[Establishment and validation of nomogram prediction model for complicated acute appendicitis]

Objective: To establish and internally validate a nomogram model for predicting complicated acute appendicitis (CA). Methods: The clinical data from 663 acute appendicitis patients from the First Affiliated Hospital of Anhui University of Traditional Chinese Medicine from October 2015 to October 2022 were retrospectively analyzed. There were 411 males and 252 females, aged (M (IQR)) 41 (22) years (range: 18 to 84 years). There were 516 cases of CA and 147 cases of uncomplicated acute appendicitis. The minimum absolute contraction and selection operator regression model was used to screen the potential relative factors of CA, and the screened factors were included in the Logistic regression model for multivariate analysis. Software R was used to establish a preoperative CA nomogram prediction model, the receiver operating characteristic curve of the model was drawn, and the value of area under the curve (AUC) was compared to evaluate its identification ability, and the Bootstrap method was used for internal verification. Results: The elderly (age≥60 years) (OR=2.428, 95%CI: 1.295 to 4.549), abdominal pain time (every rise of 1 hour) (OR=1.089, 95%CI: 1.072 to 1.107), high fever (body temperature≥39 ℃) (OR=1.122, 95%CI: 1.078 to 1.168), total bilirubin (every rise of 1 μmol/L) (OR=2.629, 95%CI: 1.227 to 5.635) were independent relative factors of CA (all P<0.05). The AUC of this model was 0.935 (95%CI: 0.915 to 0.956). After internal verification using the Bootstrap method, the model still had a high discrimination ability (AUC=0.933), and the predicted CA curve was still in good agreement with the actual clinical CA curve. Conclusion: The clinical prediction model based on the elderly (age≥60 years), prolonged abdominal pain time, high fever (body temperature≥39 ℃), and increased total bilirubin can help clinicians effectively identify CA.

[Phenotype-genotype analysis of the autosomal recessive hereditary hearing loss caused by OTOA variations]

Objective: To analyze the phenotypic-genotypic characteristics of hereditary deafness caused by OTOA gene variations. Methods: Family histories, clinical phenotypes and gene variations of six pedigrees were analyzed, which were diagnosed with hearing loss caused by OTOA gene variations at the PLA General Hospital from September 2015 to January 2022. The sequence variations were verified by Sanger sequencing and the copy number variations were validated by multiplex ligation-dependent probe amplification (MLPA) in the family members. Results: The hearing loss phenotype caused by OTOA variations ranged from mild to moderate in the low frequencies, and from moderate to severe in the high frequencies in the probands, which came from six sporadic pedigrees, among which a proband was diagnosed as congenital deafness and five were diagnosed as postlingual deafness. One proband carried homozygous variations and five probands carried compound heterozygous variations in OTOA gene. Nine pathogenic variations (six copy number variations, two deletion variations and one missense variation) and two variations with uncertain significance in OTOA were identified in total, including six copy number variations and five single nucleotide variants, and three of the five single nucleotide variants were firstly reported [c.1265G>T(p.Gly422Val),c.1534delG(p.Ala513Leufs*11) and c.3292C>T(p.Gln1098fs*)]. Conclusions: OTOA gene variations can lead to autosomal recessive nonsyndromic hearing loss. In this study, the hearing loss caused by OTOA defects mostly presents as bilateral, symmetrical, and postlingual, and that of a few presents as congenital. The pathogenic variations of OTOA gene are mainly copy number variations followed by deletion variations and missense variations.

[Analysis of COL1A1 gene variation and clinical prevention and treatment in patients with Van der Hoeve syndrome]

Objective: To investigate the clinical phenotype, treatment and prevention of Van der Hoeve syndrome, and analyze the variation characteristics of its related gene COL1A1. Methods: Hearing and sequencing data of syndromic deafness patients who had undergone genetic testing for deafness at the Chinese People's Liberation Army General Hospital since January 2008 to October 2020 were retrospectively reviewed. The variation of the COL1A1 gene and return visits to traceable patients and families were summarized, the disease progress and clinical treatment effects were analyzed, and the prevention strategies were discussed. Results: A total of 7 patients with COL1A1 gene mutation underwent clinical intervention. The mutation sites were c.1342A>T (p.Lys448*), c.124C>T (p.Gln42*), c.249insG(p.Ala84*), c.668insC(p.Gly224*), c.2829+1G>C, c.1081C>T (p.Arg361*), c.1792C>T (p.Arg598*), of which c.1081C>T and c.1792C>T had been previously reported, and the remaining 5 were novo mutations that have not been reported. All the 7 probands underwent stapes implantation and received genetic counseling and prevention guidance. Conclusions: Van der Hoeve syndrome belongs to osteogenesis imperfecta type Ⅰ. The disease has high penetrance. Timely surgical intervention for hearing loss can improve the life quality in patients. Accurate genetic counseling and preimplantation genetic diagnosis can achieve the primary prevention for the disease.

