Dengue virus-associated hemophagocytic syndrome and dyserythropoiesis: a case report

A 33-year-old man had dengue hemorrhagic fever with initial presentation of fever, leukocytosis, and thrombocytopenia. The cause of the subsequent rapid decline in red cell counts without evidence of intravascular hemolysis or massive bleeding was confirmed as hemophagocytosis and dyserythropoiesis by bone marrow study. The patient recovered with supportive care and the bone marrow pattern was normal on repeated bone marrow study. To our knowledge, this is the first reported case of dengue virus-associated hemophagocytosis and dyserythropoiesis in Taiwan. Clinicians should consider that the occurrence of hemophagocytosis and dyserythropoiesis could be due to dengue virus infection. That this dengue virus infection was confirmed by a positive serology result at the convalescent stage but not at the acute symptomatic stage underlines the need for a second dengue serology study, as dengue infection can be missed due to an initial negative serology result.     

Ileocolic free flap reconstruction, concomitant chemotherapy and radiotherapy and assessment of speech and swallowing function during management of advanced cancer of the larynx and hypopharynx: preliminary report

CONCLUSION: The new technique of ileocolic free flap reconstruction provides a better quality of life in terms of swallowing and speech for patients who have undergone laryngopharyngectomy with concomitant chemotherapy and radiotherapy (CCRT). OBJECTIVES: To compare and contrast the swallowing and speech outcomes of patients who underwent total laryngopharyngectomy with ileocolic free flap reconstruction and to analyze the survival rate after surgery and CCRT. MATERIAL AND METHODS: This was a follow-up study of 12 patients with advanced (stages III, IVA and IVB) laryngeal and hypopharyngeal cancer who underwent major surgery, CCRT (with one exception) and ileocolic free flap reconstruction. RESULTS: All patients were able to tolerate single-stage combined management comprising total laryngopharyngectomy with or without radical neck dissection plus ileocolic free flap reconstruction and postoperative CCRT (with one exception), without immediate morbidity or mortality. Eleven patients were diagnosed with hypopharyngeal cancer and one with laryngeal cancer. The mean interval between surgery and CCRT was 34.1 days. The mean follow-up period was 16.5 months. Four patients died during the follow-up period as a result of local recurrence (n=2), distant metastasis (n=1) and suicide (n=1). One patient was alive with disease despite neck recurrence.     

Vibratory adaptation of cutaneous mechanoreceptive afferents

The objective of this study was to investigate the effects of extended suprathreshold vibratory stimulation on the sensitivity of slowly adapting type 1 (SA1), rapidly adapting (RA), and Pacinian (PC) afferents. To that end, an algorithm was developed to track afferent absolute (I0) and entrainment (I1) thresholds as they change over time. We recorded afferent responses to periliminal vibratory test stimuli, which were interleaved with intense vibratory conditioning stimuli during the adaptation period of each experimental run. From these measurements, the algorithm allowed us to infer changes in the afferents' sensitivity. We investigated the stimulus parameters that affect adaptation by assessing the degree to which adaptation depends on the amplitude and frequency of the adapting stimulus. For all three afferent types, I0 and I1 increased with increasing adaptation frequency and amplitude. The degree of adaptation seems to be independent of the firing rate evoked in the afferent by the conditioning stimulus. In the analysis, we distinguished between additive adaptation (in which I0 and I1 shift equally) and multiplicative effects (in which the ratio I1/I0 remains constant). RA threshold shifts are almost perfectly additive. SA1 threshold shifts are close to additive and far from multiplicative (I1 threshold shifts are twice the I0 shifts). PC shifts are more difficult to classify. We used an integrate-and-fire model to study the possible neural mechanisms. A change in transducer gain predicts a multiplicative change in I0 and I1 and is thus ruled out as a mechanism underlying SA1 and RA adaptation. A change in the resting action potential threshold predicts equal, additive change in I0 and I1 and thus accounts well for RA adaptation. A change in the degree of refractoriness during the relative refractory period predicts an additional change in I1 such as that observed for SA1 fibers. We infer that adaptation is caused by an increase in spiking thresholds produced by ion flow through transducer channels in the receptor membrane. In a companion paper, we describe the time-course of vibratory adaptation and recovery for SA1, RA, and PC fibers.     

Internal and surface subpopulations of the major surface protease (MSP) of Leishmania chagasi

Major surface protease (MSP) facilitates Leishmania promastigote evasion of complement-mediated lysis in the mammalian host and enhances host macrophage phagocytosis of the promastigotes. We previously showed that the steady-state abundance of MSP protein increases 14-fold during in vitro cultivation of L. chagasi promastigotes from logarithmic to stationary phase, despite the fact that the total amount of MSP mRNA does not increase. Furthermore, 10 major MSP isoforms are differentially expressed in different promastigote growth phases, and attenuation of parasites by long-term in vitro cultivation influences MSP isoform expression. Herein, we report that although about two-thirds of newly synthesized MSP becomes surface localized, the rest of the MSP does not reach the promastigote surface. This internal MSP is stable without detectable decrease in abundance up to 6 days after biosynthesis. Furthermore, surface-localized MSP is released at different rates from logarithmic and stationary phase virulent Leishmania promastigotes. These data are consistent with the hypothesis that the major mechanism regulating MSP abundance is the rate of loss of surface-localized MSP from the promastigote surface, and that internally localized MSP is very stable.     

