c-Myb and its target Bmi1 are required for p190BCR/ABL leukemogenesis in mouse and human cells

Expression of c-Myb is required for normal hematopoiesis and for proliferation of myeloid leukemia blasts and a subset of T cell leukemia but its role in B-cell leukemogenesis is unknown.

We tested the role of c-Myb in p190^BCR/ABL-dependent B-cell leukemia in mice transplanted with p190^BCR/ABL-transduced marrow cells with a c-Myb allele (Myb^f/d) and in double transgenic p190^BCR/ABL/Myb^w/d mice. In both models, loss of a c-Myb allele caused a less aggressive B-cell leukemia.

In p190^BCR/ABL expressing human B-cell leukemia lines, knockdown of c-Myb expression suppressed proliferation and colony formation.

Compared to c-Myb^w/f cells, expression of Bmi1, a regulator of stem cell proliferation and maintenance, was decreased in pre-B cells from Myb^w/d p190^BCR/ABL transgenic mice. Ectopic expression of a mutant c-Myb or Bmi1 enhanced the proliferation and colony formation of Myb^w/d p190^BCR/ABL B-cells; by contrast, Bmi1 downregulation inhibited colony formation of p190^BCR/ABL-expressing murine B cells and human B-cell leukemia lines. Moreover, c-Myb interacted with a segment of the human Bmi1 promoter and enhanced its activity.

In blasts from nineteen Ph¹ adult ALL patients, levels of c-Myb and Bmi1 showed a positive correlation. Together, these findings support the existence of a c-Myb-Bmi1 transcription regulatory pathway required for p190^BCR/ABL leukemogenesis.

High-intensity focused ultrasound for prostate cancer: a systematic review

High-intensity focused ultrasound (HIFU) has recently been promoted as a non-invasive treatment option for prostate cancer. This systematic review sought to evaluate the evidence comparing it with standard treatment in patients with localised prostate cancer. The literature review included searches of MEDLINE, EMBASE, the Cochrane Library, annual meetings' abstracts and websites of evidence-based practice guideline producers. Studies were included if they were randomised controlled trials comparing HIFU with current management approaches, or were meta-analyses, systematic reviews or practice guidelines addressing HIFU. No randomised controlled trials or meta-analyses were identified. Seven systematic reviews and two practice guidelines were identified; neither contained randomised controlled trials. Adjusting the selection criteria to include case series found 34 clinical studies of HIFU. Twenty-nine evaluated HIFU as the primary treatment and five examined HIFU as salvage treatment for recurrence after radiotherapy. In most studies the outcomes used to determine efficacy were negative biopsy rates or prostate-specific antigen (PSA) levels. Among the 29 studies of HIFU as the primary treatment, negative biopsy rates ranged from 35 to 95% in 21 studies, a PSA nadir of ≤0.5 ng/ml ranged from 55 to 91% in 10 studies and mean PSA nadirs ranged from 0 to 1.9 ng/ml in 17 studies. Five studies reported 5-year disease-free survival rates ranging from 55 to 95%. Among five studies of HIFU as salvage treatment, negative biopsy rates ranged from 73 to 84% in four studies, a PSA nadir of ≤0.5 ng/ml ranged from 57 to 66% in three studies and mean PSA nadirs were 1.97 and 2.38 ng/ml in two studies, respectively. Current evidence on HIFU use in prostate cancer patients is of low quality, rendering it difficult to draw conclusions about its efficacy. Until results from case series are confirmed in prospective studies, the widespread use of HIFU is not supported.

Expression and localization of an aquaporin-1 homologue in the avian kidney and lower intestinal tract

In birds, the kidneys and lower intestine function in osmoregulation. A 271-amino acid homologue to aquaporin-1 (AQP-1) was isolated from the kidneys, cecae, proximal and distal rectum, and coprodeum of the lower intestine in the house sparrow (Passer domesticus). This protein has six transmembrane domains connected by two cytoplasmic loops and three extracellular loops. It exhibits 94%, 88%, and 78% homology to AQP-1 sequences of chicken, human and toad, respectively. Many of the highly conserved amino acids that are characteristic of AQP-1 are found in the sparrow sequence. RT-PCR was performed and the presence of AQP-1 mRNA was detected in the kidney and all four regions of the lower intestine. Immunoblots of total protein identified a 28-kDa non-glycosylated AQP-1 band and a 56-kDa glycosylated AQP-1 band in the kidney and all four regions of the lower intestine. Immunohistochemistry demonstrated the presence of the AQP-1 protein within both the renal cortex and medulla. In the lower intestine, the protein was present in the proximal rectum, distal rectum, and in the coprodeum. As AQP-1 functions to allow water movement across mammalian cell membranes, its presence in water-permeable cells in a bird suggests it may have a similar function.

