71 Comparison of sexed semen ULTRA-4M with conventional semen for the invitro production of bovine embryos

2020 ◽  
Vol 32 (2) ◽  
pp. 161
Author(s):  
H. Alvarez ◽  
M. Kjelland ◽  
F. Villaseñor ◽  
M. Pérez ◽  
S. Romo
Keyword(s):  
Sperm Concentration ◽  
Physiological Saline ◽  
Field Trials ◽  
Penicillin G ◽  
Cleavage Rate ◽  
Cattle Industry ◽  
The United Kingdom ◽  
Sexed Semen ◽  
Physiological Saline Solution ◽  
Α Level

The first commercial production of sexed semen was at the Cogent company in the United Kingdom. Since then millions of offspring have been born using sexed semen produced by flow cytometry. Sexed semen technology has recently been modernized to what is now known as ULTRA (ST Genetics), completely modifying the technique, medium, and sperm concentration. In field trials using AI, there was no difference between conventional semen (CONV) and ultra-sexed semen at a concentration of 4 million sperm per straw (ULTRA-4M). The combination of invitro embryo production (IVP) and sexed semen technologies has been successful for intensity selection in the cattle industry. The objective of this work was to compare the CONV and ULTRA-4M semen for bovine IVP. The research was carried out in the reproduction laboratory at the Facultad de Estudios Superiores Cuautitlán-Universidad Nacional Autónoma de México (FESC-UNAM). The IVP was performed with a continuous invitro culture (IVC) system. Ovaries (n=213) were collected from a slaughterhouse (Querétaro, México) and transported to the laboratory within 2h (FESC-UNAM) in physiological saline solution (0.9% NaCl) supplemented with penicillin G (100IUmL−1) and streptomycin sulfate (100µgmL−1). For IVP, VITROGEN media were used for IVM, IVF, and IVC. For the IVM, the cumulus-oocyte complexes were selected (only grades 1 and 2) and matured for 24h at 38.5°C in 5% CO2, 95% air, and 100% humidity. Matured oocytes (n=1000) were divided into two groups, the CONV group and the ULTRA-4M group. The IVF process was developed with CONV and ULTRA-4M semen from the same bull (Holstein) at a concentration of 2×106 and 0.5×106 spermmL−1, respectively, for 18h in 38.5°C, 5% CO2, 95% air, and 100% humidity. The presumptive zygotes were denuded by pipetting and left in IVC until Day 7 at 38.5°C, 5% CO2, 5% O2, and 90% N2 at 100% humidity. The cleavage rate, embryos of more than 6 cells, and blastocysts on Day 7 of culture were evaluated. The statistical analysis was carried out with the GLM procedure of the SAS software (version 9.3; SAS Institute Inc.) to evaluate the results of CONV vs. ULTRA-4M (α level=0.05). Percent cleavage for CONV was 72.2%±2.53 and 75.6%±2.53 for ULTRA-4M. For embryos with more than 6 cells, the results for CONV and ULTRA-4M were 59.8%±5.61 and 62.8%±5.61, respectively. The percentage of blastocysts on Day 7 was 37.8%±5.39 for CONV and 43.6%±5.39 for ULTRA-4M. There were no significant differences between the groups (P>0.05) for all variables analysed. Although the number of blastocysts on Day 7 were numerically higher in the ULTRA-4M, differences were not significant. In conclusion, under the conditions of this research the ULTRA-4M had similar results as CONV for bovine IVP.

51 Comparison of SexedULTRA 4M and conventional semen for invitro production of bovine embryos using two bulls

2021 ◽  
Vol 33 (2) ◽  
pp. 132
Author(s):  
H. Álvarez-Gallardo ◽  
M. Kjelland ◽  
M. Pérez-Martínez ◽  
F. Villaseñor-González ◽  
S. Romo
Keyword(s):  
Physiological Saline ◽  
Penicillin G ◽  
Bovine Embryos ◽  
Streptomycin Sulphate ◽  
Cleavage Rate ◽  
Cattle Industry ◽  
Sexed Semen ◽  
Physiological Saline Solution ◽  
Sorting Process ◽  
Α Level

