Monocyte and granulocyte-mediated tumor cell destruction. A role for the hydrogen peroxide-myeloperoxidase-chloride system.

Human monocytes stimulated with phorbol myristate acetate were able to destroy a T lymphoblast cell target (CEM). Stimulated human granulocytes were also capable of mediating CEM cytotoxicity to a comparable degree as the monocyte. CEM destruction was dependent on the pH and the effector cell number. Both monocyte or granulocyte mediated cytotoxicity were inhibited by the addition of catalase, whereas superoxide dismutase had no inhibitory effect. In addition, CEM were protected from cytolysis by the effector cells by the myeloperoxidase inhibitors, azide and cyanide, or by performing the experiment under halide-free conditions. Glucose oxidase, an enzyme system capable of generating hydrogen peroxide, did not mediate CEM cytotoxicity, while the addition of purified myeloperoxidase dramatically enhanced cytolysis. Hypochlorous acid scavengers prevented CEM destruction by the glucose oxidase-myeloperoxidase-chloride system but neither hydroxyl radical nor singlet oxygen scavengers had any protective effect. These hypochlorous acid scavengers were also successful in inhibiting monocyte or granulocyte-mediated CEM cytotoxicity. Based on these observations we propose that human monocytes or granulocytes can utilize the hydrogen peroxide-myeloperoxidase-chloride system to generate hypochlorous acid or species of similar reactivity as a potential mediator of CEM destruction.     

Does allopurinol reduce pain of chronic pancreatitis?

Summary Conclusion A dosage of 300 mg/d of allopurinol was not effective in reducing pain or improving activities of daily living in chronic pancreatitis. Background Allopurinol prevents the generation of oxygen-derived free radicals by inhibiting xanthine oxidase. The purpose of this study was to determine whether allopurinol is effective in reducing pain of chronic pancreatitis. Methods Thirteen patients with chronic pancreatitis who were experiencing abdominal pain requiring medication at least three times each week entered a randomized, double-blind, two-period crossover clinical trial. Patients evaluated their pain daily using a categorical pain intensity scale, numeric pain intensity scale, and a visual analog scale, and weekly completed a McGill Pain Questionnaire and activities of daily living (ADL) questionnaire. Results The mean baseline score of pain was approx 50% of most severe pain in all scoring systems. There was no significant decrease in pain associated with allopurinol compared to the placebo (p=0.24–0.75). In addition, there was no benefit in terms of ADL score associated with allopurinol compared with placebo (p=0.32). Mean uric acid level was decreased by 1.15 mg/dL while patients were taking allopurinol, compared to when they were taking placebo (p=0.007).     

CASE REPORT: Pancreatic Ascites in an Infant: Lack of Symptoms and Normal Amylase

A 4-month-old boy presented with 9 days of abdominal distension. The abdomen was tense, distended, and nontender, with a fluid wave. Hypoalbuminemia, hyponatremia, high lipase, normal amylase, high ascitic fluid: lipase, amylase, and serum-ascites albumin gradient < 1.1 were present. Abdominal CT showed large ascites, edema, and pancreatic cyst. No improvement was noted with bowel rest, TPN, albumin, furosemide, octreotide, and paracentesis. Endoscopic retrograde cholangiopancreatography showed disrupted pancreatic duct and a cyst. Pancreatic duct stenting was complicated by early outward migration of the stent and was thus ineffective. An exploratory laporatomy revealed a cyst. Cystogastrostomy resolved the pancreatitis and ascites. The patient was discharged off TPN and tolerating enteral nutrition. Pancreatic ascites is rare, producing few or no symptoms in infants. In conclusion, our patient may have had viral pancreatitis, complicated by a disrupted duct and/or ruptured pseudocyst with ascites formation. Medical management was ineffective. Surgery appears to have been curative.     

Pancreas Divisum

Opinion statement  

The Kheda malaria project: the case for environmental control

The Kheda project experience has shown that bio-environmentalcontrol of malaria is feasible, cost effective and ecologicallysound. It clearly brings out the need to consider health issuesat the planning stage of all developments. Bio-environmentalcontrol of malaria is suggested as the first line of attackfor the control of mosquitoes, malaria and other mosquito-bornediseases. Insecticides may be reserved for short-term use. Thiswill enable judicious and selective use of insecticides in solelyepidemic situations. The growing problem of resistance to insecticidesin mosquitoes as well as environmental pollution, can then besolved on a long term basis.     

