Deep Vein Thrombosis and Healing Outcomes in Patients With Pyoderma Gangrenosum

This single-center prospective case-control study assessed the association between deep vein thrombosis and healing outcomes in patients with pyoderma gangrenosum.

Detection of neoplastic-immune hybrid cells with metastatic properties in uveal melanoma

Background

Uveal melanoma is the most common non-cutaneous melanoma and is an intraocular malignancy affecting nearly 7,000 individuals per year worldwide. Of these, approximately 50% will progress to metastatic disease for which there are currently no effective therapies. Despite advances in molecular profiling and metastatic stratification of uveal melanoma tumors, little is known regarding their underlying biology of metastasis. Our group has identified a disseminated neoplastic cell population characterized by co-expression of immune and melanoma proteins, circulating hybrid cells (hybrids), in patients with uveal melanoma. Compared to circulating tumor cells, which lack expression of immune proteins, hybrids are detected at an increased prevalence in peripheral blood and can be used as a non-invasive biomarker to predict metastatic progression.

Methods

To ascertain mechanisms underlying enhanced hybrid cell dissemination we identified hybrid cells within primary uveal melanoma tumors using single cell RNA sequencing and evaluated their gene expression and predicted ligand-receptor interactions in relation to other melanoma and immune cells within the primary tumor. We then verified expression of upregulated hybrid pathways within patient-matched tumor and peripheral blood hybrids using cyclic immunofluorescence and quantified their protein expression relative to other non-hybrid tumor and disseminated tumor cells.

Results

Among the top upregulated genes and pathways in hybrid cells were those involved in enhanced cell motility and cytoskeletal rearrangement, immune evasion, and altered cellular metabolism. In patient-matched tumor and peripheral blood, we verified gene expression by examining concordant protein expression for each pathway category: TMSB10 (cell motility), CD74 (immune evasion) and GPX1 (metabolism). Both TMSB10 and GPX1 were expressed on significantly higher numbers of disseminated hybrid cells compared to circulating tumor cells, and CD74 and GPX1 were expressed on more disseminated hybrids than tumor-resident hybrids. Lastly, we identified that hybrid cells express ligand-receptor signaling pathways implicated in promoting metastasis including GAS6-AXL, CXCL12-CXCR4, LGALS9-P4HB and IGF1-IGFR1.

Conclusion

These findings highlight the importance of TMSB10, GPX1 and CD74 for successful hybrid cell dissemination and survival in circulation. Our results contribute to the understanding of uveal melanoma tumor progression and interactions between tumor cells and immune cells in the tumor microenvironment that may promote metastasis.

Analysis of uveal melanoma scRNA sequencing data identifies neoplastic-immune hybrid cells that exhibit metastatic potential

Uveal melanoma (UM) is the most common non-cutaneous melanoma and is an intraocular malignancy that affects nearly 7,000 individuals per year worldwide. Of these, nearly 50% will progress to metastatic disease for which there are currently no effective therapies. Despite advances in the molecular profiling and metastatic stratification of class 1 and 2 UM tumors, little is known regarding the underlying biology of UM metastasis. Our group has identified a disseminated tumor cell population characterized by co-expression of immune and melanoma proteins, (circulating hybrid cells (CHCs), in patients with UM. Compared to circulating tumor cells, CHCs are detected at an increased prevalence in peripheral blood and can be used as a non-invasive biomarker to predict metastatic progression. To identify mechanisms underlying enhanced hybrid cell dissemination we sought to identify hybrid cells within a primary UM single cell RNA-seq dataset. Using rigorous doublet discrimination approaches, we identified UM hybrids and evaluated their gene expression, predicted ligand-receptor status, and cell-cell communication state in relation to other melanoma and immune cells within the primary tumor. We identified several genes and pathways upregulated in hybrid cells, including those involved in enhancing cell motility and cytoskeleton rearrangement, evading immune detection, and altering cellular metabolism. In addition, we identified that hybrid cells express ligand-receptor signaling pathways implicated in promoting cancer metastasis including IGF1-IGFR1, GAS6-AXL, LGALS9-P4HB, APP-CD74 and CXCL12-CXCR4. These results contribute to our understanding of tumor progression and interactions between tumor cells and immune cells in the UM microenvironment that may promote metastasis.

Relevance of circulating hybrid cells as a non-invasive biomarker for myriad solid tumors

Metastatic progression defines the final stages of tumor evolution and underlies the majority of cancer-related deaths. The heterogeneity in disseminated tumor cell populations capable of seeding and growing in distant organ sites contributes to the development of treatment resistant disease. We recently reported the identification of a novel tumor-derived cell population, circulating hybrid cells (CHCs), harboring attributes from both macrophages and neoplastic cells, including functional characteristics important to metastatic spread. These disseminated hybrids outnumber conventionally defined circulating tumor cells (CTCs) in cancer patients. It is unknown if CHCs represent a generalized cancer mechanism for cell dissemination, or if this population is relevant to the metastatic cascade. Herein, we detect CHCs in the peripheral blood of patients with cancer in myriad disease sites encompassing epithelial and non-epithelial malignancies. Further, we demonstrate that in vivo-derived hybrid cells harbor tumor-initiating capacity in murine cancer models and that CHCs from human breast cancer patients express stem cell antigens, features consistent with the potential to seed and grow at metastatic sites. Finally, we reveal heterogeneity of CHC phenotypes reflect key tumor features, including oncogenic mutations and functional protein expression. Importantly, this novel population of disseminated neoplastic cells opens a new area in cancer biology and renewed opportunity for battling metastatic disease.

