After the Indian Ocean tsunami: Singapore's contribution to the international disaster victim identification effort in Thailand

This paper describes the international disaster victim identification (DVI) response mounted in Thailand, with particular reference to Singapore's contribution to this process, in the wake of the Asian tsunami of 26 December, 2004, which devastated parts of more than 10 countries in and around the Indian Ocean and claimed more than 200,000 lives. Although Singapore was unscathed by this natural calamity, over 30 Singaporean visitors were counted amongst the thousands of deceased victims, mostly in Thailand. The systematic application of forensic pathology, forensic dentistry, DNA profiling, and fingerprinting to human identification, especially of the bodies of various nationalities that were in advanced states of putrefaction, was crucial to the entire DVI process. The authors perceive that the resource implications arising from such a disaster, which is unprecedented in both its scale and reach in the international history of DVI, are immense. Forward planning, adequate funding and international cooperation are essential to mounting an effective response to any major mass disaster of the future.

Modulation of human dendritic-cell function following transduction with viral vectors: implications for gene therapy

Genetic modification of dendritic-cell (DC) function is an attractive approach to treat disease, either using mature DCs (mDCs) to immunize patients, or immature DCs (iDCs) to induce tolerance. Viral vectors are efficient at transducing DCs, and we have investigated the effect of transduction with a variety of viral vectors on the phenotype and function of DCs. Adenovirus (Ad), human immunodeficiency virus (HIV), equine anemia virus (EIAV), and Moloney murine leukemia virus (MMLV) all up-regulate costimulatory molecules and major histocompatibility complex (MHC) class II expression on DCs, as well as, in the case of Ad and lentiviral vectors, inducing production of Th1 and proinflammatory cytokines. Following transduction there is activation of double-stranded (ds) RNA-triggered pathways resulting in interferon (IFN) α/β production. In addition, the function of virally infected DCs is altered; iDCs have an increased, and mDCs a decreased, ability to stimulate a mixed lymphocyte reaction (MLR). Viral transduction of mDCs results in up-regulation of the indoleamine 2,3-dioxygenase (IDO) enzyme, which down-regulates T-cell responsiveness. Inhibition of IDO restores the ability of mDCs to stimulate an MLR, indicating that IDO is responsible for the modulation of mDC function. These data have important implications for the use of viral vectors in the transduction of DCs.

Immunolipoplexes: An Efficient, Nonviral Alternative for Transfection of Human Dendritic Cells with Potential for Clinical Vaccination

Genetic manipulation of dendritic cells (DCs) is important in the context of using either mature DCs to immunize patients or immature DCs to induce tolerance. Here, we describe a novel method of transfecting monocyte-derived human DCs using immunolipoplexes containing anti-CD71 or anti-CD205 monoclonal Abs. This results in up to 20% transfection, which can be increased to 20-30% if the immunolipoplexes are used to transfect CD14+ monocytes prior to differentiation into DCs. Transfected DCs can be substantially enriched using a drug-selection protocol during differentiation. Unlike adenoviral transduction, this nonviral transfection does not alter the expression of costimulatory molecules or the production of proinflammatory cytokines by DCs. In addition, DC function is unaltered, as assessed by mixed lymphocyte reactions. To test the feasibility of the immunolipoplexes and selection protocol for therapeutic intervention, we transfected DCs with the immunomodulatory enzyme indoleamine 2,3-dioxygenase (IDO). Allogeneic T cells exposed to IDO-expressing DCs did not proliferate, secreted more IL-10 and less Th1 and Th2 cytokines, and had a higher amount of apoptosis than T cells incubated with control DCs. Furthermore the remaining T cells were rendered anergic to further stimulation by allogeneic DC. These immunolipoplexes, which can be easily and rapidly assembled, have potential for clinical immunization, in particular for tolerance induction protocols.

