Langerhans Cell Histiocytosis in an Adult - a rare, life-threatening and not to be missed.

Langerhans Cell Histiocytosis (LCH) is an uncommon neoplastic disorder characterized by accumulation of histiocytes in various tissues. The clinical manifestation is highly variable, ranging from an isolated skin rash or a single bony lesion, to fatal multi-organ failure. Due to its rarity and systemic involvement, the epidemiology of LCH is still not fully understood and most studies focus on the paediatric population. The extent of clinical involvement has important prognostic implications. Treatment options may be local or systemic depending on disease extent. Here we describe a rare case of adult onset LCH who presented with recurrent pneumothoraces, diabetes insipidus and papules and plaques over the scalp and forehead.

Microbial community of acetate utilizing denitrifiers in aerobic granules.

The aerobic sludge granules cultivated at high organic loading rates could effectively convert 100-700 mg l(-1) nitrite to nitrogen gas with 400 or 1,200 mg l(-1) dosed acetate. The denitrifying microbial community structure of the so-cultivated granules was investigated by 16S rRNA gene sequences and localized using fluorescence in situ hybridization (FISH). The 16S rRNA gene phylotypes in the clone library and FISH probes used exhibited high diversity among the bacteria and denitrifying communities, with the members of Betaproteobacteria predominant that were closely related to families Comamonadaceae, Nitrosomonadaceae, Alcaligenaceae, and Rhodocyclaceae. The confocal laser scanning microscope and staining test revealed that active microbial community principally distributed at 200-250 microm beneath the outer surface, embedded in extracellular polymeric substances.

Enhanced biological denitrification of high concentration of nitrite with supplementary carbon source.

Nitrite accumulates during biological denitrification processes when carbon sources are insufficient. Acetate, methanol, and ethanol were investigated as supplementary carbon sources in the nitrite denitrification process using biogranules. Without supplementary external electron donors (control), the biogranules degraded 200 mg l(-1) nitrite at a rate of 0.27 mg NO(2)-N g(-1) VSS h(-1). Notably, 1,500 mg l(-1) acetate and 700 mg l(-1) methanol or ethanol enhanced denitrification rates for 200 mg l(-1) nitrite at 2.07, 1.20, and 1.60 mg NO(2)-N g(-1) VSS h(-1), respectively; these rates were significantly higher than that of the control. The sodium dodecyl sulfate polyacrylamide gel electrophoresis of the nitrite reductase (NiR) enzyme identified three prominent bands with molecular weights of 37-41 kDa. A linear correlation existed between incremental denitrification rates and incremental activity of the NiR enzyme. The NiR enzyme activity was enhanced by the supplementary carbon sources, thereby increasing the nitrite denitrification rate. The capacity of supplementary carbon source on enhancing NiR enzyme activity follows: methanol > acetate > ethanol on molar basis or acetate > ethanol > methanol on an added weight basis.

Public awareness of hepatitis B infection: a population-based telephone survey in Hong Kong.

OBJECTIVE: To test our hypothesis that there is inadequate knowledge and awareness of hepatitis B infection among the general population in Hong Kong. DESIGN: A random telephone survey using a structured multiple-choice questionnaire. SETTING: Hong Kong community. PARTICIPANTS: Hong Kong residents aged 18 years or above. RESULTS: A total of 506 respondents were successfully interviewed in February 2010. Approximately half of respondents (55%) were aware that hepatitis B virus is the most common cause of chronic viral hepatitis in Hong Kong. Regarding knowledge about the mode of transmission, mother-to-infant transmission and blood contact were recognised as risk factors by 67% and 65% of respondents, respectively. Transmission by sexual contact, sharing a razor or toothbrush, and tattooing or body piercing were appreciated by 44%, 41%, and 37% of respondents, respectively. A majority (73%) had the mistaken belief that the virus is transmitted by eating contaminated seafood. Over half of respondents (53%) knew nothing about the clinical presentation of acute hepatitis B. Only 35% of respondents realised that periodic abdominal ultrasonographic examinations are indicated for asymptomatic hepatitis B carriers. While 51% of respondents reported being tested for hepatitis B virus infection, only 36% acknowledged being vaccinated against the infection. Education level, occupation, and marital status were factors associated with both hepatitis B virus screening and vaccination. CONCLUSION: These findings support our hypothesis that there is inadequate knowledge and awareness about hepatitis B infection in the general population in Hong Kong.

Disease progression in Chinese chronic hepatitis C patients with persistently normal alanine aminotransaminase levels.

