Control of spermatozoan motility in a euryhaline teleost acclimated to different salinities

1984 ◽  
Vol 62 (12) ◽  
pp. 2674-2677 ◽  
Author(s):  
Brian Harvey ◽  
R. Norman Kelley

Motility in Oreochromis mossambicus spermatozoa was determined in mannitol solutions of varying osmolality. The number of spermatozoa activated was maximal in distilled water and declined with increasing osmolality. Transfer of males from freshwater to dilute seawater (22‰) and full seawater (35‰) increased motility at any given osmolality within 2 days. Spermatozoa from fish held at three test salinities showed varying degrees of motility at the mean osmolality of undiluted milt (321 mosmol/kg). Spermatozoa were fertile in full seawater, although motility in this medium and in a mannitol solution of the same osmolality was only 0.2%. The involvement of a second factor modulating spermatozoan motility in O. mossambicus is proposed.

1965 ◽  
Vol 49 (1) ◽  
pp. 1-16 ◽  
Author(s):  
M. Apostolakis

ABSTRACT A method for the extraction of prolactin from human pituitary glands is described. It is based on acetone drying, distilled water extraction, acetone and isoelectric precipitation. Two main products are obtained: Fraction R8 with a mean prolactin activity of 12.2 IU/mg and fraction U8 with a mean prolactin activity of 8.6 IU/mg. The former fraction does not contain any significant gonadotrophin activity and the latter contains on an average 50 HMG U/mg. In both cases contamination with ACTH and MSH is minimal. The growth hormone activity of both these fractions is low. It is postulated that in man too, prolactin and growth hormone are two distinct hormones. A total of 1250 human pituitary glands have been processed by this method. The mean prolactin content per pituitary gland has been found to be 73 IU.


Author(s):  
Giuseppe Lippi ◽  
Gabriel Lima-Oliveira ◽  
Giorgio Brocco ◽  
Antonella Bassi ◽  
Gian Luca Salvagno

AbstractBackground:Despite the importance of manual pipetting of fluids such as water, solutions, buffers, reagents, or biological samples in daily laboratory practice, the intra- and inter-individual imprecision of this activity has not been recently described in scientific publications.Methods:Twenty laboratory operators were randomly enrolled for this study. Imprecision of manual pipetting was estimated by asking each laboratory professional to dispense 1 mL, 100 μL or 10 μL of distilled water for 10 consecutive times with three certified pipettes into a 50-mL plastic container placed into a gravimetric balance. The weight of the water dispensed was systematically recorded for each of the 10 repeated attempts, and the inter- and intra-operator imprecision was finally calculated and expressed as coefficient of variation (CV%).Results:The mean intra-individual imprecision was 5.7% (range, 0%–11.8%) for pipetting 10 μL, 0.8% (range, 0.4%–1.9%) for pipetting 100 μL, and 0.2% (range, 0.1%–0.5%) for pipetting 1 mL. Overall, the mean inter-individual imprecision was 8.1% for pipetting 10 μL, 1.1% for pipetting 100 μL and 0.4% for pipetting 1 mL. A significantly inverse correlation was found between intra-individual pipetting imprecision and the amount of water dispensed (r = –0.80; p<0.001). No significant correlation was observed between individual pipetting performance and sex, age, qualification, and years of experience in the laboratory.Conclusions:The results of this study show that manual pipetting is plagued by a considerable intra- and inter-individual imprecision, which is inversely correlated with the amount of fluid dispensed.


Biotecnia ◽  
2020 ◽  
Vol 22 (2) ◽  
pp. 5-12
Author(s):  
Alejandro Mcdonal-Vera ◽  
Wilfrido M. Contreras-Sánchez ◽  
Neil J. Duncan ◽  
Kevin Fitzsimmons ◽  
Maria J. Contreras- García ◽  
...  

