Nitrotyrosine formation and apoptosis in rat models of ocular injury

This study was performed to examine inducible nitric oxide synthase (NOS-2) expression, nitrotyrosine formation and apoptosis in rats with elevated intraocular pressure (IOP) and/or ocular inflammation. Ocular inflammation was induced via injection of intra-vitreal lipopolysaccharide (LPS) while IOP was elevated by episcleral vessel cauterization. Animals were randomized to one of the following conditions: elevated IOP, LPS, elevated IOP+LPS, and control. Immunohistochemical staining and western blot analysis of retinal lysates revealed NOS-2 and nitrotyrosine immunoreactivity in all disease groups. NOS-2 expression and protein nitration was significantly greater in rats with elevated IOP+LPS compared to elevated IOP, LPS, and control groups. Nitrite levels in the retina affirmed significantly increased levels of nitric oxide generation in LPS-treated rats with elevated IOP (346+/-23.8 microM) vs LPS-treated, elevated IOP and control groups (195.6+/-12.6, 130+/-2.5 and 76.6+/-15.6 microM, respectively). Retinal TUNEL staining showed apoptosis in all diseased groups. Percent of apoptotic cells was significantly greater in the elevated IOP+LPS group compared to LPS-treated or elevated IOP groups. Presented data illustrates that both elevated IOP and ocular inflammation augment NOS-2 expression, retinal protein nitration and apoptosis in rats.

Effect of hypercholesterolemia on inducible nitric oxide synthase expression in a rat model of elevated intraocular pressure

PURPOSE

This study was performed to examine the effect of hypercholesterolemia on inducible nitric oxide synthase (NOS-2) expression and oxidative tissue injury in an experimental rat model of elevated IOP.

METHODS

Wistar rats were maintained on either regular chow or a high-cholesterol diet for 24 weeks. Intraocular pressure (IOP) was elevated in hypercholesterolemic rats by unilaterally cauterizing three episcleral vessels. Rats were divided into four experimental groups as follows; hypercholesterolemia, hypercholesterolemia+elevated IOP, elevated IOP and control. NOS-2 distribution, lipid peroxidation and retinal nerve fiber layer (RNFL) thickness was evaluated in all experimental groups at the end of 24 weeks.

RESULTS

Light microscopic evaluation of retinas in hypercholesterolemic rats revealed breaks and discontinuation in focal areas in the outer nuclear layer (ONL). NOS-2 positive staining was observed throughout the outer plexiform layer (OPL), inner plexiform layer (IPL) and ganglion cell layer (GCL) in rats with elevated IOP and/or hypercholesterolemia. Calculated values of RNFL thickness in hypercholesterolemic rats were significantly higher than those in the control and elevated IOP group. Vitreous malondialdehyde (MDA) levels detected in elevated IOP (3.51+/-0.31 nmol/mg protein) and hypercholesterolemia+elevated IOP (5.14+/-1.28 nmol/mg protein) groups were significantly higher than those detected in hypercholesterolemic (1.92+/-1.43 nmol/mg protein) and control (1.89+/-0.24 nmol/mg protein) groups.

CONCLUSION

The presented data confirms hypercholesterolemia as a risk factor in the development of glaucomatous optic neuropathy (GON) and suggests that increased circulating cholesterol may exacerbate disease progression by inducing NOS-2 expression and elevating oxidant tissue injury.

Impact of chronic renal failure and peritoneal dialysis fluids on advanced glycation end product and iNOS levels in penile tissue: an experimental study

OBJECTIVES

To investigate the impact of chronic renal failure (CRF) on advanced glycation end product and inducible nitric oxide synthase (iNOS) in penile tissue, we examined the advanced glycation end product 5-hydroxy methyl furfural (5-HMF) content and iNOS expression in rats in which uremia had been produced by greater than 85% nephrectomy. In addition, the contribution of peritoneal dialysis (PD) fluids to the elevation of penile tissue 5-HMF levels and iNOS staining scores has been investigated.

METHODS

Adult male Wistar rats, aged between 10 and 12 weeks and weighing 200 to 330 g, were divided into five groups that each included 6 animals. The first group served as a control group. In the second group, CRF was induced and a peritoneal catheter was implanted, but PD was not performed. In group 3, CRF was induced and PD was performed using dialysis fluids containing 1.36% glucose and icodextrin. In group 4, CRF was also induced and PD was performed using 3.86% glucose and icodextrin. Finally, in group 5, without CRF, an indwelling catheter was implanted, and the PD procedure was performed using dialysis fluids containing 3.86% glucose and icodextrin.