[Phenotype and genotype analysis of recessive hereditary moderate sensorineural hearing loss caused by new mutations in OTOGL gene]

Objective: To perform the phenotype and genetic analysis on two families with moderate sensorineural hearing impairment and determine the cause of deafness. Methods: The phenotype and genetic analysis was performed on the two hearing impairment pedigrees coming to Chinese PLA General Hospital from January 2014 to August 2020. DNA samples of the proband from family 1 and the parents from family 2 were collected and tested through next generation sequencing on all deafness genes, and Sanger sequencing was performed to verify the mutation sites. The reported pathogenic variants of the otogelin-like (OTOGL) gene, the autosomal recessive inherited deafness genes that cause moderate sensorineural hearing loss and the clinical manifestations of the deafness genes that have the similar expression location as the OTOGL gene were summarized and analyzed. Results: The pathogenic variants in the families were compound heterozygous variants in the OTOGL gene c.2773C>T/c.2826C>G (p.Arg925*/p.Tyr942*) and c.4455G>A/c.875C>G (Trp1485*/p.Ser292*), respectively. c.2773C>T was an already reported pathogenic variant causing hearing impairment in the literature, while c.2826C>G, c.4455G>A and c.875C>G were novel reported variant sites. The above four variants were classified as pathogenic variants according to the variant interpretation standards and guideline of the Amercian College of Medical Genetics and Genomics. Conclusions: Pathogenic variants in OTOGL gene is an important genetic factor leading to moderate sensorineural hearing loss. The newly discovered variant sites c.2826C>G, c.4455G>A and c.875C>G enrich the variant spectrum of OTOGL gene. The results of the current study provide a basis for genetic counseling of the related families and a new target for the treatment of hereditary hearing loss in the future.

[Surgical strategy of minimally invasive cochlear implantation]

Cochlear implantation is currently the most effective treatment for patients with severe-to-profound sensorineural hearing loss. How to achieve minimally invasive treatment, preserve the residual hearing, and further improve curative effect and reduce surgical complications is the goal of cochlear implantation practice. This article introduces the minimally invasive cochlear implantation technique in terms of the idea of minimally invasive operation, the advantages of electric acoustic stimulation, the key points of electrode implantation technique, the design of surgical incision, and the precise processing of perioperative period. This technique not only has the merits of less operative damage and better hearing and speech rehabilitation after surgery, but also reserves favorable structures and function for the future application of gene therapy and hair cell regeneration technique. Therefore, it is strongly recommended for further promotion in clinical practice.

[PTPN11 and the deafness]

Summary PTPN11 gene encodes tyrosine phosphatase SHP-2 which locates on chromosome 12（12q24.1）, expresses in most embryonic and adult tissues, and plays pivotal roles in cell proliferation, differentiation, survival and cell death. SHP-2 apparently participates in signaling events downstream of RAS-MAPK and JAK/STAT. Diseases related to PTPN11 gene mutations include the Noonan syndrome（NS） and the NS with Multiple Lentigines（NSML）. Both NS and NSML contain the phenotypes of deafness, craniofacial anomalies, short stature, congenital heart defects, skin disorders, ophthalmologic abnormalities and cancer predisposition.

[Case report and diagnosis of Noonan syndrome with multiple lentigines with deafness as its main clinical feature]

Summary Noonan syndrome with multiple lentigines（NSML） is a disorder with syndromic hearing loss. Abnormalities of other systems in NSML have received increasing attention, but hearing loss is rarely concerned. And due to the incomplete phenotype, some patients with NSML maybe missed or maybe confused with other syndromic deafness such as Waardenburg syndrome. Our study will familiarize more otolaryngologists with Leopard syndrome. A 5-year-old boy with bilateral sensorineural hearing loss and numerous symmetrically distributed dark brown macules that had good effect of cochlear implantation was collected in this study. And his father had bilateral sensorineural hearing loss and numerous symmetrically distributed dark brown macules. Waardenburg syndrome was initially diagnosed by clinical phenotype and its molecular etiology was confirmed by gene diagnosis. Waardenburg syndrome-related deafness genes and 131 known deafness genes were not identified by second-generation sequencing. Whole-exon sequencing was performed for 4 individuals in the family and the results were confirmed by Sanger sequencing. This study confirmed the diagnosis by identifying a disease-causing mutation in the PTPN11 gene, which was a heterozygous missense mutation at p. Tyr279Cys（c. 836A>G）. The mutation co-segregated with hearing loss in the family. Our results demonstrated that hearing loss in this family was caused by heterozygous mutations in PTPN11. These cases will familiarize more otolaryngologists with NSML, and they emphasize the importance of considering NSML as a possible cause of hearing problems.

