Prognostic relevance of histological grade and its components in node-negative breast cancer patients.

Available results highlight the lack of good level of evidence studies on the pure prognostic value of histological grade. In the present study, the prognostic relevance of histological grade and of its three components, tubule formation, nuclear pleomorphism and mitotic count, was analyzed in a series of 372 patients with node-negative breast cancer treated with locoregional therapy alone until early relapse. Histological grade was determined blindly by two observers and discordance between evaluations was resolved after joint review using a multihead microscope. No relation was observed between histological grade and any of its three components and disease-free survival. Conversely, a significant relation was observed between histological grade and distant metastasis-free survival (at 6 years, 94, 86 and 76% for grades 1, 2 and 3, respectively, P=0.013) as well as overall survival (98, 90 and 86%, P=0.001). A breakdown analysis as a function of the three components showed that neither tubule formation nor nuclear pleomorphism was associated with prognosis, and only mitotic count strongly influenced both distant metastasis-free survival (91, 82 and 74%, P=0.014) and overall survival (97, 87 and 85%, P=0.011). Histological grade suffers from a much higher subjectivity than any other microscopic evaluation of biomarkers as it is the sum of three different morphological features. Within the Italian Network for Quality Assessment of Tumor Biomarkers program we observed that histological grade is an independent prognostic variable, but also that this role is ascribable only to the number of mitotic figures. In conclusion, due to the ever smaller size of diagnosed breast cancers, resulting in less cancer tissue for biofunctional and molecular analysis, mitotic count evaluated under strict quality control conditions seems to be an accurate and feasible prognostic variable.     

Pharmacokinetics and dialysability of isradipine in chronic haemodialysis patients

Summary The pharmacokinetics of isradipine, a calcium-channel blocker, have been studied in eight patients on chronic haemodialysis. A single oral dose of 5 mg was administered on both a non-haemodialysis and a haemodialysis day and the plasma concentrations of isradipine were analyzed.The mean c_max, t_max, AUC, and t_1/2 in plasma on the non-haemodialysis day were 5.2 ng·ml^–1, 1.4 h, 23.8 ng·h·ml^–1, and 3.1 h, respectively. The dialysis clearance of isradipine was negligible (5.0 ml·min^–1).The t_1/2 values during haemodialysis were not significantly different from those observed during the same period post dose on the non-haemodialysis day. The study demonstrates that supplemental doses of isradipine are not necessary in these patients since isradipine is not significantly removed by haemodialysis.     

Effects of antisense mediated inhibition of cathepsin K on human osteoclasts obtained from peripheral blood.

Cathepsin K is a cystein protease that displays a proteolytic activity against Type I collagen and is abundantly and selectively expressed in osteoclasts where it plays a critical role in bone degradation. Its direct role in bone tissue has been defined by knock-out mice studies and inhibiting strategies in animals models. However, direct proof of cathepsin K function in human osteoclast model in vitro is lacking. The aim of this study is to analyze cathepsin K expression and localization in human osteoclasts obtained from peripheral blood and to examine cathepsin K function in these cells by antisense oligodeoxynucleotide (AS-ODN) strategy. AS-ODN was added to the culture of osteoclast precursors induced to differentiate by RANKL and M-CSF. AS-ODN treatment produced a significant down-regulation of cathepsin K mRNA (>80%) and protein expression, as verified respectively by Real-time PCR and by immunocytochemistry or Western blot. The cathepsin K inhibition caused an impairment of resorption activity as evaluated by a pit formation assay ( p = 0.045) and by electron microscopy, while the acidification process was unaffected. We demonstrated that antisense strategies against cathepsin K are selectively effective to inhibit resorption activity in human osteoclasts, like in animal models.     

A multicenter evaluation of safety of early extubation in liver transplant recipients.

Small single-institutional studies performed prior to the introduction of organ allocation using the Model for End-Stage Liver Disease (MELD) suggest that early airway extubation of liver transplant recipients is a safe practice. We designed a multicenter study to examine adverse events associated with early extubation in patients selected for liver transplantation using MELD score. A total of 7 institutions extubated all patients meeting study criteria and reported adverse events that occurred within 72 hours following surgery. Adverse events were uncommon: occurring in only 7.7% of 391 patients studied. Most adverse events were pulmonary or surgically related. Pulmonary complications were usually minor, requiring only an increase in ambient oxygen concentration. The majority of surgical adverse events required additional surgery. Analysis of a limited set of perioperative variables suggest that blood transfusions and technical factors were associated with an increased risk of adverse events. In conclusion, while early extubation appears to be safe under specified circumstances, there are performance differences between institutions that remain to be explained.     

Metabolic consequences of physical inactivity.

