Estrogens,but not androgens,regulate expression and functional activity of oxytocin receptor in rabbit epididymis

Previous binding and contractility studies indicate that oxytocin (OT) receptors are present in rabbit epididymis. To investigate the effect of changing endocrine milieu on OT responsiveness, we induced hypogonadism (hypo) in rabbits with a single administration of a long-acting GnRH analog, triptorelin, and we replaced hypogonadal rabbits with different sex steroids. After 2 months from triptorelin administration, testosterone (T) plasma levels were decreased and OT responsiveness abolished. Administration of T to hypo rabbits restored T plasma levels but not OT sensitivity. Because Western blot analysis indicated that both estrogen receptors and aromatase are expressed in the epididymis, we treated hypo rabbits with estradiol valerate (E2v). E2v not only completely restored OT responsiveness but also even amplified it. Accordingly, Northern and Western blot analysis indicated that both OT receptor gene and protein were strongly induced by E2v but not by T. Surprisingly, also the class I estrogen receptor antagonist, tamoxifen restored OT sensitivity in hypo rabbits. To verify whether endogenous estradiol is involved in the regulation of OT receptor responsiveness, we treated intact rabbits with an aromatase inhibitor, letrozole. Blocking aromatase activity almost completely abolished OT sensitivity. These findings suggest a new function of estrogens in the male: regulation of OT responsiveness in epididymis.     

Aberrant methylation of DAP-kinase in therapy-related acute myeloid leukemia and myelodysplastic syndromes

Death-associated protein kinase (DAP-kinase), a proapoptotic serine/threonine kinase, is a candidate tumor suppressor gene. We studied the methylation status of DAP-kinase of 194 bone marrow samples from 160 patients with acute myeloid leukemia (AML) and 34 with a myelodysplastic syndrome (MDS) at the time of initial diagnosis by polymerase chain reaction (PCR). Hypermethylation of DAP-kinase was present in 27.5% (44 of 160) of AML and in 47% (16 of 34) of MDS specimens and significantly correlated to loss of DAP-kinase expression (P =.008). It was significantly more frequent in AML secondary to therapy for other malignancies (s-AML; 14 of 29, 48.3%), as compared to de novo AML (30 of 131, 22.9%, P =.01). DAP-kinase hypermethylation in AML was associated with myelodysplastic changes in the bone marrow at the time of the initial diagnosis (P =.002) and with the presence of cytogenetic abnormalities (P =.02). Alteration in the apoptotic response due to the loss of DAP-kinase function may be an early event in the transformation pathway to secondary leukemia via myelodysplasia.     

Effects of coronary revascularisation on myocardial blood flow and coronary vasodilator reserve in hibernating myocardium

OBJECTIVE—Previous studies have suggested that resting myocardial blood flow is within normal limits in most chronically dysfunctional left ventricular segments which improve function after coronary artery revascularisation (hibernating myocardium). The aim of this study was to assess myocardial blood flow and coronary vasodilator reserve in hibernating myocardium before and after coronary revascularisation.
PATIENTS AND METHODS— 30 patients with multivessel coronary disease undergoing coronary revascularisation (21 patients with bypass grafting and nine with coronary angioplasty), and 21 age and sex matched healthy volunteers (controls). Myocardial blood flow (MBF, ml/min/g) was measured by positron emission tomography using oxygen-15 water at rest and after dipyridamole (MBFdip, 0.56 mg/kg in four minutes). Coronary vasodilator reserve was calculated as MBFdip/MBF. Regional wall motion was assessed with echocardiography.
RESULTS—Before revascularisation there were 48 remote and 275 dysfunctional myocardial segments, of which 163 (59%) improved function after revascularisation (hibernating). In hibernating segments coronary vasodilator reserve before revascularisation was significantly lower than in remote segments (1.97 (0.7), p < 0.0001) and controls (3.2 (1.5), p < 0.0001). In hibernating segments, myocardial blood flow remained unchanged after revascularisation (0.94 (0.3) v 0.95 (0.3) ml/min/g, p = 0.3) while coronary vasodilator reserve increased (1.47 (0.7) v 1.98 (1.0), p < 0.0001). Myocardial blood flow was similar in remote, hibernating segments before and after revascularisation and in controls.
CONCLUSIONS—This study confirms that myocardial blood flow at rest in hibernating myocardium is within normal limits in most segments, and that hibernating myocardium is characterised by an impaired coronary vasodilator reserve which improves significantly after coronary revascularisation.


