PubMed Health⌕ Search

Biomedical subjects

D Wickramasinghe

Publications and source records attributed to D Wickramasinghe.

11 recordsLinked to original sources
PubMed2005

Lymphoedema and its management in cases of lymphatic filariasis: the current situation in three suburbs of Matara, Sri Lanka, before the introduction of a morbidity-control programme.

Using in-depth interviews, information on the current state of lymphoedema management was collected from 101 cases of lymphatic filariasis with lymphoedema in three suburbs of Matara. The interviews were conducted prior to the introduction of a programme of community home-based care (CHBC) that incorporates modern lymphoedema-management strategies. Thirty-two of the interviewees had severe lymphoedema (of grade III or above). The male interviewees had significantly more entry lesions than the female. Most of the subjects had suffered from episodes of limb pain with fever, although the incidence of these episodes appeared unrelated to the severity of the lymphoedema. The frequency of the episodes of limb-pain/fever in the 12 months prior to the interviews appeared unrelated either to the level of daily hygiene, which was generally poor, or to the frequency of bathing. Many (65%) of the subjects paid no attention to limb care when bathing, and 44% did not use footwear. Over 80% made no effort to keep their afflicted limbs elevated, and 95% did not exercise. Most of the female interviewees felt shameful of their condition and were, in consequence, less likely to attend government clinics, for treatment, than the male interviewees. The drug treatment that the interviewees had received was often inadequate, and most had stopped seeking treatment because they had not perceived any significant treatment-attributable improvement in their condition. Modern lymphoedema-management strategies (based on regular washing, careful drying, and treatment, with antifungal, antibiotic or emollient creams, of the affected limbs, limb elevation, exercise, and use of footwear) had not reached the study communities and the local physicians were not aware of them. When dermatology life-quality indexes (DLQI) were calculated for the interviewees, the 26 most impaired subjects gave scores of 5-15 (mean=8.6). The DLQI for these subjects will be regularly re-evaluated, as a measure of the effectiveness of the CHBC programme that has now begun.

Adolescent↗
PubMed2003

Knowledge on lymphatic filariasis and the response to July 2002 mass treatment campaign in two communities in the Galle district.

OBJECTIVE: To ascertain the knowledge on filariasis and response to the July 2002 mass treatment campaign in two sample populations. DESIGN: Application of pre-tested questionnaire by direct interviews of individuals from randomly selected streets. METHODS: Study areas were a coastal community in Unawatuna (population sample 381), and an inland community in Baddegama (population sample 236) in the Galle district. They were interviewed twice, 4 weeks before the mass drug administration (MDA) and 4 to 7 days after. RESULTS: The sample population of Unawatuna had a greater awareness of the clinical and parasitological features of the disease (p = 0.0003) and the drug treatment (p = 0.00380 than that of Baddegama. Only 5.5% of the combined sample attributed the cause of filariasis to a parasitic worm. However, over 70.0% of them knew that transmission was through mosquito bites. Volunteers formed 87.5% of the work force used for drug distribution in Unawatuna and 70.1% in Baddegama. The balance work force were Grama Niladaris and Public Health Midwives. Drugs were received by 76.9% of the Unawatuna sample compared with 89.0% at Baddegama (p < 0.001). Among those who received the drugs, consumption was 91.8% in Unawatuna and 96.2% in Baddegama. Taking the two communities together adverse effects were experienced by 22.9%. These effects in night time drug consumers (10.4%) were significantly less than in day time consumers (19.8%) (p < 0.005). The adverse effects were sleepiness (37.8%), malaise (28.2%), headache (16.8%), vomiting (5.1%), nausea (4.5%) and fever (3.9%). The message of mass treatment was carried to the community by the people themselves on the eve and on the day of drug distribution. Over 95% agreed that in future programs drugs should be delivered to their homes.

Animals↗
PubMed2003

Prenatal testing and pregnancy termination in Sri Lanka: views of medical students and doctors.

