Biomedical subjects

E Kawakami

Publications and source records attributed to E Kawakami.

At least 37 records · Page 2Linked to original sources

PubMed2000

Azoospermia of dogs with apoptotic germ cells and Leydig cells.

Apoptotic cell death in the testes of 4 dogs with azoospermia was examined. Blood plasma luteinizing hormone (LH), testosterone (T), and estradiol-17beta (E2) concentrations, and testicular transferrin (Tf) concentration as a marker of Sertoli cell function were measured in the 4 azoospermic dogs and in 5 normal dogs. The spermatids in 2 of the 4 azoospermic dogs and the Leydig cells in 3 of them exhibited apoptotic cell death. Mean LH, E2, and Tf concentrations in the 4 azoospermic dogs were significantly higher than in the normal dogs (P<0.01). These findings suggested that the azoospermia in all 4 dogs might has been caused by abnormal functions of Sertoli cells as well as Leydig cells.

Animals↗

PubMed2000

Effects of orvus ES paste on canine spermatozoal longevity after freezing and thawing.

Because of weak resistance of canine sperm to freezing, an applicable method of preparing canine frozen semen has not yet been established. We added various concentrations of Orvus ES Paste (OEP) to egg yolk Tris-fructose citrate, and investigated its effectiveness on survival of spermatozoa. Addition of 0.5-1.0% OEP to the extender for freezing canine semen was effective in prolonging post-thaw survival of spermatozoa.

Animals↗

PubMed2000

Effect of addition of Orvus ES paste to frozen canine semen extender on sperm acrosomes.

Using the triple-stain technique, we investigated whether sperm acrosomes in frozen canine semen were protected during freezing and thawing by addition of a surfactant, Orvus ES Paste (OEP), to the extender. Acrosomes were clearly shown to be protected by the addition of OEP to the entender when compared with those in sperm frozen without OEP addition (p<0.05).

Acrosome↗

PubMed2000

Intrauterine and intravaginal insemination with frozen canine semen using an extender consisting of orvus ES paste-supplemented egg yolk tris-fructose citrate.

Our previous report indicated that addition of Orvus ES Paste (OEP) to the extender of frozen canine semen protected acrosomes and maintained sperm motility after thawing. In this study, artificial insemination (AI) using the frozen semen was carried out. The frozen semen was prepared using egg yolk Tris-fructose citrate, and the final concentrations of glycerol and OEP were 7% (v/v) and 0.75% (v/v), respectively. AI was performed during the optimal mating period predicted from the peripheral plasma progesterone level. In intrauterine insemination (IUI), the bitches were laparotomized and 1 x 10(8) spermatozoa were infused into one of the uterine horns. In insemination of non-OEP supplemented semen, 3 x 10(8) spermatozoa were inseminated. In intravaginal insemination (IVI), 10-40 x 10(8) spermatozoa were inseminated. Conception was obtained in nine of 10 bitches (90.0%) that underwent IUI. The number of newborns was from 1 to 7 (mean 3.6 +/- 0.9). The mean ratio of the number of puppies to the number of ovulations in the inseminated uterine horn was 71.8%. The number of puppies did not exceed the number of ovulation in the inseminated uterine horn. Conception using non-OEP supplemented frozen semen was unsuccessful in all four bitches. In IVI, conception was not obtained in any of the six bitches that received insemination of 10 x 10(8) or 40 x 10(8) spermatozoa, but two of three bitches that received insemination of 20 x 10(8) spermatozoa were fertilized. It was shown that a high conception rate can be obtained by IUI using OEP-supplemented frozen canine semen. Developmenmt of a non-surgical method of IUI and a method of freezing canine sperm applicable to IVI is necessary.

Animals↗

PubMed2000

Induction of dog sperm capacitation by glycosaminoglycans and glycosaminoglycan amounts of oviductal and uterine fluids in bitches.

Ejaculated sperm collected from 12 beagle dogs were incubated in canine capacitation medium (CCM), supplemented with 5 microg/ml chondroitin sulfate A (CS), 5 microg/ml hyaluronic acid (HA), or 5 microg/ml heparin (HP) for 7 hr at 38 degrees C in a 5% CO2 in air atmosphere to investigate the effects of glycosaminoglycans (GAGs) on dog sperm capacitation. The percentages of motile sperm, hyperactivated sperm (%HY), and acrosome-reacted sperm (%AR) in all media were examined after 4 hr and 7 hr of incubation. The oviducts and uteri of 9 anestrous and 18 estrous beagle bitches were removed under halothane inhalation anesthesia to measure the total GAG amounts in oviductal and uterine fluids. The lumens of the ampulla of the oviducts, isthmus of the oviducts, and the uterine horns were each flushed with 1 ml HEPES-EDTA fluid. Total GAG amounts in the flush fluids obtained were measured with a spectrophotometer. Sperm motility (51-59%), %HY (79-86%), and %AR (31-36%) in CCM supplemented with CS, HA, or HP were significantly higher after 7 hr of incubation than when incubated in CCM without GAGs (P<0.01 or 0.05). The mean total GAG amounts in the fluids from the ampulla and isthmus of the oviducts and the uterine horns in the estrous bitches were higher than in the anestrous bitches. These results indicate that GAGs in the oviductal and uterine fluids in estrous bitches are associated with in vivo sperm capacitation.