Keywords: hibernating myocardium; myocardial blood flow; heart failure; positron emission tomography     

PML-RAR induces promyelocytic leukemias with high efficiency following retroviral gene transfer into purified murine hematopoietic progenitors

Acute promyelocytic leukemia (APL) is associated with chromosomal translocations resulting in fusion proteins of the retinoic acid receptor (RAR). Here, we report a novel murine model system for APL, based on the transduction of purified murine hematopoietic progenitors (lin(-)) using high-titer retroviral vectors encoding promyelocytic leukemia-RAR (PML-RAR), and the green fluorescent protein (GFP) as a marker. PML-RAR-expressing lin(-) cells were impaired in their ability to undergo terminal myeloid differentiation and showed increased proliferative potential in vitro. Inoculation of transduced lin(-) cells into syngeneic, irradiated mice resulted in the development of retinoic acid-sensitive promyelocytic leukemias at high frequency (> 80%) and short latency (approximately 4 months). Morphologic and immunophenotypic analysis revealed no gross abnormalities of the preleukemic bone marrows. However, hematopoietic progenitors from PML-RAR preleukemic mice showed a severe impairment in their ability to undergo myeloid differentiation in vitro. This result, together with the monoclonality or oligoclonality of the leukemic blasts, supports a "multiple-hit" model, where the fusion protein causes a "preleukemic" phase, and leukemia occurs after additional genetic lesions. This model system faithfully reproduces the main characteristics of human APL and represents a versatile tool for the in vitro and in vivo study of mechanisms of leukemogenesis and the design of protocols for differentiation treatment.     

Detection of autonomous replicating sequences (ars) in the genome of Epstein-Barr virus.

Epstein-Barr virus (EBV) DNA was analyzed for the presence of autonomous replicating sequences (designated ars) in a eukaryotic system consisting of a uracil auxotroph of Saccharomyces cerevisiae, YNN27, and a pBR322 hybrid plasmid, YIp5, containing the yeast uracil gene but apparently lacking a eukaryotic origin of replication. Cloned EBV DNA EcoRI restriction fragments, A, B, and DIJhet, were judged to function in this capacity by their ability to convert YNN27 cells to the uracil phenotype after transformation with each EBV-specific fragment ligated into YIp5. Additional analyses to confirm and to specify further the location of the ars were performed by cleavage of EcoRI fragments A and B into smaller BamHI fragments, which were subsequently cloned in YIp5 and tested for their ability to function as ars. BamHI fragment X, obtained from EcoRI fragment A, and BamHI fragment R, obtained from EcoRI fragment B, showed ars behavior. The successful recovery of the appropriate virus DNA segments in plasmid form from transformed yeast cells and the ability of these yeast cells to be propagated further substantiated the ars capability of the three EBV fragments.     

Comparative analysis of the incidence of surgical site infections in patients with liver resection for colorectal hepatic metastases after neoadjuvant chemotherapy

Background

The aim of this study was to identify the incidence of surgical site infections (SSIs) and postoperative complications, as defined by the Clavien–Dindo classification, after hepatic resection for metastatic colorectal cancer in patients with and without associated neoadjuvant chemotherapy.

Methods

A total of 181 patients were studied retrospectively. Patients were divided into two groups: the first group comprised patients with associated neoadjuvant chemotherapeutic treatment for liver metastases with a latency time <8 wk and the second group comprised patients without associated neoadjuvant chemotherapy.

Results

Variables of duration of liver surgery, length of total hospital stay, and length of postoperative hospital stay seem to be correlated with SSIs and postoperative complications, P < 0.005 and P < 0.0001, respectively. Duration of surgery is a risk factor for SSIs, with an odds ratio of 1.15, and for complications according to the Clavien–Dindo classification, with an odds ratio of 1.35.

Conclusions

Neoadjuvant chemotherapy was not a significant risk factor for SSIs, whereas the total length of hospital stay, length of postoperative hospital stay, and duration of surgery were independent predictors of SSIs and complications according to the Clavien–Dindo classification.     

