Lorentz microscopy sheds light on the role of dipolar interactions in magnetic hyperthermia

Monodispersed Fe3O4 nanoparticles with comparable size distributions have been synthesized by two different synthesis routes, co-precipitation and thermal decomposition. Thanks to the different steric stabilizations, the described samples can be considered as a model system to investigate the effects of magnetic dipolar interactions on the aggregation states of the nanoparticles. Moreover, the presence of magnetic dipolar interactions can strongly affect the nanoparticle efficiency as a hyperthermic mediator. In this paper, we present a novel way to visualize and map the magnetic dipolar interactions in different kinds of nanoparticle aggregates by the use of Lorentz microscopy, an easy and reliable in-line electron holographic technique. By exploiting Lorentz microscopy, which is complementary to the magnetic measurements, it is possible to correlate the interaction degrees of magnetic nanoparticles with their magnetic behaviors. In particular, we demonstrate that Lorentz microscopy is successful in visualizing the magnetic configurations stabilized by dipolar interactions, thus paving the way to the comprehension of the power loss mechanisms for different nanoparticle aggregates.

Is squamous cell histology an adverse prognosticator for survival of malignancies of the upper urinary tract?

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Background: Carcinomas of the renal pelvis and ureter are rare diseases, accounting for only about 1% of all urogenital malignancies. Previous reports suggest that squamous cell histology is associated with inferior survival. We present the largest population based analysis to date of survival in patients with upper urinary tract malignancies. Methods: We analyzed the Surveillance, Epidemiology and End Results database for cancer specific survival rates in patients with renal pelvis and ureteral malignancies who were diagnosed between 1973 and 2003 in the SEER catchment geographic areas. The primary exposure of interest was the underlying histology, squamous cell versus transitional cell differentiation. We performed descriptive statistics, non parametric survival analysis, and cox proportional hazard analysis. Results: We identified 13,213 eligible patients, 7,716 renal pelvis and 5,497 ureteral carcinomas. Among this cohort, 179 patients had squamous cell carcinoma (SCC), 12,395 had transitional cell carcinoma (TCC), including 121 papillary, and 619 had other histologies. Overall, patients with SCC histology fared worse. The median overall survival time was 10 months for SCC and 63 months for TCC. The cox analysis revealed a HR 0.42 (95% CI 0.36–0.47) for TCC when compared to SCC and corrected for decade of diagnosis, age, gender, prior treatment, and race. The difference between the two groups was entirely attributable to survival differences in patients with loco-regional disease. However, when stratified by lymph node involvement this difference disappeared for patients with locally involved lymph nodes (p = 0.84) and for patients with clear lymph nodes (p = 0.92). Conclusions: SCCs of the upper urinary tract present at a higher clinical stage and appear to represent more aggressive disease when compared to other histologies. However, when appropriately staged according to lymph node status, the survival of TCC and SCC of the upper urinary tract is identical when compared stage by stage.

No significant financial relationships to disclose.

Are we training our fellows adequately in delivering bad news to patients? A survey of hematology/oncology program directors

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Background: Medical Oncologists are often in a situation of delivering bad news (dbn). We were interested in the extent of formal training in dbn in Hematology/Oncology fellowships in the United States. Methods: An e-mail survey was conducted of all Hematology/Oncology Program Directors (PDs) in the United States to elicit subjective responses as to the degree of formal training fellows receive in dbn, the adequacy, perceived necessity and quality of this training as well as institutional support provided. The surveys were e- mailed to 124 PDs and responses were received either via e-mail or regular mail. Results: 49 surveys were completed and returned (40% response rate). The majority of programs, 82%, are in an urban setting and 96% of the primary teaching hospitals are considered tertiary care centers. 45% of programs carry an NCI designation; the median number of fellows in a training program is 6, with the range being 3 to 42. 90% of PDs reported that they received little to no formal training in dbn. In contrast, they report that 31% of current fellows receive little to no formal training with 43% receiving some training and additional 26% receiving moderate to extensive training. 36% of PDs felt that formal training is important for skill development in dbn while only 4% did not feel so and an additional 31% felt that some training is useful. 50% of PDs would like to see some improvements in how their fellows are trained and 28% would like to see moderate to extensive improvement. 44% reported little to no institutional support for training while 22% reported moderate to full support. Conclusions: Of the Hematology/Oncology Program Directors who responded to our survey, a large majority did not have formal training in dbn. Despite this lack of training, most PDs felt that some training was useful for skill development in dbn and the majority of today's fellows do receive training in delivering bad news. However, there was still a significant percentage of PDs who reported little or no formal training for fellows and most PDs would still like to see some improvements in how fellows are trained. Specific institutional support for training fellows in dbn remains lacking.

No significant financial relationships to disclose.