Acrosome Reaction↗

PubMed2000

[Ciliochoroidal detachment following scleral buckling surgery for rhegmatogenous retinal detachment].

PURPOSE AND METHODS: We observed the peripheral choroid; ciliary body, and depth of the anterior chamber by ultrasound biomicroscopy (UBM) in 31 eyes with rhegmatogenous retinal detachment before and after scleral buckling surgery. Scleral encircling was performed in 11 eyes and segmental scleral buckling in 20 eyes. RESULTS: With UBM, ciliochoroidal detachment was detected in all eyes (100%) following scleral encircling and in 8 eyes (40.0%) following segmental scleral buckling. After scleral encircling procedure, the eyes with preoperatively bullous and wide retinal detachment showed a severe ciliochoroidal detachment and edema of the ciliary body. Shallowing of the anterior camber occurred in all 11 eyes (100%) after scleral encircling and in 12 of 20 eyes (60.0%) after segmental scleral buckling. Marked shallowing with closure of the angle and elevated intraocular pressure occurred in 2 eyes. CONCLUSION: The results showed that careful postoperative examinations for the anterior segments, chamber angle, and intraocular pressure are necessary with slit-lamp examination and applanation tonometry after scleral buckling surgery.

Adult↗

PubMed1999

Effects of medium containing heparin and theophylline on capacitation and metabolic enzyme activities of ejaculated spermatozoa from dogs with asthenozoospermia.

The percentages of motile sperm (%MO), hyperactivated sperm (%HA), and acrosome-reacted sperm (%AR) of four beagle dogs with asthenozoospermia (AS) and five normal beagle dogs were determined during 7 h of incubation. The metabolic enzyme activities of the sperm was examined after 0 and 4 h of incubation. The sperm were incubated in canine capacitation medium (CCM) and CCM containing either 20 microg ml(-1) heparin (HE), 10 microg ml(-1) theophylline (TH) or 20 microg ml(-1) HE + 10 microg ml(-1) TH in glass tubes at 38 degrees C under 5% CO2 in air. The %HA and %AR were determined by counting the sperm exhibiting star-spin like movement and by the triple stain technique. The spermatozoa in HE + TH CCM were homogenized and centrifuged, and the metabolic activities of hexokinase, fructokinase, glucose-6-phosphodehydrogenase (G6PD), and pyruvate kinase in the sperm cytosol in the supernatant was measured with a spectrophotometer. The mean %MO and %HA values of both AS and normal dogs in the four types of CCM were highest in HE + TH CCM, with a mean %HA in HE + TH CCM of 78 +/- 5% (S.E.) after 7 h of incubation. However, there was little difference in %AR among the four types of CCM. The mean activities of the four enzymes in the sperm of AS dogs before incubation was significantly lower than in the sperm of normal dogs (P < 0.05, 0.01). However, after 4 h of incubation the activities of all enzymes in the sperm of both AS and normal dogs was clearly higher in HE + TH CCM than in the control CCM. These findings indicate that HE and TH in the medium are effective inactivating metabolic enzymes, maintaining longer sperm motility, and efficiently inducing HA even of the sperm of AS dogs.

Acrosome Reaction↗

PubMed1999

Pursuit of the origin of the large myelinated fibers of the anterolateral funiculus in the spinal cord in humans in relation to the pathomechanism in amyotrophic lateral sclerosis.

To determine the origin of the large myelinated fibers in the anterolateral funiculus (ALF) in the spinal cord of humans, myelinated fibers in the ALF of the mid-cervical spinal cord were examined quantitatively. Five groups of subjects were examined, consisting of control subjects, patients with cerebral lesions and showing complete degeneration of the unilateral/bilateral pyramis of the medulla oblongata, those with lesions of the pontine tegmentum, those with lesions of the lower cervical spinal cord, and those with thoracic/lumbar lesions. The results indicate that the large myelinated fibers in the ALF of the mid-cervical spinal cord of humans originate from the tegmentum of the brain stem and the lower cervical spinal cord, and not from the cerebrum, or the thoracic or lumbar spinal cord. Thus, they are descending fibers from the brain stem tegmentum and ascending fibers from the lower cervical cord, and not corticospinal tracts or long-ascending fibers from the thoracic or lumbar spinal cord. The origin of the large myelinated fibers in the ALF of the spinal cord in humans, the number of which was severely decreased in patients with amyotrophic lateral sclerosis, is considered to be the long-descending neurons in the brain stem tegmentum and the propriospinal neurons in the spinal cord.

