In Situ Photo-Crosslinkable Protein Bioadhesive for Bone Graft Fixation

Bone grafting is a fundamental dental surgery procedure widely used for implant placement and periodontal disease management treatments. Despite its broad applications, vertical bone augmentation presents unique challenges, including the risk of graft displacement due to gravitational and masticatory forces. Traditional physical stabilization methods introduce additional complexities and risks, underscoring the need for innovative fixation technologies. This study aimed to develop an in situ photo-crosslinkable bioadhesive hydrogel (iPBAH) as a multifunctional bone graft binder to enhance the process of bone reconstruction. The bioadhesive is composed of mussel-derived adhesive protein (MAP) fused with the cell-adhesive peptide RGD. The numerous tyrosine residues in MAP facilitate rapid photo-crosslinking, enabling efficient hydrogel formation using visible blue light. Subsequently, iPBAH underwent comprehensive characterization to evaluate its suitability as a multifunctional bone graft binder. iPBAH efficiently underwent in situ crosslinking through harmless exposure to visible light within minutes and displayed several exceptional properties, including a microporous structure, underwater adhesion, extended durability, high compressive strength, and biocompatibility. In vivo assessments, using male Sprague-Dawley rats, demonstrated that iPBAH binder significantly enhanced bone regeneration in a rat calvarial bone defect model. The in situ crosslinking of the iPBAH binder during bone graft transplantation can effectively fill irregular and complex defect shapes while simultaneously preventing graft material leakage. The improved physical attributes of the bound graft material can enhance its resistance to external forces, thereby ensuring sustained retention over time. Moreover, the interaction between iPBAH and surrounding tissues promotes adhesion and integration of the graft material with host tissues in the defect area. In addition, the included RGD peptide in iPBAH can augment inherent cell recruitment, adhesion, and growth, consequently expediting osteogenesis.

Predicting pregnancy in women undergoing in-vitro fertilization with basal serum follicle stimulating hormone levels between 10.0 and 11.9 IU/L

OBJECTIVE

To evaluate the results of the in vitro fertilization (IVF) cycle outcomes in women whose borderline basal follicle stimulating hormone (FSH) levels were between 10.0 and 11.9 IU/L and to analyze the predictors of pregnancy in this population.

MATERIAL AND METHODS

A prospective cohort study was performed at an academic teaching hospital; participants were infertile couples in which the women were undergoing IVF treatment and had borderline basal highest FSH levels between 10.0 and 11.9 IU/L. Statistical modeling was performed to determine risk factors for pregnancy and clinical pregnancy.

RESULTS

A clinical pregnancy rate of 26.5% per cycle and 35% per patient was found in the study population. Among all subjects and non-intracytoplasmic sperm injection (ICSI) subjects, younger age, higher gravidity, higher number of mature follicles on day of Human Chorionic gonadotrophin (hCG) triggering, higher number of oocytes retrieved, and number of embryos produced were significant discriminators between individuals who conceived and those who did not. However, only the number of embryos predicted those who had a clinical pregnancy when compared with those who did not. Higher gravidity, and basal estradiol (E2) levels, and lower maximum basal FSH levels predicted clinical pregnancy in non-ICSI patients. Among ICSI patients, the only predictor of pregnancy was a thicker endometrium. A trend towards higher pregnancy rates was noted in ICSI patients.

CONCLUSION

We showed that pregnancy rates per cycle and per patient in this population were not significantly different than those in patients with a basal FSH level below 10.0 IU/L. Preliminary evidence suggests that ICSI is the fertilization method of choice in these patients.

Natural orifice specimen extraction versus conventional laparoscopically assisted right hemicolectomy

BACKGROUND

This case-control study compared the clinical outcomes of totally laparoscopic hemicolectomy with natural orifice specimen extraction (NOSE) and the conventional laparoscopically assisted approach for right-sided colonic cancer.

METHODS

Consecutive patients who underwent totally laparoscopic mobilization of the right colon with transvaginal resection, anastomosis and specimen extraction between April 2007 and December 2009 were matched by various clinicopathological characteristics with patients who had conventional laparoscopically assisted procedures.

