serious underlying medical problems. Emergency operation was performed in 5 patients, and was averted in most patients after successful hemostasis by bipolar electrocoagulation. There were no complications related to the procedure. Bipolar electrocoagulation with our coagulator is a safe and easily applicable technique that is a promising addition to currently available endoscopic hemostatic methods.

Effect of beta-glucuronidase inhibitor on azoxymethane-induced colonic carcinogenesis in rats

In this study of the role of microfloral beta-glucuronidase in colonic carcinogenesis, the effect of beta-glucuronidase inhibitor was evaluated. Starting at 5 weeks of age, male Donryu rats were fed either a semisynthetic diet or the same diet containing 0.1% beta-glucuronidase inhibitor as N-cyclohexyl-5-O-acetyl-2,4-O-p-methoxybenzylidene) -D-glucaro-1-amide-6,3-lactone (C-GAL). All animals were given s.c. injections of 7.4 mg azoxymethane (AOM) per kg body weight once a week for 11 weeks and followed for an additional 20 weeks. Most animals receiving the colonic carcinogen developed tumors in the colon, and a few also developed tumors in the small intestine. However, the number of tumors in the large intestine of the rats given C-GAL at the same time as AOM was significantly lower than in the control rats, especially in the proximal half of the colon, but those given C-GAL after AOM treatment had almost the same number of colon tumors as did the controls. It is concluded that, since bacterial beta-glucuronidase activity in the feces of rats given 0.1% C-GAL was significantly inhibited, intestinal microfloral beta-glucuronidase may play an important role in colonic carcinogenesis caused by AOM.