Nanocomposites of Zn/Al-layered double hydroxide(anthraquinone-2,6-disulfonate) were synthesized by spontaneous direct assembly of inorganic and organic phases from aqueous solution. Powder X-ray diffraction patterns showed that a pure, single nanocomposite phase of good crystallinity was obtained using 1.0 M antraquinone-2,6-disulfonate ion (AQ26) and aging at 80 degrees C using conventional heating for 7 days or 0.5 h under microwave radiation, and these samples are denoted as ZAAN26C or ZAAN26MH, respectively. Zn/Al-nitrate-layered double hydroxide synthesized by a conventional method (ZANLC) showed a basal spacing of 8.3 A while both the nanocomposites showed 18.8 A as a result of AQ26 intercalation. FTIR study showed that the resulting nanocomposites are free from nitrate, the co-anion present in the mother liquor, indicating that only AQ26 is preferred during intercalation for the formation of the nanocomposite. The Brunauer, Emmet and Teller (BET) and micropore surface areas for ZAAN26C decreased relative to the ZANLC from 16.2 to 4.7 and 1.6 to 1.3 m2/g, respectively. These results indicate that AQ26 can be rapidly interdcalated in layered double hydroxide using microwave-aging resulting in a nanocomposite.
Sickle cell disease is an inherited disorder and individuals who are homozygous for the sickle cell gene (HbS/S) show the clinical manifestations of the disease. The individuals who are heterozygous for the sickle cell gene (HbA/S) are referred to as sickle cell trait. In these people, under normal circumstances, symptoms are usually absent or mild. However, thorough investigation of the latter condition is also important, because sickling could occur under certain situations, such as prolonged hypoxia. The level of haemoglobin S(HbS), the ratio of HbS to haemoglobin A (HbA) and the presence of variants such as haemoglobin C (HbC) can alter the entire course of the condition. An unexpected sudden death in a 41-year-old Nigerian, who was apparently in good health and was on a long duration flight, is presented. According to available evidence he was previously diagnosed to be suffering from sickle cell trait. Based on medical advice oxygen was supplied to him throughout the flight. Two hours prior to landing at the international airport in Kuala Lumpur, Malaysia he suddenly became breathless and died shortly after. Autopsy revealed that the immediate cause of death was pulmonary thrombo-embolism originating from calf vein thrombosis. It was also established that the thrombus in the calf vein was not pre-existing. Histology revealed that there was extensive and generalized sickling. Haemoglobin electrophoresis on the postmortem sample of blood confirmed that the deceased had Hb S/C disease and not sickle cell trait. The presence of HbC together with the long hours of flight and associated inactivity had probably complicated the case. Various aspects of the sickle-cell condition are highlighted. Allegations of negligence were made against the airline and the doctor who cleared the deceased in Nigeria (the deceased was employed in a well-known multinational company) for long distance non-stop air travel. Various medico-legal issues pertaining to the cause and mode of death, the importance of an accurate diagnosis of the precise sickling disorder and possible negligence on the part of various agencies are discussed.
Rape is one of the fastest growing violent crimes in many parts of the world. Rape laws have been amended in most countries in an attempt to cope with the proliferation of this crime. Even though the legal definition of rape and the procedural laws have been amended, rape remains a serious problem in both the developed and developing nations. In some countries the offence of rape carries severe punishment sometimes even the death sentence. In many jurisdictions the term 'sexual penetration' is being used instead of 'sexual intercourse'. Sexual penetration includes sexual intercourse, anal intercourse, cunnilingus, fellatio or any other intrusions involving any part of a human body or of any object into the genital or anal opening of a person's body. In many countries rape and other sexual offences have been replaced with a series of gender neutral and graded offences with appropriate punishments. Medical examination can provide independent, scientific, corroborative evidence that may be of value to the court in arriving at a judgement. Doctors should have a clear understanding of different rape laws in order to apprectiate the various issues involved. Special knowledge, skill and experience are essential to conduct a good-quality medical examination. There is a dearth of trained forensic physicians in many Asian countries. However, managing a rape victim (survivor) goes for beyond proving the case in a court of law. There should be an adequate rehabilitation programme available to the victims to help them cope.
Medico-legal problems experienced by histopathologists differ from those of other clinicians as they are rarely in direct contact with patients. Nevertheless, the pathologist owes a duty of care to the patient and is liable for medical negligence. In the absence of local guidelines, it is prudent to follow guidelines published by learned Colleges elsewhere. This is also true when delegating duties to non-pathologists, technical and other support staff. Errors in diagnosis and documentation pose the most common problems in histopathology. In this, liability also depends on many factors including the provision of adequate clinical information by clinicians and competence of laboratory staff. Clinicopathological discussions, participation in quality assurance programmes and adherence to standard operating procedures are important audit activities to minimize and detect errors as well as prevent grievous outcome to patients. Issues also arise over the retention of specimens and reports. In general, wet, formalin-fixed tissues should be kept until histopathological assessment is finalized and preferably after clinicopathological sessions, and even longer if there is potential litigation. Reports should be archival. Paraffin blocks should be kept for at least the lifetime of the patient, and histology slides for at least 10 years, to facilitate review and reassessment. Despite adverse publicity in the foreign press over the use of human organs and tissues for research and education, it is accepted that processed tissues can be used for research and educational purposes provided the patient's identity is kept confidential. Nevertheless, it would be prudent to revise consent forms for surgery and autopsies to include the possibility that tissues removed can be stored or used for research and education. Good medical practice in pathology encourages a willingness to consult colleagues when in doubt, but advises that the treating clinician be informed if histopathological material is referred away for a second opinion. The Telemedicine Act of Malaysia (1997) requires practitioners outside Malaysia providing diagnosis through telepathology to hold a certificate to practice telemedicine issued by the Malaysian Medical Council. It is likely that the medico-legal scene in histopathology will change in the coming years with the advent of other new ancillary investigative techniques.
