The molecular diversity of dissolved organic matter in forest streams across central Canadian boreal watersheds

Small headwater streams can mobilize large amounts of terrestrially derived dissolved organic matter (DOM). While the molecular composition of DOM has important controls on biogeochemical cycles and carbon cycling, how stationary landscape metrics affect DOM composition is poorly understood, particularly in relation to non-stationary effects from hydrological changes across seasons. Here, we apply a combination of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and absorbance spectroscopy to characterize stream DOM from 13 diverse watersheds across the central Canadian boreal forests and statistically relate DOM compositional characteristics to landscape topography and hydrological metrics. We found that watershed runoff across different surface physiographies produced DOM with distinctly different chemical compositions related to runoff pH. Specifically, streams in sandy soil watersheds contained more abundant aromatic, nitrogenated and sulfurized fractions of DOM, likely due to a combination of lower soil capacity to absorb DOM than other soil types and high conifer forest coverage that generated acidic litterfall in more sandy watersheds. In contrast, streams with more neutral pH in watersheds with shallow soils had DOM resembling low oxidized phenolic molecules mainly due to increased brush/alder and deciduous vegetation coverage in relatively steeper watersheds. However, as precipitation and flows increased in the fall, the overall water chemistry of streams became more similar as runoff pH increased, the overall chemical diversity of DOM in streams decreased, and stream DOM resembled fresher, lower molecular weight lignin material likely originating from freshly produced leaf litter. Together, our findings show that during hydrologically disconnected periods, pH and landscape characteristics have important controls on the mobilization of aromatic DOM but that many landscape-specific characteristics in the Canadian boreal forest are less influential on DOM processing during wetter conditions where chemically similar, plant-derived DOM signatures are preferentially mobilized. These findings collectively help predict the composition of DOM across diverse watersheds in the Canadian boreal to inform microbial and contaminant biogeochemical processes in downstream ecosystems.

Mercury concentrations and export from small central Canadian boreal forest catchments before, during, and after forest harvest

Northern boreal forests are a strong sink for mercury (Hg), a global contaminant of significant concern to wildlife and human health. Mercury stored in forest soils can be mobilized via runoff and erosion, and under suitable conditions can be methylated to its much more bioaccumulative form, methylmercury. Forest harvesting can affect the mobilization and methylation of Hg, though the direction and magnitude of the impact is unclear or conflicting across previous studies. This study examined 5 harvested and 2 reference watersheds in northwestern Ontario, Canada, before, during, and after harvest to quantify changes in stream total and methylmercury concentration and loads and identified potential landscape and management factors that contribute to differences in stream response. In watersheds where streams were buffered by natural vegetation (≥30 m), no significant changes in total Hg or methylmercury concentrations or loads were observed. Significant increases in methylmercury concentrations and loads were observed downstream of a stream crossing in a watershed where the relatively small stream was unmapped and therefore only buffered by a 3 m machine exclusion zone. These results show that when current best management practices that minimize soil and water disturbance are followed, harvest can have a minimal impact on total and methylmercury loads, even in extensively harvested watersheds. However, there is a need for improved mapping of small streams to ensure best management practices are applied adequately across the landscape.

Benzodiazepine-Free Cardiac Anesthesia for Reduction of Postoperative Delirium (B-Free): A Protocol for a Multi-centre Randomized Cluster Crossover Trial

Delirium is common after cardiac surgery and is associated with adverse outcomes. Administration of benzodiazepines before and after cardiac surgery is associated with delirium; guidelines recommend minimizing their use. Benzodiazepine administration during cardiac surgery remains common because of its recognized benefits. The Benzodiazepine-Free Cardiac Anesthesia for Reduction of Postoperative Delirium (B-Free) trial is a randomized cluster crossover trial evaluating whether an institutional policy of restricting intraoperative benzodiazepine administration (ie, ≥ 90% of patients do not receive benzodiazepines during cardiac surgery), as compared with a policy of liberal intraoperative benzodiazepine administration (ie, ≥ 90% of patients receive ≥ 0.03 mg/kg midazolam equivalent), reduces delirium. Hospitals performing ≥ 250 cardiac surgeries a year are included if their cardiac anesthesia group agrees to apply both benzodiazepine policies per their randomization, and patients are assessed for postoperative delirium every 12 hours in routine clinical care. Hospitals apply the restricted or liberal benzodiazepine policy during 12 to 18 crossover periods of 4 weeks each. Randomization for all periods takes place in advance of site startup; sites are notified of their allocated policy during the last week of each crossover period. Policies are applied to all patients undergoing cardiac surgery during the trial period. The primary outcome is the incidence of delirium at up to 72 hours after surgery. The B-Free trial will enroll ≥ 18,000 patients undergoing cardiac surgery at 20 hospitals across North America. Delirium is common after cardiac surgery, and benzodiazepines are associated with the occurrence of delirium. The B-Free trial will determine whether an institutional policy restricting the administration of benzodiazepines during cardiac surgery reduces the incidence of delirium after cardiac surgery. Clinicaltrials.gov registration number: NCT03928236 (First registered April 26, 2019).