Physical inactivity is associated with alteration of normal physiologic processes leading to muscle atrophy, reduced exercise capacity, insulin resistance, and altered energy balance. Bed rest studies in human beings using stable isotopes of amino acids indicate that muscle unloading decreases the turnover rates of muscle and whole-body proteins, with a prevailing inhibition of protein synthesis. In the fasting state, muscle and whole-body nitrogen loss was not accelerated during bed rest. In experimental postprandial states, the amino acid-mediated stimulation of protein synthesis was impaired, whereas the ability of combined insulin and glucose infusion to decrease whole-body proteolysis was not affected by muscle inactivity. Thus, an impaired ability of protein/amino acid feeding to stimulate body protein synthesis is the major catabolic mechanism for the effect of bed rest on protein metabolism. This suggests that a protein intake level greater than normal could be required to achieve the same postprandial anabolic effect during muscle inactivity. Metabolic adaptation to muscle inactivity also involves development of resistance to the glucoregulatory action of insulin, decreased energy requirements, and increased insulin and leptin secretion. These alterations may lead to the development of the metabolic syndrome that is defined as the association of hyperinsulinemia, dyslipidemia, hypertension, hyperglycemia, and abdominal obesity. This cluster of metabolic abnormalities is a risk factor for coronary artery disease and stroke. Evidence indicates that exercise training programs may counteract all of these abnormalities both in healthy sedentary subjects and in patients affected by a variety of chronic disease states.     

Localization of parathyroid enlargement: experience with technetium-99m methoxyisobutylisonitrile and thallium-201 scintigraphy,ultrasonography and computed tomography

Technetium-99m methoxyisobutylisonitrile (MIBI), like thallium-201, has recently been introduced as a myocardial perfusion agent and is now also showing very promising results in parathyroid scintigrapy. The results of ²⁰¹Tl/^99mTc-pertechnetate and ^99mTc-MIBI/^99mTc-pertechnetate subtraction scintigraphy, ultrasonography and computed tomography are presented in a series of 43 patients operated on for hyperparathyroidism. All four imaging modalities were confirmed to be reliable, scintigraphy being the most accurate. Sensitivities ranged from 81% to 95%, that of ^99mTc-MIBI being the highest. Moreover this tracer, which has more favourable physical and also biochemical properties, yielded images of superior quality. This allowed localization of the lesion by visual inspection only in as many as 86% of the patients with positive ^99mTc-MIBI/^99mTc-pertechnetate subtraction scintigraphy. We believe that the higher sensitivity, superior image quality and lower cost of ^99mTc-MIBI imaging will make ^99mTc-MIBI the new radiopharmaceutical of choice for parathyroid scintigraphy (when one takes into account the stability of labelling with large activities it is possible to perform three or four cardiac studies together with one parathyroid scintigraphic examination using one lyophililzed vial).     

Sequence dependence of the antitumor and toxic effects of 5-fluorouracil and cis-diamminedichloroplatinum combination on primary colon tumors in mice

Summary Primary colon tumors of different sizes and malignancy, chemically induced by methylazoxymethanol in outbred CF-1 mice, were used to investigate the antitumor effects of 5-Fluorouracil (5FU) and cis-diammine-dichloroplatinum (DDP), given weekly i.v. as single agents or in combination. When single-drug chemotherapy was tested, DDP showed higher efficacy than 5FU. In fact, in two separate experiments a significant reduction (P(0.05) of tumor number (TN) and tumor burden was obtained by treatment with the optimal dose of DDP (4.5 mg/kg per injection) and not by that of 5FU (52 mg/kg). When the two drugs were combined (24-h interval), studies carried out on healthy mice treated weekly i.v. showed a lower toxicity with the same doses given in the sequence 5FU-DDP than in the opposite sequence. The two drugs, delivered in the sequence 5FU followed by DDP, statistically reduced the TN and total tumor burden compared to control mice (P(0.05). On the other hand, the same doses in the sequence DDP followed by 5FU did not attain significant tumor reduction. The sequence dependence of the activity and toxicity of the 5FU and DDP combination observed in this experimental model should be taken into account in the design of clinical trials.Abbreviations used MAM methylazoxymethanol acetate - 5FU 5Fluorouracil - DDP cis-diamminedichloroplatinum - TN tumor number - TTB total tumor burden - Ara-C cytosine-arabinoside This work was partially supported by Grant N. 84.00746.44 of Finalized Project Oncology of CNR (Rome, Italy)     

Heterogeneity of human basophils and mast cells in response to muscle relaxants

We investigated thein vitro effects of increasing concentrations (10^–5–10^–3 M) of four muscle relaxants (succinylcholine, d-tubocurarine, vecuronium and atracurium) on histamine release (HR) from human peripheral blood basophils and mast cells isolated from lung parenchyma (HLMC) and skin tissues (HSMC). Basophils released less than 5% of their histamine content when incubated with any one of the muscle relaxants. In contrast, mast cells showed a marked heterogeneity in their response. Succinylcholine did not induce HR from any type of mast cell, and only high concentrations of d-tubocurarine (10^–3 M) caused HR from HSMC and HLMC. Vecuronium concentration-dependently induced HR from HLMC and HSMC. Atracurium concentration-dependently caused marked HR from HLMC and HSMC up to a maximum of 46.2±15.1% and 30.6±6.0%, respectively. From both HLMC and HSMC HR caused by atracurium and vecuronium was extremely rapid (t_1/2<1 min).=" the=" releasing=" activity=" of=" atracurium=" and=" vecuronium=" on=" hlmc=" and=" hsmc=" was=" reduced,=" but=" not=" abolished,=" by=" lowering=" the=" temperature=" of=" the=" incubation=" buffer=" to=" 22°c=" and=" 4°c.=" these=" results=" confirm=" that=" there=" are=" functional=" differences=" between=" human=" basophils=" and=" mast=" cells=" and=" among=" mast=" cells=" isolated=" from=" different=" anatomical=" sites=" in=" response=" to=" the=" muscle=" relaxants=">