Electrophysiological recordings in solitary photoreceptors from the retina of squid, Loligo pealei

A protocol was developed to isolate enzymatically photoreceptors from the retina of the squid, Loligo pealei. The procedure routinely results in a high yield of intact cells. Examination of solitary photoreceptors under Nomarski optics revealed that the fine morphological features described in anatomical studies of retinal sections are retained. The distal segment is up to 250 μm long, 4–7 μm wide, covered in part by short microvilli; the inner segment and the cell body, with the initial portion of the axon, are also clearly discernible in solitary cells. Suction electrode measurements performed from the cell body confirmed that responsiveness to light survived cell isolation. Macroscopic membrane currents were measured using the whole-cell tight-seal technique, and the perforated-patch method. Step depolarizations of membrane voltage administered in the dark elicited a slowly activating, sustained outward current. Light stimulation evoked an inward current graded with stimulus intensity; the peak current could amply exceed 1000 pA. Intense photostimulation gave rise to a prolonged inward aftercurrent that lasted for tens of seconds. On-cell patch recording along the intermediate segment and most of the smooth areas of the distal segment showed a large incidence of silent patches, with the occasional presence of voltage-dependent channels. On the other hand, channel activity could be recorded more frequently from electrode placements near the apical tip of the cell, where the presence of microvilli could be confirmed visually. Some patches were unresponsive to voltage Stimulation applied in the dark but produced distinct bursts of channel openings after illumination. The feasibility of single-cell electrophysiology in isolated photoreceptors, together with the growing body of biochemical information on cephalopod preparations, makes squid an attractive model system to investigate the visual process in invertebrates using multiple experimental approaches.

NT-ProBNP prediction of major chemotherapy-related toxicity and death in lymphoma patients

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Background: NT-Pro BNP provides diagnostic and prognostic information in many heart syndromes, but its role in oncologic patients is not established. Methods: We studied the association between NT-ProBNP levels and the risk of major toxicity associated with chemotherapy and death from all causes in 116 consecutive patients with lymphoma treated with curative intent. High resolution ultrasound echocardiography and serum NT-ProBNP levels were prospectively done previous the start of chemotherapy. Charlson Comorbidity Index was retrospectively calculated. A major toxicity event was defined as: when chemotherapy had to be discontinued, when chemotherapy had to be changed to a less intensive regimen, and treatment-related death. Results: High blood levels of NT-proBNP were associated with previous cardiologic history but not with left ventricular ejection fraction. With a median follow-up of 16 moths (0–49 months), 25 patients had a major toxic event with first line chemotherapy and 16 had died at last follow-up. The threshold of NT-ProBNP with better predictive accuracy for major toxicity-free and overall survival was 900 pg/mL. Patients with levels of NT-proBNP greater of 900 pg/mL had an adjusted hazard ratio (HR) for major toxicity after first-line chemotherapy for lymphoma of 6.4 (95%CI, 2.7–15.1). Two additional independent factors predicting higher major toxicity associated with chemotherapy were albumin < 3.5 g/mL (HR 3.5, P=0.008) and number of extranodal sites ≥ 2 (HR 3.1, P<0.007). For prediction of death from all causes, patients with a NT-ProBNP greater of 900 pg/mL had an HR of death of 15.3 (95%CI, 4.8–48.8; P<0.001). ECOG ≥ 2 was also significant for predicting death (HR 3.6; 95%CI, 1.1–11.6; P=0.03). The NT-Pro BNP added prognostic information beyond that provided by conventional risk factors, including IPI, left ventricular ejection fraction and Charlson comorbidity index. Conclusions: NT-ProBNP is the stronger marker for predicting major toxicity after first-line chemotherapy and death from all causes in patients with lymphoma and provides prognostic information beyond that provided by conventional lymphoma risk factors and comorbidity indexes.

No significant financial relationships to disclose.

[Erythrocyte removal from bone marrow by density gradient separation using the COBE 2991 cell processor with the triple-bag processing set]

ABO-incompatible bone marrow transplantation requires red blood cell depletion. Lots of laboratory adopted the technique of density gradient centrifugation (Ficoll-hypaque) using the COBE 2991 cell processor with simple-bag processing set. However, tubing of this set is not adapted to the currently available peristaltic pumps. Moreover, two other sets are required: one for the buffy-coat and one for postgradient cell washing. We developed a method using triple-bag processing set to conduct whole-step procedure (concentration, Ficoll and washing). Peristaltic PVC tubing is provided in one line of the set allowing a safe processing without several connections thus reducing risks of microbial contamination. First, we used buffy-coat of total blood for training, then, we carried out red cell depletion of healthy bone marrow donors. The red blood cell depletion was 97.9+/-1.1% and CD34+ recovery was 89.6+/-8.7%. These results are very close to those obtained with the simple-bag set (red cell depletion.=94.0+/-6.8% and CD34+ recovery=95.9+/-20.3%). We conclude that the triple-bag system, very little used in France, is practical, simplified the manipulation and is more safety than the simple-bag set.