Impact of carbapenem administration on systemic endotoxemia in patients with severe sepsis and Gram-negative bacteremia

In order to investigate the effect of carbapenems on systemic endotoxemia, 20 patients with severe sepsis due to ventilator-associated pneumonia and Gram-negative bacteremia were enrolled; 10 (group A) were administered 1 g t.i.d. of imipenem/cilastatin and 10 (group B) 2 g t.i.d. of meropenem. Blood was sampled at 0 time and after 1, 2, 4, 6, 12, 24, 36, 48, 60, 72, 84 and 96 hours for detection of endotoxins (LPS), interleukin-6 (IL-6), C-reactive protein (CRP) and drug levels. LPS were determined by the QCL-1000 LAL assay, IL-6 by an enzymeimmunoassay, CRP by nephelometry and carbapenem levels by a microbiological assay. We did not find that carbapenems had any effect on the kinetics of LPS and CRP; IL-6 of group A was lower than group B at 72 and 84 hours. No correlation was observed between drug levels of any carbapenem and LPS, IL-6 or CRP. It is concluded that in septic patients with Gram-negative bacteremia administration of either imipenem or meropenem did not affect systemic endotoxemia. The above data support the safe administration of both carbapenems in patients with severe sepsis.

Extracorporeal shock wave lithotripsy for clearance of refractory bile duct stones

BACKGROUND AND STUDY AIMS

Following endoscopic sphincterotomy, 90% of bile duct stones can be removed with a Dormia basket or balloon catheter. The removal can fail in patients with large stones, intrahepatic stones, bile duct strictures or a difficult anatomy. The aim of this retrospective study is to investigate the efficacy and safety of extracorporeal shock wave lithotripsy in fragmenting and allowing the extraction of bile duct stones that could not be cleared by routine endoscopic means including mechanical lithotripsy.

PATIENTS AND METHODS

From 1989 to January 2005, we treated with extracorporeal shock wave lithotripsy 376 patients (133 males and 243 females, median age 71.4 years) with bile duct stones that were not removable following endoscopic sphincterotomy, using the extracorporeal shock wave lithotripsy Lithostar Plus machine built by Siemens Co. of Erlangen, Germany. Stone targeting was performed fluoroscopically following injection of contrast via nasobiliary drain or T-tube in 362 patients and by ultrasonography in eight patients. Residual fragments were cleared at endoscopic retrograde cholangiopancreatograhy. Two hundred and ten of the 370 patients treated (56.7%) showed only 1 stone, 57 (15.4%) showed 2, 45 (12.1%) showed 3, 58 (15.6%) showed more than 3 stones. The median diameter of the stones was 21mm (range 7-80mm).

RESULTS

Complete stone clearance was achieved in 334 of the 376 patients who underwent the extracorporeal shock wave lithotripsy procedure (90.2%). Six patients (1.5%) dropped out of treatment during their first sessions, mainly because of intolerance. Each patient averaged 3.7 treatments (1-12), at an average rate of 3470 shocks per session (1500-5400), at an average energy level of 3.4mJ (1-7). Complications were recorded in 34 patients (9.1%); 22 patients experienced symptomatic cardiac arrhythmia, 4 haemobilia, 2 cholangitis, 3 haematuria, 3 dyspnoea; no deaths were associated with the procedure.

CONCLUSIONS

Extracorporeal shock wave lithotripsy is a safe and effective therapy in those patients in whom endoscopic techniques have failed with a clearing rate of 90.2% of refractory bile duct stones with a low rate of complications.

Cryotherapy in the prevention of oral mucositis in patients receiving low-dose methotrexate following myeloablative allogeneic stem cell transplantation: a prospective randomized study of the Gruppo Italiano Trapianto di Midollo Osseo nurses group

Severe oral mucositis is a major cause of morbidity following allogeneic hematopoietic stem cell transplantation (AHSCT). Cryotherapy, that is, the application of ice chips on the mucosa of the oral cavity during the administration of antineoplastic agents, may reduce the incidence and severity of chemotherapy-related oral mucositis. In this multicenter randomized study, we addressed whether cryotherapy during MTX administration is effective in the prevention of severe oral mucositis in patients undergoing myeloablative AHSCT. One hundred and thirty patients undergoing myeloablative AHSCT and MTX-containing GVHD prophylaxis were enrolled and randomized to receive or not receive cryotherapy during MTX administration. The incidence of severe (grade 3-4) oral mucositis, the primary end point of the study, was comparable in patients receiving or not cryotherapy. Moreover, no difference was observed in the incidence of oral mucositis grade 2-4 and the duration of oral mucositis grade 3-4 or 2-4, or in the kinetics of mucositis over time. In univariate and multivariate analysis, severe oral mucositis correlated with TBI in the conditioning regimen and lack of folinic acid rescue following MTX administration. Thus, cryotherapy during MTX administration does not reduce severe oral mucositis in patients undergoing myeloablative allogeneic HSCT. Future studies will assess cryotherapy before allogeneic HSCT.

