Is Common Trunk Anomaly Frequent in Hemifacial Spasm? Comparison with Normal Subjects using MRI

PURPOSE

Hemifacial spasm (HFS) results from vascular compression at the root exit of the facial nerve. Although the underlying etiology has yet to be identified, it has been suggested that congenital vascular anomalies are involved. We have hypothesized common trunk anomaly of the anterior inferior cerebellar artery (AICA) and posterior inferior cerebellar artery (PICA), may play a role in HFS. However, no previous studies have directly compared the incidence of this anomaly between HFS patients and normal subjects. The present study was designed to address this gap in the literature.

METHODS

This case-control study compared magnetic resonance angiography data from 65 HFS patients and 65 normal subjects. Dominant AICA/PICA is defined as the absence of PICA/AICA, with the remaining AICA/PICA supplying both vascular territories. The term "common trunk" encompasses both dominant AICA and dominant PICA. The frequency of common trunk and dominant AICA/PICA was compared between the two groups.

RESULTS

There were no significant differences in the incidence of a common trunk (68.5% and 64.6%), dominant AICA (30.8% and 32.3%) and dominant PICA (37.7% and 32.3%) between the two groups. Additionally, no differences were found in the frequency of atherosclerosis risk factors.

CONCLUSIONS

There was no apparent association between common trunk anomaly and HFS. It is suspected that some vascular anomalies other than a common trunk are involved in HFS.

Deep Brain Stimulation Leads to Long-term Improvement of Neuropathic Tremor due to Chronic Inflammatory Demyelinating Polyneuropathy: A Case Report

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a peripheral neuropathy caused by immune-mediated demyelination, causing tremors in 3.9%-58% of affected patients. This neuropathic tremor may persist after treatment and is known to be refractory to conventional medication. We present two cases of neuropathic tremor due to CIDP in which deep brain stimulation (DBS) over a long-term period led to marked improvement. Case 1: A 66-year-old woman presented with severe 2-3-Hz resting, postural, and kinetic tremors of both hands. The tremor was refractory to medication but improved well after bilateral VIM-DBS. However, 2 months after the procedure, the tremor worsened and was accompanied by sensory disturbance in the extremities. A diagnosis of CIDP was made, and treatment with corticosteroids and intravenous immunoglobulin achieved remission 6 months later. Although there was residual tremor after CIDP remission, it has been well controlled by DBS for the last 10 years. Case 2: A 56-year-old man presented with a 6-year history of CIDP after developing sensory dullness and tremors in the extremities. The CIDP had gone into remission 1 year previously and the sensory deficits had improved, but the tremors had gradually worsened: severe 8-12-Hz postural, kinetic, and resting tremors were present in both upper extremities. Right VIM-DBS was performed and the tremors on the left side showed marked improvement. Over the next 8 years, the tremors were well controlled and there were no relapses of CIDP. DBS may achieve long-term improvement of neuropathic tremor caused by CIDP if the CIDP is in remission.

A Case of Unilateral Facial Spasm With Vulnerable Hearing Function Due to a History of Cisplatin Treatment, Resulting in Intraoperative Hearing Loss

A 51-year-old man with a history of cisplatin treatment for a right testicular tumor underwent microvascular decompression for hemifacial spasm. At an early stage in the surgical procedure, the intraoperative auditory brainstem response (ABR) was diminished despite a relatively minimally invasive approach, resulting in irreversible hearing loss. Cisplatin is known to cause dose-dependent hearing impairment primarily affecting the cochlea, but it can also induce neurotoxicity. In the present case, prior cisplatin administration may have caused fragility of the cochlear nerve as well. Patients with a history of ototoxic and neurotoxic drugs such as cisplatin require more careful manipulation and thorough intraoperative auditory monitoring during neurosurgical procedures that may affect hearing, such as those for hemifacial spasms.