Measure Twice: Promise of Liquid Biopsy in Pediatric High-Grade Gliomas

Purpose

To review and critique the current state of liquid biopsy in pHGG.

Materials and Methods

Published literature was reviewed for articles related to liquid biopsy in pediatric glioma and adult glioma with a focus on high-grade gliomas.

Results

This review discusses the current state of liquid biomarkers of pHGG and their potential applications for liquid biopsy development.

Conclusions

While nascent, the progress toward identifying circulating analytes of pHGG primes the field of neuro-oncoogy for liquid biopsy development.

Cell Adhesion Molecule CD166/ALCAM Functions Within the Crypt to Orchestrate Murine Intestinal Stem Cell Homeostasis

BACKGROUND & AIMS

Intestinal epithelial homeostasis is maintained by active-cycling and slow-cycling stem cells confined within an instructive crypt-based niche. Exquisite regulating of these stem cell populations along the proliferation-to-differentiation axis maintains a homeostatic balance to prevent hyperproliferation and cancer. Although recent studies focus on how secreted ligands from mesenchymal and epithelial populations regulate intestinal stem cells (ISCs), it remains unclear what role cell adhesion plays in shaping the regulatory niche. Previously we have shown that the cell adhesion molecule and cancer stem cell marker, CD166/ALCAM (activated leukocyte cell adhesion molecule), is highly expressed by both active-cycling Lgr5⁺ ISCs and adjacent Paneth cells within the crypt base, supporting the hypothesis that CD166 functions to mediate ISC maintenance and signal coordination.

METHODS

Here we tested this hypothesis by analyzing a CD166^-/- mouse combined with immunohistochemical, flow cytometry, gene expression, and enteroid culture.

RESULTS

We found that animals lacking CD166 expression harbored fewer active-cycling Lgr5⁺ ISCs. Homeostasis was maintained by expansion of the transit-amplifying compartment and not by slow-cycling Bmi1⁺ ISC stimulation. Loss of active-cycling ISCs was coupled with deregulated Paneth cell homeostasis, manifested as increased numbers of immature Paneth progenitors due to decreased terminal differentiation, linked to defective Wnt signaling. CD166^-/- Paneth cells expressed reduced Wnt3 ligand expression and depleted nuclear β-catenin.

CONCLUSIONS

These data support a function for CD166 as an important cell adhesion molecule that shapes the signaling microenvironment by mediating ISC-niche cell interactions. Furthermore, loss of CD166 expression results in decreased ISC and Paneth cell homeostasis and an altered Wnt microenvironment.

Synthesis, spectroscopic, thermal and antimicrobial studies of neodymium(III) and samarium(III) complexes derived from tetradentate ligands containing N and S donor atoms

Trivalent lanthanide complexes of the type [Ln(L)Cl(H2O)2] (where Ln=Nd(III) or Sm(III) and LH2=Schiff bases derived by the condensation of 3-(phenyl/substitutedphenyl)-4-amino-5-mercapto-1,2,4-triazole with diacetyl/benzil) have been synthesized by the reactions of anhydrous lanthanide(III) chloride with Schiff bases in methanol. The structures of the complexes have been proposed on the basis of elemental analysis, electrical conductance, magnetic moment, spectroscopic measurements (IR, 1H, 13C NMR and UV-vis spectra) and X-ray diffraction studies. The spectral data reveal that the Schiff base ligands behave as dibasic tetradentate chelating agents having coordination sites at two thiol sulfur atoms and two azomethine nitrogen atoms. The presence of coordinated water in metal complexes was confirmed by thermal and IR data of the complexes. All the Schiff bases and their metal complexes have also been screened for their antibacterial activity against Bacillus subtilis, Staphylococcus aureus and antifungal activities against Aspergillus niger, Curvularia pallescens and Colletotrichum capsici.

Synthesis, spectral characterization and antimicrobial studies of nano-sized oxovanadium(IV) complexes with Schiff bases derived from 5-(phenyl/substituted phenyl)-2-hydrazino-1,3,4-thiadiazole and indoline-2,3-dione

A new class of oxovanadium(IV) complexes with Schiff bases derived by the condensation of 5-(phenyl/substituted phenyl)-2-hydrazino-1,3,4-thiadiazoles and indoline-2,3-dione have been prepared in ethanol in the presence of sodium acetate. Micro-analytical data, magnetic susceptibility, UV-Vis, IR, EPR and XRD spectral techniques were used to confirm the structures. Electronic absorption spectra of the complexes suggest a square-pyramidal geometry. The oxovanadium(IV) complexes have monoclinic crystal system and particle sizes were found to be in the range 18.0 nm to 24.0 nm (nano-size). In vitro antifungal activity of synthesized compounds was determined against fungi Aspergillus niger, Colletotrichum falcatum and Colletotrichum pallescence and in vitro antibacterial activity was determined by screening the compounds against Gram-negative (Escherichia coli and Salmonella typhi) and Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacterial strains. The oxovanadium(IV) complexes have higher antimicrobial effect than free ligands.

