Synergy between anti-endoglin (CD105) monoclonal antibodies and TGF-beta in suppression of growth of human endothelial cells

Endoglin (CD105) is a proliferation-associated cell membrane antigen of endothelial cells and strongly expressed in the angiogenic vasculature of solid tumors. Endoglin is essential for angiogenesis/vascular development and an ancillary transforming growth factor beta (TGF-beta) receptor. Certain anti-endoglin monoclonal antibodies (mAbs), termed SN6 series mAbs, inhibited angiogenesis, tumor growth and metastasis in mice. We investigated the mechanisms by which anti-endoglin mAbs suppress growth of proliferating endothelial cells. We found that 4 SN6 series mAbs suppressed growth of human umbilical vein endothelial cells (HUVECs) in a dose-dependent manner in the absence of any effector cells or complement. Significant differences in the growth suppression between the 4 anti-endoglin mAbs defining different epitopes were observed. These differences were not determined by antigen-binding avidities of the mAbs. Combination of TGF-beta1 and each of the 4 anti-endoglin mAbs exerted synergistic growth suppression of HUVECs. Binding of anti-endoglin mAbs to endoglin-expressing cells did not block the subsequent binding of TGF-beta1. Conversely, preincubation of HUVECs with TGF-beta1 did not change cell surface expression of endoglin. The present results suggest that direct suppression of the endothelial cell growth by SN6 series mAbs is one of the underlying mechanisms by which anti-endoglin mAbs exert antiangiogenic and tumor-suppressive activity in vivo. The results further suggest that TGF-beta1 plays an important role in the in vivo antiangiogenic efficacy of anti-endoglin mAbs by synergistically enhancing the activity of these mAbs. Further studies of the present novel findings may provide valuable information about the functional roles of endoglin and anti-endoglin mAbs in the TGF-beta-mediated cell regulation.     

Second malignancies after chemotherapy and radiotherapy for Hodgkin disease

The purpose of this preliminary study was to determine the incidence of second malignancies after combined-modality therapy for adults with Hodgkin disease and relate it to the details of initial treatment. We retrospectively studied 286 patients ranging in age from 16 to 88 years with stage I or II Hodgkin disease who were treated between 1980 and 1995 with chemotherapy followed 3 to 4 weeks later by radiotherapy. Patients received a median of three cycles of induction chemotherapy. Mitoxantrone, vincristine, vinblastine, and prednisone was used in 161 cases, mechlorethamine, vincristine, procarbazine, and prednisone (MOPP) in 67 cases, Adriamycin, bleomycin, vinblastine, and dacarbazine in 19 cases, lomustine, vinblastine, procarbazine, and prednisone/doxorubicin, bleomycin, dacarbazine, and lomustine in 18 cases, and other chemotherapeutic regimens in the remaining 21 cases. The median radiotherapy dose was 40 Gy given in 20 daily 2-Gy fractions. Median follow-up of surviving patients was 7.4 years. There were 2,230 person-years of observation. Significantly increased relative risks (RR) were observed for acute myeloid leukemia (RR, 69.3; 95% CI, 14.3-202.6) and melanoma (RR, 7.3; 95% CI, 1.5-21.3). The 5-, 10-, and 15-year actuarial risks of acute myeloid leukemia were 0.8%, 1.3%, and 1.3%, respectively. Patients treated with MOPP had the highest 15-year actuarial risk of leukemia (1.6%). The 5-, 10-, and 15-year actuarial risks of solid tumors were 1.9%, 9.3%, and 16.8%, respectively. Consolidative radiotherapy to both sides of the diaphragm resulted in a trend toward an increased risk of solid tumors relative to radiotherapy to only one side of the diaphragm (p = 0.08). In an effort to reduce the risk of second malignancies, we have stopped using the alkylating agents nitrogen mustard and procarbazine and elective paraaortic and splenic radiotherapy after chemotherapy.     

Fos expression after mating in noradrenergic cells of the A1 and A2 areas of the medulla is altered by adrenalectomy

In the female rat, the integrity of the ventral noradrenergic bundle (VNAB) is necessary to carry stimuli from the uterine cervix and vagina to brain areas involved in mating-induced pseudopregnancy. Because adrenal hormones are known to alter noradrenergic function, we examined whether adrenalectomy altered mating-induced Fos expression in the A1 and A2 noradrenergic cell groups that project through the VNAB. Ovariectomized females were adrenalectomized (ADX) or sham-operated (Sham) and, 2 weeks after surgery, were given oestrogen and progesterone and mated. They received 15 intromissions, five intromissions or 15 mounts-without-intromission (mounts-only) from a male. Two hours after mating, rats were perfused and brains were collected; controls were perfused after being taken directly from their home cage. After immunocytochemical staining, Fos-immunoreactive (Fos-IR) and dopamine-beta-hydroxylase-immunoreactive (DBH-IR) cells and the percentage of DBH cells that were labelled with Fos (% DBH/Fos) were counted. In the A1 area, Fos-IR and percentage DBH/Fos were not affected by adrenalectomy. Although an overall effect of mating treatment was found for both measures, no specific mating treatment increased labelled cells above home cage levels. In the caudal, middle and rostral A2, 15 intromissions induced a significant increase in Fos-IR in Sham females above all other groups and a higher percentage of DBH/Fos in the middle and rostral A2 areas. ADX females showed no rise in either Fos-IR or percentage DBH/Fos after 15 intromissions. However, in the middle and rostral A2, ADX females showed significantly increased Fos-IR and percentage DBH/Fos after mounts-only treatment above Sham mounts-only females and all other ADX groups. These results demonstrate that adrenal hormones suppress activation of A2 cells to mounts-only stimuli but contribute to A2 activation in response to intromissions from males. The latter effect may result from stress associated with receipt of vaginocervical stimulation during mating.     