[One novel pathologic variation in KMT2D cause Kabuki syndrome with hearing loss as the main phenotype and related research on types of deafness]

Objective:To make the molecular diagnosis of a patient complaining hearing loss and with specific facial features, developmental delay, vertebral dysplasia, hypotonia and other suspected phenotypes of Kabuki make-up syndrome（KS）; to investigate the characteristics and main phenotypes of KS. Method:①Whole-exome sequencing and bioinformatics analysis were performed for proband and her parents. ②Literatures describing the clinical features of KS patients with clear molecular diagnosis from the period of Aug 2010 to Mar 2019 were collected from databases of PubMed and CNKI. Result:①The proband carries the c. 15777insT variant（p. Pro5260fs*10） in KMT2D gene. The variant causes the termination codon to appear prematurely. KMT2D c. 15777insT was classified as PVS1+PS1+PM2 according to the ACMG variation interpretation standard, which is a disease-causing mutation. The c. 15777insT was first reported as a pathogenic mutation of KS. ②77 peer-reviewed publications on KS were analysed including 462 patients with KS. The main findings were intellectual disability（305 cases）, congenital heart defects（227 cases）, hypotonia（184 cases）, short fingers（147 cases）, short stature（144 cases）, cleft palate（139 cases）, hearing loss（101 cases） and developmental delay（99 cases）. Of the 101 patients with hearing loss, 11 were confirmed to have conductive hearing loss（1 with recurrent otitis media）, 3 with mixed hearing loss, 12 with sensorineural deafness（1 with recurrence otitis media） and 75 patients with unidentified types of deafness（28 with recurrent otitis media）. Conclusion:KS involves defects of a wide range of organs, with each organ showing different severity of symptoms, which is easily misdiagnosed from the phenotypes. We suggest the diagnosis on hearing loss in KS patients should be strengthened. KMT2D and KDM6A are two pathogenic genes that have been identified for KS. With the increase of age, its typical clinical phenotypes become more and more obvious. When there is only atypical suspected KS symptoms in the early neonatal period, relevant genetic test should be performed as soon as possible to achieve early diagnosis and intervention.

[Histocompatibility of an original Chinese-made mid-urethral sling in a rabbit model]

Objective: To evaluate the histocompatibility of an original Chinese-made mid-urethral sling (Repelvica mid-urethral sling). Methods: In total 10 female New Zealand white rabbits were implanted with Repelvica mid-urethral sling or tension-free vaginal tape-obturator tape (TVT-O; Gynecare). Both brands of sling were implanted under deep fascia of the abdominal wall and in the space between vagina and bladder. All animal groups were sacrificed at set time intervals (4 weeks and 12 weeks), and the abdominal and vaginal slings were harvested for histological evaluation. Results: All slings appeared to be well incorporated into the abdominal wall and anterior vaginal wall. All specimens showed a thin, loose, fibrous interface between the synthetic graft and abdominal wall or vaginal wall, along with mild inflammatory reaction from 4 weeks to 12 weeks. Abdominal grafts of Repelvica mid-urethral sling and TVT-O induced comparable tissue reaction (histological score 10.5 versus 10.5 at 4 weeks, 10.0 versus 9.5 at 12 weeks; both P>0.05). Vaginal grafts of Repelvica mid-urethral sling had lower histological score than TVT-O (histological score 6.0 versus 12.0 at 4 weeks, 8.5 versus 12.5 at 12 weeks), however the differences were not statistically significant (both P>0.05). Conclusions: Chinese-made Repelvica mid-urethral sling exhibits good histocompatibility. Vaginal graft of Repelvica mid-urethral sling evoks minor tissue reaction, which could be attributed to its lightweighted property and favored its clinical application.

