Removal of basic and reactive dyes using ethylenediamine modified rice hull.

Wastewaters from textile industries may contain a variety of dyes that have to be removed before their discharge into waterways. Rice hull, an agricultural by-product, was modified using ethylenediamine to introduce active sites on its surface to enable it to function as a sorbent for both basic and reactive dyes. The sorption characteristics of Basic Blue 3 (BB3) and Reactive Orange 16 (RO16) by ethylenediamine modified rice hull (MRH) were studied under various experimental conditions. Sorption was pH and concentration dependent. Simultaneous removal of BB3 and RO16 occurred at pH greater than 4. The kinetics of dye sorption fitted a pseudo-second order rate expression. Increase in agitation rate had no effect on the sorption of BB3 but increased uptake of RO16 on MRH. Decreasing particle size increased the uptake of dyes in binary dye solutions. Equilibrium data could be fitted into both the Langmuir and Freundlich isotherms. Maximum sorption capacities calculated from the Langmuir model are 14.68 and 60.24 mg/g for BB3 and RO16, respectively in binary dye solutions. This corresponds to an enhancement of 4.5 and 2.4 fold, respectively, compared to single dye solutions. MRH therefore has the potential of being used as an efficient sorbent for the removal of both dyes in textile wastewaters.

A novel mechanism for Bcr-Abl action: Bcr-Abl-mediated induction of the eIF4F translation initiation complex and mRNA translation.

The oncogenic kinase Bcr-Abl is thought to cause chronic myelogenous leukemia (CML) by altering the transcription of specific genes with growth- and survival-promoting functions. Recently, Bcr-Abl has also been shown to activate an important regulator of protein synthesis, the mammalian target of rapamycin (mTOR), which suggests that dysregulated translation may also contribute to CML pathogenesis. In this study, we found that both Bcr-Abl and the rapamycin-sensitive mTORC1 complex contribute to the phosphorylation (inactivation) of 4E-BP1, an inhibitor of the eIF4E translation initiation factor. Experiments with rapamycin and the Bcr-Abl inhibitor, imatinib mesylate, in Bcr-Abl-expressing cell lines and primary CML cells indicated that Bcr-Abl and mTORC1 induced formation of the translation initiation complex, eIF4F. This was characterized by reduced 4E-BP1 binding and increased eIF4G binding to eIF4E, two events that lead to the assembly of eIF4F. One target transcript is cyclin D3, which is regulated in Bcr-Abl-expressing cells by both Bcr-Abl and mTORC1 in a translational manner. In addition, the combination of imatinib and rapamycin was found to act synergistically against committed CML progenitors from chronic and blast phase patients. These experiments establish a novel mechanism of action for Bcr-Abl, and they provide insights into the modes of action of imatinib mesylate and rapamycin in treatment of CML. They also suggest that aberrant cap-dependent mRNA translation may be a therapeutic target in Bcr-Abl-driven malignancies.

Satisfaction of orthognathic surgical patients in a Malaysian population.

Thirty-one patients treated at the Faculty of Dentistry, University of Malaya, were assessed for their satisfaction following orthognathic surgery. The female to male ratio was 22:9 with an age range of 17 to 36. Almost all patients (97%) listed appearance as one of their rationales for surgery. More males (78%) than females (59%) wanted functional improvement, while more females (91%) than males (33%) hoped for improvement in self-confidence. All patients reported esthetic improvement while 68% each reported improvement in mastication and self-confidence. Slightly more than half (52%) chose esthetic improvement as the single most important factor resulting in satisfaction. Almost ninety percent of male patients claimed satisfaction with functional improvement, while 68% of those who found satisfaction in improved self-confidence were females. Eighty-seven percent rated their post-surgical changes as being well accepted by their family. The impact of these findings on the success of the surgery and the need to reinforce verbal communication with printed pamphlets are emphasized.

Orthognathic surgery in the University of Malaya.

This is the first review on orthognathic surgery in Malaysia. The records of a total of 84 patients seen between 1977 and 1999 in the Department of Oral and Maxillofacial Surgery of the Faculty of Dentistry, University of Malaya were analysed. Skeletal III deformity formed 85% of the sample with a female dominance of 2 to 1. The patients' age ranged from 17 to 36 years, with a mean of 25.3 years. The common surgical techniques used were combined bilateral sagittal split and Le Fort I osteotomy. The predominant ethnic group was Chinese (n = 58, 69%); followed by Malay (n = 14, 17%) and Indian (n = 12, 14%).

Aberrant FHIT mRNA transcripts are present in malignant and normal haematopoiesis, but absence of FHIT protein is restricted to leukaemia.