Maximal androgen blockade for the treatment of metastatic prostate cancer--a systematic review

INTRODUCTION

Maximal androgen blockade (MAB) versus castration alone in patients with metastatic prostate cancer has been extensively evaluated in randomized trials. The inconsistent results have led to the publication of multiple meta-analyses. The present review examines the evidence from meta-analytic reports to determine whether MAB using agents such as flutamide, nilutamide, and cyproterone acetate (CPA) is associated with a survival advantage.

METHODS

We conducted a systematic review of the literature (MEDLINE, EMBASE, and the Cochrane Library through July 2004; CANCERLIT through October 2002) for meta-analyses that compared MAB with castration alone in previously untreated men with metastatic prostate cancer (D1 or D2, N+/M0 or M1). Two reviewers selected papers for eligibility; disagreement was resolved by all the authors through consensus.

RESULTS

The literature search identified six meta-analyses that met the eligibility criteria of the review. Two of those reports were based on individual patient data (IPD), and four were based on data from the published literature. All six meta-analyses pooled data on overall survival. The best evidence came from the largest meta-analysis, conducted by the Prostate Cancer Trialists Collaborative Group and based on IPD (8725 patients) from 27 trials. That analysis detected no difference in overall survival between mab and castration alone at 2 or 5 years. However, a subgroup analysis showed that MAB with nonsteroidal anti-androgens (NSAAS) was associated with a statistically significant improvement in 5-year survival over castration alone (27.6% vs. 24.7%; p = 0.005). The combination of MAB with CPA, a steroidal anti-androgen, was associated with a statistically significant increased risk of death (15.4% vs. 18.1%; p = 0.04). Compared with castration alone, MAB was associated with more side effects (that is, gastrointestinal, endocrine function) and reduced quality of life in domains related to treatment symptoms and emotional functioning.

CONCLUSIONS

The small survival benefit conferred by MAB with NSAA is of questionable clinical significance given the added toxicity and concomitant decline in quality of life observed in patients treated with MAB. Therefore, combined treatment with flutamide or nilutamide should not be routinely offered to patients with meta-static prostate cancer beyond the purpose of blocking testosterone flare. Monotherapy, consisting of orchiectomy or the administration of a luteinizing hormone-releasing hormone agonist is recommended as standard treatment.

Maximal Androgen Blockade for the Treatment of Metastatic Prostate Cancer—A Systematic Review

Introduction: Maximal androgen blockade (mab) versus castration alone in patients with metastatic prostate cancer has been extensively evaluated in randomized trials. The inconsistent results have led to the publication of multiple meta-analyses. The present review examines the evidence from meta-analytic reports to determine whether mab using agents such as flutamide, nilutamide, and cyproterone acetate (cpa) is associated with a survival advantage. Methods: We conducted a systematic review of the literature (medline, embase, and the Cochrane Library through July 2004; cancerlit through October 2002) for meta-analyses that compared mab with castration alone in previously untreated men with metastatic prostate cancer (D1 or D2, N+/M0 or M1). Two reviewers selected papers for eligibility; disagreement was resolved by all the authors through consensus. Results: The literature search identified six meta-analyses that met the eligibility criteria of the review. Two of those reports were based on individual patient data (ipd), and four were based on data from the published literature. All six meta-analyses pooled data on overall survival. The best evidence came from the largest meta-analysis, conducted by the Prostate Cancer Trialists Collaborative Group and based on ipd (8725 patients) from 27 trials. That analysis detected no difference in overall survival between mab and castration alone at 2 or 5 years. However, a subgroup analysis showed that mab with nonsteroidal anti-androgens (nsaas) was associated with a statistically significant improvement in 5-year survival over castration alone (27.6% vs. 24.7%; p = 0.005). The combination of mab with cpa, a steroidal anti-androgen, was associated with a statistically significant increased risk of death (15.4% vs. 18.1%; p = 0.04). Compared with castration alone, mab was associated with more side effects (that is, gastrointestinal, endocrine function) and reduced quality of life in domains related to treatment symptoms and emotional functioning. Conclusions: The small survival benefit conferred by mab with nsaa is of questionable clinical significance given the added toxicity and concomitant decline in quality of life observed in patients treated with mab. Therefore, combined treatment with flutamide or nilutamide should not be routinely offered to patients with meta-static prostate cancer beyond the purpose of blocking testosterone flare. Monotherapy, consisting of orchiectomy or the administration of a luteinizing hormone–releasing hormone agonist is recommended as standard treatment.

