Effect of membrane stabilizers on semen quality and sperm membrane protein expression during cryopreservation of goat semen.

BACKGROUND: Semen cryopreservation is a complex process during which there is alteration in the expression of sperm and seminal plasma proteins, molecular weight of protein or loss of membrane proteins during the process. In order to compensate for these changes, different membrane stabilizers are used in freezing semen extenders. However, there is scarcity of such studies during cryopreservation of goat semen. OBJECTIVE: To investigate the effect of membrane stabilizers on sperm membrane protein expression during cryopreservation of goat semen. MATERIALS AND METHODS: A total of 36 semen ejaculates from nine Assam Hill Goat bucks aged 2 to 2.5 years was collected by artificial vagina method. Three membrane stabilizers, each at two different concentrations viz. 50 and 80 mM sucrose, 50 and 100 mM trehalose, and 100 and 150 ng per mL IGF-1 (insulin-like growth factor 1 protein) were added to Tris-citric acid fructose egg yolk glycerol (TCFEYG) extender and semen samples were cryopreserved. The sperm membrane protein profile was studied in fresh and cryopreserved semen by SDS-PAGE. RESULTS: SDS- PAGE of sperm membrane extract of fresh semen revealed the presence of 24 protein bands with molecular weights ranging from 10 kDa to 240 kDa. Samples supplemented with 50 mM sucrose and 80 mM sucrose revealed 21 protein bands with molecular weights ranging from 10 kDa to 240 kDa. All the 21 protein bands were same as those observed in the sperm membrane of fresh spermatozoa, except that the 23 kDa, 29 kDa and 42 kDa bands were absent in frozen semen. Similarly, frozen semen extended with 50 mM trehalose and 100 mM trehalose revealed 22 protein bands with molecular weights ranging from 10 kDa to 240 kDa, but lacking the 29 kDa and 42 kDa bands. Proteins with molecular weights of 29 kDa, 130 kDa and 240 kDa were absent in frozen semen supplemented with 100 ng per mL IGF-1 and 150 ng per mL IGF-1. CONCLUSION: The present study revealed that supplementation of tris basic extender with trehalose at 100 mM and or IGF-1 at 100 ng/mL or 150 ng per mL improves the post-thaw semen characteristics and protects certain fertility related sperm membrane proteins. Doi.org/10.54680/fr23510110612.

High spatial-density, cladding-pumped 6-mode 7-core fiber amplifier for C-band operation.

We present a C-band 6-mode 7-core fiber amplifier in an all-fiberized cladding-pumped configuration for space division multiplexed transmission supporting a record 42 spatial channels. With optimized fiber components (e.g. passively cooled pump laser diode, pump coupler, pump stripper), high power multimode pump light is coupled to the active fiber without any noticeable thermal degradation and an average gain of 18 dB and noise figure of 5.4 dB are obtained with an average differential modal gain of 3.4 dB.

Study on the temperature dependent characteristics of O-band bismuth-doped fiber amplifier.

We report the temperature dependent performance of an O-band bismuth (Bi)-doped fiber amplifier (BDFA) in the temperature range from -60 to +80°C. At room temperature, maximum gains of 27 and 40 dB with noise figures (NFs) of 4.3 and 4.8 dB are measured for -23 dBm signal power in the single and double pass BDFA, respectively. An increment in gain and reduction in NF is observed as the ambient temperature of the BDFA is reduced. In the double pass BDFA, the temperature dependent gain coefficient from -60 to +80°C is found to be around -0.02 and -0.03 dB/°C across the wavelength band of 1300-1360 nm for -10 and -23 dBm signal powers, respectively. We also study the gain and NF characteristics with pump power and signal power at different temperatures, and a maximum gain of 45 dB is obtained at -60°C for -30 dBm signal power.

40 dB gain all fiber bismuth-doped amplifier operating in the O-band.

In this Letter, we investigate and compare the gain and noise figure characteristics of bismuth (Bi)-doped fiber amplifiers configured in both single and double signal pass implementations. A maximum gain of 25 dB and a noise figure of 4 dB is measured at 1360 nm in the single pass configuration for -23 dBm input signal power, whereas in the double pass configuration the gain of the amplifier is improved significantly by 14 dB allowing us to achieve a gain of 39 dB with a noise figure of 5 dB. To the best of our knowledge, this is the highest gain reported to date using Bi-doped fiber as a gain medium. Furthermore, we also study the gain and noise figure dependency on pump power, signal power, and pump wavelength for the double pass amplifier configuration. We observed similar gain and noise figure performance in the double pass configuration to that of the single pass configuration but with the benefit of less pump power and a shorter length of the Bi-doped fiber.