Aberrant FHIT mRNA transcripts are present in malignant and normal haematopoiesis, but absence of FHIT protein is restricted to leukaemia Alterations of the recently cloned fragile histidine triad (FHIT) gene at chromosome 3p14.2 are frequent in a variety of solid tumours and cancer cell lines. Based on these findings, FHIT has been proposed as a putative tumour-suppressor gene. We evaluated the mRNA expression of the FHIT gene in samples from 55 patients with various haematological malignancies (21 AML, 8 CML, 10 CLL, seven low-grade and nine high-grade Non-Hodgkin's lymphomas), in a panel of 16 leukaemia cell lines, in normal mature haematopoietic cells of both myeloid and lymphoid lineage, as well as in CD34+ haematopoietic progenitor cells. Aberrant FHIT mRNA transcripts were observed in 14/16 (88%) leukaemia cell lines, 43/55 (78%) primary haematological neoplasms, but also in 17/22 (77%) normal controls. 1/16 (6%) cell lines and 7/55 (13%) neoplasms did not express any FHIT mRNA. cDNA sequencing revealed exonic deletions, small DNA insertions and combinations of both. Analysis of genomic DNA showed gene deletions in two myeloid leukaemia cell lines. In contrast to all normal types of haematopoietic cells, FHIT protein was clearly reduced or absent in 8/18 (44%) neoplastic samples tested. Our data indicate that whilst aberrant FHIT mRNA transcripts are seen both in normal and malignant cells, lack of FHIT protein is restricted to leukaemia. Absent FHIT protein expression might contribute to leukaemogenesis.

Median mental sinus in twins.

Sinus on the chin can be the result of a chronic apical abscess due to pulp necrosis of a mandibular anterior tooth. The tooth is usually asymptomatic, and a dental cause is therefore not apparent to the patient or the unsuspecting clinician. Not infrequently, the patient may seek treatment from a dermatologist or general surgeon instead of a dentist. Excision and repair of the fistula may be carried out with subsequent breakdown because the dental pathology is not removed. This paper reports the presence of median mental sinus of dental origin in twins. One case healed following root canal therapy while the other required both root canal therapy and surgery to eliminate the infection.

Chromosomal abnormalities and molecular genetics of non-Hodgkin's lymphoma.

A number of recurring cytogenetic abnormalities have been identified in lymphomas that correlate with clinical, morphologic, and immunophenotypic features. For example, the t(14;18) is observed in a high proportion of follicular small cleaved cell lymphomas, most patients with translocations involving 3q27 have diffuse large cell lymphomas (B cell), and patients with a t(8;14) have either small noncleaved cell or diffuse large cell lymphomas. In contrast, a large proportion of neoplasms of T-cell origin are characterized by rearrangements that involve 14q11, 7q34-35, or 7p15. Molecular analysis of many of the recurring chromosomal translocations in lymphomas has resulted in the identification of the involved genes. Alterations in expression of these genes or in the production of an altered protein resulting from the rearrangement play an integral role in malignant transformation. In addition to chromosomal abnormalities, other types of mutations affecting oncogenes have been identified in lymphomas. This article reviews the genetic mutations involved in the pathogenesis of non-Hodgkin's lymphoma (NHL) with an emphasis on chromosomal abnormalities.

Lymphadenopathy, splenomegaly, and altered immunoglobulin production in BCL3 transgenic mice.

The candidate proto-oncogene BCL3 was isolated through its involvement in the t(14;19) found in chronic lymphocytic leukemia and other B-cell neoplasms. As a member of the I kappaB family, BCL3 plays a role in the immune response by interactions with the NF-kappaB family of transcription factors. In order to study the role of BCL3 overexpression in lymphoid malignancies, we generated five lines of E mu-BCL3 transgenic mice. Transgenic animals develop normally but show splenomegaly and an accumulation of mature B cells in lymph nodes, bone marrow and peritoneal cavity. A hyperresponsive immune system is suggested by the follicular hyperplasia and plasmacytosis in lymph nodes of unimmunized animals, increased incidence of antibodies to self-antigens, and a heightened response to cross-linking of surface IgM. Statistically significant decreases in serum IgM and IgG3, but an increase in IgG1 and IgA were also observed. No lymphoid neoplasms have been identified in transgenic animals. The expansion of B cells in vivo is consistent with the overexpression of BCL3 as being one step in the multi-step process of leukemogenesis. The phenotype also suggests that BCL3 plays a part in B cell proliferation and isotype switching.

Precise localization of the FHIT gene to the common fragile site at 3p14.2 (FRA3B) and characterization of homozygous deletions within FRA3B that affect FHIT transcription in tumor cell lines.

