57 THE EFFECT OF VITRIFICATION FOR SHEEP EMBRYO VIABILITY

2015 ◽  
Vol 27 (1) ◽  
pp. 121
Author(s):  
G. A. Valieva ◽  
M. M. Toishibekov ◽  
S. M. Askarov ◽  
B. B. Molzhigitov
Keyword(s):  
Developmental Competence ◽  
Embryo Cryopreservation ◽  
Crystal Formation ◽  
Ice Crystal ◽  
Embryo Viability ◽  
Fresh Frozen ◽  
Loop Volume ◽  
Student’S T ◽  
Phosphate Buffered Saline ◽  
Student’S T Test

This work evaluated different methods for sheep embryo cryopreservation by vitrification (V) and super-cooling ultra-rapid vitrification (SCURV). The vitrification method was applied according to the method described by Vajta et al. Both treatments used a vitrification solution (VS) containing 20% ethylene glycol, 20% dimethylsulfoxide (Me2SO), 0.5 mol L–1 sucrose in Dulbecco's phosphate buffered saline (DPBS) with 10% BSA. The super-cooled LN facilitates heat transmission between LN and the cryosolution interface, and this is efficient for bovine semen and blastocyst cryoconservation (Arav et al. 2002). By surgical flushing 25 super-stimulated ewes, 109 transferable morulae were harvested; 35 morulae were transferred fresh to synchronized recipients (control) and the others were cryopreserved by V (n = 36) or SCURV (n = 38), respectively, thawed or warmed, and transferred to recipients. Embryos were vitrified using the HSV Kit. They were first incubated in 50% VS for 2 min and then transferred for 30 s into 100% VS. Each embryo was loaded by HSV Kit, which was immediately submerged into and stored in LN. Warming was done by placing the narrow end of the straw into DPBS + 0.25 M sucrose for 5 min. Embryos were then transferred into DPBS + 0.125 M sucrose for 3 min and finally to DPBS until transfer. The SCURV morulae were then exposed to 50 and 100% VS at 37°C for 2 min and 30 s, respectively. Embryos after saturation in VS were transferred on a surface of a nylon loop (volume 20 μL, diameter 0.5 mm) and using negative pressure of LN in the chamber for freezing with the VIT-Master. Thawing vitrified embryos was accomplished by placing the vitrified embryos in solutions of sucrose 0.25 M and 0.125 M with expositions 2 and 3 min accordingly. After thawing embryos, only good-quality embryos were transferred. Statistical analyses were performed with Student's t-test. The lambing rate following transfer of fresh, frozen-thawed vitrification and SCURV methods were 18, 12, 14 lambs accordingly. No statistical difference was found for the percentage of does lambing following transfer thawed after vitrification (33.4 ± 5.2a%) and SCURV methods (36.8 ± 6.3b%). The survival rate following transfer of fresh embryos (51.4 ± 4.8c) was higher and in line with previous findings using VS. Differences were statistically significant (ac,bc P < 0.05). Importantly, our data suggest that the HSV Kit can be used to produce viable morulae for implantation as the SCURV, and to as vitrification method. Although further work on the developmental competence of embryos cryopreserved with the SCURV method are needed, these data suggest that with SCURV a faster freeze rate and lower level of cryoprotectants is able to minimize ice crystal formation and should be further evaluated as a routine mechanism for cryopreserving sheep embryos.

44 SUCCESSFUL KIDDING AFTER ULTRARAPID VITRIFICATION OF GOAT EMBRYOS

2017 ◽  
Vol 29 (1) ◽  
pp. 129
Author(s):  
Y. Toishibekov ◽  
M. Yermekova
Keyword(s):  
Survival Rate ◽  
Liquid Nitrogen ◽  
Statistical Difference ◽  
Developmental Competence ◽  
Crystal Formation ◽  
Ice Crystal ◽  
Heat Transmission ◽  
Bovine Semen ◽  
Fresh Frozen ◽  
Fresh Embryos

