Glioma-Immune Cell Crosstalk in Tumor Progression

Glioma progression is a complex process controlled by molecular factors that coordinate the crosstalk between tumor cells and components of the tumor microenvironment (TME). Among these, immune cells play a critical role in cancer survival and progression. The complex interplay between cancer cells and the immune TME influences the outcome of immunotherapy and other anti-cancer therapies. Here, we present an updated view of the pro- and anti-tumor activities of the main myeloid and lymphocyte cell populations in the glioma TME. We review the underlying mechanisms involved in crosstalk between cancer cells and immune cells that enable gliomas to evade the immune system and co-opt these cells for tumor growth. Lastly, we discuss the current and experimental therapeutic options being developed to revert the immunosuppressive activity of the glioma TME. Knowledge of the complex interplay that elapses between tumor and immune cells may help develop new combination treatments able to overcome tumor immune evasion mechanisms and enhance response to immunotherapies.

Neoadjuvant Chemotherapy with Laser Interstitial Thermal Therapy in Central Nervous System Neuroblastoma: Illustrative Case and Literature Review

Primitive neuroectodermal tumors of the central nervous system, or CNS neuroblastoma, are rare neoplasms in children. Recently, methylation profiling enabled the discovery of four distinct entities of these tumors. The current treatment paradigm involves surgical resection followed by chemotherapy and radiation. However, upfront surgical resection carries high surgical morbidity in this patient population due to their young age, tumor vascularity, and often deep location in the brain. We report a case of CNS neuroblastoma that can be successfully treated with neoadjuvant chemotherapy followed by minimally invasive laser interstitial thermal therapy and radiation. The patient has complete treatment with no evidence of recurrence at one year follow-up. This case illustrates a potential paradigm shift in the treatment of these rare tumors can be treated using minimally invasive surgical approach to achieve a favorable outcome.

PP2Ac Deficiency Enhances Tumor Immunogenicity by Activating STING-Type I Interferon Signaling in Glioblastoma

Glioblastoma (GBM) is an immunologically "cold" tumor that does not respond to current immunotherapy. Here, we demonstrate a fundamental role for the α-isoform of the catalytic subunit of protein phosphatase-2A (PP2Ac) in regulating glioma immunogenicity. Genetic ablation of PP2Ac in glioma cells enhanced double-stranded DNA (dsDNA) production and cGAS-type I IFN signaling, MHC-I expression, and tumor mutational burden. In coculture experiments, PP2Ac deficiency in glioma cells promoted dendritic cell (DC) cross-presentation and clonal expansion of CD8+ T cells. In vivo, PP2Ac depletion sensitized tumors to immune-checkpoint blockade and radiotherapy treatment. Single-cell analysis demonstrated that PP2Ac deficiency increased CD8+ T-cell, natural killer cell, and DC accumulation and reduced immunosuppressive tumor-associated macrophages. Furthermore, loss of PP2Ac increased IFN signaling in myeloid and tumor cells and reduced expression of a tumor gene signature associated with worse patient survival in The Cancer Genome Atlas. Collectively, this study establishes a novel role for PP2Ac in inhibiting dsDNA-cGAS-STING signaling to suppress antitumor immunity in glioma.

SIGNIFICANCE

PP2Ac deficiency promotes cGAS-STING signaling in glioma to induce a tumor-suppressive immune microenvironment, highlighting PP2Ac as a potential therapeutic target to enhance tumor immunogenicity and improve response to immunotherapy.

PP2Ac/STRN4 negatively regulates STING-type I IFN signaling in tumor-associated macrophages

Stimulator of IFN genes type I (STING-Type I) IFN signaling in myeloid cells plays a critical role in effective antitumor immune responses, but STING agonists as monotherapy have shown limited efficacy in clinical trials. The mechanisms that downregulate STING signaling are not fully understood. Here, we report that protein phosphatase 2A (PP2A), with its specific B regulatory subunit Striatin 4 (STRN4), negatively regulated STING-Type I IFN in macrophages. Mice with macrophage PP2A deficiency exhibited reduced tumor progression. The tumor microenvironment showed decreased immunosuppressive and increased IFN-activated macrophages and CD8+ T cells. Mechanistically, we demonstrated that Hippo kinase MST1/2 was required for STING activation. STING agonists induced dissociation of PP2A from MST1/2 in normal macrophages, but not in tumor conditioned macrophages. Furthermore, our data showed that STRN4 mediated PP2A binding to and dephosphorylation of Hippo kinase MST1/2, resulting in stabilization of YAP/TAZ to antagonize STING activation. In human patients with glioblastoma (GBM), YAP/TAZ was highly expressed in tumor-associated macrophages but not in nontumor macrophages. We also demonstrated that PP2A/STRN4 deficiency in macrophages reduced YAP/TAZ expression and sensitized tumor-conditioned macrophages to STING stimulation. In summary, we demonstrated that PP2A/STRN4-YAP/TAZ has, in our opinion, been an unappreciated mechanism that mediates immunosuppression in tumor-associated macrophages, and targeting the PP2A/STRN4-YAP/TAZ axis can sensitize tumors to immunotherapy.

New Developments in the Pathogenesis, Therapeutic Targeting, and Treatment of Pediatric Medulloblastoma

Pediatric medulloblastoma (MB) is the most common pediatric brain tumor with varying prognoses depending on the distinct molecular subtype. The four consensus subgroups are WNT, Sonic hedgehog (SHH), Group 3, and Group 4, which underpin the current 2021 WHO classification of MB. While the field of knowledge for treating this disease has significantly advanced over the past decade, a deeper understanding is still required to improve the clinical outcomes for pediatric patients, who are often vulnerable in ways that adult patients are not. Here, we discuss how recent insights into the pathogenesis of pediatric medulloblastoma have directed current and future research. This review highlights new developments in understanding the four molecular subtypes’ pathophysiology, epigenetics, and therapeutic targeting. In addition, we provide a focused discussion of recent developments in imaging, and in the surgery, chemotherapy, and radiotherapy of pediatric medulloblastoma. The article includes a brief explanation of healthcare costs associated with medulloblastoma treatment.

Effects of treatment processes on AOC removal and changes of bacterial diversity in a water treatment plant

The effectiveness of different treatment processes on assimilable organic carbon (AOC) removal and bacterial diversity variations was evaluated in a water treatment plant. The van der Kooij technique was applied for AOC analysis and responses of bacterial communities were characterized by the metagenomics assay. Results show that the AOC concentrations were about 93, 148, 43, 51, 37, and 38 μg acetate-C/L in effluents of raw water basin, preozonation, rapid sand filtration (RSF), ozonation, biofiltration [biological activated carbon (BAC) filtration], and chlorination (clear water), respectively. Increased AOC concentrations were observed after preozonation, ozonation, and chlorination units due to the production of biodegradable organic matters after the oxidation processes. Results indicate that the oxidation processes were the main causes of AOC formation, which resulted in significant increases in AOC concentrations (18-59% increment). The AOC removal efficiencies were 47, 28, and 60% in the RSF, biofiltration, and the whole system, respectively. RSF and biofiltration were responsible for the AOC treatment and both processes played key roles in AOC removal. Thus, both RSF and biofiltration processes would contribute to AOC treatment after oxidation. Sediments from the raw water basin and filter samples from RSF and BAC units were collected and analyzed for bacterial communities. Results from scanning electron microscope analysis indicate that bacterial colonization was observed in filter materials. This indicates that the surfaces of the filter materials were beneficial to bacterial growth and AOC removal via the adsorption and biodegradation mechanisms. Next generation sequencing analyses demonstrate that water treatment processes resulted in the changes of bacterial diversity and community profiles in filters of RSF and BAC. According to the findings of bacterial composition and interactions, the dominant bacterial phyla were Proteobacteria (41% in RSF and 56% in BAC) followed by Planctomycetes and Acidobacteria in RSF and BAC systems, which might affect the AOC biodegradation efficiency. Results would be useful in developing AOC treatment and management processes in water treatment plants.

