histopathological changes and immunohistochemical findings of acute, chronic nonlupoid and chronic lupoid types of cutaneous leishmaniasis

Dry type localized cutaneous Leishmaniasis due to Leishmania tropica is one of the most prevalent cutaneous parasitic infections in Kerman province. It seems that cellular immune response and the nature of immune inflammatory cells comprising the inflammatory background play a determinant role in this infection. Skin biopsies of 53 patients with acute [<2 years duration], nonlupoid chronic [>/= 2 years duration] and lupoid chronic [new lesions around old scar] types of cutaneous leishmaniasis due to Leishmania tropica were studied by hematoxylin-eosin staining for evaluation of inflammatory cells and epidermal and dermal changes. Immunohistochemical staining was used to determine immunophenotypic patterns [CD1a, CD68, CD3, CD8, CD4, CD20] and to evaluate host immune response at tissue level, the correlation between the presence and concentration of certain cell types, and the clinical presentation and duration of disease. Mean percentages of epidermal and dermal Langerhans cells CD1a+ were higher in lupoid than in acute lesions. Also, the predominant T lymphocyte in acute, chronic and lupoid leishmaniasis was T CD8+. It seems that Langerhans cells CD1a+ are responsible for the suppression of the inflammatory response against L.tropica infection and by providing Leishmania antigens in a steady state induce tolerance to the Leishmania antigens and consequently cause cutaneous chronic lupoid leishmaniasis. This study also suggests that T CD8+ play an effective role in parasite elimination and in the process of healing of cutaneous leishmaniasis due to Leishmania tropica

[Gabapentin effect on visceral pain and its interaction with antinociceptive effect of morphine in mice]

Visceral pain is one of the most common forms of pain which requires new therapeutical drugs. The aim of this study is to investigate the inhibitory effect of gabapentin on induced abdominal contractions and to examine the effect of its co- administration with morphine. In this study, 96 mice received acetic-acid intraperitoneally after administration of saline, gabapentin [1, 5, 10, 50 and 100 mg/ kg], morphine [0.25, 0.5, 1, 3 and 5 m/g kg] or a combination of subanalgesic dose of morphine with subanalgesic and the lowest effective dose of gabapentin. In one group naloxone [5mg/kg/i.p] was injected 20 minutes prior to the injection of acetic acid. Then the number of writhes were counted for 45 minutes. Both gabapentin and morphine reduced writhing in a dose-dependent manner. The number of writhes decreased significantly by gabapentin [50 and 100/ mg/kg] and morphine [0.5, 1, 3, 5 mg/kg] comparing to the control group [P<0.001]. Also, the sub-analgesic dose of morphine [0.25mg/kg] with sub-analgesic and low effective dose of gabapentin [50mg/kg and 10mg/kg, respectively] significantly decreased the number of writhes [P<0.005]. The combination of low effective dose of gabapentin [50mg/kg] and sub-analgesic dose of morphine decreased the number of writhings by 94% as compared to the controls [P<0.005]. The antinociceptive effect of combinational administration was not reversed by naloxone [opioid antagonist]. These data demonstrated the comparable efficacy of gabapentin [50 and 100/ mg/ kg; i.p.] with 0.5mg/kg morphine in visceral pains. Also the combination of subanalgesic doses of gabapentin and morphine, which were ineffective alone, produced significant analgesic effect in writhing model of pain. Therefore, combination of low doses of morphine and gabapentin, due to lower rate of side effects, may be clinically considered as a safer treatment in the management of visceral pains

[Evaluation of the effect of gabapentin in the enhances of the analgesic response to morphine in tail flick of male rats]

Opioids, as drug of choice in acute pain treatment, have many side effects including dependency. Therefore, the combinational therapy of other drugs accompanied with opioids could decrease the side effects, tolerance and opioid dependency. In this study the effect of gabapentin and morphine co-administration was evaluated in acute model of pain. In this experimental study, the antinociceptive effect of gabapentin [30 or 90mg/kg, s.c.] and morphine [0.5, 1 and 3mg/kg, s.c.] alone or in combination with gabapentin were measured by Tail-flick test every 15 minuxtes up to 105 mins in intact adult male rats. Control rats received normal saline. Area Under Curve [AUC], as antinociceptive index, was calculated for each groups. Both gabapentin [90mg/kg] and morphine [1 and 3mg/kg] showed antinociceptive response as compared to controls [p<0.05]. But there was not any significant differences between the [AUC] of 0.5mg/kg morphine and 30mg/kg gabapentin as compared to controls, so these doses were considered as subanalgesic doses. The co-administration of subanalgesic doses of morphine [0.5mg/kg] and gabapentin [30mg/kg] increased significantly AUC as compared to morphine alone [p<0.001]. The co-administration of gabapentin [30 and 90mg/kg] with analgesic doses of 1mg/kg [p<0.005] and 3mg/kg morphine also increased significantly AUC antinociceptive index as compared to controls [p<0.05]. Gabapentin enhanced the antinociceptive effects of both analgesic and subanalgesic doses of morphine in a dose dependent manner in acute pain model in male rats

[Effects of morphine dependency on bone healing in rat]

Bone fractures usually happen during car accident and sport trauma. Deferent factors influence bone healing such as malnutrition and smoking. Apart from addiction, which is an important individual, social and cultural problems morphine has several effects on body physiology and immune system .This study is performed to assess the effect of morphine dependency on bone healing and has not been reported in the literature until now. 56 rats were divided into two 28-rat groups and were kept under equal laboratory conditions, Rats of the control group were not addicted by adding morphine powder to the water of the other group for 21 days, and they got addicted and were used as case group. Following intraperitoneal naloxone injection and confirming addiction in addicted group a hole was made in tibia of both groups. Biopsies were taken on the 3rd, 6th, 10th and 20th day from 7 addicted and 7 non-addicted rats. Then the results of microscopic examination were statistically analyzed with Mann-Whitney test. The deference between neutrophilic exudates [P=0.002] and granulation tissue [P=0.003] on the 3rd day, percent of neutrophilic exudates [P=0.01] and immature bone [p=0.004] on the 6th day the percent of immature [P=0.00I] and mature bone [P=0.02] on the 10th day and mesenchymal tissue [P=0.02] on the 2dh day was significant It was concluded that bone healing was delayed in the addicted group