Synthesis, spectral and antimicrobial activity of Zn(II) complexes with Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and benzaldehyde/2-hydroxyacetophenone/indoline-2,3-dione

Zn(II) complexes have been synthesized by reacting zinc acetate with Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and 2-hydroxyacetophenone/benzaldehyde/indoline-2,3-dione. All these complexes are soluble in DMF and DMSO; low molar conductance values indicate that they are non electrolytes. Elemental analyses suggest that the complexes have 1:2 metal to ligands stoichiometry of the types [ZnL2(H2O)2](L=monoanionic Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and 2-hydroxyacetophenone/indoline-2,3-dione) [ZnL2(')(OOCCH3)2(H2O)2](L'=neutral Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and benzaldehyde), and they were characterized by IR, (1)H NMR, and (13)C NMR. Particle sizes of synthesized compounds were measured with dynamic light scattering (DLS) analyser which indicates that particle diameter are of the range ca. 100-200nm. All these Schiff bases and their complexes have also been screened for their antibacterial (Bacillus subtilis (B. subtilis), Escherichia coli (E. coli) and antifungal activities (Colletotrichum falcatum (C. falcatum), Aspergillus niger (A. niger), Fusarium oxysporium (F. oxysporium) Curvularia pallescence (C. pallescence). The antimicrobial activities have shown that upon complexation the activity increases.

Template synthesis, spectroscopic characterization and preliminary insulin-mimetic activity of oxovanadium(IV) complexes with N₂O₂ diazadioxa macrocycles

A new series of diazadioxa oxovanadium(IV) macrocyclic complexes of type [VO(mac)]SO(4) have been synthesized via the condensation reaction of a 3-(phenyl/substituted phenyl)-4-amino-5-hydrazino-1,2,4-triazole (H(2)L) with salicylaldehyde/2-hydroxyacetophenone and 1,4-dibromobutane in the presence of oxovanadium(IV) sulfate in ethanol. All the newly synthesized compounds were characterized on the basis of elemental analyses, conductance measurements, magnetic properties, spectral (UV-Vis, IR, EPR) and XRD studies. The particle size of the complexes has been calculated from XRD spectra using Debye-Scherrer formula and these are found to be in 31-32 nm range. The efficacy of two macrocyclic complexes was also studied in streptozotocin-induced diabetic rats over a period of 30 days. The administration of these complexes in diabetic rats reversed the diabetic effect due to their insulin-mimetic effects.

Synthesis, spectral characterization and biological activity of zinc(II) complexes with 3-substituted phenyl-4-amino-5-hydrazino-1, 2, 4-triazole Schiff bases

New Zn(II) complexes have been synthesized by the reactions of zinc(II) acetate with Schiff bases derived from 3-substituted phenyl-4-amino-5-hydrazino-1, 2, 4-triazole and benzaldehyde, 2-hydroxyacetophenone or indoline-2,3-dione. All these complexes are soluble in DMF and DMSO; low molar conductance values indicate that they are non-electrolytes. Elemental analyses suggest that the complexes have 1:1 stoichiometry of the type [ZnL(H(2)O)(2)], [ZnL'(OAc)(2)(H(2)O)(2)] (L=dianionic Schiff bases derived from 3-(substituted phenyl)-4-amino-5-hydrazino-1, 2, 4-triazole and 2-hydroxyacetophenone or indoline-2,3-dione; L'=neutral Schiff bases derived from 3-(substituted phenyl)-4-amino-5-hydrazino-1, 2, 4-triazole and benzaldehyde) and they were characterized by FT-IR, (1)H NMR, (13)C NMR and FAB mass. All these Schiff bases and their complexes have also been screened for their antibacterial activities against Bacillus subtilis, Escherichia coli and antifungal activities against Colletotrichum falcatum, Aspergillus niger, Fusarium oxysporium and Carvularia pallescence by petriplates methods.

Organophosphorus derivatives containing isatin-3-hydrazones as chemotherapeutants against fungal pathogens of sugarcane

A total of 20 novel organophosphorus derivatives have been synthesized by the reactions of O,O-diethylchlorophosphate/thiophosphate with isatin-3-(substituted benzoic acid/phenoxy acetic acid hydrazones). The derivatives have been characterized on the basis of analysis and spectral (IR and (1)H and (13)C NMR) data. Fungicidal activities of the derivatives against Colletotrichum falcatum , Fusarium oxysporum , and Curvularia pallescence have been evaluated. The screening results have been correlated with the structural features of the tested compounds. The greater potency has been observed with thiophosphates compared to phosphates, with substituted phenoxy acetic acid hydrazones compared to substituted benzoic acid hydrazones, and with substitutent Cl(-) attached to the aromatic ring compared to other substitutents. O,O-Diethylchlorophosphate compounds containing isatin-3-(4-chlorophenoxy acetic acid hydrazone) (IIe) and the compound containing two molecules of O,O-diethylchlorophosphate attached to isatin-3-(4-hydroxy phenoxy acetic acid) hydrazone (IIh) were proven to be more active than some prevalent commercial synthetic fungicides.