Targeting Mitochondrial Oxidative Phosphorylation in Glioblastoma Therapy

As a multi-functional cellular organelle, mitochondrial metabolic reprogramming is well recognized as a hallmark of cancer. The center of mitochondrial metabolism is oxidative phosphorylation (OXPHOS), in which cells use enzymes to oxidize nutrients, thereby converting the chemical energy to the biological energy currency ATPs. OXPHOS also creates the mitochondrial membrane potential and serve as the driving force of other mitochondrial metabolic pathways and experiences significant reshape in the different stages of tumor progression. In this minireview, we reviewed the major mitochondrial pathways that are connected to OXPHOS and are affected in cancer cells. In addition, we summarized the function of novel bio-active molecules targeting mitochondrial metabolic processes such as OXPHOS, mitochondrial membrane potential and mitochondrial dynamics. These molecules exhibit intriguing preclinical and clinical results and have been proven to be promising antitumor candidates in recent studies.

MRI-guided laser interstitial thermal therapy using the Visualase system and Navigus frameless stereotaxy in an infant: technical case report

Laser interstitial thermal therapy (LITT) is increasingly used as a surgical option for the treatment of epilepsy. Placement of the laser fibers relies on stereotactic navigation with cranial fixation pins. In addition, the laser fiber is stabilized in the cranium during the ablation using a cranial bolt that assumes maturity of the skull. Therefore, younger infants (< 2 years of age) have traditionally not been considered as candidates for LITT. However, LITT is an appealing option for patients with familial epilepsy syndromes, such as tuberous sclerosis complex (TSC), due to the multiplicity of lesions and the likely need for multiple procedures. A 4-month-old infant with TSC presented with refractory focal seizures despite receiving escalating doses of 5 antiepileptic medications. Electrographic and clinical seizures occurred numerous times daily. Noninvasive evaluations, including MRI, magnetoencephalography, scalp EEG, and SPECT, localized the ictal onset to a left frontal cortical tuber in the premotor area. In this paper, the authors report a novel technique to overcome the challenges of performing LITT in an infant with an immature skull by repurposing the Navigus biopsy skull mount for stereotactic placement of a laser fiber using electromagnetic-based navigation. The patient underwent successful ablation of the tuber and remained seizure free 4 months postoperatively. To the authors' knowledge, this is the youngest reported patient to undergo LITT. A safe method is described to perform LITT in an infant using commonly available tools without dedicated instrumentation beyond standard stereotactic navigation, a biopsy platform, and the Visualase system.

Mitochondrial Dysfunction, Macrophage, and Microglia in Brain Cancer

Glioblastoma (GBM) is the most common malignant brain cancer. Increasing evidence suggests that mitochondrial dysfunction plays a key role in GBM progression as mitochondria is essential in regulating cell metabolism, oxidative stress, and cell death. Meanwhile, the immune microenvironment in GBM is predominated by tumor-associated macrophages and microglia (TAM), which is a heterogenous population of myeloid cells that, in general, create an immunosuppressive milieu to support tumor growth. However, subsets of TAMs can be pro-inflammatory and thereby antitumor. Therapeutic strategies targeting TAMs are increasingly explored as novel treatment strategies for GBM. The connection between mitochondrial dysfunction and TAMs phenotype in the tumor microenvironment is unclear. This review aims to provide perspectives and discuss possible molecular mechanisms mediating the interplay between glioma mitochondrial dysfunction and TAMs phenotype in shaping tumor immune microenvironment.

A comparison of the accuracy of fetal MRI and prenatal ultrasonography at predicting lesion level and perinatal motor outcome in patients with myelomeningocele

OBJECTIVE

Prenatal imaging has several critical roles in the diagnosis and management of myelomeningocele, including specific family counseling and the selection of fetal surgery or postnatal repair. In this study, the authors compared the accuracy of fetal MRI and prenatal ultrasonography (US) in predicting the spinal lesion level and assessed the correlation between imaging findings and motor function as independently evaluated by a physical therapist (PT) after birth.

METHODS

A retrospective review of demographic and clinical data was performed to identify children who had been treated with postnatal myelomeningocele closure at a single institution between March 2013 and December 2018. Patients were eligible for inclusion if they had all of the following: prenatal US identifying the neural tube defect level, fetal MRI identifying the neural tube defect level, and postoperative PT evaluation identifying the motor deficit level. Statistical analysis was performed using Cohen's kappa coefficient to compare the US- and MRI-demonstrated lesion level and correlate these findings with the motor level assigned postnatally by a PT via manual muscle testing.

RESULTS

Thirty-four patients met the inclusion criteria. The mean gestational age at US was 23.0 ± 4.7 weeks, whereas the mean gestational age at MRI was 24.0 ± 4.1 weeks. The mean time from surgery to the PT evaluation was 2.9 ± 1.9 days. Prenatal US and MRI were in agreement within one spinal level in 74% of cases (25/34, k = 0.43). When comparing the US-demonstrated spinal level with the PT-assigned motor level, the two were in agreement within one level in 65% of cases (22/34, k = 0.40). When comparing MRI-demonstrated spinal level with the PT motor level, the two were in agreement within one level in 59% of cases (20/34, k = 0.37). MRI and US were within two spinal levels of the PT evaluation in 79.4% and 85.3% of cases, respectively. MRI and US agreed within two levels in 97.1% of cases. Prenatal US and MRI were equivalent when comparing the difference between the imaged level and the postnatal motor deficit level (mean level difference: 1.12 ± 1.16 vs 1.17 ± 1.11, p = 0.86).

CONCLUSIONS

Prenatal US and MRI equivalently predicted the postnatal motor deficit level in children with myelomeningocele. These data may be valuable in prenatal prognostication.

Inhibition of protein phosphatase-2A with LB-100 enhances antitumor immunity against glioblastoma

PURPOSE

Glioblastoma (GBM) carries a dismal prognosis despite standard multimodal treatment with surgery, chemotherapy and radiation. Immune checkpoint inhibitors, such as PD1 blockade, for treatment of GBM failed to show clinical benefit. Rational combination strategies to overcome resistance of GBM to checkpoint monotherapy are needed to extend the promise of immunotherapy to GBM management. Emerging evidence suggests that protein phosphatase 2A (PP2A) plays a critical role in the signal transduction pathways of both adaptive and innate immune cells and that inhibition of PP2A could enhance cancer immunity. We investigated the use of a PP2A inhibitor, LB-100, to enhance antitumor efficacy of PD1 blockade in a syngeneic glioma model.

METHODS

C57BL/6 mice were implanted with murine glioma cell line GL261-luc or GL261-WT and randomized into 4 treatment arms: (i) control, (ii) LB-100, (iii) PD1 blockade and (iv) combination. Survival was assessed and detailed profiling of tumor infiltrating leukocytes was performed.

RESULTS

Dual PP2A and PD1 blockade significantly improved survival compared with monotherapy alone. Combination therapy resulted in complete regression of tumors in about 25% of mice. This effect was dependent on CD4 and CD8 T cells and cured mice established antigen-specific secondary protective immunity. Analysis of tumor lymphocytes demonstrated enhanced CD8 infiltration and effector function.

CONCLUSION

This is the first preclinical investigation of the effect of combining PP2A inhibition with PD1 blockade for GBM. This novel combination provided effective tumor immunotherapy and long-term survival in our animal GBM model.