Extracellular signal-regulated kinase induces cyclin D1 and Cdk-2 expression and phosphorylation of retinoblastoma in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies in Southeast Asia. Hyperphosphorylation of retinoblastoma (pRB) by cyclin/CDKs in G1/S transition is required for its inactivation and cell cycle progression. In the present study, we report that phosphorylation of pRB at Ser780 and Ser795 was detected in 71% (33 of 46) and 63% (29 of 46) of HCCs examined respectively. pRB protein was undetectable in 13% (6 of 46) of HCCs examined. Phosphorylated pRB was localized in the nuclei of hepatocarcinoma cells. Benign hepatocytes exhibited very weakly or no nuclear staining for phosphorylated pRB. Over-expression of E2F-1, cyclin D1, Cdk-2, Cdk-4 and cyclin A was found in 64% (30 of 46), 43% (26 of 46), 28% (11 of 46), 71% (33 of 46) and 63% (29 of 46) of HCCs examined respectively and this was correlated with elevation of ERK. Treatment of HepG2 cells with MEK1/2 inhibitor U0126 resulted in cell cycle arrest, downregulation of cyclin D1 and Cdk-2 expression and inhibition of pRB phosphorylation at Ser780 and Ser795. Ectopic expression of activated MEK1 in HepG2 cells increased cyclin D1 and Cdk-2 expression, phosphorylation of pRB at Ser780 and Ser795, and percentage of cells in S phase. Our data indicate that activated ERK plays an important role in cyclin D1 and Cdk-2 expression and phosphorylation of pRB at Ser780 and Ser795 in liver cancer cells.

Systemic administration of naked DNA with targeting specificity to mammalian kidneys

A major challenge for gene therapy is to be able to deliver efficiently the gene of interest to specific cell types. Here we describe a safe and simple effective naked DNA gene delivery method, via inferior vena cava (IVC) injection, to the recipient's kidneys. It was further demonstrated that gene expression was concentrated in the proximal tubular epithelial cells of the cortico-medullary region of the kidney. Confocal microscopy analyses demonstrated the presence of the exogenous DNA in the renal cell membrane 10 min postgene delivery. However, it was only by 30 min that the presence of the exogenous DNA could be detected in the cell cytoplasm and in the nuclei of the renal cells. Stable expression of the beta-galactosidase gene could be detected for up to 35 days and no toxicity or any adverse pathological effect associated with the delivery method could be observed. Importantly, this IVC gene delivery method could promote the targeting of genes to carcinoma established in the kidney of SCID mice. These results provide the first evidence to support that stable gene expression could be achieved in the renal cells of kidney and the established carcinoma in the kidneys following in vivo gene delivery with naked DNA and could therefore provide the potential to design protocols for the gene therapy of the kidney diseases.

Ductal carcinoma in situ with spindle cells: a potential diagnostic pitfall in the evaluation of breast lesions

AIMS

To evaluate the morphological features of 11 cases of breast ductal carcinoma in situ (DCIS) with spindle cells and to propose an approach to distinguish it from benign mimics. The association with neuroendocrine differentiation was also investigated.

METHODS

Cases of breast DCIS with a spindle cell component diagnosed in the Department of Pathology, Singapore General Hospital, between June 1996 and January 2003, were included in the study. The histological characteristics were documented, and immunohistochemistry for neuroendocrine markers, hormone receptors, cerbB2, smooth muscle actin (SMA) and high-molecular-weight (HMW) cytokeratins, was carried out. Electron microscopy was carried out on reprocessed paraffin-embedded material in three cases.

RESULTS

Of 11 women diagnosed with DCIS with spindle cells, four presented with nipple discharge, six with a breast lump, while one was discovered to have a screen detected density. The tumour size ranged from 3 to 41 mm. The proportion of spindle cells varied from 10% to 80% of the in-situ tumour cell population. Nuclear grade was low in seven cases and intermediate in four. Necrosis was observed in two cases. Architectural pattern was papillary in six cases, and mixed in the rest. Microinvasion was present in two cases, with possible microinvasion in another two. Immunohistochemistry for neuroendocrine markers synaptophysin and chromogranin showed positive reactivity for at least one marker in all but three cases; one of these latter cases demonstrated ultrastructural neurosecretory granules. Oestrogen and progesterone receptors were expressed in 10 and nine cases, respectively, while cerbB2 was positive in only one case. HMW cytokeratin immunoprofile revealed a general lack of immunostaining within the abnormal cell population; likewise, no positivity for SMA of the cellular proliferation was detected.

CONCLUSIONS

Almost all DCIS lesions with spindle cells disclose neuroendocrine differentiation. Although the distinction from benign florid usual hyperplasia may pose a diagnostic histological problem, the presence of diffuse neuroendocrine expression, in conjunction with the pattern of HMW keratin profile on immunohistochemistry, supports an in-situ neoplastic process. The absence of SMA immunostaining, in conjunction with negative reactivity for cytokeratins 5/6 and 14, makes the possibility of a myoepithelial proliferation unlikely.

The HercepTest and routine C-erbB2 immunohistochemistry in breast cancer: any difference?