SexedULTRA 4M™ (Select Sires) is made using an improved method of sex-sorting sperm in a less damaging environment for retaining sperm integrity through the sorting process. The combination of invitro embryo production (IVP) and sexed semen technologies has been successful for intensity selection in the cattle industry. The objective of this research was to compare conventional (CONV) and SexedULTRA 4M (ULTRA-4M) semen for bovine IVP using 2 bulls. The research was carried out in the reproduction laboratory at Palominos Ranch (Jalisco, México). The IVP was performed with a continuous invitro culture system. Ovaries from commercial cattle (n=213) were collected from a slaughterhouse (León, México) and transported to the laboratory within 2h in physiological saline solution (0.9% NaCl) supplemented with penicillin G (100IUmL−1) and streptomycin sulphate (100µg mL−1). For IVP, IVF Bioscience™ media were used for IVM, IVF, and invitro culture (IVC). For the IVM, the cumulus–oocyte complexes (COCs) were selected (grades 1 and 2) and matured for 24h at 38.5°C in 5% CO2 in air and 100% humidity. Matured oocytes (n=1200, divided equally into 3 replicates) were divided into 2 groups, the CONV group and the ULTRA-4M group. The IVF process was conducted with both CONV and ULTRA-4M semen from the 2 bulls, separately, at an adjusted concentration of 2×106 and 0.5×106 sperm mL−1, respectively, for 18h in 38.5°C, 5% CO2 in air, and 100% humidity. The presumptive zygotes were denuded by pipetting and set in IVC until Day 7 at 38.5°C, 5% CO2, 5% O2 and 90% N2 at 100% humidity. The cleavage rate, embryos with more than 6 cells, and blastocysts on Day 7 of culture were evaluated. Statistical analysis was carried out with the GLM procedure of SAS (version 9.3; SAS Institute Inc.) to evaluate the results of CONV versus ULTRA-4M for each bull (α level=0.05). Cleavage rates were 57.1%±1.5 and 59.4%±1.5, respectively in CONV and ULTRA-4M groups with Bull 1 and 43.3%±1.5 and 45.2%±1.5 with Bull 2. The percentages of embryos with more than 6 cells were 51.4%±1.0 and 53.9%±1.0, respectively, with CONV and ULTRA-4M with Bull 1 and 30.4%±1.0 and 33.4%±1.0 with Bull 2. The percentage of blastocysts on Day 7 with Bull 1 was 34.4%±1.7 for CONV and 36.2%±1.7 for ULTRA-4M; for Bull 2, the results were 26.5%±1.7 for CONV and 29.5%±1.7 for ULTRA-4M. There were no significant differences between the CONV and ULTRA-4M groups (P>0.05) for all variables analysed for each bull; however, Bull 1 was significantly superior to Bull 2 for all variables analysed. In conclusion, under the conditions of this research, ULTRA-4M and CONV semen produced similar bovine IVP results.

72 Invitro embryo production using prepubertal calf oocytes with conventional semen and sexed semen ULTRA-4M

2020 ◽  
Vol 32 (2) ◽  
pp. 162
Author(s):  
A. Velazquez ◽  
H. Alvarez ◽  
M. Kjelland ◽  
F. Villaseñor ◽  
G. Ariza ◽  
...  
Keyword(s):  
Bos Taurus ◽  
Bos Indicus ◽  
Sperm Concentration ◽  
Reproductive Potential ◽  
The United States ◽  
Field Trials ◽  
Cleavage Rate ◽  
Embryo Production ◽  
Sexed Semen ◽  
Α Level

