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.

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.

Unsupervised self-testing of airway obstruction by forced oscillation at the patient's home.

As active patient cooperation is not required, the forced oscillation technique (FOT) could be suitable for measuring airway obstruction in routine home applications. Nevertheless, FOT has never been used at the patient's home to date. The aim of this study was to assess the feasibility of FOT and the reproducibility of measured respiratory resistance (Rrs) in routine patient self-testing at home. Altogether, nine asthmatic patients self-measured their Rrs with a portable FOT device and spirometry for 10-14 days, in the morning and evening, and before and after bronchodilator inhalation. During each measurement session, the patients carried out four consecutive FOT measurements. Grubbs' discordancy test for detecting outliers was used to evaluate intermeasure reliability. Only 4.9% of Rrs data reported by patients were rejected as artefacts. The coefficient of variation of Rrs was 7.9 +/- 6.3% (mean +/- SD). When compared with spirometry, the per cent change in Rrs for detecting a positive bronchodilator response showed an 83% sensitivity and 72% specificity. Unsupervised self-measurement of respiratory resistance at the patient's home provided results similar to those obtained by a technician in a lung function lab. Forced oscillation technique could be a useful tool for the routine follow-up of asthmatic patients at home.

A portable forced oscillation device for respiratory home monitoring.

The increase in the prevalence of chronic respiratory diseases has resulted in a rise in health services provided at home. The forced oscillation technique (FOT) proves to be a useful tool when it is desired to assess lung function noninvasively, and particularly for patients in whom spirometry cannot be applied. As no portable FOT device is currently available, the aim of this study was to design and test a portable FOT system for ambulatory and home care applications. The system devised is based on a microprocessor, which allows online computation of respiratory resistance (Rrs) and reactance (Xrs) and reliability indices. The portable device was compared with a conventional FOT system by using signals from 14 patients with chronic respiratory disease. This device has the same computation capabilities and flexibility as conventional FOT systems and meets the requirements for home application. Rrs (14.2 +/- 6.0 cmH2O x s x L(-1), mean +/- SD) and Xrs (-5.3 +/- 2.7 cmH2O x s x L(-1)) measured at 5 Hz by the portable system virtually coincided with those computed with the reference conventional FOT system: mean differences +/-SD were 0.074 +/- 0.025 and 0.005 +/- 0.009 cmH2O x s x L(-1), respectively. This portable forced oscillation technique device could be a useful tool for monitoring respiratory mechanics in ambulatory and home care applications.

Immunogold localization of a transglutaminase related to grana development in different maize cell types.

A comparative study of the subcellular localization of a plant transglutaminase (TGase; EC 2.3.2.13) in various in vivo and in vitro maize cell types was carried out with a polyclonal antibody raised against a 58 kDa TGase purified from Helianthus tuberosus leaves. Immunocytochemical staining, followed by electron microscopy, showed that this enzyme was markedly present in the grana-appressed thylakoids of mature chloroplasts of the light-exposed cells. Moreover, during embryogenic callus chloroplast differentiation, the abundance of TGase in the grana-appressed thylakoids depended on the degree of grana development and was greater than in mature leaf chloroplasts. In addition to the 58 kDa form, two other forms of the protein (of 77 and 34 kDa) were obtained by Western blot. The 77 kDa form might correspond to the inactive form and was immunodetected in dense vesicles observed in dark-grown embryogenic callus cells. In adult leaves, the enzyme was also markedly present in the grana-appressed thylakoids of the mesophyll cell chloroplasts, though very scarce and dispersed in the bundle-sheath cell chloroplasts (which do not contain grana). The concordance of these localizations with those described for the light-harvesting antenna proteins of the photosystem II suggests that it is possible that this TGase has a functional role in photosynthesis, perhaps modulating the photosynthetic efficiency and the absorption of excess light by means of polyamine conjugation to the antenna proteins.

Comparison of the low level laser therapy effects on cultured human gingival fibroblasts proliferation using different irradiance and same fluence.