Bismuth-doped all-fiber mode-locked laser operating at 1340 nm.

We demonstrate a 1340 nm mode-locked Bismuth (Bi)-doped fiber laser without any saturable absorber. The effect of pump power on pulse width is studied, and a variation from 1.5 to 3 ns is reported. The output of the mode-locked Bi-doped fiber laser is further amplified using a master oscillator power amplifier configuration, and a peak power of 1.15 W is achieved. Soliton bunching is observed, and a true pulse width of 1.2 ps is reported from the measured autocorrelation trace. Stable operation of the mode-locked laser is verified from the radio-frequency spectrum with a fundamental repetition rate of 6.3 MHz, and SNR of 65 dB.

Bi-doped fiber amplifier with a flat gain of 25 dB operating in the wavelength band 1320-1360 nm.

Bismuth (Bi)-doped phosphosilicate fibers have been fabricated by the modified chemical vapor deposition (MCVD)-solution doping technique under different process conditions. The influence of fabrication conditions on unsaturable loss in fibers has been investigated. Pump wavelength dependent Bi gain has been studied to obtain a flat gain over a wide bandwidth. A diode pumped all-fiber Bi-doped amplifier with a flat gain of 25±1 dB from 1320-1360 nm (40 nm) has been demonstrated for -10 dBm of input signal power with a noise figure (NF) ranging from 4-6 dB. Moreover, a small signal gain of 29 dB and a NF of 4.5 dB at 1340 nm has been achieved for an input signal power of -30 dBm.

Highly efficient Yb-free Er-La-Al doped ultra-low NA large mode area single-trench fiber laser.

We demonstrate a 60µm core diameter Yb free Er-La-Al doped single-trench fiber having a 0.038 ultra-low-NA, fabricated using conventional MCVD process in conjunction with solution doping technique. Numerical simulations predict an effective single mode operation with effective area varying from 1,820µm(2) to 1,960µm(2) (taking bend-induced modal distortion into account) for different thicknesses of trenches and resonant rings at a constant bend radius of 25cm. Moreover, all solid structure favors easy cleaving and splicing. Experimental measurements demonstrate a robust effective single mode operation. Furthermore, with a 4%-4% laser cavity, this fiber shows a record efficiency of 46% with respect to the absorbed pump power.

Large mode area multi-trench fiber for UV and visible transmission.

We experimentally demonstrate all-solid 10 and 20 µm core diameter multi-trench fibers for UV and visible wavelengths. Measurements ensure an effective single-mode operation over a wide range of bend radii, which is suitable for applications such as beam delivery. Both fibers were fabricated by the conventional modified chemical vapor deposition process, which is suitable for mass production. Moreover, all-solid fiber design ensures easy cleaving and splicing.

1120 nm diode-pumped Bi-doped fiber amplifier.

Bismuth-doped aluminosilicate fiber has been fabricated by the MCVD-solution doping method and characterized for its unsaturable loss and gain. The amplifier performance has been compared for a novel pumping wavelength of 1120 nm with the conventional pumping wavelength region of 1047 nm. Unsaturable loss was 65% and 35% at 1047 and 1120 nm, pump wavelengths, respectively. A maximum gain of about 8 dB at 1180 nm for a fiber length of 100 m was observed with 1120 nm pumping. Gain enhancement of 70% was achieved with the 1120 nm pump as compared to the 1047 nm pump. A further 3.5 dB gain was obtained on simultaneous pumping at 1047 and 1120 nm.

Prevalence of smear-positive tuberculosis in persons aged ≥ 15 years in Bangladesh: results from a national survey, 2007-2009.

The aim of this study was to determine the nationwide prevalence of smear-positive tuberculosis (TB) in Bangladesh. A multi-stage cluster survey of a random sample of persons aged ≥ 15 years was included in 40 clusters (20 urban, 20 rural). Two sputum samples were collected from study participants and tested initially by fluorescence microscopy and confirmed by the Ziehl-Neelsen method. The crude and adjusted prevalence rates and 95% confidence intervals (CIs) were calculated using standard methods. A total of 33 new smear-positive TB cases were detected among 52 098 individuals who participated in the study. The average participation rate was over 80%. The overall crude prevalence of new smear-positive TB in persons aged ≥ 15 years was estimated as 63.3/100 000 (95% CI 43.6-88.9) and the adjusted prevalence was 79.4/100 000 (95% CI 47.1-133.8). TB prevalence was higher in males (n = 24) and in rural areas (n = 20). The prevalence was highest in the 55-64 years age group (201/100 000) and lowest in 15-24 years age group (43.0/100 000). The prevalence was higher in persons with no education (138.6/100 000, 95% CI 78.4-245.0). The overall prevalence of smear-positive TB was significantly lower than the prevalence estimate of the previous nationwide survey in Bangladesh in 1987-1988 (870/100 000).