Sequence characterization, polymorphism, and tissue expression profile of an effector immediate-early gene: activity-regulated cytoskeletal associated protein gene (Arc/Arg3.1) in swamp and river buffalo

The activity-regulated cytoskeletal associated protein (Arc/Arg3.1) has been implicated in experience-dependent synaptic plasticity and memory formation. However, information regarding its coding gene in buffalo remains scarce. In this study, the full-length of Arc/Arg3.1 was isolated and characterized (accession No. JX491649) and genetic variations of six river buffalo and eight swamp buffalo were investigated. A tissue expression profile was obtained using semi-quantitative reverse transcription-polymerase chain reaction. The coding region sequence of Arc/Arg3.1 contained 1191 nucleotides encoding a putative protein of 396 amino acids with a theoretical isoelectric point (pI) and molecular weight (Mw) of 5.4 and 45.2 kDa, respectively. Four polymorphisms (c.63T>C, c.228T>C, c.558G>A, and c.625G>C) were found in buffalo; however, only substitution c.625G>C was non-synonymous, leading to an amino acid change from Val to Leu at the 209th position of the Arc/Arg3.1 protein sequence. Bioinformatics analysis revealed that this substitution had no significant effect on Arc/Arg3.1 function (subPSEC = -1.4039, Pdeleterious = 0.1685), which indicated that Arc/Arg3.1 was highly conserved and functionally important in buffalo. Phylogenetic analysis revealed that the gene is closely related to that of Bos taurus and Bos grunniens. The gene was moderately expressed in the hypophysis and the placenta; it was weakly expressed in the kidney, milk, mammary gland, cerebrum, lung, heart, rumen, fat, and uterus; and it was almost silent in the muscle, liver, and skin. These findings will provide further insights into the structure and function of the immediate-early gene in buffalo.

Skeletal deterioration induced by RANKL infusion: a model for high-turnover bone disease

RANKL was administered continuously to rats for 28 days to investigate its potential as a disease model for the skeletal system. Bone turnover rates, bone material, structural and mechanical properties were evaluated. RANKL infusion caused overall skeletal complications comparable to those in high bone-turnover conditions, such as postmenopausal osteoporosis.

INTRODUCTION

RANKL is an essential mediator for osteoclast development. No study has examined in detail the direct skeletal consequences of excess RANKL on bone turnover, mineralization, architecture, and vascular calcification. We, therefore, administrated soluble RANKL continuously into mature rats and created a bone-loss model.

METHODS

Six-month-old Sprague-Dawley (SD) rats were assigned to three groups (n = 12) receiving continuous administration of saline (VEH) or human RANKL (35 microg/kg/day, LOW or 175 microg/kg/day, HI) for 28 days. Blood was collected routinely during the study. At sacrifice, hind limbs and aorta were removed and samples were analyzed.

RESULTS

High dose RANKL markedly stimulated serum osteocalcin and TRAP-5b levels and reduced femur cortical bone volume (-7.6%) and trabecular volume fraction (BV/TV) at the proximal tibia (-64% vs. VEH). Bone quality was significantly degraded in HI, as evidenced by decreased femoral percent mineralization, trabecular connectivity, and increased endocortical bone resorption perimeters. Both cortical and trabecular bone mechanical properties were reduced by high dose RANKL. No differences were observed in the mineral content of the abdominal aorta.

CONCLUSIONS

Continuous RANKL infusion caused general detrimental effects on rat skeleton. These changes are comparable to those commonly observed in high-turnover bone diseases such as postmenopausal osteoporosis.

Soluble RANKL induces high bone turnover and decreases bone volume, density, and strength in mice

Receptor activator for nuclear factor-kappa B ligand (RANKL) is an essential mediator of osteoclastogenesis. We hypothesized that administration of soluble RANKL to mice would result in high turnover and deleterious effects on both cortical and trabecular bone. For 10 days, 10-week-old C57BL/6J female mice (n = 12/group) were given twice-daily subcutaneous injections of human recombinant RANKL (0.4 or 2 mg/kg/day) or inert vehicle (VEH). Bone turnover was greatly accelerated by RANKL, as evidenced by the 49-84% greater levels of serum TRAP-5b (bone resorption marker) and 300-400% greater levels of serum alkaline phosphatase (bone formation marker). RANKL resulted in significantly greater endocortical bone erosion surface (79-83%) and periosteal bone formation rate (64-87%) vs. VEH. Microcomputed tomographic (microCT) analysis of the proximal tibia indicated a reduction in trabecular volume fraction (-84%) for both doses of RANKL. Cortical bone geometry and strength were also negatively influenced by RANKL. MicroCT analysis of the femoral diaphysis indicated significantly lower cortical bone volume (-10% to -13%) and greater cortical porosity (8-9%) relative to VEH. Biomechanical testing of the femur diaphysis revealed significantly lower maximum bending load (-19% to -25%) vs. VEH. Bone strength remained correlated with bone mass, independent of RANKL stimulation of bone turnover. These findings are consistent with the hypothesis that soluble RANKL could be an important etiologic factor in pathologic bone loss. RANKL also has potential utility as a model for studying the consequences of high bone turnover on bone quality and strength in animals.