INTRODUCTION

The proto-oncogene c-erbB2, located on chromosome 17q21, encodes a 185-kD transmembrane glycoprotein. It is known to be overexpressed, amplified, or both in 20% to 30% of breast cancers. C-erbB2 belongs to the human epidermal growth factor receptor (tyrosine kinase receptor) family that plays an important role in cell cycle regulation and differentiation. Although there are various methods to assess c-erbB2 status in breast cancer, protein overexpression determined by immunohistochemistry and gene amplification using fluorescence in situ hybridisation are most commonly utilised. This study compares the results of the DAKO HercepTest with the immunohistochemical assay (A0485, DAKO), which is routinely used in our pathology laboratory.

MATERIALS AND METHODS

Paraffin-embedded breast cancer tissues from 41 patients operated in a tertiary hospital during the year 2000 were subjected to immunohistochemistry by the above methods. C-erbB2 positivity was defined by cytoplasmic membrane staining of 2+ or 3+ intensity.

RESULTS

Overexpression of c-erbB2 protein was present in 36.6% and 41.5% of cases when detected by HercepTest and the DAKO A0485 antibody, respectively. There was almost perfect agreement between both methods (k = 0.898) when positive versus negative results were considered, and moderate agreement in terms of individual staining intensities (k = 0.554).

CONCLUSION

Routine immunohistochemistry using the DAKO A0485 antibody is a reliable, cost-effective alternative to the HercepTest in determining prognosis and suitability of patients for Herceptin therapy.

Endorectal magnetic resonance imaging and spectroscopy for the detection of tumor foci in men with prior negative transrectal ultrasound prostate biopsy

PURPOSE

We determined the ability of combined endorectal magnetic resonance imaging (MRI) and magnetic resonance spectroscopic imaging (MRSI) to detect prostate cancer foci prospectively in men with prior negative transrectal ultrasound (TRUS) prostate biopsy.

MATERIALS AND METHODS

Endorectal MRI with spectroscopy was performed in 24 consecutive patients with 1 or more prior negative TRUS prostatic biopsies for persistently increased prostate specific antigen and/or abnormal digital rectal examination. All studies were interpreted by a dedicated radiologist who reported areas of interest in the peripheral zone as normal, equivocal or suspicious on MRI and MRSI separately. Equivocal and suspicious areas were then correlated with a 3-dimensional prostate model. All patients underwent a standard TRUS 10-core peripheral zone biopsy with up to 4 additional biopsies targeted at the equivocal or suspected sites.

RESULTS

Prostate cancer was detected in 7 of 24 subjects (29.2%). Considering the equivocal category as test negative the sensitivity, specificity, positive and negative predictive values, and the accuracy of MRI, MRSI and combined MRI/MRSI for the detection of prostate cancer were 57.1%, 57.1% and 100.0%, 88.2%, 82.4% and 70.6%, 66.7%, 57.1% and 58.3%, 83.3%, 82.1% and 100%, and 79.2%, 75.0% and 79.2%, respectively. The site of positive biopsy correlated correctly in 50% and 28.6% of MRI and MRSI labeled suspicious cores, respectively.

CONCLUSIONS

MRI and MRSI have the potential to identify cancer foci and direct TRUS in patients with a previous negative TRUS biopsy. Further, larger studies are required to quantify the amount of benefit.

The effect of promethazine on postoperative pain: a comparison of preoperative, postoperative, and placebo administration in patients following total abdominal hysterectomy

BACKGROUND

Histamine receptors are involved in the development of inflammatory pain and hyperalgesia, and the use of antihistamines is advocated as an alternative for pain therapy and treatment of postoperative nausea and vomiting. We investigated the influence of timing of promethazine administration on postoperative pain outcomes.

METHODS

Ninety female patients undergoing total abdominal hysterectomy were randomly divided into three groups. All individuals received infusions of promethazine and normal saline before anaesthesia induction, and postoperatively the Pre group received promethazine 0.1 mg kg(-1) before anaesthesia and saline postoperatively, and the Post group received saline before anaesthesia and promethazine 0.1 mg kg(-1) postoperatively, while the Control group received two equivalent volumes of saline. Patients were treated using patient-controlled intravenous analgesia (PCA). The primary endpoint was pain intensity and morphine consumption. The secondary endpoint was postoperative nausea and vomiting.