RESULTS

Thirty-four patients in each group were studied. The number of lymph nodes harvested and the resection margin status were similar in the two groups. After NOSE, patients experienced less pain (mean(s.e.m.) pain score on day 1: 4·2(0·3) versus 5·7(0·3), P = 0·001; on day 3: 2·6(0·2) versus 3·5(0·2), P = 0·010) and had a shorter hospital stay (mean(s.d.) 7·9(0·8) versus 8·8(1·5) days; P = 0·003). The NOSE group had less surgical morbidity than the laparoscopically assisted group, but the difference was not significant (4 of 34 versus 9 of 34; P = 0·119). After a median follow-up of 23 (range 5-40) months, there was no transvaginal access-site recurrence or posterior colpotomy-related complications. NOSE was associated with significantly better cosmetic results (mean(s.d.) score 7·5(1·7) versus 6·6(1·8); P = 0·037).

CONCLUSION

The NOSE approach is feasible with favourable short-term surgical outcomes.

Ectopic pregnancy rates with frozen compared with fresh blastocyst transfer

OBJECTIVE

To compare the rate of ectopic pregnancy (EP) with fresh versus frozen blastocyst transfer in our program during the same time period.

DESIGN

Retrospective analysis.

SETTING

University IVF program.

PATIENT(S)

Women who achieved a clinical pregnancy after IVF between 1998 and 2005.

INTERVENTION(S)

In our program, cryopreservation is performed at the blastocyst stage. Embryo transfer was performed 1 to 1.5 cm short of the fundus by abdominal ultrasound guidance.

MAIN OUTCOME MEASURE(S)

The incidence of EP was examined in relation to fresh versus frozen blastocyst transfer.

RESULT(S)

In the frozen blastocyst group, there were 5 EPs out of 180 clinical pregnancies (2.8%), and there were 10 EPs out of 564 clinical pregnancies (1.8%) in the fresh blastocyst group.

CONCLUSION(S)

The rate of EP is not significantly increased after the transfer of frozen thawed blastocysts compared with fresh blastocyst transfer.

Benefit of intracytoplasmic sperm injection in patients with a high incidence of triploidy in a prior in vitro fertilization cycle

OBJECTIVE

To test the hypothesis that intracytoplasmic sperm injection (ICSI) overcomes a high incidence of tripronucleate zygotes resulting from standard insemination in a previous cycle.

DESIGN

A retrospective analysis of matched-pair cycles.

SETTING

Assisted reproductive technologies (ART) program of Brigham and Women's Hospital.

PATIENT(S)

Ninety-five patients with a > or = 20% incidence of tripronucleate zygotes in an IVF cycle with use of ICSI in a subsequent attempt.

INTERVENTION(S)

Cycles with either standard insemination or ICSI.

MAIN OUTCOME MEASURE(S)

Incidence of diploid (2pn) and triploid (3pn) zygotes and number and quality of embryos obtained.

RESULT(S)

Patient age, ampules of gonadotropin used, peak E2, number of follicles at hCG trigger, and total number of oocytes were all significantly higher in the ICSI cycles, but the number of mature oocytes did not differ. After ICSI, the percentage of 2pn was higher (65.0% vs. 34.1%) and the percentage of 3pn was lower (5.0% vs. 33.9%) than after IVF, and more diploid embryos were obtained with ICSI (5.5 +/- 3.7 vs. 3.4 +/- 2.2 [mean +/- SD]). There was no difference in embryo quality between the two groups.

CONCLUSION(S)

ICSI appears beneficial in women with a high 3pn occurrence from IVF because it increases the number of diploid zygotes without affecting embryo quality.

Is there a role for preparatory cycle in ovum donation recipients?

PURPOSE OF REVIEW

In ovum donation cycles, the role of preparatory cycles to ensure proper endometrial development in the recipient remains controversial. As evidenced in the literature, endometrial receptivity is critical in conception. Therefore, endometrial preparation with exogenous hormones in addition to synchronization of the recipient and donor are essential in achieving a successful outcome.