The Bolognese surgeon Giuseppe Ruggi: how and why the aseptic surgery was introduced in Bologna in the middle half of the XIX century

Background

The first reliable statistic data about perioperatory mortality were published in 1841 by the French Joseph-Francois Malgaigne (1806–1863): he referred to a mean mortality of 60% for amputations and this bad result was to be attributed mainly to hospital acquired diseases. The idea of “hospital acquired disease” although vague, included five infective nosologic entities, which at that time were diagnosed more frequently: erysipelas, tetan, pyemia, septicemia, and gangrene. Nonetheless, the suppuration with pus production was considered from most of the surgeons and doctors of that time as a necessary and unavoidable step in the process of wound healing. During the end of the eighteenth century, hospitals of the main European cities were transforming into aggregations of several wards, where the high concentration of patients created poor sanitary conditions and a consistent increase of perioperatory mortality. In 1865, Lister applied his first antiseptic dressing on the surface of an exposed fracture. These experimental attempts lead to an effective reduction of wound infections respect to the dressing with strings used previously.

Discussion

Lister's innovations in the field of wound treatment were based on two brand new concepts: germs causing rot were ubiquitarious and the wound infection was not a normal step in the process of wound healing. The concept of antisepsis was hardly accepted in the European surgical world: “Of all countries, Italy is the most indifferent and uninterested in experimenting this method, which has been so favorably judged from the greatest surgical societies in Germany”. This quotation from the young surgeon Giuseppe Ruggi (1844–1925) from Bologna comes from his article where he presented his first experiences on aseptic medications started the previous year in the Surgical Department of Maggiore Hospital in Bologna. In his report, Ruggi described the adopted technique and suggested that the medication should be extended to all the surgical patients of the hospital:“… this is needed to totally remove from the hospital all those elements of infection which grow in the wounds dressed with the old method”. The experimentation of this new dressing for the few treated cases was rigorous and concerned both the sterilization of surgical tools with the fenic acid (5%) and the shaving of the skin. Ruggi also observed that there was no correlation between the seriousness of the wound and its extension or way of healing: when “simple” cases that “should heal without complication” showed fever he often realized that “it was often due to a medication performed without following the rules for an accurate disinfection and dressing”. Ruggi thought that the fever was connected to “reabsorption of pyrogenic substances, which can be removed cleaning and disinfecting the wound” in cases of wounds not accurately dressed and rarely medicated. Frequent postoperative medications of the wound were able to eliminate the fever within 2 h. Ruggi's attitude toward the fine reasoning lead him to introduce the concept of immunodeficiency related to physical deterioration: “… patients treated for surgical disease may sometimes suffer from complications of medical conditions, which initially escape the most accurate investigations… The surgical operation could, in some cases, hold the balance of power”.

Conclusions

The obtained results, published in 1879, appear extremely interesting. As he wrote in 1898, for the presentation of his case record of more than 1000 laparotomies, he had started “… operating as a young surgeon without any tutor, helped only by his mind and what he could deduce from publications existing at the moment …”.     

Extending cluster lot quality assurance sampling designs for surveillance programs

Lot quality assurance sampling (LQAS) has a long history of applications in industrial quality control. LQAS is frequently used for rapid surveillance in global health settings, with areas classified as poor or acceptable performance on the basis of the binary classification of an indicator. Historically, LQAS surveys have relied on simple random samples from the population; however, implementing two‐stage cluster designs for surveillance sampling is often more cost‐effective than simple random sampling. By applying survey sampling results to the binary classification procedure, we develop a simple and flexible nonparametric procedure to incorporate clustering effects into the LQAS sample design to appropriately inflate the sample size, accommodating finite numbers of clusters in the population when relevant. We use this framework to then discuss principled selection of survey design parameters in longitudinal surveillance programs. We apply this framework to design surveys to detect rises in malnutrition prevalence in nutrition surveillance programs in Kenya and South Sudan, accounting for clustering within villages. By combining historical information with data from previous surveys, we design surveys to detect spikes in the childhood malnutrition rate. Copyright © 2014 John Wiley & Sons, Ltd.