An unusual cause of oesophageal variceal bleeding in a Chinese human immunodeficiency virus-infected patient

Non-cirrhotic portal hypertension is an unusual but potentially serious liver disorder in human immunodeficiency virus-infected patients with prolonged exposure to didanosine. Due to its rarity, the diagnosis is often delayed. It is postulated that didanosine contributes to obliterative portal venopathy and causes portal hypertension. Affected patients may present with abnormal liver function or signs of portal hypertension, while the diagnosis usually depends on liver biopsy. We report a case of non-cirrhotic portal hypertension in a human immunodeficiency virus-infected patient. The reported histological features include nodular regenerative hyperplasia and hepatoportal sclerosis. Early recognition is important as timely management of severe portal hypertension may prevent potentially fatal gastro-intestinal bleeding.

Apoptosis, cytokine and chemokine induction by non-structural 1 (NS1) proteins encoded by different influenza subtypes

Background

Influenza pandemic remains a serious threat to human health. Viruses of avian origin, H5N1, H7N7 and H9N2, have repeatedly crossed the species barrier to infect humans. Recently, a novel strain originated from swine has evolved to a pandemic. This study aims at improving our understanding on the pathogenic mechanism of influenza viruses, in particular the role of non-structural (NS1) protein in inducing pro-inflammatory and apoptotic responses.

Methods

Human lung epithelial cells (NCI-H292) was used as an in-vitro model to study cytokine/chemokine production and apoptosis induced by transfection of NS1 mRNA encoded by seven infleunza subtypes (seasonal and pandemic H1, H2, H3, H5, H7, and H9), respectively.

Results

The results showed that CXCL-10/IP10 was most prominently induced (> 1000 folds) and IL-6 was slightly induced (< 10 folds) by all subtypes. A subtype-dependent pattern was observed for CCL-2/MCP-1, CCL3/MIP-1α, CCL-5/RANTES and CXCL-9/MIG; where induction by H5N1 was much higher than all other subtypes examined. All subtypes induced a similar temporal profile of apoptosis following transfection. The level of apoptosis induced by H5N1 was remarkably higher than all others. The cytokine/chemokine and apoptosis inducing ability of the 2009 pandemic H1N1 was similar to previous seasonal strains.

Conclusions

In conclusion, the NS1 protein encoded by H5N1 carries a remarkably different property as compared to other avian and human subtypes, and is one of the keys to its high pathogenicity. NCI-H292 cells system proves to be a good in-vitro model to delineate the property of NS1 proteins.

Profiles of cytokine and chemokine gene expression in human pulmonary epithelial cells induced by human and avian influenza viruses

Influenza pandemic remains a serious threat to human health. In this study, the repertoire of host cellular cytokine and chemokine responses to infections with highly pathogenic avian influenza H5N1, low pathogenicity avian influenza H9N2 and seasonal human influenza H1N1 were compared using an in vitro system based on human pulmonary epithelial cells. The results showed that H5N1 was more potent than H9N2 and H1N1 in inducing CXCL-10/IP-10, TNF-alpha and CCL-5/RANTES. The cytokine/chemokine profiles for H9N2, in general, resembled those of H1N1. Of interest, only H1N1, but none of the avian subtypes examined could induce a persistent elevation of the immune-regulatory cytokine - TGF-β2. The differential expression of cytokines/chemokines following infection with different influenza viruses could be a key determinant for clinical outcome. The potential of using these cytokines/chemokines as prognostic markers or targets of therapy is worth exploring.