BACKGROUND: Although chronic hepatitis C virus-infected patients with persistently normal alanine aminotransaminase levels usually have mild liver disease, disease progression can still occur. However, it is uncertain which group of patients is at risk of disease progression. AIM: To examine the severity of liver disease on liver biopsy in Chinese patients with persistently normal alanine aminotransaminase levels, and their disease progression over time. METHODS: Eighty-two patients with persistently normal alanine aminotransaminase levels were followed up longitudinally. The median time of follow-up was 8.1 years. Forty-seven of the 82 patients (57.3%) had a second liver biopsy. RESULTS: At the time of analysis, six of the 82 patients (7.3%) developed decompensated liver cirrhosis. Patients with an initial fibrosis stage F2 or F3 [6/23 (26.1%) vs. 0/59 (0%), P < 0.0001] or inflammatory grade A2 or A3 [5/40 (12.5%) vs. 1/42 (2.4%), P = 0.04] were more likely to develop decompensated liver cirrhosis. On multivariate analysis, initial fibrosis stage F2 or F3 was independently associated with progression to decompensated liver cirrhosis (relative risk 2.3, 95% confidence interval 0.03-2.5, P = 0.02). CONCLUSION: Chinese chronic hepatitis C virus patients with persistently normal alanine aminotransaminase levels with moderate to severe fibrosis at initial evaluation are more likely to develop decompensated liver cirrhosis.

Oxygen diffusion in active layer of aerobic granule with step change in surrounding oxygen levels.

High biomass density and large size limit the transfer of dissolved oxygen (DO) in aerobic granules. In the literature, the oxygen diffusivity is often employed as an input parameter for modeling transport processes in aerobic granules. The interior of an aerobic granule was observed to be highly heterogeneous. In this work, the distributions of extracellular polymeric substances (EPS) and cells in the interior of phenol-fed and acetate-fed granules were built up using a five-fold staining scheme, combined with the use of a confocal laser scanning microscope (CLSM). The steady-state and transient DO with step changes in surrounding DO levels at various depths were measured in the granules using microelectrodes. Cells were probed in a surface layer of thickness 125-375 microm. A marked fall in DO was also noted over this surface layer. No aerobic oxidation could occur beneath the active layer, indicating the oxygen transfer limit. Fitting the steady-state and transient DO data over the active surface layer yielded apparent diffusivities of oxygen were (9.5+/-3.5)x10(-10)m(2)s(-1) for the phenol-fed granule and (3.5+/-1.0)x10(-10)m(2)s(-1) for the phenol-fed granule. These values were lower than those adopted in models in the literature.

Multiplexed PCR genotyping of HPVs from plantaris verrucae.

BACKGROUND: Plantaris verrucae are a common diagnosis in childhood, consume a significant amount of health-care resources, have many painful treatment options and many recurrences. OBJECTIVES: The objective of this study was to design and test a single site-anchored, multiplexed and expandable PCR assay for common types of cutaneous HPVs. STUDY DESIGN: Common forward and unique reverse primers were selected from the E2 open reading frames of five cutaneous HPV genotypes. These were analyzed for sensitivity and selectivity using pHPV plasmids and several control DNAs in an optimized multiplexed assay. This standardized assay was used to analyze human verruca plantaris tissue for genome type and to evaluate the effect of a commonly used treatment protocol. RESULTS: A sensitive, multiplexed PCR assay for human cutaneous HPV genotypes 1a, 2a and 4 was developed. Specific-unique primers and a consensus anchor primer were selected within the HPV E2 region to produce amplicons varying by greater than 100bp. In analytical sensitivity studies, fewer than 100 genome copies of HPV1a and 2a were detected, and fewer than 1000 copies of HPV4 were detected. The multiplexed assay did not amplify regions of human placenta, calf thymus, CaSki or SiHa DNA and E. coli, pBR322 or non-HPV virus DNAs. In combination with a forensic DNA extraction procedure, the multiplexed HPV assay detected and identified HPV types in 23 of 51 (45%) deep plantaris verrucae. Two patients were found with two different genotypes in single deep plantaris verruca. Detection of the HPV genome was followed as a function of tissue ablation and Mediplast treatment in one patient. In healing tissue, the genome content was reduced but had not totally disappeared. CONCLUSIONS: The multiplexed HPV assay can be used to determine genotype prevalence that may correlate with treatment efficacy.

Sequence and molecular analysis of the rpoA cluster genes from Xanthomonas campestris pv. campestris.