INTRODUCTION: Prenatal diagnosis and pregnancy termination generate complex ethical issues. Surveys conducted in Sri Lanka among doctors and medical students in 1986 supported a change in law in favour of pregnancy termination when gross genetic defects are detected antenatally. A new generation of prenatal tests has focused attention again on the topic of termination and under what circumstances it might be legally done. The present survey contributes to the debate by means of a survey of doctors and medical students. METHOD: A self-administered questionnaire given to doctors and medical students. RESULTS: Ninety three per cent of doctors and 81% of students accept pregnancy termination as an appropriate course of action if a gross genetic defect is detected antenatally, and 87% of doctors and 80% of students support a change in the law to allow termination of the pregnancy. The corresponding figures in previous surveys were 80%, 69% and 96%, 88% respectively. CONCLUSIONS: A majority of doctors and medical students support a change in law in favour of liberalising pregnancy termination when a genetic defect is detected antenatally.

Abortion, Induced↗
PubMed2000

Structure and promoter activity of the mouse CDC25A gene.

CDC25A is a member of a group of highly related, dual-specificity phosphatases that promote cell cycle phase transitions by regulating the activity of cyclin-dependent kinases. Here we report the cloning and genomic sequence of 21,067 nucleotides encompassing the mouse CDC25A gene. The coding sequence is expressed from 17,904 bp of genomic DNA comprising 15 exons. We also mapped the transcription initiation site to a consensus initiator element proximal to an SP1 site. Approximately 1 kb of sequence upstream of the transcription initiation site confers promoter activity and cell type specificity to a reporter gene construct. Surprisingly, transcription from this promoter was repressed by over-expression of catalytically active but not catalytically inactive CDC25A protein. We also show, using NIH 3T3 cells, that murine CDC25A mRNA levels fluctuate only modestly over the cell cycle. Our findings provide insights into the regulation of CDC25A expression and have facilitated construction of gene knock-out vectors.

3T3 Cells↗
PubMed1998

The four cdc25 genes from the nematode Caenorhabditis elegans.

During eukaryotic evolution, multicellular organisms have evolved multiple members of gene families that may display unique, partially overlapping, or redundant functions during development. More than 75% of the C. elegans genome has been sequenced, which represents approximately 95% of the coding sequences. This provides a unique opportunity to identify most, if not all, of the members of a given gene family. We have searched the C. elegans genome database for members of a key family of cell cycle regulators, the CDC25 phosphatases, and have identified four genes. The four C. elegans genes represent a larger family within a single organism than has been reported so far in Drosophila, mice and humans. An amino acid comparison revealed a high degree of similarity and identity within the phosphatase domain. This analysis also identified an expanded consensus sequence that can be used to discover new members of the CDC25 phosphatase family. However, the four C. elegans sequences display a few novel amino acid substitutions in the residues surrounding the invariant catalytic motif CX5R. These data demonstrate the value of genome database searching for identifying new members of known gene families, understanding genetic diversity, and for studying gene structure.

Amino Acid Sequence↗
PubMed1995

Two CDC25 homologues are differentially expressed during mouse development.

The cdc25 gene product is a tyrosine phosphatase that acts as an initiator of M-phase in eukaryotic cell cycles by activating p34cdc2. Here we describe the cloning and characterization of the developmental expression pattern of two mouse cdc25 homologs. Sequence comparison of the mouse genes with human CDC25 genes reveal that they are most likely the mouse homologs of human CDC25A and CDC25B respectively. Mouse cdc25a, which has not been described previously, shares 84% sequence identity with human CDC25A and has a highly conserved phosphatase domain characteristic of all cdc25 genes. A glutathione-S-transferase-cdc25a fusion protein can hydrolyze para-nitro-phenylphosphate confirming that cdc25a is a phosphatase. In adult mice, cdc25a transcripts are expressed at high levels in the testis and at lower levels in the ovary, particularly in germ cells; a pattern similar to that of twn, a Drosophila homolog of cdc25. Lower levels of transcript are also observed in kidney, liver, heart and muscle, a transcription pattern that partially overlaps, but is distinct from that of cdc25b. Similarly, in the postimplantation embryo cdc25a transcripts are expressed in a pattern that differs from that of cdc25b. cdc25a expression is observed in most developing embryonic organs while cdc25b expression is more restricted. An extended analysis of cdc25a and cdc25b expression in preimplantation embryos has also been carried out. These studies reveal that cdc25b transcripts are expressed in the one-cell embryo, decline at the two-cell stage and are re-expressed at the four-cell stage, following the switch from maternal to zygotic transcription which mirrors the expression of string, another Drosophila homolog of cdc25. In comparison, cdc25a is not expressed in the preimplantation embryo until the late blastocyst stage of development, correlating with the establishment of a more typical G1 phase in the embryonic cell cycles. Both cdc25a and cdc25b transcripts are expressed at high levels in the inner cell mass and the trophectoderm, which proliferate rapidly prior to implantation. These data suggest the cdc25 genes may have distinct roles in regulating the pattern of cell division during mouse embryogensis and gametogenesis.

