High-Flux Femtosecond X-Ray Emission from Controlled Generation of Annular Electron Beams in a Laser Wakefield Accelerator

Annular quasimonoenergetic electron beams with a mean energy in the range 200-400 MeV and charge on the order of several picocoulombs were generated in a laser wakefield accelerator and subsequently accelerated using a plasma afterburner in a two-stage gas cell. Generation of these beams is associated with injection occurring on the density down ramp between the stages. This well-localized injection produces a bunch of electrons performing coherent betatron oscillations in the wakefield, resulting in a significant increase in the x-ray yield. Annular electron distributions are detected in 40% of shots under optimal conditions. Simultaneous control of the pulse duration and frequency chirp enables optimization of both the energy and the energy spread of the annular beam and boosts the radiant energy per unit charge by almost an order of magnitude. These well-defined annular distributions of electrons are a promising source of high-brightness laser plasma-based x rays.

[Assignments of 1HNMR fingerprint of the root bark of Celastrus angulatus]

AIM

To assign the 1HNMR finger-print of the root bark of Celastrus angulatus.

METHODS

Silica gel column chromatography was used to separate the chemical constituents of CGE A of the root bark of C. angulatus. The characteristic signals of the 1HNMR finger-print were assigned after determining the structures of the compounds isolated from CGE A.

RESULTS

1HNMR finger-prints of the samples of C. angulatus collected from different regions showed highly characteristic features and reproducibility. Three compounds predominant in CGE A were isolated and their structures were determined by spectral analysis as: angulatin A (1), angulatin B (2) and angulatin C (3).

CONCLUSION

Compound 3 is a new compound. Compound 2 was isolated from C. angulatus for the first time. The 1HNMR finger-print of CGE A of the root bark of C. angulatus showed mainly the characteristic signals of the above three compounds and might be utilized for the original authentication of this plant.

[Authentication of traditional Chinese herbal medicines (TCHM) by fingerprints of characteristic general constituents]

OBJECTIVE

To describe the theory, scientific significance, distinguishing features and authentication feasibility of TCHMs by spectral fingerprints of characteristic general constituents.

METHOD

Previous relevant investigations and literatures were summed up in the field, and the present situation on the authentication of TCHMs at home and abroad was analysed.

RESULT

The characteristic general constituents of TCHMs can be obtained by an appropriate procedure. Their compositions and structures can be determined by spectral fingerprints, especially the 1HNMR fingerprint. The species of TCHMs can be identified accurately by these fingerprints. Besides, the quality of TCHMs can be evaluated by the contents of their GCEs.

CONCLUSION

Fingerprint authentication of characteristic general constituents of TCHMs has profound significance for the species identification and quality evaluation of TCHMs.

Chinese bittersweet alkaloid III, a new compound from Celastrus angulatus

A novel skeleton alkaloid named Chinese Bittersweet Alkaloid III from the leaves of C. angulatus was reported. The structure and its stereochemistry were established by IR, ID and 2DNMR (1H-1HCOSY, HMQC, HMBC, NOESY), MS and elemental analysis.

Chronic keratoconjunctivitis associated with congenital dyskeratosis and erythrokeratodermia variablis. Two rare genodermatoses

OBJECTIVE

The purpose of the study was to report the ocular manifestations and immunohistopathologic description of two rare forms of genodermatosis: congenital dyskeratosis (CD) and erythrokeratodermia variabilis (EKV).

DESIGN

Case reports.

PARTICIPANTS

Two patients with CD and EKV presenting with chronic keratoconjunctivitis were studied.

INTERVENTION

Clinical photography to show ocular manifestations and dermatologic findings was performed. Conjunctival biopsy was performed to determine the histopathology and immunohistopathology.