Progesterone primes zona pellucida-induced activation of phospholipase A2 during acrosomal exocytosis in guinea pig spermatozoa

We investigated, using guinea-pig spermatozoa as a model, whether phospholipase A2 (PLA2) is involved in progesterone or zona pellucida (ZP)-stimulated acrosomal exocytosis, if progesterone enhances ZP-induced activation of PLA2, and mechanisms underlying PLA2 regulation. Spermatozoa were capacitated and labeled in low Ca2+ medium with [14C]choline chloride or [14C]arachidonic acid, washed, and then exposed to millimolar Ca2+ and progesterone and/or ZP. Each agonist stimulated decrease of phosphatidylcholine (PC) and release of arachidonic acid and lysoPC, indicative of PLA2 activation. Aristolochic acid (a PLA2 inhibitor) abrogated lipid changes and exocytosis, indicating that these lipid changes are essential for exocytosis. Exposure of spermatozoa to submaximal concentrations of both progesterone and ZP resulted in a synergistic increase of arachidonic acid and lysoPC releases, and exocytosis, suggesting that, under natural conditions, both agonists interact to bring about acrosomal exocytosis. Progesterone-induced PLA2 activation appears to be mediated by a GABA(A)-like receptor, because bicuculline (a GABA(A) receptor antagonist) blocked arachidonic acid release and exocytosis. In agreement with this, GABA mimicked progesterone actions. ZP-induced activation of PLA2 seemed to be transduced via G(i) proteins because pertussis toxin blocked arachidonic acid release and acrosomal exocytosis. PLA2 may be regulated by PKC because progesterone- or ZP-induced release of arachidonic acid was blocked by the PKC inhibitors staurosporine or chelerythrine chloride. PLA2 could also be regulated by the cAMP-PKA pathway; inclusion of the PKA inhibitor 14-22 amide or H-89 led to a reduction in arachidonic acid release or exocytosis after progesterone or ZP. Taken together, these results suggest that PLA2 plays an essential role in progesterone or ZP-stimulated exocytosis with progesterone priming ZP action.

Zona pellucida induces activation of phospholipase A2 during acrosomal exocytosis in guinea pig spermatozoa

Phospholipase A(2) (PLA(2)) is activated in spermatozoa in response to progesterone and Ca(2+) ionophores, but to our knowledge, no study has yet reported zona pellucida (ZP)-induced activation of PLA(2). We investigated whether PLA(2) is involved in ZP-stimulated acrosomal exocytosis, if Ca(2+) is required for activation of PLA(2), and signal transduction pathways modulating PLA(2) using guinea pig sperm as a model. Spermatozoa were capacitated and labeled in low-Ca(2+) medium with [(14)C]choline chloride or [(14)C]arachidonic acid and were then exposed to millimolar Ca(2+) and various reagents and stimulated with ZP. Precapacitated spermatozoa exposed to millimolar Ca(2+) and stimulated with ZP experienced increases in arachidonic acid (AA) and lysophosphatidylcholine (lysoPC) levels and a parallel decrease in phosphatidylcholine level; these changes are indicative of PLA(2) activation. Simulation with ZP also led to acrosomal exocytosis in a high proportion of spermatozoa. Lipid changes and exocytosis were prevented if spermatozoa were exposed to aristolochic acid, a PLA(2) inhibitor, before treatment with ZP. Stimulation with ZP in medium without added Ca(2+) or in medium with millimolar Ca(2+) and EGTA or La(3+) resulted in no lipid changes or exocytosis. Pretreatment with pertussis toxin, a G(i) protein inhibitor, before stimulation with ZP blocked the release of AA and lysoPC as well as acrosomal exocytosis. Exposure of spermatozoa to the diacylglycerol (DAG) kinase inhibitor R59022 before ZP stimulation led to a significant increase in generation of lysoPC and exocytosis. Taken together, these results indicate very strongly that PLA(2) plays an essential role in ZP-induced exocytosis in spermatozoa, that PLA(2) activation requires Ca(2+) internalization, and that PLA(2) activation is regulated by signal transduction pathways involving G proteins and DAG.