Chromosomal or allelic losses at 3p14 are common in a variety of human tumors, including those of the lung, breast, kidney, and head and neck. This suggests the existence of a tumor suppressor gene in this band. A promising candidate is the recently cloned FHIT gene, which spans the common fragile site, FRA3B, at 3p14.2. We previously identified a region of fragility at 3p14.2 (FRA3B) of > 85 kb by cloning DNA flanking pSV2neo integrations and constructed a partial genomic contig of the region. Using probes from the contig, we tested for deletions within this region in DNA from 105 human tumor cell lines, predominantly derived from lung cancers. We identified one gastric and four lung cancer cell lines with homozygous interstitial deletions involving the FRA3B region. The deletion in one lung cancer cell line lies entirely within our contig and is < 65 kb. We have identified, cloned, and sequenced this breakpoint junction. We have also shown that our probes lie within intron S of the FHIT gene and, furthermore, that exon 5 is located approximately 1 kb from one of our probes and, thus, lies within the region of fragility. Two lines with entirely intronic deletions yield FHIT transcripts of normal size. In one of these, this was the sole transcript identified. In the other line, an FHIT transcript completely normal in sequence was accompanied by two larger abnormal transcripts. These results leave open the possibility that some homozygous deletions within the FHIT gene are without phenotypic effect and result from genetic instability of this region. However, taken together, our results provide evidence that breakage and rearrangement within the FRA3B fragile site sequences result in alterations of FHIT and are likely to be involved in carcinogenesis.

FHIT and FRA3B 3p14.2 allele loss are common in lung cancer and preneoplastic bronchial lesions and are associated with cancer-related FHIT cDNA splicing aberrations.

We evaluated primary lung cancers, tumor cell lines, and preneoplastic bronchial lesions for molecular genetic abnormalities in the candidate tumor suppressor gene FHIT, which spans the FRA3B fragile site at 3p14.2. 3p14.2 allele loss was very frequent in 32 lung cancer cell lines [100% of small cell lung cancer and 88% of non-small cell lung cancer (NSCLC)] and 108 primary NSCLC cancers (45%), with numerous breakpoints indicating involvement of several distinct regions in the FRA3B site. 3p14 allele loss was least frequent in the adenocarcinoma subtype and occurred at the relatively late carcinoma in situ stage of preneoplastic bronchial lesions found in NSCLC patients. Homozygous deletions within the FHIT/FRA3B region were found in 6 of 135 (4.4%) thoracic cancer cell lines. Northern blot showed low or absent FHIT expression in most thoracic cancer cell lines tested, whereas reverse transcription-PCR showed that 59-62% exhibited aberrant FHIT transcripts but nearly always (93-100%) also expressing the wild-type transcripts. Aberrant transcripts included precise deletions of FHIT exons, insertion of non-FHIT sequences between exons and insertions replacing exons. Complete open reading frame single-strand conformational polymorphism analysis of 102 lung cancer cDNAs revealed only one nonsplicing mutation. Normal cells including bronchial epithelium, lung, and trachea expressed wild-type FHIT transcript and a variant transcript deleted for exon 8 but not the other aberrant transcripts, arguing against exon 8-deleted FHIT transcripts being tumor specific. Our findings support the conclusion that FHIT/FRA3B abnormalities are associated with lung cancer pathogenesis but that FHIT abnormalities differ from the types of mutations and lack of wild-type transcript found in classic tumor suppressor genes, and functional studies are needed to define the role of FHIT in thoracic tumorigenesis.

Florid cemento-osseous dysplasia in a young Chinese man. Case report.

Florid cemento-osseous dysplasia refers to a group of fibro-osseous lesions which are exuberant, multiquadrant and arise from the tooth-bearing area of the jaws. It is classically described as a condition occurring almost exclusively in middle-aged black women. A case of florid cemento-osseous dysplasia occurring in a young Chinese male is reported which was rare in regard to race and sex. This 20 year old Chinese man presented with huge symmetrical bony lesions in all four quadrants of the jaws. Clinical presentation, radiological findings and histological features of the excised specimens are described. Treatment of the lesions was unusual. Curettage was first done with minimal benefit and it was followed by mandibular recontouring to improve facial appearance. The outcome of these procedures will be discussed.

Adenomatoid odontogenic tumour: a case study with radiographic differential diagnostic considerations.

Adenomatoid odontogenic tumours (AOT) are benign, hamartomatous odontogenic lesions that not uncommonly mimic a dentigerous cyst radiographically. Such a case as found involving an unerupted left maxillary canine in a 19-year-old Chinese female is described. The differential diagnosis of some common odontogenic cysts and neoplasms occurring in Malaysians, that may present in a dentigerous relationship to an unerupted tooth is discussed. A brief review of the radiographic literature on AOT is also included.

Direct cloning of DNA sequences from the common fragile site region at chromosome band 3p14.2.

