Creation of Electron-Positron Pairs in Photon-Photon Collisions Driven by 10-PW Laser Pulses.

A novel approach is proposed to demonstrate the two-photon Breit-Wheeler process by using collimated and wide-bandwidth γ-ray pulses driven by 10-PW lasers. Theoretical calculations suggest that more than 3.2×10^{8} electron-positron pairs with a divergence angle of 7° can be created per shot, and the signal-to-noise ratio is higher than 10^{3}. The positron signal, which is roughly 100 times higher than the detection limit, can be measured by using the existing spectrometers. This approach, which could demonstrate the e^{-}e^{+} pair creation process from two photons, would provide important tests for two-photon physics and other fundamental physical theories.

High-efficiency γ-ray flash generation via multiple-laser scattering in ponderomotive potential well.

γ-ray flash generation in near-critical-density target irradiated by four symmetrical colliding laser pulses is numerically investigated. With peak intensities about 10^{23} W/cm^{2}, the laser pulses boost electron energy through direct laser acceleration, while pushing them inward with the ponderomotive force. After backscattering with counterpropagating laser, the accelerated electron is trapped in the electromagnetic standing waves or the ponderomotive potential well created by the coherent overlapping of the laser pulses, and emits γ-ray photons in a multiple-laser-scattering regime, where electrons act as a medium transferring energy from the laser to γ rays in the ponderomotive potential valley.

[Preterm ovarian hyperstimulation syndrome: a case report and literature review].

OBJECTIVE: To discuss the clinical characteristics, pathogenesis, diagnosis and treatment of preterm ovarian hyperstimulation syndrome(POHS). METHOD: The process of diagnosis and treatment of a test-tube female baby were summarized. She was deliveried at 32(+ 2) weeks of gestation, diagnosed with POHS, and born in the First Affiliated Hospital of Wenzhou Medical University(in 2015). Retrieval of related literature in PubMed database and Wanfang database was performed using the key words"ovarian hyperstimulation syndrome"and"preterm infants or newborns"from 1980 to 2015. RESULT: The patient developed labial hyperemia and edema, ectropion of vaginal mucosa and plica, swelling of the hypogastrium and upper legs at 41 days (38(+ 1) weeks post-conception). The child was continuously observed because diagnosis was not clear. The pelvic and abdominal ultrasonography examinations revealed a cyst in the right ovary and laboratory evaluation of the baby showed high concentrations of gonadotropin and estradiol at 49 days (39(+ 2) weeks post-conception), and thus the baby was diagnosed with POHS. With no special intervention measures, the baby became normal at 169 days (4 months post-conception). Six papers from foreign literature were retrieved and none from Chinese literature, which reported 12 cases of POHS. They all characterized prematurity, ovarian cyst/cysts, labial hyperemia and edema, swelling of the hypogastrium and upper leg, high serum gonadotropin and estradiol levels at 35 to 39 weeks post-conception, including 3 cases with breast enlargement, 1 case with vaginal bleeding and 1 case with ectropion of vaginal mucosa and plica. The treatments included in 1 case combined surgery with pharmacological intervention, in another case only pharmacological intervention, and in the others no interventional measures were taken but were only followed up. As for the results, the baby with the surgical treatment had recurrence, but the symptoms, ovarian cyst and hormone concentration of the other babies gradually became normal in 4-5 months. CONCLUSION: POHS is a rare and self-limiting disease. The common clinical features of this disease are prematurity, ovarian cyst or cysts, labia hyperemia and edema, swelling in the hypogastrium and upper legs, high serum gonadotropin and estradiol levels at 35 to 39 weeks post-conception. It does not require treatment if there is no complication, but follow-up is necessary.

In vivo on-line HPLC-microdialysis: simultaneous detection of monoamines and their metabolites in awake freely-moving rats.

