The rostral level of origin of sympathetic neurons in the chick embryo,studied in tissue culture

Groups of three consecutive somites from the first to the eleventh somite from chick embryos of stages 17–18 were grown in tissue culture for seven days. Sympathetic neurons, identified both by phase contrast microscopy and FIF histochemistry, occurred only in cultures which included the sixth, or more caudal, somites. If it is assumed that sympathetic precursor cells (neural crest cells) have not undergone a caudal shift prior to stages 17–18, and taking into account the loss of one or two rostral somites, then the anterior sympathetic ganglia are derived from neural crest caudal to the sixth or seventh somite Thus, the vagal zone (level with somites 1–7) contributes little to the sympathetic nervous system.     

The effect of flutamide on expression of androgen and estrogen receptors in the gubernaculum and surrounding structures during testicular descent

Background/Purpose

Inguinoscrotal testicular descent is controlled by androgens between embryonic days E16-19, but androgen receptor (AR) and estrogen receptor (ER) locations are unknown. We aimed to find AR, ERα, and ERβ in the gubernaculum and inguinal fat pad (IFP) in normal rats and after flutamide treatment.

Methods

Sprague-Dawley timed-mated rats were injected with flutamide (75 mg/kg body weight/5% ethanol + oil) on E16-19 or vehicle alone. Male fetuses or pups (5-10/group) were collected at E16; E19; and postnatal (P) days 0, 2, 4, 8. Sections were prepared for hematoxylin and eosin or immunohistochemistry for AR, ERα, and ERβ. Receptor labeling was quantitated as distinct nuclear labeling/100 μm² in gubernaculum and IFP.

Results

There was minimal gubernacular AR-labeling until E19, dramatically increasing postnatally. By contrast, at E16-E19 there was significant IFP AR immunoreactivity suppressed by flutamide (P < .05). No ERα expression was observed, but ERβ was expressed in both gubernaculum and IFP, maximally at E16, but unchanged by flutamide.

Conclusions

During the androgen sensitivity window (E16-19), the gubernaculum contains ERβ but minimal ERα or AR, while the IFP, which is supplied by the genitofemoral nerve, contains abundant AR that are flutamide-sensitive. These results suggest that the IFP could be the site of androgenic action controlling gubernacular development.     

Protein C, an antithrombotic protein, is reduced in hospitalized patients with intravascular coagulation

Activated protein C is a potent anticoagulant and profibrinolytic enzyme that can be derived from the vitamin-K-dependent serine protease zymogen, protein C, by the action of thrombin. Protein C antigen concentration was determined in plasmas from normals (n = 40) and from 38 patients with intravascular coagulation as evidenced by positive FDP (greater than micrograms/ml). Plasma protein C was 4 micrograms/ml in normals and was significantly depressed (less than 2 SD below the mean of normals) in 19 of the 38 patients. Of 15 patients with suspected intravascular coagulation but normal FDP, protein C was decreased in 5 individuals; 3 of these 5 patients had liver disease. Based on these results, we suggest that extensive activation of the coagulation system in vivo causes a significant consumption of protein C, presumably due to its activation by thrombin and subsequent clearance.     

Immunohistochemical localization of membrane and alpha-granule proteins in human megakaryocytes: application to plastic-embedded bone marrow biopsy specimens

Using a new technique for antigen localization, we have demonstrated platelet proteins in megakaryocytes in plastic-embedded biopsy specimens of normal human bone marrow. In a series of 25 specimens, megakaryocytes showed labeling with antibodies to the integral membrane glycoproteins IIIa, IIb, and the IIb-IIIa complex; granule membrane protein 140; and five alpha-granule matrix proteins: thrombospondin, factor VIII-related antigen, beta-thromboglobulin, platelet factor 4, and fibrinogen. The antibodies to the membrane glycoproteins IIIa, IIb, and IIb-IIIa produced diffuse cytoplasmic staining and heavier staining on the plasma membrane, whereas the antibodies to the alpha-granule matrix proteins produced a distinct granular staining within the cytoplasm. Staining for granule membrane protein 140 was also granular in distribution. Rare mononuclear cells consistent with megakaryocyte precursors were labeled with these markers. Other enzyme histochemical and lectin-binding studies showed that the enzyme alpha-naphthyl acetate esterase, the lectin Ulex europaeus I, and the periodic-acid Schiff reaction were consistent, but not specific, markers of megakaryocytes. This immunohistochemical technique should facilitate the examination of qualitative and quantitative changes in megakaryocytes in a variety of physiologic and pathologic processes.     

Nylon-fiber-induced neutrophil fragmentation

We have investigated the effects of mechanical elution of neutrophils from nylon-wool fiber (NWF) using the scanning electron microscope and biochemical analysis of elution fractions. We have determined that mechanical removal of neutrophils from nylon-wool fiber disrupts neutrophils adherent to nylon-wool fiber and augments release of granules, release of peripheral cytoplasmic fragments, and release of lactic dehydrogenase, a soluble cytoplasmic enzyme. Mechanical shearing of the adherent cell, and not adherence per se, causes the fragmentation. The extent of fragmentation is proportional to the NWF surface area available to neutrophils and is maximal at the temperature for optimal adherence and spreading. Agents that decrease cell spreading (n-ethylmaleimide and cold) diminish fragmentation. Cytochalasin B, an agent that destabilizes the neutrophil cortex, increases fragmentation. Fragmentation may be an important contributing cause of the abnormal morphology, function, and in vivo survival of nylon-wool-fiber procured human neutrophils. The prevention of fragmentation would appear to be necessary to insure the procurement of optimally functioning cells. Elution of NWF-adherent neutrophils in the cold might be a practical way to diminish neutrophil damage during clinical filtration leukapheresis.