Toward a comprehensive view of cancer immune responsiveness: a synopsis from the SITC workshop

Tumor immunology has changed the landscape of cancer treatment. Yet, not all patients benefit as cancer immune responsiveness (CIR) remains a limitation in a considerable proportion of cases. The multifactorial determinants of CIR include the genetic makeup of the patient, the genomic instability central to cancer development, the evolutionary emergence of cancer phenotypes under the influence of immune editing, and external modifiers such as demographics, environment, treatment potency, co-morbidities and cancer-independent alterations including immune homeostasis and polymorphisms in the major and minor histocompatibility molecules, cytokines, and chemokines. Based on the premise that cancer is fundamentally a disorder of the genes arising within a cell biologic process, whose deviations from normality determine the rules of engagement with the host's response, the Society for Immunotherapy of Cancer (SITC) convened a task force of experts from various disciplines including, immunology, oncology, biophysics, structural biology, molecular and cellular biology, genetics, and bioinformatics to address the complexity of CIR from a holistic view. The task force was launched by a workshop held in San Francisco on May 14-15, 2018 aimed at two preeminent goals: 1) to identify the fundamental questions related to CIR and 2) to create an interactive community of experts that could guide scientific and research priorities by forming a logical progression supported by multiple perspectives to uncover mechanisms of CIR. This workshop was a first step toward a second meeting where the focus would be to address the actionability of some of the questions identified by working groups. In this event, five working groups aimed at defining a path to test hypotheses according to their relevance to human cancer and identifying experimental models closest to human biology, which include: 1) Germline-Genetic, 2) Somatic-Genetic and 3) Genomic-Transcriptional contributions to CIR, 4) Determinant(s) of Immunogenic Cell Death that modulate CIR, and 5) Experimental Models that best represent CIR and its conversion to an immune responsive state. This manuscript summarizes the contributions from each group and should be considered as a first milestone in the path toward a more contemporary understanding of CIR. We appreciate that this effort is far from comprehensive and that other relevant aspects related to CIR such as the microbiome, the individual's recombined T cell and B cell receptors, and the metabolic status of cancer and immune cells were not fully included. These and other important factors will be included in future activities of the taskforce. The taskforce will focus on prioritization and specific actionable approach to answer the identified questions and implementing the collaborations in the follow-up workshop, which will be held in Houston on September 4-5, 2019.

Severe cranial deformity following cerebrospinal fluid diversion in an adolescent with osteogenesis imperfecta

Osteogenesis imperfecta (OI) is an inherited connective tissue disorder that causes bone fragility and deformity. Neurological manifestations, including macrocephaly and hydrocephalus, have been reported. Increased vascular fragility or bleeding diathesis also predisposes OI patients to intracranial hemorrhage. The development of chronic subdural fluid collections or hydrocephalus may require CSF diversion. The authors report a previously unrecognized complication of CSF diversion in a patient with OI, that is, a delayed severe cranial deformity, presumably due to over-shunting. In addition to the cosmetic concern, the deformity caused severe headaches and tenderness. The patient underwent craniectomy and titanium mesh cranioplasty, which resulted in the complete resolution of symptoms. This report raises the possibility that over-shunting in patients with OI could predispose to the formation of cranial deformity requiring surgical intervention.

Abstract LB-193: Protein phosphatase 2A inhibition,with a novel small molecule inhibitor, LB-100, achieves durable immune-mediated antitumor activity when combined with PD1 blockade in a preclinical model

LB-100 is a novel, first-in-class, small molecule inhibitor of protein phosphatase 2A (PP2A) recently shown in a Phase I trial to be well-tolerated at doses associated with stabilization of progressive solid tumors (Chung. Clin Cancer Res. 2017). PP2A has been implicated in mediating Akt signaling downstream of CTLA-4 (Parry. MolCell Biol. 2005). An in vivo pooled short hairpin RNA screen identified PP2A as a key regulator in suppressing T-cell proliferation in the tumor microenvironment (Zhou. Nature. 2014) and to be essential for regulatory-T-cell (Treg) function (Apostolidis. Nat Immunol. 2014). We hypothesized that pharmacologic inhibition of PP2A could enhance cancer immunity. We assessed the effect of LB-100 on T-cells in human allogenic mixed lymphocyte reactions, in which CD8+ or CD4+ T cells were co-cultured with monocyte-derived dendritic cells. We found a dose dependent increase in T cell proliferation in CD8+ and CD4+ cells and an increase in IFNγ secretion in CD4+ T cells. We investigated the effect of LB-100 plus anti-PD-1 antibody on CD4+ T cells in the same assay. The combination enhanced proliferation and IFNγ production compared to anti-PD-1 alone. For in vivo syngeneic studies, BALB/c mice were implanted subcutaneously in the right flank with CT26 colon carcinoma cells (5 x10^5 cells). 12 days after implantation, mice with tumors between 30-100 mm3 were randomized into four treatment groups (placebo, LB-100 - 0.16 mg/kg, anti-PD1- 10 mg/kg, and combination). Treatment was given every 2 days up to 28 days. 10 days after treatment, there was a significant decrease in tumor growth in the combination group compared to placebo or anti-PD-1 alone. 7/11 (63.6%) of mice treated with the combination and none in the other treatment groups achieved complete remission (CR). FACS analysis of the tumor infiltrating lymphocytes (TIL) after 10 days of treatment demonstrated enhanced IFNγ production in CD8+ T cells in the combination group compared to either treatment alone. There was also a marked decrease in FoxP3+ Treg cells in LB-100 treated group compared to placebo (3% vs 12% of CD4+ T cells, p&lt;0.05). Furthermore, mice achieving CR were resistant to tumor growth when re-inoculated with CT26 cells. Mice subjected to CD8+ T cell ablation using depleting antibodies, were unable to reject CT26 tumors - 0/8 (0%) despite treatment with combination therapy. This indicates that the anti-tumor effect of LB100 with anti-PD-1 treatment is CD8+ T cell mediated. In conclusion, we have shown in a syngeneic animal model that the PP2A inhibitor, LB-100, has synergistic potential in conjunction with checkpoint blockade supporting investigation of its ability to enhance immunotherapy in the clinic.

Citation Format: Winson S. Ho, Herui Wang, John S. Kovach, Rongze Lu, Zhengping Zhuang. Protein phosphatase 2A inhibition,with a novel small molecule inhibitor, LB-100, achieves durable immune-mediated antitumor activity when combined with PD1 blockade in a preclinical model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-193. doi:10.1158/1538-7445.AM2017-LB-193

In vitro cytotoxicity testing of a nanocrystalline silver dressing (Acticoat) on cultured keratinocytes

Acticoat is a polyethylene mesh coated with nanocrystalline silver. It has been used widely as a dressing for chronic wounds, acute partial-thickness burn wounds and donor sites. In this study, the in vitro cytotoxicity of Acticoat on cultured keratinocytes is tested. Human keratinocytes are cultivated on a pliable hyaluronate-derived membrane (Laserskin) using dermal fibroblasts as the feeder layer. When the cultured Laserskin (CLS) is subconfluent it is covered by Acticoat, which is exposed to water (Group 1), phosphate-buffered saline (Group 2) or culture medium (Group 3). The control group is not exposed to the Acticoat. After 30 minutes incubation at 37 degrees C, the inhibitory effect of the nanocrystalline silver on keratinocyte growth is measured by an MTT assay. Compared with the control, the relative viability of the CLS dropped to 0%, 0% and 9.3%, respectively. Thus, Acticoat is cytotoxic to cultured keratinocytes and should not be applied as a topical dressing on cultured skin grafts.