Invitro embryo production (IVP) can increase the reproductive potential and genetic quality of cattle, as well as other species. This powerful assisted reproduction tool can be used to produce embryos from prepubertal calves, reducing the generation interval. A recent sexed semen technology known as ULTRA (ST Genetics), completely modified the technique, the media and sperm concentration. In field trials with AI there was no difference between conventional semen (CONV) and ultra-sexed semen at a concentration of 4 million per straw (ULTRA-4M). The combined use of IVP and ULTRA-4M can decrease the selection time for improving dairy and beef cattle herd genetics. The objective of this research was to compare the CONV and ULTRA-4M semen using bovine IVP and prepubertal calves. The research was carried out in the reproduction laboratory of the Facultad de Estudios Superiores Cuautitlán - Universidad Nacional Autónoma de México (FESC-UNAM). The IVP was performed with a continuous invitro culture (IVC) system. The ovaries were collected in Campeche, México, from Bos indicus×Bos taurus crossbred calves (6 months old) using surgical castration (for export to the United States) and transported to the laboratory (FESC-UNAM) in BO-HEPES-IVM (Bioscience™), in an oocyte transporter (WTA). Vitrogen media were used for IVF and IVC. For IVM, the cumulus-oocyte complexes (COCs) were selected (only grades 1 and 2) and matured for 24h at 38.5°C. Matured oocytes (n=600, divided equally into five replicates) were divided into 2 groups, the CONV group and the ULTRA-4M group. The IVF process was conducted with CONV and ULTRA-4M semen from the same bull (Holstein) at a concentration of 2×106 and 0.5×106 spermatozoamL−1, respectively, for 18h in 38.5°C, 5% CO2, 95% air, and 100% humidity. The presumptive zygotes were denuded by pipetting and set in IVC until Day 7 at 38.5°C, 5% CO2, 5% O2, and 90% N2 at 100% humidity. The cleavage results were recorded 56h after the beginning of IVC. The cleavage rate, embryos with more than 6 cells, and blastocysts on Day 7 of culture were evaluated. The statistical analysis was carried out with the GLM procedure of the SAS software (version 9.3; SAS Institute Inc.) to evaluate the results of CONV vs. ULTRA-4M (α level=0.05). The percentage of cleavage for CONV was 46%±1.4 and 43.2%±1.4 for ULTRA-4M. The results for embryos with more than 6 cells in the CONV and ULTRA-4M groups were 16%±0.6 and 14%±0.6, respectively. The percentage of blastocysts on Day 7 for CONV was 9%±0.6 and 8%±0.6 for ULTRA-4M. There were no significant differences between groups (P>0.05) for all variables analysed. In conclusion, under the conditions of this research the ULTRA-4M and CONV produced similar results for IVP.

69 Invitro production of ovine embryos using either fresh or frozen-thawed semen

2021 ◽  
Vol 33 (2) ◽  
pp. 141
Author(s):  
G. Márquez-Márquez ◽  
A. Velázquez-Roque ◽  
F. Villaseñor-González ◽  
M. Kjelland ◽  
H. Álvarez-Gallardo ◽  
...  
Keyword(s):  
Semen Quality ◽  
Small Ruminants ◽  
Physiological Saline ◽  
Ovis Aries ◽  
Penicillin G ◽  
Domestic Sheep ◽  
Assisted Reproductive Technique ◽  
Physiological Saline Solution ◽  
Α Level ◽  
Fresh Semen