In the present investigation, we evaluated if the presence of tilapia affects growth and survival of shrimp during pre-growth and grow-out phases. In both experiments, we used a random-blocks design in a single earth pond (0.75 ha) that was prepared and divided into nine (7 x 30 m) enclosures that were considered to be three blocks of three enclosures each. Each randomly stocked block consisted on Pacific white shrimp Litopenaeus vannamei (30 shrimp/m2) and three different densities (0.0, 0.25 and 0.50 fish/m2) of red tilapia hybrids (Oreochromis mossambicus x Oreochromis niloticus) to give three different treatments with three replicates. The results from the pre-growth and grow-out experiments followed the same trend. In both cases, we found no significant statistical differences (P>0.05) in the final average weight of the shrimp. However, the experimental blocks had a significant (P<0.05) effect on the mean sample weight of shrimp. Shrimp in blocks B and C were significantly bigger than shrimp from block A (P<0.05). For both experiments, we found no effect of the presence of tilapias on survival or growth of shrimp.RESUMENEvaluamos si la presencia de tilapias libres afecta el crecimiento y la supervivencia de camarones en fase de preengorda y engorda. Para ambos experimentos, utilizamos un diseño de bloques al azar en un estanque rústico (0.75 ha) que fue preparado y dividido en nueve encierros (7 x 30 m), se formaron tres bloques con tres encierros cada uno. Cada encierro dentro de cada bloque fue aleatoriamente seleccionado para sembrar camarón blanco del Pacífico, Litopenaeus vannamei (30 camarones/m2) y tres diferentes densidades (0.0, 0.25 y 0.50 peces/m2) de híbrido de tilapia roja (Oreochromis mossambicus x Oreochromis niloticus) para formar tres tratamientos con tres réplicas. Los resultados del experimento de pre-engorda y engorda siguieron la misma tendencia. En ambos experimentos no encontramos diferencias estadísticamente en el crecimiento de los camarones ni en las tilapias. Sin embargo, los bloques experimentales presentaron diferencias significativas (P<0.05) en el peso promedio final. Los camarones de los bloques B y C fueron estadísticamente más grandes (P<0.05) que los del bloque A. Para las dos etapas de crecimiento de los camarones, no se observó un efecto de la presencia de tilapias sobre la sobrevivencia o crecimiento de los camarones.


SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A374-A375
Author(s):  
K K Pruss ◽  
D Willis ◽  
B J Spray ◽  
S Jambhekar

Abstract Introduction The Sleep Clinic at Arkansas Children’s follows approximately 300 children who require positive airway pressure (PAP) at home. The clinic respiratory therapist provides oral and written cleaning instructions while some physicians choose to provide their own instructions. The home equipment company who supplies PAP in the home also gives cleaning instructions. The different routes of information given may result in inconsistent practices. It is extremely important to clean PAP equipment as directed as infection and illness may result from improper cleaning. Methods Caregivers of children who utilize home PAP devices were invited to complete an anonymous survey regarding cleaning practices during a Sleep clinic appointment. Data were collected electronically. Descriptive statistics were utilized to summarize results. Results There were 96 participants of whom 90% (87/96) were parents/caregivers. The mean age of the equipment user was 12 years and most were male (69%, 66/96). The mean length of time the equipment had been used was 2.6 years (SD 3.2). The majority of respondents, 67% (64/95), identified the parent/caregiver as responsible for cleaning. Only 25% (24/96) reported cleaning the mask daily as recommended; 43% (41/96) of participants reported cleaning tubing weekly; 27% (26/96) reported cleaning the water chamber daily by while most reported at least weekly (47%, 45/96). The majority, 58% (56/96) reported emptying the water chamber daily and using distilled water (81%, 74/96). Most respondents did not note respiratory symptoms starting/increasing with PAP (67%, 64/96). Of those with respiratory symptoms attributed to PAP, congestion was the most common (79%, 11/14). Conclusion There is a discrepancy between recommended and actual practices for cleaning PAP equipment. No significant association was found between the duration of PAP use and cleaning practices. However, a moderately low correlation between age and cleaning was identified. Increased age was associated with decreased cleaning practices. Support  


2015 ◽  
Vol 309 (10) ◽  
pp. R1251-R1263 ◽  
Author(s):  
Mayu Inokuchi ◽  
Jason P. Breves ◽  
Shunsuke Moriyama ◽  
Soichi Watanabe ◽  
Toyoji Kaneko ◽  
...  

This study characterized the local effects of extracellular osmolality and prolactin (PRL) on branchial ionoregulatory function of a euryhaline teleost, Mozambique tilapia ( Oreochromis mossambicus). First, gill filaments were dissected from freshwater (FW)-acclimated tilapia and incubated in four different osmolalities, 280, 330, 380, and 450 mosmol/kg H2O. The mRNA expression of Na+/K+-ATPase α1a (NKA α1a) and Na+/Cl− cotransporter (NCC) showed higher expression with decreasing media osmolalities, while Na+/K+/2Cl− cotransporter 1a (NKCC1a) and PRL receptor 2 (PRLR2) mRNA levels were upregulated by increases in media osmolality. We then incubated gill filaments in media containing ovine PRL (oPRL) and native tilapia PRLs (tPRL177 and tPRL188). oPRL and the two native tPRLs showed concentration-dependent effects on NCC, NKAα1a, and PRLR1 expression; Na+/H+ exchanger 3 (NHE3) expression was increased by 24 h of incubation with tPRLs. Immunohistochemical observation showed that oPRL and both tPRLs maintained a high density of NCC- and NKA-immunoreactive ionocytes in cultured filaments. Furthermore, we found that tPRL177 and tPRL188 differentially induce expression of these ion transporters, according to incubation time. Together, these results provide evidence that ionocytes of Mozambique tilapia may function as osmoreceptors, as well as directly respond to PRL to modulate branchial ionoregulatory functions.