[Image Diagnosis for Hemifacial Spasm]

Cisternography using heavy T2-weighted images from 3-Tesla magnetic resonance imaging(MRI)and three-dimensional time-of-flight MR angiography(3D TOF MRA)is useful for identifying conflicting vessels in primary hemifacial spasm(HFS). Cisternography provides high-signal images of the cerebrospinal fluid and low-signal images of the cranial nerves and cerebral blood vessels, whereas 3D TOF MRA provides high-signal images with only vascular information. The combination of these two methods increases the identification rate of conflicting vessels. The neurovascular conflict(NVC)site in HFS is where the facial nerve exits the brainstem. However, on MRI, the true NVC site is often more proximal than the facial nerve attachment to the brainstem. On preoperative MRI, it is important to not miss the blood vessels surrounding the proximal portion of the facial nerve. If multiple compression vessels or deep vessels are located in the supraolivary fossette, they may be missed. Coronal section imaging and multiplanar reconstruction(MPR)minimize the chances of missing a compression vessel. Preoperative MRI and CT can also provide various other information, such as volume of the cerebellum, presence of emissary veins, shape of the petrosal bone, and size of the flocculus.

Intracranial Neurofeedback Modulating Neural Activity in the Mesial Temporal Lobe During Memory Encoding: A Pilot Study

Removal of the mesial temporal lobe (MTL) is an established surgical procedure that leads to seizure freedom in patients with intractable MTL epilepsy; however, it carries the potential risk of memory damage. Neurofeedback (NF), which regulates brain function by converting brain activity into perceptible information and providing feedback, has attracted considerable attention in recent years for its potential as a novel complementary treatment for many neurological disorders. However, no research has attempted to artificially reorganize memory functions by applying NF before resective surgery to preserve memory functions. Thus, this study aimed (1) to construct a memory NF system that used intracranial electrodes to feedback neural activity on the language-dominant side of the MTL during memory encoding and (2) to verify whether neural activity and memory function in the MTL change with NF training. Two intractable epilepsy patients with implanted intracranial electrodes underwent at least five sessions of memory NF training to increase the theta power in the MTL. There was an increase in theta power and a decrease in fast beta and gamma powers in one of the patients in the late stage of memory NF sessions. NF signals were not correlated with memory function. Despite its limitations as a pilot study, to our best knowledge, this study is the first to report that intracranial NF may modulate neural activity in the MTL, which is involved in memory encoding. The findings provide important insights into the future development of NF systems for the artificial reorganization of memory functions.

Preoperative findings in relation to the usefulness of endoscopic assistance for microvascular decompression

PURPOSE

Endoscopy is known to be a useful adjunct for microvascular decompression (MVD) surgery, assisting observation in blind spots such as Meckel's cave in cases of trigeminal neuralgia (TN) and the root exit zone (REZ) in hemifacial spasm (HFS). However, few reports have discussed the usefulness of endoscopy in relation to individual patient characteristics or preoperative magnetic resonance imaging (MRI).

METHODS

We retrospectively reviewed the medical records of 109 patients (98 with HFS and 11 with TN, 85 women, median age 55 years) who had undergone endoscopically assisted MVD at our institution between 2017 and 2021. The usefulness of endoscopy in individual cases was scored by three neurosurgeons using a grading scale: 2, essential and indispensable; 1, useful and helpful; 0, not necessary. The mean value of the assigned scores was taken as an indicator of "usefulness," and endoscopy was considered to have been "useful" in cases with a score of > 1.0.

RESULTS

Endoscopic assistance was judged to have been useful in 69% of the patients. The proportion of patients evaluated as useful was significantly lower for TN (18.2%) than for HFS (74.5%). Patients with superior cerebellar artery compression had significantly lower scores than patients with other vessels. Endoscopy was considered useful in a significantly higher proportion of patients with anatomically complicated offending vessels (bifurcation or strong meandering) in the REZ detected by preoperative MRI (P < 0.005).

CONCLUSION

Endoscopy for MVD is useful for patients with HFS, especially when preoperative MRI shows bifurcation or strongly meandering vessels in the REZ.

Bilateral Low-Frequency Hearing Impairment After Microvascular Decompression Surgery

BACKGROUND

Hearing impairment is an important complication of microvascular decompression (MVD). In patients after MVD, we have occasionally noted slight to moderate hearing deterioration at low frequencies that is difficult to detect using pure tone average.

OBJECTIVE

To assess the incidence and features of low-frequency hearing impairment (LF-HI) after MVD and evaluate its associated factors.

METHODS

This single-center, retrospective observational study assessed the audiometric outcome of 270 patients who underwent MVD between January 2015 and December 2020. Preoperative and postoperative hearing levels were compared for each frequency. LF-HI was defined as a hearing deterioration of ≥15 dB at 125, 250, or 500 Hz. The incidence, symptoms, and associated factors of LF-HI were analyzed.