An unusual case of vulval lump: tumour of anogenital mammary-like glands

We describe a 37-year-old woman who presented with a painless vulval lump of eight months duration. Excision biopsy revealed a benign lesion thought to be derived from mammary-like glands, which are well-documented in the anogenital region but under-recognized among genitourinary medicine practitioners. Our case highlights the importance of having a low threshold for biopsy of atypical vulval lesions.

Light-chain-restricted germinal centres in reactive lymphadenitis: report of eight cases

AIMS

Light-chain-restricted germinal centres are generally associated with the existence of a neoplastic lymphoproliferative disorder. The aim was to present a series of cases with persistent lymph node enlargement that featured some germinal centres showing light chain immunoglobulin restriction.

METHODS AND RESULTS

A series of six reactive lymphadenitis and two Castleman's disease cases was analysed by immunohistochemistry, IgH-polymerase chain reaction (PCR) and microdissected PCR. In all cases some germinal centres contained a population of plasma cells and plasmacytoid germinal centre cells showing light chain immunoglobulin restriction. In three cases the monotypic cells also showed distinct Bcl-2 expression. Two of the cases showed a predominant IgH rearrangement on a florid polyclonal background and one had an IgH monoclonal rearrangement, as revealed by PCR. Microdissected germinal centre PCR revealed a dominant repeated band in one of three cases and in another case a non-repeated clonal peak was observed. One of the patients developed a follicular lymphoma, which became evident from a subsequent biopsy.

CONCLUSIONS

These findings may be a manifestation of an underlying disorder in the regulation of the immune response, or an exaggeration of the germinal centre oligoclonal nature. This should be taken into account in the differential diagnosis of follicular hyperplasia.

Clinical utilization of near-infrared spectroscopy devices for burn depth assessment

The diagnosis of burn depth is based on a visual assessment and can be subjective. Near-infrared (NIR) spectroscopic devices were used preclinically with positive results. The purpose of this study was to test the devices in a clinical setting using easily identifiable burn wounds. Adult patients with acute superficial and full-thickness burns were enrolled. NIR point spectroscopy and imaging devices were used to collect hemodynamic data from the burn site and an adjacent unburned control site. Oxy-hemoglobin and deoxy-hemoglobin concentrations were extracted from spectroscopic data and reported as oxygen saturation and total hemoglobin. Sixteen patients (n=16) were included in the study with equal numbers in both burn wound groups. Point spectroscopy data showed an increase in oxygen saturation (p<0.0095) and total hemoglobin (<0.0001) in comparison with the respective control areas for superficial burn wounds. The opposite was true for full-thickness burns, which showed a decrease in oxygenation (p<0.0001) and total hemoglobin (p<0.0147) in comparison with control areas. NIR imaging technology provides an estimate of hemodynamic parameters and could easily distinguish superficial and full-thickness burn wounds. These results confirm that NIR devices can successfully distinguish superficial and full-thickness burn injuries.

Improved human T-cell responses against synthetic HLA-0201 analog peptides derived from the WT1 oncoprotein

Wilms tumor protein 1 (WT1) is a transcription factor overexpressed in several types of leukemia and solid tumors. For this reason, WT1 is an attractive target for immunotherapy. Four peptide nonamers from WT1 have been identified by others to generate a WT1-specific cytotoxic response in the context of human leukocyte antigen (HLA)-A0201 and A2402. However, as WT1 is a self-antigen, breaking tolerance is a potential obstacle to vaccination. Here, we use a strategy to circumvent tolerance by designing synthetic immunogenic analog peptides that could crossreact to the native peptides (a heteroclitic response). A number of synthetic peptides derived from nonamer sequences of the WT1 protein were designed in which single amino-acid substitutions were introduced at HLA-A0201 major histocompatibility complex (MHC)-binding positions. Several of new peptides could stabilize MHC class I A0201 molecules better than native sequences. Some analogs were also able to elicit WT1-specific T-cell recognition and cytotoxic T-cell lymphocytes more effectively than native sequences. Importantly, T cells stimulated with the new analogs crossreacted with the native WT1 peptide sequence and were able to kill HLA-matched chronic myeloid leukemia cell lines. In conclusion, analog heteroclitic WT1 peptides with increased immunogenicity can be synthesized and are potential cancer vaccine candidates.

Pilot trial of a synthetic breakpoint peptide vaccine in patients with chronic myeloid leukemia (CML) and minimal disease

