The first probe of a FLASH proton beam by PET

The recently observed FLASH effect related to high doses delivered with high rates has the potential to revolutionize radiation cancer therapy if promising results are confirmed and an underlying mechanism understood. Comprehensive measurements are essential to elucidate the phenomenon. We report the first-ever demonstration of measurements of successive in-spill and post-spill emissions of gammas arising from irradiations by a FLASH proton beam. A small positron emission tomography (PET) system was exposed in an ocular beam of the Proton Therapy Center at MD Anderson Cancer Center to view phantoms irradiated by 3.5 × 1010protons with a kinetic energy of 75.8 MeV delivered in 101.5 ms-long spills yielding a dose rate of 164 Gy s-1. Most in-spill events were due to prompt gammas. Reconstructed post-spill tomographic events, recorded for up to 20 min, yielded quantitative imaging and dosimetric information. These findings open a new and novel modality for imaging and monitoring of FLASH proton therapy exploiting in-spill prompt gamma imaging followed by post-spill PET imaging.

Third time's a charm: diagnosis of herpes simplex encephalitis after two negative polymerase chain reaction results

Introduction

Polymerase chain reaction (PCR) testing of cerebrospinal fluid (CSF) is a sensitive and specific method in diagnosing herpes simplex virus (HSV) encephalitis. However there are increasing reports of false negative HSV PCR.

Case description

We present a patient in the 9^th decade of life with abnormal behavior and focal seizures with MRI showing a right temporal T2 hyperintense non-enhancing lesion with electrographic evidence of right lateralized periodic discharges. CSF analysis and PCR for HSV-1 and 2 yielded negative results twice, and therefore acyclovir was discontinued. Patient initially improved following correction of hyponatremia. Patient however deteriorated and imaging revealed a new right parietal lesion. Third CSF sample showed lymphocytic pleocytosis with positive HSV-1 PCR. Patient improved following antiviral treatment.

Discussion

Acyclovir treatment should continue in high clinical suspicion scenarios despite negative HSV PCR. We further discuss causes of PCR false negatives and challenges it poses for patient care.

Electrodiagnostic studies in the intensive care unit: A comparison study 2 decades later

INTRODUCTION

Since the late 1980s, critical illness myopathy (CIM) and critical illness polyneuropathy (CIP) have been increasingly recognized in the intensive care unit (ICU). We explored whether these causes of ICU weakness were now more likely to lead to electrodiagnostic studies (EDX) at our institution than they were 19-20 years earlier.

METHODS

We reviewed 100 consecutive ICU patients who underwent EDX from 2009 to 2015 and compared them to a previously reported study population from 1990-1995.

RESULTS

Thirty-seven (39%) had CIM, CIP, or both versus 55% in the previous study (P = 0.04). Thirty-four (36%) were diagnosed with "traditional" pre-ICU causes of weakness, such as motor neuron disease or Guillain-Barre syndrome, versus 29% in the earlier study (P = 0.3).

DISCUSSION

CIM and CIP continue to be common disorders that lead to ICU EDX, but their proportion declined compared with 19-20 years earlier, possibly due to the perceived role and selective use of EDX in the ICU. Muscle Nerve 57: 772-776, 2018.

Study of commonly used organophosphate pesticides that induced oxidative stress and apoptosis in peripheral blood lymphocytes of rats

In a previous study, we have found that organophosphate (OP) pesticides such as chlorpyrifos (CPF), methyl parathion (MPT), and malathion (MLT) significantly induced genotoxicity in peripheral blood lymphocytes of rats. To explore the mechanism of OP-induced genotoxicity, we measured the formation of DNA interstrand cross-links (DICs) and apoptosis in peripheral blood lymphocytes of rats. Peripheral blood lymphocytes of rats were treated with CPF, MPT, and MLT individually and in combination at concentrations of 0.1 and 0.25 LC50 for 2, 4, 8, and 12 h at 37°C. Lipid peroxidation (LPO) was measured as a biomarker of oxidative stress. Apoptosis induced by CPF, MPT, and MLT individually and in combination was determined by measuring the intracellular level of active caspase-3 and caspase-9 by spectrofluorimetry. We found significant dose- and time-dependent increases in LPO, DICs formation and increase of intracellular active caspase-3 and caspase-9 in exposed peripheral blood lymphocytes of rats. These findings suggest that the studied pesticides have potential to induce oxidative stress, cause DNA adduct formation, and cause failure of adduct repair, which leads to apoptosis that is partially mediated by activation of intracellular caspase-3 and caspase-9.