Effective palliative radiation therapy in advanced and recurrent ovarian carcinoma

PURPOSE

To retrospectively review our experience using radiation therapy as a palliative treatment in ovarian carcinoma.

METHODS AND MATERIALS

Eighty patients who received radiation therapy for ovarian carcinoma between 1983 and 1998 were reviewed. The indications for radiation therapy, radiation therapy techniques, details, tolerance, and response were recorded. A complete response required complete resolution of the patient's symptoms, radiographic findings, palpable mass, or CA-125 level. A partial response required at least 50% resolution of these parameters. The actuarial survival rates from initial diagnosis and from the completion of radiation therapy were calculated.

RESULTS

The median age of the patients was 67 years (range 26 to 90 years). A median of one laparotomy was performed before irradiation. Zero to 20 cycles of a platinum-based chemotherapy regimen were delivered before irradiation (median = 6 cycles). The reasons for palliative treatment were: pain (n = 22), mass (n = 23), obstruction of ureter, rectum, esophagus, or stomach (n = 12), a positive second-look laparotomy (n = 9), ascites (n = 8), vaginal bleeding (n = 6), rectal bleeding (n = 1), lymphedema (n = 3), skin involvement (n = 1), or brain metastases with symptoms (n = 11). Some patients received treatment for more than one indication. Treatment was directed to the abdomen or pelvis in 64 patients, to the brain in 11, and to other sites in 5. The overall response rate was 73%. Twenty-eight percent of the patients experienced a complete response of their symptoms, palpable mass, and/or CA-125 level. Forty-five percent had a partial response. Only 11% suffered progressive disease during therapy that required discontinuation of the treatment. Sixteen percent had stable disease. The duration of the responses and stable disease lasted until death except in 10 patients who experienced recurrence of their symptoms between 1 and 21 months (median = 9 months). The 1-, 2-, 3-, and 5-year actuarial survival rates from diagnosis were 89%, 73%, 42%, and 33%, respectively. The survival rates calculated from the completion of radiotherapy were 39%, 27%, 13%, and 10%, respectively. Five percent of patients experienced Grade 3 diarrhea, vomiting, myelosuppression, or fatigue. Fourteen percent of patients experienced Grade 1 or 2 diarrhea, 19% experienced Grade 1 or 2 nausea and vomiting, and 11% had Grade 1 or 2 myelosuppression.

CONCLUSIONS

In this series of radiation therapy for advanced ovarian carcinoma, the response, survival, and tolerance rates compare favorably to those reported for current second- and third-line chemotherapy regimens. Cooperative groups should consider evaluating prospectively the use of radiation therapy before nonplatinum and/or nonpaclitaxel chemotherapy in these patients.

Biphenylsulfonamide endothelin receptor antagonists. 2. Discovery of 4'-oxazolyl biphenylsulfonamides as a new class of potent, highly selective ET(A) antagonists

The synthesis and structure-activity relationship (SAR) studies of a series of 4'-oxazolyl-N-(3,4-dimethyl-5-isoxazolyl)[1, 1'-biphenyl]-2-sulfonamide derivatives as endothelin-A (ET(A)) receptor antagonists are described. The data reveal a remarkable improvement in potency and metabolic stability when the 4'-position of the biphenylsulfonamide is substituted with an oxazole ring. Additional 2'-substitution of an acylaminomethyl group further increased the binding activity and provided one of the first subnanomolar ET(A)-selective antagonists in the biphenylsulfonamide series (17, ET(A) K(i) = 0.2 nM). Among the compounds described, 3 (N-(3,4-dimethyl-5-isoxazolyl)-4'-(2-oxazolyl)[1, 1'-biphenyl]-2-sulfonamide; BMS-193884) had the optimum pharmacological profile and was therefore selected as a clinical candidate for studies in congestive heart failure.

