[Molecular epidemiology and antibiotic resistance of Pseudomonas aeruginosa isolated from blood in a hospital in Shandong Province from 2014 to 2021]

Objective: To identify the antibiotic resistance, virulence genes, and sequence types of Pseudomonas aeruginosa (P. aeruginosa) strains isolated from blood. Methods: From November 2014 to December 2021, a total of 94 nonrepetitive P. aeruginosa isolates were obtained from blood samples of patients at the First Affiliated Hospital of Shandong First Medical University in Shandong Province, China. The bacteria were identified using matrix-assisted laser desorption ionization time of flight mass spectrometry. Antibiotic resistance of the P. aeruginosa isolates was detected using Vitek 2 Compact system. Polymerase chain reaction (PCR) was conducted for the 18 virulence genes, and multi locus sequence typing (MLST) was performed to identify the sequence types of the P. aeruginosa strains. The resistance rates and distributions of virulence genes between carbapenem resistant pseudomonas aeruginosa (CRPA) and carbapenem susceptible pseudomonas aeruginosa (CSPA) isolates were compared using the Chi-square test. Results: Among 94 P. aeruginosa isolates, 19 (20.2%) isolates were found to be multidrug resistant (MDR) bacteria, of which 17 were CRPA isolates and 2 were CSPA isolates. All strains contained more than 10 virulence genes. Except for exoU gene, the detection rate of other genes was above 83%. MLST analysis revealed a total of 66 different STs, including 59 existing STs and 7 novel STs. Among them, ST244 (n=11, 11.7%) and ST270 (n=7, 7.4%) were the dominant STs. Although these two types of isolates harbored the same virulence genes, the resistance rates to carbapenem were different. 54.5% (6/11) ST244 isolates were CRPA but all 7 ST270 isolates were CSPA. Conclusion: Although the resistance rates of P. aeruginosa strains isolated from blood were at a low level, some MDR and CRPA isolates were detected. As the high virulence gene detection rates and genetic diversity were found for P. aeruginosa strains isolated from blood, close attention should be paid to avoid transmission and outbreaks.

[Questionnaire survey analysis on the screening of tuberculosis among diabetic patients in general hospitals of Hunan Province]

Objective: To investigate the development of tuberculosis screening-related tests in general public hospitals(GPHs) of different levels in Hunan Province and the"awareness and practice of screening tuberculosis in diabetic patients"by doctors directly involved in diabetes diagnosis and treatment in the hospitals, aiming to provide reference for the formulation of the tuberculosis-diabetes joint prevention and control activity plan based on our national conditions. Methods: Stratified sampling was used to select 43 GPHs at three different levels in Hunan province: 14 tertiary GPHs, 13 secondary GPHs, and 16 primary GPHs. 284 endocrinologists working in enrolled hospitals were invited to participate in the on-site questionnaire-survey and 277 qualified. The study used SPSS 22.0 statistical software to analyze the data. The prevalence rate of tuberculosis screening test among hospitals at all levels was compared by chi-square test, and logistic regression was used to analyze the related factors affecting doctors' screening awareness. P≤0.05 was considered statistically significant. Results: The allocation of digital X-ray cameras, tuberculin skin tests, sputum acid-fast bacillus smears, sputum cultures for Mycobacterium tuberculosis, and interferon-gamma release assays in the 43 GPHs were 90.7% (39/43), 72.1% (31/43), 55.8% (24/43), 34.9% (15/43), 27.9% (12/43) with significant differences between the different hospital levels(P<0.05). 173 endocrinologists considered it necessary to proactively initiate tuberculosis screening for patients at first diagnosis. When admitting patients, 197 endocrinologists chose tuberculosis screening only for diabetes mellitus patients with suspected tuberculosis symptoms. The most possible reasons why diabetes mellitus patients wouldn't undergo tuberculosis screening were"patients refused(76.5%, 212/277)","patients didn't complain of the symptom(46.9%, 130/277)", and"tuberculosis screening-related tests haven't been conducted in the hospital(35.7%, 99/277)". Conclusions: Although endocrinologists displayed some tuberculosis-related knowledge and awareness of the need for proactive tuberculosis screening, the actual screening rate in the clinical setting was low. This may be related to multiple factors, including those of patients, doctors, and medical institutions.

Cohesive properties of PbBi/Fe3O4 and PbBi/(Fe,Cr)3O4 interfaces

First principles calculations reveal that the effects of PbBi on the cohesive properties of Fe₃O₄ and (Fe,Cr)₃O₄: PbBi can reduce the cohesive strength of the oxides, and the contents of O and Cr on the O-terminated oxide side play a significant role in the cohesive properties of the PbBi/Fe₃O₄ and PbBi/(Fe,Cr)₃O₄ interfaces. Specifically, the performance of oxidation decreases more significantly under the conditions of insufficient oxygen, and a high ratio of Cr of the subsurface of oxides can lead to the reduction of the cohesive properties of O-terminated interfaces. Calculations also show that the Pb-O-terminated interfaces are energetically favorable and are more stable than the Bi-O-terminated surfaces due to the strong bond of Pb-O, while the Bi-Cr and Bi-Fe interfaces are more stable than the Pb-Cr and Pb-Fe interfaces. Moreover, it is found that the stability and cohesion of the PbBi/Fe₃O₄ and PbBi/(Fe,Cr)₃O₄ interfaces will decrease when the oxygen concentration is insufficient or the degree of wetting of PbBi of oxides is low, and the PbBi/Fe₃O₄ interface is more sensitive to these conditions. The bond-dissociation energies and electronic structures provide a deep understanding of various interface properties, and the obtained results are in good agreement with experimental measurements in the literature.