Bone metabolism and gonad function in male patients undergoing liver transplantation: a two-year longitudinal study

Osteodystrophy is a major complication of end-stage liver disease, especially in postmenopausal women. Our aim in this study was to evaluate bone metabolism and gonad function in men undergoing orthotopic liver transplantation (OLTx). Twenty-three consecutive men (mean age 48+/-13 years) evaluated for OLTx were studied, assessing the following parameters at baseline and 3, 6, 12 and 24 months after OLTx: lumbar spine (L2-L4) bone mineral density (BMD), parathyroid hormone (PTH), osteocalcin (BGP), 25-hydroxyvitamin D (25OHD), free testosterone (FT) and gonadotropins (FSH, LH). At baseline, 12 patients (52%) had a T-score <-2.5 SD and the mean BMD was 0.806+/-0.11 g/cm2 (range 0.470-1.045 g/cm2). The BMD was lower 3 months after OLTx and significantly higher 12 and 24 months after OLTx. A significant increase in serum BGP was observed at 6, 12 (p<0.05) and 24 months (p<0.005) after OLTx. The mean serum PTH level was 26.6+/-3.1 pg/ml at baseline and increased significantly at 12 and 24 months (to 49.4+/-9.9 and 61.2+/-10.1 pg/ml, respectively; p<0.05). 25OHD serum levels were low at baseline and returned to the normal range after 12 and 24 months (baseline, 8.73+/-1.54 ng/ ml; 12 months, 16.4+/-2.6 ng/ml; 24 months, 17.67+/-3.1 ng/ml; p<0.05). FT was significantly lower at baseline than in a group of 10 healthy controls (5.09+/-10.99. vs 10.3+/-1.1 pg/ml; p<0.0001). After OLTx a significant increase in FT was recorded at 6, (p<0.05) and 24 months (p<0.005). FT was not correlated with BMD, however. After OLTx an increase in FSH and LH was observed (but failed to reach statistical significance) at 3 and 6 months, followed by a slight reduction at 12 and 24 months. Thus a high proportion of men with end-stage liver disease do have osteoporosis. After OLTx, an early recovery of gonad function is observed, followed by an increase in bone mass, which occurs from the sixth month onward.

Occurrence of both t(1;19) and t(8;14) in a patient with chronic lymphocytic leukemia

While t(1;19) and t(8;14) have been reported singly in pre-B-ALL and Burkitt's lymphoma, respectively, the occurrence of both translocations simultaneously in the same patient is rare. Indeed, a review of the English literature from 1966 to 1999 revealed no case reports with these findings. We report here an 88-year-old patient who was clinically diagnosed to have chronic lymphocytic leukemia and who carried both translocations in her peripheral blood cells. The patient refused to give consent for a bone marrow sample, the preferred tissue for study. The patient's clinical findings are discussed, although the relationship between the clinical information and cytogenetic findings, if any, is not known. Study of additional cases identical to ours will be helpful in determining the correlation, if any, between the patient's phenotype and the occurrence of the two translocations.

Persistent parvovirus B19 related anemia of seven years' duration in an HIV-infected patient: complete remission associated with highly active antiretroviral therapy

A human immunodeficiency virus (HIV)-infected individual was first diagnosed with red blood cell aplasia due to B19 parvovirus infection in late 1989. Over the subsequent seven-year period, he received a total of 119 units of red blood cells (RBCs) and intravenous immunoglobulin every 2-3 weeks. In 1996 combination antiretroviral treatment with a protease inhibitor was initiated. He received four more units during the following two months and then required no more transfusions for the subsequent 24 months of follow-up. His CD4 count progressively increased and DNA polymerase chain reaction for parvovirus B19 became undetectable. Aggressive antiretroviral treatment may effectively diminish transfusion requirements among HIV-infected individuals with pure RBC aplasia resulting from parvovirus B19 infection.