Author(s):  
Michael J. Buono ◽  
Michael Stone ◽  
Daniel T. Cannon

AbstractThe purpose of this study was to determine if KTwelve (six female, six male) healthy volunteers participated in this study. After thorough skin cleansing and preparation with isopropyl alcohol and high-performance liquid chromatography-grade distilled water, three sites were chosen and a 50 μL drop of artificial sweat was pipetted directly onto the skin. The artificial sweat had a [KThe mean (±SD) [KThese results do not support the hypothesis that significant K


1995 ◽  
Vol 198 (6) ◽  
pp. 1351-1357
Author(s):  
M Bijvelds ◽  
A Heijden ◽  
G Flik ◽  
P Verbost ◽  
Z Kolar ◽  
...  

The mechanism that underlies transcellular Ca2+ reabsorption in the kidney of the euryhaline teleost Oreochromis mossambicus was studied. Preparations of membrane vesicles made from the kidneys of freshwater- and seawater-adapted fish were more than sevenfold enriched in the basolateral plasma membrane marker Na+/K+-ATPase. Significant recovery of NADH&shy; cytochrome c reductase enzyme activity and of oxalate-stimulated Ca2+ pump activities in the membrane preparations indicated that the membrane fraction was of endoplasmic reticular origin. Indeed, thapsigargin specifically inhibited Ca2+ pump activity that could be attributed to oxalate-permeable endoplasmic reticular fragments. Kinetic analysis of thapsigargin-insensitive Ca2+ pump activity indicated the existence of a homogeneous, high-affinity, ATP-driven Ca2+ pump. No Na+-driven Ca2+ transport mechanism could be demonstrated. Plasma membrane Ca2+ pump activity was 56 % lower in preparations from seawater-adapted fish than in preparations from freshwater-adapted fish, suggesting a physiological role for this Ca2+ pump activity in renal Ca2+ handling by euryhaline species, with an involvement in the regulation of Ca2+ reabsorption.


2021 ◽  
Vol 52 (6) ◽  
pp. 1375-1381
Author(s):  
Z. K. Al – Timimi

The present study was aimed to investigate the possible effects caused by the antibiotic, metronidazole, on the histology of the testis and the morphology of the sperms of mice. To achieve this,  adult male albino Swiss Mice were orally administrated with 0.1 ml (100 mg\ kg ) of the commercially used metronidazole (Flagyl) for 60 consecutive days. The results showed significant decreases (p<0.05) in the mean weight of body and testis in the treated mice as compared to the distilled water-treated control group. The treatment also caused several histopathological changes in the testis which included necrosis, congestion, hemorrhage, edema, germ cell downfall  and rupture in the seminiferous tubules. The tests of the sperm morphology revealed a number of deformations as a result of the treatment, such as the appearance of headless,  bend, broken-tailed, hook-tailed, and two-headed sperms, as well as sperms with cytoplasmic droplets. We conclude that from these results that orally administered Metronidazole exerts negative effects on the male reproductive system of mice .


2005 ◽  
Vol 20 (2) ◽  
pp. 121-123 ◽  
Author(s):  
Luiz Eduardo Felipe Abla ◽  
Heitor Carvalho Gomes ◽  
Sandro Percario ◽  
Lydia Masako Ferreira

PURPOSE: Analyze the ability of Acetylcysteine to reduce distal necrosis in a random skin flap, in the rat. METHODS: The present study utilized 28 adult male Wistar-EPM rats distributed, at random, in two groups of 14 animals. Control group rats (CG) received distilled water and Acetylcysteine group animals (NACG) received NAC (300 mg/kg) by oral infusion, 15 minutes before flap elevation. On the seventh postoperative day, percentage of distal necrosis was determined and skin samples collected in order to allow determination of MDA levels. RESULTS: The mean necrotic area in CG group (control) was 66 % and in NACG group (Acetylcysteine) 52 %, a statistically significant difference according to the Mann-Whitney test (U calc = 25; U crit = 45). MDA levels were lower in the CG flap skin samples than in the NACG samples (U calc = 24; U crit = 45), the oposite being true in the normal skin samples (U calc = 10; U crit = 45). CONCLUSION: Acetylcysteine was effective, according to the model used, reducing the percentage of distal necrosis in NACG rats.


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