Decrease in laser ablation threshold for epithelial tissue microsurgery in a living Drosophila embryo during dorsal closure

In this work, we use a two-photon fluorescence microscope for combined imaging and laser tissue ablation of a living Drosophila Melanogaster embryo. By using tightly focused near-infrared femtosecond pulses at MHz repetition rate and of sub-nanojoule energy we are able to produce microsurgery on the epithelial tissue within a Drosophila embryo at the final stages of its embryonic development. Ablation was performed on labelled and unlabelled embryos during and after dorsal closure. We observed that ablation of GFP-labelled tissue required lower energy deposition than unlabelled tissue ensuring that the tissue ablation is mediated by multiphoton absorption of Green Fluorescent Protein (GFP). In addition, the energy deposition to produce ablation is further decreased during dorsal closure. These results show the presence of additional tensile forces on the tissue during dorsal closure. Furthermore, an increased activity of actin near the laser wounds was observed as the tissue heals.

High-power, continuous-wave, second-harmonic generation at 532 nm in periodically poled KTiOPO(4)

We report efficient generation of high-power, cw, single-frequency radiation in the green in a simple, compact configuration based on single-pass, second-harmonic generation of a cw ytterbium fiber laser at 1064 nm in periodically poled KTiOPO(4). Using a crystal containing a 17 mm single grating with period of 9.01 microm, we generate 6.2 W of cw radiation at 532 nm for a fundamental power of 29.75 W at a single-pass conversion efficiency of 20.8%. Over the entire range of pump powers, the generated green output is single frequency with a linewidth of 8.5 MHz and has a TEM(00) spatial profile with M(2)<1.34. The demonstrated green power can be further improved by proper thermal management of crystal heating effects at higher pump powers and also by optimized design of the grating period to include thermal issues.

Survivors of tobacco-related diseases and advocacy for tobacco control

Survivors and victims of tobacco-related diseases can and should play significant roles in tobacco control advocacy efforts. This article describes one example of how to successfully incorporate their talents into a statewide programme.

Voice disorders in HIV-infected individuals: a preliminary study

HIV-1 infects brain cells, and this results in damage to the functioning of both the central and peripheral nervous systems. Progressive decline in communication behaviours can be seen from early stages of infection. Among the communication problems observed in those infected with HIV are speech, language, cognition and swallowing. This study was undertaken with the aim of creating a profile of the vocal impairments in individuals affected with HIV/AIDS, which would in turn support evidence-based practices in the assessment and management of such individuals. Eight participants were included in the study. Subjective analysis was carried out by a speech pathologist and objective analysis of acoustic parameters, by the use of Kay Elemetrics MDVP software. The results of the study reveal that all participants had affected parameters in the voice analysis, which ranged across subjects from one parameter to all parameters. Even in the absence of direct pathology to the voice production mechanism, almost all of the parameters of voice are affected in HIV-infected persons. As this is a preliminary study, it is too early to conclude that there is a correlation between vocal deviancies and medical conditions.

Cotyledonoid leiomyoma in pregnancy

BACKGROUND

Benign smooth-muscle tumors (leiomyomata) are the most frequent tumors found in the female genital tract. They are easy to diagnose in pregnancy and usually managed conservatively. Some variant forms with unusual infiltrative growth pattern have been known, but they are rare in pregnancy. The variant forms pose diagnostic and management difficulties.

CASE

An unusual type of leiomyoma (cotyledonoid), adhering to the bowels and occupying the whole left broad ligament, was excised completely at 14 weeks of gestation, and the pregnancy continued to term.

CONCLUSION

Familiarity with benign uterine smooth-muscle tumors with unusual growth patterns by gynecologists and pathologists is essential in avoiding over-treatment.

Antimicrobial activity of Curcuma zedoaria and Curcuma malabarica tubers

The antimicrobial activity of extracts of Curcuma zedoaria and Curcuma malabarica tubers was tested against six bacterial and two fungal strains using the agar well diffusion and broth dilution methods. Petroleum ether, hexane, chloroform, acetone and ethanol extracts exhibited antibacterial as well as antifungal activity. Acetone and hexane extracts of both tubers showed comparable antimicrobial activity as indicated by minimum inhibitory concentration (MIC) values, but other extracts of Curcuma malabarica showed significantly lower activity than those of Curcuma zedoaria. The MIC values for different strains and extracts ranged from 0.01 to 0.15 mg/ml in Curcuma zedoaria and from 0.01 to 0.94 mg/ml in Curcuma malabarica. Staphylococcus aureus (Gram positive) was inhibited by Curcuma malabarica but not by Curcuma zedoaria. This study is the first report of the antimicrobial properties of Curcuma malabarica. The findings also support the use of Curcuma zedoaria tubers in traditional medicine for the treatment of bacterial and fungal infections.