Inhibition of hamster sperm acrosomal enzyme by gossypol is closely associated with the decrease in fertilization capacity

To elucidate the mechanism of sterility induced by gossypol, we studied the relationship between the activities of acrosomal enzymes and their fertilizing capacity in the hamster. The results showed that the ability of spermatozoa to penetrate into bovine cervical mucus, hyperactivated motility (HAM) and fertility in vivo were significantly inhibited when spermatozoa were exposed to gossypol (2.5 microg - 60 microg/mL) for 15 min in vitro. Also, following administration of gossypol (12.5 mg/kg/day) for 6 weeks, sperm motility, HAM and rate of fertilization in vitro by the hamster cauda epididymal spermatozoa were significantly decreased and the extracts of testis delayed dispersion of the cumulus oophorus cells, suggesting that hyaluronidase and other acrosomal enzymes might be inhibited by gossypol. In addition, acrosin and arylsulfatase activities were also markedly inhibited. These data show that the inhibition of acrosin and arylsulfatase activities is the main cause of gossypol-induced infertility. The inhibition was dependent upon gossypol dose and the duration of administration. Thus, the assay of acrosin and arylsulfatase activities may provide a useful tool for monitoring sterility induced by gossypol.

Effect of protein kinase C on guinea pig sperm acrosome reaction induced by progesterone

AIM

To investigate the effect of protein kinase C (PKC) on the guinea pig sperm acrosome reaction (AR) induced by progesterone (P4).

METHODS

Guinea pig spermatozoa were preincubated in MCM-Ca2+ DF medium at 38.5 degrees C under 5% CO2/air for 6-6.5 h for capacitation, and were then washed through a three-step gradient Percoll, resuspended in MCM-Ca2+ DF and adjusted to 5 x 10(9) cells/L. The AR was assessed by means of phase-contrast microscopy (expressed as percent of AR) 15 min after different reagents were added.

RESULTS

In the presence of Ca2+ 2 mmol/L, phorbol 12,13-dibutyrate (PDB) or the permanent synthetic diacylglycerol, 1-oleoyl-2-acetyl-sn-glycerol (OAG) initiated the AR of spermatozoa in a concentration-related manner, whereas staurosporine (STA) exhibited an inhibition of the AR. PDB and OAG significantly enhanced P4-induced AR that was greater than that treated with either agonist separately. STA markedly inhibited the P4-induced AR. The AR induced by PDB was completely antagonized by inclusion of egtazic acid. Also, both egtazic acid and nifedipine antagonized the AR induced by P4 and PDB + P4. In addition, neomycin also prevented the P4-induced AR. This effect could be partly reversed by PDB.

CONCLUSION

Activation or inhibition of PKC significantly plays an important role in the signal transduction pathway for the physiological AR.

[Capacitating action of GABA and progesterone in spermatozoa of human and guinea pig in vitro]

This study was designed to investigate whether GABA is involved in the capacitation effect and hyperactivated motility (HAM). Spematozoa from fertile men and retired guinea pigs were washed in modified BWW of 45% 90% Percoll gradient with 26 mg BSA/ml and in low Ca(2+)-MCM of 30%-55%-85% Percoll gradient (approximately 23 micromol/L Ca(2+)) respectively. The samples were preincubated for 2 h under 5% CO2 in air at 38.5 with or without GABA, progesterone (P(4)), GABA(A) receptor agonists or antagonists, and then exposed to 1 micromol/L (for human) or 5 micromol/L (for guinea pigs) calcium ionophore A 23187 for 15 min. The capacitation effect and HAM were assessed by using the chlortetracycline (CTC) staining method and phase-contrast microscopy. Motility was 80% 85% after all additions. The results showed that addition of GABA or P(4) at 5 micromol/L to the incubation medium resulted in a significant increase in the sum of B (characteristic of capacitated cell) and AR (acrosome recation) pattern (65.9% and 61.7% respectively), corresponding to capacitated spermatozoa in human, as compared to the control (37.3%). Likewise, the capacitating effect of GABA on spermatozoa in guinea pigs showed a concentration-dependent increase from 1 to 10 micromol/L(AR: 27.0 +/- 1.9% to 51.6 +/-2.8%). In addition, P(4) potentiated the capacitating effect of GABA when combined with GABA in the capacitation stage. The capacitating effect of GABA was mimicked by a GABAA receptor agonist muscimol. However, this effect was completely blocked by a GABA(A) receptor antagonist (-)-bicuculline and a GABA(A)/Cl(-) receptor antagonist picrotoxin. Furthermore, GABA markedly increased the HAM of P(4) on guinea pig spermatozoa, which was mediated obviously by the influx of extracellular Ca(2+) because the GABA-induced AR could be prevented by EGTA. These results indicate that GABA and P(4) are involved in the capacitation of spermatozoa in both human and guinea pigs through a GABA(A) receptor-mediated mechanism.