ORAOV1-B Promotes OSCC Metastasis via the NF-κB-TNFα Loop

Metastasis, a powerful prognostic indicator of oral squamous cell carcinoma (OSCC), is chiefly responsible for poor cancer outcomes. Despite an increasing number of studies examining the mechanisms underlying poor outcomes, the development of potent strategies is hindered by insufficient characterization of the crucial regulators. Long noncoding RNAs (lncRNAs) have recently been gaining interest as significant modulators of OSCC metastasis; however, the detailed mechanisms underlying lncRNA-mediated OSCC metastasis remain relatively uncharacterized. Here, we identified a novel alternative splice variant of oral cancer overexpressed 1 (ORAOV1), named as ORAOV1-B, which was subsequently validated as an lncRNA and correlated with OSCC lymph node metastasis; significantly increased invasion and migration were observed in ORAOV1-B-overexpressing OSCC cells. RNA pulldown and mass spectrometry identified Hsp90 as a direct target of ORAOV1-B, and cDNA microarrays suggested TNFα as a potential downstream target of ORAOV1-B. ORAOV1-B was shown to directly bind to and stabilize Hsp90, which maintains the function of client proteins, receptor-interaction protein, and IκB kinase beta, thus activating the NF-κB pathway and inducing TNFα. Additionally, TNFα reciprocally enhanced p-NF-κB-p65 and the downstream epithelial-mesenchymal transition. ORAOV1-B effects were reversed by a TNFα inhibitor, demonstrating that TNFα is essential for ORAOV1-B-regulated metastatic ability. Consistent epithelial-mesenchymal transition in the ORAOV1-B group was demonstrated via an orthotopic model. In the metastatic model, ORAOV1-B significantly contributed to OSCC-related lung metastasis. In summary, the novel splice variant ORAOV1-B is an lncRNA, which significantly potentiates OSCC invasion and metastasis by binding to Hsp90 and activating the NF-κB-TNFα loop. These findings demonstrate the versatile role of ORAOV1 family members and the significance of genes located within 11q13 in promoting OSCC. ORAOV1-B might serve as an attractive OSCC metastasis intervention target.

A hydrophobic polymer stabilized CsPbBr3 sensor for environmental pollutant detection

The detection of o-nitrophenol in the environment is of great significance to environmental protection.

Visual monitoring of trace water in organic solvents based on ecofriendly b/r-CDs ratiometric fluorescence test paper

Developing a green, non-toxic and easy to synthesize of fluorescence probe for fast and visual detecting trace water in various organic solvents was an important task. Here, a novel dual-emission fluorescence probe (b/r-CDs) was designed based on the red CDs (r-CDs) and blue CDs (b-CDs) to detect the trace water and enhance the visualization for naked-eye observation in different organic solvents. Among, the red fluorescence carbon dots (CDs) was found to have the capability to monitor trace amounts of water, which synthesized with green tea by facile ultrasonic method. Further, Such a dual-emission probe could fast monitor trace water in various organic solvents with high stability and fast response. Importantly, a synergistic mechanism of the dynamic process (b-CDs) and static quenching (r-CDs) was proved for the study of water detection. Moreover, the test paper was made for detecting trace water in different organic solvents, achieving convenient and effective detection.

Translational outcomes in a full gene deletion of ubiquitin protein ligase E3A rat model of Angelman syndrome

Angelman syndrome (AS) is a rare neurodevelopmental disorder characterized by developmental delay, impaired communication, motor deficits and ataxia, intellectual disabilities, microcephaly, and seizures. The genetic cause of AS is the loss of expression of UBE3A (ubiquitin protein ligase E6-AP) in the brain, typically due to a deletion of the maternal 15q11-q13 region. Previous studies have been performed using a mouse model with a deletion of a single exon of Ube3a. Since three splice variants of Ube3a exist, this has led to a lack of consistent reports and the theory that perhaps not all mouse studies were assessing the effects of an absence of all functional UBE3A. Herein, we report the generation and functional characterization of a novel model of Angelman syndrome by deleting the entire Ube3a gene in the rat. We validated that this resulted in the first comprehensive gene deletion rodent model. Ultrasonic vocalizations from newborn Ube3am-/p+ were reduced in the maternal inherited deletion group with no observable change in the Ube3am+/p- paternal transmission cohort. We also discovered Ube3am-/p+ exhibited delayed reflex development, motor deficits in rearing and fine motor skills, aberrant social communication, and impaired touchscreen learning and memory in young adults. These behavioral deficits were large in effect size and easily apparent in the larger rodent species. Low social communication was detected using a playback task that is unique to rats. Structural imaging illustrated decreased brain volume in Ube3am-/p+ and a variety of intriguing neuroanatomical phenotypes while Ube3am+/p- did not exhibit altered neuroanatomy. Our report identifies, for the first time, unique AS relevant functional phenotypes and anatomical markers as preclinical outcomes to test various strategies for gene and molecular therapies in AS.

Functional characterization of ultraspiracle in Leptinotarsa decemlineata using RNA interference assay

A heterodimer of ultraspiracle (USP) and ecdysone receptor (EcR) mediates 20-hydroxyecdysone (20E) signalling cascade to regulate insect moulting and metamorphosis. However, at least two questions remain to be addressed in terms of the molecular importance of USP in insect species. First, is USP involved in both regulation of ecdysteroidogenesis and mediation of 20E signalling in non-drosophilid insects, as in Drosophila melanogaster? Second, does USP play any role in larval metamorphosis except as the partner of heterodimeric receptor to activate the downstream 20E signalling genes? In this paper, we found that RNA interference (RNAi) of LdUSP in the final (fourth) instar larvae reduced the messenger RNA levels of four ecdysteroidogenesis genes (Ldspo, Ldphm, Lddib and Ldsad) and 20E titre, and repressed the expression of five 20E signal genes (EcRA, HR3, HR4, E74 and E75) in Leptinotarsa decemlineata. The LdUSP RNAi larvae remained as prepupae, with developing antennae, legs and discs of forewings and hindwings. Dietary supplement with 20E restored the expression of the five 20E signal genes, but only partially alleviated the decreased pupation rate in LdUSP RNAi beetles. Knockdown of LdUSP at the penultimate (third) instar larvae did not affect third-fourth instar moulting. However, silencing LdUSP caused similar but less severe impairments on pupation. Accordingly, we propose that USP is undoubtedly necessary for ecdysteroidogenesis, for mediation of 20E signalling and for initiation of metamorphosis in L. decemlineata.

Impairment of pupation by RNA interference-aided knockdown of Broad-Complex gene in Leptinotarsa decemlineata (Say)

Dietary delivery of bacterially expressed double-stranded RNA (dsRNA) has a great potential for management of Leptinotarsa decemlineata. An important first step is to discover possible RNA-interference (RNAi)-target genes effective against larvae, especially the old larvae. In the present paper, five putative Broad-Complex (BrC) cDNAs (Z1-Z4, and Z6) were identified in L. decemlineata. The expression of the five LdBrC isoforms was suppressed by juvenile hormone signaling, whereas the transcription was upregulated by 20-hydroxyecdysone signaling at the fourth (final) instar larval stage. Feeding of bacterially expressed dsBrC (derived from a common fragment of the five LdBrC variants) in the third- and fourth-instar larvae successfully knocked down the target mRNAs. For the fourth-instar LdBrC RNAi hypomorphs, they had a higher larval mortality compared with the controls. Moreover, most dsBrC-fed beetles did not pupate normally. After removal of the apolysed larval cuticle, a miniature adult was found. The adult head, compound eyes, prothorax, mesothorax, metathorax were found on the dorsal view. Distinct adult cuticle pigmentation was seen on the prothorax. The mouthparts, forelegs, midlegs, and hindlegs could be observed on the ventral view of the miniature adults. For the third-instar LdBrC RNAi specimens, around 20% moribund beetles remained as prepupae and finally died. Therefore, LdBrC is among the most attractive candidate genes for RNAi to control the fourth-instar larvae in L. decemlineata.