Adult↗

PubMed1999

Changes in testicular transferrin concentrations measured by enzyme immunoassay after FSH administration to beagle dogs.

A sensitive enzyme immunoassay (EIA) was developed for transferrin (Tf) in the canine testis, as an effective marker of Sertoli cell function. Tf was purified from male dog serum by DEAE-Affi-Gel Blue chromatography and gel filtration. Rabbits were immunized with the Tf, and anti-dog Tf antibody was purified from the rabbit serum by affinity chromatography as primary antibody for EIA. Peroxidase-conjugated goat anti-dog Tf antibody was used as the secondary antibody for microtitre plate double-antibody EIA. The EIA was applied to measurement of testicular Tf concentrations in five normal beagle dogs. All of the dogs were given five injections of 2 mg porcine pituitary FSH at 12 h intervals, and testicular biopsy was performed. The testicular tissue was used for EIA of Tf. The optimum dilutions of the primary and secondary antibodies for the standard curves of canine Tf were 1: 4000 and 1: 1000, respectively. The limits of sensitivity of our EIA were between 30 ng Tf/plate-well and 2500 ng/well. The intra- and inter-assay coefficients of variation, and the recovery rate were 8.6, 7.6 and 86.0%, respectively. Before FSH administration, the mean +/- SEM Tf concentration in the testis of normal dogs was 357 +/- 31 ng/mL. At 12 h after the final FSH administration, Tf concentrations were significantly increased (p < 0.5) when compared with values before the start of treatment. Thus, Tf in the canine testis, measured by our EIA, appears capable of serving as a marker of Sertoli cell function.

Animals↗

PubMed1999

Function of contralateral testis after artificial unilateral cryptorchidism in dogs.

The effects of a cryptorchid testis on the contralateral testis were investigated after artificially producing unilateral cryptorchidism in 8 beagle dogs. Bilateral testicular biopsy and collection of spermatic vein blood and peripheral vein blood were performed at the time of the operation to produce the cryptorchidism and 52 weeks later. The testicular tissue was used for histological examination by light microscopy and measurement of the testicular transferrin (Tf) concentration by enzyme immunoassay. Plasma testosterone (T), estradiol-17 beta (E2), and luteinizing hormone (LH) levels were measured by radioimmunoassay. Semen was collected weekly and its quality was examined. No spermatogenesis was observed in the cryptorchid testes at 52 weeks after the operation, and the number of germ cells in the contralateral testes had decreased but the number of Sertoli cells did not change. The Tf concentration in both testes had also decreased. The mean total number of sperm between 48 and 52 weeks after the operation (194 x 10(6)) was less than half the number before the operation (510 x 10(6)). Mean spermatic vein plasma T levels (51 ng/ml) in the cryptorchid testes 52 weeks after the cryptorchid operation were significantly lower than before the operation (91 ng/ml; P < 0.05). By contrast, spermatic vein plasma E2 levels (80 pg/ml) were significantly higher than the values before the operation (51 pg/ml P < 0.05). The peripheral plasma LH levels decreased. These findings indicate that a large quantity of E2 secreted by the cryptorchid testis inhibits the endocrine and spermatogenic functions of the contralateral testis in the dog. In particular, it is assumed that dysfunction of the contralateral testis is associated with Sertoli cell dysfunction suggested by the low Tf concentration.

Animals↗

PubMed1999

Changes in hyaluronidase, acrosin, and N-acetylhexosaminidase activities of dog sperm after incubation.

Hyaluronidase, acrosin and N-acetylhexosaminidase activities were examined in sperm collected from 12 beagle dogs and in culture medium after 0.5 hr and 7 hr of sperm incubation. The activities of the three enzymes were significantly higher at 7 hr than at 0.5 hr (P < 0.05, 0.01), and the increases were associated with sperm capacitation. It was considered that the three enzymes in the dog sperm are related to fertilization by reason of the findings of the release of these enzymes from the sperm into the medium after 7 hr of incubation.

Acrosin↗

PubMed1999

[Application of measuring 99mTc-MAG3 plasma clearance based on one-compartment model (MPC method) to renal transplantation].