Survey for the presence of BK, JC, KI, WU and Merkel cell polyomaviruses in human brain tissues

BACKGROUND

Recently three previously unknown polyomaviruses (KI, WU and Merkel cell polyomaviruses) have been identified from human specimens. The spectrum of clinical manifestations and their tissue tropism are currently unknown. Since a member of this virus family, JC virus, is well-known for its capacity to establish latency in human brain tissue where reactivation in immunocompromised individuals can result in fatal progressive multifocal leukoencephalopathy, we sought to examine for the presence of all the five known human polyomaviruses in a series of human brain tissues.

OBJECTIVES

To investigate the possibility of neuropersistence of the newly identified human polyomaviruses.

STUDY DESIGN

Autopsy brain tissues were collected from 10 different brain regions of 30 individuals who died from diseases unrelated to viral infections. Nested PCR was used to assess the presence or absence of viral DNA.

RESULTS

Ten samples collected from five individuals were found to harbour JCV DNA. In contrast, none of the 300 brain tissues examined showed positive results for BK, KI, WU or Merkel cell polyomavirus.

CONCLUSION

The newly identified KI, WU and Merkel cell polyomaviruses either do not, or have a much lower neuropersistent potential compared to JCV.

Identification of viral and atypical bacterial pathogens in children hospitalized with acute respiratory infections in Hong Kong by multiplex PCR assays

Acute respiratory tract infection is a leading cause of hospital admission of children. This study used a broad capture, rapid and sensitive method (multiplex PCR assay) to detect 20 different respiratory pathogens including influenza A subtypes H1, H3, and H5; influenza B; parainfluenza types 1, 2, 3, and 4; respiratory syncytial virus (RSV) groups A and B; adenoviruses; human rhinoviruses; enteroviruses; human metapneumoviruses; human coronaviruses OC43, 229E, and SARS-CoV; Chlamydophila pneumoniae; Legionella pneumophila; and Mycoplasma pneumoniae; from respiratory specimens of 475 children hospitalized over a 12-month period for acute respiratory tract infections. The overall positive rate (47%) was about twice higher than previous reports based on conventional methods. Influenza A, parainfluenza and RSV accounted for 51%, and non-cultivable viruses accounted for 30% of positive cases. Influenza A peaked at March and June. Influenza B was detected in January, February, and April. Parainfluenza was prevalent throughout the year except from April to June. Most RSV infections were found between February and September. Adenovirus had multiple peaks, whereas rhinovirus and coronavirus OC43 were detected mainly in winter and early spring. RSV infection was associated with bronchiolitis, and parainfluenza was associated with croup; otherwise the clinical manifestations were largely nonspecific. In general, children infected with influenza A, adenovirus and mixed viruses had higher temperatures. In view of the increasing concern about unexpected outbreaks of severe viral infections, a rapid multiplex PCR assay is a valuable tool to enhance the management of hospitalized patients, and for the surveillance for viral infections circulating in the community.

A cluster of chilblains in Hong Kong

OBJECTIVE

To report a recent clustering of chilblain cases in Hong Kong.

DESIGN

Case series.

SETTING

A regional hospital and a social hygiene clinic in the New Territories West, Hong Kong.

PATIENTS

Patients with a clinical diagnosis of chilblains in February 2008.

RESULTS

Eleven patients with chilblains were identified; seven (64%) gave an antecedent history of prolonged exposure to cold. They all presented with erythematous or dusky erythematous skin lesions affecting the distal extremities, especially fingers and toes. Laboratory tests revealed elevated antinuclear antibodies titres in two, positive rheumatoid factor in two, presence of cold agglutinins in one, and a raised anti-DNA titre (>300 IU/mL) in one. Skin biopsies were performed in six patients, four of them showed typical histopathological features of chilblains. In the patient with systemic lupus erythematosus, features of vasculitis were suspected, and in the one with pre-existing juvenile rheumatoid arthritis, there were features of livedo vasculitis. In 10 (91%) of the patients, the skin lesions had resolved when they were last assessed (at the end of March 2008), but had persisted in the patient who had pre-existing systemic lupus erythematosus.

