The effect of low-level laser irradiation on dog spermatozoa motility is dependent on laser output power.

Biological tissues respond to low-level laser irradiation and so do dog spermatozoa. Among the main parameters to be considered when a biological tissue is irradiated is the output power. We have studied the effects on sperm motility of 655 nm continuous wave diode laser irradiation at different output powers with 3.34 J (5.97 J/cm(2)). The second fraction of fresh dog sperm was divided into five groups: control, and four to be irradiated with an average output power of 6.8 mW, 15.4 mW, 33.1 mW and 49.7 mW, respectively. At 0 min and 45 min after irradiation, pictures were taken and a computer aided sperm analysis (CASA) performed to analyse different motility parameters. The results showed that different output powers affected dog semen motility parameters differently. The highest output power showed the most intense effects. Significant changes in the structure of the motile sperm subpopulation were linked to the different output powers used.

Risk of acute liver injury associated with the use of drugs: a multicentre population survey.

BACKGROUND: Acute liver injury of uncertain aetiology is often drug related and quantitative information about the associated risk is scarce. AIM: To estimate the risk of acute liver injury associated with the use of drugs. METHODS: In a population survey study, 126 cases of acute liver injury were prospectively assembled from January 1993 to December 1999, in patients over 15 years of age, in 12 hospitals in Barcelona (Spain). We estimated the relative risk for each drug as the ratio between the incidence of acute liver injury among the exposed population to the drug and the incidence of acute liver injury among those not exposed to it. Drug consumption data were used to estimate the exposed population. RESULTS: Isoniazid, pyrazinamide, rifampicin, amoxicillin with clavulanic acid, erythromicin, chlorpromazine, nimesulide, and ticlopidine presented the highest risk (point relative risk > 25). Amoxicillin, metoclopramide, captopril and enalapril, furosemide, hydrochlorothiazide, fluoxetine, paroxetine, diazepam, alprazolam, lorazepam, metamizole, low-dose acetylsalicylic acid and salbutamol showed the lowest risk (point relative risk < 5). CONCLUSIONS: This study provides a risk estimation of serious liver disease for various drugs that will be useful in its diagnosis and management, and when comparing with the drug therapeutic benefit in each indication. Some observed associations would be worth specific studies.

The Tub alpha 3 gene from Zea mays: structure and expression in dividing plant tissues.

A gene (Tub alpha 3) coding for an alpha-Tub, expressed in dividing tissues, has been cloned from Zea mays. The deduced amino acid (aa) sequence, 450 aa long, is very similar to the other plant alpha-Tub (85-89% homology) so far reported, and in particular to the other two aa sequences (alpha 1-Tub and alpha 2-Tub) already published from the same species (93% homology). The genomic structure is also very similar, having three introns located at the same positions as in the Tub alpha 1 and Tub alpha 2 genes, one of them placed at the same position in the homologous genes from Arabidopsis thaliana. Nevertheless, the noncoding sequences are very different from the two other maize genomic sequences. In particular, no homology has been found either in the 5' upstream or in the 3'-untranslated sequences. Using specific 3' probes, it has been possible to detect the mRNA coded by this gene in many of the plant organs measured, but its highest abundance is observed in the organs rich in dividing cells, a pattern correlated with that of the histone H4-encoding gene. A cDNA clone has been identified in maize coleoptiles and sequenced, confirming the expression of the Tub alpha 3 in this organ. No preferential accumulation in any organ of the plant was found, in contrast with what was observed in the Tub alpha 1 and Tub alpha 2 genes already described. The Tub alpha gene family seems to consist in maize by at least two groups of homologous sequences, each one including a maximum of two or three coding units.

Multiple polyadenylation sites are active in the alpha 1-tubulin gene from Zea mays.

Two cDNA clones (MR2 and MR29) encoding the same alpha-tubulin isotype (alpha 1) have been identified and characterized from maize roots. The sequence of these two cDNA clones is identical to a previously described cDNA clone (MR19) except in the location of their polyadenylation site. The sequence of the cDNA and its homologous genomic clone (MG19/14) shows two putative polyadenylation signals which could direct the variable 3' processing of the observed transcripts. Endonuclease S1 protection analysis in this 3' flanking region confirms the presence in the alpha 1-tubulin gene from Zea mays of these two main functional polyadenylation sites and possibly other related ones. The relative accumulation of RNAs bearing the two main polyadenylation sites has been tested by using a RNA-slot analysis of several tissues of the plant. It appears that a higher proportion of shorter mRNA species is found in actively dividing tissues.

Clinical and histologic effects of facial skin rejuvenation with pulsed- and continuous-wave flash-scanned CO(2) lasers.

LEARNING OBJECTIVES: The reader is presumed to have some understanding of the use of lasers in skin resurfacing. After studying the article, the participant should be able to: Physicians may earn 1 hour of Category 1 CME credit by successfully completing the examination based on material covered in this article. The examination begins on page 409. BACKGROUND: The selection of the ideal laser for facial resurfacing is debatable. OBJECTIVE: The purpose of the study was to determine whether any clinical and histologic differences existed in short- and long-term results after treatment with the Coherent UltraPulse 5000G laser (a pulsed laser; PL) and the Sharplan Silk Touch laser (a continuous-wave laser [CWL] with a flash scanner). METHODS: Eight patients underwent facial resurfacing treatment on different areas. In each case, one side was treated with the PL and the other with the CWL. The condition of the patients and the treated tissue were monitored periodically after treatment. Histologic assessment of punch biopsies was performed 3 months and 1 year after treatment with hematoxylin-eosin, Masson trichromic, and Verhoeff's stains. RESULTS: The areas treated with the PL achieved earlier epithelialization with a good appearance. Longer-lasting erythema was observed on the side treated with the CWL. On a histologic level, although the PL-treated tissue epithelialized more quickly, at 3 months and 1 year the collagen was better compacted and better aligned in the CWL-treated tissue, and the macroscopic appearance of the CWL-treated areas was more enhanced. CONCLUSIONS: The more active vascularization seen in the CWL-treated tissue, associated with the longer-lasting erythema and possibly greater collateral thermal injury, is possibly the reason for the better collagenization and remodeling of collagen and elastin fibers as compared with the results with the PL-treated tissue. This may explain the longer effect associated with CWL treatment. The clinician would do well to bear in mind the histologic findings as well as the macroscopic clinical results when assessing the long-term effects of laser skin resurfacing. (Aesthetic Surg J 2001;21:399-411.).

Effect of 655-nm diode laser on dog sperm motility.

Sperm motility depends on energy consumption. Low-level laser irradiation increases adenosin triphosphate (ATP) production and energy supply to the cell. The aim of this study is to analyse whether the irradiation affects the parameters that characterise dog sperm motility. Fresh dog sperm samples were divided into four groups and irradiated with a 655-nm continuous-wave diode laser with varying doses: 0 (control), 4, 6 and 10 J/cm(2). At 0, 15 and 45 min following irradiation, pictures were taken of all the groups in order to study motility with computer-aided sperm analysis (CASA). Functional tests were also performed. Average path velocity (VAP), linear coefficient (Lin) and beat cross frequency (BCF) were statistically and significantly different when compared to the control. The functional tests also showed a significant difference. At these parameters, the 655-nm continuous-wave diode laser improves the speed and linear coefficient of the sperm.