Synthesis, spectroscopic, thermal and antifungal studies on lanthanum(III) and praseodymium(III) derivatives of 1,1-diacetylferrocenyl hydrazones

A series of new coordination complexes of La(III) and Pr(III) with hydrazones, derived from 1,1-diacetylferrocene and different aromatic acid hydrazides have been synthesized and characterized by elemental analyses, electrical conductance, magnetic moment, IR, (1)H NMR, UV-vis spectra and molar conductance. The thermal behaviour of the complexes under non-isothermal condition was investigated by TG and DTG techniques. The antifungal activity of hydrazones and their corresponding complexes were also investigated.

Real-time holographic deconvolution techniques for one-way image transmission through an aberrating medium: characterization, modeling, and measurements

We propose and demonstrate a new photorefractive real-time holographic deconvolution technique for adaptive one-way image transmission through aberrating media by means of four-wave mixing. In contrast with earlier methods, which typically required various codings of the exact phase or two-way image transmission for correcting phase distortion, our technique relies on one-way image transmission through the use of exact phase information. Our technique can simultaneously correct both amplitude and phase distortions. We include several forms of image degradation, various test cases, and experimental results. We characterize the performance as a function of the input beam ratios for four metrics: signal-to-noise ratio, normalized root-mean-square error, edge restoration, and peak-to-total energy ratio. In our characterization we use false-color graphic images to display the best beam-intensity ratio two-dimensional region(s) for each of these metrics. Test cases are simulated at the optimal values of the beam-intensity ratios. We demonstrate our results through both experiment and computer simulation.

Photoconductive optically driven deformable membrane under high-frequency bias: fabrication, characterization, and modeling

The fabrication and characterization of an optically addressable deformable mirror for a spatial light modulator are described. Device operation utilizes an electrostatically driven pixelated aluminized polymeric membrane mirror supported above an optically controlled photoconductive GaAs substrate. A 5 mum thick grid of patterned photoresist supports the 2 mum thick aluminized Mylar membrane. A conductive ZnO layer is placed on the backside of the GaAs wafer. Similar devices were also fabricated with InP. A standard Michelson interferometer is used to measure mirror deformation data as a function of illumination, applied voltage, and frequency. The device operates as an impedance distribution between two cascaded impedances of deformable membrane substrate, substrate, and electrode. An analysis of device's operation under several bias conditions, which relates membrane deformation to operating parameters, is presented.

Optically driven microelectromechanical-system deformable mirror under high-frequency AC bias

A new, optically addressed deformable mirror device is demonstrated. The device consists of a pixellated metalized polymeric membrane mirror supported above an optically addressed photoconductive substrate. A conductive transparent ZnO layer is deposited on the back side of the substrate. A very high-frequency AC bias is applied between the membrane and the back electrode of the device. The membrane is deformed when the back of the device is illuminated because of impedance and bias redistribution between two cascaded impedances. We fabricated, demonstrated, and modeled the operation of this device.

Organophosphorus derivatives containing piperazine dithiosemicarbazones as chemotherapeutants against fungal pathogens of sugarcane

Five novel organophosphorus derivatives have been synthesized by the reactions of O,O-diethylchlorophosphate with piperazine dithiosemicarbazones. The derivatives have been characterized on the basis of analyses and spectral (IR, 1H NMR) data. Fungicidal activities of these derivatives against Colletotrichum falcatum, Fusarium oxysporum, and Curvularia pallescence have been evaluated. The screening results have been correlated with the structural features of the tested compounds. Organophosphorus derivatives containing 1,4-bis(4-chlorobenzaldehyde)piperazine dithiosemicarbazone and 1,4-bis(4-methoxybenzaldehyde)piperazine dithiosemicarbazone proved to be more active than some prevalent commercial synthetic fungicides.

Promoting, building and sustaining a regional laboratory network in a changing environment

The Queen's University Department of Pathology and its affiliated hospital laboratories (Kingston, Canada) have operated a successful laboratory outreach program for more than a decade in Southeastern Ontario. The outreach program provides high quality reference testing and technical and professional expertise in laboratory medicine to largely rural and small urban community hospitals. As a consequence of dramatic cuts to the publicly funded health-care system in the Province of Ontario, the environment in which laboratory medicine is practiced has altered irrevocably. This article discusses some of the difficult internal and external challenges faced by the outreach program within the region and how they were effectively managed, not only to maintain but to enhance the program's services. The result has been a continued improvement in the quality of laboratory services in the region with significantly increased cost-effectiveness, largely through reengineering and consolidation.