Gonadotropin-releasing hormones in the brain and pituitary of the teleost, the white sucker

The present study investigated GnRH forms within the brain of a representative of the order Cypriniformes, the white sucker, Catostomus commersoni, using HPLC, RIA, and immunocytochemistry. Several immunoreactive (ir) GnRH forms were identified in the brain of the white sucker by chromatography and radioimmunoassay, including ir-salmon GnRH, ir-lamprey GnRH-I and -III, and ir-chicken GnRH-II. Results from immunocytochemical studies were consistent with multiple GnRH forms distributed in different patterns, particularly for fibers. Neuronal perikarya containing ir-salmon GnRH and ir-lamprey-like GnRH were found laterally within the preoptic area and rostral hypothalamus. Cells containing exclusively ir-salmon GnRH appeared slightly more rostrally, but in the same region. Fibers containing ir-salmon GnRH and ir-lamprey-like GnRH were seen throughout the caudal telencephalon and extended into the diencephalon, toward the pituitary. Fibers containing ir-chicken-II-like GnRH were also seen in the caudal telencephalon, but were concentrated more dorsally in the diencephalon. Within the pituitary, fibers containing ir-salmon GnRH and ir-lamprey-like GnRH entered the neurohypophysis, but differed in their destinations. Fibers containing ir-salmon GnRH remained within the neurohypophysis, while fibers containing ir-lamprey-like GnRH targeted adenohypophyseal tissue. These findings are consistent with the hypothesis that multiple GnRH forms with multiple functions exist within the brain and pituitary of teleosts and provide further evidence of a lamprey-like GnRH within an early evolved teleost species.

Biphenylsulfonamide endothelin antagonists: structure-activity relationships of a series of mono- and disubstituted analogues and pharmacology of the orally active endothelin antagonist 2'-amino-N- (3,4-dimethyl-5-isoxazolyl)-4'-(2-methylpropyl)[1, 1'-biphenyl]-2-sulfonamide (BMS-187308)

Substitution at the ortho position of N-(3,4-dimethyl-5-isoxazolyl) benzenesulfonamide led to the identification of the biphenylsulfonamides as a novel series of endothelin-A (ETA) selective antagonists. Appropriate substitutions on the pendant phenyl ring led to improved binding as well as functional activity. A hydrophobic group such as isobutyl or isopropoxyl was found to be optimal at the 4'-position. Introduction of an amino group at the 2'-position also led to improved analogues. Combination of the optimal 4'-isobutyl substituent with the 2'-amino function afforded an analogue (20, BMS-187308) with improved ETA binding affinity and functional activity. Compound 20 also has good oral activity in inhibiting the pressor effect caused by an ET-1 infusion in rats. Doses of 10 and 30 micromol/kg iv 20 attenuated the pressor responses due to the administration of exogenous ET-1 to conscious monkeys, indicating that the compound inhibits the in vivo activity of endothelin-1 in nonhuman primates.

Quantitation of tremor in response to beta-adrenergic receptor stimulation in primates: relationship with hypokalemia

The primary adverse effect of stimulation of beta2-adrenergic receptors is elicitation of tremor. Tremor measurements in response to beta2-adrenergic receptor stimulation were performed in a quantitative manner using a modified miniature semiconductor accelerometer in African green monkeys. The accelerometer was taped to the middle finger tip of anesthetized monkeys, and recordings of onset, duration and peak tremor responses were obtained. The selective beta2-adrenergic agonist, salbutamol (0.5 mg/kg i.v.), caused a marked increase in tremor which started within 5 min following injection and lasted for approximately 60 min. The finger tremor response was not visible, but was measurable by the accelerometer, and the increase in tremor was significantly greater from baseline within 10 min. Plasma K+ concentrations were markedly decreased within the first 15 min and remained at low steady-state concentrations during the 60-min recordings. The tremor response was abolished by the selective beta2-adrenergic receptor antagonist, ICI-118551 (0.2 mg/kg). ICI-118551 caused a significant reversal of the plasma K+ decrease but the K+ levels remained higher than control levels. These studies demonstrate that stimulation of beta2-adrenergic receptors causes tremor, most likely from entry of K+ into skeletal muscle and that there is a direct correlation between tremor and hypokalemic response.