RESULTS

Statistical analysis of the patients overall demonstrated slight but significant decreases in the hearing level after MVD at lower frequencies on both the operative and contralateral sides. Eighty-one patients (30.0%) had LF-HI: 49 on the operative side, 24 on the contralateral side, and 8 on both sides, while pure tone average was worsened in 5 patients (1.8%). Subjective symptoms, including hearing deterioration, ear fullness, tinnitus, and dizziness, developed in 10.4% of the patients with LF-HI but improved subsequently within several weeks. "Older age" and "operative side" were associated with LF-HI.

CONCLUSION

Decreases in lower-frequency hearing levels in both the ipsilateral and contralateral (nonoperative) ears were observed after trigeminal neuralgia and hemifacial spasm surgery. LF-HI does not cause permanent symptoms but may be a noteworthy phenomenon, possibly involved in the contralateral hearing loss encountered occasionally after other types of posterior cranial fossa surgery.

PEDT-10 PHASE II TRIAL OF PATHOLOGY-BASED THREE-GROUP TREATMENT STRATIFICATION FOR PATIENTS WITH CNS GERM CELL TUMORS: A LONG-TERM FOLLOW-UP STUDY

Background

Phase II clinical trial funded by Ministry of Health, Labour and Welfare from 1995 to 2003 evaluated efficacy of pathology-based three-group treatment stratification for CNS germ cell tumors (GCTs). We here present long-term follow-up results.

Methods

Total 228 cases were registered. Germinoma was treated with carboplatin+etoposide (CARE) and extended-local irradiation, local irradiation was added for intermediate-prognosis-group, and poor-prognosis-group was treated with ifosfamide+cisplatin+etoposide (ICE) and whole-brain or craniospinal irradiation.

Results

Mean/median ages at diagnosis were 16.8/16 years and female-to-male ratio was 40-188. Registry included 123 germinomas, 76 intermediate-prognosis-group cases (including 38 germinoma with STGC), 28 poor-prognosis-group cases and 1 mature teratoma. Median 222-months follow-up was conducted, and 56 recurrences and 39 deaths were recorded. 10 and 20-year recurrence-free survival (RFS) for germinoma, intermediate and poor-prognosis-groups were 84/79%, 83/76% and 59/59%, respectively, and overall survival (OS) for each were 97/91%, 92/85% and 57/53%, respectively. Prognosis for germinoma with or without STGC was the same. Basal ganglia germinoma showed significantly shorter RFS but OS was not different from other locations. Median age at death was 24 years, and ages were significantly different depending on causes, such as disease-related (14 years on average) and complications (29 years). OS after recurrence at 5/10/20 years were 64/62/48%.Hormonal supplementation was seen in 82% for neurohypophyseal cases and antidiuretic hormone supplementation was most frequent (82%). Among available cases, 20-out-of-155 cases showed neoplastic/vascular complications, among which cavernous malformation was the most (n=9). Median period until complication presentation was 235 months, and the rate at 20 years was 11%.

Conclusions

Germinoma and intermediate-prognosis-group cases showed long-term survival for approximately 90%, while more intensive treatment would be necessitated for poor-prognosis-group. Long-term survivors often required hormonal supplementation, and increasing frequency of treatment-related complications was observed. There is no end of outpatient follow-up for CNS GCT patients.

Aspiration Surgery with Appropriate Antibiotic Treatment Yields Favorable Outcomes for Bacterial Brain Abscess

BACKGROUND

Even in the era of advanced medical treatment, brain abscess still has a high mortality rate. At our institution, brain abscess has been treated mainly using stereotactic or echo-guided aspiration followed by relatively long-term antibiotic treatment, achieving favorable outcomes. To evaluate the efficacy of our strategy involving less-invasive aspiration surgery and long-term selective antibiotic administration for brain abscess, a single-institution series of cases was investigated.

METHODS

We retrospectively reviewed and analyzed the medical records of 25 cases of brain abscess treated at Saitama Medical University Hospital between 2008 and 2021. The patients comprised 16 men and 9 women aged between 39 and 85 years (median 62 years). Neurosurgical intervention was performed for 23 (92.0%) of the patients and the remaining 2 received antibiotics alone.

