Effects of gemcitabine on cisplatin-induced nephrotoxicity in rats: schedule-dependent study.

The effects of gemcitabine (dFdC) on the lipid peroxidation and kidney histopathology in the nephrotoxicity of an antitumour drug cisplatin (CDDP) were studied in rats. dFdC was administered intraperitoneally (i.p.) at single doses of 90 mgkg(-1) while CDDP was administered i.p. at single doses of 6 mgkg(-1). Both drugs were injected either alone or sequentially in combination. In one case, CDDP preceded dFdC by 4 h and 24 h and in the other case, dFdC preceded CDDP by 4 h and 24 h. Seven days after CDDP administration, the nephrotoxicity was manifested biochemically by elevation of serum creatinine, blood urea nitrogen and an increase in the kidney weight as a percentage of total body weight. In addition, marked decreases in serum albumin and calcium levels were observed. Lipid peroxidation in the kidney was monitored by measuring the malondialdehyde (MDA) production level and kidney glutathione (GSH) content, which were increased and depleted, respectively. Administration of dFdC 4 h and 24 h after CDDP administration did not significantly change the indices of CDDP-induced nephrotoxicity or the kidney platinum concentration levels in comparison with those animals treated with CDDP alone. On the contrary, administration of dFdC 4 h and 24 h prior to CDDP administration significantly aggravated CDDP-induced nephrotoxicity which was manifested by severe increases in the serum creatinine and blood urea nitrogen levels as well as kidney weight as a percentage of total body weight. In addition, kidney tissue showed severe GSH depletion and increases in the MDA production and platinum concentration levels. Moreover, treatment of rats with dFdC 24 h prior to CDDP resulted in much more aggravation of CDDP-induced nephrotoxicity in comparison with those animals treated with dFdC 4 h prior to CDDP. Histopathological examination demonstrated tubular atrophy, tubular necrosis and drug-induced nuclear changes in the CDDP-treated group. However, pretreatment of rats with dFdC 4 h and 24 h prior to CDDP revealed extensive interstitial nephritis, renal tubular atrophy and tubular necrosis with 'sloughing off' of the lining cells, especially with those rats treated with dFdC 24 h prior to CDDP. These results might suggest that administration of dFdC prior to CDDP enhanced the lipid peroxidation in kidney tissue and aggravated CDDP-induced nephrotoxicity.     

Propionic acidemia and zinc deficiency presenting as necrolytic migratory erythema

Necrolytic migratory erythema was first described in 1942 in a patient with pancreatic islet cell carcinoma. The disease can, however, have other etiologies including nutritional dermatoses. Here, we describe the clinicopathological picture of a 7-year-old female patient who presented with necrolytic migratory erythema which we believe is secondary to a rare combination of zinc deficiency and propionic acidemia.     

Interdigitating dendritic cell tumor

Interdigitating dendritic cell tumor is an extremely rare neoplasm that mainly occurs in lymph nodes. In this case report, we describe the histopathological and clinical features of a typical interdigitating dendritic cell case in a 30-year-old Saudi female who presented with a painless unilateral left neck mass. Microscopically, the lesional tissue in the affected lymph node showed whorls and fascicles of spindle cells intermingling with small lymphocytes. The neoplastic cells were strongly and diffusely positive for S-100 protein, vimentin and alpha 1-antichemotrypsin and focally for macrophages marker (CD68). The combined morphological features and immunohistochemical results were diagnostic of interdigitating dendritic cell tumor.     

Invasive mucormycosis in benign gastric ulcer

Fungal elements are frequently noted overlying the base of chronic peptic ulcers of the stomach and it has been suggested that the fungi enhance the degree of necrosis and that these cases have protracted disease and deeper ulcers with more perforations. It has also been postulated that the number of fungal elements might be increased in the stomach of patients who are receiving potent medications such as H2-receptor antagonists to reduce gastric acidity, but there have not been adequate control studies, and the deleterious effects from the presence of the fungi in these cases have not been substantiated. We present a very rare case of invasive mucormycosis (phycomycosis) occurring in the base of a chronic gastric ulcer in a 55 years old diabetic male. This case was clinically and radiologically been mistaken for a gastric carcinoma. In addition, the ulcer was complicated by perforation and fungal septicemia with subsequent fatal outcome. The clinical, radiological and histopathological features are described together with a literature review of other reported fungal gastric ulcers.     

Systemic Lupus erythematosus and amyloidosis

Summary Amyloidosis in association with Systemic Lupus Erythematosus (SLE) has rarely been reported. We report a patient with "SLE" and Amyloidosis presenting with recurrent bloody diarrhea and review the relevant literature.     

Inhibition of nitric oxide synthase aggravates cisplatin-induced nephrotoxicity: effect of 2-amino-4-methylpyridine

BACKGROUND: Nitric oxide (NO) has been shown to play a role in maintaining normal renal function. However, the role of NO in cisplatin (CDDP)-induced nephrotoxicity is still unclear. The aim of the present work was to examine the effect of the NO synthase (NOS) inhibitor, 2-amino-4-methylpyridine, on the severity of CDDP-induced nephrotoxicity. METHODS: Male Wistar rats were divided into six groups. Three control groups received plain drinking water or water containing 1.5% L-arginine. One of the two groups receiving plain water was treated with an intraperitoneal injection of 2-amino-4-methylpyridine (1 mg/kg in normal saline), and the other two control groups were injected intraperitoneally with normal saline. Another three groups were treated in the same manner and injected with CDDP (6 mg/kg, i.p.). CDDP was injected 1 h after 2-amino-4-methylpyridine treatment. Rats were sacrificed 7 days after CDDP treatment, and serum as well as kidneys were isolated and analysed. RESULTS: CDDP-treated rats showed increases in the kidney weight as a percentage of the total body weight and serum creatinine and urea levels and decreases in serum albumin and calcium levels. Also, CDDP treatment induced reductions in the kidney total nitrate/nitrite (NO(x)), reduced glutathione (GSH) and glutathione peroxidase activity (GSH-Px) levels and an increase in the kidney malondialdehyde (MDA) production level. In contrast, 2-amino-4-methylpyridine treatment 1 h prior to CDDP injection induced marked exacerbation of CDDP-induced nephrotoxicity, as manifested by severe aggravation of the indices of nephrotoxicity. Also, 2-amino-4-methylpyridine plus CDDP-treated rats showed exaggeration of the reduction in the kidney total NO(x) content and GSH-Px activity and elevation of the kidney platinum accumulation level with normalization of the kidney MDA production level and rebound in the kidney GSH content. Histopathologically, CDDP-treated rats showed marked interstitial nephritis, tubular atrophy and tubular necrosis. However, treatment with 2-amino-4-methylpyridine 1 h prior to CDDP injection revealed marked exacerbation of CDDP-induced histopathological changes. CONCLUSIONS: The present findings suggest that NO plays a role in CDDP-induced nephrotoxicity. Administration of 2-amino-4-methylpyridine, an NOS inhibitor, exacerbates CDDP-induced nephrotoxicity.     

Colorectal spirochetosis

Colorectal spirochetosis is a very rare pathologic condition that was been described several decades ago; however, its clinical significance is debatable in causing problems to human beings. We describe the first 2 documented cases of colorectal sprirochetosis in Saudi Arabia and discuss the different views about this entity and it's clinical significance.