Relationship between bone density and osteoarthritis in a skeletal population from London

To determine whether bone density was related to the presence of osteoarthritis in past populations, bone density was determined directly on bone slices taken from the fourth lumbar vertebra of a series of skeletons from a cemetery in London used from the middle 18th to the early 19th centuries. Eighty male and 57 female skeletons were studied and standard anthropological methods were used to determine age and gender. Osteoarthritis was diagnosed by the presence of eburnation on joint surfaces. The mean bone density in the males was 0.351 (+/-0.071) g/cm2, and in the females 0.332 (+/-0.091); this difference was statistically significant (p = 0.045). There was a significant, negative relationship with bone density and age in females (p = 0.0023), but not males (p = 0.073). Forty-seven of the males and 30 of the females had osteoarthritis, the most commonly affected joints being the facet joints of the spine and the hands. For the males there was no significant difference in bone density in those with or without osteoarthritis, but in females the bone density was significantly lower (p = 0.021) in those with osteoarthritis than in those without. The reasons why this result differs from modern populations in which patients with osteoarthritis tend to have higher bone density are discussed, and it is suggested that the most plausible explanation may relate to differences in nutritional status between past and modern populations.

Incidence and impact of light chain associated (AL) amyloidosis on the prognosis of patients with multiple myeloma treated with autologous transplantation

Little is known about the incidence of clinically occult AL amyloid in patients with multiple myeloma and its impact on prognosis of these patients. To address these issues, subcutaneous fat pad aspirates (SAFA) and bone marrow biopsies were evaluated for the presence of amyloid in a cohort of newly diagnosed patients with multiple myeloma prior to enrollment on a phase II study including tandem transplants. Organ directed biopsies were performed when clinically indicated. Presence of amyloid at > or = 1 site was noted in 32 patients (38%). SAFA was positive in 25 (31%), bone marrow in 8 patients (10%) and other organ sites in 7 patients. Patients with and without amyloid did not differ in disease characteristics, in particular no lambda predominance was observed in patients with amyloid. Event free survival (59+ vs 52 months; p = .9) and overall survival (59+ vs 66+ months; p = .9) were similar in both groups. Even the seven patients with symptomatic organ involvement with AL amyloid had a median overall survival of 38+ months. In conclusion, AL amyloidosis occurs more often than previously reported, but its presence does not influence the outcome of these patients after transplantation.

An epidemiologic study of sacroiliac fusion in some human skeletal remains

A case-control study was undertaken to generate some hypotheses concerning the etiology of sacroiliac fusion in a group of skeletons dating from the 18th and 19th centuries. Forty-one skeletons with fusion of the sacroiliac joint were compared with eighty-two adult skeletons without the condition. The sacroiliac joints were most frequently fused with bridging osteophytes and no preference for site or side of fusion could be detected. Except where there were other features in the skeleton suggestive of a sero-negative arthropathy, radiography demonstrated that there was no intra-articular ankylosis. We were able to confirm earlier observations that the condition is more prevalent in males and in older age-groups. The study also showed a significant association between sacroiliac fusion and the presence of diffuse idiopathic skeletal hyperostosis (DISH) and osteoarthritis of the spine but not for osteoarthritis at any other site. There was a highly significant association between sacroiliac fusion and the phenomenon that we refer to as "bone forming." We devised a series of bone-former scores and were able to show a significant excess of cases with high scores compared with the controls. This association persisted when allowance had been made for potential confounding factors such as DISH, osteoarthritis of the spine, and age.

DISH at Merton Priory: evidence for a "new" occupational disease?

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