Compartment-specific remodeling of splenic micro-architecture during experimental visceral leishmaniasis

Progressive splenomegaly is a hallmark of visceral leishmaniasis in humans, canids, and rodents. In experimental murine visceral leishmaniasis, splenomegaly is accompanied by pronounced changes in microarchitecture, including expansion of the red pulp vascular system, neovascularization of the white pulp, and remodeling of the stromal cell populations that define the B-cell and T-cell compartments. Here, we show that Ly6C/G(+) (Gr-1(+)) cells, including neutrophils and inflammatory monocytes, accumulate in the splenic red pulp during infection. Cell depletion using monoclonal antibody against either Ly6C/G(+) (Gr-1; RB6) or Ly6G(+) (1A8) cells increased parasite burden. In contrast, depletion of Ly6C/G(+) cells, but not Ly6G(+) cells, halted the progressive remodeling of Meca-32(+) and CD31(+) red pulp vasculature. Strikingly, neither treatment affected white pulp neovascularization or the remodeling of the fibroblastic reticular cell and follicular dendritic cell networks. These findings demonstrate a previously unrecognized compartment-dependent selectivity to the process of splenic vascular remodeling during experimental murine visceral leishmaniasis, attributable to Ly6C(+) inflammatory monocytes.     

Microduplication of Xp11.23p11.3 with effects on cognition,behavior, and craniofacial development

El‐Hattab AW, Bournat J, Eng PA, Wu JBS, Walker BA, Stankiewicz P, Cheung SW, Brown CW. Microduplication of Xp11.23p11.3 with effects on cognition, behavior, and craniofacial development. We report an ～1.3 Mb tandem duplication at Xp11.23p11.3 in an 11‐year‐old boy with pleasant personality, hyperactivity, learning and visual‐spatial difficulties, relative microcephaly, long face, stellate iris pattern, and periorbital fullness. This clinical presentation is milder and distinct from that of patients with partially overlapping Xp11.22p11.23 duplications which have been described in males and females with intellectual disability, language delay, autistic behaviors, and seizures. The duplicated region harbors three known X‐linked mental retardation genes: FTSJ1, ZNF81, and SYN1. Quantitative polymerase chain reaction from whole blood total RNA showed increased expression of three genes located in the duplicated region: EBP, WDR13, and ZNF81. Thus, over‐expression of genes in the interval may contribute to the observed phenotype. Many of the features seen in this patient are present in individuals with Williams‐Beuren syndrome (WBS). Interestingly, the SYN1 gene within the duplicated interval, as well as the STX1A gene, within the WBS critical region, co‐localize to presynaptic active zones, and play important roles in neurotransmitter release.     

Exploring the utility of whole‐exome sequencing as a diagnostic tool in a child with atypical episodic muscle weakness

The advent of whole‐exome next‐generation sequencing (WES) has been pivotal for the molecular characterization of Mendelian disease; however, the clinical applicability of WES has remained relatively unexplored. We describe our exploration of WES as a diagnostic tool in a 3½‐year old female patient with a 2‐year history of episodic muscle weakness and paroxysmal dystonia who presented following a previous extensive but unrevealing diagnostic work‐up. WES was performed on the proband and her two parents. Parental exome data was used to filter potential de novo genomic events in the proband and suspected variants were confirmed using di‐deoxy sequencing. WES revealed a de novo non‐synonymous mutation in exon 21 of the calcium channel gene CACNA1S that has been previously reported in a single patient as a rare cause of atypical hypokalemic periodic paralysis. This was unexpected, as the proband's original differential diagnosis had included hypokalemic periodic paralysis, but clinical and laboratory features were equivocal, and standard clinical molecular testing for hypokalemic periodic paralysis and related disorders was negative. This report highlights the potential diagnostic utility of WES in clinical practice, with implications for the approach to similar diagnostic dilemmas in the future.     

Investigation into the subambient behavior of aqueous mannitol solutions using temperature-controlled Raman microscopy.

The aim was twofold; to demonstrate the ability of temperature-controlled Raman microscopy (TRM) to locate mannitol within a frozen system and determine its form; to investigate the annealing behavior of mannitol solutions at -30 degrees C. The different polymorphic forms of anhydrous mannitol as well as the hemihydrate and amorphous form were prepared and characterized using crystal or powder X-ray diffractometry (XRD) as appropriate and Raman microscopy. Mannitol solutions (3% w/v) were cooled before annealing at -30 degrees C. TRM was used to map the frozen systems during annealing and was able to differentiate between the different forms of mannitol and revealed the location of both beta and delta polymorphic forms within the structure of the frozen material for the first time. TRM also confirmed that the crystalline mannitol is preferentially deposited at the edge of the frozen drop, forming a rim that thickens upon annealing. While there is no preference for one form initially, the study has revealed that the mannitol preferentially transforms to the beta form with time. TRM has enabled observation of spatially resolved behavior of mannitol during the annealing process for the first time. The technique has clear potential for studying other crystallization processes, with particular advantage for frozen systems.     