PP2A inhibition with LB100 enhances cisplatin cytotoxicity and overcomes cisplatin resistance in medulloblastoma cells

The protein phosphatase 2A (PP2A) inhibitor, LB100, has been shown in pre-clinical studies to be an effective chemo- and radio-sensitizer for treatment of various cancers. We investigated effects associated with LB100 treatment alone and in combination with cisplatin for medulloblastoma (MB) in vitro and in vivo in an intracranial xenograft model. We demonstrated that LB100 had a potent effect on MB cells. By itself, LB100 inhibited proliferation and induced significant apoptosis in a range of pediatric MB cell lines. It also attenuated MB cell migration, a pre-requirement for invasion. When used in combination, LB100 enhanced cisplatin-mediated cytotoxic effects. Cell viability in the presence of 1 uM cisplatin alone was 61% (DAOY), 100% (D341), and 58% (D283), but decreased with the addition of 2 μM of LB100 to 26% (DAOY), 67% (D341), and 27% (D283), (p < 0.005). LB100 suppressed phosphorylation of the STAT3 protein and several STAT3 downstream targets. Also, LB100 directly increased cisplatin uptake and overcame cisplatin-resistance in vitro. Finally, LB100 exhibited potent in vivo anti-neoplastic activity in combination with cisplatin in an intracranial xenograft model.

Berberine induces apoptosis via the mitochondrial pathway in liver cancer cells

Current chemotherapeutic strategies for liver cancer have limitations. Thus, the demand for complementary medicine is warranted. We evaluated the antitumor potential of berberine, a naturally bioactive phytochemical from Coptis chinensis Franch against Huh7 cancer cells and WRL68 liver cells. The antitumor activity of berberine was evaluated by flow cytometry. The caspase-dependent pathway was assessed using western blot analysis. Results showed that berberine induced the apoptosis of liver cancer cells through procaspase-9, and its effector caspases, procaspase-3 and procaspase-7. Flow cytometry revealed that berberine caused cell cycle arrest at the M/G1 phase. The results of reverse transcription-polymerase chain reaction showed that berberine increased the expression of Bax, which resulted in the activation of the caspase cascade. The present findings demonstrated that berberine induces the apoptosis of Huh7 cells via the mitochondrial pathway.

Abstract 505: Jagged 2 knockdown inhibits invasion in colorectal cancer cell lines

Background: The notch pathway is involved in control of cell differentiation in various tissues including pancreas, muscle and bone marrow. Jagged 2 (JAG2) is a ligand for the notch pathway and was found to be overexpressed in malignant plasma cells from patients with multiple myeloma, causing the secretion and release of IL-6, VEGF, and IGF-1 in the microenvironment supporting myeloma cell growth. In breast cancers, it was found to be overexpressed at the hypoxic invasive front and was significantly correlated with metastasis free survival. Furthermore, up-regulation of JAG2 expression in mouse lung adenocarcinoma cells promoted its metastasis in mice. However, the expression pattern and function of JAG2 in colorectal cancer (CRC) is not clear. Therefore in this study, we examined the expression of JAG2 in CRC cell lines and determined the effect(s) of JAG2 knockdown by RNA interference in CRC cell lines. Materials and Methods: The expression of JAG2 protein was examined in four CRC cell lines (SW480, SW620, HCT116, DLD-1) and also in 1 normal colon epithelial cell line (CCD18co) using the western blot. To investigate the effects JAG2 knockdown in CRC cell lines, a pool of 4 siRNAs against JAG2 was transfected into the 4 CRC cell lines listed above. The effects on cell growth was then determined by the CellTiter 96® AQueous One Solution Cell Proliferation Assay (the MTS assay) and the Matrigel invasion assay was performed to assess its effects on invasive capability. Results: Western blot results showed that JAG2 protein was expressed in all 4 colorectal cancer cell lines including SW480, SW620, HCT116 and DLD-1 but not in the CCD18co normal colon epithelial cell line. The MTS assay showed that cell growth was not affected by JAG2 knockdown in the CRC cell lines. Interestingly, the invasive capability of HCT116 and DLD-1cells was reduced after JAG2 knockdown. Conclusions: Results from this study suggest that JAG2 may play a role in the invasiveness of CRC cell lines but not in cell proliferation. JAG2 may be a promising therapeutic target for inhibition of metastasis in colorectal cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 505. doi:1538-7445.AM2012-505

BAG3-related myofibrillar myopathy in a Chinese family

In contrast to the usual slow disease progression in myofibrillar myopathies, patients with Bag3opathy often have a rapidly progressive and more severe phenotype with a worse prognosis. We describe a Chinese patient, born to non-consanguineous parents, who first presented at age 6 with clumsy walking and difficult climbing staircase. With a history of restrictive lung disease previously diagnosed as asthma, she progressed rapidly with proximal myopathy, rigid spine and bilateral tightening of the Achilles tendons requiring surgical elongation. Hypertrophic cardiomyopathy with restrictive physiology was shown by echocardiogram. Moreover, prolonged QT interval was also noted in the patient. Family history was unremarkable yet her father was incidentally found to have prolonged QT interval. Mutation analysis with genomic DNA of the proband showed heterozygous de novo known mutation c.626C>T (p.Pro209Leu) and a germline variation c.772C>T (p.Arg258Trp) in BAG3. Her father was found to be a carrier of c.772C>T. Muscle biopsy findings were suggestive of myofibrillar myopathy on light microscopy and ultrastructural studies. To our knowledge, this is the first Chinese case of Bag3opathy so far reported.

The Use of Pulsed Dye Laser for the Prevention and Treatment of Hypertrophic Scars in Chinese Persons

BACKGROUND

Pulse dye laser has been used with variable degrees of success in the treatment of hypertrophic scars, and although earlier reports suggested a significant degree of improvement, more recent studies have raised concern about its effectiveness. Furthermore, most previous studies examined its use in patients with light skin types, and the use of pulse dye laser in dark-skinned patients for the treatment of hypertrophic scars is not well established.

OBJECTIVE

The objective was to assess the role of pulsed dye laser therapy in the treatment and prevention of hypertrophic scars in Chinese persons.

METHODS

Twenty-nine patients (35 scars) who had scars for less than 6 months were recruited into the prevention group, and 27 patients (36 scars) who had scars for more than 6 months were recruited into the treatment arm of the study. Each received pulse dye laser treatment (585 nm, 1.5-msec pulse duration, 5-mm spot size, 7-8 J/cm(2)) for three to six treatments at 8-week intervals. Half of the scar was treated with the laser and the other half was used as a control. All patients were assessed for subjective improvement with the use of a structured questionnaire and objectively with ultrasonography for thickness and a cutometer for viscoelasticity. Scars were marked on every patient and mapped with a translucent paper at the first appointment to ensure the consistency of location. At the end of the study, 15 patients from the prevention group (15 scars) and 23 patients from the treatment group (34 scars) agreed to return for spectrophotometer assessment.

RESULTS

Fifty-four percent of patients in the prevention group and 66% of patients in the treatment group considered their scars to be better or much better. For both groups of patients, there was significant improvement in term of pruritics after laser treatment. For objective assessment, although scar thickness reduced significantly compared to baseline in the treatment group, such change was not significant when changes in the control side were taken into consideration. There was insignificant change in viscoelasticity. Spectrophometer assessment indicated a significant degree of lightening in the treatment group.

CONCLUSION

Our study indicated that although there was significant symptomatic improvement, there was an insignificant degree of objective improvement in terms of scar thickness and viscoelasticity in the prevention group compared to the control group. Our findings are in line with several previous controlled studies and contradict the results of several others. Such differences can be due to differences in assessment methodology, laser settings, skin type, and scar location. Suprapurpuric pulsed dye laser should not be considered as the standard of practice for the treatment and prevention of hypertrophic surgical scars especially in the chest in Asians patients.

Tuberculous meningitis with spinal tuberculous arachnoiditis

This report is of a 36-year-old woman who initially presented with confusion and fever. Subsequent investigations showed tuberculous meningitis with acute hydrocephalus. Ventriculoperitoneal shunt was performed and anti-tuberculosis therapy was given. The patient was later noticed to have weakness of both lower limbs and urinary retention. Magnetic resonance imaging of the thoracic spine showed radiological features of tuberculous arachnoiditis with cord compression. Decompressive laminectomy was performed and high-dose systemic corticosteroid was given. A high level of awareness is required when diagnosing tuberculous arachnoiditis and the importance of high-dose corticosteroid in the treatment regimen is emphasised.