Vestibular imbalance associated with a lesion in the nucleus prepositus hypoglossi area

BACKGROUND: The nucleus prepositus hypoglossi (NPH) is known to be a neural integrator of horizontal eye movements. Although the role of the human NPH is not well known, it may also function in postural balance, in view of its anatomic connections with the vestibular nuclei and vestibulocerebellum and of lesion studies in experimental animals. OBJECTIVE: To show that the human NPH contributes to vestibular function in addition to eye movement control. DESIGN: Case series. SETTING: University hospital.Patients Six patients with small and discrete brainstem infarctions that predominantly involved the NPH region.Main Outcome Measure Findings on magnetic resonance images. RESULTS: The NPH was affected at the lower pontine level in 2 patients and at the upper medullary level in 4. In addition to gaze-evoked nystagmus, all patients had vertigo, vomiting, and postural ataxia, suggesting vestibular dysfunction. The patients typically fell contralaterally or bilaterally to the lesion side. CONCLUSION: The NPH serves a vestibular function in addition to its oculomotor control function.     

Metronidazole-induced encephalopathy

We report the clinical, neuropsychological, and neuroimaging findings of two patients of diffuse encephalopathy associated with the use of metronidazole. Both patients showed characteristic abnormalities on magnetic resonance imaging (MRI) with diffusion weighted imaging (DWI) and recovered incompletely after the discontinuation of metronidazole. We also suggest that MRI with DWI may be useful in the diagnosis of metronidazole-induced encephalopathy, and that they have a role in the prediction of prognosis.     

Changes in microcystin production by Microcystis aeruginosa exposed to phytoplanktivorous and omnivorous fish

With direct exposure to phytoplanktivorous fish (Hypophthalmichthys molitrix), increased mass-specific microcystin production occurred in three monoclonal Microcystis aeruginosa strains (NIES 44, 88 and 99). Total mass-specific microcystin content of NIES 44 exposed to H. molitrix was over 50 times higher than controls (a mean value of 16.2 microgg(-1)-dry cell in controls versus 878.6 microgg(-1)-dry cell in treatments). Up to nine times higher microcystin levels were detected in NIES 88 exposed to H. molitrix compared to controls (a mean value of 553 in controls versus 5145 microgg(-1)-dry cell in treatments). The microcystin levels of all strains were significantly different between controls and H. molitrix treatments (P < 0.01 for NIES 44 and 88; P < 0.05 for NIES 99). The microcystin response to the omnivorous Carassius gibelio langsdorfi was weaker than that of H. molitrix, though the levels in all strains exposed to the fish were higher than in controls and a significant difference in microcystin production between controls and omnivorous fish treatments occurred for NIES 44 (a mean value of 6.9 in controls versus 41.5 microgg(-1)-dry cell in treatments; P < 0.01) and NIES 88 (a mean value of 359.8 versus 480.4 microgg(-1)-dry cell; P < 0.05). Microcystis cells were observed in the both fish faeces and gut contents, and microcystin was also detected in the body tissues (from 0.6 to 2.5 microgg(-1)-dry weight) and faeces of both fish species on the final day of experiment, although 98% of fish in three strains of Microcystis cultures had lost weight (mean +/- S.E. fish growth rate with M. aeruginosa; -0.90 +/- 0.06% per day, n = 96). This study showed that several M. aeruginosa strains increased toxin production when exposed to fish, especially phytoplanktivorous species, even though fish appeared not to feed vigorously on toxic Microcystis, and supports the hypothesis that this response is a fish-induced defence mediated by physical contact associated with feeding or by chemical cues (e.g. kairomones).     

Signal transduction of the protective effect of insulin like growth factor-1 on adriamycin-lnduced apoptosis in cardiac muscle cells

To determine whether Insulin-like growth factor (IGF-I) treatment represents a potential means of enhancing the survival of cardiac muscle cells from adriamycin (ADR)-induced cell death, the present study examined the ability of IGF-I to prevent cell death. The study was performed utilising the embryonic, rat, cardiac muscle cell line, H9C2. Incubating cardiac muscle cells in the presence of adriamycin increased cell death, as determined by MTT assay and annexin V-positive cell number. The addition of 100 ng/mL IGF-I, in the presence of adriamycin, decreased apoptosis. The effect of IGF-I on phosphorylation of PI, a substrate of phosphatidylinositol 3-kinase (PI 3-kinase) or protein kinase B (AKT), was also examined in H9C2 cardiac muscle cells. IGF-I increased the phosphorylation of ERK 1 and 2 and PKC zeta kinase. The use of inhibitors of PI 3-kinase (LY 294002), in the cell death assay, demonstrated partial abrogation of the protective effect of IGF-I. The MEK1 inhibitor-PD098059 and the PKC inhibitor-chelerythrine exhibited no effect on IGF-1-induced cell protection. In the regulatory subunit of PI3K-p85- dominant, negative plasmid-transfected cells, the IGF-1-induced protective effect was reversed. This data demonstrates that IGF-I protects cardiac muscle cells from ADR-induced cell death. Although IGF-I activates several signaling pathways that contribute to its protective effect in other cell types, only activation of PI 3-kinase contributes to this effect in H9C2 cardiac muscle cells.     

Phytochemical constituents from<Emphasis Type="Italic">diodia teres</Emphasis>

All ten compounds were isolated from the methanolic extract of the whole plants of Diodia teres through repeated silica gel and Sephadex LH-20 column chromatography. Their chemical structures were elucidated as three iridoid glycosides, asperuloside, geniposidic acid and asperulosidic acid, a coumarin glycoside, scopolin, and six flavonoids, rutin, kaempferol-3-O-rutinoside, quercitrin, astragalin, isoquercitrin and quercetin by spectroscopic analysis.