Evaluation of the PEP mask in cystic fibrosis

Twenty-eight patients suffering from cystic fibrosis, with an age range of 8-21 years entered a randomised cross-over trial to study the efficacy of the Positive Expiratory Pressure (PEP) mask as a method of chest physiotherapy, both on its own and in conjunction with other physiotherapy techniques. Twenty-four of these patients completed the trial consisting of 4 treatment programmes each lasting one month and with no wash-out period between them. Five of these patients went on to a fifth programme of Forced Expiratory Technique (FET) alone. At the end of the trial, no significant difference was found between the programmes as regards growth, Shwachman score, Chrispin-Norman score or pulmonary function tests. Twenty-three patients chose to continue using the PEP mask in conjunction with FET long-term as their chest physiotherapy programme as they felt it was an effective treatment allowing increased independence, with postural drainage being kept to a minimum.     

Word recognition functions for the CID W-22 test in multitalker noise for normally hearing and hearing-impaired subjects

Word recognition functions for Auditec recordings of the CID W-22 stimuli in multitalker noise were obtained using subjects with normal hearing and with mild-to-moderate sensorineural hearing loss. In the first experiment, word recognition functions were generated by varying the signal-to-noise ratio (S/N); whereas in the second experiment, a constant S/N was used and stimulus intensity was varied. The split-half reliability of word recognition scores for the normal-hearing and hearing-impaired groups revealed variability that agreed closely with predictions based on the simple binomial distribution. Therefore, the binomial model appears appropriate for estimating the variability of word recognition scores whether they are obtained in quiet or in a competing background noise. The reliability for threshold (50% point) revealed good stability. The slope of the recognition function was steeper for normal listeners than for the hearing-impaired subjects. Word recognition testing in noise can provide insight into the problems imposed by hearing loss, particularly when evaluating patients with mild hearing loss who exhibit no difficulties with conventional tests. Clinicians should employ a sufficient number of stimuli so that the test is adequately sensitive to differences among listening conditions.     

Reliability of threshold, slope, and PB max for monosyllabic words

The Auditec recordings of the CID W-22 monosyllables were used to generate test and retest intelligibility functions on normally hearing listeners and subjects with mild-to-moderate sensorineural hearing loss. The normally hearing subjects were tested with 50-word lists at SPLs ranging from 15 to 50 dB. Lists of 25 words were used with the hearing-impaired group. The functions were analyzed to assess the reliability of threshold (50% point), slope (20%-80% points), and maximum intelligibility (PB max). The 50% point was obtained at 28 dB SPL for the normally hearing listeners and at a sensation level (SL) of 12 dB respondaic thresholds for the hearing-impaired group. Very stable monosyllabic thresholds were found because 95% of the test-retest values were within 6 dB for both subject groups. Slopes of 4.9% per dB and 2.7% per dB were obtained for the normally hearing and hearing-impaired groups, respectively. Fair reliability was observed; 95% of the test-retest values encompassed a range of +/- 1.9% per dB for the normally hearing subjects and +/- 1.1% per dB for the hearing-impaired group. Although group slopes provide useful information for selecting the range and step size for generating psychometric functions, the value of routinely obtaining slope on an individual basis has not been demonstrated. Even though the same word lists were used for both test and retest measurements, reliability closely agreed with predicted results based on the binomial theorem. In contrast to the large variability for a single list of 25 words, very stable PB max scores were found when two or three scores were averaged on the plateau of the function.     

Latency and amplitude effects of electrode placement on the early auditory evoked response

This study examined the effects of electrode placement on the early auditory evoked response in normally hearing subjects. The electrodes are termed noninverting, inverting, and common. Ten commonly used electrode combinations were evaluated. Both amplitudes and latencies of Waves I, III, and V were measured for each electrode combination. No mean differences in latencies were observed for Waves I, III, or V with any of the 10 electrode combinations. Similarly, no statistically significant Wave I or Wave III amplitude differences were found among the 10 electrode montages. However, larger Wave V amplitudes were found with placement of the noninverting electrode at the vertex (0.53 mu v) as compared to the upper forehead (0.39 mu v). Moreover, Wave V amplitudes were larger for inverting/common electrode placements at the seventh cervical vertebra/forehead, neck/forehead, and neck/neck (approximately 0.50 mu v) than for mastoid/mastoid and mastoid/forehead placements (approximately 0.40 mu v). Thus, three combinations of electrodes gave the largest Wave V amplitudes. These placements for the noninverting, inverting, and common electrodes, respectively, were (a) vertex-seventh-forehead, (b) vertex-neck-forehead, and (c) vertex-neck-neck.