Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Kikuchi-Fujimoto disease presenting as brainstem encephalitis with secondary blepharospasm

Central nervous system involvement in Kikuchi-Fujimoto disease is a very rare clinical manifestation. We report a 15-year-old girl who presented to us with fever, drowsiness, neck swellings, and involuntary closure of both eyelids of 2 days duration. Magnetic resonance imaging brain showed T2-weighted and fluid-attenuated inversion recovery hyperintensities in dorsal midbrain and pons. Cervical lymph node fine-needle aspiration cytology was suggestive of Kikuchi-Fujimoto disease. Blepharospasm secondary to infectious etiology is rare. Positron emission computed tomography brain showed increased focal uptake in anterior cingulate gyrus which can be the site of origin of blepharospasm. The patient was managed with steroids and trihexyphenidyl with significant recovery. Kikuchi-Fujimoto disease is a rare disease which has to be considered as one of the differential diagnosis in a case of acute encephalopathy with cervical lymphadenopathy

Quality of Sleep and Sleep Disorders in Patients with Parkinsonism: A Polysomnography Based Study from Rural South India

Objective: The objective of this study is to study the quality of sleep, sleep disorders, and polysomnographic profile in Parkinsonism patients from rural areas and to correlate polysomnographic profile with the staging of disease and with sleep questionnaire. Materials and Methods: Between May 2014 and December 2015, 168 Parkinsonism patients were prospectively screened using sleep questionnaire; Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), Parkinson Disease Sleep Score-2 (PDSS-2). Sixty patients underwent overnight polysomnography subsequently. Results: The mean age of 168 patients in the study was 65.3 ± 12.8 years. The mean duration of Parkinsonism was 4.6 ± 3.1 years. The mean ESS, PSQI and PDSS-2 were 12.4 ± 3.2, 7.9 ± 2.1 and 44.7 ± 5.8, respectively. A total of 148 patients (88.1%) had poor quality sleep, which was reported only in 37 patients (22%). Excessive daytime sleepiness (80%) and insomnia (76.7%) were most common symptoms. Polysomnographic profile showed poor sleep efficiency (median interquartile range [IQR] 74.8% [17.8%–99.5%]), reduced slow wave sleep (median [IQR] 0% [0%–9.5%]), and reduced rapid eye movement [REM] sleep (median (IQR) 4.9% [0.1%–24.2%]). Sleep disorders in the study were sleep fragmentation (n = 60, 100%), obstructive sleep apnea syndrome (n = 40, 66.7%), central sleep apnea syndrome (n = 6, 10%), and periodic limb movement disorder (n = 52, 86.7%). Two patients had REM sleep behavioral disorder clinically. There was statistically significant positive correlation between staging of disease, sleep latencies, and sleep questionnaire. Conclusion: Sleep is impaired in majority of Parkinsonism patients which needs to be diagnosed early and managed effectively. Patient education and awareness programs in rural areas regarding sleep disorders in Parkinsonism are required for early diagnosis

A Clinical and Electrophysiological Study of Peripheral Neuropathies in Predialysis Chronic Kidney Disease Patients and Relation of Severity of Peripheral Neuropathy with Degree of Renal Failure

Objective: To study the prevalence, clinical features, electrophysiological features, and severity of peripheral neuropathy in predialysis chronic kidney disease (CKD) patients with respect to severity of renal failure and presence of diabetes mellitus. Materials and Methods: Between May 2015 and December 2016, 200 predialysis CKD patients were assessed prospectively. Results: The prevalence of peripheral neuropathy in predialysis CKD patients in the present study was 45% based on clinical symptoms and 90% electrophysiologically. Mean age of 200 predialysis CKD patients who participated in the study was 53.2 ± 13.2 years. One hundred and thirty-six (68%) patients were male and 64 (32%) patients were female. Mean duration of disease was 2.2 ± 1.6 years. Nearly 45% patients of patients had asymptomatic peripheral neuropathy in the present study, which was more common in mild-to-moderate renal failure group. One hundred twenty-six patients (63%) had definite damage and 54 patients (27%) had early damage. In mild-to-moderate renal failure (n = 100) and severe renal failure patients (n = 100), 88% and 92% had significant peripheral neuropathy, respectively. Most common nerves involved were sural nerve, median sensory nerve, and ulnar sensory nerve. Diabetic patients (97%) showed more severe and high prevalence of peripheral neuropathy when compared to nondiabetic patients (83%). Most common patterns were pure axonal sensorimotor neuropathy and mixed sensorimotor neuropathy. Conclusion: Peripheral neuropathy is common in predialysis patients, prevalence and severity of which increases as renal failure worsens. Predialysis patients with diabetes show higher prevalence and severity of peripheral neuropathy when compared with nondiabetics

A clinical and electrophysiological study of peripheral neuropathies in peritoneal dialysis patients: Our experience from rural South India

The objective was to study the prevalence, clinical features, electrophysiological features, and severity of peripheral neuropathy in chronic kidney disease (CKD) patients on peritoneal dialysis (PD) and effect of the presence of diabetes mellitus (DM). Between May 2015 and December 2016, 100 CKD patients on PD were assessed. The prevalence of peripheral neuropathy was 65% based on clinical symptoms and 92% based on electrophysiological parameters. The mean age was 55.7 ± 10.9 years. About 64% were male. Twelve patients (12%) had motor weakness, 64 patients (64%) had positive symptoms and 60 patients (60%) had negative symptoms. Autonomic symptoms were seen in 14 patients (14%). Definite damage was seen in 68 patients (68%), early damage was seen in 16 patients (16%). In PD patients with DM (n = 50), 50 patients (100%) had definite damage. In PD patients without DM (n = 50), 18 patients (36%) had definite damage, 16 patients (32%) had early damage. In CKD patients on PD, patients aged >50 years (definite damage in 75.7%) showed more severe peripheral neuropathy when compared to patients aged ≤50 years (definite damage in 53%). Most common nerves involved in the present study were median motor nerve, sural nerve, ulnar sensory nerve, common peroneal nerve, posterior tibial nerve followed by the median sensory nerve. Peripheral neuropathy is common in CKD patients on PD, with higher prevalence and severity in elderly females and diabetics. Rationale management of diabetes in CKD patients on PD probably lowers the prevalence and severity of peripheral neuropathy