p53 is the most commonly mutated gene in human cancers. It encodes a 53 kilodalton protein with several evolutionarily conserved domains viz sequence-specific DNA binding, tetramerisation, SH3 molecule binding, C-terminal and N-terminal. Existing in the cell at a very low level and in a relatively inactive form, p53 protein is increased and activated during periods of cellular stress. Unlike other proteins, the increase in protein level and its activation result from modification of the protein rather than genetic transcriptional or translational upregulation. Normally, Mdm2 protein interacts with p53 protein and effectively targets it for ubiquitin proteolysis within an autoregulatory feedback loop. Phosphorylation at the N-terminus reduces p53 interaction with Mdm2 with a resultant increase in p53 protein level. Modification at the C and N termini via phosphorylation or acetylation upregulates binding to specific DNA targets increasing transcription of these downstream genes. The net effect of p53 protein increase and activation lies in arrest of the cell in cycle which allows time for repair of the incurred damage or apoptosis or death of the cell. Failure of these normal protective and adaptive mechanisms caused by mutation of the p53 gene with product of an abnormal protein, loss of p53 protein through interaction with and degradation by HPV E6 protein or overexpressed Mdm2 etc. permits DNA-damaged cells to continue replicating. Left unchecked, this frequently contributes to tumourigenesis. Various methods have been devised to screen for mutations of the p53 gene, still the most common source of failed p53 mechanism. These include immunohistochemical detection of mutated proteins or identification of altered electrophoretic mobility of mutated p53 sequences. Sequencing of the gene nonetheless remains the most accurate method for determination of mutation. Major advances have been made in p53 research but the most meaningful probably lies in the promising results achieved in tumour therapy where introduction of wild type p53 gene has resulted in regression of non-small-cell lung cancer (NSCLC). Many other notable developments in this field include description of p53 homologues, "gain of function" mutants, p53 polymorphisms, angiogenesis-inhibiting properties of wild type p53 protein etc.
MeSH terms: DNA, Neoplasm/genetics; Humans; Mutation*; Neoplasms/genetics*; Neoplasms/metabolism; Neoplasms/pathology; Genes, p53*; Tumor Suppressor Protein p53/genetics*; Tumor Suppressor Protein p53/metabolism; Biomedical Research
This study investigated the effects of a tocotrienol-rich fraction (TTRF) on the microscopic development of atherosclerosis and lipid peroxidation in the aorta of rabbits. Group 1 was fed a normal diet, group 2 received a 2% cholesterol diet and group 3 received a 2% cholesterol diet plus daily oral administration of the TTRF. After 10 weeks, the aortic content of malondialdehyde (MDA) was measured as an index of lipid peroxidation. The MDA was lowest in rabbits that received the TTRF compared to the groups that did not. The degree of intimal thickening was higher in the cholesterol-fed rabbits without the TTRF compared to the cholesterol-fed rabbits with TTRF (P<0.05). The continuity of the internal elastic lamina (IEL) was noted to be preserved in the cholesterol-fed rabbits with TTRF but appeared disrupted in the cholesterol-fed rabbits without the TTRF. The disrupted and fragmented IEL may have resulted from the injury caused by lipid peroxidation that contributed to the more extensive intimal thickening. We conclude that the antioxidant activities of the TTRF can reduce experimental atherosclerosis.
Ki-67 expression in diffuse proliferative lupus nephritis, WHO Class IV, was compared against normal controls to establish that cellular proliferation is involved in the production of glomerular hypercellularity. Twenty-three histologically confirmed WHO Class IV lupus nephritis and 23 normal control renal tissue were immunohistochemically stained with a polyclonal antibody to Ki-67 (Dako) using the peroxidase labelled streptavidin bioitin kit (Dako). There were 20 females and 3 males, with 17 Chinese and 6 Malays in the WHO Class IV lupus nephritis group. Ages of patients ranged between 10-56 years with a mean of 31.9 years. The normal controls, 20 males and 3 females, and ethnically 9 Indians, 7 Malays, 2 Chinese, and 5 foreign nationals (4 Indonesians and 1 Bangladeshi), had an age range between 15-33 years (mean = 23.3 years). Sixteen (69.6%) WHO Class IV lupus nephritis and 8 (34.8%) normal controls demonstrated Ki-67 immunoreactivity in at least 1 glomerulus (p<0.05). Of the 256 WHO Class IV lupus nephritis non-sclerosed, glomeruli studied, 37 (14.5%) were Ki-67 immunopositive compared with normal controls where 16 (0.7%) of 2159 glomeruli demonstrated Ki-67 (p< 0.01). Cellular proliferative activity, as evidenced by Ki-67 expression, was significantly increased in WHO Class IV lupus nephritis confirming that cell proliferation contributes to glomerular hypercellularity.