BACKGROUND AND OBJECTIVE: The low level laser therapy (LLLT) has been used in Dentistry to improve wound healing. In order to analyse the effect of LLLT on the in vitro proliferation of gingival fibroblasts we developed a primary culture of human gingival fibroblasts. STUDY DESIGN/MATERIALS AND METHODS: The cell line named LMF was grown in Dulbecco's Modified Eagle's medium (DME) with either 5% (nutritional deficit) or 10% fetal bovine serum (fbs). Laser irradiation was carried out with diode lasers with the following wavelengths: 670 nm (L1), 780 nm (L2), 692 nm (L3), and 786 nm (L4). The fluence was fixed in 2 J/cm(2). For growth analysis, control (not irradiated) and treated cultures (irradiated) were plated in 60 mm diameter culture dishes for 12 h before the irradiation. RESULTS: We found that cells cultured in nutritional deficit condition grown in medium supplemented by only 5% fbs presented a cell proliferation rate significantly smaller that cell grown in ideal culture conditions (10% fbs). However, when irradiated, cells in nutritional deficit presented cell growth similar or higher than that of control cells grown in ideal culture conditions. Using the same fluence, the infrared laser induced a higher cell proliferation than visible laser when the power outputs were different. However, lasers of equal power output presented similar effect on cell growth independently of their wavelengths. CONCLUSIONS: The LLLT acts by improving the in vitro fibroblast proliferation and a smaller laser exposure time results in higher proliferation.

Forced oscillation measurements do not affect upper airway muscle tone or sleep in clinical studies.

Upper airway obstruction in the sleep apnoea/hypopnoea syndrome (SAHS) can be easily assessed by measuring respiratory impedance with the forced oscillation technique (FOT). This methodology has been proposed as a useful clinical tool both for the diagnosis of sleep breathing disorders and for continuous positive airway pressure (CPAP) titration. However, previous studies suggest that the application of high-frequency pressure oscillation to the upper airway may induce changes in the electroencephalogram (EEG) or upper airway muscle function. The effect of FOT measurements on upper airway muscle tone and EEG in clinical sleep studies was examined. Seven patients with moderate SAHS were included (age: 54+/-11 yrs; apnoea/hypopnoea index: 43+/-21 events x h(-1); body mass index: 30+/-2 kg x m(-2)). Genioglossus surface electromyogram activity (EMGgg) and EEG signal were analysed with and without FOT application (frequency: 5 Hz and 30 Hz; peak-to-peak pressure oscillation: 1 cmH2O) during stable sleep. Measurements were carried out in two different situations. Step 1: applying FOT during episodes of obstructive events or flow limitation; and step 2: during prolonged periods of normal breathing at optimal CPAP. The root mean square of EMGgg activity and fast Fourier analysis (alpha and delta bands) of the EEG signal were performed. The application of FOT did not increase EMGgg activity in any of the situations studied. In addition, no evidence of the effects on EEG was found: alpha/delta relationship: awake:0.70, baseline sleep:0.13, FOT(5 Hz):0.18, FOT(30 Hz):0.11. The presented results suggest that the use of forced oscillation technique over the ranges of frequency and amplitude proposed for clinical sleep studies does not induce changes in upper airway muscle activity and neurological variables in patients with sleep apnoea/hypopnoea syndrome.

Evaluation of a simplified oscillation technique for assessing airway obstruction in sleep apnoea.

The forced oscillation technique (FOT) is a noninvasive method that is useful for assessing airway obstruction and for titrating continuous positive airway pressure (CPAP) in patients with sleep apnoea. The aim was to evaluate the routine applicability of a simplified FOT set-up based on recording pressure and flow at the level of the CPAP device, i.e. obviating the need for connecting the transducers to the nasal mask. A correction to account for the tubing and the exhaust port was applied. This simplified FOT was evaluated on nine patients with moderate or severe sleep apnoea during routine CPAP titration. Patient impedance measured by the simplified FOT ([Z]) was compared with actual patient impedance ([Zrs]) measured simultaneously with a reference FOT based on recording pressure and flow at the nasal mask. An excellent agreement was found between [Z] and [Zrs] over the wide range of airway obstruction explored (4.8-72.1 cmH2O x s x L(-1)): [Z] = [Zrs] x 0.86 + 1.3 cmH2O x s x L(-1) (r = 0.99). Moreover, the simplified and the conventional FOT settings detected the same respiratory events during sleep. These results demonstrate that this simplified FOT is applicable for measuring airway obstruction during routine sleep studies in patients with sleep apnoea.

Relevance of linearizing nasal prongs for assessing hypopneas and flow limitation during sleep.