RESULTS

Among the neurosurgery patients, 22 (95.7%) underwent echo-guided or stereotactic aspiration, and only 1 underwent craniotomy. Anaerobic bacteria were detected in 11 patients. In the surgical and conservative groups, the median duration of antibiotic treatment was 16 weeks and 23 weeks, respectively. Since 2014 when metronidazole first became available, it has replaced meropenem to cover anaerobic bacteria. The overall mortality rate was 4.0% and a favorable outcome (Glasgow Outcome Scale 4 or 5) was achieved in 76% of the patients. There was no surgical mortality or morbidity.

CONCLUSIONS

Most patients underwent aspiration surgery and achieved favorable outcomes. Along with antibiotic treatment for a sufficiently long period to cover anaerobes, this approach can be expected to yield good results.

[Technique of Microvascular Decompression for Hemifacial Spasm Based on Surgical Anatomy]

This article describes the anatomical approach and operative points of microvascular decompression for hemifacial spasm based on the author's personal experience with 1,000 cases. As vascular compression of the facial nerve is often quite caudal, it is necessary to ensure that the compressing arteries in this area are moved. Neither the vessels nor the prosthesis used to move them should not touch the root exit zone of the nerve(vascular transposition nerve isolation technique). It should also be emphasized that every effort should be made to avoid complications such as hearing impairment and postoperative subcutaneous spinal fluid accumulation.

Clinical retrospective study of dental implant removal: do patients who require implant removal desire implant prosthesis again?

Background

This study investigated the causes of dental implant removal due to complications, and examined whether patients who had dental implant removal desired re-implant prosthesis treatments.

Material and Methods

A retrospective case–control study was conducted on patients who had their dental implants removed. We investigated whether the removed dental implant was replaced with other implant prostheses. Age, sex, diabetes, smoking, implant site distribution, reason for implant removal, and blade and root-form implants were categorized as predictive variables. The outcome variable was desire for re-implantation or use of other prosthetic methods after implant removal. A logistic regression model was created to identify patient factors that could predict the re-implantation of dental prostheses after implant removal.

Results

A total of 215 dental implants were removed from 143 patients. The most common reason for implant removal was peri-implantitis that was identified in 165 implants. After implant removal, re-implantation was performed in 98 implants (45.6%). Bivariate analyses showed that age, diabetes, implant type, and reason for implant removal were associated with the desire for re-implanted prostheses. The multiple regression model revealed that age, implant type, and reason for implant removal were associated with an increased desire for re-implant prostheses after implant removal.

Conclusions

Re-implantation of prostheses after the removal of dental implants was desired by patients who were younger, had implants placed in the root form, and had implants removed due to prosthetic-related complications.

Key words:Dental implant removal, complications, implant prosthesis, retrospective study, re-implantation.

Beliefs of chronically ill Japanese patients that lead to intentional non-adherence to medication

OBJECTIVE

To identify factors, associated with personal beliefs, involved in intentional non-adherence to prescribed medication of Japanese patients with chronic diseases.

METHODS

A cross-sectional study of Japanese subjects with chronic, primarily liver, gastrointestinal, or nervous system diseases who had been prescribed oral medicines for regular use, was performed. The subjects were admitted to a university hospital and were interviewed face-to-face on admission. Intentional non-adherence was defined as experience of deliberate adjustment of self-managed prescription medicines during the few months prior to hospital admission. Patients' beliefs about taking medicines were assessed from the perspective of what the patient valued in order to take medicines without anxiety; whether the patient valued information about the medication such as its function and side-effects and/or mutual reliance on doctors. Using logistic multivariate regression analyses, factors associated with intentional non-adherence were identified.

RESULTS

Among 154 subjects, 51 showed intentional non-adherence. Intentional non-adherence was associated with the following three factors: (a) the patients' beliefs with respect to taking medicines without anxiety, especially putting no value on mutual reliance on the patient-doctor relationship (P < 0.001) and putting great value on knowing the drug's side-effects (P < 0.001), (b) poor comprehension of general aspects of medication (P for trend < 0.001), and (c) being in the prime of life (40-59 years) (P = 0.011). Comprehension of the function of each medicine, experience of side-effects, anxiety about taking medicines, and the number of types of medicines taken, were not associated with non-adherence.