Network Analysis of Y-STR in Six Ethnic Populations in Guangxi and Its Forensic Significances

Abstract

Objective To explore the distribution of genetic structure of Y-SNP and Y-STR genetic markers in different ethnic groups and its application in forensic science. Methods SNaPshot minisequencing was used to detect the polymorphisms of 12 Y-SNP loci in 439 males from 6 ethnic groups, including Guangxi Han, Guangxi Jing, Guangxi Miao, Guangxi Yao, Guangxi Zhuang and Guangxi Dong. DNATyperTM Y26 kit was used to multiplex-amplify 26 Y-STR loci. The PCR products were analyzed by 3130xl genetic analyzer. The network analysis of Y-STR haplotype under the same Y-SNP haplogroup was analyzed by Network 5.0 software. Results Six haplogroups defined by 12 Y-SNP loci were detected in 6 ethnic groups, and 362 haplotypes were detected in 26 Y-STR loci. The haplotype diversity was 0.996 6. In the C haplogroup, the samples from Guangxi Yao, Guangxi Zhuang and Guangxi Dong were clustered on different branches; in the O1 haplogroup, those from Guangxi Zhuang, Guangxi Miao and Guangxi Jing were relatively independent and clustered separately; in the O2 haplogroup, some samples from Guangxi Miao and Guangxi Yao were gathered in a cluster. Conclusion Based on the Y-STR network analysis of samples with identical haplogroup of Y-SNP, some ethnic groups can be preliminarily distinguished, which could be used to infer male suspects' ethnic group through detecting their genetic markers left in the crime scene.

Genetic Polymorphism of Y Chromosome Haplogroup D-M174 in East Asian Populations

Abstract

Objective To explore the genetic polymorphism of Y chromosome D-M174 haplogroup and sub-haplogroups in East Asia. Methods The samples of 1 426 unrelated male individuals from East Asia were collected, and then 7 Y chromosome haplogroup D-M174 and the Y-SNP of its sub-haplogroups were detected with mini-sequencing. The 22 Y-STR genotypes were detected with DNA Typer™ Y26 kit. The haplogroup was analyzed using direct counting method, heatmap, phylogenetic cluster and network graph cluster, and then distribution of genetic polymorphism and the clustering relation between populations and samples of Y chromosome D haplogroup were discussed. Results Haplogroup D-M174 were distributed mostly among Tibetans （40.96%）and Japanese （35.71%）, while less or none were distributed among the surrounding areas of Tibet and other areas. Conclusion The geographical distribution of Y chromosome D-M174 haplogroup in East Asian populations has significant characteristics.

Isoform specific roles of Broad-Complex in larval development in Leptinotarsa decemlineata

Broad-Complex (BrC) is a downstream target of both 20-hydroxyecdysone and juvenile hormone signalling. BrC regulates morphogenetic changes between nymphal instars in hemimetabolans, whereas it controls pupal commitment, pupal morphogenesis and inhibits adult differentiation in holometabolans. Among five BrC cDNAs (Z1-Z4 and Z6) identified in the Colorado potato beetle, we found in this work that Z1, Z2 and Z6 were mainly expressed at the last (fourth) instar and prepupal stages, whereas the levels of Z3 and Z4 increased during the penultimate (third) instar stage, peaked at the last instar larval phase and gradually decreased at the prepupal and pupal periods. When knocking down all BrC isoforms by RNA interference (RNAi) at the penultimate instar stage, around 20% of the resultant larvae remained as moribund beetles. These moribund BrC RNAi larvae were completely or partially wrapped in old cuticle. Likewise, a portion of larvae treated for a single double-stranded RNA of Z3, Z4 or Z6 displayed a degree of similar aberrancies, increasing in the order of isoforms Z6 < Z3 < Z4. When silencing all BrC isoforms at the last instar period, most of the RNAi larvae did not normally pupate or emerge as adults. Separately silencing each of the five zinc finger domains revealed that approximately 70% of the Z1 RNAi larvae remained as prepupae, around 60% of the Z6 RNAi specimens formed aberrant prepupae or pupae and about 60% of the Z2 RNAi beetles became deformed pupae. After removal of the old exuviae, these deformed larvae in which either Z1, Z2 or Z6 was depleted possessed adult prothorax and mesothorax, developing antenna, mouthparts and wing discs. Moreover, less than 50% of the resultant pupae finally emerged as adults when either of Z1, Z2 or Z6 was knocked down. Therefore, our findings reveal, for the first time, that the two roles of BrC in insect groups (ie directing morphogenetic changes during juvenile development and regulating larval-pupal-adult metamorphosis) are played by different BrC isoforms in Leptinotarsa decemlineata.

[Regulation mechanism of E2F1 transcription factor on M2 macrophages in full-thickness skin defect wounds of mice]