The Xanthomonas campestris rpsM (S13)-rpsK (S11)-rpsD (S4)-rpoA (alpha)-rplQ (L17) cluster, encoding RNA polymerase alpha-subunit and four ribosomal proteins, reside in a 3164-bp DNA region. The N-terminal sequence of the authentic alpha-protein determined chemically matches that predicted from the nucleotide sequence. rplQ is monocistronic, instead of being co-transcribed with the other genes as in Escherichia coli. Antiserum against the His-tagged alpha-protein cross-reacted with the E. coli alpha-protein.

Uptake of small liposomes by non-reticuloendothelial tissues.

The distribution of liposomes within the intravascular space and the extent to which they escape into extravascular space strongly impact on the application of lipid vesicles as a carrier for pharmacologically active agents. The present study investigates how intact small unilamellar vesicles (SUV) may be taken up by different tissues after intravenous injection into mice, using various types of SUV with different entrapped markers, lipid composition, size, doses of liposomal lipids and stability in the blood. Our focus was specifically on sphingomyelin (or distearoyl phosphatidylcholine)/cholesterol (2:1, mol/mol) SUV, which are known to be stable in the blood circulation. Our results indicated that, in addition to the reticuloendothelial tissues, intact SUV were taken up in several other parts of the body, including intestine, skin, carcass and legs. It appears that the accumulation of SUV in the intestine and the skin increases with time post-injection. Furthermore, from the kinetic data, the process of uptake of SUV by the skin and intestine is compatible with a non-saturable pathway, which follows first-order kinetics. This suggests that the cells involved in the uptake of SUV in the intestine and skin are not phagocytic cells, which are normally saturable.

Reactive atmospheric pressure plasma for highly efficient removal of structure-directing agents from zeolite thin films.

We present a novel approach to remove the structure-directing agent (SDA) from as-synthesized zeolites using an atmospheric pressure plasma jet (APPJ). This reduces the time required to less than 60 seconds as compared to the existing thermal calcination, whose durations range from hours to days. The highly reactive plasma also results in a pronounced Q(3)-to-Q(4) transformation in the pure-silica zeolite MFI.

Synthesis of diethylenetriaminepentaacetic acid conjugated inulin and utility for cellular uptake of liposomes.

The synthesis, binding of radioactive cations, liposomal encapsulation, and biodistribution of the oxidized-inulin reaction product with ethylenediamine and diethylenetriaminepentaacetic acid (4) are described. The four-step synthesis of the inulin derivative proceeded in a good overall yield of 72%. The complex of the inulin derivative with either 67Ga3+ or 111In3+ was stable in vivo and did not readily distribute into tissues, being excreted primarily in urine after intravenous administration to mice. The liposome-entrapped inulin derivative can be loaded with radioactive heavy metal cations by mobile ionophores in high radiochemical yields of 80-91%. Following the intravenous administration of the liposomal encapsulation of the indium-111-labeled inulin derivative, the entrapped compound had a biodistribution characteristic of liposomes and allowed an estimation of the extent of the intracellular uptake of liposomes. The ability of the inulin derivative to chelate many different types of metals will allow the use of this probe for studying subtle differences in tissue distribution resulting from different drug targeting or delivery protocols in the same animal by multiple labeling techniques. Moreover, the chelate-conjugated inulin permits studies of the applications of drug delivery systems in primates or human subjects by noninvasive techniques such as gamma-scintigraphic or nuclear magnetic resonance imaging methods.

Long-term follow-up after cure of Helicobacter pylori infection with 4 days of quadruple therapy.

BACKGROUND: We have shown that 4 days of quadruple therapy after omeprazole pre-treatment is an effective therapy for curing H. pylori infection. In this study we investigated whether this regimen would maintain the high cure rate during long-term follow-up. Some recent studies have reported high recurrence rates after apparent cure. Apparently not all methods to test for cure have sufficient sensitivity to pick up small numbers of residual bacteria. This study also served to investigate whether our methods to test for cure 5-6 weeks post-treatment were reliable. METHODS: All patients from a previous study were invited to return for a 14C-urea breath test and serology. A representative group of 37 patients (76%) returned for a urea breath test and serology. The mean follow-up was 14.7 months (range 11.4-23.6 months). RESULTS: None of the 37 patients had a positive urea breath test results. IgG antibody titres fell steadily in all patients, showing a mean decrease of 83% at the end of the follow-up. None of the patients showed an increase in titre. Reinfection was therefore 0% (0 of 37). CONCLUSION: Four days of quadruple therapy seems to be an effective therapy for the eradication of H. pylori as evidenced after long-term follow-up. Our biopsy methodology is reliable in identifying treatment failures 5-6 weeks post-treatment.

