Neuronal injury after photoactivation of photofrin II.

Photodynamic therapy has been used in the management of patients with malignant brain tumors even though the effects of this form of treatment on the adjacent normal brain are incompletely characterized. The authors examined, in sequential experiments, morphologic alterations affecting the cerebral cortex in rats injected with Photophrin II and exposed to light. Initially, minimal cell alterations, including cisternal swelling of both endoplasmic reticulum and Golgi apparatus, involved only neurons located in the superficial layers of the cerebral cortex exposed to light. These changes spread, over a period of several hours, from the surface to the bottom of the cortex and eventually involved the entire cortical segment exposed to light. The earliest structural signs of lethal injury to neurons developed over a period of 18 hours after porphyrins had been photoactivated and astrocytes had been severely damaged. Signs of lethal injury to neurons included an increase in the number of mitochondrial cristae and appearance of amorphous electron-dense deposits within swollen mitochondria. The appearance of these alterations was followed by segregation of intracytoplasmic organelles and fragmentation of nuclear and cytoplasmic membranes. The tissue changes, including those involving neurons, eventually progressed to coagulation necrosis at 48 hours. These observations suggest that prophyrins injected to rats (48 hours before photoactivation) cause swelling and necrosis of astrocytes. This is followed by neuronal necrosis, which appears at two time intervals; the initial neuronal necrosis occurs after the astrocytic disintegration. A second type of neuronal alteration appears after microvessels become thrombosed and ischemia is likely to develop.     

Insulin, chemotherapy, and the mechanisms of malignancy: the design and the demise of cancer

The endogenous molecular biology of cancer cells involves autocrine and paracrine secretion of insulin and insulin-like growth-factors I and II, which subserve energy production and growth stimulation, respectively, in these cells. These activities confer on cancer its malignant potential, working as they do autonomously, free from higher levels of integrated control. Taking advantage of cancer's mechanisms of malignancy by employing exogenous insulin as a biologic response modifier, it is possible to potentiate the cytotoxic effects of chemotherapeutic agents for improved treatment of cancer. A synergy between certain membrane and metabolic effects of insulin on cancer cell molecular biology increases anticancer drug efficacy, and it does so with reduced doses of the drugs, enhancing their safety. This treatment strategy has been applied abroad over the last five decades with very promising clinical results.     

Totally implantable venous access ports: frequency of complications and analysis of bacterial contamination after ablation

Totally implantable venous access ports (TIVAP) are valuable medical devices for long-term intravenous treatment such as parenteral nutrition, cancer chemotherapy or antiviral therapy. Implantation and use of these devices are each associated with infectious or mechanical complications. AIMS OF THE STUDY: To determine the frequency of complications and to analyze bacterial contamination of different parts of TIVAP (tip, septum, internal lumen of the port). MATERIAL AND METHODS: Clinical charts of patients, which TIVAP was removed between April 20th to December 31st 2003, were retrospectively reviewed. Infectious complications (local and septicemic) and non-infectious complications (i.e. obstruction, thrombosis, drug extravasation...) were defined using clinical and/or microbiological criteria. Quantitative culture from different parts of the TIVAP was performed. RESULTS: One hundred and ten patients (age 57 +/- 14-years-old, 94.3% cancers) were included, corresponding to 57,018 catheter-days: 39.1% had one or more non-infectious complications (density incidence: 0.86 for 1000 catheter-days). Among the 49 complications, obstruction, thrombosis, extravasations and malposition accounted for 30.6%, 30.6% 4.1% and 6% of cases. Twenty-one patients (19.1%) had an infectious complication: 11 were local and 14 were systemic (density incidence 0.43 for 1000 catheter-days). Bacteria responsible for TIVAP-associated bacteraemia were coagulase negative staphylococci (N = 2), Staphylococcus aureus susceptible to methicilline (N = 3), micrococci (N = 1), corynebacteria (N = 1) or Gram-negative bacilli (N = 8). Comparison of quantitative culture of the different parts of TIVAP with a threshold at 10(3) CFU/ml showed that culture of tip, septum and port has a sensitivity of 47.6% 57.1% and 61.9 %, respectively and a specificity of 100% 92.1% and 92.1%, respectively for the diagnosis of TIVAP infection. CONCLUSION: Complications associated to TIVAP are frequent but incidence that we have reported is comparable with previous studies. Analysis of internal lumen of the port is the most sensitive method for the diagnosis of TIVAP-associated infections.     