CONCLUSION

The recent clustering of chilblains was possibly related temporally to the prolonged cold weather at the end of January to mid-February. In our series, most of the patients developed chilblains as an isolated condition and resolved spontaneously within a few weeks. Laboratory tests and skin biopsies for chilblains are not necessary, unless the condition persists, the diagnosis in doubt or an underlying systemic disease is suspected.

Rapid multiplex nested PCR for detection of respiratory viruses

Respiratory tract infections can be caused by a heterogeneous group of viruses and bacteria that produce similar clinical presentations. Specific diagnosis therefore relies on laboratory investigation. This study developed and evaluated five groups of multiplex nested PCR assays that could simultaneously detect 21 different respiratory pathogens: influenza A virus (H1N1, H3N2, and H5N1); influenza B virus; parainfluenza virus types 1, 2, 3, 4a, and 4b; respiratory syncytial virus A and B; human rhinoviruses; human enteroviruses; human coronaviruses OC43 and 229E; severe acute respiratory syndrome coronavirus; human metapneumoviruses; Mycoplasma pneumoniae; Chlamydophila pneumoniae; Legionella pneumophila; and adenoviruses (A to F). These multiplex nested PCRs adopted fast PCR technology. The high speed of fast PCR (within 35 min) greatly improved the efficiency of these assays. The results show that these multiplex nested PCR assays are specific and more sensitive (100- to 1,000-fold) than conventional methods. Among the 303 clinical specimens tested, the multiplex nested PCR achieved an overall positive rate of 48.5% (95% confidence interval [CI], 42.9 to 54.1%), which was significantly higher than that of virus isolation (20.1% [95% CI, 15.6 to 24.6%]) and that of direct detection by immunofluorescence assay (13.5% [95% CI, 9.7 to 17.4%]). The improved sensitivity was partly due to the higher sensitivity of multiplex nested PCR than that of conventional methods in detecting cultivatable viruses. Moreover, the ability of the multiplex nested PCR to detect noncultivatable viruses, particularly rhinoviruses, coronavirus OC43, and metapneumoviruses, contributed a major gain (15.6%) in the overall positive rate. In conclusion, rapid multiplex nested PCR assays can improve the diagnostic yield for respiratory infections to allow prompt interventive actions to be taken.

Inflammatory myofibroblastic tumor of the nasal cavity

Inflammatory myofibroblastic tumor (IMT) is a rare tumor with a variable natural history and biologic behavior, ranging from completely benign to malignant with fatal outcome. We report a case of benign IMT in the left nasal cavity with radiologic features mimicking angiofibroma. We also demonstrate the hypervascular nature of this disease on angiography and the contribution of preoperative embolization in assisting surgical excision and minimizing the potential uncontrolled intraoperative bleeding.

Kaposiform hemangioendothelioma: five patients with cutaneous lesion and long follow-up

Kaposiform hemangioendothelioma is a rare locally aggressive vascular tumor of the skin, deep soft tissue, and bone in children, characterized by infiltrating nodules and sheets of spindle cells, and unmistakable resemblance to Kaposi's sarcoma. More than 60 patients with such tumor have been reported so far, and while many have died as a result of extensive disease and severe coagulopathy, the long-term biologic behavior of this tumor remains undetermined. We describe five patients with kaposiform hemangioendothelioma and a mean follow-up of 19 years, ranging from 8 to 35 years. This report emphasizes on the importance of cutaneous lesions being the most commonly affected site, but also for its clinical diversity. Early diagnosis is possible even for a small skin lesion, which may be critical for the treatment of a potentially fatal deep-seated extensive tumor. All five patients are well, and three of them with persistent vascular tumor, which has carried two patients from childhood to adult. Although the behavior of this tumor might have been modified by radiation or interferon in three patients, this series indicates that kaposiform hemangioendothelioma is incapable of metastasis, despite a protracted course of many decades with no tendency for spontaneous regression.

Pathology of fatal human infection associated with avian influenza A H5N1 virus

Eighteen cases of human influenza A H5N1 infection were identified in Hong Kong from May to December 1997. Two of the six fatal cases had undergone a full post-mortem which showed reactive hemophagocytic syndrome as the most prominent feature. Other findings included organizing diffuse alveolar damage with interstitial fibrosis, extensive hepatic central lobular necrosis, acute renal tubular necrosis and lymphoid depletion. Elevation of soluble interleukin-2 receptor, interleukin-6 and interferon-gamma was demonstrated in both patients, whereas secondary bacterial pneumonia was not observed. Virus detection using isolation, reverse transcription-polymerase chain reaction and immunostaining were all negative. It is postulated that in fatal human infections with this avian subtype, initial virus replication in the respiratory tract triggers hypercytokinemia complicated by the reactive hemophagocytic syndrome. These findings suggest that the pathogenesis of influenza A H5N1 infection might be different from that of the usual human subtypes H1-H3.