CONCLUSIONS

Beliefs on which individual Japanese patients with chronic diseases attach value in order to take medicines without anxiety were potential factors for intentional non-adherence. This emphasizes the necessity of a patient-oriented approach to take account of patients' personal beliefs about medicines to increase adherence rate in Japan.

[Analysis of factors influencing the self-regulation of medication and construction of an educational program for patients with chronic hepatic diseases]

The purpose of this study is to construct an educational program for patients with chronic hepatic diseases to avoid self-regulation of medication. We have statistically analyzed the influencing factors of self-regulation from the following 3 viewpoints. First, in the investigation of the number of and the kind of prescribed medicines, it was found that the number of prescribed medicines increased sharply at the stage of Liver Cirrhosis b. Secondly, in the survey of patients' awareness of medication, it was found that self-regulation was influenced by lack of understanding the effects of medicines and the necessity of medication, and by lack of understanding the clinical conditions. Especially, at the stage of Liver Cirrhosis b, self-regulation was strongly influenced by lack of understanding the clinical conditions. Lastly, in the evaluation of patients' characteristics by pharmacists, self-regulation was also strongly influenced by the level of understanding the necessity of medication, understanding the clinical conditions, a patient-doctor relationship, and anxiety about side-effects of medicines. Therefore we have constructed an educational program for patients from the viewpoint of medication. The information consists of two articles; one is the action mechanism of the medicine connected with the clinical conditions to help the patients understand the necessity of medication; the other is how to check the effect and adverse reaction of the medication by themselves to decrease the anxiety about side-effects. Consequently, the medication management and the consultation for inpatients with chronic hepatic diseases were standardized by incorporating the education with the information described above.

Administration of thymocytes derived from non-pregnant mice induces an endometrial receptive stage and leukaemia inhibitory factor expression in the uterus

We have previously reported that intravenous administration of splenocytes prepared from mice in the early stages of pregnancy promoted embryo implantation in pseudopregnant mice. Since a T-lymphocyte-rich, but not a monocyte-rich preparation from splenocytes enhanced embryo implantation, similar effects of thymocytes from non-pregnant mice on implantation were examined in this study. Thymocytes were prepared from immature 21 day old ICR female mice and the supernatant of a thymocyte suspension (Th-sup) was used as the control. Thymocytes or Th-sup were injected into the caudal vein of recipient mice on pseudopregnancy day 2, and blastocysts were transferred into the endometrial lumen. The implantation rates per recipient were significantly higher in the thymocyte-treated group. ICR mice were then oophorectomized on pseudopregnancy day 3. After 3-day progesterone supplementation, blastocysts were transferred with intravenous injection of thymocytes or Th-sup. Under progesterone supplementation, successful implantations were observed in the thymocyte-treated group, but not in the Th-sup-treated group. Reverse transcriptase-polymerase chain reaction analysis revealed that mRNA expression of leukaemia inhibitory factor in the uterus was induced by thymocyte administration, but not by Th-sup. Thymocytes were divided into two populations, CD4(+/-)CD8(-) group and CD4(-)CD8(+/-) group, by separation columns. On pseudopregnancy day 2, the separated thymocytes in each group or their supernatant were injected into the endometrial stroma of the recipient mice, and blastocysts were transferred into the endometrial lumen. The administration of CD4(+/-) CD8(-) lymphocytes significantly promoted implantation rates, but no effect was observed in the CD4(-) CD8(+/-) group. These findings showed that thymocytes, especially CD4-positive lymphocytes, facilitate embryo implantation, probably by regulating endometrial differentiation.

Splenocytes in early pregnancy promote embryo implantation by regulating endometrial differentiation in mice