Respiratory disturbances in patients with the sleep apnea-hypopnea syndrome (SAHS) may be detected by means of nasal prongs (NP) pressure (PNP). Nevertheless, PNP is nonlinearly related to flow (V). Our aim was to demonstrate the relevance of linearizing P NP for assessing hypopneas and flow limitation in SAHS. V was measured with a pneumotachograph during the hypopneas and flow limitation events in a continuous positive airway pressure (CPAP) titration in six patients with severe SAHS. These flow patterns were reproduced by a flow generator through an analog of the nares and recorded by NP. PNP was linearized [V NP = (PNP)1/2] by a specially designed analog circuit. For each event we used V, P NP, and V NP to compute the hypopnea flow amplitude (HFA) and a flow limitation index (FLI). Owing to NP nonlinearity, PNP considerably misestimated HFA and FLI. By contrast, V NP provided HFA and FLI values that were very close to those obtained from V: HFA (V NP) = 1.098. HFA(V) - 0.063 (r2 = 0.98) and FLI(V NP) = 1.044. FLI(V) + 0.004 (r2 = 0.99). Square-root linearization of NP greatly increases the accuracy of quantifying hypopneas and flow limitation. This procedure, which could be readily carried out in routine practice by means of the analog circuit we developed, is of interest in optimizing the assessment of respiratory sleep disturbances in SAHS.

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.).

Effects of skin cleaning modes on the condition of collagen and elastin after laser resurfacing.

BACKGROUND: Laser resurfacing is now widely used for the treatment of facial wrinkles, photoaging and acne scars and is usually combined with comparatively aggressive methods of cleaning detritus off the treated area after each laser pass. OBJECTIVE: This study aims to evaluate two different cleaning methods (damp gauze or damp large-tip cotton buds) in order to elucidate their influence on the healing process, if any. The left or right preauricular area, chosen at random on 10 patients undergoing periocular and perioral resurfacing with the same laser system, was cleaned after each laser pass with damp gauze (Group G) and the contralateral side with the large-tip cotton buds (Group C). Post-resurfacing oedema and erythema were observed in the preauricular areas and rated by the same experienced observer immediately after treatment and at 14, 30, 45, 60 and 90 days. RESULTS: Oedema was slightly more noticeable initially in Group G patients, but the erythema was more intense and lasted longer in the gauze-cleaned tissue. The sites were biopsied at 90 days and the samples sent for blinded histological evaluation to assess the degree of collagen and elastin fibre compaction. The histology demonstrated that the tissue from Group G achieved, at 90 days, better compaction of collagen and elastin fibres than that from Group C. CONCLUSIONS: It is suggested that the abrasive action caused by the gauze adds to the existing stimulative inflammatory reaction following CO2 laser resurfacing, which augments the collagen and fibre compaction response in the tissue. Comparatively aggressive cleaning with damp gauze may therefore be preferable to other methods when performing laser resurfacing.

Involvement of a maize proline-rich protein in secondary cell wall formation as deduced from its specific mRNA localization.

A clone encoding a proline-rich protein (ZmPRP) has been obtained from maize root by differential screening of a maturing elongation root cDNA library. The amino acid sequence deduced from the full-length cDNA contains a putative signal peptide and a highly repetitive sequence containing the PEPK motif, indicating that the ZmPRP mRNA may code for a cell wall protein. The PEPK repeat is also found in a previously reported wheat sequence but differs from the repeated sequences found in hydroxyproline-rich glycoproteins (HRGP) and in dicot proline-rich proteins (PRP). In the maize genome, the ZmPRP protein is encoded by a single gene that is expressed in maturing regions of the root, in the hypocotyl and in the pericarp. In these organs, the ZmPRP mRNA accumulates in the xylem and surrounding cells, and in the epidermis. No ZmPRP mRNA was found in the phloem. The pattern of mRNA accumulation is very similar to the one observed for genes coding for proteins involved in lignin biosynthesis and, like most cell wall proteins, ZmPRP synthesis is also induced by wounding. These data support the hypothesis that ZmPRP is a member of a new class of fibrous proteins involved in the secondary cell wall formation in monocot species.

Electron microscopy comparison of CO2 laser flash scanning and pulse technology one year after skin resurfacing.