Renal failure and cholestatic jaundice as unusual complications of childhood pustular psoriasis

Generalized pustular psoriasis (GPP) is uncommon in children, and serious renal and liver complications arising from GPP are rarely reported. We describe a Chinese boy who had suffered from recurrent exacerbations of GPP from the age of 1 year. He developed IgA nephropathy at the age of 9 years. He also had recurrent episodes of oliguric renal failure, hepatomegaly and cholestasis associated with severe exacerbations of GPP. These complications progressed despite early antibiotics and supportive therapy, but responded promptly to intravenous methylprednisolone therapy. Ultimately, acitretin was given and he has successfully been in remission for a year.

Burkitt's lymphoma presenting as mandibular swelling--report of a case and review of publications

Burkitt's lymphoma in a 4-year-old Chinese boy presented with acute mandibular swelling but no associated systemic disturbance. A review of published reports shows that the diagnosis should be suspected in jaw lesions with no obvious cause.

Reduced expression of APC and DCC gene protein in breast cancer

AIMS

To investigate if the adenomatous polyposis coli (APC) protein and the deleted in colorectal cancer (DCC) protein expression can be demonstrated by an immuno-histochemical method and to study the role of APC and DCC gene inactivation in the development and progression of breast cancer using colorectal cancer as a control model.

METHODS AND RESULTS

The reduced or loss of protein expression of the APC and DCC genes was studied in 27 surgical specimens of primary breast cancer using an immunohistochemical method. Reduced or lost expression was identified in 11 out of 27 samples (40.7%) for the APC gene and 15 out of 27 samples (55.6%) for the DCC gene. No statistically significant difference was observed between the reduced or lost protein expression and the histological grading of breast tumour for both the APC and the DCC gene.

CONCLUSIONS

Both gene proteins can be demonstrated by the immunohistochemical method. Reduced or loss of APC and DCC gene product were observed in 40.7% and 55.6% cases of primary breast cancer respectively. Further work is required to investigate the significance of the finding.

Porokeratotic eccrine ostial and dermal duct naevus with dermatomal trunk involvement: literature review and report on the efficacy of laser treatment

Porokeratotic eccrine ostial and dermal duct naevus (PEODDN) is a rare, benign hamartomatous malformation involving the eccrine sweat duct. The existence of filiform keratinous plugs that represent cornoid lamellae overlying dilated infundibula of eccrine ducts is a distinctive feature and the presence of associated abnormal dermal ducts is frequent. We report a patient with PEODDN who exhibited lesions on the left side of her chest. Cases of PEODDN reported in the literature are reviewed. Our experience in treating this patient with ultrapulsed carbon dioxide laser is also presented.

Herpes simplex virus type 2 infection in a 5-year-old boy presenting with recurrent chest wall vesicles and a possible history of herpes encephalitis

A 5-year-old hyperkinetic but otherwise healthy child presented with recurrent irritable vesicles and erosions of the anterior chest wall; they have been apparent since the age of 15 months. Wound swab cultures yielded herpes simplex virus type-2 (HSV-2) and Western blot serology showed past exposure to both HSV-1 and HSV-2. Skin biopsy results further supported a herpes virus infection. Magnetic resonance imaging of the brain showed right temporal lobe atrophy. An evaluation showed no evidence of sexual abuse in the patient but a Western blot assay of the mother's serum for HSV-2 was positive, while the father's was negative. In view of the diagnosis of HSV-2 infection in such a young patient, the possible routes of transmission and the time of acquisition of infection were explored. We believe the most likely route of infection in this child was postnatal, through intimate contact with the mother.