Objective: To explore the regulatory mechanism of E2F1 transcription factor on M2 macrophages in full-thickness skin defect wounds of mice. Methods: E2F1 gene knockout heterozygotes C57BL/6 mice and wild-type C57BL/6 mice were introduced and self-reproduced. Two weeks after birth, E2F1 gene knockout homozygotes mice and wild-type mice were identified by polymerase chain reaction (PCR). Twelve identified 6-8 weeks old male E2F1 gene knockout homozygotes C57BL/6 mice and wild-type C57BL/6 mice were selected respectively according to the random number table and set as E2F1 gene knockout group and wild-type group. A full-thickness skin defect wound was made on the back of each mouse. On post injury day (PID) 2 and 7, 6 mice in each group were selected according to the random number table and sacrificed, and the wound tissue was excised. The expression of CD68 and CD206 double positive M2 macrophages was observed by immunofluorescence method, and the percentage of CD206 positive cells was calculated. The protein expression of CD206 was detected by Western blotting. The mRNA expression of arginase 1 was detected by real-time fluorescent quantitative reverse transcription PCR (RT-PCR). Wound tissue specimens of the two groups on PID 7 were obtained, and the protein and mRNA expressions of peroxisome proliferator-activated receptor gamma (PPAR-γ) were detected by Western blotting and real-time fluorescent quantitative RT-PCR respectively. The above-mentioned experiments were repeated four times. Three specimens of wound tissue of mice in wild-type group on PID 7 were obtained to detect the relationship between E2F1 and PPAR-γ by co-immunoprecipitation and Western blotting, and this experiment was repeated two times. Data were processed with unpaired t test. Results: The size of PCR products of E2F1 gene knockout homozygotes C57BL/6 mice and wild-type C57BL/6 mice were 227 and 172 bp respectively, which were the same as those of the designed DNA fragments. On PID 2 and 7, the number of CD68 and CD206 double positive M2 macrophages in the wound tissue of mice in E2F1 gene knockout group was more than that of wild-type group, and the percentages of CD206 positive cells in the wound tissue of mice in E2F1 gene knockout group were (0.234±0.032)% and (0.584±0.023)% respectively, which were significantly higher than (0.129±0.017)% and (0.282±0.071)% of wild-type group (t=3.29, 3.54, P<0.05). On PID 2 and 7, the protein expression of CD206 in the wound tissue of mice in E2F1 gene knockout group were 1.00±0.23 and 1.63±0.26 respectively, which were significantly higher than 0.43±0.06 and 0.97±0.08 of wild-type group (t=2.41, 2.45, P<0.05). On PID 2 and 7, the mRNA expressions of arginase 1 in the wound tissue of mice in E2F1 gene knockout group were 0.482±0.105 and 0.195±0.031 respectively, which were significantly higher than 0.163±0.026 and 0.108±0.017 of wild-type group (t=3.04, 2.86, P<0.05). On PID 7, the protein and mRNA expressions of PPAR-γ in the wound tissue of mice in E2F1 gene knockout group were 0.61±0.12 and 0.51±0.13 respectively, which were significantly higher than 0.20±0.04 and 0.20±0.04 of wild-type group (t=3.36, 2.86, P<0.05). On PID 7, detection of the wound tissue of mice in wild-type group showed that PPAR-γ had unidirectional effect on E2F1. Conclusions: E2F1 transcription factor affects the polarization of M2 macrophages by inhibiting the expression of PPAR-γ, thereby inhibiting the healing process of full-thickness skin defect wounds in mice.

Requirement of Leptinotarsa decemlineata gene within the 74EF puff for larval-pupal metamorphosis and appendage growth

Two Drosophila melanogaster E-twenty-six domain transcription factor isoforms (E74A and E74B) act differentially at the start of the 20-hydroxyecdysone (20E) signalling cascade to regulate larval-pupal metamorphosis. In the present paper, we identified the two isoforms (LdE74A and LdE74B) in Leptinotarsa decemlineata. During the larval development stage, the mRNA transcript levels of the two LdE74 isoforms were correlated with circulating 20E titres. In vitro midgut culture and in vivo dietary supplementation with 20E revealed that the presence of 20E induced expression peaks of both LdE74A and LdE74B, with similar patterns observed for the two isoforms. Moreover, the mRNA transcript levels of both LdE74A and LdE74B isoforms were significantly downregulated in the L. decemlineata ecdysone receptor RNA interference (RNAi) specimens, but not in the LdE75 RNAi beetles. Ingestion of 20E reduced the larval fresh weights and shortened the larval development period, irrespective of knockdown of LdE74 or not. RNAi of LdE74 did not affect 20E-induced expression of the Ecdysone induced protein 75-hormone receptor 3-fushi tarazu factor 1 (E75-HR3-FTZ-F1) transcriptional cascade. Thus, it seems that LdE74 mediates 20E signalling independent of the E75-HR3-FTZ-F1 transcriptional cascade. Furthermore, silencing of both LdE74 isoforms caused failure of ecdysis. Most of the LdE74 RNAi beetles remained as prepupae. The LdE74 RNAi prepupae exhibited adult character-like forms underneath after removal of the apolysed larval cuticle. Their appendages such as antennae, legs and wings were shorter than those of control larvae. Only a few LdE74 RNAi larvae finally became deformed pupae, with shortened antennae and legs. Therefore, LdE74 is required for larval-pupal metamorphosis and appendage growth in L. decemlineata.

Chemical composition, true nutrient digestibility, and true metabolizable energy of novel pet food protein sources using the precision-fed cecectomized rooster assay

A wide variety of animal protein-based ingredients is commonly used in the pet food products. The raw ingredients and processing procedures used may greatly affect protein quality. Testing the quality of alternative protein sources is necessary and contributes to the sustainability of pet foods. The objective of this study was to test the chemical composition of 8 protein sources intended for use in dog and cat foods (calamari meal, pork peptone, alligator meal, lamb meal, venison meal, chicken meal, and 2 duck meals), and evaluate their true nutrient digestibility and nitrogen-corrected true ME (TMEn) using the precision-fed cecectomized rooster assay. Calamari meal and pork peptone had lower ash (4.4 and 3.6% of DM, respectively) but greater CP (88.1 and 80.5% of DM, respectively) and either greater or similar GE (5.6 and 5.3 kcal/g of DM, respectively) compared with alligator, lamb, venison, chicken, and duck meals (11.8 to 24.5% ash, 58.7 to 65.9% CP, and 4.6 to 5.3 kcal GE/g). Acid-hydrolyzed fat (AHF) was lower in calamari meal (8.7% of DM) compared with the other proteins tested (15.5-22.1% of DM). True nutrient digestibility was variable among the protein sources (52 to 79% of DM, 60 to 83% of OM, 78 to 92% of AHF, and 70 to 89% of GE) with pork peptone having the highest DM, AHF, and GE digestibility and calamari meal having the highest OM digestibility. True indispensable AA digestibility was highest for calamari meal, with all AA having a digestibility greater than 90%. Except for histidine, all indispensable AA had a digestibility over 85% for pork peptone. In contrast, true indispensable AA digestibility was lowest for lamb meal, with histidine having digestibility less than 70% and the other entire indispensable AA having digestibility between 72 and 88%. The TMEn of calamari meal (4.82 kcal/g DM and 86.9% of GE) was greater ( < 0.05) than the other protein sources. The lamb meal had the lowest TMEn value (3.12 kcal/g DM and 66.9% of GE), with others being intermediate (3.46-4.09 kcal/g DM and 71.2-77.9% of GE). This study demonstrates the considerable variability that exists not only in the chemical composition but also in the true nutrient digestibility among protein sources intended for use in dog and cat foods and justifies further in vivo testing of novel protein sources.