Recurrence of maltreatment: an application of the National Child Abuse and Neglect Data System (NCANDS)

OBJECTIVE

The research describes and compares patterns of maltreatment recurrence across multiple states using large samples, confirms the patterns of recurrence found in the literature, and explores unreported patterns of recurrence.

METHOD

A recurrence data set for calendar years 1994 and 1995 was constructed from the multi-state case level data from the National Child Abuse and Neglect Data System. These data were available for 10 states and included a range from 2,419 to 99,288 substantiated or indicated report-child pairs per state. A common set of data constructs lent consistency to data construction and analysis, while preserving differences in policy. Event History Analysis (survival) techniques were used.

RESULTS

Single site studies were confirmed across the 10 states. These include the pattern where neglect is most likely to recur, followed by physical abuse and then sexual abuse. Similarly, younger children are more likely to recur. A finding of the analysis is that the likelihood of recurrence increases in a systematic and consistent fashion based upon the sequential ordering of recurrent maltreatment events. Also, the likelihood of recurrence is associated with the provision of postinvestigative services.

CONCLUSION

Highly consistent patterns of recurrence were observed across states. Children experiencing multiple recurrences compared to no recurrence or one recurrence may represent a special at risk population requiring additional research. Adequate baselines and an understanding of recurrence is needed when considering recurrence as an outcome indicator or in developing risk assessment tools. Important recurrence patterns may be difficult to detect reliably with relatively small samples.

[GABA initiates the acrosome reaction and fertilizing ability in human sperm]

The present study was undertaken to investigate whether GABA induced the acrosome reaction (AR) and fertilizing ability, as well as its possible mode of action in human spermatozoa. Spermatozoa from fifteen health fertile men isolated by the swim-up technique were preincubated in a modified BWW with 0.35% BSA for 1-11 h under 5% CO2 in 95% air at 37 degrees C. Aliquots of spermatozoa were collected at 0, 1, 3, 5, 7, 9 and 11 h of incubation for evaluation of the AR by chlortetracycline (CTC) staining. The sperm penetration assay (SPA) was carried out by using the zona-free hamster oocyte test. Intracellular calcium ([Ca2+]i) concentrations were determined by means of fluorescent probe Frua-2/AM. GABA at 1.25 mumol/L significantly induced the AR in human spermatozoa preincubated for 3 h, with a maximal response in preincubated for 9 h, and the effect changed in a concentration-dependent manner. The maximal stimulatory effect was observed with 1.25 mumol/L GABA, and the AR then decreased markedly with further increase of GABA concentration to 10 mumol/L. Exposure of preincubated spermatozoa to GABA in combination with progesterone resulted in a higher proportion of the AR as compared with that obtained with each agonist applied alone. In addition, GABA prompted a rapid increase in interacellular [Ca2+]i. Furthermore, the AR induced by GABA was prevented by inclusion of 1 mmol/L EGTA or 100 mumol/L La3+. Also, GABA enhanced significantly the ability of spermatozoa penetrating zona-free hamster oocytes and the index of fertilization. These results indicate that GABA may be involved in the modulation of the AR and the fertilization process in capacitated human spermatozoa through a calcium mediated mechanism, thus opening up possibilities for studies of signal transductions through activation of the GABAA receptor present on the sperm surface.

gamma-Aminobutyric acid (GABA) induces the acrosome reaction in human spermatozoa

The sperm acrosome reaction takes place in response to progesterone and zona pellucida. Progesterone may act on more than one type of surface receptor, of which one is a gamma-aminobutyric acid (GABA) type A-like receptor. Although there is direct evidence of GABA initiation of mouse sperm acrosome reaction, there are conflicting results regarding GABA-induced exocytosis in human spermatozoa. We have examined whether GABA would initiate exocytosis in human spermatozoa using the chlortetracycline assay and a zona-free hamster oocyte test. Human spermatozoa preincubated for > or = 3 h in Biggers-Whitten-Whittingham medium with 0.35% bovine serum albumin underwent acrosome reactions in response to GABA, with maximal responses in spermatozoa preincubated for 9 h. The effect was concentration-dependent. Preincubated spermatozoa treated with GABA were able to fertilize a higher proportion of zona-free oocytes, with a higher number of spermatozoa penetrating each oocyte. Exposure of preincubated spermatozoa to GABA and progesterone together resulted in a higher proportion of acrosome reactions than when each agonist was used alone. The effect of GABA was mediated by the influx of extracellular Ca2+ because inclusion of EGTA or the Ca2+ channel antagonist La3+ prevented GABA-induced acrosome reactions. These results indicate that GABA can initiate exocytosis in capacitated human spermatozoa and open up possibilities for studies of signalling mechanisms activated upon occupancy of the GABAA receptor present on the sperm surface.