RECENT FINDINGS

There are very limited data specifically examining the benefit of recipients undergoing preparatory cycles prior to their actual egg donation cycle. One study concluded that trial hormone replacement treatment cycles with endometrial biopsies may be useful in older reproductive-age women but not in younger women. Another study showed no difference in pregnancy rates between those who did and did not undergo preparatory cycles.

SUMMARY

Since one of the integral elements of preparatory cycles is determining endometrial dating, with relatively conflicting data, these mock cycles may not be as beneficial as expected. Therefore, for those who routinely use preparatory cycles, the potential risks, benefits, and costs of these cycles, increased hormonal exposure, the relatively invasive nature of the procedure, and time prior to performing them must be considered.

The role of preparatory cycles in ovum donation recipients: a retrospective study

PURPOSE

To determine whether preparatory cycles affect in vitro fertilization (IVF) outcome in ovum donation.

METHODS

Medical records of 98 ovum donation recipients undergoing their first egg donation cycle were analyzed retrospectively. Preparatory cycles were performed in 50 patients with leuprolide acetate, estrogen, and progesterone. An endometrial biopsy was performed on day 10-12 of progesterone supplementation, to determine adequacy of the preparatory cycle.

RESULTS

Pregnancy rates in women with and without preparatory cycles were 42.0% and 43.8%, respectively. Among ovum donation recipients who underwent preparatory cycles, the percentages of adequate endometrial biopsies in pregnant versus nonpregnant groups were 76.2% and 84.3%, respectively. No results showed statistical significance.

CONCLUSIONS

Preparatory cycles do not increase pregnancy rates in ovum donation recipients. In addition, no correlation was noted between adequate endometrial biopsies and higher pregnancy rates.

Assisted hatching is associated with a higher ectopic pregnancy rate

In a retrospective analysis of 623 clinical pregnancies conceived after IVF, a 5.4% ectopic pregnancy rate (14/258 clinical pregnancies) was found in cases where assisted hatching (AH) was performed compared to 2.2% (8/365) in the group without assisted hatching. In view of the widespread use of AH, it may be relevant to assess the effect of AH on the incidence of ectopic pregnancy in a large multicenter effort.

Ectopic pregnancy rates with day 3 versus day 5 embryo transfer: a retrospective analysis

Background

Blastocyst transfer may theoretically decrease the incidence of ectopic pregnancy following IVF-ET in view of the decreased uterine contractility reported on day 5. The purpose of our study is to specifically compare the tubal pregnancy rates between day 3 and day 5 transfers.

Methods

A retrospective analysis of all clinical pregnancies conceived in our IVF program since 1998 was performed. The ectopic pregnancy rates were compared for day 3 and day 5 transfers.

Results

There were 623 clinical pregnancies resulting from day 3 transfers of which 22 were ectopic (3.5%). In day 5 transfers, there were 13 ectopic pregnancies out of 333 clinical pregnancies (3.9%). The difference between these rates is not statistically significant (P = 0.8).

Conclusions

Our data suggests that the ectopic pregnancy rate is not reduced following blastocyst transfer compared to day 3 transfer. While there may be several benefits to extended culture in IVF, the decision to offer blastocyst transfer should be made independently from the issue of ectopic pregnancy risk.

Comparison of the sex ratio with blastocyst transfer and cleavage stage transfer

PURPOSE

To evaluate the sex ratio in births conceived with blastocyst transfer compared to day 3-ET.

METHODS

A retrospective analysis of IVF patients who became pregnant after blastocyst or cleavage stage transfer at Stanford University Hospital and a literature review were performed.

RESULT(S)

In the day 3-ET group, the male-to-female (M/F) ratio was 157/139 (53%/47%) compared to 97/66 (59.5%/40.5%) in the blastocyst group (P = 0.18). Similar trends have been found in individual studies in the literature but reached statistical significance in only one out of six reports reviewed. The combined data from our study and the literature show a male-to-female ratio of 797/594 (57.3%/42.7%) in blastocyst transfer compared to 977/932 (51.2%/48.8%) in day 3-ET (P = 0.001).

CONCLUSION(S)

Although individual studies may lack power to show an altered sex ratio with blastocyst transfer, the combined data presented in this report do suggest that the M/F ratio is higher with blastocyst transfer compared to cleavage stage transfer.