An on-line microbore high performance liquid chromatographic--electrochemical (HPLC--EC) detection method has been developed for the simultaneous measurement of dopamine (3,4-dihydroxyphenethylamine, DA), its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (3-methoxy-4-hydroxyphenylacetic acid, HVA), as well as serotonin (5-hydroxytryptamine, 5-HT) and its metabolise 5-hydroxyindole-3-acetic acid (5-HIAA) in the striatum of awake and freely moving rats. Our method was capable of detecting DOPAC, 5-HIAA, HVA, DA and 5-HT at retention time of 3, 5, 6.5, 9, and 24 min, respectively, in repeated on-line microdialysis sampling. Analysis was performed using a 150 x 1 mm 5 microm C18 microbore column attached directly to a thin-layer radial flow electrochemical cell (UniJet) comprising a 6 mm glassy carbon working electrode. In order to accommodate signal outputs (due to a varying level in the neurochemicals under investigation), an amperometric detector was equipped with a sensitivity programmable controlling software for automatically switching sensitivity inattentively and repeatedly for each collection cycle.

Effects of tamoxifen on striatal dopamine and 5-hydroxytryptamine release in freely moving male rats: an in-vivo microdialysis investigation.

Recent studies indicating interaction of oestrogens with central cholinergic, dopaminergic and 5-HTergic systems have led to the assumption of a protective role of oestrogens in certain neurodegenerative disorders. The non-steroidal drug tamoxifen, a mixed oestrogen agonist-antagonist, has been shown to modulate central nervous system functions in the corpus striatum. In this study we used a microdialysis technique to examine the effects of tamoxifen upon the striatal dopaminergic and 5-HTergic systems in intact freely moving male rats. The extracellular levels of dopamine, 3,4-dihydroxyphenylacetic acid, homovanillic acid and 5-hydroxyindoleacetic acid were measured after intraperitoneal administration of either the control or tamoxifen, and were compared with their corresponding baseline levels. Significant 25-35% increases in the baseline levels of dopamine and 3,4-dihydroxyphenylacetic acid were observed after the highest doses of tamoxifen (1.5 mg kg(-1) and 30 mg kg(-1), respectively), whereas the lowest dose of tamoxifen (0.3 mg kg(-1)) elevated dopamine and 3,4-dihydroxyphenylacetic acid levels by a detectable 15% of the basal. In addition, the ratio of 3,4-dihydroxyphenylacetic acid-to-dopamine remained unchanged in comparison with that of the pretreatment levels. Whereas no change in the striatal 5-hydroxyindoleacetic acid concentrations was seen with the lowest and highest dose regimen, the intermediate dose elicited a moderate increase (20%) in basal 5-hydroxyindoleacetic acid levels. The pharmacological relevance of the effects of tamoxifen on the dopaminergic and 5-HTergic systems, as a prelude to the development of non-steroidal oestrogenic compounds in reducing the risk of neurodegenerative disorders such as Alzheimer's disease, is discussed.

Snail hosts of Paragonimus in Asia and the Americas.

We have undertaken a comprehensive review of snail hosts of Paragonimus world-wide exclusive of Africa based on modern malacological data, where available, and with consideration of the phylogeny of the snail groups involved. This is the first comprehensive review since those made by Chen (1979) and Chen et al. (1983), and there have been considerable taxonomic changes over the past decade. A number of names and concepts found in the medical malacological and parasitological literature up to the present time require revision or correction. There are vast radiations of snails of the superfamilies Cerithiacea and Rissoacea involved in the transmission of Paragonimus in China. We list 54 species world-wide of which 35(65%) occur in China. Revisions and corrections pertaining to China include: (i) The family Hydrobiidae does not occur in China or S.E. Asia, and the Pomatiopsidae should be used. (ii) The genus Bythinella is entirely European (Hydrobiidae: Amnicolinae). The so-called Bythinella of China belongs to the genus Erhaia (Pomatiopsidae). (iii) The generic name Pseudobythinella described from China is preoccupied, a junior synonym of Pseudobythinella Melville 1956, a fossil from England. All Chinese Pseudobythinella are now classified as Erhaia. (iv) Akiyoshia has been used as a generic name for some snails in Hunan transmitting Paragonimus. Akiyoshia is from Japan and biological/ecological data indicate that the Chinese taxon is not Akiyoshia. (v) The genus Tricula in recent Chinese literature is comprised of four genera determined by detailed comparative anatomical data: Tricula, Neotricula, Gammatricula, and Jinhongia. Shells cannot be used to discriminate among them. (vi) Tricula cristella has been consistently misidentified in collections in China and literature. However, genuine T. cristella does transmit Paragonimus skrjabini. (vii) Tricula minutoides in the Chinese literature has been misidentified, and specimens are T. cristella. (viii) The genus Melania and the family Melaniidae are used in the Chinese literature. The so-called melaniidae snails belong to the families Thiaridae, Pleuroceridae, and Melanopsidae. Asian Semisulcospira is pleurocerid while Melanoides and Tarebia are thiarid (ix) Semisulcospira libertina is correctly identified for populations ranging throughout Japan to Taiwan. This species is most probably not distributed throughout all south China, and intense systematic research on Semisulcospira is needed. A modern classification is given for snails transmitting Paragonimus.