Inference of nested variance components in a longitudinal myopia intervention trial

This paper was motivated by a double-blind randomized clinical trial of myopia intervention. In addition to the primary goal of comparing treatment effects, we are concerned with the modelling of correlation that may come from two possible sources, one among the longitudinal observations and the other between measurements taken from both eyes per subject. The data are nested repeated measurements. We suggest three models for analysis. Each one expresses the correlation differently in various covariance structures. We articulate their differences and describe the implementations in estimation using commercial statistical software. The computer output can be further utilized to perform model selection with Schwarz criterion. Simulation studies are conducted to evaluate the performance under each model. Data of the myopia intervention trial are reanalysed with these models for illustration. The results indicate that atropine is more effective in reducing the progression rate, the rates are homogeneous across subjects, and, among the suggested models, the one with independent random effects of two eyes fits best. We conclude that model selection is a crucial step before making inference with estimates; otherwise the correlation may be attributed incorrectly to a different mechanism. The same conclusion applies to other variance components as well.     

Respiratory adenoviral infections in children: a study of hospitalized cases in southern Taiwan in 2001--2002

Adenoviruses account for 5-10 per cent of respiratory illnesses in children. To analyse the clinical features and the temporal frequency in acute adenoviral respiratory infections in hospitalized children in southern Taiwan, a total of 4333 children who were admitted to the Department of Pediatrics, Kaohsiung Municipal Hsiaokang (KMHK) Hospital, with clinical evidences of acute respiratory infections between January 2001 and December 2002 were studied. Adenoviruses were isolated from 317 patients with an isolation rate of 7.67 per cent. Serotype analysis was performed by polymerase chain reaction (PCR) and/or PCR-restriction fragment length polymorphism (PCR-RFLP) in 186 specimens. In 2001, adenovirus type 4 was found in the majority (57 per cent), followed by type 1.5.6 (15 per cent), type 2 (13 per cent), type 14 (8 per cent), type 3 (5 per cent), and type 7 (2 per cent). In 2002, type 3 became the major type (46 per cent), whereas the previously predominant type 4 decreased to 6 per cent, and type 7 increased from 2 to 19 per cent. The symptoms and signs included fever (98.7 percent), cough (77.6 per cent), abnormal breathing sounds (crackles and/or wheezing 23.3 per cent), abdominal pain (18.9 per cent), vomiting (21.8 per cent), and diarrhea (25.2 per cent). The mean duration of fever was 4.8 days (range 0-19 days). In the 186 cases in whom serotypes were analysed, pharyngitis and tonsillitis (47.8 per cent) were the most common presentation, followed by pneumonia (25.2 per cent), bronchitis (12.9 per cent), and pharyngoconjunctival fever (PCF) (7.6 per cent). Children between 4 and 8 years old were the most common group of patients with respiratory adenoviral infections. Our patients all had good prognosis. This adenoviruses molecular epidemiological study provides information that helps physicians in clinical differential diagnosis and treatment of respiratory adenoviral infection in children in southern Taiwan.     

The characteristic features of muscle tension dysphonia before and after surgery in benign lesions of the vocal fold

Muscular tension dysphonia (MTD) is often concomitant in patients with underlying glottic insufficiency. It remains unclear, however, whether the characteristic features of MTD appear independently or as a consequence of dysphonia. We report here on a retrospective study of the prevalence of the four prominent characteristic features of MTD, as described by the Morrison-Rammage classification, in patients with benign lesions of the vocal fold. Two otorhinolaryngologists, independent of one another, rated the preoperative and postoperative videolaryngostroboscopic results of 260 patients to assess the presence or absence of MTD. Of the 260, 185 had vocal nodules, 49 had vocal polyp, and 26 had vocal cyst. Postoperative follow-up examinations were conducted for a period ranging from 4.5 to 35 months (mean = 18.5 months). Patient ages ranged from 18 to 76 years (mean = 47.3 years). Nearly 90% of the preoperative patients in our study cohort exhibited at least one of the MTD characteristic features. Approximately 74% of postoperative 'asymptomatic' patients in our study cohort exhibited at least one characteristic feature. As the characteristic features of MTD were found in both preoperative dysphonic patients and those patients who were successfully treated, MTD etiology may be causal (type I), concomitant (type IIa, IIb, III) or psychogenic (type IIa, IIb). Therefore characteristic features of MTD cannot be adequately resolved through surgery, and treatment should be supplemented by speech therapy to achieve the greatest effect in causal type I MTD.