We have reported that i.v. administration of splenocytes prepared from early pregnant mice promoted embryo implantation in pseudopregnant CD-1 (ICR) (closed colony) mice. In this study, the similar effects of splenocytes were confirmed using an inbred strain, BALB/c mice, and the mechanism was further investigated. Splenocytes were prepared from pregnancy day 4 (P4-spl) and dioestrus mice (Di-spl), and supernatant of P4-spl suspension (P4-sup) was used as controls. On pseudopregnancy day 2, splenocytes or supernatant were injected into caudal vein or endometrial stroma of the recipient mice, and blastocysts were transferred into the endometrial lumen. In both BALB/c and ICR strains, the implantation rates per recipient with i.v. and intraendometrial injection were significantly higher in P4-spl groups. Then, ICR mice were oophorectomized on pseudopregnancy day 3. After 3 day progesterone supplementation, blastocysts were transferred with i.v. injection of P4-spl and P4-sup, or s.c. oestradiol injection. Under progesterone supplementation, successful implantations were observed in the P4-spl- and oestradiol-treated groups, but not in P4-sup-treated group. Reverse transcriptase-polymerase chain reaction analysis revealed that messenger RNA expression of leukaemia inhibitory factor in the uterus was induced by P4-spl and oestradiol, but not by P4-sup. These findings showed that splenocytes of early pregnant mice promote embryo implantation by regulating endometrial differentiation.

Intravenous administration of splenocytes in early pregnancy changes the implantation window in mice

To clarify the role of immune cells in the reproductive phenomenon during early pregnancy, we investigated the effect of splenocytes obtained from mice in early pregnancy on embryo implantation. We prepared splenocytes from 5 week old pregnant ICR mice on day 4 (pregnancy day 4 splenocytes; P4-spl) and day 8 (pregnancy day 8 splenocytes; P8-spl), from 5 week old pseudopregnant ICR mice on day 4 (pseudopregnancy day 4 splenocytes; PP4-spl) and from 5 week old di-oestrous virgin mice (di-oestrous splenocytes; Di-spl). The supernatants (P4-sup, P8-sup, PP4-sup and Di-sup) derived from the suspensions of P4-spl, P8-spl, PP4-spl and Di-spl respectively, were used in the control groups. The recipient pseudopregnant mice (6 weeks of age) were injected i.v. with splenocytes (2 x 10(7) cells) or supernatants as controls, and embryo transfer was performed on day 2. Embryo implantation was evaluated 7 days later under laparotomy. The successful implantation rate per embryo was markedly higher compared with the control groups in the P4-spl (30.5 +/- 8.55 versus 1.0 +/- 1.37%, n = 200, P < 0.01) and P8-spl (20.1 +/- 10.3 versus 1.17 +/- 1.62%, n = 200, P < 0.05) groups. On the other hand, a slight but not significant increase was observed in the PP4-spl (8.33 +/- 8.80% versus 1.5 +/- 1.37%, n = 200) and Di-spl (9.0 +/- 5.76% versus 2.3 +/- 2.28%, n = 200) groups. Among the splenocyte administration groups, the implantation rate in the P4-spl group was significantly higher than in the PP4-spl and Di-spl groups (P < 0.01). These findings indicate that i.v. administration of splenocytes can change the murine implantation window. Since the splenocytes during early pregnancy are most effective on embryo implantation, peripheral immune cells in early pregnancy may be involved in embryo implantation.

The use of intra-endometrial embryo transfer for increasing the pregnancy rate

It has been demonstrated previously that pregnancy can be achieved by the direct insertion of embryos into the endometrial stroma (intra-endometrial embryo transfer) of mice. In this study we evaluated whether intra-endometrial transfer resulted in a higher pregnancy rate than conventional embryo transfer. Mouse blastocysts (ICR strain), recovered on day 4 of pregnancy, were transferred into pseudopregnant day 2, day 3 and day 4 mice of the same strain; 1-, 2- and 8-cell embryos were also transferred into pseudopregnant day 4 mice. In intra-endometrial embryo transfer, a 27 gauge injection needle was inserted near the utero-tubal junction into the endometrial stroma and then removed; one blastocyst was transferred into each uterine horn with a glass micropipette. Conventional transfers were performed simultaneously as controls. The pregnancy rates and embryonic viability rates were evaluated 9 days after embryo transfer. Furthermore, the rates of live birth for intra-endometrial and conventional embryo transfers were compared when blastocysts were transferred into pseudopregnant day 4 uteri by both methods. In the transfer to pseudopregnant day 2 recipients, the pregnancy and embryonic viability rates were significantly higher (P < 0.01) in intra-endometrial [23.4 (11/47) versus 15.9% (15/94)] than in conventional embryo transfer [4.3 (2/46) versus 2.2% (2/92)]. In the transfer to pseudopregnant day 3 recipients, both rates were also higher (P < 0.01) in intra-endometrial [90.9 (40/44) versus 87.5% (77/88)] than in conventional transfer [67.4 (31/46) versus 64.1% (59/92)].(ABSTRACT TRUNCATED AT 250 WORDS)

Developmental potential of frozen-thawed human blastocysts

PURPOSE

To examine the possibility of freezing human embryos at late cleaved stages (morula or blastocyst stage), we cryopreserved human embryos 5 days (day 5) or 6 days (day 6) after insemination and investigated their developmental potential after thawing.