Isolation and characterization of a human heart cDNA encoding a new member of the small heat shock protein family--HSPL27

A novel cDNA clone was isolated from a human adult heart cDNA library. This cDNA clone is similar to the small heat shock protein (smhsp) in both DNA and amino acid sequences, especially in the conserved region. Sequence analysis has shown that the putative novel smhsp, named 27 kDa heat-shock-protein-like protein (HSPL27) is a protein of 241 amino acids with a deduced molecular mass of 26.7 kDa and a deduced pI of 8.0. We have expressed the HSPL27 in E. coli and the expressed protein was found to be present in the soluble fraction of the bacterial cell lysate. Chromosomal mapping data shows that the HSPL27 gene is located at human chromosome 5q11.2.

Late cosmetic results of short fractionation for breast conservation

BACKGROUND AND PURPOSE

The number of fractions of radiation therapy (RT) used after breast conserving surgery varies widely and accounts for a significant proportion of the workload in a modern radiotherapy department. Internationally, 'standard' therapy ranges from 3 to 7 weeks of daily treatment with or without a boost. Short RT schedules have the attraction of reducing workload but raise concern about an increased risk of late effects and poorer cosmetic outcome.

MATERIALS AND METHODS

In a randomized trial, 186 women with T1 or T2, pathologically node-negative breast cancer had cosmetic and various normal tissue effects data collected prospectively. The breast RT prescription was 44 Gy in 16 daily fractions to a tangent pair.

RESULTS

Median follow-up is 6.7 years. Actuarial 5-year breast recurrence was 6%. Overall cosmetic results at 5 years were good or excellent in 89% and 96% as reported by physicians and patients, respectively, and were stable between 2 and 5 years. Breast discomfort, erythema, edema and induration were related to both surgery and RT. At 5 years, 20% had breast discomfort, 18% had induration, 6% had erythema and 3% had some degree of breast edema. Fewer patients had these effects at 5 years than immediately after primary surgery. The presence of induration prior to starting RT was associated with a greater likelihood of breast induration 3 or more years following RT (P = 0.02). Thirteen percent of patients, generally those with large breasts, developed mild inframammary telangiectasia by 5 years.

CONCLUSIONS

Results are comparable to those reported from centers employing more conventional fractionation. Short fractionation produces acceptable cosmetic results for the majority of women if there are no contraindications to RT and in the absence of significant post-operative breast induration.

Effect of naturally occurring visual acuity differences between two eyes in stereoacuity

Stereoacuity was measured in 30 subjects with a naturally occurring visual acuity (VA) difference between the eyes. The stereoacuity was measured by a modified Howard's apparatus using the staircase method and VA was measured with log MAR charts. Stereoacuity was worse in subjects with a large VA difference between the two eyes; the correlation between stereoacuity and VA difference was significant (r = 0.76, P < 0.001). Neither the VA of the worse eye nor of the better eye contributed to the reduction in stereoacuity. The deterioration was more obvious if VA difference between the two eyes was one line or more (correlation coefficient, r= 0.88, P < 0.001). This study also reinforces the use of a > or = 70% stereothreshold when attempt stereoacuity results to compare with other studies.

A novel cDNA encoding a human homologue of ribosomal protein L29

During the large scale partial sequencing of human heart cDNA clones, a novel clone which is very similar to the rat ribosomal protein L29 in both DNA and amino acid sequences was found. The cDNA encodes a protein with a deduced molecular weight of 17751 (159 aa). It shows 80.4% homology to protein L29 from the large ribosomal subunit of rat and is related to yeast YL43. The putative protein was named human ribosomal protein L29 (hRPL29). hRPL29 has a large excess of basic residues over acidic ones. The large amount of charged residues makes the protein very hydrophilic and the protein has a deduced pI of 12.16. Internal repeats have been characterised in many ribosomal proteins and a tandem repeat of KAKAKAKA was found to be unique to hRPL29. Analysis of gene organisation by Southern blotting shows that of the approximate 10 copies of hrpL29, all but one are pseudogenes. Northern analysis indicated that the mRNA that encodes human L29 is approx. 800 base pairs in length. An intron of hrpL29 has also been cloned and sequenced by polymerase chain reaction using human genomic DNA as the template.