COMPANION ANIMALS SYMPOSIUM: Future aspects and perceptions of companion animal nutrition and sustainability

Companion animals play an important role in our lives and are now considered to be and treated as family members in a majority of households in the United States. Because of the high number of pets that now exist, an increasingly stronger pet-human bond, and the importance placed on health and longevity, the pet food industry has realized steady growth over the last few decades. Despite past successes and opportunities that exist in the future, there are also challenges that must be considered. This review will present a brief overview of the current pet food industry and address some of the key issues moving forward. In regards to companion animal research, recent advances and future needs in the areas of canine and feline metabolism, aging, clinical disease, and the gut microbiome using molecular and high-throughput assays; chemical, in vitro, and in vivo testing of feed ingredients; and innovative pet food processing methods is discussed. Training the future workforce for the pet food industry is also of great importance. Recent trends on student demographics and their species and careers of interest, changing animal science department curricula, and technology's impact on instruction are provided. Finally, the sustainability of the pet food industry is discussed. Focus was primarily placed on the disconnect that exists between opinions and trends of consumers and the nutrient recommendations for dogs and cats, the desire for increasing use of animal-based and human-grade products, the overfeeding of pets and the pet obesity crisis, and the issues that involve the evaluation of primary vs. secondary products in terms of sustainability. Moving forward, the pet food industry will need to anticipate and address challenges that arise, especially those pertaining to consumer expectations, the regulatory environment, and sustainability. Given the already strong and increasingly dynamic market for pet foods and supplies, an academic environment primed to supply a skilled workforce, and continued industry support for basic and applied research initiatives, the future of the pet food industry looks very bright.

Effects of feeding frequency and dietary water content on voluntary physical activity in healthy adult cats

Low physical activity has been identified as a major risk factor for the development of feline obesity and diabetes. This study aimed to evaluate the effects of increased meal frequency and dietary water content on voluntary physical activity in cats fed to maintain BW. Ten adult lean neutered male cats were used in 2 tests, both crossover studies composed of a 14-d adaptation period, followed by a 7-d measurement of physical activity from d 15 to d 22 using Actical activity collars. Cats were group housed for most of the day, except for times when they were individually housed in cages to access their diet under a 16:8 h light:dark cycle. In Exp. 1, the difference in voluntary physical activity among cats fed 1, 2, 4, or a random number of meals per day were tested in a 4 × 4 Latin square design in 4 individual rooms. In Exp. 2, the effect of increasing dietary water content on voluntary physical activity was tested in a crossover design including a 5-d phase for fecal and urine collection from d 22 to 27. Cats were randomly assigned to 2 rooms and fed a dry commercial diet with or without added water (70% hydrated) twice daily. Activity levels were expressed as "activity counts" per epoch (15 s). In Exp. 1, average daily activity level for 1-meal-fed cats was lower than 4-meal-fed (P = 0.004) and random-meal-fed (P = 0.02) cats, especially during the light period. The activity level of cats during the dark period was greater in 1-meal-fed cats compared with cats fed 2 meals (P = 0.008) or 4 meals (P = 0.007) daily. Two-hour food anticipatory activity (FAA) before scheduled meal times for 1-meal-fed cats was lower (P < 0.001) than for the multiple-meal-fed cats. In Exp. 2, average daily activity level of cats fed the 70% hydrated diet tended to be higher (P = 0.06) than cats fed the dry diet, especially during the dark period (P = 0.007). Two-hour FAA before the afternoon meal for cats fed the 70% hydrated diet was lower (P < 0.05) than for cats fed the dry diet. Cats fed the 70% hydrated diet had greater daily fecal (P = 0.008) and urinary (P = 0.001) outputs and lower (P < 0.001) urinary specific gravity compared to cats fed the dry diet. In conclusion, increased feeding frequency and dietary water content, without changing energy intake or dietary macronutrient composition, appear to promote physical activity, which may aid in weight management in cats.

Downregulation of Kv4.2 channels mediated by NR2B-containing NMDA receptors in cultured hippocampal neurons

Somatodendritic Kv4.2 channels mediate transient A-type potassium currents (I(A)), and play critical roles in controlling neuronal excitability and modulating synaptic plasticity. Our studies have shown an NMDA receptor-dependent downregulation of Kv4.2 and I(A). NMDA receptors are heteromeric complexes of NR1 combined with NR2A-NR2D, mainly NR2A and NR2B. Here, we investigate NR2B receptor-mediated modulation of Kv4.2 and I(A) in cultured hippocampal neurons. Application of glutamate caused a reduction in total Kv4.2 protein levels and Kv4.2 clusters, and produced a hyperpolarized shift in the inactivation curve of I(A). The effects of glutamate on Kv4.2 and I(A) were inhibited by pretreatment of NR2B-selective antagonists. NR2B-containing NMDA receptors are believed to be located predominantly extrasynaptically. Like application of glutamate, selective activation of extrasynaptic NMDA receptors caused a reduction in total Kv4.2 protein levels and Kv4.2 clusters, which was also blocked by NR2B-selective antagonists. In contrast, specific stimulation of synaptic NMDA receptors had no effect on Kv4.2. In addition, the influx of Ca(2+) was essential for extrasynaptic modulation of Kv4.2. Calpain inhibitors prevented the reduction of total Kv4.2 protein levels following activation of extrasynaptic NMDA receptors. These results demonstrate that the glutamate-induced downregulation of Kv4.2 and I(A) is mediated by NR2B-containing NMDA receptors and is linked to proteolysis by calpain, which might contribute to the development of neuronal hyperexcitability and neurodegenerative diseases.

The genetic basic and fine-mapping of a stable quantitative-trait loci for aluminium tolerance in rice

Aluminium (Al) toxicity is a primary cause of low rice productivity in acid soils. We have mapped a number of quantitative-trait loci (QTL) controlling Al tolerance in a recombinant inbred line population derived from a cross between the tolerant japonica cultivar Asominori and the sensitive indica cultivar IR24. Tolerance was assessed on the basis of relative root elongation. QTL were detected on chromosomes 1, 9, and 11, with the percentages of phenotypic variance explained ranging from 13.5 to 17.7%. Alleles from Asominori at all three QTL were associated with increased Al tolerance. qRRE-9 is expressed both in the genetic background of IR24 and in an Asominori/IR24-mixed background. qRRE-9 was reduced to the single recessive Mendelian factor Alt-9. High-resolution genetic and physical maps were constructed for Alt-9 in a BC(3)F(2) population of 1,043 individuals. Alt-9 maps between RM24702 and ID47-2 on chromosome 9, and co-segregates with RM5765.