This work evaluated methods for goat morulae cryopreservation by using cryoloop: vitrification (V) and super-cooling ultra-rapid vitrification (SCURV). The vitrification method was applied according to the method described by Vajta et al. (1998 Mol. Reprod. Dev. 51, 53–58). Both treatments used a vitrification solution [VS: 20% (3.6 mol L−1), ethylene glycol (EG), 20% (2.4 mol L−1) dimethylsulfoxide (Me2SO)] 0.5 mol L−1 sucrose in DPBS with 10% BSA in both methods. In our experiment, we used the Vit-Master™ (MTG, Bruckberg, Germany). The super-cooled LN facilitates heat transmission between LN and the cryosolution interface and this is efficient for bovine semen and blastocyst cryoconservation (Arav et al. 2002 Mol. Cell. Endocrinol. 187, 77–81). By surgical flushing 25 super stimulated goats, 127 transferable morulae were harvested; 39 morulae were transferred fresh to synchronized recipients (control) and the others were cryopreserved by V (n = 46) or SCURV (n = 42), respectively thawed or warmed, and transferred to recipients. Embryos were vitrified using the cryoloop. They were first incubated in 50% VS for 2 min and then transferred for 30 s into 100% VS. Each embryo was loaded by cryoloop, which was immediately submerged into and stored in liquid nitrogen. Warming was done by placing the narrow end of the cryoloop into DPBS + 0.25 M sucrose for 5 min. Embryos were then transferred into DPBS + 0.125 M sucrose for 3 min and finally to DPBS until transfer. The SCURV morulae were then exposed to 50% and 100% VS at 37°C for 2 min and 30 s, respectively. Embryos after saturation in VS were transferred by cryoloop and using negative pressure of liquid nitrogen in the chamber for freezing with the VIT-Master. Thawing vitrify embryos was accomplished by placing the vitrified embryos in solutions of sucrose 0.25 M and 0.125 M with 2- and 3-min exposures accordingly. After thawing, embryos were transferred. Statistical analysis was done using Student’s test. The kidding rate following transfer of fresh, frozen-thawed vitrification, and SCURV methods were 22, 16, and 16 kids, respectively. No statistical difference was found for the percentage of does kidding following transfer thawed after vitrification (34.7 ± 4.5%a), and SCURV methods (38.1 ± 5.9%b). The survival rate following transfer of fresh embryos (56.4 ± 4.9c) was higher and in line with previous findings using VS. Differences were statistically significant (ac, bc P < 0.05). Importantly, our data suggested that the SCURV method can be used for cryopreservation of goat morulae and has similar success to the vitrification method. While further work on the developmental competence of embryos cryopreserved with the SCURV method is needed, we hypothesise that SCURV, with a faster freeze rate and potentially a lower level of cryoprotectants, may be able to minimize ice crystal formation; SCURV should be further evaluated as a routine mechanism for cryopreserving goat embryos.

120 SUCCESSFUL LAMBING AFTER SUPER-COOLING ULTRARAPID VITRIFICATION SHEEP MORULAE

2010 ◽  
Vol 22 (1) ◽  
pp. 218
Author(s):  
Y. M. Toishibekov ◽  
H. D. Blackburn
Keyword(s):  
Ethylene Glycol ◽  
Liquid Nitrogen ◽  
Toxic Elements ◽  
Developmental Competence ◽  
Alternative Methods ◽  
Crystal Formation ◽  
Ice Crystal ◽  
Heat Transmission ◽  
Bovine Semen ◽  
Loop Volume