RESULTS

In the patient with EKV, the eyelid skin was dry, erythematous, and thickened. The lid margins showed plugging of some of the Meibomian glands, madarosis, and occasional trichiasis. The epibulbar conjunctiva was injected and had a moderate papillary reaction. Both corneas had pronounced vascularization and stromal scarring. Conjunctival biopsy results disclosed a striking number of degranulating mast cells and moderate numbers of plasma cells. Immunohistopathology showed pronounced immunoglobulin G (IgG)-positive cells in the stroma and immunoglobulin A (IgA) positivity in the epithelium. There was scattered immunoglobulin M (IgM) and moderate C3 and C4 positivity in the stroma. In CD, the patient had keratinized lid margins, entropion formation, trichiasis, cicatrizing conjunctivitis, and symblephra formation. The corneal surface was keratinized, with deep and superficial vascularization. Conjunctival biopsy specimens showed pronounced epithelial keratinization and squamous metaplasia. Degranulating mast cells and eosinophils were prominent in the stroma. Immunohistopathology showed C4 and immunoglobulin D positivity on the keratinized epithelial surface with rare foci of immunoglobulin E-positive cells. Basal epithelial cells were positive for IgA and IgG, and a large number of IgA and IgG plasma cells were present in the substantia propria.

CONCLUSION

To the authors' knowledge, these case reports represent the first clinical description of the ocular manifestation of EKV and the first immunohistopathologic description of the affected conjunctiva in EKV and CD, both of which should be considered in the differential diagnosis of genodermatosis associated with chronic keratoconjunctivitis.

A new murine model of allergic conjunctivitis and effectiveness of nedocromil sodium

BACKGROUND

Allergic conjunctivitis is the most common atopic disease affecting the eye. To study the pathophysiology and effectiveness of antiallergic drugs, it is necessary to develop animal models that closely mimic human allergic conjunctivitis.

OBJECTIVE

The study was performed to develop an experimental murine model of ocular allergic conjunctivitis to an airborne allergen.

METHODS

SWR/J mice were divided into the following groups: group 1, untreated, experimental; group 2, phosphate-buffered saline-treated; group 3, nedocromil sodium-treated; and group 4, unmanipulated controls. Groups 1, 2, and 3 were exposed to ragweed by topical contact with the nasal and conjunctival mucosae. Allergic conjunctivitis was evaluated by scoring of clinical signs, serum IgE levels, and histologic findings.

RESULTS

Mice exposed to ragweed had clinicopathologic signs of allergic conjunctivitis and specific anti-ragweed IgE. Allergic conjunctivitis was modulated by nedocromil sodium. Treated mice had fewer clinical signs of allergy, lower levels of ragweed-specific IgE, reduction of conjunctival eosinophil infiltration, decrease in the number of intact and degranulating mast cells, and reduction of cytokine release.

CONCLUSION

This is the first report of a murine model of allergic conjunctivitis to an airborne allergen that can be used to study the disease pathophysiology and its response to treatment.

[T-cell-induced prevention of HSV-1 keratitis by immunization with the synthetic peptide of glycoprotein D]

C.AL-20 mice susceptible to herpes simplex virus (HSV) were protected against HSV keratitis (HSK) and encephalitis by subcutaneous immunization with synthetic peptide corresponding to the N-terminal amino acid residues 5-23 of HSV glycoprotein D, which is a dominant immunogen of HSV-1. Protection against HSV was related to a potent humoral anti-HSV response. FACScan analysis revealed that CD4+V beta 8(1.2)+ cells in the spleen were markedly decreased 2 days after HSV challenge, and CD8+ cells were increased. Numerous CD4+ and V beta 8(1.2)+ cells were found in the corneal tissue from HSV-infected sham-immunized mice; no such cells were seen in gD(5-23) immunized mice. No cytotoxic cells were detected in the corneas or spleens of gD(5-23) immunized mice, and these mice had decreased DTH responses. Protection against HSV through immunization with gD(5-23) involves humoral and cellular immune mechanisms. CD4+V beta 8(1.2)+ maybe critical in mediating the pathology of HSK. CD8+ cells may be protective by non-cytotoxic mechanisms. Our results suggest that gD peptides may be potent as vaccines against HSV.