Increase of delayed rectifier potassium currents in large aspiny neurons in the neostriatum following transient forebrain ischemia

Large aspiny (LA) neurons in the neostriatum are resistant to cerebral ischemia whereas spiny neurons are highly vulnerable to the same insult. Excitotoxicity has been implicated as the major cause of neuronal damage after ischemia. Voltage-dependent potassium currents play important roles in controlling neuronal excitability and therefore influence the ischemic outcome. To reveal the ionic mechanisms underlying the ischemia-resistance, the delayed rectifier potassium currents (Ik) in LA neurons were studied before and at different intervals after transient forebrain ischemia using brain slices and acute dissociation preparations. The current density of Ik increased significantly 24 h after ischemia and returned to control levels 72 h following reperfusion. Among currents contributing to Ik, the margatoxin-sensitive currents increased 24 h after ischemia while the KCNQ/M current remained unchanged after ischemia. Activation of protein kinase A (PKA) down-regulated Ik in both control and ischemic LA neurons, whereas inhibition of PKA only up-regulated Ik and margatoxin-sensitive currents 72 h after ischemia, indicating an active PKA regulation on Ik at this time. Protein tyrosine kinases had a tonic inhibition on Ik to a similar extent before and after ischemia. Compared with that of control neurons, the spike width was significantly shortened 24 h after ischemia due to facilitated repolarization, which could be reversed by blocking margatoxin-sensitive currents. The increase of Ik in LA neurons might be one of the protective mechanisms against ischemic insult.

Passively Q-Switched Yb:YAG Laser with Cr(4+):YAG as the Saturable Absorber

By using a continuous-wave Ti:sapphire laser as a pumping source, we demonstrated a passively Q-switched Yb:YAG laser at room temperature with Cr(4+):YAG as the saturable absorber. We achieved an average output power of as much as 55 mW at 1.03 mum with a pulse width (FWHM) as short as 350 ns. The initial transmission of the Cr(4+):YAG has an effect on the pulse duration (FWHM) and the repetition rate of the Yb:YAG passively Q-switched laser. The Yb:YAG crystal can be a most promising passively Q-switched laser crystal for compact, efficient, solid-state lasers.

Laser performance of highly neodymium-doped yttrium aluminum garnet crystals

The laser performance of highly neodymium-doped yttrium aluminum garnet (YAG) crystals is reported. In cw laser-diode pumping, a slope efficiency of 54% was achieved for a 2-at. %-doped sample, which was comparable with the slope efficiency of 55% of YVO(4) . The crystal also exhibited a slope efficiency of 64% under pulsed Ti:sapphire pumping. Such a high efficiency suggests a total cavity loss of ~1% , which is as low as that of commercially available 1-at. % YAG crystal. The excellent performance of the neodymium-doped YAG crystals indicates their high optical quality.

Localization of neurotransmitters and calcium binding proteins to neurons of salamander and mudpuppy retinas

We wished to identify the different types of retinal neurons on the basis of their content of neuroactive substances in both larval tiger salamander and mudpuppy retinas, favored species for electrophysiological investigation. Sections and wholemounts of retinas were labeled by immunocytochemical methods to demonstrate three calcium binding protein species and the common neurotransmitters, glycine, GABA and acetylcholine. Double immunostained sections and single labeled wholemount retinas were examined by confocal microscopy. Immunostaining patterns appeared to be the same in salamander and mudpuppy. Double and single cones, horizontal cells, some amacrine cells and ganglion cells were strongly calbindin-immunoreactive (IR). Calbindin-IR horizontal cells colocalized GABA. Many bipolar cells, horizontal cells, some amacrine cells and ganglion cells were strongly calretinin-IR. One type of horizontal cell and an infrequently occurring amacrine cell were parvalbumin-IR. Acetylcholine as visualized by ChAT-immunoreactivity was seen in a mirror-symmetric pair of amacrine cells that colocalized GABA and glycine. Glycine and GABA colocalized with calretinin, calbindin and occasionally with parvalbumin in amacrine cells.

[Histochemical observation of changes of neurons and axons in injured brainstem]

Brainstem of rats were stabbed with a needle and pathological changes of neurons and axons in brainstem were observed at different time after injury with Nissl's body staining, silver staining and modified trichrome staining. It was found that, by silver staining, the axons showed irregular swelling and disconnection at 1-3 h, marked swelling of the severe end at 6 h, retraction ball at 15 h and remarkable retraction ball at 24 h. By modified trichrome staining, the space between myelin sheaths and axons was widened at 3-6 h, and tortuous myelin sheaths adhered incompletely on axons, or even peeled off at 15 h to 24 h. Perinuclear lysis of Nissl's bodies at 24 h after injury could be seen by Nissl body staining. The results indicated that, the pathological changes in injured brainstem could be observed with histochemical staining, which might be used for timing brainstem injuries.

Biological characterization of uncleavable plasma membrane-anchored human macrophage colony-stimulating factor

The cell-surface form of human macrophage colony-stimulating factor (CSF-1(256), M-CSFalpha) is a plasma membrane-anchored transmembrane protein from which the soluble CSF-1 is released by ectodomain proteolytic cleavage. We have previously generated two forms of cell surface CSF-1 which failed to undergo the cleavage by deleting residues 161-165 or residues 159-165 in the extracellular juxtamembrane region (1). To determine the biologic significance of the ectodomain cleavage, we compared the biosynthesis and biologic activities of uncleavable mutant CSF-1 forms with those of the cleavable wild-type (WT) CSF-1. We found that the uncleavable CSF-1 forms were able to accumulate on cell surface at about threefold higher level than the cleavable WT CSF-1 did. We further demonstrated that the uncleavable plasma membrane-anchored forms of CSF-1 were biologically active in mediating the proliferation of CSF-1-dependent cells as well as the intercellular adhesion between CSF-1 receptor-bearing cells and CSF-1 expressing cells. Furthermore, the adhesive activity of uncleavable CSF-1 forms was about twofold stronger than that of WT CSF-1, which indicated that the ectodomain cleavage system plays an important role in regulating the biologic activities of membrane-anchored CSF-1.