The aim of this work was to establish alternative methods for sheep morulae cryopreservation by using vitrification by open pulled straw (OPS) methods and super-cooling ultra-rapid vitrification (SCURV). Both treatments used a vitrification solution (VS) of 20% (3.6 mol L-1) ethylene glycol (EG), 20% (2.4 mol L-1) dimethylsulfoxide (DMSO), 0.5 mol L-1 sucrose in DPBS with 10% BSA in both methods. In our experiment we used the Vit-Master™ (MTG, Germany). The super-cooled LN facilitates heat transmission between LN and the cryosolution interface, and this is efficient for bovine semen and blastocyst cryoconservation (Arav et al. 2002). By surgical flushing of 24 super stimulated ewes 121 transferrable morulae were harvested; 30 morulae were transferred fresh to synchronised recipients and the others were cryopreserved by OPS (n = 49) or SCURV (n = 42), respectively thawed or warmed, and transferred to recipients. Embryos were vitrified using the OPS method. They were first incubated in 50% VS for 2 min and then transferred for 30 s into 100% VS. Each embryo was loaded by touching a 1-μL drop with the straw, which was immediately submerged into and stored in liquid nitrogen. Warming was done by placing the narrow end of the straw into DPBS + 0.25M sucrose for 5 min. Embryos were then transferred into DPBS + 0.125 M sucrose for 3 min and finally to DPBS until transfer. The SCURV morulae were then exposed to 50 and 100% VS at 37°C for 2 min and 30 s, respectively. Embryos after saturation VS have been transferred by on a surface of a nylon loop (volume 20 μL, diameter 0.5 mm) and using negative pressure temperature of liquid nitrogen in the chamber for freezing with the VIT-Master. Thawing vitrified embryos was accomplished by placing the vitrified embryos in solutions of sucrose 0.25 and 0.125 with expositions of 2 and 3 min, accordingly. After embryos were thawed, only good quality embryos were transferred. Importantly, our data suggest that by using the SCURV method, the toxic elements contained in the cryopreservation solution can be reduced while maintaining a similar ability to produce viable morulae for implantation as the OPS method. Although further work on the developmental competence of embryos cryopreserved with the SCURV method are needed, these data suggest that the faster freeze rate and lower levels of cryoprotectants of SCURV are able to minimize ice crystal formation and should be further evaluated as a routine mechanism for cryopreserving sheep morulae. Table 1.Effect vitrification and ultra-rapid super-cooling vitrification on the viability and lambing of sheep morulae

45 EFFECT OF VITRIFICATION ON KIDDING OF CAPRINE EMBRYOS

2014 ◽  
Vol 26 (1) ◽  
pp. 136
Author(s):  
M. M. Toishibekov ◽  
H. Blackburn ◽  
G. A. Valieva ◽  
S. M. Askarov ◽  
B. B. Molzhigitov
Keyword(s):  
Survival Rate ◽  
Ethylene Glycol ◽  
Statistical Difference ◽  
Developmental Competence ◽  
Crystal Formation ◽  
Ice Crystal ◽  
Heat Transmission ◽  
Bovine Semen ◽  
Fresh Frozen ◽  
Fresh Embryos

This work evaluated different methods: vitrification (V) and super-cooling ultra-rapid vitrification (SCURV). The goat morulae were cryopreserved into the High Security Vitrification (HSV) Kit (Cryo Bio System, Paris, France). The vitrification method was applied according to the method described by Vajta et al. (1998). Both treatments used a vitrification solution [VS; 20% (3.6 mol L–1) ethylene glycol (EG), 20% (2.4 mol L–1) dimethyl sulfoxide (Me2SO), and 0.5 mol L–1 of sucrose in Dulbecco's PBS (DPBS) with 10% BSA in both methods]. In our experiment, we used the Vit-Master™ apparatus (MTG GmbH, Bruckberg, Germany). The supercooled LN facilitates heat transmission between LN and the cryosolution interface and this is efficient for bovine semen and blastocyst cryoconservation (Arav et al. 2002). By surgical flushing of 30 superstimulated (1200 IU of Folligon, Intervet International, Boxmeer, the Netherlands) goats, 137 transferable morulae were harvested; 41 morulae were transferred fresh to synchronized recipients (control) and the others were cryopreserved by V (n = 47) or SCURV (n = 49), respectively thawed or warmed, and transferred to recipients. Embryos were vitrified using the HSV Kit. They were first incubated in 50% VS for 2 min and then transferred for 30 s into 100% VS. Each embryo was loaded by HSV Kit, which was immediately submerged into and stored in LN. Warming was done by placing the narrow end of the straw into DPBS + 0.25 M sucrose for 5 min. Embryos were then transferred into DPBS + 0.125 M sucrose for 3 min and finally to DPBS until transfer. The SCURV morulae were then exposed to 50 and 100% VS at 37°C for 2 min and 30 s, respectively. Embryos after saturation in VS were transferred by HSV Kit and using negative pressure of LN in the chamber for freezing with the VIT-Master. Thawing vitrified embryos was accomplished by placing the vitrified embryos in solutions of sucrose 0.25 and 0.125 M, with exposures of 2 and 3 min, accordingly. After thawing embryos, only good-quality embryos were transferred. The kidding rate following transfer of fresh, frozen-thawed vitrification, and SCURV methods were 25, 17, and 19 kids, respectively. No statistical difference was found for the percentage of does kidding following transfer of thawed embryos after vitrification (36.2 ± 4.4%a) and SCURV methods (38.7 ± 6.5%b). The survival rate following transfer of fresh embryos (60.9 ± 5.3c) was higher and in line with previous findings using VS. Differences were statistically significant (ac, bc: P < 0.05). Importantly, our data suggest that the SCURV method can be used for cryopreservation of goat morulae as the vitrification method. Although further work on the developmental competence of embryos cryopreserved with the SCURV method are needed, these data suggest that with SCURV, a faster freeze rate and lower level of cryoprotectants is able to minimize ice crystal formation and should be further evaluated as a routine mechanism for cryopreserving goat embryos.