Adult head and neck lymphomas in Papua New Guinea: a retrospective study of 70 cases

BACKGROUND

During a 10-year period (1986-95), 70 adult Papua New Guineans with head and neck lymphomas were seen in the 18 years-and-above age group.

METHODS

The clinical information was obtained from the medical records section of the Port Moresby General Hospital. Relevant treatment modalities and the follow-up data were acquired from the National Cancer Centre, Angau Memorial Hospital, Lae.

RESULTS

Of a total of 227 adult lymphomas recorded in a 10-year period, 70 cases were seen in the head and neck region. Non-Hodgkin's lymphoma constituted 56 cases, which included seven cases of adult Burkitt's-like lymphoma. Fourteen cases of Hodgkin's lymphoma were recorded.

CONCLUSIONS

In Papua New Guinea, malignant lymphomas primarily affecting the head and neck region were seen in 30.8% of all lymphomas. This constitues 2.8% of all malignancies in this region. These lymphomas appear to be more aggressive at this site. Proper tissue diagnosis and combination chemoradiotherapy are the key factors in its management.

Paediatric head and neck lymphomas in Papua New Guinea: a review and analysis of 67 cases

A retrospective study of head and neck lymphomas in Papua Newguinean children between the age of 0 and 12 years for a 10-year period has been attempted. A total of 67 cases are recorded. This constitutes approximately 23% of all lymphomas seen during this period. There was a male predominance in all groups. Non-Hodgkin's lymphomas (NHL) comprised of 92% of which Burkitt's lymphomas (BL) predominate (64%). Almost 50% of these cases seen were in the age group of 5-8 years. In BL, cheek swelling and upper jaw involvement are the common modes of presentation, however, in 23% of cases advanced disease with multiple sites of involvement are noted. In other NHL cases, approximately 55% presented with cervical lymphadenopathy only, maxillary sinus was affected in four cases and orbit in two cases. Histological evaluation of NHL cases excluding BL revealed two high grade, nine intermediate grade and seven low grade tumours. Hodgkin's lymphoma (HL) comprised of 8%. All cases of HL presented with cervical lymphadenopathy. Standard therapeutic modalities for lymphomas with multidrug chemotherapy, surgery and radiotherapy were followed. Proper prognostic evaluation following the treatment had not been possible in view of poor patient compliance and lack of follow up.

Integrating academic and community laboratory needs: developing a successful outreach program

Remarkably few large regional laboratory programs involving academic health centers exist in Canada. We present a model of a successful laboratory outreach program established by the Queen's University Department of Pathology (Kingston, Ontario) and its affiliated hospital laboratories. Community hospitals in small urban and semi-rural areas benefit from a diffusion of specialty expertise in laboratory medicine and technology, which enables them to increase their local testing capabilities and improve turn-around time. Testing and services of a more complex nature are referred to the academic hospitals. The result has been a steady improvement in the quality of laboratory services in the region with increased cost-effectiveness through shared services and focused economies of scale.

Cystic lesions of the nasal cavity and the paranasal sinuses: report of two unusual cases

The clinicopathological features of two unusual cystic lesions, one arising in the nose, a calcified mucocele or a calcified retention cyst and the other in the maxillary sinus, a dentigerous cyst originating in a supernumerary tooth, are described. The literature on these two rare lesions is briefly reviewed.

Intestinal infarction in systemic lupus erythematosus--report of a case with an unusual obliterative vascular lesion

Intestinal infarction is a rare complication of systemic lupus erythematosus (SLE). A 26-year-old Papua New Guinean female who developed such a complication and underwent emergency laparotomy is described. The pathological changes in the mesenteric vessels and possible pathogenetic mechanisms are discussed. The relevant literature is briefly reviewed.

Nasopharyngeal osteosarcoma as second malignant neoplasm in a post-treated unilateral retinoblastoma: report of a case and review of literature

A rare case of osteosarcoma primarily originating in the nasopharynx of an 11-year-old Papua New Guinean female who received irradiation and multi-agent chemotherapy for unilateral non-hereditary retinoblasma is described. The relevant literature is briefly reviewed. The complex role of radiation, cytotoxic drugs and genes in the development of a second malignant neoplasm in association with retinoblasma is also discussed.

Heterogeneity within the Epstein-Barr virus nuclear antigen 2 gene in different strains of Epstein-Barr virus

DNA isolated from biopsies of endemic Burkitt's lymphoma (BL) from New Guinea was analysed for the presence of Epstein-Barr virus (EBV) sequences using the polymerase chain reaction. Primers were designed to amplify sequences within the Epstein-Barr virus nuclear antigen (EBNA) 1 and 2 genes. These analyses detected the EBNA1 sequence in all the biopsies studied. Additional sets of primers directed against the EBNA2 gene were used in order to categorize the EBV strains as A-type or B-type (39% A-type; 50% B-type; 5% A- and B-type; 5% untypeable). These results indicated that DNA sequence heterogeneity within the EBNA2 gene region may exist in different strains of EBV. The extent of DNA sequence heterogeneity among different strains of EBV was determined by sequencing of a region within the EBNA2 gene in a number of different A-type and B-type strains of EBV originating from Africa or New Guinea. The results demonstrated DNA sequence heterogeneity within the EBNA2 gene in different strains of EBV. This heterogeneity was more extensive among A-type strains than B-type strains of EBV.