Allelic variation of BAT-25 and BAT-26 mononucleotide repeat loci in tumours from a group of young women with breast cancer

Genomic instability in the form of repeat number variation at microsatellite loci has been reported in several human cancers. To resolve current confusion regarding frequency of microsatellite instability (MSI), standardised protocols have proposed use of a consensus set of informative loci; it is claimed that analysis of 2 apparently quasi-homozygous, quasi-monomorphic, mononucleotide repeats (BAT-25 and BAT-26) is sufficiently accurate to define MSI (obviating need for corresponding constitutive DNA). We examined these loci in 163 breast cancers, 108 of which had previously been analysed at 11-24 other loci and found to have MSI in 38% of them. For BAT-26 only 1/153 (homozygous) tumours showed a contracted allele, with minor size variations (1-6 bp) between individuals. For BAT-25 repeat contractions were unambiguously observed in 12 (7.4%) tumours; only 4 of these were previously designated MSI+. DNA from normal individuals showed significant allelic variation in 8/159 (5%) cases for BAT-25; no instance of heterozygosity was seen for BAT-26. Subsequently, we analysed normal DNA from the 12 individuals whose tumours had MSI at BAT-25; in 2 cases there was germline heterozygosity. We conclude that analysis with BAT-26 (in contrast to other loci) was not a useful detector of MSI. With BAT-25, a low frequency of MSI not much greater than germline polymorphism, also limits the utility of this marker for determining MSI in breast cancer.

Simultaneous onset of preseptal cellulitis in monozygotic twins

We report here a rare case of simultaneous onset of preseptal cellulitis in twins. The absence of any infection in three other siblings during this period would suggest that the twins may not have developed simultaneous lid infection by sheer coincidence. The authors discuss the possible mechanism and emphasize the need for close surveillance of the twin of an index case with ocular infection.

Bowel imbrication in the management of anorectal anomalies

Four patients who had imbrication of their proximal rectum and distal sigmoid colon as part of the management of constipation following an anorectoplasty for an anorectal anomaly. Three children with an anorectal anomaly presented with constipation and marked dilation of the rectosigmoid portion of the large bowel; each had longitudinal imbrication of the dilated segment, via a left iliac fossa incision. The forth was born with a cloacal anomaly with associated colonic atresia. The small bowel was used to construct the anorectum following a redo anorectoplasty. Subsequently, the small bowel became ectatic, resulting in the patient developing persistent watery diarrhoea and severe perianal excoriation, which was managed with a 30 cm longitudinal imbrication of the distal bowel during an extensive laparotomy. All 4 have patients now have near normal bowel motions with minimal medication, after only a short hospital stay. Residual problematic dilatation of the rectosigmoid colon in patients with a high anorectal anomaly, in the presence of constipation, can be successfully managed by imbrication of the dilated segment, if carefully selected.

Frequent microsatellite alterations in a predominantly younger age of onset breast cancer population

Microsatellite instability (MSI) and loss of heterozygosity (LOH) was investigated in paired tumour and normal tissue DNA from 108 predominantly premenopausal breast cancer patients (under age 45 years at presentation) for 25 simple repeat loci interspersed across 11 chromosomes. MSI was observed at a single locus in 69 (64%) patients; 41 of these had instability at more than one site. Greatest frequency of MSI was at loci D2S1356 (33%), D2S2739 (22%), D3S1766 (21%) and D13S796 (20%). LOH was seen at a single site in 55% of patients and at two or more sites in 27 patients with greatest frequency at D2S1356 (33%), D2S443 (19%) and D17S1299 (18%). Both mutations were found in the same patient but at different loci. Clearly, choice of loci is a determining factor in assessing genomic instability. The relatively high frequency of MSI may also reflect peculiarities of this younger patient population. Occurrence of MSI or LOH was unrelated to clinical stage, nodal status, tumour size or grade or steroid receptor status. It was independent of mutations detected in exons 5-9 of the p53 gene. There was no significant association with survival. The lack of such correlations reflects a random disabling mechanism that may equally affect genes promoting cell death as well as growth.