155 EFFECT OF VITRIFICATION OF MORULAE ON PREGNANCY RATE IN GOAT

2015 ◽  
Vol 27 (1) ◽  
pp. 168
Author(s):  
M. M. Toishibekov ◽  
G. A. Valieva ◽  
S. M. Askarov
Keyword(s):  
Liquid Nitrogen ◽  
Statistical Difference ◽  
Developmental Competence ◽  
Alternative Methods ◽  
Heat Transmission ◽  
Group V ◽  
Bovine Semen ◽  
Student’S T ◽  
Student’S T Test ◽  
Fresh Embryos

This work evaluated alternative methods for goat morulae cryopreservation by using the High Security Vitrification Kit (Cryobiosystem): vitrification (V) and super-cooling ultra-rapid vitrification (SCURV). Vitrification was applied according to the method described by Vajta et al. (1998). Both treatments used a vitrification solution (VS) containing 20% ethylene glycol (EG), 20% dimethylsulfoxide (Me2SO), 0.5 mol L–1 sucrose in DPBS with 10% BSA. In our experiment we used the Vit-Master™ (MTG, Germany). Super-cooled liquid nitrogen (LN) facilitates heat transmission between LN and the cryosolution interface suggested to be beneficial for bovine semen and blastocyst cryoconservation. By surgical flushing of 30 super-stimulated goats, 137 transferable morulae were harvested; 41 morulae were transferred fresh to synchronized recipients (control) and the others were cryopreserved by V (n = 47) or SCURV (n = 49), respectively thawed, and transferred to recipients. Embryos were vitrified using the HSV Kit. They were first incubated in 50% VS for 2 min and then transferred for 30 s into 100% VS followed by vitrification (group V). Accordingly, morula of SCURV group were exposed to 50% VS for 2 min and to 100% VS for 30 s at 37°C. Thereafter, embryos were transferred into the VIT-Master for freezing with liquid nitrogen using negative pressure. Thawing of vitrified embryos was accomplished by placing the vitrified embryos in solutions of 0.25 M sucrose for 2 min and 0.125 M sucrose for 3 min, respectively. After thawing only survived embryos were transferred. Statistical analyses were performed with Student's t-test. After transfer of fresh or frozen-thawed embryos of V and SCURV groups, 25, 17, and 19 kids were born. No statistical difference was found for the percentage of viability of thawed embryos after vitrification (36.2 ± 4.4%), and SCURV methods (38.7 ± 6.5%). The survival of fresh embryos, however, was significantly higher (60.9 ± 5.3%). Differences were statistically significant (P < 0.05). Importantly, our data suggest that the SCURV method can be used for cryopresevation of goat morulae. Nevertheless, further work regarding the developmental competence of embryos cryopreserved with the SCURV method is needed.