Diseases in Disaster: Post-Earthquake Dermatoses, Nepal 2015

Nepal experienced a devastating earthquake measuring 7.8 Richter scale on 25th April 2015. Although the heightened effects were secondary to trauma, the indirect effects were also of prime importance. We came across different dermatoses, directly or indirectly secondary to earthquake. We here present an audit of the cutaneous effects following four months of the major shock presenting to a tertiary care center of central Nepal. A total of 7326 patients presented to the dermatology department over a period of four months following the major shock. Among them a total of 3833 patients (52.32%) had direct or indirect dermatoses following earthquake.

Abstract WP147: Advancing Rehabilitation in Ischemic Stroke Using Early Neurostimulants

Objective: To determine if the use of neurostimulant medications enables more patients with acute ischemic stroke to qualify for inpatient rehabilitation at hospital discharge.

Methods: Seventy-eight patients with ischemic stroke, admitted between 2011 and 2014 to an academic tertiary care stroke center, received neurostimulants during their admission and were retrospectively reviewed. A group of 78 controls from our institution’s stroke registry was matched 1:1 by sex, NIHSS, and age. The proportion of patients who were initially not candidates for an inpatient rehabilitation facility (IRF) but who subsequently became eligible, either after receiving neurostimulants or with standard care, was then compared between the two groups.

Results: There were 78 patients treated with neurostimulants, 46 of whom did not initially qualify for IRF; of these, 39.1% subsequently converted and qualified for IRF after initiating a neurostimulant medication. In comparison, only 12.5% of patients in the matched cohort converted after initially not qualifying for IRF (Fisher exact test, p=0.028). Mean time to initiation of neurostimulant was 5.5 days in patients who successfully converted to IRF status, compared to 7.3 days in those who did not (Student’s t-test, p=0.16).

Conclusions: In patients with acute ischemic stroke, early administration of neurostimulants may enable more to qualify for inpatient rehabilitation at hospital discharge.

Evaluation of genotoxic potential of commonly used organophosphate pesticides in peripheral blood lymphocytes of rats

Chlorpyrifos (CPF), methyl parathion (MPT), and malathion (MLT) are among the most extensively used organophosphate (OP) pesticides in India. DNA protein cross-links (DPC) and DNA strand breaks are toxic lesions associated with the mechanism(s) of toxicity of carcinogenic compounds. In the present study, we examined the hypothesis that individual and interactive genotoxic effects of CPF, MPT, and MLT are involved in the formation of DPC and DNA strand break. The DNA strand break was measured by comet assay and expressed as DNA damage index, while DPC estimation was carried out by fluorescence emission assay. The results showed that exposure of rat lymphocytes with CPF, MPT, and MLT caused significantly marked increase in DNA damage and DPC formation in time-dependent manner. MPT caused the highest damage, and these pesticides do not potentiate the toxicity of each other.

Evaluation of genotoxic potential of commonly used organophosphate pesticides in peripheral blood lymphocytes of rats

Chlorpyrifos (CPF), methyl parathion (MPT), and malathion (MLT) are among the most extensively used organophosphate (OP) pesticides in India. DNA protein cross-links (DPC) and DNA strand breaks are toxic lesions associated with the mechanism(s) of toxicity of carcinogenic compounds. In the present study, we examined the hypothesis that individual and interactive genotoxic effects of CPF, MPT, and MLT are involved in the formation of DPC and DNA strand break. The DNA strand break was measured by comet assay and expressed as DNA damage index, while DPC estimation was carried out by fluorescence emission assay. The results showed that exposure of rat lymphocytes with CPF, MPT, and MLT caused significantly marked increase in DNA damage and DPC formation in time-dependent manner. MPT caused the highest damage, and these pesticides do not potentiate the toxicity of each other.