Analysis of expressed sequence tags from a fetal human heart cDNA library

Single-pass sequencing of randomly selected cDNA clones to generate expressed sequence tags (ESTs) has been widely used to identify novel genes and to study gene expression in a variety of tissues. We have generated 2244 ESTs from a human fetal heart library (GenBank Accession Nos. R30692-30774 and R56965-58824), which we present in this report. Of these, 51.7% showed no homology to known genes or were similar only to other ESTs, while 48.4% demonstrated homology to known transcripts. A total of 764 ESTs corresponding to known genes were used to study gene expression patterns in the fetal heart and to analyze differences in these patterns from those observed in the adult heart. These analyses demonstrate the utility of ESTs and sequence-tagged clones in comparative studies of gene expression in the cardiovascular system, and they reveal that differential gene expression underlies the structural and functional characteristics of the developing heart.

Cutaneous protothecosis: report of a case in Hong Kong

We report a patient who presented with recalcitrant ulcerated papules and plaques on both legs. Histopathology revealed protothecosis, and subsequent culture of the lesions grew Prototheca wickerhamii. Gradual resolution of the ulcers occurred on treatment with itraconazole.

Tufted angioma with complete regression

We describe 2 patients with tufted angioma (angioblastoma of Nakagawa) which regressed spontaneously. Both patients had a solitary but large lesion on the trunk. The 1st patient, a 3-month-old girl, presented with a 6-cm plaque which began to regress 2 years later. It regressed completely over 1 year and had not recurred after a further 6-year follow-up. The other patient, a 3-month-old boy, presented with a 12-cm mass of coalescent angiomatous papules which slowly regressed over 3-years, while small new lesions appeared in the adjacent contiguous skin. Eventually, gradual and near complete regression was observed after 8 years. The histology in both cases was typical, but bore some resemblance to the recently described kaposiform hemangioendothelioma, lobular capillary hemangioma and spindle cell hemangioendothelioma.

Cutaneous Rosai-Dorfman disease presenting as a suspicious breast mass

Cutaneous Rosai-Dorfman disease in a male patient presented as a clinically malignant left breast mass. The intra-operative frozen section indicated a benign inflammatory lesion and a simple excision was performed. The disease was apparently limited to the skin and subcutis of the left breast with no lymph nodes or other organs involvement. While the lesion demonstrated the characteristic morphology of Rosai-Dorfman disease, the diagnosis of granulomatous mastitis, epithelioid sarcoma and other cutaneous xanthohistiocytic proliferations were considered. In the absence of lymphadenopathy, a high index of diagnostic awareness is required to recognize the uncommon, solitary cutaneous Rosai-Dorfman disease.

Nodular fasciitis of the dermis

We describe the second reported patient with nodular fasciitis involving the dermis. Our case was morphologically a typical example of nodular fasciitis, but was distinctive by its cutaneous location and recurrence. As in the first reported case, the unexpected dermal involvement caused diagnostic difficulty, despite a typical histology.

Anaplastic large cell Ki-1 lymphoma of bone

Anaplastic large cell Ki-1 lymphoma is an uncommon type of non-Hodgkin's lymphoma that rarely presents primarily in the bone. Three such cases are reported. All patients were young and had bone pain; one had paraparesis as a complication of collapse of the thoracic vertebral body. The involvement was either monostotic or polyostotic. Radiologically, the lesions were lytic and had ill-defined borders. Histologically, the large neoplastic cells had pleomorphic bizarre nuclei, prominent nucleoli, abundant deeply amphophilic cytoplasm, and paranuclear pale hof. They were admixed with variable numbers of inflammatory cells. One case each was of T-cell, B-cell, and non-T non-B lineage. All three cases showed excellent responses to chemotherapy with or without radiation therapy. Recognizing the lymphomatous nature of this highly pleomorphic tumor is important because of its potential curability with appropriate chemotherapy.

Fatal haemoperitoneum as a result of liver metastases from nasopharyngeal cancer

Spontaneous rupture of hepatic metastases is rare, there being only 22 cases documented in the literature. We report here the first such case owing to nasopharyngeal carcinomatous metastases. This is of interest because in South East Asia ruptured hepatocellular carcinoma is the usual cause of fatal haemoperitoneum.

Fatal haemoperitoneum due to liver metastases from nasopharyngeal cancer

Spontaneous rupture of hepatic metastases is rare, there being only 22 cases documented in the literature. We report here the first such case due to nasopharyngeal carcinomatous metastases. This is of interest because in South East Asia ruptured hepatocellular carcinoma is the usual cause of spontaneous fatal haemoperitoneum.