165 OVARIAN RESPONSE AND EMBRYO RECOVERY RATES OF OLD MARES TREATED WITH A LOW DOSE OF EQUINE PITUITARY EXTRACT

2010 ◽  
Vol 22 (1) ◽  
pp. 241
Author(s):  
B. F. Bonin ◽  
J. A. Dellaqua Jr ◽  
M. A. Alvarenga
Keyword(s):  
Ovarian Response ◽  
Pituitary Extract ◽  
Embryo Viability ◽  
Daily Growth ◽  
Recovery Rates ◽  
Embryo Recovery ◽  
The Mean ◽  
Student’S T ◽  
Fresh Semen ◽  
Student’S T Test

Mares older than 15 years have low embryo recovery rates, mostly because of disturbances in follicle or oocyte maturation and early embryonic development. A recent publication showed that circulating LH level is lower in older mares (Ginther et al. 2009 Theriogenology 5, 780-788). Equine pituitary extract (EPE) is rich in LH and consequently is able to increase circulating LH levels after injection into mares. The present study aimed to evaluate the effect of low doses of EPE on follicular growth, ovulation rate, and embryo recovery rates in older mares. Embryo donors (n = 20) were Quarter Horses from a commercial embryo center that ranged in age from 15 to 20 years. Donors were used during 3 consecutive cycles. The first and third cycles were used as control cycles, and the EPE treatment was performed on the second cycle. During estrus in each of the 3 cycles, mares were inseminated with cooled or fresh semen from the same stallion and received an injection of deslorelin (1 mg i.m.) upon detection of at least 1 follicle of 35 to 40 mm in diameter. Embryo flushes were performed on Day 8 post-ovulation and were followed by administration of prostaglandin. On the treated cycle, EPE injections (7 mg twice daily i.m.) were started on Day 8 after ovulation until a preovulatory follicle was observed. The percentage of mares with more than one ovulation was compared using Fisher’s test. The mean number of ovulations and embryos, as well as follicular diameter, was compared using Student’s t-test. The percentage of mares with more than one ovulation as well as the number of ovulations per cycle were higher (P < 0.05) in the EPE-treated cycle (65% of mares and 1.8 ovulations, respectively) than in the control cycles before (5% and 1.0) and after treatment (5% and 1.0). Also, the mean number of embryos recovered per cycle was higher (P < 0.05) in EPE-treated cycles (1.0) than in nontreated cycles (0.42). However, the embryo recovery rate per ovulation was similar (P > 0.05) between nontreated (0.4 embryo) and treated cycles (0.6 embryo). Pregnancy rates of the transferred embryos were also similar between embryos recovered on treated (14/20; 70%) and nontreated cycles (9/17; 55%). The daily growth of the dominant follicle was not altered by the EPE treatment. However, embryos recovered during treated cycles were more advanced in development than controls, with more embryos (P < 0.05) classified as morula or early blastocysts when recoverd during nontreated (58%) v. EPE-treated cycles (0%). Based on the results of the present experiment, we can conclude that EPE treatment was able to increase the reproductive efficiency of older embryo donor mares. The improvement in embryo recovery rates on EPE-treated cycles seemed to be more related to the increase in the number of ovulations per cycle than with an improvement in embryo viability.

scholarly journals 121VITRIFICATION OF MOUSE MORULAE BY A NEW METHOD: PULLULAN FILM-STRAW VITRIFICATION

2004 ◽  
Vol 16 (2) ◽  
pp. 183 ◽  
Author(s):  
Y. Takagi ◽  
M. Shimizu ◽  
T. Kato ◽  
A. Danguri ◽  
M. Sakamoto
Keyword(s):  
Water Soluble ◽  
Field Conditions ◽  
Embryo Cryopreservation ◽  
Large Animal ◽  
Test Results ◽  
Morula Stage ◽  
Student’S T ◽  
Almost All ◽  
Cryopreservation Method ◽  
Student’S T Test