Before the paradigm shift: concepts and communication between doctors and nurses in a burns team

The evolution of care delivered by a multidisciplinary burns team is a function of the effectiveness of the professional communication between team members. In this exercise, we have explored concepts and communication between nurses and doctors in a burns team. Loosely structured weekly meetings were held over a 4-month period. The explicit objective was to determine and define the current model of burns care in a regional burn centre. The implicit objective, however, was to develop a mutual appreciation of actual and potential problems in communication. Consensus task identification was achieved at the end of each meeting with full compliance in completing the tasks before the next meeting. Although there was a unanimous commitment to the team concept, traditional, professional, paradigms persist. For nurses, the concept of holistic modelling predominated, whilst the disease centred paradigm remained the focus of medical modelling. Linguistic, cultural and professional barriers to effective communication were identified but did not readily conform to prior expectations. Experience in burns care can transcend these barriers more effectively than a common culture or profession. In conclusion, team work and team building is a complex process that can benefit from an ongoing process of re-evaluation. An obvious yet common error is to assume a level of mutual understanding that does not in fact exist. Stepping aside to re-explore fundamental principles on which team members base their personal and professional practice can help in elucidating and determining new paradigms of care, which can be evaluated and appropriately implemented. The consensus conclusion was that this approach was a very valuable investment in time in pursuing excellence in the field of burns care.

Chemical assaults in Hong Kong: a 10-year review

The aim of this study was to assess the patients admitted to Prince of Wales Hospital Burns Unit, Hong Kong between September 1991 and August 2001 following chemical assault. A total of 2319 burns were admitted during the study period of which 19 had been subjected to chemical assault. All victims sustained a burn injury to the head and neck area and 47% of victims' eyes were burnt. A total of 84% required surgical intervention. Where a reason for the attack was admitted most were due to relationship difficulties. This study has defined the victims of chemical assault in Hong Kong. At a time when the overall number of assaults in Hong Kong is at its lowest level for 5 years it is of concern that there appears to have been a recent increase in the number of chemical assaults in Hong Kong.

Outcome analysis of 286 severely burned patients: retrospective study

OBJECTIVE

To evaluate the outcomes of severely burned patients treated at a regional burns unit and to develop a predictive model for survival and length of hospital stay for major burn patients in Hong Kong.

DESIGN

Retrospective study.

SETTING

Burns unit of a regional public hospital, Hong Kong.

PATIENTS

Two hundred and eighty-six severely burned patients treated from March 1993 to February 2000.

MAIN OUTCOME MEASURES

Details of demographics, mechanism of burn, extent of burn, incidence of inhalation injury, length of hospital stay, and mortality rate were recorded and entered into a database. Stepwise logistic regression and linear regression were applied to develop a predictive model for mortality and morbidity, respectively.

RESULTS

Of 286 major burn patients treated in this 7-year period, 25 patients died from their injuries, yielding a mortality rate of 8.7%. Stepwise logistic regression was applied to develop a predictive model for mortality. We found that inhalation injury, age, and total body surface area involvement were independent significant predictors of death. Accuracy of this predictive model reached 93%. Similarly, stepwise linear regression was used to develop a predictive model for length of hospital stay. Sex, inhalation injury, total body surface area of burn, and total body surface area(2) of burn were significant predictors of length of hospital stay (R(2)=0.2). Only three patients' duration of hospital stay was more than three standard deviations from the predicted length of hospital stay.

CONCLUSION

A predictive model for mortality and length of hospital stay has been developed for major burn patients in Hong Kong. This model may help clinicians to counsel patients and relatives at an early stage of care, to provide a basis from which new treatment plans can be compared, and to facilitate efficient allocation of valuable medical resources.

Endoscopic-assisted subcutaneous mastectomy and axillary dissection with immediate mammary prosthesis reconstruction for early breast cancer

BACKGROUND

Endoscopic surgery has been applied successfully in breast lump excision, breast augmentation, subcutaneous mastectomy for gynecomastia, and axillary dissection. Since subcutaneous mastectomy has been proven to be oncologically safe for early breast cancer, we have sought to develop a reproducible minimally invasive endoscopic-assisted technique to address this condition.

METHODS

Between December 1998 and May 1999, endoscopic-assisted subcutaneous mastectomy and axillary dissection with immediate reconstruction using a mammary prosthesis was performed in nine patients with early breast cancer at the Prince of Wales Hospital, Hong Kong. A 5-cm skin incision was made along the line of the lowest axillary skin crease. Dissection was continued down to the lateral border of the pectoralis major muscle. A subpectoral pocket was gently created by an endoscopic breast dissector. The endoscopic breast retractor and 10-mm/30 degrees scope were introduced into the subpectoral pocket, and further dissection was carried out using a 7-in harmonic scalpel under endoscopic vision down to a level 1 cm caudal to the inframammary fold. This subpectoral space was used for the insertion of the mammary prosthesis later on. Endoscopic-assisted subcutaneous mastectomy was performed afterward. Combined level I and level II axillary dissection was carried out via the same incision under direct vision.

RESULTS

Apart from minor skin flap bruises in our first two patients, there were no major complications. Histological examination of all the specimens showed clear margins. Postoperative radiotherapy and chemotherapy were given in the usual manner. All patients were satisfied with the reconstructive outcome.

CONCLUSIONS

We have described a novel endoscopic technique for subcutaneous mastectomy with immediate mammary prosthesis reconstruction in treating early breast cancer patient. This technique can minimize skin incision, reduce blood loss, and improve reconstructive outcome. It is easy to learn and well accepted by patients.

An in vivo study comparing the efficacy and complications of diode laser and long-pulsed Nd:YAG laser in hair removal in Chinese patients

BACKGROUND

Lasers with long wavelengths are less well absorbed by melanin and are considered to be particularly suitable for hair removal in dark-skinned patients.

OBJECTIVE

To compare the efficacy and complications of 800 nm diode and long-pulsed 1064 nm Nd:YAG lasers in laser-assisted hair removal in Chinese patients.

METHODS

Fifteen women had hair removal treatments (13 axillae and 2 legs) with diode laser on one side and Nd:YAG laser on the other. They were followed up for 36 weeks. Subjective assessments included the degree of immediate pain and the degree of hair regrowth. Clinical photographs were taken for evaluation by two independent observers to assess complications and the degree of hair regrowth.

RESULTS

Long-pulsed Nd:YAG laser was found to be significantly associated with a greater degree of immediate pain after laser surgery (P =.0001, independent sample t-test) and also had a longer laser time (P =.0001, independent sample t-test). Besides transit adverse effects such as erythema and perifollicular edema, only one patient developed hypopigmentation at week 6 which resolved by week 36. Although regrowth rates were low at week 6 (subjective rates were 23% and 19% for Nd:YAG and diode laser, respectively), most patients had significant regrowth at week 36 (subjective regrowth rate 91% for both long-pulsed Nd:YAG and diode lasers).

CONCLUSION

Diode 800 nm and Nd:YAG 1064 nm lasers are safe in laser-assisted hair removal in Chinese patients, and besides immediate pain, there was no other significant adverse effect. Most patients experienced regrowth 36 weeks after a single treatment. Further study is necessary to determine the long-term clinical efficacy and complications of laser-assisted hair removal with these systems in dark-skinned patients.