RESULTS

Postoperative morphine usage was significantly lower in the Pre group (24.1 +/- 3.9 mg) relative to the Post (30.0 +/- 4.6 mg) and Control groups (32.1 +/- 4.8 mg) during the first 24 h postoperatively (P<0.05). The number and incidence of patients suffering from postoperative nausea in the first 24 h was six (21%), seven (23%), and 15 (47%) in the Pre, Post, and Control groups, respectively (P<0.05). The number and incidence of patients vomiting in the first 24 h was three (10%), two (7%), and 10 (32%) in the Pre, Post, and Control groups, respectively (P<0.05). The number of patients asking for rescue antiemetic in the first 24 h was one (3%), two (7%), and seven (22%) in the Pre, Post, and Control groups, respectively (P<0.05).

CONCLUSIONS

Our results suggest that preoperative administration of promethazine 0.1 mg kg(-1) reduces postoperative morphine consumption compared with postoperative and placebo administration, and that use of promethazine reduces PONV and the number of patients asking for rescue antiemetic in the first 24 h after surgery when compared with placebo.

Phenotypic and functional differences between human saphenous vein (HSVEC) and umbilical vein (HUVEC) endothelial cells

The vascular endothelial cell (EC) plays an essential role in the pathogenesis of inflammation, transplant rejection and tumour metastasis. Most research on vascular ECs uses human umbilical vein endothelial cells (HUVECs). However, HUVECs are derived from immune-naive foetal tissue, and show significant functional differences from adult vascular endothelium. In this paper, we characterise an alternative model based on human saphenous vein ECs (HSVECs), describe their culture conditions and provide a detailed functional comparison with HUVECs. Compared with HUVECs, HSVECs show an increased sensitivity to ox-LDL and a reduced response to cytokines, as indicated by adhesion molecule expression as well as leukocyte adhesion and transmigration. With respect to their ability to present antigen, HSVECs have a higher level of HLA-DR, CD40 and ICOS-L following cytokine stimulation. In addition, HSVECs upregulate the costimulatory ligand CD80 (B7.1) following CD40 ligation, and support allogeneic T cell proliferation, while HUVECs fail to express CD80. Due to differential expression of adhesion molecules, poorly differentiated tumour cell lines also showed more adhesion to HSVECs than to HUVECs. These results indicate that HSVECs have advantages over HUVECs for studying adult vascular endothelial pathology in vitro.

Gastrointestinal stromal tumor of the anus

We report a rare case of gastrointestinal tumor of the anus with an unusual presentation as a perianal lipoma. A 65-year-old man presented with a 2-month history of a painless perianal lump clinically resembling a perianal lipoma. Endoanal ultrasonography revealed a 3 x 3 cm2 mass in the intersphincteric plane. Following initial excision of the lesion, histological analysis revealed a stromal lesion comprising fascicles of spindle cells with a mitotic count of 4 per 50 x high power field. Immunohistochemical analysis displayed positive reactivity for CD34 with focal staining for CD117; S100, smooth muscle actin and desmin were not expressed. No evidence of local or distant metastatic disease was found on computed tomography of the abdomen and pelvis. The patient subsequently underwent abdominoperineal resection. The resected specimen contained a mural nodule measuring 0.7 cm, located 5 cm from the distal margin and 2 mm from the radial margin. Histological analysis confirmed a stromal tumor composed of spindle cells with mitoses up to 2 per 10 x high power field. The patient's recovery was uneventful and he was free of recurrence at the 1-year follow-up. Gastrointestinal stromal tumors of the anal canal are an extremely rare occurrence, and may mimic benign perianal lesions. Tumor size and mitotic count are the most important factors in prognosticating outcome. Oncologic resection and protracted follow-up must factor in their predilection for late recurrence and metastatic spread. The role of adjuvant therapy with STI571 here remains to be clearly defined.

Modulation of costimulation by CD28 and CD154 alters the kinetics and cellular characteristics of corneal allograft rejection

PURPOSE

To examine the effect of modulating the lymphocyte costimulation pathways through CD28 and CD154 (CD40 ligand) in a model of corneal allograft rejection, with particular interest in changes in the observed features of rejection.

METHODS

CD28 knock-out (CD28KO) and wild-type BALB/c control mice received corneal grafts from fully major histocompatibility complex (MHC)-mismatched C3H donors and were treated with CTLA4-Ig and/or anti-CD154 Ab on days 0, 2, and 4 after transplantation. Proliferation of BALB/c and CD28KO T cells in response to C3H stimulators was examined in a mixed lymphocyte reaction (MLR) in the presence of CTLA4-Ig or anti-CD154 Ab.

