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Objective: The aim of this study was to identify the participation of the coagulation system in the differential diagnosis of pleural effusions., Introduction: Imbalance between immunologic and metabolic factors triggers a sequence of events resulting in pleural reactions and accumulation of fluid. The coagulation system, which is fundamental for the maintenance of homeostasis, contributes to the inflammatory process responsible for pleural effusions, and participates in cellular proliferation and migration as well as in the synthesis of inflammatory mediators., Methods: We evaluated the laboratory profile of coagulation and fibrinolysis in 54 pleural fluids (15 transudates and 39 exudates)., Results: The coagulation system acts according to the pathophysiologic mechanisms involved in the development of pleural effusions. In inflammatory effusions (exudates), there is activation of coagulation with increased levels of fragment 1+2 and thrombin-antithrombin complex in addition to reduction of fibrinogen levels due to fibrinolysis and fibrin tissue incorporation. As a consequence, there is activation of the fibrinolytic system with increased levels of fibrin degradation products, including the D-dimer. These changes are not sufficient for differentiation of different subgroups of exudates. In transudates, these events were observed to a lesser degree., Conclusion: The coagulation system plays an important role in the development of pleural diseases. Coagulation tests show differences between transudates and exudates but not among exudate subgroups. Understanding the physiopathological mechanisms of pleural disorders may help to define new diagnostic and therapeutic approaches.

The effects of isolated estrogen therapy on the hemostatic system and arterial distensibility were determined in postmenopausal females with type 2 diabetes mellitus. This was a prospective nonrandomized study of 19 subjects (age, 56.2 +/- 4.7 years; body mass index, 27.8 +/- 2.4 kg/m(2) [mean +/- SD]). Inclusion was done after 2 months of glycemic and blood pressure control. The study consisted of 4 months of placebo treatment immediately followed by an equal period of oral conjugated equine estrogens (CEE) 0.625 mg/d. Measures included anthropometrics, a metabolic profile (oral glucose tolerance test and fasting glycated hemoglobin, total cholesterol and fractions, and triglyceride levels), and coagulation and fibrinolytic factors at the end of the placebo period and after 4 months of oral CEE. Conjugated equine estrogen therapy decreased plasminogen activator inhibitor 1 (placebo x CEE: 16.33 +/- 9.11 x 13.08 +/- 8.87 UI/mL, P < .03) and increased factor VIII activity (134.11% +/- 46.18% x 145.33% +/- 42.04%, P < .04). An increase in high-density lipoprotein cholesterol levels (placebo x CEE: 42.47 +/- 6.80 x 53.32 +/- 11.89 mg/dL, P < .01), and a decrease in glycated hemoglobin (8.45% +/- 1.30% vs 7.58% +/- 1.06%, P < .02) and in fasting glucose levels (121.51 +/- 21.05 x 111.21 +/- 20.74 mg/dL, P = .02) followed CEE therapy. Pulse wave velocity and augmentation index were performed by applanation tonometry and were obtained at the end of the placebo period (placebo), again after an intravenous load of 1.25 mg of CEE (short-term), and after 4 months of oral CEE (long-term). A significant decrease in central (carotid-femoral) pulse wave velocity was seen both after short- and long-term CEE (placebo vs short-term vs long-term: 9.36 +/- 2.58 vs 8.26 +/- 2.20 vs 7.98 +/- 1.90 m/s, respectively [analysis of variance, P < .03]; placebo vs short-term, P < .05; placebo vs long-term, P < .01), whereas augmentation index decreased only after long-term CEE (placebo vs short-term vs long-term: 39.14% +/- 6.94% vs 37.48% +/- 8.67% vs 34.3.3% +/- 8.11% [analysis of variance, P < .05], respectively; placebo vs long-term, P < .05). Long-term administration of CEE leads to an improvement in fibrinolysis and arterial distensibility, associated with an increase of the intrinsic coagulation pathway in postmenopausal women with type 2 diabetes mellitus.

Tissue processing methods using methacrylate and epoxy resins, which were developed for transmission electron microscopy, allow histopathologic study of specimens by light microscopy with a degree of resolution unavailable with wax methods. We have routinely used epoxy resins in the study of specimens of diseased liver; this is, to our knowledge, the first reported study of such a procedure. Use of epoxy resins allows optimal tissue preservation and maximum use of the resolving power of the light microscope, and the use of polychromatic stains obviates the need for routine use of special stains. We believe that reexamination of specimens of diseased liver using high-resolution light microscopy will provide additional morphologic information for a better understanding of the pathology of liver and more accurate morphologic diagnosis.

Seven hundred renal specimens embedded in epoxy resins and stained with polychromatic stains were compared with paraffin sections stained with Hematoxylin and Eosin (H & E), Perodic and Schiff, (PAS), silver, and trichrome stains. High resolution of light microscopy, never in wax histopathology, may be obtained by the use of plastic embedding and polychromatic stains. Cell boundaries, intracellular organelles, basement membranes, different cellular types, apposition of different substances, and other pathologic changes were readily recognized in a single P + P (Plastic section stained with Polychromatic stains) section, whereas paraffin sections usually needed special stains. The same plastic block may be used for transmission electron microscopy. Slightly elevated cost, special training of the technician and pathologist, and some few remaining technical difficulties are the disadvantages of this method. High resolution light microscopy methods are recommended for routine renal biopsies.

Routine serial sections for light microscopy (LM) from one sample and transmission electron microscopy (TEM) from selected areas of another sample are current procedures in renal pathology. At the present time, there are methods available to perform high-resolution light microscopy (HRLM) and TEM from the same block. However, this technology is not directly applicable or convenient for routine renal biopsies. Most methods presently available to obtain TEM studies from different areas of the same large HRLM block use reembedding methods, which considerably delay TEM studies, or mesa technics that fragment and waste the original block. Present methods to obtain serial sections from plastic blocks have been used in plant and animal morphology and need to be modified for renal pathology. In the present article, the authors present a technic that produces immediate TEM sections from different areas of the same HRLM block. This method does not produce fragmentation or waste of the original block, and TEM sections are obtained within two hours after large HRLM sections are screened. The latter sections are mounted serially on a regular microscopic slide on 8-15 separate wells painted with water-repellent ink. The methods are simple and produce large HRLM and TEM sections in 24 hours, avoiding separate samples for LM and TEM studies.