Herpes simplex virus type 2 induced retinal necrosis in BALB/c mice

We injected herpes simplex virus type 2 of MS- or G-strain into the anterior chamber of BALB/c mice. In the contralateral eye inflammatory cell infiltration began in the ciliary body; focal retinitis, detected by day 8, led to total destruction of the retina by day 10. Contralateral disease was observed in 75% of mice inoculated with 8 x 10(3) pfu herpes simplex virus type 2, but in only 20% of mice receiving 80 pfu herpes simplex virus type 2. Still this low concentration, however, produced a suppressed delayed-type hypersensitivity response. Anti-herpes simplex virus type 2 antibody, first detected on day 8, reached high titers on day 10; by then, most of the mice had died of encephalitis. The G-strain of herpes simplex virus type 2 was more neurotoxic than the MS-strain, but produced the same incidence of contralateral retinitis. Herpes simplex virus type 2 products contralateral necrotizing retinitis comparable to that produced by herpes simplex virus type 1. These findings, like those of other authors, suggest a role for herpes simplex virus type 2 in some cases of acute retinal necrosis in humans.

Combination preoperative radiation and endocavitary hyperthermia for rectal cancer: long-term results of 44 patients

Long-term results of 122 patients with advanced rectal cancer who were randomly treated with three different methods from July 1984 to July 1986. Of 122 patients, 44 were treated with endocavitary 915 MHz microwave applicators combined with 10 MeV X-ray or 60CO followed by surgery (group A), 38 with preoperative radiation (group B) and 40 with surgery (group C) as a control group. The temperature on the surface of the applicator touching the middle of the caudad to cephaladic extent of disease was 45-50 degrees C for 45 min twice a week for 6-8 sessions. Radiation dose was 30 Gy or 40 Gy/4 weeks. Of cases with stages 0 and A, 45.5% (20/44) were in group A, 23.7% (9/38) in group B and 12.5% (5/40) in group C (chi 2 test p < 0.05 and p < 0.01, respectively). Five-year survival rate was 66.7% (24/36) in group A, 50% (14/28) in group B and 40.5% (15/37) in group C. Percentage of survival at 5 years was 73.7% (14/19) for 40 Gy plus heat, 57.1% (8/14) for 40 Gy alone, 58.8% (10/17) for 30 Gy plus heat, and 42.9% (6/14) for 30 Gy alone. Data suggest a survival advantage for patients treated with preoperative radiation combined with endocavitary hyperthermia.

Topical cyclosporine A and corneal wound healing

The effect of 2% topical cyclosporine A (CsA) ointment on corneal epithelial and stromal wound healing was evaluated in a masked, placebo-controlled study in rabbits. The difference in epithelial would healing rate in the treatment and placebo group was not statistically significant. There was also no difference in the values of bursting strength of 2-mm central penetrating wounds and in the measurement of hydroxyproline content in the central corneal buttons from the wounded area in both the groups. Clinical evaluation of the quality of regenerating epithelium, stromal edema, haze, and iritis did not reveal a difference between the two groups. There was a significantly higher incidence of conjunctival injection in the CsA-treated group. We conclude that topical cyclosporine A 2% does not significantly inhibit epithelial or stromal corneal wound healing.

Depletion of T-lymphocyte subsets in murine herpes-simplex-virus retinitis

Uniocular injection of herpes-simplex virus type 1 into the anterior chamber of BALB/c mice induced contralateral retinitis with relative preservation of the ipsilateral retina. Overall 95% of T-cell deficient nude mice developed ipsi- and contralateral retinitis, suggesting the importance of T-cells in this model. We then depleted lymphocyte subsets in susceptible BALB/c and resistant CB-17 and C57BL/6J mice using anti-CD4 (helper/inducer cells) or anti-CD8 (suppressor/cytotoxic cells) monoclonal antibody. 85% of CD8-depleted, 58% of CD4-depleted and 50% of untreated BALB/c mice developed contralateral retinitis. All CD4- and CD8-depleted animals developed severe ipsilateral retinitis. These results suggest that CD8 cells (but not CD4 cells) are protective for the contralateral retina in BALB/c mice and that both subsets are important for the ipsilateral protection. In CB-17 and C57BL/6J mice, depletion produced no change in the contralateral retina but resulted in ipsilateral retinitis, suggesting different mechanisms for ipsi- and contralateral protection. The possible role of the anterior-chamber-associated immune deviation is discussed.