Gnathostomiasis of the anterior chamber.

Ocular involvement with Gnathostoma spinigerum occurs years after the initial infection that is acquired by ingestion of poorly cooked, pickled seafood or water contaminated with third stage larvae. Here we report a case of gnathostomiasis of the left eye of a 32-year-old lady hailing from Meghalaya, India. Her vision had deteriorated to hand movement. Slit lamp examination revealed a live, actively motile worm in the anterior chamber, which was extracted by supra temporal limbal incision and visual acuity was restored.

Loa loa in the anterior chamber of the eye: a case report.

An unusual case of loiasis from Assam is reported here. Loa loa is a subcutaneous filarial parasite of man and is transmitted to humans by chrysops flies. The patient presented with foreign body sensation and visual disturbances of the right eye. Examination revealed a white coiled structure in the cornea. Routine blood and other investigations were within normal limits. A live adult worm was extracted and identity was confirmed by microscopy to be Loa loa. Patient was treated with diethylcarbamazine and steroid. We found this case interesting as the worm was present in the anterior chamber--an unusual site and there were no other positive findings besides the lone worm.

Wild edible mushrooms of meghalaya.

Different flesh mushrooms grow widely in Meghalaya. Altogether fie edible species were collected and identified which were found abundantly in forest and are known to be consumed by local people for time immemorial, The species identified are lentinus edodes (Berk) Sing., Boletus edulis Bull ex Fr., Clavaria cinerea (Fr.) Schroet, Clavaria aurea (F) Quet and cantharellus floccosus Juss.

A gene for hereditary pancreatitis maps to chromosome 7q35.

BACKGROUND & AIMS: Hereditary pancreatitis (HP) is an autosomal-dominant disorder with incomplete penetrance characterized by recurrent bouts of severe epigastric pain with onset usually at 5-10 years of age. A genetic linkage study was designed to identify the HP gene. METHODS: A 500-member pedigree was constructed from a U.S. kindred centered in eastern Kentucky and western Virginia. A genome-wide search strategy was employed using a 36-member subset of this family to determine the genetic locus for HP. Testing for linkage to microsatellite loci was performed at 20-cM intervals. RESULTS: Linkage was established between the HP phenotype and chromosome 7q in this subset of the family. Modeled as an autosomal dominant disorder with 80% penetrance, a maximal multipoint logarithm of the odds score of 4.3 was obtained using a four-point analysis consisting of markers D7S684, D7S661, D7S505, and the HP locus. Two microsatellite markers, D7S661 and D7S505, that correspond to the 7q35 region of chromosome 7 spanning a 6-cM region did not evidence obligate recombinations with HP. The centromeric and telomeric limits are defined by recombinations at D7S684 and D7S483, respectively, which generates a 19-cM locus for HP. Utilizing family members from the extended pedigree, a break in the high-risk haplotype between D7S684 and D7S661 was observed, which suggests it may be possible to exclude an additional 8 cM from the HP locus. A maximal pairwise logarithm of the odds score of 4.73 at a recombination fraction of theta at D7S684 was obtained with the addition of these extended family members. CONCLUSIONS: Linkage of HP to 7q35 represents a major advancement in our understanding of the genetic basis of this disorder.

Adult respiratory papillomatosis: human papillomavirus type and viral coinfections as predictors of prognosis.

Pathologic material and the records of 29 patients with laryngeal papillomatosis were reviewed. The relationship between the type of human papillomavirus (HPV) and the presence of viral coinfections was correlated with clinical outcome. Using polymerase chain reaction, paraffin-embedded specimens were analyzed for the presence of HPV, Epstein-Barr virus (EBV), cytomegalovirus (CMV), and herpes simplex virus (HSV). The HPV type could be identified in 24 patients' specimens. Twenty-one patients were infected with HPV type 6. The other 3 were infected with HPV type 11 or 16. Three patients developed squamous cell carcinoma, of whom 2 had HPV type 11 or 16. We found HSV, EBV, and CMV in 50%, 12.5%, and 0% of specimens, respectively. An aggressive clinical course was observed in 17 patients. Evidence of coinfection with other viruses was identified in 11 (65%) of these patients. In contrast, a benign clinical course was observed in 7 patients, of whom 2 (29%) had viral coinfections. We conclude that the HPV type and the presence of viral coinfections may be predictive of an aggressive clinical course.