Causes of stillbirths and neonatal deaths in Dhanusha district, Nepal: a verbal autopsy study

BACKGROUND

Perinatal (stillbirths and first week neonatal deaths) and neonatal (deaths in the first 4 weeks) mortality rates remain high in developing countries like Nepal. As most births and deaths occur in the community, an option to ascertain causes of death is to conduct verbal autopsy.

OBJECTIVE

The objective of this study was to classify and review the causes of stillbirths and neonatal deaths in Dhanusha district, Nepal.

MATERIALS AND METHODS

Births and neonatal deaths were identified prospectively in 60 village development committees of Dhanusha district. Families were interviewed at six weeks after delivery, using a structured questionnaire. Cause of death was assigned independently by two pediatricians according to a predefined algorithm; disagreement was resolved in discussion with a consultant neonatologist.

RESULTS

There were 25,982 deliveries in the 2 years from September 2006 to August 2008. Verbal autopsies were available for 601/813 stillbirths and 671/954 neonatal deaths. The perinatal mortality rate was 60 per 1000 births and the neonatal mortality rate 38 per 1000 live births. 84% of stillbirths were fresh and obstetric complications were the leading cause (67%). The three leading causes of neonatal death were birth asphyxia (37%), severe infection (30%) and prematurity or low birth weight (15%). Most infants were delivered at home (65%), 28% by relatives. Half of women received an injection (presumably an oxytocic) during home delivery to augment labour. Description of symptoms commensurate with birth asphyxia was commoner in the group of infants who died (41%) than in the surviving group (14%).

CONCLUSION

The current high rates of stillbirth and neonatal death in Dhanusha suggest that the quality of care provided during pregnancy and delivery remains sub-optimal. The high rates of stillbirth and asphyxial mortality imply that, while efforts to improve hygiene need to continue, intrapartum care is a priority. A second area for consideration is the need to reduce the uncontrolled use of oxytocic for augmentation of labour.

Comorbidities in pediatric patients with postural orthostatic tachycardia syndrome

OBJECTIVE

To investigate the frequency of various nonorthostatic complaints in children with postural orthostatic tachycardia syndrome (POTS).

STUDY DESIGN

We used our autonomic laboratory database to identify all pediatric patients with traditionally defined POTS who had completed the Ohio Dysautonomia Survey (ODYSA). The responses of the patients to questions targeting various autonomic complaints, including syncope, gastrointestinal symptoms, sleep disturbances, headaches, urinary symptoms, chronic pain, and Raynaud-like symptoms, were collected and analyzed.

RESULTS

A total of 53 pediatric patients completed the ODYSA questionnaire. The participants reported high frequencies of sleep abnormalities, chronic pain, Raynaud-like symptoms, and gastrointestinal abnormalities, with lower rates of headaches, syncope, and urinary complaints.

CONCLUSIONS

Our findings demonstrate the occurrence of various nonorthostatic symptoms in pediatric patients with POTS. These findings suggest the need for an interdisciplinary approach to the treatment and management of POTS, as well as for further investigation into the mechanisms that lead to the concurrent presentation of both orthostatic and nonorthostatic symptoms in these patients.