RESULTS

Corneal allograft survival in wild-type BALB/c mice (median survival time [MST] 14 days) was significantly prolonged by blockade of the costimulatory pathways with CTLA4-Ig or anti-CD154 Ab (MST 21 days and 25 days respectively). MST in recipients treated with CTLA4-Ig and anti-CD154 Ab in combination was 29 days, not significantly longer than graft survival in single-treatment groups. MST in CD28KO recipients was 46 days and was not prolonged after treatment with anti-CD154 Ab (MST, 43 days). A similar result was found in the MLR, in which anti-CD154 Ab had no effect on proliferation of CD28KO compared with wild-type T cells. In CTLA4-Ig-treated CD28KO, grafts were rejected at an accelerated tempo, similar to that in wild-type BALB/c recipients (MST 16 days). More severe graft injury after the onset of rejection in untreated allograft recipients was accompanied by a higher number of graft-infiltrating CD45(+) cells, but similar proportions of CD4(+) and CD8(+) cells.

CONCLUSIONS

CD28- and CD154-mediated costimulation have significant functional roles in corneal allograft rejection. Agents that modulate CD28 and CD154 pathways delay onset and reduce the severity of observed allograft rejection. However, their use in combination did not have an additive effect, MLR data indicating that the CD40-CD154 system depends on a functioning CD28 costimulatory pathway.

Single institution's initial experience with sentinel lymph node biopsy in breast cancer patients

BACKGROUND

The sentinel lymph node is the first draining node from a cancer-bearing area and is therefore the first to manifest metastasis. In breast cancer it has been shown to predict the axillary status. Axillary dissection provides information determining prognosis and need for adjuvant therapy but carries a certain morbidity. Our aim was to determine the feasibility of detecting the sentinel node in a teaching hospital and whether the sentinel node accurately predicts the axillary status.

METHODS

All patients with stage I and II breast cancer and non-palpable axillary nodes were eligible, including those with previous excision biopsy. We excluded pregnant women, those with previous axillary surgery and women with advanced breast cancer with enlarged axillary nodes. The sentinel node was detected with technetium-99m-labelled tin colloid and vital blue dye and removed, and axillary clearance was performed.

RESULTS

A total of 312 patients were examined from August 1996 to December 1998. The mean age was 53 years (range 28-83) and mean tumour size 2.6 cm (range 0.2-9.0). The detection rate of the sentinel node was 86%. The sentinel lymph node predicted the axillary status with a sensitivity of 83% and specificity of 100%. The false-negative rate was 16.7%.

CONCLUSIONS

Detection of the sentinel lymph node is feasible and it can accurately predict the nodal status of the axilla. However, the high false-negative rate precludes as yet the use of sentinel lymph node biopsy in replacing axillary clearance as the standard of care for breast cancer.

Antibody targeted gene transfer to endothelium

BACKGROUND

One of the drawbacks of the currently available vectors for gene therapy is the lack of selectivity in gene delivery. We have therefore investigated a strategy to generate immunoliposomes to target non-viral vectors to cell surface receptors on endothelium.

MATERIALS AND METHODS

We have developed a novel method of coupling antibodies (Abs) to liposomes complexed to DNA, using mild heat treatment to aggregate the immunoglobulin G (IgG). The interaction of plasmid DNA, liposomes and Abs was measured using a gel retardation assay and a resonant mirror biosensor. The size of the transfection complex was determined by light scattering, and the binding and internalization of the complex to cells was followed using flow cytometry. The transfection ability was tested on cell lines and primary cells in vitro and human corneal or vascular tissues ex vivo.

RESULTS

The interaction of antibodies with liposomes is relatively stable (t(1/2) congruent with 45 min). The size of the liposome, Ab and DNA complex was found to be around 500 nm in 4% BSA. The addition of anti-transferrin receptor Abs increased the internalization of the liposome-DNA complex into cells. Abs against both transferrin receptor and E-selectin were shown to augment transfection efficiency of liposomes to cell expressing the appropriate antigens. They are also shown to be efficient in mediating gene delivery to corneal and vascular tissues ex vivo.

CONCLUSIONS

We have shown that our novel vector is capable of in vitro and ex vivo gene delivery to cells and human tissues including cornea, artery and vein. In particular, an Ab against E-selectin was effective at selectively delivering genes to activated endothelial cells expressing the adhesion molecule. Such a strategy will have applications for targeting these tissues prior to transplantation or autologous grafting, and, in the longer term, may allow in vivo targeting of gene therapy to inflammatory sites.