Despite several lines of evidence suggesting that common chromosomal fragile sites are biologically important as hot spots for recombination, their structure remains unknown. We showed previously that the plasmid pSV2neo preferentially integrates into bands containing fragile sites in cells transfected under conditions of fragile site induction. Here we report the isolation and characterization of the DNA sequences from two such independent integrations into 3p14.2, a common fragile site (FRA3B). These FRA3B region sequences were shown to lie within a 1330-kb YAC, 850A6, approximately 350 kb telomeric of the breakpoint of t(3;8), a constitutional rearrangement. The two integration sites are 10 kb apart, but each integration is associated with a deletion. We have constructed a partial genomic contig of the integration sites and deleted regions spanning approximately 85 kb. Analysis of the DNA sequences immediately surrounding the plasmid integrations revealed no known coding sequences or repeat structures resembling the (CGG)n motif characteristic of the rare fragile sites. In addition, by Southern blotting analysis, none of the phage clones isolated from the FRA3B region were found to contain CGG repeats. Fluorescence in situ hybridization analysis of genomic clones from this contig to metaphase cells induced to express breaks demonstrated hybridization adjoining the chromosome breaks, and occasionally the hybridization signal spanned the break. The results imply that breakage occurs at variable positions within a large region (at least on the order of 85 kb). Together, these data suggest that the structure of FRA3B differs from that of rare fragile sites.

Chemotherapy in malignant pleural mesothelioma. A review.

PURPOSE AND DESIGN: We reviewed the published literature of clinical studies in malignant pleural mesothelioma, including phase II trials of the newer antifolates and plant derivatives, as well as older single-agent and combination chemotherapy trials. We excluded trials with less than 15 patients, although we have mentioned smaller trials in the text to make a specific point, as well as ones that show promise. We have also included confidence intervals when cited in the original reports, or calculated them when absent. RESULTS: No drugs have consistently induced a response greater than 20%. Higher response rates have been reported with detorubicin, high-dose methotrexate, and edatrexate at 26%, 37%, and 25%, respectively, but these have yet to be confirmed. Agents that produce response rates in 10% to 20% of patients include doxorubicin, epirubicin, mitomycin, cyclophosphamide, ifosfamide, cisplatin, and carboplatin. Combination chemotherapy trials do not demonstrate a consistently greater response rate than single-agent trials. However, the combination of doxorubicin, cisplatin, bleomycin, and mitomycin demonstrated a response rate of 44% (95% confidence interval, 27% to 63%), but this remains unconfirmed. Intrapleural therapy using interferon gamma, particularly for small-volume disease, shows promise. CONCLUSION: The successful treatment of unresectable pleural mesothelioma awaits the discovery of active drugs. Recent trials of high-dose methotrexate and other antifolates are encouraging. Newer agents, including suramin, should be evaluated in phase II trials. Off-protocol combination therapy cannot be recommended over single-agent therapy, but studies that use combinations of the newer agents should be conducted.

Current management of acute lymphoblastic leukemia in adults.

Intensive remission chemotherapy followed by post-remission consolidation and maintenance therapies has achieved complete remission rates of 75% to 90% and 3-year survival rates of 25% to 50% in adults with acute lymphoblastic leukemia (ALL). These results, although promising, are still less favorable than those achieved in childhood ALL. However, various novel experimental and clinical approaches show promise for improving cure rates. Also, specific therapies directed at high-risk subgroups with ALL are beginning to emerge. Detection of specific chromosomal abnormalities at diagnosis identifies patients who are at risk of failing to achieve remission, as well as those who are likely to have short, intermediate, or prolonged disease-free intervals after successful remission induction. Such prognostic information may, ultimately, be used to assign risk categories and to individualize post-remission therapy.

Hepatic candidiasis: persistent pyrexia in a patient with acute myeloid leukaemia after recovery from consolidation therapy-induced neutropenia.

Fever, a frequent manifestation in acute leukaemia patients who develop treatment-induced neutropenia, usually resolves when the neutrophil count returns to normal irrespective of whether an infective agent is isolated or not. A persistent pyrexia following neutrophil recovery and associated with multiple negative microbiological cultures should signal a careful search for a deep-seated fungal infection in any leukaemic patient who is complete remission. We report here a 39-year-old Chinese man with acute myeloid leukaemia in first complete remission whose unresolved fever after recovery from consolidation therapy-induced neutropenia was ultimately confirmed to be caused by focal hepatic candidal microabscesses by an open liver biopsy.

Chronic disseminated histiocytosis X: a case report.

A case of chronic disseminated histiocytosis X (Hand-Schuller-Christian Disease) of the mandible is presented. Multi-modal approach to management is discussed.