Measurement of 99mTc-MAG3 plasma clearance (CLmag) based on one-compartment model (MPC method) was applied to renal transplantation and evaluated for the factors which might affect the calculated results, especially concerning renal depth. Correlation coefficient of CLmag between MPC method using real renal depth and Russell or Bubeck single sampling method was good (r = 0.852 or 0.876, respectively). Regression equation between MPC method and Russell method was y = 1.044x - 3.0 and was more closer to y = x than that between MPC method and Bubeck method. CLmag of MPC method calculated by estimated renal depth from the abdominal thickness was also similar to that by real renal depth. Even if the fixed renal depth, 4 cm, was applied, the coefficient and regression equation between MPC method and Russell method were r = 0.884 and y = 1.004x - 10.2. In conclusion, MPC method is applicable to the evaluation of renal transplants. Though measuring renal depth is best, calculation with fixed renal depth of 4 cm might be practically acceptable.

Adult↗

PubMed1998

Comparison of glucokinase activities in the peripheral leukocytes between dogs and cats.

Activities of hexokinase (HK), glucokinase (GK) and pyruvate kinase (PK), were measured. The expression of GK mRNA was investigated using reverse transcription-polymerase chain reaction (RT-PCR) in leukocytes (WBC) of dogs and cats. No significant differences between dogs and cats were found in concentrations of blood glucose and plasma insulin. Dog WBC showed GK activities and the specific fragment with predicted size of 574 bp containing conserved region including glucose- and ATP-binding domains of GK as determined with RT-PCR. However, in cat WBC, the activities and specific fragment of GK were absent. After fasting, the activities and gene expression of GK decreased greatly in the dog WBC. The cat WBC had significantly higher activities of HK and PK than dog WBC.

Animals↗

PubMed1998

Chlormadinone acetate pellet implantation plus short-term oral administration in dogs with benign prostatic hypertrophy.

Eight beagles with benign prostatic hypertrophy (BPH) were treated by subcutaneous implantation of pellets containing 10 mg/kg chlormadinone acetate (CMA), a synthetic anti-androgen, plus daily oral administration of CMA at 2 mg/kg per day for 7 days as a therapy for BPH. Prostatic and testicular size were measured and prostatic and testicular biopsies were performed by laparotomy before and after CMA treatment. Plasma levels of luteininzing hormone (LH), testosterone and oestradiol were also measured. The clinical signs of BPH, for example haematuria and dysuria, resolved within 1 week of treatment. Mean prostatic volume decreased to 56% of the pretreatment value. At 40 weeks after treatment, prostatic volume had decreased by 36%. Histological examination of the prostate 1 week after treatment revealed reduction in diameter of the alveoli and in height of the glandular epithelium. Degeneration and atrophy of the glands were marked 4-12 weeks after treatment. In the testis, the diameter of seminiferous tubules and the number of germ cells in the seminiferous tubules had decreased markedly at 12 and 24 weeks after treatment. Although plasma LH concentrations did not undergo any marked fluctuations after CMA treatment, levels of testosterone and oestradiol were lower than before treatment. The results indicate that implantation of 10 mg/kg CMA, plus 7-day oral administration of 2 mg/kg CMA, bring about resolution of the clinical signs and marked reduction in prostatic volume within 1 week of treatment.

Administration, Oral↗

PubMed1998

Induction of dog sperm capacitation by oviductal fluid.

Four estrous beagles were inseminated with 1 x 10(8) sperm into both the right and left uterine horns, and the uterine horn and oviduct on one side were removed under anesthesia after 7 hr and 24 hr, respectively. The lumen of the uterine horns and oviducts was flushed with canine capacitation medium (CCM), and movement of the sperm in CCM was assessed by phase-contrast microscopy. In a second experiment, ejaculated sperm obtained from 5 normal beagles was incubated in CCM supplemented with oviductal flush fluid (OF-CCM) at 38 degrees C with 5% CO2 in air. Motility of sperm, and percentages of hyperactivated sperm (%HA) and acrosome-reacted sperm (%AR) among freely swimming (FS) sperm were investigated until 24 hr after the start of incubation. After 7 hr of incubation the sperm was coincubated with canine oocytes in OF-CCM for 2 hr, and the number of zona pellucida-binding (zona-binding) sperm was then counted. The %HA among the sperm in the oviductal flush fluid both 7 hr (mean +/- S.E.; 15.0 +/- 2.4%) and 24 hr (77.5 +/- 5.2%) after intrauterine insemination were significantly higher than in the uterine flush fluid (P < 0.05, 0.01, respectively). The motility and %HA among FS-sperm in OF-CCM were higher than in the control medium without oviductal fluid. However, there was no difference in the %AR between OF-CCM and control medium. The number of zona-binding sperm in OF-CCM (8 +/- 1) was significantly greater than in control medium (5 +/- 1) (P < 0.05). These results suggest that oviductal fluid in the estrous bitch maintains sperm motility and induces sperm capacitation.

