Profiling the dynamic interaction of p300 with proximal promoters of human T cells identified a class of genes that rapidly coassemble p300 and RNA polymerase II (pol II) following mitogen ...stimulation. Several of these p300 targets are immediate early genes, including FOS, implicating a prominent role for p300 in the control of primary genetic responses. The recruitment of p300 and pol II rapidly transitions to the assembly of several elongation factors, including the positive transcriptional elongation factor (P-TEFb), the bromodomain-containing protein (BRD4), and the elongin-like eleven nineteen lysine-rich leukemia protein (ELL). However, transcription at many of these rapidly induced genes is transient, wherein swift departure of P-TEFb, BRD4, and ELL coincides with termination of transcriptional elongation. Unexpectedly, both p300 and pol II remain accumulated or "bookmarked" at the proximal promoter long after transcription has terminated, demarking a clear mechanistic separation between the recruitment and elongation phases of transcription in vivo. The bookmarked pol II is depleted of both serine-2 and serine-5 phosphorylation of its C-terminal domain and remains proximally positioned at the promoter for hours. Surprisingly, these p300/pol II bookmarked genes can be readily reactivated, and elongation factors can be reassembled by subsequent addition of nonmitogenic agents that, alone, have minimal effects on transcription in the absence of prior preconditioning by mitogen stimulation. These findings suggest that p300 is likely to play an important role in biological processes in which transcriptional bookmarking or preconditioning influences cellular growth and development through the dynamic priming of genes for response to rechallenge by secondary stimuli.
Abstract This paper reviews the scientific evidence for the safety of carbon monoxide (CO) and nitric oxide (NO) inhalation to measure pulmonary diffusing capacity (DLCO and DLNO ) in pregnant women ...and their fetuses. In eight earlier studies, 650 pregnant women had DLCO measurements performed at various times during pregnancy, with a minimum of two to four tests per session. Both pregnant subjects that were healthy and those with medical complications were tested. No study reported adverse maternal, fetal, or neonatal outcomes from the CO inhalation in association with measuring DLCO . Eleven pregnant women, chiefly with pulmonary hypertension, and 1105 pre-term neonates, mostly with respiratory failure, were administered various dosages of NO (5–80 ppm for 4 weeks continuously in pregnant women, and 1–20 ppm for 15 min to 3 weeks for the neonates). NO treatment was found to be an effective therapy for pregnant women with pulmonary hypertension. In neonates with respiratory failure and pulmonary hypertension, NO therapy improved oxygenation and survival and has been associated with only minor, transient adverse effects. In conclusion, maternal carboxyhemoglobin (HbCO ) levels can safely increase to 5% per testing session when the dose-exposure limit is 0.3% CO inhalation for ≤3 min, and for NO, 80 ppm for ≤3 min. The risk of late fetal or neonatal death from increased HbCO from diffusion testing is considerably less than the risk of death from all causes reported by the Centers for Disease Control, and is therefore considered “minimal risk”.
The human cytokine, Recombinant Human Regulated on Activation, Normal T Expressed and Secreted (rhRANTES), is a small glycoprotein secreted by activated T cells and platelets and is structurally ...related to a family of chemotactic cytokines called chemokines. Evaluation of the effects of chemokines on human cells has largely been limited to in vitro binding assays. In an effort to study the in vivo effects of chemokines on human leukocyte migration, we examined the ability of rhRANTES to induce human T cell infiltration using a human/severe combined immune deficient (SCID) mouse model. SCID mice received human peripheral blood lymphocytes, followed by sequential subcutaneous injections of rhRANTES in the hind flank for 3 days. The skin and underlying tissue from the rhRANTES injection site were then biopsied and examined for the extent of human mononuclear cell infiltration. rhRANTES induced significant mononuclear cell accumulation 72 h after injection. Immunohistological evaluation determined that the majority of the cells recruited in response to rhRANTES injections were human CD3+ T cells with equal numbers of CD4+ and CD8+ cells. In contrast, subcutaneous injections of recombinant human macrophage colony-stimulating factors resulted in little human cellular infiltration. Murine mononuclear cell infiltration in response to rhRANTES was also present suggesting that the in vivo effects of rhRANTES may be both direct and indirect. These results demonstrate that rhRANTES induces significant human T cell migration in vivo and suggests that the human/SCID mouse model may provide an important tool in studying the in vivo effects of chemokines on human leukocytes and leukocyte subsets.
Tarsal tunnel syndrome Reade, B M; Longo, D C; Keller, M C
Clinics in podiatric medicine and surgery
18, Issue:
3
Journal Article
Peer reviewed
Most authors agree that surgical decompression is the treatment of choice for tarsal tunnel syndrome when conservative treatment fails. Overall, the results of surgical treatment for tarsal tunnel ...have been favorable. Studies have shown that surgical release improves or resolves symptoms of tarsal tunnel syndrome in 85% to 90% of cases.
We sought to determine the effects of long-term hypoxemia on fetal cardiac output and flow distribution.