Paclitaxel and concurrent radiation for locally advanced pancreatic carcinoma

An effective local-regional therapy is needed for adenocarcinomas of the pancreas. Paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton NJ) may enhance the effect of radiation therapy. Paclitaxel synchronizes cells at G2/M, a relatively radiosensitive phase of the cell cycle. We have shown that response to paclitaxel and concurrent radiation (paclitaxel/RT) was not affected by p53 mutations in non-small cell lung cancer (NSCLC). This suggested that paclitaxel/RT was a rationale treatment approach for other malignancies which frequently harbor p53 mutations such as upper gastrointestinal malignancies. We have completed a phase I study of paclitaxel/RT for locally advanced pancreatic and gastric cancers. The maximum tolerated dose (MTD) of paclitaxel was 50 mg/m2/week for 6 weeks with abdominal radiation. The dose limiting toxicities were abdominal pain within the radiation field, nausea and anorexia. Twenty-five patients with locally advanced pancreatic cancer have now completed treatment at the phase II dose level of paclitaxel 50 mg/m2/week with 50 Gy concurrent RT. Thus far, the only grade 3/4 toxicities have been hypersensitivity reactions in 2 patients, asymptomatic grade 4 neutropenia in 3 patients, and non-neutropenic biliary sepsis in 1 patient. Of the first 22 assessable patients treated at the phase II study, 8 obtained a partial response (PR) for a preliminary response rate of 36%. These findings demonstrate that paclitaxel/RT is well tolerated with substantial activity for locally advanced pancreatic cancer.

Determinants of case selection at morning report

OBJECTIVE

To determine why residents present certain cases and not others at morning report (MR) in an institution that permits residents the free choice of cases.

DESIGN/PARTICIPANTS

Prospective survey of 10 second- and third-year residents assigned to the medical service.

SETTING

A 241-bed teaching hospital with 55 categorical internal medicine residents.

MEASUREMENTS AND MAIN RESULTS

Over a 4-week period, there were 194 admissions to the medical service on 18 call days preceding MR. Of these admissions, 30 (15%) were presented at MR. Cases were more likely to be presented if they were considered unusual or rare in presentation or incidence (P = .001), involved significant management issues (p = .001), or were associated with remarkable imaging studies or other visual material (p = .006). Residents were more likely to present cases in which they disagreed with attending physicians on management plans (p = .005). Overall, residents rated few admissions as having notable physical examination findings (29/194) or ethical or cost issues (6/194). Of the seven most common admitting diagnoses, representing 44% of admissions, residents did not present cases involving four of these diagnoses.

CONCLUSIONS

Residents presented cases at MR that they felt were unique or rare in presentation or incidence for purposes of discussing management issues. Complete resident freedom in choosing MR cases may narrow the scope of MR and exclude common diagnoses and other issues of import such as medical ethics or economics.

Noninvasive measurement of forearm blood flow and oxygen consumption by near-infrared spectroscopy

We applied near-infrared spectroscopy (NIRS) for the simultaneous measurement of forearm blood flow (FBF) and oxygen consumption (VO2) in the human by inducing a 50-mmHg venous occlusion. Eleven healthy subjects were studied both at rest and after hand exercise during vascular occlusion. FBF was also measured by strain-gauge plethysmography. FBF measured by NIRS was 1.9 +/- 0.8 ml.100 ml-1.min-1 at rest and 8.2 +/- 2.9 ml.100 ml-1.min-1 after hand exercise. These values showed a correlation (r = 0.94) with those obtained by the plethysmography. VO2 values were 4.6 +/- 1.3 microM O2 x 100 ml-1.min-1 at rest and 24.9 +/- 11.2 microM O2 x 100 ml-1.min-1 after hand exercise. The scatter of the FBF and VO2 values showed a good correlation between the two variables (r = 0.93). The results demonstrate that NIRS provides the particular advantage of obtaining the contemporary evaluation of blood flow and VO2, allowing correlation of these two variables by a single maneuver without discomfort for the subject.

Rostral ventrolateral medulla muscarinic receptor involvement in central ventilatory chemosensitivity

The muscarinic receptor antagonist atropine (105 mM) dramatically decreased the response to increased CO2 when applied by cotton pledgets to the rostral ventrolateral medulla ventilatory chemosensitive area in anesthetized, paralyzed, vagotomized, glomectomized, and servoventilated cats with integrated phrenic nerve activity used as respiratory center output. Lower dose atropine (4.4 mM) and the M1-muscarinic receptor subtype antagonist pirenzepine (10 mM) also significantly decreased the mean CO2 response slope 48.3 +/- 6.2 and 40.7 +/- 6.0% (SE), respectively, and significantly decreased the maximum response value 26.3 +/- 8.1 and 19.2 +/- 3.2%, respectively, without significant effects on blood pressure or on the phrenic response to carotid sinus nerve stimulation. The M2-muscarinic receptor subtype antagonist AF-DX 116 (10 mM) had no significant effect on phrenic output or blood pressure. Application of carbachol (10 mM) at the rostral area augmented eucapnic phrenic output and the maximum value of the CO2 response but decreased the initial slope, effects blocked by atropine. Carbachol also decreased the response to carotid sinus nerve stimulation, suggesting that the system was saturated by carbachol stimulation. Muscarinic cholinergic receptors accessible to surface application at the rostral ventrolateral medulla antagonized by pirenzepine but not AF-DX 116 appear to be involved in the central chemoreceptor process.