Invitro embryo production (IVP) is an important tool for genetic improvement in small ruminants. Semen quality is one of the most important aspects to consider for the success of this assisted reproductive technique. With ovine IVP, it is a common practice to use fresh semen for IVF, but this could be a problem because the differences between ejaculates from the same animal are well documented and a source of variation in IVP results. The objective of this research was to compare the effect of fresh and frozen–thawed domestic sheep (Ovis aries) semen on IVF for ovine IVP. The research was carried out in the reproduction laboratory at the Palominos Ranch (Jalisco, México). The IVP was performed with a continuous invitro culture system. Ovaries (n=186) were collected from a slaughterhouse (León, México) and transported to the laboratory within 2h in physiological saline solution (0.9% NaCl) supplemented with penicillin G (100IU mL−1) and streptomycin sulphate (100µg mL−1). For IVP, IVF-Bioscience™ media were used for IVM, IVF, and invitro culture (IVC). For IVM, the cumulus–oocyte complexes (COCs) were selected (only grades 1 and 2) and matured for 24h at 38.5°C in 5% CO2 in air and 100% humidity. Matured oocytes (n=1000) were invitro fertilized using either fresh or frozen–thawed semen (Triladyl™; Minitube) from the same sheep, at a concentration of 2×106 sperm mL−1, for 18h in 38.5°C, 5% CO2 in air, and 100% humidity. The presumptive zygotes were denuded by pipetting and set in IVC until Day 7 at 38.5°C, 5% CO2, 5% O2, and 90% N2 at 100% humidity. The percentages of cleavage, embryos with more than 6 cells, and blastocysts on Day 7 of culture were evaluated, based on the initial number of oocytes entering into IVM. Statistical analyses were carried out with the GLM procedure of SAS software (version 9.3; SAS Institute Inc.) to evaluate the results of fresh versus frozen–thawed (α level=0.05). Rates of cleavage, embryos with more than 6 cells, and blastocysts on Day 7 were similar (P>0.05): fresh 52.3±3.0%, 43.6±2.6%, and 34.3±2.9%, respectively; frozen–thawed: 53.3%±3.0, 41.1±2.6%, and 33.3±2.9%, respectively. In conclusion, under the conditions of this research, the use of fresh and frozen–thawed semen had similar results for ovine IVP.

68 Comparison of two Percoll gradients for selection of frozen semen for invitro production of ovine embryos

2021 ◽  
Vol 33 (2) ◽  
pp. 141
Author(s):  
A. Velázquez-Roque ◽  
F. Villaseñor-González ◽  
G. Márquez-Márquez ◽  
M. Kjelland ◽  
H. Álvarez-Gallardo ◽  
...  
Keyword(s):  
Sperm Quality ◽  
Physiological Saline ◽  
Bottom Layer ◽  
Penicillin G ◽  
Sperm Selection ◽  
Percoll Gradient ◽  
Cleavage Rate ◽  
Frozen Semen ◽  
Percoll Gradients ◽  
Α Level

Sperm selection methods are routinely applied to prepare semen for IVF in animal species. These procedures are used to improve sperm quality characteristics as well as to remove other background material and debris. Percoll gradient is widely used in animal IVF laboratories. Different Percoll gradient concentrations and volumes can be used to improve the sperm sample motility percentage. The objective of this research was to evaluate the effect of 2 different Percoll concentrations for ovine IVF sperm selection and effects, if any, on invitro embryo production (IVP). Specifically, Percoll gradients consisted of Group 1 (G1) 40–80% and Group 2 (G2) 45–90%, 400µL each. The research was carried out in the reproduction laboratory at Palominos Ranch (Jalisco, México). The IVP was performed with a continuous invitro culture system. Ovaries (n=157) were collected from a slaughterhouse (León, México) and transported to the laboratory within 2h in physiological saline solution (0.9% NaCl) supplemented with penicillin G (100IU mL−1) and streptomycin sulphate (100µg mL−1). For IVP, IVF Bioscience™ media were used for IVM, IVF, and invitro culture (IVC). For IVM, the cumulus–oocyte complexes (COCs) were selected (only grades 1 and 2) and matured for 24h at 38.5°C in 5% CO2 in air and 100% humidity. Matured oocytes (n=800, divided equally into 4 replicates) were divided into 2 groups, G1 and G2. The IVF process was conducted with semen selected through a mini-Percoll technique with gradients at a concentration of 45% (top layer) and 90% (bottom layer) or 40% (top layer) and 80% (bottom layer) for G1 and G2, respectively, using frozen–thawed semen from the same ram, at a concentration of 2×106 sperm mL−1, for 18h in 38.5°C, 5% CO2 in air, and 100% humidity. The presumptive zygotes were denuded by pipetting and set in IVC until Day 7 at 38.5°C, 5% CO2, 5% O2, and 90% N2 at 100% humidity. The percentages of cleavage, embryos with more than 6 cells, and blastocysts on Day 7 of culture were evaluated, based on the initial number of oocytes entering into IVM. The statistical analyses were carried out with the GLM procedure of SAS software (version 9.3; SAS Institute Inc.) to evaluate the results of G1 versus G2 (α level=0.05). Cleavage rate was 47.8%±2.5 and 55.9%±2.5, respectively, in G1 and G2. The percentages of embryos with more than 6 cells were 38.1%±2.2 and 43.5%±2.2, respectively, in G1 and G2. The percentage of blastocysts on Day 7 was 27.4%±1.1 and 37.3%±1.1, respectively, in G1 and G2. There were no significant differences between groups (P>0.05) for percentage of cleavage and embryos with more than 6 cells, although the percentage of cleavage tended to be greater for G2 (P=0.06). Additionally, G2 had a larger percentage of blastocysts on Day 7 compared with G1 (P<0.05). In conclusion, under the conditions of this research, the use of a Percoll gradient at a concentration of 40–80% increased the percentage of blastocysts for ovine IVP.