Allotypes in Basilea rabbits

Basilea rabbits produce immunoglobulin molecules, practically all of which have lambda light chains rather than kappa chains. This variant strain was derived form a homozygous (b9/b9) male. Sensitive serological methods revealed that at least some homozygous bas/bas individuals possess traces (about 100 ng/ml) of b9 molecules. This level usually increases to almost 1 microgram/ml upon hyperimmunization with pneumococcal or streptococcal vaccines. One exceptional rabbit, with 50 micrograms/ml of b9 molecules, was found. In spite of the presence of b9 molecules in early pre-immune bleeds, homozygous bas/bas rabbits produce strong anti-b9 antibodies; i.e., they are capable of making autoantibodies. These anti-b9 allotypic antisera were not distinguishable by our methods from routinely produced anti-b9.     

Quantitation of IgE on the basophil surface in atopic patient

A radioimmunoassay was employed in order to quantitate IgE on the basophil surface in 6 normal and 10 pollen sensitive subjects. A basophil-rich fraction obtained from whole blood in a Ficoll gradient was incubated with specific anti-IgE; the inhibition produced by surface IgE was standard inhibition curve. Atopic patients had on the average about 10-30 times as many IgE molecules per basophil as control subjects. Total and specific IgE as well as degranulation by Lollium perenne crude extract were also studied in both populations and their results compared with those of basophil IgE quantitation.     

Fine-needle aspiration diagnosis of Kaposi's sarcoma in a developing country

Fine-needle aspiration (FNA) cytology was performed on 15 patients with peripheral lymphadenopathy and/or skin lesions referred to the Department of Pathology of the Hospital Central of Maputo, Maputo, Mozambique. Epitrochlear lymph nodes were the most frequently aspirated site. All aspirates allowed diagnoses of Kaposi's sarcoma (KS). Smears contained loosely cohesive clusters of bland spindle cells, with a radial arrangement and nuclear crush artifacts. These diagnostic clues have not been described in other spindle-cell intranodal lesions that should be considered in differential diagnoses. Taking into consideration the high prevalence of AIDS and limited resources for diagnosis in Africa, FNA cytology appears to be a useful method for the diagnosis of KS in developing countries, reducing the necessity for surgical lymph node excision.     

Therapy of malignant supratentorial neuroepithelial tumors

Hopes raised by results published by Leibel and Sheline in "Journal of Neurosurgery" 66 (1987) 1-22 have not been confirmed in our own work. Nevertheless, even our own results, though not statistically significant, have shown a combination of surgery, irradiation, and polychemotherapy to be recommendable for treatment of cases of malignant supratentorial glioma.     

一氧化氮对谷氨酸单钠脑损害小鼠学习记忆能力的影响

目的　观察谷氨酸单钠 (MSG)对小鼠学习记忆的影响及血浆、脑内NO含量的变化。方法　给断乳分窝小鼠MSG灌胃 ,每天 2次 ,连续 30d ,31d早灌胃后对小鼠进行迷宫行为训练 ,2 4h后对其进行迷宫记忆检测 ,用硝酸还原酶法检测血浆脑内的NO含量。结果　MSG对小鼠学习记忆能力有影响并存在剂量效应关系 ,其血浆、脑中NO含量均升高并有显著差异 (P <0 .0 5 )。结论　NO可加重MSG对小鼠学习与记忆的损害作用。     

Donor Choriocarcinoma Transmission From Solid Organ Transplantation: A Case Report

Transplantation of any organ has some inherent risk of disease transmission, such as infection and malignancy. The present study aims to describe 2 cases of choriocarcinoma transmission after kidney and liver transplantation originating from the same patient. The donor was a 17-year-old woman who died of cerebral hemorrhage. Both organ recipients died of metastatic choriocarcinoma few months after the transplantation, within days after starting chemotherapy. Retrospective hCG (human chorionic gonadotropin hormone) analysis in donor's blood stored at the time of donation had a result of 9324 mIU/mL. Despite its rarity, clinicians should be aware of the risk of transplant-related choriocarcinoma from female donors in childbearing age. In some cases, hCG dosage should be performed before donation.