Recent technical improvements have resulted in higher cryosurvival of oocytes and embryos of various species. However, almost all methods require thawing and washing the embryos under microscopic observation and, therefore, cannot be conveniently used for large animal ET in the field. The purpose of the present work was to develop a new embryo cryopreservation method using a water-soluble film made of pullulan (Hayashibara, Okayama, Japan) that might, in the future, be readily adaptable to field conditions. Morula-stage mouse embryos were collected from superovulated ICR donors 72h after hCG injection. Embryos were first exposed to 10% DMSO+10% ethylene glycol (EG) in DPBS+20% FCS (mPBS) for 2min, and then equilibrated for 30s in a vitrification solution composed of 20% DMSO+20% EG+0.6M sucrose in mPBS. In the pullulan film-straw vitrification method, the embryos were loaded onto the pullulan film (20μm thick, 5mm long and 1mm wide) and were directly plunged into LN2. The pullulan film was inserted into a pre-frozen 0.25mL plastic straw (&lt;−150°C) containing 0.15mL mPBS and sealed with a plastic screw cap. For thawing, the medium in the straw was rapidly warmed in 37°C water while the pullulan film remained frozen by placing the top of the straw in contact with a cold iron block (&lt;−150°C). As soon as the medium thawed, the pullulan film was immersed in the medium by a rapid downward swinging of the straw. Five min later, embryos were recovered from the straw and washed for 2min in mPBS, for 2min in 0.1% BSA-PBS and for 2min in KSOM sequentially, and then cultured at 37°C in 5% CO2 for 38h. Noncryopreserved embryos and embryos cryopreserved by the cryoloop method (Lane et al., 1999 Nat. Biotech. 17, 1234) served as controls. Data were analyzed by χ2 test and Student’s t-test. Results are shown in Table 1. There are no significant differences (P&gt;0.05) in either developmental abilities or cell numbers between vitrified and non-vitrified embryos. This study demonstrates that mouse morulae can be successfully vitrified and thawed by the PFSV method. This method may eventually be applied to bovine ET under field conditions. Table 1 Development of mouse morulae in culture following vitrification by the PFSV method

High-pressure freezing and freeze substitution of plant tissue

1992 ◽  
Vol 50 (1) ◽  
pp. 748-749
Author(s):  
William P. Sharp ◽  
Robert W. Roberson
Keyword(s):  
High Pressure ◽  
Cell Structure ◽  
Leaf Tissue ◽  
Freeze Substitution ◽  
Crystal Formation ◽  
Ice Crystal ◽  
High Pressure Freezing ◽  
Cell Components ◽  
Cold Metal ◽  
Brome Grass

The aim of ultrastructural investigation is to analyze cell architecture and relate a functional role(s) to cell components. It is known that aqueous chemical fixation requires seconds to minutes to penetrate and stabilize cell structure which may result in structural artifacts. The use of ultralow temperatures to fix and prepare specimens, however, leads to a much improved preservation of the cell’s living state. A critical limitation of conventional cryofixation methods (i.e., propane-jet freezing, cold-metal slamming, plunge-freezing) is that only a 10 to 40 μm thick surface layer of cells can be frozen without distorting ice crystal formation. This problem can be allayed by freezing samples under about 2100 bar of hydrostatic pressure which suppresses the formation of ice nuclei and their rate of growth. Thus, 0.6 mm thick samples with a total volume of 1 mm3 can be frozen without ice crystal damage. The purpose of this study is to describe the cellular details and identify potential artifacts in root tissue of barley (Hordeum vulgari L.) and leaf tissue of brome grass (Bromus mollis L.) fixed and prepared by high-pressure freezing (HPF) and freeze substitution (FS) techniques.

The “KIMWIPE” Effect in Ultra-Thin Cryosections

1985 ◽  
Vol 43 ◽  
pp. 458-459
Author(s):  
I. Taylor ◽  
P. Ingram ◽  
J.R. Sommer
Keyword(s):  
Skeletal Muscle ◽  
Electrical Stimulation ◽  
Muscle Fibers ◽  
Ice Crystals ◽  
Crystal Formation ◽  
Ice Crystal ◽  
Thin Sections ◽  
Skeletal Muscle Fibers ◽  
Freeze Dried ◽  
Ice Crystal Formation

In studying quick-frozen single intact skeletal muscle fibers for structural and microchemical alterations that occur milliseconds, and fractions thereof, after electrical stimulation, we have developed a method to compare, directly, ice crystal formation in freeze-substituted thin sections adjacent to all, and beneath the last, freeze-dried cryosections. We have observed images in the cryosections that to our knowledge have not been published heretofore (Figs.1-4). The main features are that isolated, sometimes large regions of the sections appear hazy and have much less contrast than adjacent regions. Sometimes within the hazy regions there are smaller areas that appear crinkled and have much more contrast. We have also observed that while the hazy areas remain still, the regions of higher contrast visibly contract in the beam, often causing tears in the sections that are clearly not caused by ice crystals (Fig.3, arrows).