This paper evaluates the practice of fresh frozen plasma (FFP) transfusion at the University Hospital, Kuala Lumpur, and analyses its usage by the various clinical departments. The aim of this study is to identify where it is inappropriately used and the clinical indications in which such misuse is common. A retrospective analysis of the blood bank request forms and work sheets during a 6-month period between January 1998 and June 1998 formed the basis of this study. Overall, 40% of 2665 units transfused were considered appropriate. However, out of the 931 episodes of FFP transfusions only 31% were for appropriate indications. The average FFP requirement when used for appropriate indication was about 4 units per episode, whereas for inappropriate indication it was 2.5 units per episode. Inappropriate use in terms of the number of units was highest by the surgical services (68%) and Orthopaedics (64%), while the Department of Paediatrics had the lowest incidence of inappropriate use (40%). When Paediatrics was used as the benchmark, the incidence of inappropriate use by other departments was significantly higher (p < 0.01). As for FFP usage in common clinical indications, there was a high incidence of inappropriate use in burns (82%), perioperative period (73%), cardiac surgery (68%), massive bleeding (62%) and trauma (60%). The findings in this study, specifically the use of FFP for volume support in trauma, massive bleeding and burns, routine requests without identified indication in cardiac bypass surgery, and prophylactic use in the perioperative period can be the basis for recommendations to minimize the inappropriate use of FFP in the future.
MeSH terms: Commission on Professional and Hospital Activities*; Developing Countries*; Hospitals, University*; Humans; Malaysia; Plasma*; Utilization Review*; Blood Component Transfusion/standards; Blood Component Transfusion/utilization*
The aim of this study was to determine the incidence and outcome of herpes zoster hospitalised children with cancer in Kota Baru. It was a retrospective review from January 1994 to December 1998. The diagnosis of herpes zoster was a clinical one. Herpes zoster was diagnosed in 10 of 188 (5%) children with malignancy. The most common malignancy was leukaemia. Nine children were treated with acyclovir. No child developed visceral dissemination and there were no deaths.
Age-adjusted death rates for coronary heart disease (CHD) have been decreasing in populations of developed countries. At the same time, CHD in the Asia-Pacific region appears to be increasing in parallel with the 'Westernisation' of diet and lifestyle. More epidemiological information is needed from the Asia-Pacific region in order to be able to predict trends in CHD and to plan resources for treatment. In this paper we outline the study design of a survey of coronary heart disease risk factors in Asia-Pacific countries.
MeSH terms: Environment; Government Agencies/economics; Government Agencies/history; Government Agencies/legislation & jurisprudence; Great Britain/ethnology; Malaysia/ethnology; Local Government; Pest Control, Biological/economics; Pest Control, Biological/history; Pest Control, Biological/legislation & jurisprudence; Pesticides/history; Public Health/economics; Public Health/history; Rural Population/history; Colonialism/history; History, 20th Century
This paper introduces a new set of orthogonal moment functions based on the discrete Tchebichef polynomials. The Tchebichef moments can be effectively used as pattern features in the analysis of two-dimensional images. The implementation of the moments proposed in this paper does not involve any numerical approximation, since the basis set is orthogonal in the discrete domain of the image coordinate space. This property makes Tchebichef moments superior to the conventional orthogonal moments such as Legendre moments and Zernike moments, in terms of preserving the analytical properties needed to ensure information redundancy in a moment set. The paper also details the various computational aspects of Tchebichef moments and demonstrates their feature representation capability using the method of image reconstruction.
Bacterial screening employing the agar diffusion test on triphenyltin carboxylates containing various functional residues in the ester moiety revealed appreciable differences in their activities relative to triphenyltin acetate. Among these, [3-(Diethylphosphono)propionato] triphenyltin (1) and [N-cyclohexylcarbamoyl) glycinato] triphenyltin displayed activities comparable to tri-n-butyltin cinnamate (2) towards both Gram-positive and Gram-negative bacteria; the latter compound was the most active among the eleven triorganotin compounds tested, which included cyclopentyldiphenyltin hydroxide (3) and its methacrylate derivative. Applying the more quantitative plate count and optical density tests on compounds 1-3, it was shown that their inhibitory activity ranked in the order 2 > 3 >1. Significantly, 3 caused around 90% inhibition of both Eschechia coli (-) and Pseudomonas aeruginosa (-) when incubated for 24 h at 37+/-1 at the 10.0 mug/ mL concentration level. Compound 2 was less effective against P.aeruginosa than against E.coli. While the Gram-positive bacteria were all readily inhibited, Bacillus subtilis (+) appeared to the most susceptible among them towards the test compounds.