Incidence of monozygotic twinning with blastocyst transfer compared to cleavage-stage transfer

OBJECTIVE

To evaluate the incidence of monozygotic twinning (MZT) in pregnancies conceived after blastocyst transfer compared to cleavage-stage transfer.

DESIGN

Retrospective study.

SETTING

University IVF program.

PATIENT(S)

All IVF patients with viable pregnancies conceived during a 4-year period.

INTERVENTION(S)

Blastocyst transfer or day 3 ET.

MAIN OUTCOME MEASURE(S)

Incidence of MZT assessed by transvaginal ultrasound.

RESULT(S)

There were 11 incidences of MZT in 197 viable pregnancies (5.6%) with blastocyst transfer compared to 7 of 357 viable pregnancies (2%) with day 3 ET. In 10 of 18 pregnancies, MZT was observed in the setting of a higher order multiple gestation (6 of 11 for blastocyst transfer and 4 of 7 for day 3 ET). In the day 3 ET group, assisted hatching or intracytoplasmic sperm injection (ICSI) did not increase MZT (4 of 213, 1.9%) compared to cycles without zona breaching (3 of 144, 2.1%). Similarly, in the blastocyst-transfer group, ICSI did not increase the incidence of MZT (4 of 74, 5.5% for ICSI and 7 of 123, 5.7% for non-ICSI IVF).

CONCLUSION(S)

Compared to day 3 ET, blastocyst transfer appears to significantly increase the incidence of gestations with MZT. This information should be taken into account when counseling patients about the pros and cons of extended culture.

Uterine leiomyomas and their effect on in vitro fertilization outcome: a retrospective study

PURPOSE

The effect of uterine leiomyomas on the outcome of in vitro fertilization (IVF) treatment has been controversial. This study was undertaken to clarify influence of fibroids on IVF success, in a large population with age and other potential confounding variables controlled for in the analysis.

METHODS

A population of 141 patients with and 406 without leiomyomata undergoing their first IVF cycle was studied.

RESULTS

The association between uterine leiomyomas and assisted reproduction treatment outcome was not statistically significant (OR = 0.73, 95% CI: 0.49-1.19, p = 0.21) after controlling for age and other risk factors. Also, fibroids neither affected the risk of spontaneous abortion (OR = 1.06, 95% CI: 0.44-2.60) nor the risk of ectopic pregnancy (OR = 0.78, 95% CI: 0.08-8.02). Location of fibroids (intramural vs. submucosal/subserosal) and their size had no significant effect on pregnancy outcome.

CONCLUSIONS

Results from our analyses indicated that in vitro fertilization outcome was not affected by the presence of uterine leiomyomas. Therefore, in patients with normal uterine cavities and fibroids less than a certain size (i.e., < 7 cm), undergoing myomectomies as a prerequisite for assisted reproduction treatment is seriously questionable.

Microsatellite alteration in histologically normal lung tissue of patients with non-small cell lung cancer

Microsatellite alteration (MSA) has been observed in a fraction of non-small cell lung cancer (NSCLC). Most prior studies regarding MSA in lung cancer have usually used adjacent non-malignant lung tissues as a source of constitutional DNA. However, these normal tissues might have genetic alterations because the entire field of bronchial tree is exposed to the same carcinogenic insult. The aim of this study was to search if MSA is present in the histologically normal lung tissue of patients with NSCLC. Tumor and corresponding normal lung tissue specimens were obtained from 20 patients with NSCLC. Normal lung tissue specimens were obtained from either the opposite end of resected surgical samples or as distant from the tumor as possible. They were examined histopathologically and confirmed as normal by H-E stain. Patients' peripheral lymphocytes were used as the source for the normal DNA. Sixteen markers on 3p and 9p (nine and seven markers, respectively) were used. MSA was detected in seven of 20 (35%) histologically normal lung tissue specimens at a frequency similar to that observed in tumor tissue (eight of 20, 40%). Five cases showed MSA in both normal lung tissue and the corresponding tumor. In these five cases, MSA in normal lung tissue was detected at the same microsatellite markers which MSA was detected in the corresponding tumor. The number and size of novel bands in normal lung tissue was identical to that in tumor tissue except in one case. In which case, the same pattern of MSA was found in both normal lung tissue and corresponding tumor tissue at two markers. However, at one marker, while one identical novel band was detected in normal lung tissue and corresponding tumor tissue, another novel band was found only in tumor tissue. In two of 12 patients whose tumor was negative for the presence of MSA, MSA was detected in normal lung tissue. These results indicate that genetic alterations are widely distributed in the lung tissue of patients with lung cancer and provide considerable support for the field cancerization theory. Screening for MSA in resected normal lung tissue might be a new method to identify patients at high risk for developing second primary lung cancers.