CerbB2 status in breast cancer: pathologic issues

INTRODUCTION

CerbB2 status determination in breast cancer is currently performed for predictive and prognostic information. However, much has yet to be learned about the accuracy, reproducibility and clinical correlation of the different testing methods available today. This is a review of the testing methods commonly in use and their applications in the management of breast cancer.

METHODS

A Medline search for review articles with keywords cerbB2, Her2 testing, immunohistochemistry (IHC), fluorescence in situ hybridisation (FISH) and breast cancer was done. Manual cross-referencing from the afore-mentioned articles and perusal of the package inserts, recommendations and manuals from the manufacturers of various commercially available test kits were also performed.

RESULTS

The 2 main methods of testing in use in most routine laboratories are IHC and FISH on formalin fixed, paraffin embedded, breast cancer tissue. There is no single, universally accepted method and the plethora of testing and interpretative protocols has confounded the issue of clinical correlation of cerbB2 status with outcome and patient selection for therapy. The current consensus in the literature is leaning towards FISH; however, as pointed out in this paper, the use of FISH as a routine test in most diagnostic laboratories is not yet a reality mainly due to cost, technical and manpower constraints. In this regard, IHC is by default the preferred choice in many routine laboratories.

CONCLUSION

Universal standardisation of testing methods for cerbB2 status determination, together with further clinical studies on the correlation of each method with outcome and response to therapy, will aid in the identification of the ideal method for stratifying patients with breast cancer into prognostic and optimal therapeutic groups.

Improved detection rate of prostate cancer using the 10-core biopsy strategy in Singapore

OBJECTIVES

To evaluate if changing the biopsy regime to 10 cores might improve the positive predictive value (PPV) of elevated prostate-specific antigen [PSA, elevated range, 4 to 20 ng per ml, normal range, < 4 ng per ml] for the diagnosis of prostate carcinoma.

METHODS

From February 2000 to April 2001, 191 patients, mean age 64 years [range, 38 to 85 yr], underwent transrectal ultrasound [TRUS] for either elevated PSA [elevated range, 4 to 20 ng per ml] and/or abnormal digital rectal examination [DRE]. A 10-core TRUS-guided biopsy of the prostate was performed. This included the standard sextant biopsy and two additional cores for each far lateral zone.

RESULTS

Using this technique, 47 out of 191 patients [24.6%] had prostate cancer. The PPV for PSA levels of 4.1 to 10.0 ng per ml and 10.1 to 20.0 ng per ml were 19.3% and 35.4%, respectively. The lateral cores contributed 21.3% of the cancer cases, which would have been missed if only sextant biopsies were performed.

CONCLUSIONS

With the 10-core biopsy method, the PPV for prostate cancer for patients with a PSA in the range of 4 to 20 ng per ml was in the range of 25%. This is significantly different from previous reports. The reason for this may be due to the adoption of a better, more uniform and systematic biopsy strategy for patients with elevated PSA, or it may be a true reflection of the current population incidence. Hence, this biopsy strategy is highly recommended.

Pseudodicentric (16;12)(q11;p11.2) in a type AB (mixed) thymoma

Genetic alterations of thymomas are rarely described in the literature. In this study, a previously unreported instance of aberrant karyotypic change consisting of 45,XX,pseu dic(16;12) (q11;p11.2) [cp23]/87-90,idemx2[cp4] in a Masaoka Stage II mixed thymoma or type AB thymoma affecting a 56-year-old Chinese woman is detailed. Abnormalities involving 12p containing important tumor suppressor-like genes have been documented especially in hematological malignancies. Recently, recurrent losses involving 16q, a locus known to harbor several tumor suppressor genes, have been described in type C thymomas (squamous cell carcinoma), suggesting a possible relationship between type AB thymoma and type C thymoma. Whether these genes are involved in the pathogenesis of type AB thymoma remain to be clarified and it is currently unclear if cytogenetic studies may eventually play a role in the classification of thymic tumors.

Bilateral synchronous renal oncocytoma: a case report and review

INTRODUCTION

Renal oncocytoma is a rare benign tumour.

CLINICAL PICTURE

A 73-year-old man presented with bilateral renal tumours, suggestive of renal cell carcinoma (RCC). Nephron-sparing surgery (NSS) and radical nephrectomy were performed. Both specimens revealed renal oncocytoma on final histology. A review of nephrectomy specimens showed 4 other solitary oncocytomas out of 250 RCCs over the period 1991 to 2000. Diagnosis of oncocytoma could only be firmly established by careful histological evaluation to exclude RCC.