BACKGROUND: The recent adaptation of laser technology in plastic and dermatologic surgery has provided a means to reduce efficiently the irregularities of the surface of the skin. Previous studies have analyzed the short- and medium-term clinical and histologic results of two laser systems: the Sharplan 40C SilkTouch and the 5000C Coherent Ultrapulse with Computer Pattern Generator (CPG). This paper contains the long-term ultrastructural findings observed with the aid of transmission electron microscopy (TEM). MATERIALS AND METHODS: Twenty skin biopsy specimens were taken from ten Caucasion patients, between 54 and 72 years of age, who had undergone facial skin resurfacing with a CO2 laser 1 year previously. The treated areas of the face were divided into two equal parts. One half of the face was treated with the Sharplan SilkTouch laser and the other half with the Coherent Ultrapulse laser. Using TEM, the cell composition of the epidermis was studied ultrastructurally, as were the dermal-epidermal junction (DEJ) and the different fibers and cells in the superficial and middle dermis. RESULTS: On the side treated by the Sharplan laser, little melanin was observed, the DEJ was thicker, and there were abundant collagen fibers well compacted in the dermis. Also present was abundant elastin fiber with scarce interstitial spaces. On the side treated by the Coherent, the melanin was abundant and the DEJ was well structured. There were fibroblasts with lax chromatin in the dermis and collagen fibers in the papillary dermis oriented in a vertical and horizontal manner in relation to the epidermis. There was little elastin. The interstitial spaces were abundant. CONCLUSIONS: The Sharplan laser system seems to provoke a significantly more intense tissue response, with abundant dermal collagen and elastic fibers. This indicates that the Sharplan 40C SilkTouch might produce longer lasting clinical effects.

The filtrum remodelling with combined Er:YAG CO2 laser resurfacing.

BACKGROUND: Upper lip wrinkles develop with aging and they can be successfully treated with laser resurfacing. The treatment eliminates the wrinkles and, ideally, should also recover the aesthetic configuration. METHODS: This report includes 32 patients treated for wrinkles of the upper lip with the Derma K. The first pass was done using 29 J/cm2, 5 Hz, 3 mm collimated spot size, plus the CO2 laser 5 W, 50% duty cycle, 50% overlapping. Following this pass, Derma K was reprogrammed to emit only with the Er:YAG at 1.4 J/cm2, 10 Hz, approximately 50% overlapping and with a beam diameter of 3 mm. Then, several passes were done where wrinkles could still be seen, focusing on the area corresponding to the filtrum. Biopsies were taken to examine possible particular implications of underlying muscle and its role in the recovery of anatomic aesthetics of young lip characteristics when using the proposed technique. RESULTS: Using Derma K resurfacing with extra passes of the Er:YAG at relatively low density, at the aforementioned area, it was possible to achieve the recovery of the aesthetic youthful appearance of the upper lip. Also, the shape of the filtrum recovered its youthful appearance together with the cupid's bow shape. Histology samples collected at the end of resurfacing showed that the laser thermal effect was also related to muscle fibres due to the proximity of this layer to the dermis because of the narrow subcutaneous fat layer. CONCLUSION: The combination of Er:YAG and CO2 laser of Derma K has potential to enhance the results of resurfacing for elimination of wrinkles of the upper lip. Moreover, the fact that only one laser pass of high energy density is used permits clear and secure control of treatment, preventing complications and obtaining good results.

Maize alpha-tubulin genes are expressed according to specific patterns of cell differentiation.

In the past few years many alpha- and beta-tubulin genes of different organisms have been cloned and studied, and in most systems studied they constitute multigene families. In plants, most studies have been done in Arabidopsis thaliana and Zea mays. In this paper, the study of mRNA accumulation by in situ hybridization and the activity of three maize alpha-tubulin gene promoters (tua1, tua2 and tua3) in transgenic tobacco plants are described. In maize, the expression of these three tubulin isotypes differ in the root and shoot apex and is associated with different groups of cells throughout the distinct stages of cell differentiation. In transgenic tobacco plants the promoters of the genes, fused to the uidA reporter gene (GUS), direct expression to the same tissues observed by in situ hybridization experiments. The tua1 promoter is mainly active in cortex-producing meristematic cells and in pollen, whereas tua3 is active in cells which are differentiating to form vascular bundles in the root and shoot apices. The accumulation of tua2 mRNA is detected by RNA blot in a similar form as tua1, but at a very much low level. In situ hybridization indicates that the tua2 mRNA specifically accumulates in the maize root epidermis. No GUS staining was detected in transgenic tobacco plants with the tua2 promoter. The difference in expression of the specific genes may be linked to processes where microtubules have different functions, suggesting that in plants, as in animals, there are differences in the function of the tubulin isotypes.