Tissue-preferential expression of a rice alpha-tubulin gene, OsTubA1, mediated by the first intron

The genomic clone encoding an alpha-tubulin, OsTubA1, has been isolated from rice (Oryza sativa L.). The gene consists of four exons and three introns. RNA-blot analysis showed that the gene is strongly expressed in actively dividing tissues, including root tips, young leaves, and young flowers. Analysis of chimeric fusions between OsTubA1 and beta-glucuronidase (GUS) revealed that the intron 1 was required for high-level GUS expression in actively dividing tissues, corresponding with normal expression pattern of OsTubA1. Fusion constructs lacking the intron 1 showed more GUS staining in mature tissues rather than young tissues. When the intron 1 was placed at the distal region from 5'-upstream region or at the 3'-untranslated region, no enhancement of GUS expression was observed. Sequential deletions of the OsTubA1 intron 1 brought about a gradual reduction of GUS activity in calli. These results suggest that tissue-preferential expression of the OsTubA1 gene is mediated by the intron 1 and that it may be involved in a mechanism for an efficient RNA splicing that is position dependent.

T-DNA insertional mutagenesis for functional genomics in rice

We have produced 22 090 primary transgenic rice plants that carry a T-DNA insertion, which has resulted in 18 358 fertile lines. Genomic DNA gel-blot and PCR analyses have shown that approximately 65% of the population contains more than one copy of the inserted T-DNA. Hygromycin resistance tests revealed that transgenic plants contain an average of 1.4 loci of T-DNA inserts. Therefore, it can be estimated that approximately 25 700 taggings have been generated. The binary vector used in the insertion contained the promoterless beta-glucuronidase (GUS) reporter gene with an intron and multiple splicing donors and acceptors immediately next to the right border. Therefore, this gene trap vector is able to detect a gene fusion between GUS and an endogenous gene, which is tagged by T-DNA. Histochemical GUS assays were carried out in the leaves and roots from 5353 lines, mature flowers from 7026 lines, and developing seeds from 1948 lines. The data revealed that 1.6-2.1% of tested organs were GUS-positive in the tested organs, and that their GUS expression patterns were organ- or tissue-specific or ubiquitous in all parts of the plant. The large population of T-DNA-tagged lines will be useful for identifying insertional mutants in various genes and for discovering new genes in rice.

Analysis of p73 in human borderline and invasive ovarian tumor

p73 is a novel gene that has high sequence homology and similar gene structure to the tumor suppressor gene p53. We analysed p73 in seven ovarian carcinoma cell lines and a total of 63 human borderline and invasive ovarian tumor samples. Loss of heterozygosity at this locus was observed in 50% of invasive tumors but in none of the borderline tumors. Biallelic expression of the gene was observed in the heterozygous tumor tissues. Direct sequencing and single-strand conformation polymorphism analyses of the p73 cDNA sequence homologous to the highly mutatable region of p53 did not reveal any mutations. When compared to the primary cultures of normal human ovarian surface epithelial cells and immortalized cell lines, four of the seven ovarian carcinoma cell lines, 71% of the invasive tumors, and 92% of the borderline tumor tissues express elevated levels of p73 transcript. Except for the OVCA3 cell line, Western blot analysis of the nuclear extracts prepared from the cell lines showed concordant levels of p73 protein. Our analysis also demonstrated the expression of a spliced variant of p73 transcript with the omission of exon 2 solely in the cancer cell lines and invasive tumor tissues. This exon 2-spliced transcript would give rise to a truncated p73 protein without the N-terminal transactivation domain. In reminiscence of the dominant negative phenotype of the N-terminal truncated variants of another p53-related gene, p63, the expression of the truncated p73 variant form in ovarian tumors may play an important role in the pathogenesis of ovarian cancer.