Anestrus↗

PubMed1998

Changes in semen quality and in vitro sperm capacitation during various frequencies of semen collection in dogs with both asthenozoospermia and teratozoospermia.

Eight male dogs with both asthenozoospermia and teratozoospermia were used in this study. In experiment 1, semen was collected 10 times at intervals of 48 hr, 24 hr and 12 hr in 4 of the 8 dogs, and the semen quality was evaluated. In experiment 2, semen was collected 5 times at 24-hr intervals in the other 4 dogs. The spermatozoa collected on day 1 and day 5 were incubated for 4-6 hr in Canine Capacitation Medium, and the percentages of hyperactivated sperm (%HA), acrosome-reacted sperm (%AR), and the zona pellucida-binding sperm count (ZP sperm count) were assessed. The results of experiment 1 showed that the percentage of motile sperm increased and the percentage of abnormal sperm decreased markedly as the intervals between semen collections became shorter. When semen was collected at 12-hr intervals, the percentage of motile sperm increased from about 65%, the value before frequent collection was started, to about 80%, and the percentage of sperm with abnormal tails decreased from 30% to 15%. In experiment 2, the percentages of HA and AR, and the ZP sperm count in specimens collected on day 5 were higher than those in specimens collected on day 1, and the differences in % HA and in ZP sperm count were significant (P<0.05). The results demonstrated that sperm motility, abnormality, and potential fertility in dogs with asthenozoospermia and teratozoospermia can be temporarily improved by frequent semen collection.

Acrosome↗

PubMed1998

Changes in plasma LH and testosterone levels and semen quality after a single injection of hCG in two dogs with spermatogenic dysfunction.

Plasma LH and testosterone (T) levels and semen quality after a single intramuscular injection of 1,000 IU hCG were investigated in a Beagle dog with azoospermia and a Beagle dog with poor semen quality. The plasma LH levels of both dogs did not change after the treatment. Although the plasma T levels of the dog with azoospermia increased temporarily, no sperm were detected in its semen. In the dog with poor semen quality high levels of plasma T were maintained for 2 weeks after hCG treatment and its semen quality was temporarily improved between 3 and 4 weeks after treatment. These findings indicate that the semen quality of dogs with oligozoospermia can be temporarily improved after a single injection of hCG.

Animals↗

PubMed1997

Changes in plasma luteinizing hormone, testosterone and estradiol-17 beta levels and semen quality after injections of gonadotropin releasing hormone agonist and human chorionic gonadotropin in three dogs with oligozoospermia and two dogs with azoospermia.

Plasma luteinizing hormone (LH) and testosterone (T) levels in three normal male Beagles increased markedly, the LH levels peaking at 30 or 45 min and the T levels at 45 or 60 min respectively, after a subcutaneous injection of 1 microgram kg-1 gonadotropin releasing hormone agonist (GnRH-A). Two Collies and a Great dane diagnosed as oligozoospermic and two Shetland sheep dogs diagnosed as azoospermic by evaluation of semen quality were treated with 1 microgram kg-1 GnRH-A after blood collection. Their plasma levels of LH, T and estradiol-17 beta (E2) were measured by radioimmunoassay for the purpose of investigating the effect of hormone therapy on spermatogenic dysfunction and the mechanism on improvement of semen quality. The semen quality of one of the Collies had improved 4 weeks after the GnRH-A treatment. The dog was treated with GnRH-A again and mated with a bitch 4 days later. The bitch gave birth to five puppies. The other dogs, whose semen quality had not improved, were treated with an intramuscular injection of 500 or 1000 IU human chorionic gonadotrphin (hCG) per animal. Since the semen quality of the other Collie and the Great Dane improved temporarily 2 and 4 weeks, respectively, after hCG treatment, the former was mated with a bitch 5 days later. The bitch gave birth to a litter of seven puppies. These hormone treatments, however, had no effect on the azoospermia in the two Shetland sheep dogs. Although the mean plasma LH and T levels in the dogs with oligozoospermia had been low, their LH levels gradually increased after hormone treatment. There were no marked changes in plasma T or E2 levels. These findings indicate that the semen quality of dogs with oligozoospermia can be temporarily improved between 2 and 4 weeks after a single injection of GnRH-A or hCG and the fertility of the dogs restored by the injection.

Animals↗