Antigenicity of the Leishmania infantum histones H2B and H4 during canine viscerocutaneous leishmaniasis

In this study we show that sera from dogs naturally infected with Leishmania infantum contain antibodies that specifically react against the parasite H2B and H4 histones. The Leishmania H2B and the amino-terminal region of the histone H4, expressed as fusion proteins, when confronted with sera from canine viscerocutaneous leishmaniasis (VCL) dogs, were recognized by 63% and 47%, respectively. No reactivity was detected when sera from dogs naturally infected with pathogens other than Leishmania were used. Using a collection of synthetic peptides covering the complete sequence of both proteins, we have determined that the main linear antigenic determinants are located in the amino-terminal domains of these histones. The humoral response against histones H2B and H4 induced during canine leishmaniasis was found to be specific for Leishmania histones, since no cross-reactivity of the VCL sera with mammal histones was observed. Also, a comparative study of the prevalence of antibodies among VCL sera against the four core histones of L. infantum was performed. Although a large heterogeneity of the humoral responses against these proteins was found, histones H2A and H3 seem to be more prevalent immunogens than histones H2B and H4 during canine natural leishmaniasis. The origin of the anti-histone humoral response and its possible implications in the pathogenesis of Leishmania infection are discussed.     

Severe childhood encephalopathy with dyskinesia and prolonged cognitive disturbances: evidence for anti‐N‐methyl‐d‐aspartate receptor encephalitis

Aim We report four cases of acquired severe encephalopathy with massive hyperkinesia, marked neurological and cognitive regression, sleep disturbance, prolonged mutism, and a remarkably delayed recovery (time to full recovery between 5 and 18mo) with an overall good outcome, and its association with anti‐N‐methyl‐d ‐aspartate (anti‐NMDA) receptor antibodies. Method We reviewed the four cases retrospectively and we also reviewed the literature. Results Anti‐NMDA receptor antibodies (without ovarian teratoma detected so far) were found in the two children tested in this study. Interpretation The clinical features are similar to those first reported in 1992 by Sebire et al., 1 and rarely recognized since. Sleep disturbance was not emphasized as part of the disorder, but appears to be an important feature, whereas coma is less certain and difficult to evaluate in this setting. The combination of symptoms, evolution (mainly seizures at onset), severity, paucity of abnormal laboratory findings, very slow recovery, and difficult management justify its recognition as a specific entity. The neuropathological substrate may be anatomically close to that involved in encephalitis lethargica, in which the same target functions (sleep and movement) are affected but in reverse, with hypersomnolence and bradykinesia. This syndrome closely resembles anti‐NMDA receptor encephalitis, which has been reported in adults and is often paraneoplastic.     

Hypothalamic osmoregulation is maintained across the wake–sleep cycle in the rat

In different species, rapid eye movement sleep (REMS) is characterized by a thermoregulatory impairment. It has been postulated that this impairment depends on a general insufficiency in the hypothalamic integration of autonomic function. This study aims to test this hypothesis by assessing the hypothalamic regulation of body fluid osmolality during the different wake–sleep states in the rat. Arginine‐vasopressin (AVP) plasma levels were determined following intracerebroventricular (ICV) infusions of artificial cerebrospinal fluid (aCSF), either isotonic or made hypertonic by the addition of NaCl at three different concentrations (125, 250 and 500 mm ). Animals were implanted with a cannula within a lateral cerebral ventricle for ICV infusions and with electrodes for the recording of the electroencephalogram. ICV infusions were made in different animals during Wake, REMS or non‐REM sleep (NREMS). The results show that ICV infusion of hypertonic aCSF during REMS induced an increase in AVP plasma levels that was not different from that observed during either Wake or NREMS. These results suggest that the thermoregulatory impairment that characterizes REMS does not depend on a general impairment in the hypothalamic control of body homeostasis.     

Simultaneous superficial hyperthermia and external radiotherapy: report of thermal dosimetry and tolerance to treatment

Background : In vitro and animal studies indicate that a moderate temperature of 41°C maintained for ～ 1h will provide radiosensitization if radiation (RT) and hyperthermia (HT) are delivered simultaneously, but not with sequential treatment. A minimum tumour temperature of 41°C is a more feasible goal than the goal of >42°C needed for sequential treatment. Methods and materials: Forty-four patients with 47 recurrent superficial cancers received simultaneous external beam radiotherapy and superficial hyperthermia on successive IRB approved phase I/II studies. All lesions had failed previous therapy, 35 were previously irradiated (mean dose 52.7Gy). Hyperthermia was delivered with 915MHz microwave or 1-3.5MHz ultrasound using commercially available applicators. The average dimensions of 19 lesions treated with microwave were 4.7 3.6 1.7cm and the average dimensions of 28 lesions treated with ultrasound were 8.0 6.1 2.9cm. The most common sites were chest wall (15 cases) and head and neck (21 cases). Temperatures were monitored at an average of six intratumoral locations using multisensor probes. The median number of hyperthermia treatments was three and the median radiation dose 30Gy. Radiation dose per fraction was 4Gy with hyperthermia and 2Gy or 4Gy (depending on protocol) on non-hyperthermia days. Results: Six different measures of minimum monitored temperature and duration were found to be highly correlated with each other. There was nearly a one-to-one correspondence between minimum tumour time at or above 41°C (Min t41) and minimum tumour Sapareto Dewey equivalent time at 42°C (Min teq42). After four sessions 63% of cases had a per session average Sapareto Dewey equivalent time at 41°C which exceeded 60min in all monitored tumour locations. The complete and partial response rate in evaluable lesions were respectively 21/41 (51% ) and 7/41 (17% ) and were best correlated with site (chest wall showing best response). Toxicity consisted of 10/47 (21% ) slow healing soft tissue ulcers which healed in all cases but required a median of 7 months. The most important predictors for chronic ulceration were cumulative radiation dose >80Gy and complete response to treatment. Conclusions: Minimum tumour temperatures maintained for durations compatible in vitro with thermal radiosensitization (if RT and HT are delivered simultaneously) are clinically feasible and tolerable for broad but superficial lesions amenable to externally applied ultrasound or microwave hyperthermia. The current in-house protocol is evaluating the impact of more than four hyperthermia sessions on the overall thermal dose distribution and toxicity.     

A type‐specific study of human papillomavirus prevalence in cervicovaginal samples in three different Spanish regions

Human papillomavirus (HPV) is the most frequent sexually transmitted viral infection. It is necessary to know HPV genotype distribution to identify how many women will be protected by HPV vaccines. During a period of 18 months, we have analyzed 2362 HPV positive reporting data from a secondary demand screening program in three regions in Spain (Cantabria, Leon and Burgos). The study has been conducted using polymerase chain reaction and tube array hybridization covering the 35 HPV genotypes described as affecting anogenital mucosa. There were no significant differences between the three regions according to genotype distribution. The most frequent were HPV16 (19.18%), HPV53 (11.26%) and HPV58 (7.66%). HPV18 was the source of 4.02% of infections. High‐risk HPVs were found in 1863/2362 cases. HPV16 was present in 24.3% of high‐risk infections and HPV18 was found in 5.1%. Uncommon genotypes (<5% of the total prevalence each) were found in 17,9% of the total high‐risk infections (334/1863). Multiple infections were diagnosed in 22% of the cases. The HPV genotype distribution is different from previously published data when multiple types are included in the screening. Both HPV16/18 account for 30% of high‐risk infections in a clinical setting in Spain. The presence of multiple genotypes is very common among the population.