Expression of wound healing and stress-related proteins in keratoconus corneas

PURPOSE: Keratoconus is characterized by thinning and scarring of the central portion of the cornea. This study was performed on keratoconus corneas to examine the expression of proteins related to wound healing including vimentin, an intermediate filament protein, and tenascin, and extracellular matrix protein. The expression of stress-related cytokines, heat shock proteins and ubiquitin was also investigated. METHODS: Corneal buttons were collected from patients with keratoconus, normal subjects and patients with other corneal diseases such as pseudophakic bullous keratopathy. Immunofluorescence staining was performed on frozen sections for vimentin and tenascin, and immunoperoxidase staining was carried out on paraffin sections for cytokines, heat shock proteins and ubiquitin. RESULTS: To varying degrees, all proteins examined, except tenascin and heat shock protein 90, were found to be expressed in normal human corneas. The expression of vimentin, tenascin, transforming growth factor-beta, interleukin-1, heat shock protein 27, and ubiquitin was enhanced in keratoconus corneas. A similar enhancement however was also observed in other diseased corneas. CONCLUSIONS: Altered expression of several wound healing or stress-related proteins was noted in keratoconus corneas. The alterations appear to be nonspecific injury or wound responses in association with corneal diseases.     

Structural basis of the Tanford transition of bovine beta-lactoglobulin

The structures of the trigonal crystal form of bovine beta-lactoglobulin variant A at pH 6.2, 7.1, and 8.2 have been determined by X-ray diffraction methods at a resolution of 2.56, 2. 24, and 2.49 A, respectively. The corresponding values for R (Rfree) are 0.192 (0.240), 0.234 (0.279), and 0.232 (0.277). The C and N termini as well as two disulfide bonds are clearly defined in these models. The glutamate side chain of residue 89 is buried at pH 6.2 and becomes exposed at pH 7.1 and 8.2. This conformational change, involving the loop 85-90, provides a structural basis for a variety of pH-dependent chemical, physical, and spectroscopic phenomena, collectively known as the Tanford transition.     

Analysis of a dual-receiver node with high fault tolerance forultrafast OTDM packet-switched shuffle networks

In this paper, we present a high-performance dual-receiver transparent optical node configuration suitable for two-connected multihop transparent optical networks operating at ultrafast bit rates. The steady-state behavior of optical shuffle networks is analyzed with this configuration and a minimum-loss node configuration. Deflection routing is employed as the means for contention resolution. Both analytical results and simulation results are presented on the network performance in terms of network throughput and delay. We also propose modified routing schemes for network fault tolerance. Applying both store-and-forward and deflection routing techniques, the networks can operate without packet loss in the presence of faults     

Preliminary evidence for an association of Epstein-Barr virus with pre-ulcerative oral lesions in patients with recurrent aphthous ulcers or Beh?et's disease

In this study we used the polymerase chain reaction (PCR), slot blot and Southern blot hybridization, direct sequencing and in situ hybridization (ISH) to show the possible presence of EBV-DNA in pre-ulcerative oral aphthous lesions of patients with recurrent aphthous ulcers (RAU) or Beh?et's disease (BD). For this purpose, formalin-fixed biopsy specimens were obtained from 13 pre-ulcerative oral aphthous lesions of nine RAU and four BD patients. Five specimens of normal oral mucosa (NOM) from five normal control subjects and 10 specimens of oral erosive or ulcerative lesions from 10 patients with erosive lichen planus (ELP) were also included. EBV-DNA was detected by PCR in 5 of the 13 (38.5%) pre-ulcerative oral aphthous lesions, two from RAU patients and three from BD patients. However, no EBV-DNA was demonstrated in five NOM specimens from normal control subjects and in 10 specimens of oral lesions from ELP patients. EBV-DNA was also demonstrated in patients' peripheral blood lymphocytes and/or plasma, suggesting that the lymphocytes may be the reservoir of latent EBV infection and there is EBV shedding in the plasma. EBV-DNA was detected by ISH in only one PCR-positive case; the reaction product was found to deposit on the nuclei of some of the epithelial cells and lymphocytes. By immunohistochemistry, expression of Epstein-Barr nuclear antigen and EBV/C3d receptors was also noted in some of the epithelial cells and lymphocytes in this ISH-positive case. Therefore, we suggest that the epithelial cells of pre-ulcerative oral aphthous lesions may be infected by EBV through EBV-infected lymphocytes; also, the cytotoxic T lymphocyte-induced lysis of the EBV-infected epithelial cells, but not the virus-induced cytolysis, may be the main mechanism causing oral ulcer formation. Our data provide preliminary evidence for an association of EBV with pre-ulcerative oral aphthous lesions in RAU and BD patients.     