A retrospective study on the efficacy and complications of Q-switched alexandrite laser in the treatment of acquired bilateral nevus of Ota-like macules

BACKGROUND

Acquired bilateral nevus of Ota-like macules (ABNOM), or Hori's macules, is a common Asian condition that is characterized by bluish hyperpigmentation in the bilateral malar regions. Unlike nevus of Ota, ABNOM is an acquired condition that often develops after 20 years of age and involves both sides of the face, but there is no mucosal involvement. Recently Q-switched (QS) 1064 nm Nd:YAG lasers have been effective in clearing this condition. The effectiveness of QS alexandrite lasers has not yet been studied.

OBJECTIVE

To retrospectively assess the efficacy and complications of QS alexandrite lasers in the treatment of ABNOM.

METHODS

Thirty-two Chinese women with ABNOM ranging in age from 28 to 66 years were involved in the study. All underwent QS alexandrite laser treatment (755 nm, spot size 3 mm, 8 J/cm(2)). Topical hydroquinone and tretinoin cream were given to those with hyperpigmentation after the laser surgery. Clinical photographs were taken before and after laser surgery and assessed by two independent observers. The degree of clearing was scored and complications, including hypopigmentation, hyperpigmentation, scarring, and erythema, were assessed.

RESULTS

The mean number of treatment sessions was 7 (range 2-11) and the mean treatment interval was 33 days. Both observers identified more than 80% of the patients as having more than a 50% degree of clearing, and complete clearance was seen in more than 28% of patients. Although most patients had postlaser hyperpigmentation and were on depigmentary regimes, the hyperpigmentation was seen in only 12.5% of the patients during photographic evaluation. Hypopigmentation was seen in 50% of patients and erythema in 41%.

CONCLUSION

QS alexandrite appears to be effective in the treatment of ABNOM. Postoperative pigmentary changes were frequent and the use of topical depigmentary agents was necessary to achieve a satisfactory result. Transient hypopigmentation risk was high, affecting up to 50% of the patients. Further study is warranted to compare the efficacy and complications of different laser systems in the treatment of this condition.

A prospective controlled clinical study of skin donor sites treated with a 1-4,2-acetamide-deoxy-B-D-glucan polymer: a preliminary report

The effect of Hyphecan (1-4,2-acetamide-deoxy-B-D-glucan) on skin donor site healing was compared with the standard skin donor site dressing Kaltostat (calcium sodium alginate) in 35 burn patients with 70 skin donor sites prospectively. The median time of wound healing for the Hyphecan group was 12 days with an average of 13.1+/-4.0 days (ranged from 9 to 28 days) while the Kaltostat group had a median healing time of 12 days (ranged from 8 to 28 days) with a mean of 13.0+/-4.1 days. The difference in healing time between these two groups was statistically insignificant with a P-value of 0.95. The infection rate was 2.9% for both Hyphecan and Kaltostat. These 35 patients had been followed up from 10 to 16 months and no difference in long-term donor site morbidity between Hyphecan and Kaltostat had been observed. This finding was encouraging because the cost of Hyphecan is less than 50% of Kaltostat and it may be worthwhile to explore the clinical application of Hyphecan in other area of burns treatment.

Odontogenic subperiosteal abscess of orbit: a case report

Subperiosteal abscess of orbit is an uncommon but serious complication of orbital infection. We report a case of a 78 year old gentleman who presented with bilateral periorbital oedema and proptosis. Computerised tomography of orbit revealed bilateral dilated superior ophthalmic veins. Bilateral carotid-cavernous fistula was initially suspected. Serial imaging showed an increasing bilateral subperiosteal lesion of the orbit. Fine needle aspiration confirmed subperiosteal abscess. A high level of awareness is necessary in diagnosing subperiosteal abscess.

Skin care in burn patients: a team approach

Skin care is an important but often neglected issue in burn management. Newly healed burn skin is fragile, itchy, dry, and susceptible to sunburn. Without proper skin care in burn patients, they may suffer from sleep and mood disturbances, depression, and poor compliance to treatment that can jeopardize the rehabilitation process. At the Prince of Wales Hospital, skin care has been managed since February 1996 by a team consisting of plastic surgeon, dermatologist, occupational therapist and nursing specialist. The purpose of this study was to evaluate the impact of a skin care program run by a Skin Care Team on the rehabilitation of burn patients in a tertiary burn centre. The role of different members of the team was also discussed.

Contact burn by charcoal in an attempted suicide

A 23-yr-old lady was inadvertently burned during an attempted suicide. After quarrelling with her boyfriend, she attempted to commit suicide by using alcohol, benzodiazepine and burning charcoal within her sealed bedroom. Her left leg fell over the edge of the bed while she was half-conscious, that resulted in direct contact with the hot pot causing 1% full thickness burn and burn of her left tibialis anterior and extensor digitorum longus. She was initially resuscitated with 100% oxygen and gastric lavage and subsequently was managed in the Burns Unit for wound care, surgical debridement of the burn wound and skin graft, and psychological support. Burning charcoal in a sealed room is an emerging form of suicide in Hong Kong and this is the first case complicated by a burn wound in our locality. A holistic approach to tackle the bio-psycho-social aspects of individual's problem is advocated.

Assault by burning--a reappraisal

Assault by burning is a serious form of trauma that often results in higher incidence of inhalation injury, longer intensive care unit (ICU) and hospital stay, and higher mortality rate than is observed in the general burn population. We evaluated the epidemiology and outcome of assault burn victims treated in a tertiary burn center over a 6-year period. Among the 1063 acute burn patients who had been admitted to the Burns Unit between March 1993 and February 1999, 28 (2.6%) had assault burn injuries either by scald, chemical or fire. The mean extent of burn was 21.9%+/-20.8% (range 2-90%) total body surface area and the mean length of hospital stay was 65.2+/-107.3 days (range 1-565). Nineteen out of 25 patients (67.9%) underwent 76 operations. Nine patients had inhalation injuries requiring intubation and ICU admission. Three patients died in the series, which yielded a mortality rate of 10.7%. Compared to the general burn population, the assault burn group had significantly larger burn size (P<0.001), higher incidence of inhalation injury (P<0.001), longer ICU and hospital stay (P<0.001), and higher mortality rate (P<0.005). When these 28 victims were grouped according to the type of assault burn injury into a fire group, chemical group and scald group, all the 9 ICU admission and the 3 mortalities belonged to the fire group. Assault by fire resulted in larger burn size (P=0.03), more inhalation injury (P<0.001) and longer ICU stay (P=0.02). Although the fire group had a longer hospital stay and higher mortality rate, this was statistically insignificant.

A study of burn injuries in the elderly in a regional burn centre

We evaluated the epidemiology and outcome of 94 elderly burn patients of age 60 years or older treated in a local burn centre over a period of 6 years. There were 44 males and 50 females with a male to female ratio of 0.88 and an average age of 73.8+/-9 years. The mean extent of burn was 13.3+/-18.4% total body surface area (TBSA) with 14 patients (15%) suffering from a burn size >20% TBSA. The vast majority of injuries (90%) occurred at home. Scalds resulted in 62 admissions (66%) and flame burns accounted for another 29 admissions (31%). The burns predominantly involved the extremities and the trunk. Four patients had inhalation injuries and required admission to the Intensive Care Unit for ventilatory support. The majority of patients (60%) did not require any operations. The mean hospital stay of the survivors was 30.1+/-34.1 days and 35% of them stayed less than 2 weeks. Fifty-five patients (59%) had at least one pre-existing medical problem requiring long-term medication and 41 patients (44%) were living alone. Sixty-three patients (67%) presented more than 8 h after the burn injuries and 34 patients (36.2%) had no first aid treatment of their burn wounds. In addition, 40 patients (42.5%) had their wounds treated inappropriately. Seven patients died in this series which yielded a mortality rate of 7.4%. The outcomes of early versus late excision and grafting were also analyzed.