Surgical thyroid disease in Papua New Guinea

A clinical and histopathological analysis was carried out on 376 thyroid specimens removed under various diagnoses from the surgical clinics of Papua New Guinea over a period of 11 years (1980-90). Solitary nodular goitre (solid and cystic) was the most common clinical diagnosis. Nineteen per cent of the solid and 35% of the cystic solitary nodular goitres were found to be malignant. Malignant goitres were confirmed histologically in 73.3% of the clinically diagnosed cases of malignancy. The presence of amyloid goitre (1.9%) posed a significant diagnostic and therapeutic problem due to its clinical features resembling that of malignant goitre. Hemithyroidectomy (lobectomy) was the most common surgical procedure employed for all unilateral thyroid lesions and partial or subtotal thyroidectomy was performed for benign and most malignant lesions.

The spectrum of cancer in Papua New Guinea. An analysis based on the Cancer Registry 1979-1988

Malignant tumors registered with the Tumour Registry of Papua New Guinea (PNG) from 1958-1988 were analyzed with emphasis on the variation of incidence with time and different regions. Cancer incidence was generally low in PNG. During this period, carcinoma of oral cavity, cervix, breast, and skin, hepatoma, and lymphoma were the most common types of malignant lesions detected. The incidence of carcinoma of the oral cavity has increased. Currently, it is more common in the Highlands region and is associated with the spread of betel nut chewing. A threefold increase in cervical carcinoma registration was observed nationally, with a sixfold increase in the Highlands region; this was attributed both to social changes and improved registration. The incidence of breast cancer has doubled, in keeping with better registration, but there is little interregional variation. The decline in registrations of hepatocellular carcinoma is artifactual. PNG is a high-incidence area for Burkitt lymphoma, but Hodgkin disease is rare. Both Burkitt and other non-Hodgkin lymphomas are uncommon in the Highlands. A decline in the incidence of squamous carcinoma of skin was observed that was associated with improved control of tropical ulcers. The incidence of stomach cancer is falling. The registered cancer incidence in PNG is low, even when compared with that in native people from other Pacific nations, such as Fijians and New Caledonian Melanesians. Preventive measures have been hitherto ineffective, with the exception of squamous carcinoma of skin.

Gastric stenosis following the ingestion of car battery acid

The acute consequences of the ingestion of corrosive substances include acute necrosis of the upper gastrointestinal tract, haemorrhage and perforation. Late complications include the development of stenotic lesions. A case of fibrous gastric stenosis following the ingestion of car battery acid is presented. Endoscopically, the appearances were consistent with gastric carcinoma.

Seat-belt message and the law?

This paper attempts to draw together available information on the use of seat belts, one of the most important safety devices for a person in a car. Considering the high rate of mortality and morbidity due to road traffic accidents in Papua New Guinea the authors strongly feel that seat-belt usage should be made compulsory. When one looks at the history of the implementation of such a successful countermeasure in other countries it seems that legislation is the only answer.

Studies on some iridium(III) complexes with Schiff bases derived from amino carboxylic acids

The reactions of iridium(III) chloride with different Schiff bases gave complexes of types [Ir(SB)3], [Ir(SB')Cl(H2O)2], [Ir(SB'')Cl2]n, [Ir(SB'' ')Cl(H2O)]n (SBH = Schiff bases derived from anthranilic acid and benzaldehyde, acetophenone, vanillin, cinnamaldehyde or m-hydroxyacetophenone; SB'H2 = Schiff bases derived from anthranilic acid and salicylaldehyde or o-hydroxyacetophenone; SB''H = Schiff bases derived from p-aminobenzoic acid and benzaldehyde, acetophenone, vanillin, cinnamaldehyde, or m-hydroxyacetophenone; SB'' 'H2 = Schiff bases derived from p-aminobenzoic acid and salicylaldehyde or o-hydroxyacetophenone). These complexes have been characterized on the basis of elemental analyses, conductance, magnetic moment, and spectral (electronic, i.r., and 1H n.m.r.) data. The electronic spectra reveals octahedral geometry for these complexes except for [Ir(SB'')Cl2]n, which is trigonal bipyramidal. The thermal behavior of these complexes has also been studied by TG, DTG, and DSC techniques. The different kinetic parameters, viz., order of reaction, activation of energy, and heat of reaction were calculated. The antifungal and antiviral activities of the complexes with Schiff bases derived from anthranilic acid have also been investigated.