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Background: CML is characterized by a tumor-specific fusion oncoprotein, BCR-ABL. Peptides spanning the B3A2 breakpoint of BCR-ABL can elicit MHC restricted T cell responses and clinical responses. No such data have previously been reported for vaccines targeting B2A2. Methods: We initiated a clinical trial administering synthetic analog breakpoint specific peptide vaccines for either B3A2 or B2A2 breakpoints to CML patients with major or complete cytogenetic remission. Measurable minimal disease was determined by either quantitative polymerase chain reaction (RQ-PCR) or nested PCR for BCR-ABL. Vaccine was administered with GM-CSF and Montanide ISA 51 subcutaneously. Eleven vaccinations were planned over the course of 1 year with the first 5 doses administered bi-weekly. Results: Eleven of 20 planned patients have been accrued to the study. Eight had documented cytogenetic remission and 3 were BCR-ABL positive via FISH analysis. Seven of the 11 patients had measurable BCR-ABL transcript levels as determined by RQ-PCR and all 11 were positive using the nested technique. Of the 5 patients positive for BCR-ABL (by RQ-PCR) before vaccination, 3 converted from RQ-PCR positive to negative while the transcript levels in the other patients decreased by approximately 1 log after 5 doses. All 5 of these patients remained positive using the nested PCR technique. Vaccination was well tolerated with local skin reactions at the injection sites. Immunologic reactivity was assessed ex vivo by CD4 autologous proliferation assay and T cell interferon (IFN) secretion (ELISPOT) assay. Ten of 11 patients were immunologically unreactive to the peptides prior to the vaccinations. Following the 5th dose of vaccine, 8/8 patients (including 2 with B2A2) tested showed significant immunologic responses by one of the above assays. Conclusions: These preliminary results suggest vaccination with synthetic analog peptides derived from CML proteins results in immunologic responses and may be associated with molecular improvement. Clinical efficacy of these vaccines in reducing/ eliminating minimal disease has yet to be established.

[Table: see text]

Long-term results for liver transplantation from non-heart-beating donors maintained with chest and abdominal compression-decompression

INTRODUCTION

The aim of this study was to evaluate long-term results after liver transplantation from non-heart-beating donors (NHBD) using the method of chest and abdominal compression-decompression to maintain donors.

METHODS

From December 1995 to November 2004, 10 NHBD were identified and maintained by means of the method of chest and abdominal compression-decompression until family and judicial permission were granted. Nine donors were Maastricht type II and one was type IV.

RESULTS

The mean age of donors was 40.5 years and the mean time under cardiopulmonary resuscitation (CPR) was 80 minutes. Orthotopic liver transplantation (OLT) was performed using these 10 liver grafts after a mean cold ischemia time of 561.5 minutes. All patients developed good posttransplant function, except for one patient who presented with primary nonfunction corrected with retransplantation. This complication was directly related to a long CPR time (P < .01). After a mean follow-up of 57 months, only one patient died from a hepatitis C virus (HCV) recurrence. The rest of the patients have maintained good graft function over time.

CONCLUSIONS

NHBD maintained with the method of chest and abdominal compression-decompression are a valid choice to increase the donor pool. Liver transplantation using these grafts has proven good long-term results, comparable to their heart-beating counterparts.

Fitness levels of middle aged martial art practitioners

OBJECTIVES

To quantify and compare fitness levels of middle aged practitioners of soo bahk do (SBD; a Korean martial art similar to karate) with those of sedentary subjects.

METHODS

Eighteen volunteers, 14 men and four women (aged 40-60 years), participated. Nine sedentary subjects (mean age 46.7 years) and nine SBD practitioners (mean age 46.8 years) were matched for sex and age. All subjects participated in a one day battery of fitness tests. The following dependent variables were tested: body composition, balance, flexibility, quadriceps strength, grip strength, muscle endurance, and aerobic capacity.

RESULTS

All dependent variables were analysed using paired t tests. Body composition (% body fat) for the SBD group was 18.9% v 30.8% for the sedentary group (p = 0.004). The SBD group was able to balance for 61.8 seconds v 26.2 seconds for the sedentary group (p = 0.02). The result for the sit and reach flexibility test was 22.3 cm for the SBD group v 10.4 cm for the sedentary group (p = 0.01). The number of push ups performed in one minute was 47.0 for the SBD group v 18.6 for the sedentary group (p = 0.0003), and the number of sit ups performed was 66.1 for the SBD group and 37.3 for the sedentary group (p = 0.00006). Aerobic capacity was 41.0 ml/kg/min v 31.1 ml/kg/min for the sedentary group (p = 0.04). Quadriceps strength was 99.5% (peak torque/body weight) v 83.0% for the sedentary group (p = 0.02). Only grip strength was not significantly different.

CONCLUSIONS

There were significant differences between the groups for most of the physical fitness tests. The SBD practitioners displayed greater aerobic capacity, balance, flexibility, muscle endurance, and strength, and less body fat than the sedentary controls matched for age and sex. SBD can be considered an excellent form of exercise for the promotion of fitness in adults. Health professionals should be aware that there are alternative methods to traditional exercise that can increase the physical fitness and health of the middle aged population.

Emergency department management of minor burn injuries in Ontario, Canada

Many thermal injuries are minor and can be effectively treated in a primary care setting. A cross-sectional survey was conducted to examine how emergency department physicians care for minor burns in the Canadian province of Ontario. Respondents were provided with a colour photograph of a patient with a minor burn and asked to comment about history, physical examination, investigations, treatment plan and follow-up care. A 37% response rate was attained (141/380). Of all respondents, 70% failed to record the burn extent, and 45% failed to discuss analgesia. No significant differences existed between emergency physicians in teaching and non-teaching hospitals (P > 0.05), with the exception that teaching hospital physicians referred significantly more to burn centres (P = 0.013). This suggests that educational interventions focussing on burn extent, pain control and referral criteria may be beneficial to emergency physicians.