An analysis of 550 hospitalized pediatric burn patients in Hong Kong

A total of 550 acute burn patients under the age of 15 years were admitted to the Burns Unit of Prince of Wales Hospital, Hong Kong between March 1993 and February 1999. There were 337 males and 213 females with a male to female ratio of 1.58:1. The median age was 2.5 years and the median burn size was 5% total body surface area (TBSA). Toddlers of age < 2 years accounted for 235 (42.7%) of admission. Domestic burns resulted in 481 (87.5%) injuries followed by play-related burns that caused 34 (6.2%) admissions. Scalding was the most common cause of injury, which accounted for 497 (90.4%) admissions, followed by flame burns, which resulted in 45 (8.2%) injuries. Nine patients (1.6%) had inhalation injury requiring intubation and ventilatory support. The median hospital stay was 8 days and there was no seasonal variation in admission. The majority of patients (80.2%) had their wounds healed without any operation. Only 19 out of 550 patients (3.5%) had burns of 30% TBSA or larger, and only nine patients (1.9%) had inhalation injuries. Only one patient died in this series, which yielded a mortality rate of 0.2%.

A prospective study of the effect of botulinum toxin A on masseteric muscle hypertrophy with ultrasonographic and electromyographic measurement

We evaluated the effect of botulinum toxin A on masseteric muscle hypertrophy by using ultrasound and electromyography. Five patients (four with bilateral and one with unilateral masseteric muscle hypertrophy) were studied prospectively. In each patient, ultrasound-guided percutaneous intramuscular injection of botulinum toxin A was carried out. The change in muscle bulk was evaluated using serial ultrasonography and the electrical activity was assessed with electromyography. All five patients (nine hypertrophic muscles) showed a good response, with the maximal effect of a 31% reduction in muscle bulk seen 3 months after treatment. The effect remained stable one year after injection for six of the hypertrophic muscles, whereas three muscles needed a second injection to maintain the atrophy. This preliminary prospective study suggests that botulinum toxin A is a safe alternative method of treating masseteric muscle hypertrophy. However, the effect may be temporary and further intramuscular injection may be required to maintain atrophy.

Effect of the blood substitute diaspirin crosslinked hemoglobin in rat mesenteric and human radial collateral arteries

The actions of the blood substitute diaspirin crosslinked hemoglobin (DCLHb) were investigated in rat (small mesenteric artery) and human (radial collateral artery) resistance vessels mounted in a wire myograph for isometric tension recording. DCLHb did not contract resting vessels from rats, but vasoconstrictor responses were observed in isolated arteries and perfused mesenteric beds prestimulated with threshold concentrations of methoxamine. The DCLHb contractile responses were greatly attenuated by N(G)-nitro-L-arginine methyl ester hydrochloride (L-NAME) or endothelial removal, whereas BQ-123 (endothelin A receptor antagonist), prazosin (alpha1-adrenoceptor antagonist), or indomethacin (cyclooxygenase inhibitor) had no effect. Endothelium-dependent relaxations to carbachol in both rat mesenteric and human radial collateral artery were inhibited by DCLHb. Relaxations to carbachol were studied in the presence of L-NAME or 25 mM KCl to investigate the effect of DCLHb on endothelium-derived hyperpolarizing factor (EDHF) and nitric oxide, respectively. In both rat and human vessels, EDHF-mediated relaxations were not affected by DCLHb preincubation, whereas the nitric oxide component of carbachol-induced relaxations was practically abolished. In conclusion, inhibition of the effects of basal nitric oxide release underpins the vasoconstrictor effects of DCLHb. DCLHb effectively abolishes the nitric oxide component of carbachol-induced relaxation, with no effect on the EDHF-mediated component in both isolated rat mesenteric and human radial collateral arteries.

Management of paraffinoma of the breast: 10 years' experience

Paraffin injection was regarded as a simple and effective method of improving body contour. It was widely used in breast augmentation until the long-term complication of paraffinoma was recognised. Paraffinoma of the breast can present as a spectrum of disease ranging from a painless mass to a destructive ulcer simulating breast cancer. This makes it difficult to make the correct diagnosis and provide suitable treatment. Eight patients with paraffinoma of the breast have been managed at a teaching hospital over a 10 year period. All were females, with a mean age of 65.6 years (range: 57-73 years). The average time between paraffin injection and the onset of symptoms was 24 years (range: 11-30 years). These patients have been followed up for between 3 and 10 years (mean: 6.1 years). One patient died of congestive heart failure 4 years after bilateral mastectomy for painful paraffinomas of the breasts. Another patient had a coexisting infiltrative ductal carcinoma of the breast. The clinical presentations, radiological appearances, histopathological features and the treatment are discussed.

Suicidal burns in Hong Kong Chinese

There were 1063 acute burn patients admitted to the Burns Unit of Prince of Wales Hospital, Hong Kong, between March 1993 and February 1999. Eleven patients (1%) were burned due to attempted suicide. Seven were males and four were females, with a male:female ratio of 1.75:1. The median age was 38 years (range: 20-49 years) and the median extent of the burns was 55% total body surface area (range: 1-95%). Ten patients (90.9%) were self-incinerated and one patient attempted suicide by jumping into a hot bath. Seven patients (63.6%) suffered from severe smoke inhalation injury that required immediate intubation for ventilatory support. The average number of operations for the survivors was 3.7 (range: 0-8) and their median hospital stay was 42 days (range: 2-92 days). Four patients (36.4%) died from their injuries. Suicidal burns were more common among unemployed males with a history of psychiatric illness and substance abuse. Town gas (naphtha: a mixture of 49% hydrogen, 28.5% methane, 19.5% carbon dioxide and 3.0% carbon monoxide) was the most frequently used agent for self-immolation because it is probably the most convenient source of a fire accelerant in Hong Kong. Compared to the general burn population, this suicide group had a larger extent of burns, higher incidence of inhalation injury, required more operative treatment and longer hospital stay with a higher mortality rate.

An epidemiological study of 1063 hospitalized burn patients in a tertiary burns centre in Hong Kong

A total of 1063 acute burn patients were admitted to the Burns Unit of Prince of Wales Hospital, Hong Kong between March 1993 and February 1999. There were 678 males and 385 females with a male to female ratio of 1.76:1. The median age was 13.1 year-old and the median burn size was 6% total body surface area (TBSA). Pediatric patients under the age of 15 year-old accounted for 550 (51.7%) admissions and 235 (42.7%) of them were toddlers <2 year-old, while adult patients of age above 15 year-old accounted for the other 513 (48.3%) admissions. There was no seasonal variation in admission. Domestic burns resulted in 756 (71.1%) injuries followed by industrial burns that caused 175 (16.5%) admissions. The median hospital stay was 9 days and 54 patients (5.1%) had inhalation injury requiring intubation and ventilatory support. Twenty-four patients died in this series which yielded a mortality rate of 2.3%. The median age for this mortality group was 46.6 year-olds with a median extent of burns of 68% TBSA. There were 16 males and 8 females with a male to female ratio of 2:1. Eighteen (75%) patients had flame burns and 15 (83.3%) of them had inhalation injury. The mortality group had significantly larger burn size (P<0.001), higher incidence of inhalation injury (P<0.001) and older age (P<0.001) compared to the survivors.

Playing with fire--a significant cause of burn injury in children

We report our experience with 50 patients who were burned as a result of playing with fire over the period of January 1993 to December 1999. There were 43 males and 7 females with a male to female ratio of 6.1:1. The average age was 12.3+/-10.3 year with 39 (78%) patients under the age of 15. The mean extent of burn was 6.4+/-10.7% total body surface area (TBSA) and 2 children had extensive burns >30%. The burns predominantly involved the head and neck region, upper limb, hand and lower limb. There was no mortality in our series. Wax and fireworks were recognized as the two major burn causing agents in these 50 patients. Risk factors associated with these injuries as well as preventive measures were also presented.