Diet and cancer of the colon and rectum: a case-control study in China

A case-control study was carried out in Harbin city to assess the role of diet in the aetiology of colorectal cancer. A total of 336 incident cases of histologically confirmed colorectal cancer (111 colon cancer and 225 rectal cancer) and an equal number of controls with other non-neoplastic diseases were interviewed in hospital wards. Data concerning the average frequency of consumption and amount consumed of single food items were obtained by a dietary history questionnaire. Odds ratios and their confidence limits were computed. Multiple regression for risk status was also used. Vegetables, particularly green vegetables, chives and celery, have a strong protective effect against colorectal cancer. Reduced consumption of meat, eggs, bean products and grain was associated with increasing risk for cancer of the rectum. Alcohol intake was found to be an important risk factor for developing colon cancer and male rectal cancer.

[Clinicopathological study of combined preoperative radiotherapy with intracavitary hyperthermia in rectal cancer]

118 specimens of rectal cancer were studied pathologically. 40 cases were treated by both preoperative radiotherapy and intracavitary hyperthermia (group 1), 38 treated by preoperative radiotherapy alone (group 2) and 40 by operation alone (group 3). The tumor disappearance rates by gross observation were 57.5% and 5.3% in groups 1 and 2 (P less than 0.001). The moderate to severe damage of cancer cells (X2-X4) was observed in 90% of cases in group 1 and 31.6% in group 2 (P less than 0.05). In the former, the cancer cell disappearance was observed in 8 cases, while in the latter, only 1 case. The cell degenerations by 30 Gy plus hyperthermia were similar to those by 40 Gy plus hyperthermia, but both were more marked than by 30 Gy alone or 40 Gy alone (P less than 0.05). The lymphocyte, plasma cell infiltration and hyperplasia of fibrous tissue around the tumor in group 1 were more marked than those in groups 2 and 3 (P less than 0.05). The thrombosis around the tumor was more in group 1 than in group 2 (P less than 0.01). Every histological type of the tumor was sensitive to radiotherapy combined with hyperthermia. The lymph node metastatic rates were 35% in group 1 and 31.6% in group 2, both being lower than that in group 3 (52.5%). Immune function of the lymph nodes and the damage of the normal tissues around the tumor are observed. It has been clinically confirmed that neither resection rate is influenced nor postoperative complications are increased by preoperative radiotherapy combined with hyperthermia.

[Extent of lymph node dissection in rectal carcinoma]

Basing on 170 specimens of advanced rectal cancers radically resected, metastatic rule and extent of lymph node dissection were studied in order to guide future surgical treatment. In 170 cases, 77 had lymph node metastases. The lymph node metastatic rate was 45.3% and metastatic degree was 8.9% (527/5 912). Metastasis of the rectal cancer, according to the lymphatic anatomy, can be divided into upward, lateral and downward drain. Because the rectal cancer at any site can lead to the upward metastasis, the upward lymph node dissection, up to the base of inferior mesenteric artery (the third line of lymph nodes), must be done in all rectal cases, otherwise, 10% of patients would have residual cancer. In view of the lateral metastasis occurring only in rectal cancers under the peritoneal reflection, for which lateral lymph node dissection is necessary or one eighth of patients would have residual lesion. Generally, no lateral lymph node dissection is needed in cancers above the peritoneal reflection. Pathologic factor influencing the lymphatic metastasis is the form of tumor growth, such as poorly differentiated and mucoid adenocarcinomas aggressively growing deeply and extensively resulting in a higher lymph node metastatic rate, for which lymph node dissection must be performed.