A TGF-beta-inducible cell adhesion molecule, betaig-h3, is downregulated in melorheostosis and involved in osteogenesis

Melorheostosis is a rare bone disease characterized by linear hyperostosis and associated soft tissue abnormalities. The skin overlying the involved bone lesion is often tense, shiny, erythematous, and scleodermatous. In order to look for genes differentially expressed between the normal and involved skin, we cultured skin fibroblasts from the skin lesions of several afflicted patients, and identified differentially expressed genes by reverse dot-blot hybridization. We found that the genes human TGF-beta-induced gene product (betaig-h3), osteoblast-specific factor 2, osteonectin, fibronectin, and type I collagen were all downregulated in the affected skin fibroblasts, with betaig-h3 the most significantly affected. The expression of betaig-h3 was induced by TGF-beta in both affected and normal fibroblasts. In an effort to determine the mechanism of bone and skin abnormalities in melorheostosis, we made recombinant betaig-h3. Both immobilized and soluble recombinant betaig-h3 proteins with or without an RGD motif inhibited bone nodule formation of osteoblasts in vitro. Taken together, our results suggest that altered expression of several adhesion proteins may contribute to the development of hyperostosis and concomitant soft tissue abnormalities of melorheostosis, with betaig-h3 in particular playing an important role in osteogenesis.

Clinical characteristics of Peutz-Jeghers syndrome in Korean polyposis patients

Peutz-Jeghers syndrome is an autosomal dominant inherited disorder characterized by hamartomatous polyps in the small bowel and mucocutaneous pigmentation. Patients with Peutz-Jeghers syndrome often present as surgical emergencies with complications of the polyps, such as intussusception, bowel obstruction, and bleeding. Recently an increased risk of malignancies has also been reported. This study was initiated to determine the clinical features of Peutz-Jeghers syndrome in Korean patients, with special attention to the development of malignancies. Thirty patients with Peutz-Jeghers syndrome were investigated; their median age was 23.5 years, and symptoms appeared at a median age of 12.5 years. Family history was positive in one-half of cases, and mucocutaneous pigmentation was observed in almost all patients (93%). The jejunoileum was the most frequent site of the polyps, and there were generally 10-100 polyps. Multiple laparotomies were performed in a substantial portion of the patients, due mainly to polyp-induced bowel obstruction, and the surgical interventions were begun at a relatively young age (average 21.4 years). Four cases of small-bowel cancer and one case of breast cancer were detected in probands, at a relatively young age (mean 36 years). Cancers of the small bowel, stomach, colon, breast and cervix were diagnosed in the first relatives of the probands. Close follow-up from an early age should thus be performed in patients with Peutz-Jeghers syndrome as they are at high risk of surgical emergency and development of malignancy.

Cloning and molecular analyses of a gibberellin 20-oxidase gene expressed specifically in developing seeds of watermelon

To understand the biosynthesis and functional role of gibberellins (GAs) in developing seeds, we isolated Cv20ox, a cDNA clone from watermelon (Citrullus lanatus) that shows significant amino acid homology with GA 20-oxidases. The complementary DNA clone was expressed in Escherichia coli as a fusion protein, which oxidized GA(12) at C-20 to the C(19) compound GA(9), a precursor of bioactive GAs. RNA-blot analysis showed that the Cv20ox gene was expressed specifically in developing seeds. The gene was strongly expressed in the integument tissues, and it was also expressed weakly in inner seed tissues. In parthenocarpic fruits induced by 1-(2-chloro-4-pyridyl)-3-phenylurea treatment, the expression pattern of Cv20ox did not change, indicating that the GA 20-oxidase gene is expressed primarily in the maternal cells of developing seeds. The promoter of Cv20ox was isolated and fused to the beta-glucuronidase (GUS) gene. In a transient expression system, beta-glucuronidase staining was detectable only in the integument tissues of developing watermelon seeds.