Delayed brachial plexus neurapraxia complicating malunion of the clavicle.

Delayed brachial plexus neurapraxia is a rare complication of midshaft clavicular fracture. The symptoms are variable and occur insidiously. Surgical decompression to release the compression of brachial plexus is the treatment of choice and usually has a good result. We report a patient whose brachial plexus was compressed by malunion of the clavicle. This patient had a good outcome after treatment with intramedullary nailing and Knowles pin fixation after corrective osteotomy without bone grafting.

[Serological cross reaction between schistosomiasis japonica and pagumogonimiasis skrjabini].

The sera from 25 patients with acute, 36 patients with chronic schistosomiasis japonica and 68 patients with pagumogonimiasis skrjabini were tested against SEA, schistosome egg, Paragonimus adult antigen (PAA) and Paragonimus metacercaria using different tests including biotin-avidin system (BAS), ELISA, circumoval precipitate reaction (COPT) and metacercaria membrane reaction (MCMR). Results showed: 1. The specific reactions using PAS and ELISA were (1) both 100% in acute schistosomiasis patients (ASP), (2) 100% and 97.2% respectively in chronic schistosomiasis patients (CSP) and (3) both were 98.5% in paragonimiasis patients (PP). 2. The cross reactions using BAS, ELISA and MCMR were (1) 76%, 72% and 20% respectively in ASP, (2) 27.8%, 22.2% and 19.4% respectively in CSP. 3. The cross reactions using BAS, ELISA and COPT were 26.5%, 30.9% and 8.8% respectively in PP. 4. The frequency of cross reaction was related to the sensitivity of the test used. 5. The frequency of cross reaction in ASP was remarkably lower with MCMR than with BAS or ELISA. 6. The frequency of cross reaction in CSP was related to the intensity of infection. 7. We suggest that more than one test should be carried out in patients who showed cross reaction to a single test, then the frequency of cross reaction would decline.

[Common antigenic components in soluble antigens shared by Schistosoma japonicum eggs and Paragonimus westermani adult worms].

Using enzyme-linked immunoblot technique (ELIB), the antigenic protein components of water-soluble and urea-soluble antigens of Schistosoma japonicum eggs (JSEA, JEAU) and Paragonimus westermani adult worms (PAA, PAA-U) were analysed. The results showed that in both JSEA and JEA-U, 8 and 3 bands of polypeptides could be recognized by sera from patients with schistosomiasis japonica (Sj). In both PAA and PAA-U, there were 9 and 2 bands of polypeptides respectively, which could be recognized by sera from patients with pagumogonimiasis skrjabini (Ps). The components of 36/37kDa in PAA and 20/21 kDa in JSEA were identified to be shared antigenic fractions existing between the two species of trematodes, which gave positive reaction against patient's sera from both S.j. and P.s., while PAA-U caused the reaction only with sera from patients with acute schistosomiasis. PAA-U might be useful to avoid cross reaction in the majority of schistosomiasis patients in the fields.

[Comparison of the repetitive DNA sequences between Paragonimus westermani and Pagumogonimus skrjabini from six areas].

The genomic DNA of the two lung flukes (P. westermani and P. skrjabini) from six areas was digested separately by three restriction endonucleases BamHI, Hae III and Hind III, followed by agarose gel electrophoresis. Repetitive DNA were visualized as distinct bands in stained gels. Restriction fragment length differences were detected between the two species. The majority of bands of repetitive DNA were similar with minor differences within the same species collected from different areas, upon digestion with certain restriction endonucleases. The results demonstrated that the technique for demonstrating the band pattern of repetitive DNA with three restriction endonucleases can be used for the identification of P. westermani and P. skrjabini and the geographic relationship of the same species from different areas (Figs. 1-3).