Corneal perforation with extrusion of lens in a burn patient

The incidence of ophthalmologic injuries has been reported to be between 20 and 25% in all the burn patients. As most of the eye injuries are associated with severe burns, attention is often directed towards the life-threatening events and eye injuries may be overlooked and undertreated. This case report presents a patient who had 40% flame burn and had recently been transferred from another hospital. He was examined by an ophthalmologist at the referring hospital and it was documented that both of his eyes were normal. He was transferred into the Burns Unit at the Prince of Wales Hospital 8 h later. Unfortunately, all the attention was directed to save his life and it was not until post-burn day 11 that he was found to have right corneal ulceration. Despite vigorous ophthalmologic treatment, the cornea perforated 2 days later with subsequent extrusion of the lens. In view of his grave prognosis with multi-organ failure, he was treated conservatively and he died the following day. It is mandatory to refer patients with facial burns to the ophthalmologist for ocular examination. We recommend that serial eye examinations should be carried out in burn patients who are unconscious or intubated for ventilatory support even if the initial ophthalmologic examinations are normal as the potential risk of serious ocular injuries are high in this particular group of patients.

Iatrogenic burn caused by an alcohol lamp

Iatrogenic injury is an intrinsic risk of all medical procedures. Various kinds of iatrogenic complications have been extensively reported and recognized. Two patients were referred to the Prince of Wales Hospital for iatrogenic flame burn caused by the breakage of an alcohol lamp during ENT examination. They were 8 and 9 years old and sustained 12 and 17% intermediate to deep dermal burns respectively. There was no eye or inhalation injury. They were treated initially at the referring hospital. Despite having the best possible treatment, the parents were hostile to and demanding of the medical attendants and the patients were uncooperative throughout the whole treatment period. Rehabilitation of the two children was jeopardized. The situation was very difficult when they were first seen at the Prince of Wales Hospital. The burn surgeon at the Prince of Wales Hospital, as a third party, managed to act as a bridge between the referring hospital and the patients and their families. Several meetings were held and the best interests of the two patients was addressed. The compensation issue was also settled without formal legal prosecution.

A retrospective analysis of complications in the treatment of nevus of Ota with the Q-switched alexandrite and Q-switched Nd:YAG lasers

BACKGROUND

Studies on the use of Q-switched alexandrite (QS alex) and QS Nd:YAG lasers in the treatment of nevus of Ota were limited to case reports and small series. There was no study that looked at the complication rate of these systems.

OBJECTIVE

To retrospectively study the complication rate of nevus of Ota patients that were treated with QS alex laser, QS Nd:YAG laser, or a combination of both.

METHODS

The study was performed in a teaching hospital and a private hospital, where 513 patients with nevus of Ota had been treated since 1993. The 171 patients with 211 treatment sites were evaluated retrospectively following treatment with QS alex laser only (n = 58), QS Nd:YAG laser (n = 105) only, or a combination of both systems (n = 48). Patients were called back to be interviewed and examined by two independent clinicians to look for evidence of complications.

RESULTS

Of the treatment sites, 15. 3% had hypopigmentation, 2.9% had hyperpigmentation, and texture changes and scarring were seen in 2.9% and 1.9%, respectively. The combined treatment group was associated with a significantly higher risk of complications. Thirteen patients had recurrence of their nevus after complete or near-complete clearance with laser treatment.

CONCLUSION

Hypopigmentation is common after the use of QS laser for lightening of nevus of Ota. This particularly applies when alternate treatment with QS alex and QS Nd:YAG is used. Recurrence is an important issue and must be taken into consideration, especially when children are treated.

An in vivo trial comparing the clinical efficacy and complications of Q-switched 755 nm alexandrite and Q-switched 1064 nm Nd:YAG lasers in the treatment of nevus of Ota

BACKGROUND

Q-switched 755 nm alexandrite (QS alex) and Q-switched 1064 nm Nd:YAG lasers are effective in the treatment of nevus of Ota. Our previous in vivo study indicated that patients better tolerate QS alex than QS 1064 nm Nd:YAG laser. However, in terms of clinical efficacy and long-term complications, the study did not indicate which laser is superior. Although both machines may appear to be similar in effectiveness, the low number of treatment sessions may contribute to this apparent lack of difference.

OBJECTIVE

The aim of this study was to compare the clinical efficacy and complications of QS 755 nm alex and QS 1064 nm Nd:YAG lasers in the treatment of nevus of Ota after three or more treatment sessions.

METHOD

Forty patients were recruited for this study and all had received three or more laser treatment sessions with an interval of at least 2 months between each. Half of the lesion was treated with QS alex and the other half with QS 1064 nm Nd:YAG laser. The degree of lightening was assessed subjectively by the patient using a visual analog scale and objectively by two independent clinicians. Patients were called back to be examined for evidence of complications.

RESULTS

In terms of subjective degree of lightening, QS 1064 nm Nd:YAG laser was found to be significantly more efficacious than QS alex (P = 0.018). Both clinicians also found QS 1064 nm Nd:YAG laser to be more effective, but statistical significance was only detected in one, not both of their scores (P = 0.005 and 0.414 for observers 1 and 2, respectively). More patients that received QS Alex developed complications (4 for QS alex and 2 for QS Nd:YAG), but the difference was not statistically significant.

CONCLUSION

QS 1064 nm Nd:YAG laser appears to be more effective than QS alex in the lightening of nevus of Ota after three or more laser treatment sessions. However, the majority (55%) of the patients reported no differences in results between the two lasers, and only one of the two observers noted statistically significant improvement of QS 1064 nm Nd:YAG over QS alex.

Bizarre paediatric facial burns

Child abuse and neglect account for a significant number of paediatric burn injuries. It is of great importance because of the high mortality, high frequency of repeated abuse, as well as the physical, psychological and social sequelae that it causes. Burn abuse is often under-recognized and under-reported because it is difficult to define non-accidental injury. On the other hand, false accusation of burn abuse is extremely damaging to the family. Bizarre and unusual burn injuries can be caused by accident and should not automatically be assumed to be deliberate injury. Three boys of age 1-7 years with bizarre facial burns were admitted to the Burns Unit at the Prince of Wales Hospital between February 1995 and July 1999. One was burned by his baby-sitter with hot water steam and the other two were burned by their mothers with hot boiled eggs. The unusual causes of their burns raised the suspicion of child abuse and formal investigations were carried out by the Social Services Department. Detail assessment including a developmental history of the child and the psychosocial assessment of the family revealed that these three boys were burned because of poor medical advice and innocent cultural belief.

In vivo trial comparing patients' tolerance of Q-switched Alexandrite (QS Alex) and Q-switched neodymium:yttrium-aluminum-garnet (QS Nd:YAG) lasers in the treatment of nevus of Ota

BACKGROUND AND OBJECTIVES

Different types of Q-switched lasers have been found to be effective in the treatment of nevus of Ota. However, a clinical trial involving in vivo comparison of the use of different laser systems has not been performed. The aim of the present study was to compare the patient tolerance of Q-switched Alexandrite (QS Alex) and Q-switched neodymium:yttrium-aluminum-garnet (QS Nd:YAG) lasers in the treatment of nevus of Ota.

STUDY DESIGN/MATERIALS AND METHODS

Thirty-three patients (11 male, 22 female) were recruited for this study, and 45 treatment sessions were performed. Half of each lesion was treated with QS Alex and the other half with QS Nd:YAG laser. Patients were interviewed with a visual analog scale questionnaire immediately after treatment and 1 week later. Questions included the degree of pain, swelling, and bleeding.

RESULTS

The immediate pain after treatment was more severe for QS Alex than for QS Nd:YAG laser. However, 1 week after laser therapy, most patients found QS Alex to be superior.

CONCLUSION

Patients tolerate QS-Alex better than QS Nd:YAG. This finding is important because patients with nevus of Ota are often children, and multiple laser sessions are necessary for complete resolution of the lesion.