Laser-diode-pumped Cr(4)+, Nd(3)+:YAG with self-Q-switched laser output of 1.4 W

By use of a laser diode as a pump source, a self-Q-switched laser from a Cr, Nd:YAG crystal is demonstrated. The output Q-switched traces are very stable, the threshold pump power is 3.5 W, the pulse duration is 50 ns, and the slope efficiency is as high as 20%. In addition, the pulse width remains constant while the pulse repetition rate varies with pump power.

[Spectroscopy performances of Yb3+ doped YAG crystal]

The absorption and emission properties of Yb:YAG with different Yb3+ doped concentration have been studied systematically. The emission cross section has been evaluated using the absorption cross section and principle of reciprocity, which was consistent with previous reports. The absorption spectra of Yb2+ and color center were observed in as-grown Yb:YAG boules, which are removed by annealing the boules in oxygen at 1,300 degrees C for 24 h. The photon excited and X-ray excited optical luminescence of Yb:YAG were first discussed. The results indicated that Yb:YAG crystal was favourable for high-power diode-pumping.

[Effect of human plasma HDL on the HDL receptors of plasma membranes of cholesterol-fed rabbit]

Atherosclerosis(As) rabbit model was developed by high-cholesterol feeding for 12 weeks. The rabbits were injected intravenously with human plasma HDL preparation per week, and then the effects of HDL on the lipids contents of serum, liver and bile nd the activity of HDL receptors on liver plasma membranes of cholesterol-fed rabbit were investigated. The results showed that HDL preparation had no effect on decreasing the lipids contents of serum, but it could low down the lipid depositions in liver, and promote the excretion of lipids from bile. The value of Bmax of HDL receptor showed decreasing trendy and the value of Kd showed increasing trendy in cholesterol-fed rabbits. In HDL-treated rabbits, the value of Bmax increased significantly as compared with that of normal group(P < 0.05), but the value of Kd showed no difference. The results suggested that human plasma HDL could enhance the activity of HDL receptors on the liver plasma membranes of cholesterol-fed rabbit.

Solution structure of the major alpha-amylase inhibitor of the crop plant amaranth

alpha-Amylase inhibitor (AAI), a 32-residue miniprotein from the Mexican crop plant amaranth (Amaranthus hypochondriacus), is the smallest known alpha-amylase inhibitor and is specific for insect alpha-amylases (Chagolla-Lopez, A., Blanco-Labra, A., Patthy, A., Sanchez, R., and Pongor, S. (1994) J. Biol. Chem. 269, 23675-23680). Its disulfide topology was confirmed by Edman degradation, and its three-dimensional solution structure was determined by two-dimensional 1H NMR spectroscopy at 500 MHz. Structural constraints (consisting of 348 nuclear Overhauser effect interproton distances, 8 backbone dihedral constraints, and 9 disulfide distance constraints) were used as an input to the X-PLOR program for simulated annealing and energy minimization calculations. The final set of 10 structures had a mean pairwise root mean square deviation of 0.32 A for the backbone atoms and 1.04 A for all heavy atoms. The structure of AAI consists of a short triple-stranded beta-sheet stabilized by three disulfide bonds, forming a typical knottin or inhibitor cystine knot fold found in miniproteins, which binds various macromolecular ligands. When the first intercystine segment of AAI (sequence IPKWNR) was inserted into a homologous position of the spider toxin Huwentoxin I, the resulting chimera showed a significant inhibitory activity, suggesting that this segment takes part in enzyme binding.

Multiple factors determine the selection of the ectodomain cleavage site of human cell surface macrophage colony-stimulating factor

Human cell surface macrophage colony-stimulating factor (CSF-1256, M-CSF alpha) is converted to a soluble growth factor by a regulated proteolytic cleavage process at amino acid residues 157-159. We have previously shown that multiple factors specified by the juxtamembrane region determine the cleavage efficiency [Deng, P., Rettenmier, C. W., and Pattengale, P. K. (1996) J. Biol. Chem. 271, 16338-16343]. In the present paper, we studied the effect of various deletion, insertion, and substitution mutations at or near the cleavage site on both the number and size of cleaved CSF-1(256) products to identify the mechanisms by which the cleavage sites are selected. Deletion of regions 161-162 or 163-165, C-terminal to the cleavage site, as well as deletion of region 150-156, N-terminal to the cleavage site, each yielded a single cleavage product that was smaller than that derived from the wild type (WT). In these experiments cleavage apparently occurred at a specific distance from the transmembrane domain. Insertion of three additional residues between the normal cleavage site and the transmembrane domain yielded one major product that was the same size as the processed form of WT CSF-1(256). In this case the selection of the cleavage site was apparently determined by the amino acid sequence of the juxtamembrane region rather than by the distance from the transmembrane domain. Other amino acid substitutions at the cleavage site caused changes in cleavage site selection, providing additional evidence for the role of amino acid sequence in cleavage site selection. Finally, a comparison of cleavage site selection in the presence and absence of tunicamycin treatment showed that N-glycosylation of certain mutant forms of CSF-1(256) sterically interfered with protease accessibility, which in turn had an effect on the selection of the site used for cleavage. Taken together, these results indicate that cleavage site selection is determined by the amino acid sequence of the juxtamembrane region, the distance of the site from the transmembrane domain, and steric accessibility of the protease.

Passively Q-switched Nd:YVO(4) laser with a Cr(4+):YAG crystal saturable absorber

We demonstrate, for the first time as far as we know, a passively Q-switched operation of a Nd:YVO(4) laser in which a Cr(4+):YAG crystal and a laser-diode bar are used as the saturable absorber and the pump source, respectively. Stable laser pulses as short as 28 ns with 20-muJ energy can be generated with this laser, which has the advantages of simplicity, high efficiency, and good long-term stability.

[The carcinogenesis of human cytomegalovirus to mouse cervix]

We plugged the gelfoam impregnated with virus stock solution into mouse cervix with ophthalmic forceps. Mice of Kun-Ming strain were infected with UV-inactivated HCMV (human cytomegalovirus). After 31 weeks, cervical carcinomas were induced in 15% of the infected mice. In another group, infected with UV-inactivated HCMV adding croton oil, the carcinogenesis was 18.8%, but incontrol group, it was 0%. HCMV IE (immediate early) antigen in 12 cancer tissues of UV-inactivated HCMV treated group were all positive, and HCMV IE antibody geometrical average titre in mouse serum of the same group was 1:167.2, but the same two parameters in control group were both negative. The ANAE positive rate of lymphocytes in mouse peripheral blood of UV-inactivated HCMV treated group was 38.9 +/- 6.8%, and of control group was 67.8 +/- 8.0%.