We exposed six pregnant sheep to high altitude (3820 m) hypoxia from 30 to 135 days' gestation ...(term 146 days). Ten to 14 days after surgery we determined fetal cardiac output and organ blood flows by means of the radiolabeled microsphere technique during a baseline period and also during an additional 30-minute period of more severe added acute hypoxemia.
Baseline maternal arterial PO2 was 60.7 +/- 1.7 torr and fell to 35.1 +/- 3.0 torr during the added acute hypoxemia. Fetal arterial PO2 decreased from 18.5 +/- 1.1 to 11.4 +/- 1.5 torr during added acute hypoxemia. Baseline fetal cardiac output was 351 +/- 55 ml/min/kg, which was significantly lower than previously reported values in low-altitude fetuses. Blood flow to critical organs such as the heart and brain was maintained at levels found in low-altitude fetuses, but flow to the carcass was significantly lower (-49%) than the mean value reported in the literature for low-altitude fetuses. Oxygen delivery was also maintained at normal levels to the brain and heart but was reduced in the kidneys (-31%), gastrointestinal tract (51%), and carcass (-58%). During added acute hypoxemia cardiac output did not change significantly; however, blood flow to the brain, heart, and adrenal glands increased 112%, 135%, and 156% (p < 0.05), respectively.
We conclude that during long-term hypoxemia redistribution of fetal cardiac output is maintained favoring the brain and heart.
Flavone-8-acetic acid plus recombinant human interleukin 2 is a successful antitumor therapy in mice bearing the Renca murine renal cell carcinoma. This report demonstrates that T cells, particularly ...CD8+ T cells, are critical for the generation of this response. Initial experiments examining T-cell signal transduction proteins demonstrated that T cells from Renca-bearing mice had undetectable levels of p56lck and zeta-chain of the T-cell receptor and that flavone-8-acetic acid and recombinant human interleukin 2 therapy could be used as a model for reversal of these alterations. However, further experimentation showed that the majority of the reduction in zeta-chain and part of the reduction in p56lck was due to degradation of these molecules during protein extraction caused by mature granulocytes contaminating the enriched T-cell population. This was not the case for nuclear c-Rel or NF kappa B p65, which remained at undetectable/reduced levels in the absence of granulocytes, confirming our previous data that transcription factor alterations exist in tumor-bearing mice. Thus, most of the reduction in zeta-chain in T cells from Renca-bearing mice is due to granulocyte contamination and emphasizes the need to use pure T-cell populations and/or sufficient amounts and types of protease inhibitors when quantitating proteins in T cells from tumor-bearing mice.
W. J. Pearce, A. D. Hull, D. M. Long and L. D. Longo
Department of Physiology, Loma Linda University School of Medicine, California 92350.
We have examined age-related changes in segments of common ...carotid (Com),
basilar (Bas), posterior communicating (PC), and middle cerebral (MC)
arteries taken from 14 near-term fetal lambs, 62 newborn lambs 3-7 days
old, and 42 adult nonpregnant sheep. Transition from fetal to newborn life
was associated with a decreased water content in all arteries ranging from
0.6% (Com) to 2.3% (Bas), no change in the relative content of cellular
protein, an increase in wall thickness ranging from 4% (MC) to 26% (Com),
an increase in maximum contractile tension ranging from 18% (MC) to 82%
(Com), an increase in stiffness, an increase in the maximum active stress
ranging from 6% (Bas) to 43% (Com), a decrease in the amine-to-potassium
ratio (calculated as the maximum response to 10 microM serotonin with 20
microM histamine divided by the maximum response to 122 mM K+) ranging from
8% (Bas) to 51% (Com), and a decrease in the norepinephrine-to-potassium
ratio ranging from 2.1% (Bas) to 56% (Com). Thus developmental changes
associated with the transition from fetal to newborn life were much more
pronounced in the larger, more proximal Com than in the smaller, more
distal cerebral arteries, suggesting that, at term, the cerebral arteries
are more mature both functionally and structurally than the Com arteries.
Similarly, the transition from newborn to adult life was associated with
much greater changes in Com characteristics than with those of the cerebral
arteries. These studies demonstrate that the effects of aging vary
considerably along the cerebrovascular tree and that conclusions based on
developmental studies of large systemic arteries cannot be freely
extrapolated to the smaller arteries of the circle of Willis.
Although high-dose interleukin-2 (IL-2) can produce durable remissions in a subset of responding patients with renal cell carcinoma (RCC), this occurs in the setting of significant toxicity. The ...purpose of this study is to define the maximum-tolerated dosage (MTD) of IL-2 and interferon alfa-2a (IFN alpha-2a) that can be administered chronically on an outpatient basis.
Fifty-three patients with advanced cancer of variable histology with good prognostic features were treated in six cohorts. Patients in cohorts one through five received IL-2 (1.5 or 3.0 x 10(6) million units (mU)/m2) Monday through Friday and IFN alpha-2a (1.5 or 3 x 10(6) mU/m2) daily for a 4-week cycle. In cohort six, IFN alpha-2a was given three times a week. Immunologic monitoring, including serum levels of soluble IL-2 receptor (sIL-2R) and neopterin, flow cytometry, and natural killer cell (NK) activity, were measured. Patients were evaluated for toxicity, response, and survival.