Composite poly(2-hydroxyethyl methacrylate) membranes as rate-controlling barriers for transdermal applications.

Composite membranes were prepared by casting a linear poly(2-hydroxyethyl methacrylate) (pHEMA) solution onto polyester non-woven supports, and then the supported pHEMA within the membranes was cross-linked by a diisocyanate cross-linking agent to form a network structure. The swelling and permeation properties of these membranes were evaluated, with a system of nitroglycerin and aqueous ethanol solution, for potential application in transdermal drug delivery. The degree of swelling of these membranes in water and aqueous ethanol decreases as the cross-linker content is increased and increases slightly with an increase in the original molecular weight of the linear pHEMA. The permeation rates of both nitroglycerin and ethanol increase as the cross-linker content is reduced, the polymer molecular weight increases, and the concentration of the casting solution or membrane thickness decreases. Depending on the preparation conditions, the membranes can be tailored to give a permeation flux ranging from 4 to 68 micrograms cm-2 h-1 for nitroglycerin.

Application of asymmetric TPX membranes to transdermal delivery of nitroglycerin.

In this study, asymmetric poly(4-methyl-1-pentene) (TPX) membranes, fabricated by the dry/wet inversion method, were applied to transdermal delivery of nitroglycerin (NTG), a drug for treating angina pectoris. The flux of NTG through the TPX membrane was measured in vitro by a Franz cell. The results indicate that the NTG flux through asymmetric TPX membranes is strongly dependent on the membrane structure, which can be varied by adding nonsolvents in the casting solution. By adding different kinds of nonsolvents and adjusting the added amounts, membranes with different NTG release rates can be fabricated. It was also found that, with suitable drug formula, the NTG dissolution rate of a prototype TPX patch is comparable to that of a commercial patch, Transderm-Nitro. In addition, the data of NTG flux through a composite of TPX membrane and pig skin are also presented.

Effect of lipid composition on insulin-mediated fusion of small unilamellar liposomes: a kinetic study.

Liposome-entrapped insulin could be used to prolong the hypoglycemic action of insulin. Also, the conjugation of insulin to the surface of liposomes allows the potential application of using insulin as a transporting molecule to deliver liposome-entrapped drugs to insulin-receptor rich tissues. The success of these two approaches of drug delivery depends on how insulin may interact with liposomes. The present study describes the application of the principle of kinetics to investigate the effect of insulin on the stability of various preparations of liposomal drug carriers. The technique of fluorescence resonance energy transfer was employed to study the destabilization of liposomal formulations through the process of insulin-mediated fusion of liposomes. The kinetics of insulin-mediated fusion appeared to be compatible with a model whereby the initial rate of fusion is governed by the mechanism of fusion of two small unilamellar, unfused liposomal particles. The rate constants of insulin-mediated fusion of various liposomal formulations were estimated from the initial rate of fusion, using the model of two-particle fusion. Arrhenius analysis of the rate constants of fusion at different temperatures suggests that the mechanism of insulin-mediated fusion of small unilamellar vesicles is not governed merely by the energy and frequency of collision between liposomal particles. Other factors, such as the binding of insulin with the surface of liposomes and the temperature effect on the dynamics of the liposomal membrane, as well as conformation of insulin, could potentially be important.(ABSTRACT TRUNCATED AT 250 WORDS)

Experience with distal circular myotomy for long-gap esophageal atresia.

From 1980 to 1994, the authors treated 65 cases of esophageal atresia (with or without tracheoesophageal fistula). Among these patients, 15 (23%) underwent pure proximal circular myotomies and five (8%) underwent both proximal and distal circular myotomies. Of the latter five cases, three were Gross type C and two were Gross type A. The gap ranged from 4.5 cm to 6.5 cm (mean, 5 cm). Surgical complications in these five patients included two anastomotic leaks (40%), one anastomotic stricture (20%), and four gastroesophageal refluxes (80%). Three patients eventually underwent fundoplication as an antireflux procedure. Mucosal outpouching was noted in all cases. The myotomy did not adversely affect the esophageal peristalsis and motility on the esophagogram. Esophageal function was similar to that of other children who had esophageal atresia without myotomy. All patients could eat food typical for their age. This limited experience suggests that distal circular myotomy might be a safe adjuvant procedure to achieve primary anastomosis in long-gap esophageal atresia.

Hapatitis A and E in Hong Kong.