Reimplantation of infected hip arthroplasties using bone allografts.

Twenty-two patients with deep infection of an hip prosthesis received delayed reimplantation using bone allografts. Sixteen were done using noncemented components and 6 using femoral components that were fixed with antibiotic impregnated cement. Bulk allografts were used at the acetabular site in 2 patients and at the femoral site in 4 patients. Morselized allografts were used at the acetabular site in 20 patients and at the femoral site in 10 patients. The causative organisms were virulent in 10 hips and low virulent in 12 hips. At an average followup of 4 years (range, 2-7 years), 91% of patients were free of infection and 73% had a successful functional result. Two had a recurrent infection; 1 of them had a pseudomonas infection and another had a methicillin resistant Staphylococcal infection. The recurrence of infection tended to be higher if the causative organism was virulent. The use of bone allografts at the staged reimplantation of the infected hip arthroplasty did not increase the incidence of recurrent infection. Both cemented and noncemented reimplantations had a successful result in eradicating the infection. However, hybrid reimplantation with a cemented femoral component and fixed porous acetabular component had a better functional outcome than noncemented reimplantation using porous femoral component and nonfixed acetabular component.

Surgical treatment of muscular torticollis for patients above 6 years of age.

Eighteen patients with congenital muscular torticollis, aged 6-22 (average 11) years, underwent surgical releases of the contractive bands. There were 8 boys and 10 girls. Preoperative open mouth radiograph of the odontoid process in 16 patients showed asymmetry of articular facets of the axis and tilt of the odontoid process to the side of the torticollis. Sixteen patients received bipolar releases, the others received distal releases. After the operation, a neck collar was applied and an exercise program was started. At an average follow-up of 5 years and 7 months, there were excellent or good results in 10 patients. All of the patients except 2 showed improvement of the facial asymmetry and all except 1 had a satisfactory range of motion of the neck. One patient underwent a second operation due to recurrence. The follow-up radiographs showed improvement of the tilt of the odontoid process, but the asymmetry of the articular facets of the axis persisted. We suggest that bipolar release is the treatment of choice for congenital muscular torticollis in patients of more than 6 years of age. To determine the influence of a bipolar release on the functions of the cervical spine, longer follow-up intervals are needed.

Controlled comparison of two fluorometholone formulations in the antigen challenge model of allergic conjunctivitis.

We compared the safety and efficacy of MethaSite, a gel-forming suspension (0.1% fluorometholone), to a commercially available 0.1% fluorometholone ointment, FML S.O.P., using an antigen challenge model. Subjects with known allergic histories were exposed to increasing concentrations of cat dander, ragweed, or grass at visits 1 and 2. Allergic responses of conjunctival injection, chemosis, and subjective itching were quantified on a scale from zero to 3; the sum of these ratings constituted the total allergic score. At visit 3, 105 subjects with total scores of > or = 5 received a drop of MethaSite in one eye and a 0.5 inch ribbon of FML ointment in the other eye. Three and 6 hours postdose, the eyes were challenged with the antigen concentration that provoked significant allergic response at visit 2. We determined safety by evaluating changes in visual acuity, intraocular pressure, and biomicroscopy that occurred between visits 1 and 3. Eyes treated with MethaSite and FML responded similarly to the antigen challenges. Both groups demonstrated suppression of allergic response 3 and 6 hours postdose through equivalent and significant reductions in total allergy scores and individual ratings of injection, chemosis, and itching. In this population, MethaSite was equivalent to FML ointment in safety and efficacy.

Bilateral pathological femoral neck fractures secondary to ectopic parathyroid adenoma.

A rare case of bilateral pathological femoral neck fractures secondary to ectopic parathyroid adenoma is reported. Both hip fractures were treated with closed reduction and internal fixation. The right hip fracture healed uneventfully, whereas the left hip fracture developed non-union that required subtrochanteric osteotomy and internal fixation and eventually healed. Neither hip developed avascular necrosis.

Acute septic arthritis of the hip in children.