Almost all patients developed grade I/II toxicities commonly associated with cytokine therapy. Symptoms were most severe with the first treatment of each week. Dose-limiting toxicities included grade III fatigue, hypotension, and creatinine elevations. The MTD was 1.5 mU/m2 daily x 5 given subcutaneously repeated weekly for IL-2 and 1.5 mU/m2 daily subcutaneously (dose level 3) for IFN. Six of 25 assessable patients with RCC (24%) achieved a partial response (PR), including four of eight patients who were previously untreated. There were no objective responses in patients with other tumors, including 12 melanoma patients.
IL-2 and IFN alpha-2a can be given with tolerable toxicities on an outpatient basis and shows significant activity in patients with metastatic RCC.
Center for Perinatal Biology, Department of Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, California 92350
Submitted 19 August 2003
; accepted in final form 7 ...October 2003
We previously demonstrated that cortisol regulated 1 -adrenoceptor-mediated contractions differentially in nonpregnant and pregnant uterine arteries. Given that chronic hypoxia during pregnancy has profound effects on maternal uterine artery reactivity, the present study investigated the effects of chronic hypoxia on cortisol-mediated regulation of uterine artery contractions. Pregnant ( day 30 ) and nonpregnant ewes were divided between normoxic control and chronically hypoxic maintained at high altitude (3,820 m), arterial P O 2 : 60 mmHg for 110 days groups. Uterine arteries were isolated and contractions measured. In hypoxic animals, cortisol (10 ng/ml for 24 h) increased norepinephrine-induced contractions in pregnant, but not in nonpregnant, uterine arteries. The 11 -hydroxysteroid dehydrogenase inhibitor carbenoxolone did not change cortisol effects in nonpregnant uterine arteries, but abolished it in pregnant uterine arteries by increasing norepinephrine pD 2 (log EC 50 ) in control tissues. The dissociation constant of norepinephrine- 1 -adrenoceptors was not changed by cortisol in nonpregnant, but decreased in pregnant uterine arteries. There were no differences in the density of glucocorticoid receptors between normoxic and hypoxic tissues. Cortisol inhibited the norepinephrine-induced increase in Ca 2+ concentrations in nonpregnant arteries, but potentiated it in pregnant arteries. In addition, cortisol attenuated phorbol 12,13-dibutyrate-induced contractions in normoxic nonpregnant and pregnant uterine arteries, but had no effect on the contractions in hypoxic arteries. The results suggest that cortisol differentially regulates 1 -adrenoceptor- and PKC-mediated contractions in uterine arteries. Chronic hypoxia suppresses uterine artery sensitivity to cortisol, which may play an important role in the adaptation of uterine vascular tone and blood flow in response to chronic stress of hypoxia during pregnancy.
pregnancy; norepinephrine; protein kinase C; glucocorticoid receptors; calcium sensitivity
Address for reprint requests and other correspondence: L. Zhang, Center for Perinatal Biology, Dept. of Physiology and Pharmacology, Loma Linda Univ. School of Medicine, Loma Linda, CA 92350 (E-mail: lzhang{at}som.llu.edu ).
Patients with advanced indolent lymphoma often have long survival (median, 4 to 8 years) in spite of frequent relapses. The inability of combination chemotherapy or radiation therapy (RT) to render ...patients disease free has led to radically divergent treatment approaches. Initial treatment may vary from aggressive combined modality therapy to no initial treatment. We sought to evaluate these two divergent approaches in a randomized trial of advanced indolent lymphomas (nodular, poorly differentiated lymphocytic; nodular mixed; diffuse, well-differentiated lymphocytic; diffuse, intermediately differentiated lymphocytic; and diffuse, poorly differentiated lymphocytic). A total of 104 patients were entered: 44 were randomly assigned to "watch and wait" in which only carefully defined, limited RT was administered if necessary; 45 were randomly assigned to aggressive combined modality treatment with prednisone, methotrexate, doxorubicin, cyclophosphamide, plus etoposide plus mechlorethamine, vincristine, procarbazine, prednisone (ProMACE-MOPP), followed by total nodal irradiation (TNI); and 15, with symptoms requiring initial therapy, received the identical combined treatment but were not randomly assigned. Of 41 evaluable patients on watch and wait, 23 (56%) have still not required systemic therapy, although 16 (39%) have received limited RT. Median time to crossover was 34 months. Of 18 patients crossed over, seven of the 16 who completed therapy (43%) achieved CR; two (11%) have relapsed. Histologic progression was seen in six (15%) of 41 patients on watch and wait without intervening chemotherapy. Of 45 patients randomly assigned to chemotherapy, 37 (82%) have completed induction therapy, and 29 of the 37 (78%) achieved CR. Twenty-five of those 29 patients (86%) are still in their first remission. Median duration of initial remission has not been reached but will exceed 4 years.
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