Serosal and cutaneous recordings of gastric myoelectrical activity in patients with gastroparesis

1994 ◽  
Vol 266 (1) ◽  
pp. G90-G98 ◽  
Author(s):  
J. D. Chen ◽  
B. D. Schirmer ◽  
R. W. McCallum
Keyword(s):  
Electrical Stimulation ◽  
Slow Wave ◽  
Test Meal ◽  
Frequency Change ◽  
Fasting State ◽  
Gastric Myoelectrical Activity ◽  
Myoelectrical Activity ◽  
Gastric Slow Wave ◽  
Student’S T ◽  
Student’S T Test

The aims of this study were to 1) investigate gastric myoelectrical activity in patients with gastroparesis, 2) validate the cutaneous electrogastrogram (EGG) in tracking the frequency change of the gastric slow wave, and 3) investigate the effect of electrical stimulation on gastric myoelectrical activity. Gastric myoelectrical activity was recorded in 12 patients with documented gastroparesis using serosal electrodes for > 200 min in each subject. All recordings were made at least 4 days after surgery. Each session consisted of a 30-min recording in the fasting state and a 30-min recording after a test meal. The test meal (liquid or mixed) was selected according to patient's tolerance. Electrical stimulation was performed in three subjects via the serosal electrodes at a frequency of 3 cycles/min. Gastric myoelectrical activity was recorded using serosal electrodes in each session. The serosal recording showed slow waves of 2.5 to 4.0 cycles/min in all 12 subjects. Absence of spikes was noted in 11 of the 12 subjects. The simultaneous serosal and cutaneous recording of gastric myoelectrical activity showed that the frequency of the EGG was exactly the same as that of the serosal recording. Liquid meals resulted in a significant decrease in slow-wave frequency (Student's t test, P = 0.006), and the EGG accurately reflected this change. Electrical stimulation had no effect on the frequency of the gastric slow wave and did not induce spikes.(ABSTRACT TRUNCATED AT 250 WORDS)

The Effect of Changes in Dialysate Volume on Glucose and Urea Equilibration

1994 ◽  
Vol 14 (3) ◽  
pp. 236-239 ◽  
Author(s):  
Edward C. Kohaut ◽  
F. Bryson Waldo ◽  
Mark R. Benfield
Keyword(s):  
Renal Failure ◽  
Chronic Renal Failure ◽  
Prospective Study ◽  
Body Surface ◽  
Patient Population ◽  
Different Ages ◽  
Student’S T ◽  
A Prospective Study ◽  
Dialysate Volume ◽  
Student’S T Test

Objectives To determine the effect of changing dialysate volume on urea and glucoseequilibration curves and to determine, if dialysate volume is prescribed on the basis of body surface area, whether equilibration curves will be consistent in patients of different sizes and ages. Design A prospective study wherein children with acute or chronic renal failure had peritoneal equilibration studies done with dwell volumes of 30 mL/kg, 40 mL/kg, and 1200 mL/m2. Patient Population Twenty-two children: 7 under 3 years of age; 8 between 3 and 10 years of age; 7 older than 10 years of age. Statistics Student's t-test. Results Urea and glucose equilibrated rapidly at dwell volumes of 30 mL/kg, slower at dwell volumes of 40 mL/kg, and slowest at dwell volumes of 1200 mL/m2. Equilibration curves were similar in children of different ages when dialysate volumes of 1200 mL/m2 were infused. Conclusion Dialysate volumes of 1200 mL/m2 should be used when equilibration studies are being done to compare individuals of different ages and sizes.

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