Acute viral hepatitis is one of the most prevalent infectious diseases in Hong Kong and hepatitis A accounts for two thirds or more of reported cases. Improved sanitation has led to a decline in hepatitis A infection in childhood but more clinically overt adult cases now occur. Shellfish ingestion and recent travel are important risk factors. A highly immunogenic and effective inactivated hepatitis A vaccine is available. Hepatitis E is of emerging importance as a cause of acute hepatitis. Large outbreaks have occurred in China and other developing countries; sporadic cases occur in Hong Kong. High mortality is associated with hepatitis E complicating late pregnancy. Serological diagnosis by enzyme immunoassay for anti-HEV is available. The education of travellers to endemic areas is advised with special caution being given to pregnant women. A vaccine for hepatitis E is not yet available.

Acute viral hepatitis in Hong Kong: a study of recent incidences.

Acute hepatitis patients admitted to a referral centre from January 1995 through December 1995 were studied to determine the seroprevalence of the hepatitis viruses and related risk factors. Of the 434 patients with acute viral hepatitis, the episodes due to hepatitis A, B, C, D, and non-A, non-B, non-C, (non-ABC) were 214 (49.3%), 163 (37.6%), 7 (1.6%), 0 (0%), and 50 (11.5%), respectively. Acute hepatitis A and non-ABC hepatitis commonly occur in late spring and early summer and are probably related to the intake of shellfish and travel to endemic areas. Approximately 60% of cases of symptomatic hepatitis B infection were acute exacerbations of chronic infection. Sexual exposure was the single most important risk factor for acute hepatitis B infection. The rarity of acute hepatitis C and D might be related to the low rate of intravenous drug use in our locality. Hepatitis E virus probably contributed significantly to the cases of non-ABC hepatitis. Further studies are needed to establish the importance of various causative agents of acute hepatitis in Hong Kong.

Plesiomonas shigelloides infection in Hong Kong: retrospective study of 167 laboratory-confirmed cases.

OBJECTIVE: To study the epidemiological, clinical, and microbiological features of Plesiomonas shigelloides infection in Hong Kong. DESIGN: Retrospective study. SETTING: Infectious Disease Unit of a district hospital, Hong Kong. PATIENTS: Patients with laboratory-confirmed cases of Plesiomonas shigelloides infection between 1 January 1995 and 31 December 1998. MAIN OUTCOME MEASURES: Epidemiological and clinical data, antibiotic sensitivity, and clinical outcome. RESULTS: There was an increasing trend in the number of isolates of Plesiomonas shigelloides obtained and the prevalence of the bacterium. A total of 197 isolates were obtained from 188 patients, and most isolates (172; 87.3%) were obtained during the summer. Clinical and epidemiological data were available for 167 patients (85 males, 82 females). Patient age ranged from 1 month to 95 years; the mean and median ages of the patients older than 15 years were 51.0 and 40.5 years, respectively (n=132). Only 35 (21.0%) of the 167 patients had a history of travel outside Hong Kong, whereas 21 (12.6%) had a history of consuming seafood or uncooked food; 39 (23.4%) had underlying medical conditions. Most patients (165; 98.8%) had symptoms of Plesiomonas shigelloides infection. Nine (5.4%) patients had had chronic diarrhoea for more than 2 weeks; watery and bloody diarrhoea was discharged by 122 (73.1%) and 42 (25.1%) of the patients, respectively. All 197 Plesiomonas shigelloides isolates were sensitive to ofloxacin, or levofloxacin and ceftriaxone. Resistance or partial resistance was recorded for ampicillin (72%), tetracycline (67%), co-trimoxazole (12%), and chloramphenicol (5%). The majority of patients (142/167; 85.0%) had self-limiting cases of infection, but 25 patients were given antibiotics for more severe symptoms at the time of presentation; there were two deaths. CONCLUSIONS: The occurrence of Plesiomonas shigelloides infection in Hong Kong is increasing, although most cases of are self-limiting.

Acute encephalitis complicating rubella.

During an epidemic of rubella in Hong Kong between October 1996 and June 1997, four male patients presented with rubella complicated by encephalitis, the symptoms of which started 1 to 5 days after the appearance of the rash characteristic of rubella. Two patients recovered completely within 1 week and one complained of a slight impairment of short-term memory. Severe cerebral oedema, and herniation across the brainstem and cerebellum developed in the fourth patient, who died 15 days later. The presence of serum immunoglobulin M antibody against rubella virus was demonstrated in all four patients; one patient also had immunoglobulin M antibody against rubella virus in his cerebrospinal fluid. No virus could be isolated during post-mortem examination of the fourth patient.