Ambient air quality monitoring during the H1N1 influence period in Pune (India)

Ambient air quality in an urban area is directly linked with activity level in the city including transport, business and industrial activities. Maharashtra Pollution Control Board (MPCB) has established an ambient air quality network in the city including state-of-the-art continuous air quality monitoring stations which indicate short duration air quality variations for criteria and non-criteria pollutants. The influence of H1N1 outbreak in Pune hitting its worst pandemic condition, led the civic authorities to implement stringent isolation measures including closure of schools, colleges, business malls, cinema halls, etc. Additionally, the fear of such a pandemic brought the city to a stand still. It was therefore necessary to assess the impacts of such activity level on ambient air quality in the city. It has been observed that such events have positive impacts on air quality of the city. There was a decrease in PM concentration almost to the tune of 30 to 40% if the impacts of precipitation, i.e. seasonal variations, are taken into account. Similarly, the non criteria pollutants too showed a marked but unusual decrease in their concentrations in this ever growing city. The influence of these in turn led to lowered concentrations of secondary pollutants, i.e. O3. Overall, the ambient air quality of Pune was found to be improved during the study period.

Orthostatic syndromes differ in syncope frequency

BACKGROUND

There are conflicting opinions on whether postural tachycardia syndrome predisposes to syncope. We investigated this relationship by comparing the frequency of syncope in postural tachycardia syndrome and orthostatic hypotension.

METHODS

We queried our autonomic laboratory database of 3700 patients. Orthostatic hypotension and postural tachycardia syndrome were defined in standard fashion, except that postural tachycardia syndrome required the presence of orthostatic symptoms and a further increase in heart rate beyond 10 minutes. Syncope was defined as an abrupt decrease in blood pressure and often, heart rate, requiring termination of the tilt study. Statistical analysis utilized Fisher's exact test and Student's t test, as appropriate.

RESULTS

Of 810 patients referred for postural tachycardia syndrome, 185 met criteria while another 328 patients had orthostatic hypotension. Of the postural tachycardia syndrome patients, 38% had syncope on head-up tilt, compared with only 22% of those with orthostatic hypotension (P<.0001). In the postural tachycardia group, syncope on head-up tilt was associated with a clinical history of syncope in 90%, whereas absence of syncope on head-up tilt was associated with a clinical history of syncope in 30% (P<.0001). In contrast, syncope on head-up tilt did not bear any relationship to clinical history of syncope in the orthostatic hypotension group (41% vs 36%; P=.49).

CONCLUSION

Our results demonstrate that syncope (both tilt table and clinical) occurs far more commonly in patients who have postural tachycardia syndrome than in patients with orthostatic hypotension. These findings suggest that one should be clinically aware of the high risk of syncope in patients with postural tachycardia syndrome, and the low-pressure baroreceptor system that is implicated in postural tachycardia syndrome might confer more sensitivity to syncope than the high pressure system implicated in orthostatic hypotension.

Primary small bowel malignancies: single-center results of three decades

We highlight one medical center's experiences with primary malignancies of the small bowel. During a 27-year period, 79 patients were treated for small bowel tumors. Of these, 15 (20%) were lost to follow-up; thus, 64 patients were reviewed retrospectively with emphasis on histological distribution and their topography, perioperative complications, overall survival, and prognostic factors. In our 64-patient series, 33 (51.6%) presented with adenocarcinoma; 10 (15.5%), lymphoma; 8 (12.1%), leiomyosarcoma; 5 (7.6%), neurogenic tumor; 2 (3%), unclassified carcinoma; 5 (7.6%), other types of sarcoma; and 1 patient presented with synchronous adenocarcinoma and lymphoma. Of all patients, 30 (46.9%) were curatively treated, whereas 34 (53.1%) underwent palliative procedures. Hospital lethality was 9.4% and mainly occurred in patients operated on under emergency circumstances. Reoperation rate was 29.7%. The observation period lasted at least five years or until death; three patients were alive less than five years postoperatively. Cumulative five-year survival rate was 22.5% in the adenocarcinoma group, 33.3% in the lymphoma group, 33.3% in the leiomyosarcoma group, and 22.2% in patients with other tumors. The uncharacteristic symptoms presented by patients suffering from small intestinal malignancies make early diagnosis difficult. Therefore, especially in patients with long-standing bowel diseases, malignancy should be considered. Early diagnosis and surgical treatment lead to a good prognosis as shown by our study.