Release of fatty acid-binding protein from ischemic-reperfused rat heart and its prevention by mepacrine.

In an attempt to resolve the issue of whether there is a loss of fatty acid binding protein (H-FABP) from heart during ischemia and reperfusion, and to further examine the role of this protein in ischemic-reperfusion injury, the amount of H-FABP of heart was monitored during ischemia and reperfusion. Excellent correlation was obtained between the loss of H-FABP from heart and its appearance in the perfusate buffer when examined by Western blot using the specific antibody to H-FABP. Further quantitation was achieved by densitometric scanning of the Western blot and rocket electrophoresis. Maximum release of H-FABP was observed within 20 min of reperfusion, the total release being 10% of the H-FABP content of the heart. Mepacrine, a membrane stabilizer and a phospholipase inhibitor, reduced the release of H-FABP from the heart and prevented the accumulation of nonesterified fatty acids in the tissue during ischemia and reperfusion. In view of the established role of H-FABP in the preservation of membrane phospholipids by either scavenging free radicals during ischemia and reperfusion or by modulating the enzymes of phospholipid synthesis, it seems likely that the loss of H-FABP may have some contribution towards the ischemic-reperfusion injury.

Effect of iron limitation on Bacteroides gingivalis.

This study was undertaken to describe the effects of iron limitation on Bacteroides gingivalis. Four strains of B. gingivalis were grown in brain heart infusion broth, substituting protoporphyrin IX for hemin. Culture with protoporphyrin IX resulted in a loss of a 28 kDa membrane protein, but no decrease in growth. Iron-restricted cultural conditions for the growth of B. gingivalis were achieved using alpha/alpha'-dipyridyl, a ferrous iron chelator, at concentrations from 12.5 microM to 300 microM. Total suppression of bacterial growth for strain A7A1-28 and strain 381 was achieved at 200 microM alpha/alpha'-dipyridyl. At 300 microM alpha/alpha'-dipyridyl, strain W50 and Bowden 18/10 showed 100% and 80% suppression of growth, respectively. The ferric iron chelator Desferal did not show suppression of growth in concentrations up to 500 microM. The dipyridyl inhibition of cell growth for strain A7A1-28 could be reversed by adding excess ferrous ammonium sulphate but not by ferric nitrate. Iron regulation of proteolytic enzymes could not be demonstrated. Two new membrane proteins 42 kDa and 24 kDa are expressed with iron limitation, and the 45 kDa membrane protein was decreased with iron limitation.

Proteolytic activity in black-pigmented bacteroides species.

Black-pigmented Bacteroides species are frequently found in dentoalveolar abscesses. One general mechanism of bacterial virulence is the production of extracellular enzymes which degrade connective tissue or molecules associated with host defense. In this study the proteolytic activity of 18 bacterial strains from 9 black-pigmented Bacteroides species was examined. Bacteroides gingivalis degraded the greatest number of substrates studied and produced the highest levels of enzymatic activity. B. gingivalis was the only species that degraded collagen and produced high levels of enzymes that degraded N-benzoyl-DL-arginine (BANA) and N-CBz-glycyl-glycyl-arginine. Bacteroides intermedius degraded several substrates including PZ peptide. Bacteroides endodontalis produced enzymes that degraded beta-naphthylamide derivatives of glycylproline and glycylphenylalanine. There were considerable differences in enzyme production between strains of the same species. Such heterogeneity between strains in the production of proteolytic enzymes may be relevant to the in vivo infections produced in the host.

Purification of an 80,000-Mr glycylprolyl peptidase from Bacteroides gingivalis.

An enzyme from Bacteroides gingivalis SUNYAB A7A1-28 that hydrolyzes the synthetic peptide glycyl-L-proline 4-methoxy-beta-naphthylamide was purified 1,040-fold by urea extraction, gel filtration, ion-exchange chromatography, and fast protein liquid chromatography. The molecular weight of the enzyme was 80,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 75,000 as determined by gel filtration. The optimum pH for the hydrolysis of glycyl-L-proline 4-methoxy-beta-naphthylamide was 7.5 to 8.5. The enzyme activity was inhibited by the serine protease inhibitors diisopropyl fluorophosphate and phenylmethylsulfonyl fluoride by 82.5 and 78%, respectively. The activity was also inhibited by Hg2+ (55.6%) and Zn2+ (45%).