Amino Acid Sequence↗
PubMed1994

Cycling with CDKs.

Explore the source record for details and available documents.

Journal Article↗
PubMed1992

Centrosome phosphorylation and the developmental expression of meiotic competence in mouse oocytes.

Previous studies suggested that the transition from an incompetent to a competent meiotic state during the course of oogenesis in the mouse involved a G2/M-like cell cycle transition (Wickramasinghe et al, 1991. Dev. Biol. 143, 162). The present studies tested the hypothesis that centrosome phosphorylation, an event normally induced by MPF, is required for this developmental transition and the expression of meiotic competence in cultured growing mouse oocytes. Multiple fluorescence labeling techniques were used to evaluate centrosome number, phosphorylation status, and microtubule nucleating capacity in competent and incompetent oocytes. Experimental conditions were established for reversibly altering the phosphorylation status of the centrosomes and the effects of these treatments on meiotic resumption were examined. Phosphorylated centrosomes nucleating short microtubules were observed in competent oocytes, whereas nonphosphorylated centrosomes and interphase microtubule arrays were found in incompetent oocytes. Upon recovery from nocodazole-induced microtubule depolymerization, short microtubules formed from centrosomes in competent oocytes, whereas long microtubules reappear in the cytoplasm of incompetent oocytes. Perturbation of the phosphorylation state of oocytes with activators of protein kinase A or protein kinase C resulted in the formation of long interphase microtubules in competent oocytes while centrosome phosphorylation was maintained. Treatment of competent oocytes with the phosphorylation inhibitor 6-dimethylaminopurine also led to formation of long microtubules, although under these conditions centrosomes were dephosphorylated. When competent oocytes were treated simultaneously with puromycin and the phosphodiesterase inhibitor isobutyl methylxanthine (IBMX) for 6 hr, centrosomes became dephosphorylated; centrosomes were rephosphorylated when competent oocytes were further cultured in IBMX without puromycin. Conditions that induced centrosome dephosphorylation in competent oocytes resulted in the loss of the ability to express meiotic competence in culture, whereas maintenance of centrosome phosphorylation in these oocytes was correlated with the ability to resume meiosis. These results suggest that the G2/M transition that occurs when mouse oocytes progress from an incompetent to a competent state in vivo involves the phosphorylation of centrosomes and that the maintenance of centrosome phosphorylation is required for the in vitro expression of meiotic competence.

1-Methyl-3-isobutylxanthine↗
PubMed1991

Meiotic competence acquisition is associated with the appearance of M-phase characteristics in growing mouse oocytes.

To determine whether the acquisition of meiotic competence during the growth phase of oogenesis is associated with the appearance of M-phase characteristics, oocytes obtained from 13- to 30-day-old mice were evaluated by fluorescence microscopy with respect to chromatin and microtubule organization , in vitro maturation ability, and the distribution of M-phase phosphoproteins. Meiotically incompetent oocytes were distinguished from their competent counterparts in displaying elaborate interphase-like arrays of cytoplasmic microtubules and dispersed germinal vesicle chromatin. Meiotically competent oocytes were larger in size, exhibited condensation of chromatin around the nucleolus, and displayed a progressive diminution of cytoplasmic microtubules in conjunction with the appearance of multiple microtubule organizing centers. After 24 hr in culture, medium- to large-sized oocytes exhibiting perinucleolar chromatin condensation resume meiosis whereas smaller meiotically incompetent oocytes retain GVs with diffuse chromatin. Moreover, indirect immunofluorescence studies using the M-phase phosphoprotein specific monoclonal antibody MPM-2 indicate that the appearance of reactive cytoplasmic foci is directly correlated with nuclear changes characteristic of meiotically competent oocytes. Thus, the earliest transition to a meiotically competent state during oocyte growth in the immature mouse ovary is characterized by stage-specific and coordinated modifications of nuclear and cytoplasmic components.

Animals↗