Hemostatic and fibrinolytic response to desmopressin in uremic patients

Desmopressin (DDAVP) 0.3 micrograms/kg was infused in 20 uremic patients with prolong bleeding time. Prior to infusion, the uremic patients had a reduced level of tissue plasminogen activator (t-PA), normal levels of von Willebrand factor antigen (vWF:Ag) and ristocetin cofactor activity (vWF:RCo) and elevated level of factor VIII coagulant activity (FVIII:C). Patients with lower hematocrit or t-PA levels tended to have a longer bleeding time. One hour after DDAVP infusion, the bleeding time was shortened significantly. This improvement was significant in all patient groups irrespective of the high or low initial levels of factor VIII complex components. Plasma levels of FVIII:C, vWF:Ag, vWF:RCo and t-PA all increased significantly. The magnitude of increase in these factors, however, was not significantly correlated with the extent of bleeding time shortening. The multiple regression model for predicting the extent of bleeding time shortening suggested only two variables, viz initial bleeding time and posttreatment FVIII:C activity to be of significance. The present results indicate that the hemostatic response to DDAVP is uniform in uremic patients, regardless of whether the initial activities of factor VIII complex components are high or low. Posttreatment FVIII:C activity appears to play a significant role in the hemostatic action of DDAVP. Furthermore, a depressed fibrinolytic activity was generally observed to concur with the hemostatic defect in uremic patients.

The role of individual cysteine residues in the processing, structure, and function of human macrophage colony-stimulating factor

The shortest form of human macrophage colony-stimulating factor (M-CSF alpha, CSF-1(256) is expressed on the cell surface as a homodimeric type I transmembrane glycoprotein. The seven cysteine residues in CSF-1(256) form three intrachain disulfide bonds (Cys7-Cys90, Cys48-Cys139, and Cys 102-Cys146), and one interchain disulfide bond (Cys31-Cys31). To examine the role of the seven cysteine residues in CSF-1(256), we replaced each half-cystine by a serine using site-directed mutagenesis, and stably expressed the mutated genes in mouse NIH 3T3 cells. We showed that each of the seven cysteines of CSF-1(256) is essential for its biological activity. Our data further show that substitution of Cys48 or Cys139 totally blocked dimer formation and cell surface expression of CSF-1(256), and that substitution of Cys102 and Cys146 severely impaired CSF-1 dimer formation and cell surface expression. In contrast, substitution of Cys7 or Cys90 affected CSF-1 dimer formation to a lesser degree but did not significantly affect cell surface expression of CSF-1. Furthermore, disruption of the interchain disulfide bond led to efficient cell surface expression of monomeric CSF-1. All of the cell surface expressed mutant CSF-1 proteins, either dimeric or monomeric, still underwent efficient ectodomain cleavage. The electrophoretic mobilities of the cleaved dimeric ectodomains of these mutant CSF-1 proteins on SDS-PAGE exhibited distinctly different patterns as compared with the wild type. Substitution of either Cys7 or Cys90 produced the same shift, while substitution of either Cys102 or Cys146 resulted in a shift distinct from that caused by substitution of Cys7 or Cys90. These data suggest that replacement of either of a pair of intrachain half-cystine residues results in similar conformational changes, and may provide a novel method for mapping intrachain disulfide bonds in dimeric proteins.

Structural requirements for the ectodomain cleavage of human cell surface macrophage colony-stimulating factor

One form of human macrophage colony-stimulating factor (CSF-1(256), M-CSFalpha) is a member of a restricted set of cell surface transmembrane proteins, which is selected to undergo proteolytic ectodomain cleavage. To determine the substrate requirements for this cleavage, we have constructed a series of mutations in the cytoplasmic tail, transmembrane domain, and juxtamembrane region of CSF-1(256) and stably expressed the mutated genes in NIH 3T3 cells. Our results demonstrate that membrane association of the CSF-1 precursor is required for cleavage of its growth factor ectodomain and furthermore that the juxtamembrane region Pro161-Gln162-Leu163-Gln164-Glu165 (PQLQE) (residues 161-165 of the ectodomain) is an essential determinant of cell surface CSF-1(256) cleavage and that the cleavage site is partially sequence-specific. Furthermore, a mechanism of steric hindrance, which likely involves interference with protease accessibility, is postulated to explain the observed decreases in the cleavage efficiency in certain CSF-1 mutants. Finally, our results strongly suggest that the CSF-1 ectodomain is cleaved at or very near the cell surface by a membrane-associated proteolytic system.

A preliminary study of skin electrical injury with computerized image analysis

This paper reports the application of computerized image analysis to a quantitative study of skin electrical injury in order to provide an objective and quantitative standard for identifying the electrical mark. The differences between antemortem and postmortem electrical injuries were also studied. In normal and electrically-injured human skin, the long/short axes ratio of nuclei were measured. The mean of epithelial basal cells was 1.4344 and 5.9325, respectively, the mean of hair follicle cells was 1.6193 and 4.5988, respectively, and the mean of capillary endothelial cells was 4.0229 and 4.3593, respectively. In rat specimens, the long/short axes ratio of nuclei of normal skin, at 15 and 5 min ante-mortem and at 5 min postmortem injury, the mean epithelial basal cells was 1.4124, 4.5417, 5.2282 and 5.0447, respectively. The mean of hair follicle cells was 1.4140, 4.4863, 4.1146 and 4.4522, respectively, while the mean of capillary endothelial cells was 2.8398, 3.7514, 3.6159 and 3.6977, respectively. The results indicate that the differences between electrical injuries and normal skin with respect to the ratios of long/short axes of the epithelial basal cell nuclei and hair follicle cell nuclei are of remarkable significance. On the other hand, no significant difference could be found between antemortem and postmortem injuries, nor between electrical injury and normal skin, concerning the long/short axes ratios of capillary endothelial cell nuclei. This result provides a preliminary objective standard for the changes of electrical skin injury.

Operation of a Ti:sapphire laser pumped by a 499-nm green laser

We report, for the first time, to our knowledge, the operation of a tunable Ti:sapphire laser pumped by a third-order Raman XeCl-H(2) laser system at 499 nm with a 60-ns pulse duration. The slope efficiency is 59% for this laser, producing pulses of 20-ns duration. The highest conversion-energy efficiency obtained is 41%, with an output energy of 1.2 mJ. The tuning range for a single set of cavity mirrors is 680-834 nm and is limited mainly by the mirror reflectivity. This study shows that a combined laser system based on a XeCl excimer laser can offer wavelength diversity.