271 USE OF SEXED SEMEN FOR BOVINE IVF IN MEXICO: PRELIMINARY RESULTS

2006 ◽  
Vol 18 (2) ◽  
pp. 243
Author(s):  
J. Aysa ◽  
J. A. Medrano ◽  
A. Villa-Godoy ◽  
A. Barba ◽  
Y. C. Ducolomb ◽  
...  
Keyword(s):  
Sperm Concentration ◽  
Physiological Saline ◽  
Control Group ◽  
Concentration Gradients ◽  
Vitro Fertilization ◽  
Sexed Semen ◽  
Fort Collins ◽  
Vitro Development ◽  
Economic Improvement

The use of sexed embryos in dairy cattle is useful for the genetic and economic improvement of production. The aim of this study was to determine differences in in vitro maturation (IVM), in vitro fertilization (IVF), and in vitro development (IVD) with the use of sexed and unsexed sperm. Semen from one Holstein bull was used for the experiment. The semen was sexed and frozen by X-Y, Mexico (subsidiary of X-Y Inc., Fort Collins, CO, USA). Only the X fraction of spermatozoa was sorted and frozen in 0.25-mL plastic straws with 2.0 � 106 spermatozoa/straw. A modified protocol for IVF was used. A total of 334 ovaries were obtained from a local slaughterhouse and transported to the laboratory in physiological saline (25�C). From these, 1019 cumulus-oocyte complexes (COCs) were obtained and used for the procedures of IVM, IVF, and IVD. The average number of follicles aspirated per ovary was 3.6, and an average of 3.05 COCs were recovered per ovary. The oocyte recovery rate was 85%. For IVM, COCs were incubated in TCM-199 supplemented with BSA, pyruvate, FSH, and LH for 24 h. All incubations were performed at 38.5�C in a humidified atmosphere of 5% CO2 in air. After this period, COCs were placed in fertilization medium (TALP supplemented with BSA, heparin, penicillamine, and hypotaurine). For IVF, oocytes were randomly assigned to two groups: sexed semen (Holstein) or treatment group (TG), and non-sexed semen (Brahman, used as control in our laboratory) or control group (CG). For insemination, frozen-thawed semen from the Holstein and Brahman bulls was washed by centrifugation in two concentration gradients of a silicone solution. In both groups, sperm concentration used for IVF was 1 � 106 spermatozoa/mL. After insemination, oocytes and semen were co-incubated for 18 h. For IVD, presumptive zygotes were incubated for 7 days in a modified IVD medium (Barc-1) supplemented with BSA. The degree of IVD was evaluated according to the number of divisions of the embryos produced, and the number of embryos that developed to the morula and blastocyst stages. Five replicates were made. The rates of IVM, IVF, and IVD were analyzed by logistic regression. The COCs produced 890 fertilized oocytes. Of these, 442 were from the TG and 448 from the CG. A total of 393 embryos from the TG and 372 from the CG developed in vitro; embryos were evaluated for development on Day 7. A total of 108 morulae (21%) were produced in the TG and 100 (19%) in the CG, whereas 99 (19%) blastocysts developed in the TG and 105 (20%) in the CG. There were no statistically significant differences between the two groups studied for embryo IVD (P > 0.05). It is concluded that IVM, IVF, and IVD procedures used for conventional non-sexed semen can be used for similar results with sperm sexed by flow cytometry. This is the first report of sexed semen use for bovine IVF in Mexico and is a precedent for future investigations on in vitro embryo production in Mexico. More experiments are needed to confirm these preliminary findings. Sexed semen was provided by Rancho El Nacimiento, Establo 196, Tizayuca, State of Hidalgo, M�xico. Funding for J. A. was provided by CONACYT and UNAM.