MATERIALS AND METHODS

One hundred nineteen morphologically good-quality human embryos from 43 women undergoing in vitro fertilization treatment between 1991 and 1992 were frozen using dimethylsulfoxide as a cryoprotectant. The embryos were cryopreserved for 5 to 30 months. After thawing they were then cultured in vitro for 24 hr to investigate their developmental potential. Survival rates and developmental rates were morphologically assessed after 24 hr of in vitro culture.

RESULTS

Developmental rates were significantly (P < 0.01 or P < 0.05) lower than survival rates at every developmental stage. There was no difference in total survival rates between embryos frozen 5 days after insemination (78.2%; 54/69) and embryos frozen 6 days after insemination (70.0%; 35/54). However, the developmental rates after 24 hr of culture was significantly (P < 0.05) lower for embryos frozen 6 days after insemination (6.0%; 3/50) than for embryos frozen 5 days after insemination (18.8%; 13/69). Only two embryos developed into fetuses after transfer into the uterus (1.7%; 2/119).

CONCLUSIONS

From the results, the developmental potential of frozen-thawed human blastocysts was found to be significantly reduced, even though the blastocysts were of morphologically good quality. Longer in vitro exposure of embryos appears to reduce their developmental potential.

Relationship between the day of embryo transfer and the outcome in human in vitro fertilization and embryo transfer

PURPOSE

To clarify the optimal date of embryo transfer (ET), we retrospectively analyzed the relationship between the day of ET and the outcome in human in vitro fertilization and embryo transfer (IVF-ET).

METHOD

Of a total of 307 human IVF-ET cycles performed at Kyoto University Hospital between January 1990 and March 1994, we focused on 207 cases of IVF-ET cycles in which two or three good-quality embryos were transferred. These 207 IVF-ET cycles consisted of 54 Day 2 ET cycles, 79 Day 3 ET cycles, 46 Day 4 ET cycles, and 28 Day 5 ET cycles. We compared the pregnancy and live-birth (plus ongoing pregnancy) rates among these four ET groups.

RESULTS

The pregnancy rates of ET on Days 2 to 4 were not significantly different, whereas Day 5 ET produced a significantly lower pregnancy rate (Day 2, 29.6%; Day 3, 32.9%; Day 4, 30.4%; Day 5, 10.7%). Similar results were obtained for the live-birth (plus ongoing pregnancy) rates (Day 2, 20.3%; Day 3, 18.9%; Day 4, 17.9%; Day 5, 7.1%).

CONCLUSIONS

These results suggest that the day of ET does not fundamentally affect the pregnancy rate in human IVF-ET provided that transfer is made before Day 5.

Morphology of the synovium during its differentiation and development in the mouse knee joint. A histochemical, SEM and TEM study

The prenatal and postnatal development of the mouse knee joint was investigated by transmission and scanning electron microscopy. In the prenatal stage, following the appearance of a narrow intercellular cleft between two skeletal elements on the 16th fetal day, clefting extended into the lateral synovial mesenchyme. In some regions, the extension of the cleft was very rapid, but in a certain region (future fat pad region), it was somewhat slower. Macrophage-like cells appeared in the synovial mesenchyme on the 16th fetal day, and then increased in number, and were distributed as if they were clustering around the presumptive clefting zone in the future fat pad region on the 17th-18th fetal day. This suggests that macrophage-like cells may participate in joint development, as they phagocytize and remove some kinds of solid extracellular matrix, and facilitate the cleft extension. In the early postnatal stage, scanning electron microscopic observations showed that there were two different types of cell in the synovial lining. One of them exhibited a surface morphology corresponding to that of macrophages: a spherical cell body and numerous pseudopodia. The other type of cell exhibited various cell shapes with many cytoplasmic processes extending along the synovial surface.