The effect of the NMDA receptor antagonist MK-801 on cerebral blood flow and infarct volume in experimental focal stroke

The non-competitive N-methyl-D-aspartate receptor/channel antagonist dizocilipine maleate (MK-801) has been reported to reduce infarct volume in a variety of focal stroke models. We examined the effect of MK-801 on infarct volume and cerebral blood flow in temporary and permanent focal ischemia in rats. In Wistar rats exposed to permanent right common carotid artery and 2 h of transient right middle cerebral and left common carotid artery occlusion followed by 22 h of reperfusion, MK-801 reduced infarct volume by 73% (P less than 0.05) and significantly increased cerebral blood flow to the ischemic core throughout the 2-h period of ischemia. In spontaneously hypertensive rats (SHRs) exposed to permanent right common carotid artery occlusion and 2 h of transient right middle cerebral artery occlusion followed by 22 h of reperfusion, MK-801 decreased infarct volume by 13% (P greater than 0.05) and increased cerebral blood flow to the penumbral region. In SHRs subjected to permanent right common carotid and middle cerebral artery occlusion MK-801 reduced infarct volume by 18% at 3 h (P greater than 0.05), by 25% at 6 h (P less than 0.01) and by 18% at 24 h (P less than 0.05). MK-801-treated SHRs had no difference in cerebral blood flow to the ischemic core, but increased cerebral blood flow to penumbral zones as compared with untreated SHRs. These results suggest that the protective effect of MK-801, at least in part, relates to improved cerebral blood flow.     

Extracranial Plasma Cell Granuloma Presenting as a Diffuse Meningeal and lntraparenchymal Mass

Plasma cell granuloma (PCG) is uncommon, characterized by polyclonal proliferation of mature plasma cells, usually within systemic organs. Only four previous cases have involved the central nervous system (CNS). This is the first reported case of an extracranial PCG and secondary involvement of the brain and meninges. Magnetic resonance imaging (MRI) disclosed a diffuse, enhancing meningeal process infiltrating the underlying brain, causing severe swelling and edema, consistent with an inflammatory, infectious, or neoplastic etiology. Examination of temporal dural biopsy specimen demonstrated PCG, consistent with the patient's original tumor. Following dexamethasone and radiation therapy, MRI and neurological findings normalized.     

皮下静脉的红外成像

研究背景和目的 　　在急诊救治的过程中最重要的就是快速建立静脉通道,以补充体液、给药以及输血等.但是,由于皮下结构(如血管深度、脂肪组织、皮肤色素、血管内血容量)的复杂性,往往阻碍了肉眼下静脉穿刺过程的实施.血管超声可以辅助寻找相对较粗的静脉,但是此设备和技术的要求较高,影响了其在临床的广泛应用;可见光透射法所得结果不甚可靠,且容易造成灼伤.红外成像时由于其穿透深度较可见光深,而且血液对红外光能量的吸收明显高于脂肪和黑色素等血管周围组织,因而可以得到对比度清晰的图像.……     

Lymphokine-activated killer (LAK) activity to cultured rat kidney parenchymal components in vitro

Abstract. The susceptibility of cultured rat kidney parenchymal components to natural killer (NK) cell and lymphokine-activated killer (LAK) cell-mediated lysis in a 4-h in vitro ⁵¹chromium assay was investigated. Large granular lymphocytes (LGL) in the spleen and in the kidney allograft were able to lyse YAC cells during rejection, but they did not damage target endothelial, glomerular mesangial, glomerular epithelial, or tubular cells in resting state. Stimulation of the target cells with gamma-interferon - known to induce MHC (class II) antigens on the target cell surface - did not make the target cells susceptible to NK-mediated lysis. LAK cells generated by a 3-day incubation with interleukin-2 (IL-2) effectively lysed both YAC and P815 target cell lines. LAK cells were also slightly cytotoxic to all tested parenchymal target components in resting state. Gamma-interferon treatment of the cultured parenchymal cells prior to the chromium release assay, however, reduced LAK-mediated parenchymal cell cytotoxicity to nearly nondetectable levels. Obviously, many lymphokines, including IL-2 and gamma-interferon, are produced during rejection at the site of inflammation. This might induce the generation of LAK cells in situ as the lymphokines induce the production of MHC antigens in the graft. We interpret these findings as indicating that regardless of the generation of LAK, the protective effect of gamma-interferon neutralizes the LAK effect, and we suggest that neither LGL nor LAK cells play any essential role in rat kidney allograft rejection.