Sem Studies of Co-Cr-Mo Surgical Implant Alloy Corrosion Behavior

1982 ◽  
Vol 40 ◽  
pp. 520-521
Author(s):  
Ann Chidester Van Orden ◽  
John L. Chidester ◽  
Anna C. Fraker ◽  
Pei Sung
Keyword(s):  
Electron Microscopy ◽  
Corrosion Behavior ◽  
Anodic Polarization ◽  
Saline Solution ◽  
Saturated Calomel Electrode ◽  
Physiological Saline ◽  
X Ray ◽  
Physiological Saline Solution ◽  
Scanning Electron

The influence of small variations in the composition on the corrosion behavior of Co-Cr-Mo alloys has been studied using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and electrochemical measurements. SEM and EDX data were correlated with data from in vitro corrosion measurements involving repassivation and also potentiostatic anodic polarization measurements. Specimens studied included the four alloys shown in Table 1. Corrosion tests were conducted in Hanks' physiological saline solution which has a pH of 7.4 and was held at a temperature of 37°C. Specimens were mechanically polished to a surface finish with 0.05 µm A1203, then exposed to the solution and anodically polarized at a rate of 0.006 v/min. All voltages were measured vs. the saturated calomel electrode (s.c.e.).. Specimens had breakdown potentials near 0.47V vs. s.c.e.

Erythrophagocytosis by Entamoeba histolytica.- Ultrastructural Study

1972 ◽  
Vol 30 ◽  
pp. 156-157 ◽  
Author(s):  
Norberto Treviño ◽  
Alfredo Feria-Velasco ◽  
I. Ruiz de Chávez
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Entamoeba Histolytica ◽  
Ultrastructural Study ◽  
Saline Solution ◽  
Physiological Saline ◽  
Ultrastructural Level ◽  
Hot Plate ◽  
Physiological Saline Solution ◽  
Axenic Conditions

Although erythrophagocytosis by various species of Entamoeba is a well known phenomenon this has not yet been studied in detail at the ultrastructural level. The present work deals with the description of the incorporation process of erythrocytes by trophozoites of E. histolytica. For this study, trophozoites of E. histolytica, HK-9:NIH strain cultured in axenic conditions and washed human erythrocytes were placed on a hot plate at 37°C in physiological saline solution. After 5 minutes, 2.5% glutarldehyde was added and the samples were processed according to conventional techniques for electron microscopy.Based upon light microscopy studies on living trophozoites in contact with erythrocytes, it seems that erythrophagocytosis only takes place in one pole of the parasite.

Resection of bone by sagittal saw: Investigation of effects of blade speed, feed rate, and irrigation on temperature rise

2021 ◽  
pp. 095441192199948
Author(s):  
Ehsan Shakouri ◽  
Pezhman Ghorbani ◽  
Pedram Pourheidari ◽  
Saeed Fotuhi
Keyword(s):  
Temperature Rise ◽  
Feed Rate ◽  
Saline Solution ◽  
Physiological Saline ◽  
The State ◽  
Physiological Saline Solution ◽  
Allowable Range ◽  
Dry Conditions ◽  
Saw Blade ◽  
Oscillation Rate