RESULTS

The elevation in 5-HMF levels and iNOS staining scores in penile tissue from groups 2, 3, 4, and 5 was significant compared with group 1 (P <0.05). The elevation in 5-HMF levels and iNOS staining scores was also significant between groups 2 and 3, 2 and 4, 3 and 4, 3 and 5, and 4 and 5 (P <0.05). Moreover, the correlation between the 5-HMF levels and iNOS staining scores was statistically significant (r = 0.525, P = 0.003).

CONCLUSIONS

In the present experimental study, we found that 5-HMF levels and iNOS staining scores were significantly elevated in rat penile tissue in which uremia had been produced compared with the groups without CRF. Additionally, PD fluids containing glucose had an effect on the elevation of penile tissue 5-HMF levels and iNOS staining scores.

Epidermodysplasia verruciformis associated with neurofibromatosis type 1: coincidental association or model for understanding the underlying mechanism of the disease?

We describe a 25-year-old man with epidermodysplasia verruciformis (EV) associated with neurofibromatosis type 1 (NF1). The lesions, persisting for more than 15 years, consisted of widespread planar warts on the backs of the hands and wrists, and reddish-brown macules on the trunk, neck and face. During the last 5 years, our patient developed several epithelial tumours, namely solar keratoses, plaques of Bowen's disease and squamous cell carcinomas (SCCs). He also presented with NF1 lesions with neurofibromas, café-au-lait macules, axillary freckling and Lisch nodules. He had left tibial bowing. Polymerase chain reaction analysis of the skin lesions demonstrated the presence of human papillomavirus (HPV) 15 in a flat wart, HPV 20 in a plaque of Bowen's disease, and HPV 15 and HPV 20 in an SCC lesion. Both EV and NF1 show an inherited predisposition to malignancy but the molecular mechanism underlying tumour development is not fully understood. The appearance of both diseases in our patient may be a coincidental association but may also contribute to the identification of loci for susceptibility to NF1 and EV on chromosome 17.

An unusual presentation of immunodeficiency with hyper-IgM

Hyper-IgM syndrome is a rare immunodeficiency disease characterized by markedly decreased serum IgG, IgA, and IgE levels but normal or elevated IgM levels. The most common clinical signs are infections, cirrhosis, arthritis, malignancies, and mucosal ulcers. Approximately two-thirds of patients have chronic neutropenia associated with oral and perirectal ulcers. We report a 14-month-old girl with hyper-IgM syndrome who has recurrent cutaneous ulcers restricted to the diaper area.

A patient with extra-adrenal retroperitoneal paraganglioma and review of the literature

Paragangliomas can arise from virtually any site in the body containing embryonic neural crest tissue. We present a female patient with an extra-adrenal retroperitoneal paraganglioma, and a review of the literature.

Fine needle aspiration biopsy in hepatic Echinococcus multilocularis

OBJECTIVE

To determine the fine needle aspiration biopsy (FNAB) findings in hepatic Echinococcus multilocularis.

STUDY DESIGN

FNAB and tru-cut liver needle biopsy were applied in 14 hepatic E multilocularis cases. Cytologic smears were stained with May-Grünwald-Giemsa and periodic acid-Schiff (PAS) stain. Tissue sections were stained with hematoxylin-eosin (HE) and PAS stain.

RESULTS

In tissue sections, homogeneous, thin, cystic structures of various dimensions strongly stained with PAS. Mucoid material was stained with PAS in the cystic structures. Wide, coagulative necrosis was observed in all cases. In some cases there were foreign body-type giant cells at the periphery of the lesion. In all the cytologic smears there were an intense necrotic ground, PAS-positive hyaline cuticular structures and mucoid globules; in some cases there were foreign body-type giant cells.

CONCLUSION

The above cytologic characteristics are basic diagnostic criteria for FNAB of E multilocularis.

Primary tonsillar tuberculosis: a case report

A 67-year-old man with an enlarged left tonsil underwent a tonsillectomy for the suspicion of malignancy. He had had a dental extraction six months earlier. Clinical and histopathological investigations established the diagnosis of primary tonsillar tuberculosis.