TIMP-2 reduces proteolytic opening of blood-brain barrier by type IV collagenase.

Intracerebral hemorrhage occurs in tumors, stroke and head trauma. Proteolysis of the extracellular matrix around cerebral capillaries by naturally occurring mammalian 72-kDa type IV collagenase may initiate this pathologic event. To investigate this hypothesis adult rats underwent intracerebral injection of type IV collagenase purified from human melanoma cells. Histologically, at 4 h there was perivascular cellular infiltration with hemorrhage, and by 24 h there was infarction with necrosis, edema and hemorrhage. Ultrastructurally, the basal lamina of endothelial cells was disrupted at 2 h. Brain uptake of [14C]dextran and [3H]sucrose increased after intracerebral injection of type IV collagenase compared to controls (P less than 0.0001). Tissue inhibitor of metalloproteinase-2 (TIMP-2) reduced the tracer uptake (P less than 0.02). Metalloproteinase inhibitors reduce extracellular matrix proteolysis and protect the blood-brain barrier.     

Tumor-cell-platelet aggregation does not correlate with metastatic potential of rat 13762NF mammary adenocarcinoma tumor cell clones

The ability of tumor cells to induce platelet aggregation has been correlated with their capacities to colonize the lungs of experimental animals. We tested this hypothesis by studying the ability of cloned, low-passage metastatic tumor cell lines derived from rat 13762NF mammary adenocarcinoma to aggregate rat platelets in vitro and in vivo, and we then compared this activity to metastatic potential by determining the incidence of lung metastasis after subcutaneous or intravenous inoculation of the tumor cell clones into syngeneic rats. Our results failed to show a correlation between in vitro platelet-aggregating activity and metastatic potential. In this system we could not detect platelet-aggregation activity with the most metastatic tumor clone, while the least metastatic clone clearly possessed high platelet-aggregating activity. In addition, by measuring changes in blood platelet and fibrinogen concentrations at various intervals following intravenous injection of tumor cell clones, we were able to confirm in vivo the observed in vitro differences in their plateletaggregating activities. Thus, platelet aggregating activity is heterogeneously expressed among 13762NF cell clones and appears unrelated to spontaneous or experimental metastasis in this tumor system.     

高效液相色谱法测定血浆中洛美沙星浓度及其在人体内药代动力学

建立了人血浆洛美沙星的反相离子对高效液相色谱测定方法。该法简便易行,精密度好,方法回收率95～102%,日内、日间RSD为2.1～7.8%,血药浓度在0.125～5.012 μg/ml范围内呈线性关系,相关系数0.9998,当S/N=2时,最小检测浓度为25 ng/ml。健康志愿者口服400 mg洛美沙星,药代动力学过程符合一室模型,消除相半衰期为5.5 h。     

Occupational risk among orchard workers: a descriptive study

Orchard workers are exposed to an array of occupational health and safety hazards that result in injury, illness, and, in some cases, death. The purpose of this qualitative study was to identify and explore factors that contribute to occupational risks related to orchard work. Twenty-five Hispanic orchard workers were interviewed. They reported that the most common type of accident was falls, usually from a ladder; and the most common injuries were strains and sprains. Three broad categories of factors that contributed to the occurrence of such injuries were Knowledge, Attitudes and Behaviors; Work-Related Factors; and Factors External to Work.     

Difficulties in Immunohaematology : The Weak D Antigen

Background

The Rh blood system is one of the most polymorphic and immunogenic systems known to humans. The expression of Rh blood group antigen is complex. The Rh D antigen is the most important of the antigens that constitute the Rh antigen system. In most cases, D antigen can easily be detected. However, due to variability of expression, weak forms antigen are encountered. The reactivity of weak D with antisera is variable and presents as a problem in blood banking.

Methods

A retrospective analysis for a five-year period was done. Blood samples that were negative for Rh D by immediate spin tube method were tested for weak D antigen by additional lab tests.

Result

Of 34932 serial Rh grouping tests done in our Blood Bank, the incidence of weak D Rh antigen was 0.189%. All these were confirmed by the antiglobulin test.

Conclusion

These patients present as a problem for the blood banker and a curiosity to the clinician. Although uncommon, all health care workers should be aware of this entity to avoid anti D alloimmunisation.Key Words: Weak D, Rh Blood Group     

Cytokeratin CK 7 and CK 20 expression in pituitary adenomas

The pattern of immunohistochemical expression of cytokeratins 7 (CK 7) and 20 (CK 20) is commonly used to assess possible primary sites of metastatic carcinomas. Because pituitary tumors are almost always benign, there has been little interest in their cytokeratin profile. However, we recently reported the use of CK 7/20 expression to document malignant progression and metastasis of a pituitary tumor, indicating the potential diagnostic usefulness of the CK 7/20 profile of pituitary adenomas. We analyzed CK 7/20 expression in 97 pituitary adenomas subclassified by immunohistochemical hormone expression. In about 90% of all subtypes, CK 7 was either negative or reactive in only a few scattered cells. Corticotrophs and sparsely granulated growth hormone-positive adenomas were consistently CK 20 positive (and CK 7 negative) whereas all other subtypes were almost always CK 20 negative. This CK 20-positive, CK 7-negative profile is previously described consistently only in colonic adenocarcinomas. This study documents that subtypes of pituitary adenomas have different CK 7/20 profiles. Whereas this pattern is likely to have diagnostic usefulness in only rare adenomas, the presence of a unique CK signature in corticotrophs and sparsely granulated growth hormone-positive adenomas, subtypes particularly noted for invasive and aggressive behavior, merits further investigation.     

Experience in management of 51 non-functioning pituitary adenomas: indications for post-operative radiotherapy

OBJECT: The indications for additional radiotherapy (RT) after surgery for non-functioning pituitary adenoma are controversial. The goal of this retrospective study was to evaluate the outcome of surgically treated patients, with or without post- operative irradiation. METHODS: Review of cases treated for non-functioning pituitary adenoma. Fifty-one patients were identified, with a mean post-operative follow-up of 6.4+/-3.5 yr. Twenty-nine patients showed residual tumor after surgery and 22 did not. Serial endocrine, visual and radiological evaluations were made after treatment to assess the efficacy and toxicity of surgery and RT. Twenty-seven patients with residual tumor after surgery received RT (22 of them during the post-operative period and 5 after an interval of several yr: 3 because of increased tumor size and 2 with stable residual lesion); tumors in 14 of these patients decreased in size, 11 appeared to be stable on imaging and one patient showed some increase in tumor size (one patient was not followed-up). The residual tumors of the 2 non-irradiated patients remained stable after 5 and 7 yr, respectively. Twenty-two patients without residual disease after surgery (11 with post-operative irradiation, 1 with RT 5 yr after transsphenoidal surgery because of tumor recurrence, and 10 without RT) have shown no evidence of tumor regrowth on serial images. CONCLUSIONS: Radiotherapy can be avoided in patients with complete macroscopic resection and absence of residual tumor in post-operative images; they must be carefully followed using imaging techniques and, in the case of recurrence, they should be re-operated and/or irradiated.