Fertilization and in vitro development of porcine oocytes following intracytoplasmic injection of round spermatid or round spermatid nuclei

The objective of this study was to determine fertilization rates and developmental ability of porcine oocytes following injection of round spermatid and round spermatid nucleus with artificial activation either 2 h before or immediately after injection. Electrical stimulation at 2 h before spermatid injection significantly increased the incidence of normal fertilization compared with that following injection without stimulation or with stimulation immediately after injection. Incidences of formation of 2 pronuclei and of apposition were not different in oocytes following intracytoplasmic spermatid and spermatid nucleus injection. Chromosome analysis revealed that most oocytes were diploid either following round spermatid or round spermatid nucleus injection. There was no diploid set of chromatin in oocytes at 20 h following sham injection. At 6 d following injection blastocoele formation was seen in the oocytes following round spermatid (25%) and round spermatid nucleus injection (27%). However, none of the oocytes developed to the blastocyst stage 6 d following sham injection. The average cell numbers of blastocysts 8 d after injection of spermatid and spermatid nucleus were 99 and 87, respectively. These results suggest that electrical stimulation before injection enhances the incidence of fertilization following round spermatid injection in the pig. Our study also indicates that either the round spermatid or it's nucleus can be used to produce viable embryos by injection into unfertilized porcine oocytes.

Intracytoplasmic injection of porcine, bovine, mouse, or human spermatozoon into porcine oocytes

We determined the incidence of activation, male pronuclear formation, and apposition of pronuclei in porcine oocytes following intracytoplasmic injection of various porcine sperm components and foreign species spermatozoa, such as that of cattle, mouse or human. The porcine oocytes were activated by injection of a spermatozoon or an isolated sperm head. In contrast, injection of either sperm tail or a trypsin- or NaOH-treated sperm head failed to induce oocyte activation. Because injection of mouse, bovine, or human spermatozoon activated porcine oocytes, the sperm-borne activation factor(s) is not strictly species-specific. Male pronuclear formation and pronuclear apposition were observed in porcine oocytes following injection of porcine, bovine, mouse or human spermatozoa. Electrical stimulation following sperm cell injection did not enhance the incidence of male pronuclear formation or pronuclear apposition compared with sperm cell injection alone (P > 0.1). Following porcine sperm injection, the microtubular aster was organized from the neck of the spermatozoon, and filled the whole cytoplasm. In contrast, following injection of bovine, mouse, or human spermatozoon, the maternal-derived microtubules were organized from the cortex to the center of the oocytes, which seems to move both pronuclei to the center of oocytes. Cleavage to the two-cell stage was observed at 19-21 hr after injection of porcine spermatozoon. However, none of the oocytes following injection of mouse, bovine, or human spermatozoa developed to the mitotic metaphase or the two-cell stage. These results suggested that the oocyte activating factor(s) is present in the perinuclear material and that it is not species-specific for the porcine oocyte. Self-organized microtubules seemed to move the pronuclei into center of oocytes when foreign species spermatozoa were injected into porcine oocytes.

Anocutaneous advancement flap closure of high anal fistulas

BACKGROUND

Fistula-in-ano may be treated by closing the internal fistulous opening. An anocutaneous flap was developed to facilitate this closure.

METHODS

From October 1995 to April 1997, 40 patients with high trans-sphincteric or suprasphincteric anal fistulas were treated. The important components of the procedure are excision of the internal opening, excision or curettage of the tract, closure of the internal opening by an anocutaneous flap, and external drainage.

RESULTS

In two patients (5 per cent) the flap separated and the sutured internal opening was exposed. One of the two was healed 4 weeks later. In the remaining 38 patients, complete healing occurred 2-3 weeks after operation. No patient was incontinent of gas or stool.

CONCLUSION

This procedure is technically simple, heals rapidly with minimal scarring, and cures anal fistulas while preserving the anal sphincter.