Childhood malignant tumours in Papua New Guinea

Data from the Papua New Guinea Tumour Registry and the Central Pathology Department were reviewed in order to document the incidence and pattern of malignancies in children in Papua New Guinea. Altogether, 680 cases of histologically defined childhood malignancies were recorded during the 14.5 years from 1971 to 1985. The frequencies of the various tumours were compared with past data and with published data from other countries. The incidence of malignancies in Papua New Guinean children appeared to be low, 36.5/1,000,000/year, with a male:female ratio of 1.6:1. Lymphoma was the most commonly occurring tumour and Burkitt's tumour accounted for 53% in this group. The relative frequency of leukaemia compared with lymphoma appeared to have increased since a previous report. A relatively high incidence of retinoblastoma (6.9%) and of other embryonal tumours (4.8%) was recorded, whilst the recorded incidences of tumours of the central nervous system (3.8%) and neuroblastoma (3.7%) were low. Ewing's sarcoma accounted for almost half of the bone tumours, whilst Kaposi's sarcoma was a relatively frequent soft tissue tumour. Differences and similarities between the Papua New Guinea data and those from other countries are discussed.

Enantiomers of 7-(2,3-epoxypropoxy)actinomycin D as dual-action DNA-acting antitumor agents

Enantiomeric forms of (+/-)-EPA [racemic 7-(2,3-epoxypropoxy)actinomycin D] have been synthesized; these are (R)-(+)- and (S)-(-)-EPA, which are active against a range of actinomycin resistant and marginally responsive tumors. The R-(+) enantiomer is uniformly superior to the other forms in all the tumor lines tested. These enantiomers act by binding to DNA, both by intercalation and alkylation at the guanine base of DNA. They are superior to actinomycin D in their in vitro activity against mouse leukemias (L1210 and P388/ADR) and mouse melanoma B16. This superior activity is also evident against all the preceding mouse leukemias and against solid tumors B16 and C26 in vivo. In biochemical action, the enantiomers behave similarly and act primarily by inhibiting DNA synthesis in tumor cells; the only difference found was in their preference for sites in DNA bases during alkylation. The R-(+) enantiomer generates an adduct that is believed to be bonded to the N7-site of guanosine; conversely, the S-(-) isomer forms two adducts with DNA that are different from the preceding one by HPLC and are tentatively assigned O6-guanosine-substituted structures on the basis of their UV, CD, and other chemical behaviors.

New actinomycin D analogues as superior chemotherapeutic agents against primary and advanced colon tumors and colon xenografts in nude mice

"Reverse" analogues (RAD's) of actinomycin D (AMD) and their antitumor activity against mouse and human colon tumor cells are reported. RAD's are tetracyclic, and they have an oxazole ring fused on the tricyclic phenoxazine chromophore of AMD. The oxazole ring in RAD is substituted at the C-2 carbon with either a CH3 (in RAD I), a C6H5 (in RAD II), or a CH2CONH(CH2)4NH2 (in RAD III) group. In tumor cells and rat hepatic microsomes, RAD's are metabolized to a tricyclic "symmetrical" analogue of AMD (SAD) with the loss of the oxazole ring and its substituents. RAD and SAD are very active in priming superoxides in the presence of microsomal enzymes as well as in inhibiting the synthesis of DNA and the growth of human colon tumor HT-29 cells in vitro. RAD III and SAD efficiently cleave closed circular plasmid pBR322 DNA like the antitumor agent bleomycin. In addition to their strong inhibitory activity against P388 and B16 tumors in vitro and in vivo, RAD III and SAD demonstrate high levels of activity against primary C26 and advanced C38 colon tumors in mice and against a xenograft of human colon adenocarcinoma CX-1 in athymic mice. In all these biological activities, the analogues demonstrate superiority to AMD in several experimental tumors. Also, the analogues, in contrast to AMD, show reduced toxicity in tumor-free mice, which is possibly due to the metabolic deactivation of SAD in host organs.

Synthesis and biological properties of actinomycin D chromophoric analogues substituted at carbon 7 with aziridine and cyclopropyl functions

The growing importance of functionalized tricyclic rings, e.g., cyclopropyl and aziridine, in numerous organic biomolecules led us to develop syntheses of novel actinomycin D (AMD) analogues substituted with aziridine and cyclopropyl functions. Reaction of 7-hydroxyactinomycin D with 1-aziridineethyl iodide and bromomethylcycloporopane afforded the desired 7-[2-(1-aziridinyl)ethoxy] and cyclopropylmethoxy analogues, respectively. Calf thymus DNA binding of these analogues was comparable to that of AMD as examined by UV-vis difference spectral measurements, CD techniques, and relaxation of supercoiled closed circular SV40 DNA, indicating an intercalative mode of binding to the DNA duplex. Thermal denaturation of DNA experiments employing higher temperatures than room temperature exhibit a thermal lability of the DNA analogue complexes, suggestive of a probable covalent bond formation with DNA bases. The analogues were found to be 1/4-1/40 as cytotoxic to human lymphoblastic CCRF-CEM leukemia and B16 melanoma cells in vitro as AMD, with ID50 values in the nanomolar concentration range.