Thirty-three cases of acute septic arthritis of the hip in children were treated at our hospital from 1986 to 1997. The average follow-up period was 6 years (range 2-11 years). In 17 cases the right hip was affected, and in 16 the left hip. The average duration of symptoms was 5 days (range 1-14 days). Microorganisms were isolated from the blood, joint aspirate, or surgical specimens in 25 cases (76%). Staphylococcus aureus was the most common bacteria found (44%). Those patients with S. aureus infection were older than 1 year of age. There was no significant difference in the final outcome between the younger and the older age groups. Twenty-six out of 33 patients (89%) had a satisfactory outcome. Satisfactory results can also be expected with arthrocentesis and medical treatment if the diagnosis is made early, and antibiotic treatment affords a good clinical response. Four out of 7 cases with an unsatisfactory result were associated with osteomyelitis of the proximal femur. The two most important factors associated with poor results included a delay of definite treatment lasting longer than 5 days and the presence of osteomyelitis of the proximal femur.

Treatment of nonunions of long bone fractures with shock waves.

A prospective clinical study investigated the effectiveness of shock waves in the treatment of 72 patients with 72 nonunions of long bone fractures (41 femurs, 19 tibias, seven humeri, one radius, three ulnas and one metatarsal). The doses of shock waves were 6,000 impulses at 28 kV for the femur and tibia, 3,000 impulses at 28 kV for the humerus, 2,000 impulses at 24 kV for the radius and ulna, and 1,000 impulses at 20 kV for the metatarsal. The results of treatment were assessed clinically, and fracture healing was assessed with plain radiographs and tomography. The rate of bony union was 40% at 3 months, 60.9% at 6 months, and 80% at 12 months followup. Shock wave treatment was most successful in hypertrophic nonunions and nonunions with a defect and was least effective in atrophic nonunions. There were no systemic complications or device-related problems. Local complications included petechiae and hematoma formation that resolved spontaneously. In the authors' experience, the results of shock wave treatment were similar to the results of surgical treatment for chronic nonunions with no surgical risks. Shock wave treatment is a safe and effective alternative method in the treatment of chronic nonunions of long bones.

Influencing factors and ambulation outcome in patients with dual disabilities of hemiplegia and amputation.

OBJECTIVE: To determine the ambulatory outcome and predictive factors of successful ambulation training in patients with both hemiplegia and lower extremity amputation. DESIGN: A retrospective study. SETTING: A rehabilitation center of a university hospital. PATIENTS: Twenty-three patients with dual disabilities consecutively admitted to the rehabilitation center from 1984 to 1994. MAIN OUTCOME MEASURES: Ambulatory outcome was measured using physical therapists' and physicians' notes at discharge or the last available clinical visit. Ambulation ability was graded as community and noncommunity ambulation, which included indoor ambulation and nonambulation. Several clinical features were reviewed to assess their association with ambulation outcome. RESULTS: About two thirds of the 23 patients could be trained to be ambulatory: 10 (43.8%) achieved community ambulation and 5 (21.7%) achieved indoor ambulation. Of the clinical factors, only mental status showed a statistically significant association with good ambulation outcome (p<.05). When odds ratios were considered, several factors, including mild motor involvement, transtibial amputation, amputation before cerebrovascular accident, age younger than 60 years, and the presence of ipsilateral hemiplegia and amputation, showed trends toward association with increased ambulation achievement, although these associations were not statistically significant. CONCLUSION: Impaired mental status seemed to be the most influential negative predictive factor of achieving community ambulation. If subjects with dual disabilities are properly selected, satisfactory results of ambulation training will be obtained.

GABAergic attenuation of cocaine-induced dopamine release and locomotor activity.

GABA modulates dopamine concentrations in the nucleus accumbens and corpus striatum. Using in vivo microdialysis techniques we examined this modulatory role and the extent to which three different GABAergic drugs can attenuate cocaine's ability to increase extracellular dopamine concentrations and gross locomotor activity. Ethanol, lorazepam (Ativan), and gamma-vinyl GABA (GVG) significantly and dose-dependently attenuated cocaine-induced dopamine release in the corpus striatum of freely moving animals. Unlike ethanol or lorazepam, however, GVG is not a sedative hypnotic in the doses used, and hence the strategy of selectively increasing GABAergic activity by suicide inhibition of the catabolic enzyme, GABA-transaminase, offers the unique advantage of attenuating cocaine-induced dopamine release without the apparent side effects typically associated with sedative hypnotics.