Heat generation during bone cutting by sagittal saw may lead to temperature rise and possible incidence of thermal necrosis. The aim of the present research is to examine the effect of saw blade oscillation rate, blade feed rate, and irrigation by physiological saline solution on the bone temperature rise during sawing in order to determine the desired conditions for reducing the extent of thermal damage. For this purpose, empirical tests of bovine femur cutting were performed in 15 states, including five levels for the blade oscillation rate (10,000–18,000 cpm with 2000 cpm intervals) and three levels for the feed rate (10–30 mm.min−1 with 10 mm.min−1 intervals) for dry conditions; and five states, including five levels for the blade oscillation rate (10,000–18,000 cpm with 2000 cpm intervals) and one level in feed rate of 20 mm.min−1 for the irrigation conditions. The results indicated that the bone temperature rise had a direct relationship with the blade oscillation rate and an inverse relationship with its feed rate. In the state of no cooling, the minimum temperature rise (Δ T = 65.45°C) occurred at the blade speed of 10,000 cpm and feed rate of 30 mm.min−1, while in the state of sawing with irrigation, the temperature rise almost did not exceed the allowable range (Δ T ≤ 10°C). The results suggested that to lower the possibility of incidence of osteonecrosis in the bone resection by sagittal saw, cooling with physiological saline solution or application of the minimum blade oscillation rate and maximum feed rate is recommended.

scholarly journals A Study of the Diverse Races of Entamoeba histolytica distinguishable from one another by the dimensions of their Cysts

Parasitology ◽  
1918 ◽  
Vol 10 (3) ◽  
pp. 320-351 ◽  
Author(s):  
Clifford Dobell ◽  
Margaret W. Jepps
Keyword(s):  
Entamoeba Histolytica ◽  
Saline Solution ◽  
Practical Importance ◽  
Physiological Saline ◽  
E Coli ◽  
True Value ◽  
Apparent Loss ◽  
Physiological Saline Solution ◽  
Apparent Reduction ◽  
Pure Lines

1. Entamoeba histolytica Schaudinn (vel E. dysenteriae Councilman and Lafleur), the human dysentery amoeba, is a collective species. It comprises a number of distinct races, strains, or pure lines, distinguishable from one another by the size of the cysts which they produce.2. How many such distinct races exist is still undetermined; but we have demonstrated the existence of at least five.3. There is no evidence that the different races differ in their geographical distribution, or in any character save size.4. These races remain constant in character within a given host; and the dimensions of the cysts are not determined by the action of the host upon the parasite, since two different races may coexist side by side in the same host.5. Different values for the dimensions of the cysts are obtained when these are measured in different media. Taking the measurements of living cysts suspended in physiological saline solution as representing the true value, we find that the dimensions of cysts in iodine solution are approximately the same; but that cysts which have been suitably fixed, stained, and mounted in balsam, have undergone an apparent reduction of approximately 10% from the true diameter.6. The most suitable fixative for E. histolytica cysts we have found to be a modification of Schaudinn's fluid. (Saturated aqueous solution of corrosive sublimate, two parts; absolute alcohol, one part; glacial acetic acid, 4–5%.) Cysts fixed in this fluid undergo no measurable shrinkage or swelling in the process.7. The apparent loss of size observed in cysts which have been fixed, stained, and mounted in balsam, is due chiefly to the invisibility of the cyst wall in the mounting medium.8. It follows from what has been said above (5 and 6) that to obtain an approximately true value for the dimensions of the living cysts from measurements made upon those suitably fixed, stained, and mounted in balsam, these measurements should be multiplied by the factor 9. We find no evidence of the existence of a sexual dimorphism in the cysts belonging to a single race, such as has been described by Mathis and Mercier.10. Since cysts of E. histolytica may be found with all diameters from about 5μ. to about 20μ—a range overlapping or covering the dimensions of the cysts of the two common harmless intestinal amoebae of man (E. coli and E. nana) and of other cysts and cyst-like bodies occurring in human faeces—it is of considerable practical importance to recognize and distinguish the diverse races of E. histolytica which differ from one another in the dimensions of the cysts which they produce.

On intravenous infusions for blood loss

1927 ◽  
Vol 23 (3) ◽  
pp. 350-350
Author(s):  
N. D. Perumov
Keyword(s):  
Blood Loss ◽  
Saline Solution ◽  
Physiological Saline ◽  
Physiological Solution ◽  
Single Infusion ◽  
Intravenous Infusions ◽  
Physiological Saline Solution

The author believes that the infusion of gummy-arabic solution and the drip method of intravenous infusions of physiological saline solution are approximately equivalent and superior to a simple single infusion of physiological solution.

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