TREATMENT

Renal oncocytoma carries a good prognosis. The use of NSS for synchronous bilateral renal masses is highlighted.

CONCLUSION

NSS is recommended for renal oncocytoma wherever possible.

Pathology of ductal carcinoma in situ of the breast: a heterogeneous entity in need of greater understanding

Breast cancer is the commonest malignancy among Singapore women. Ductal carcinoma in situ (DCIS) is the putative precursor of the majority of invasive breast cancers, and its incidence has increased dramatically with mammographic screening. It is a heterogeneous disease--radiologically, pathologically and biologically. While the diagnosis of breast cancer in its pre-invasive phase, DCIS, allows the likelihood of cure with effective therapy, issues that surround its pathological heterogeneity are often not fully understood nor recognised. In this paper, the pathology and natural history of breast DCIS are reviewed; with emphasis on pathological classification schemes that attempt to predict recurrent disease or progression to invasive cancer. The potential role of biological markers is also evaluated. Atypical ductal hyperplasia, a lesion that is often difficult to distinguish from low grade DCIS; the significance and definition of microinvasion; and the value of fine needle aspiration cytology in DCIS are discussed. In addition, pathologic-radiologic correlations of local screen-detected cases of breast DCIS are presented. Awareness of the pathological parameters that impact on the biological behaviour of breast DCIS will enable appropriate management strategies; avoiding overtreatment in biologically indolent disease, while optimising adequate therapy for aggressive lesions.

Leiomyomatosis-like lymphangioleiomyomatosis of the colon in a female with tuberous sclerosis

Smooth muscle lesions of the large bowel, excluding the rectum, are generally rare, and diffuse smooth muscle lesions, termed leiomyomatosis, are even rarer. In this report, we document, for the first time, leiomyomatosis-like lymphangioleiomyomatosis (LAM) of the ascending, transverse, and descending colon in association with bilateral renal angiomyolipoma (AML) in a 30-year-old Chinese female with tuberous sclerosis complex (TSC). She presented with protracted constipation for which a colectomy was performed. Histology disclosed multiple confluent nodular CD34 and CD117 negative smooth muscle proliferation within the large bowel wall, whereas the renal biopsy revealed typical features of AML. Interestingly, the epithelioid smooth muscle cells of both the colonic and renal lesions were HMB45 positive, suggesting that leiomyomatosis-like LAM of the colon, pulmonary LAM and AML are closely related entities. The patient remained free of complications for the last five years after surgery. Leiomyomatosis-like LAM of the large bowel probably represents another manifestation of the tendency of TSC to be associated with proliferative lesions.

Case report: follicular adenoma in a thyroglossal duct remnant arising entirely within the hyoid bone

INTRODUCTION

We describe here the first reported case of a follicular adenoma arising from a thyroglossal duct remnant within the hyoid bone in Singapore.

CLINICAL PICTURE

A 32-year-old woman presented with an asymptomatic lump in the anterior midline of her neck of three months' duration. CT scan showed an expansile lesion localised to the medulla of the body of the hyoid.

TREATMENT

A well-defined intrahyoidal mass was found at surgery. Histology revealed a follicular adenoma arising from maldescended thyroid tissue within the hyoid bone.

OUTCOME

Recovery was uneventful.

CONCLUSION

It is important to consider thyroglossal duct carcinomas as a differential diagnosis when evaluating anterior neck lumps.

Correlation of nuclear morphometry with pathologic parameters in ductal carcinoma in situ of the breast

Morphometric features of nuclear perimeter, nuclear area, feret ratio, and feret circle were studied in a series of 64 cases of ductal carcinoma in situ (DCIS) of the breast in Singapore women. The results were compared with pathologic parameters of tumor size, nuclear grade, necrosis, cell polarization, and architectural pattern. There was statistically significant correlation between nuclear perimeter and area with all the pathologic parameters, with the strongest association observed for nuclear grade (P <.0001). Higher grade nuclei as assessed histologically were associated with larger nuclear area (44.14 microm(2) in low-grade lesions, 47.77 microm(2) in intermediate-grade lesions, and 72.05 microm(2) in high-grade lesions) and perimeter (25.94 microm in low-grade nuclei, 27.12 microm in intermediate-grade nuclei, and 33.66 microm in high-grade nuclei). DCIS lesions with necrosis and absence of polarization also revealed increased nuclear area and perimeter (P <.05). Comedo architecture was associated with larger nuclear area and perimeter (65.97 microm(2), 31.7 microm) than the papillary subtype (42.17 microm(2), 25.29 microm), with the mixed morphologic pattern disclosing intermediate values (54.83 microm(2), 29.43 microm). There was direct correlation for tumor size with nuclear area and perimeter (P <.01). No similar relationship was found between pathologic parameters and feret ratio or circle, indicating that nuclear roundness or lack of it did not factor as a significant component in the pathologic assessment.