Fibrocalculous pancreatic diabetes in Papua New Guinea

Fibrocalculous pancreatic diabetes of the tropics has not been previously identified in Papua New Guinea where the prevalence of Type 2 (non-insulin-dependent) diabetes is increasing. Four patients with this syndrome:--onset of diabetes before the age of 30 years, low body mass index, radiologic pancreatic calcification and marked hyperglycaemia with resistance to ketosis were recognized over three years at Port Moresby General Hospital. Two patients had a history of recurrent abdominal pain in childhood, and two patients had documented insulin requirement greater than 1.5 U/kg daily, and insulin resistance confirmed by intravenous insulin tolerance test. Plasma C-peptide was present in the three cases tested. In the two patients tested islet cell antibodies were not detected but in both there was a prominent diffuse acinar stain suggestive of antibodies to acinar tissue.

Ovarian neoplasms in children and adolescents in Papua New Guinea

A study of ovarian tumours in young females under the age of 20 years in Papua New Guinea between the period 1976-1986 is presented. During these 11 years a total of 101 cases was seen among 802 ovarian tumours reported in all age groups. Epithelial tumours comprised the largest number (66.3%) followed by germ cell tumours (24.8%). Ten patients (9.9%) presented with torsion. Only 3 (3%) cases of Burkitt lymphoma were recorded (3%); the series included 1 case of primary non-gestational choriocarcinoma of the ovary in an 11-year-old premenarchal girl.

Synthesis and biological properties of actinomycin D chromophoric analogues substituted at the 7-carbon with aziridine and aminopropoxy functions

The growing importance of functionalized aziridines in numerous organic biomolecules led us to develop syntheses of novel actinomycin D (AMD) analogues substituted with an aziridine. Reaction of 7-hydroxyactinomycin D with 2-(iodomethyl)aziridine produced the desired 7-(2-aziridinylmethoxy)actinomycin analogue. In an attempt to develop an alternate route to this analogue, 7-(2-azido-3-iodopropoxy)actinomycin was subjected to reduction with dimethylamine-borane complex; the reaction did not produce the three-membered aziridine; instead the reaction product was found to be linear 7-(2-aminopropoxy)actinomycin D. Calf-thymus-DNA binding of these analogues was comparable to that of AMD as examined by UV-visible difference spectral measurements, thermal denaturation of DNA, and CD techniques. The analogues were found to be about 1/4 to 1/30 as cytotoxic to human lymphoblastic CCRF-CEM leukemia and B16 melanoma cells in vitro as AMD.

Childhood Kaposi's sarcoma in Papua New Guinea

In the country of Papua New Guinea, with its diverse population of nearly 3 million people, some disease patterns have a strange similarity to those seen in tropical Africa. Kaposi's sarcoma is a condition which is commonly seen in adult males; childhood Kaposi's sarcoma is relatively uncommon. Six cases, all males, aged from 6 months to 12 years have been detected since 1978. The primary organ involvement included skin in four cases, oral cavity in one case and lymph node in one case. The varied clinico-pathological features are described. This is the first report of such cases from Papua New Guinea.

DNA-binding abilities of bisguanylhydrazones of anthracene-9,10-dicarboxaldehyde

DNA-binding strengths of three anthracene-9,10-dicarboxaldehyde hydrazones were examined by spectral shifts of the drug-DNA combinations, spectral titration by Scatchard plots, elevation of DNA melting temperature during complexation and comparison of spectral shifts in the presence of DNA's having variable base contents. Dissociation of the DNA-complexes was also observed. The results showed a strong degree of binding by the three compounds. They did not exhibit noticeable base-pair specificity, but both associated with and dissociated rapidly from DNA. Scatchard plots for DNA association indicated two types of binding; the stronger was most likely due to intercalation of the planar anthracene ring into the DNA double helix. No direct correlation can be drawn between the observed anti-cancer activities and DNA binding affinities of these compounds in vitro.

Enzymic and chemical reduction of 2-deaminoactinomycins to free radicals

The antitumour activity of actinomycin D (AMD) has been proposed to result, in part, from its intercalation into DNA dG-dC base-pairs leading to an inhibition of RNA synthesis. We have recently prepared 2-deamino-2-nitroactinomycin D and 2-deamino-actinomycin D and determined that, unlike AMD, these analogues do not intercalate into calf-thymus DNA. In the present study we show that these analogues and their corresponding peptide-free diethylamino derivatives are more effective than the parent AMD in forming ion radicals, in stimulating oxygen uptake and in forming superoxide anion when incubated in the presence of NADPH and NADPH cytochrome P-450 reductase. NaBH4-mediated reduction of these compounds yielded free radicals as shown by electron paramagnetic resonance (e.p.r.) spectroscopy. Free radicals could also be generated by incubation of these actinomycins with NADPH and either liver microsomes or purified NADPH cytochrome P-450 reductase. In the presence of molecular oxygen these free radicals spontaneously reoxidized by transfer of a single electron to molecular oxygen to form superoxide. Relative rates of superoxide formation were established for these substrates with the 2-deamino-2-nitroactinomycin D exhibiting the highest activity. It is proposed that the antitumour activity of these AMD analogues results, in part, from their ability to form reactive reduced oxygen species and, as such, these actinomycin derivatives may serve as useful probes for the tumouricidal mechanism of this family of agents.