Fertilization of porcine oocytes following intracytoplasmic spermatozoon or isolated sperm head injection

We demonstrated normal fertilization processes (as determined by pronuclear formation, pronuclear apposition and syngamy) in porcine oocytes either following intracytoplasmic spermatozoon (ICSI) or isolated sperm head injection. Microtubule organization and chromatin configuration were investigated in these oocytes during the first cell cycle. Following ICSI, the microtubular aster was organized from the neck of the spermatozoon and filled the whole cytoplasm. These male-derived microtubules appear to move both pronuclei to the center of oocytes. These cytoskeletal changes are analogous to those seen following conventional fertilization. In contrast, following isolated sperm head injection, the sperm aster was not seen. Instead, the microtubule matrix was organized from the cortex and then filled the whole cytoplasm in all cases in normally fertilized oocytes following injection (n=35). This organization is similar to what has been shown in the parthenogenetically activated oocytes. Chromosome analysis revealed that the oocytes injected with isolated sperm heads were fertilized normally. At 7 days following injection, the incidence of blastocoele formation following ICSI (38%) and isolated sperm head injection (22%) was higher than that following sham injection (2%). These results suggested that successful fertilization and preimplantation development occurred in porcine oocytes following either ICSI or isolated sperm head injection. Our results also indicated that fertilization processes can occur by self-assembled microtubules within cytoplasm in the absence of a sperm centrosome.

Expression of 32/67-kDa laminin receptor in laminin adhesion-selected human colon cancer cell lines

Laminin promotes the malignant phenotype, and the expression of certain laminin receptors is increased in malignancy. Previously, we demonstrated that a laminin-adhesive subclone of a human colon cancer cell line showed increased tumorigenicity in nude mice and increased affinity of the beta1 integrin for laminin relative to the laminin-non-adhesive subclone. The total amount of either beta1 integrin protein or mRNA did not increase. As levels of the 32/67-kDa laminin receptor (67LR) correlate with malignancy, we examined 67LR expression in the laminin adhesion-selected human colon cancer cells. The laminin-adhesive subclone, which was more tumorigenic in both heterotopic and orthotopic locations than in a laminin-non-adhesive subclone, showed cell-surface membrane staining of 67LR, whereas the laminin-non-adhesive subclone showed cytoplasmic staining of 67LR. No difference in either the amount of 67LR mRNA or the amount of protein was observed in the parental cells than in the laminin-adhesive and non-adhesive subclones. When assayed on a laminin affinity column, more 67LR molecules bound to the column with cell extracts from the laminin-adhesive subclone than was observed with the non-adhesive subclone. These findings suggest that the increased tumorigenicity of laminin adhesion-selected tumour cells might be due to an alteration in the distribution and/or adhesiveness of multiple receptors including 67LR and beta1 integrin.

Effect of Matrigel and laminin peptide YIGSR on tumor growth and metastasis

Basement membrane has a variety of effects on tumor cells and promotes malignant behavior. Tumor cell growth is enhanced both in vitro and in vivo in mice in the presence of basement membrane. This has led to the ability to grow various tumors including human biopsy specimens in nude mice. Furthermore, low cell numbers can be used when coinjected with Matrigel, a basement membrane extract. The basement membrane glycoprotein laminin is important in promoting invasive behavior and the level of a 32/67 kDa laminin receptor has been shown to correlate with malignancy. A sequence of five amino acids, tyrosine-isoleucine-glycine-serine-arginine (YIGSR) has been shown to recognize this receptor and to reduce experimental metastases (tail vein injection resulting in colonization of the lung) and subcutaneous tumor growth. This peptide is active in both models either when coinjected or when daily intraperitoneal injections are given after tumor growth has initiated. YIGSR does not effect cell arrest but does inhibit angiogenesis which is necessary for tumor growth. YIGSR also appears to have an additional antitumor effect via its interaction with a specific receptor. YIGSR-adherent cells established after 30 successive selections on YIGSR-coated dishes in vitro formed more lung colonies after intravenous injection and larger tumors after subcutaneous injection than the parent B16F10 melanoma cells. The YIGSR-non-adherent cells formed fewer lung colonies and smaller subcutaneous tumors. These data demonstrate the importance of laminin-tumor cell interactions in malignancies and suggest that a short sequence from laminin has multiple effects in reducing tumor growth and spread.(ABSTRACT TRUNCATED AT 250 WORDS)