Changes in the levels of nitric oxide synthase and protein kinase C gamma following kainic acid receptor activation in the rat spinal cord

In this study, we evaluated the levels of nitric oxide synthase, both neuronal and induced (nNOS and iNOS, respectively), cyclooxygenase-1 and 2 (COX-1 and COX-2) and protein kinase C gamma (PKCgamma) and correlated these with algogenic behavior following spinal kainic acid (KA) receptor activation in rats. Thirty adult male Sprague-Dawley rats were randomly assigned into six groups (n=5). Groups A, B, and C received 0.5 g kainic acid intrathecally and were analyzed at 3, 6, 24 h after injection, respectively. Groups D, E, and F received saline and were analyzed at 3, 6, 24 h after injection, respectively. We observed for behavioral changes in the rats following intrathecal KA injection and analyzed the protein levels of NOS, COX and PKCgamma by Western blotting techniques. Importantly, we clarified the potential roles of PKCgamma in the regulation of nNOS and COX-2 following intrathecal injection with KA in the rat spinal cord. COX-2 protein was detected but not significantly changed in the lumbosacral spinal cord at 3, 6, and 24 h following intrathecal KA injection (P>0.05). In contrast, nNOS protein was detected at higher levels in comparison with normal spinal cord at 6 and 24 h after intrathecal administration of KA (P<0.05). PKCgamma also increased significantly at 3, 6, and 24 h after intrathecal KA injection when compared with the baseline level (P<0.05). On the other hand, COX-1 and iNOS were not detected in either normal or KA treated spinal cords. These results provide strong in vivo evidence to support the idea that nNOS but not COX-2, plays an important role in spinal KA receptor activation. Furthermore, up-regulation of PKCgamma is involved in KA induced algogenic behavior in rats.

Extramammary Paget's disease of scrotum

We describe 4 cases of extramammary Paget's disease of the scrotum with underlying invasive carcinoma from 1997 to 1999. Three patients had metastatic inguinal lymphadenopathy. The delay in diagnosis was significant (mean 1 year). The diagnosis was made by skin biopsy in all patients. Histologically, intraepidermal cells with enlarged vesicular nuclei and vacuolated cytoplasm, which was mucin positive, were found. The mainstay of treatment is wide surgical excision, but positive margins remain a major problem. Other modes of treatment have been advocated but the efficacy for invasive disease is low. The key to successful control of the disease is therefore a high index of suspicion and early diagnosis.

Intrathecal bupivacaine with morphine or neostigmine for postoperative analgesia after total knee replacement surgery

PURPOSE

To compare the postoperative analgesic efficacy and safety of intrathecal (IT) neostigmine and IT morphine in patients undergoing total knee replacement under spinal anesthesia.

METHODS

Sixty patients scheduled for elective total knee replacement under spinal anesthesia were randomly divided into three equal groups which received IT 0.5% hyperbaric bupivacaine 15 mg with either normal saline 0.5 mL, neostigmine 50 microg, or morphine 300 microg. The maximal level of sensory block, duration of analgesia, time to use of rescue analgesics, the overall 24-hr and four-hour interval visual analogue scale (VAS) pain score, and the incidence of adverse effects were recorded for 24 hr after administration.

RESULTS

There was no significant difference in maximal level of sensory block among the three groups. The morphine group had a later onset of postsurgical pain and longer time to first rescue analgesics than the neostigmine group (P <0.05). Overall 24-hr VAS pain scores were significantly higher in the saline group vs the morphine and neostigmine groups (P <0.05). Motor block lasted significantly longer in the neostigmine group than in the morphine and saline groups (P <0.05). The incidence of adverse effects was similar in the neostigmine and morphine groups except for pruritus (70%) occurring more frequently in the morphine group than in the neostigmine and saline groups (0%; P <0.05). Overall satisfaction rates were better in the neostigmine group than in the morphine and saline groups (P <0.05).

CONCLUSIONS

IT neostigmine 50 microg produced postoperative analgesia lasting about seven hours with fewer side effects and better satisfaction ratings than IT morphine 300 microg.