Facioscapulohumeral muscular dystrophy (FSHD)

Facioscapulohumeral muscular dystrophy (FSHD; MIM 158900) is one of the major forms of muscular dystrophy, and is inherited in an autosomal dominant fashion. In most patients with FSHD, deletion of 3.3 kb tandemly repeated units within the EcoRI fragment, as detected by p13E-11 (D4F104S1) on chromosome 4q35, is associated with the disease (FSHD1A or 4q35-FSHD). Rare (< 5%) 4q35-unlinked FSHD (FSHD1B) is also known, and therefore genetic heterogeneity exists among FSHD. Recent studies based on the distinction of 4q35 EcoRI fragments from those of 10q26 improved the reliability of molecular diagnosis of the disease (> 95% accuracy). However, gene for FSHD1A has not been identified yet. Identification of the FSHD gene and characterization of the gene product are waited on tiptoe with expectation.     

Heterogeneity of human platelet density subpopulations in aggregation, secretion of ATP, and cytosolic-free calcium concentration

AIM: To investigate thrombin (500 U.L-1)-, ADP (0.1-30 mumol.L-1)-, and 5-hydroxytryptamine (5-HT, 3 mumol.L-1)-induced aggregation, secretion of ATP and cytosolic-free calcium mobilization in density subpopulations of human washed platelets. METHODS: Using Percoll discontinuous gradient. RESULTS: The human platelets were separated into high density (HD), intermediate density (ID), and low density (LD) subpopulations, and their sizes were diminished with decreasing density (r = 0.978, P < 0.01). The magnitude of aggregations by thrombin, ADP, and 5-HT was more significant in HD platelets than that in LD platelets (P < 0.01). The amount of secretion of ATP induced by thrombin and ADP in HD platelets was also much higher than that in LD platelets (P < 0.01), except for 5-HT which did not cause the ensuring release reaction in any subpopulation of human platelets. Thrombin (1500 U.L-1)-, ADP (mumol.L-1)-, and 5-HT (3 mumol.L-1)-induced cytosolic-free calcium mobilization was evaluated as well. Results showed that the resting level of cytosolic-free calcium concentration ([Ca2+]i) was the same in all subpopulations, about 80-90 nmol.L-1. However, the level of [Ca2+]i mobilization was entirely different, heightened with increasing density. CONCLUSION: The function of HD platelets was much stronger and more active than that of LD platelets in human.     

Inhibition of phospholipase C gamma 1 activity by amentoflavone isolated from Selaginella tamariscina

A case of watershed infarction in the spinal cord is reported. The patient underwent bronchial artery embolization for control of massive hemoptysis. The bronchial arteriogram was carefully examined and focused on blood supply to the spinal cord prior to embolization. Acute paraparesis followed the embolization procedure even though there was no visible spinal supply on the arteriogram. Magnetic resonance imaging showed a hyperintensity lesion over the watershed region which is located at the central portion of the upper thoracic cord. This case is reported to emphasize the significant role which angiographically invisible small vessels can play in the blood supply to the spinal cord. The vascular system of the spinal cord and the prevention of spinal cord ischemia secondary to embolization are further discussed here.