[The transducing pathway of Ca2+ influx during progesterone-initiated acrosome reaction of guinea pig sperm]

Progesterone and gamma-aminobutyric acid (GABA) could initiate the acrosome reaction (AR) in guinea pig spermatozoa, which was independent of extracellular Cl- in vitro, and a potentiation effect between progesterone and GABA was demonstrated. Antagonists of GABAA receptor/Cl- channel, picrotoxin and bicuculline, have no effect on the progesterone-induced AR, but they can significantly inhibit the GABA-induced AR in (Cl-)-containing medium. While in (Cl-)-deficient medium, picrotoxin has significant inhibitory effect on both progesterone- and GABA-induced AR, both progesterone- and GABA-induced AR are inhibited by the Ca2+ channel blocker, nifedipine. These results suggest that a GABAA/Cl- receptor complex and a Ca2+ channel might be involved in the influx of extracellular Ca2+ during the progesterone-induced AR.

Inhibition of rabbit sperm acrosomal enzymes by gossypol

The effect of gossypol on the activities of 10 acrosomal enzymes of the rabbit sperm was evaluated. Acrosin, Azocoll proteinase, neuraminidase, and arylsulfatase were significantly inhibited or completely inactivated by 12-76 microM gossypol. Hyaluronidase, beta-glucuronidase, and acid phosphatase were inhibited only at a higher concentration of gossypol (380 microM). Phospholipase C, alkaline phosphatase, and beta-N-Acetyl glucosaminidase were not inhibited even at 380 microM gossypol. Gossypol was found to be a noncompetitive inhibitor of arylsulfatase with a Ki of 120 microM. The inhibition was reversible and dose-dependent. As the acrosomal enzymes were more sensitive to the inhibition by gossypol compared to sperm enzymes involved in glycolysis or energy production, these assays may serve as a more reliable indicator for monitoring the occurrence of gossypol-induced sterility.

Effect of spermine on sperm capacitation of guinea pig in vitro

Spermine (Sp) 10(-5) mM had vigorous activity of guinea pig spermatozoa, while it completely abolished sperm forward motility (SFM) at a concentration of 10(-3) mM. There appeared to be a dose relationship to inhibition to motility. 2-Difluoromethylornithine 10 mM antagonized the Sp-induced inhibition of SFM after 3 h of incubation. Capacitation of a guinea pig sperm was inhibited by Sp in a concentration-dependent manner. The majority of acrosome-reacted sperm did not display hyperactivated motility. Precapacitated sperm were able to undergo the acrosome reaction (AR) in the presence of Sp. Moreover, Sp-mediated inhibition of capacitation was a reversible process. Once sperm capacitation was completed, Sp no longer inhibited AR. Before capacitation, the content of Sp in spermatozoa was 4.5 +/- 0.5 micrograms/5 x 10(7) cells, whereas in case of capacitated spermatozoa it was significantly decreased (2.1 +/- 0.4 micrograms/5 x 10(7) cells). The penetration of spermatozoa into the zona-free hamster eggs in the presence of Sp was markedly decreased, but it did not affect the fertilizability of ova as compared to the control. These results suggest that Sp may be an inhibitory agent of sperm capacitation in guinea pig in vitro, and it may also be involved in the modulation of capacitation.

[Spermine inhibition of in vitro fertilizing ability of human spermatozoa and its possible mode of action]

The direct effect of spermine at various concentrations (0.25-8.0 mmol/L) on in vitro fertilizing ability of human spermatozoa was evaluated by the penetration test of zona-free hamster egg. To study the effect of spermine on capacitation, as judged by the rate of penetration, spermatozoa were incubated in BWW with various concentrations of spermine for 6 h at 37 degrees C. The hyperactivated motility of spermatozoa was markedly inhibited by spermine at a concentration of 4.0 mmol/L. The penetration rate was decreased proportionally to the dose of spermine used. Spermatozoa were incubated in BWW with 0.5 mmol/L spermine for 6 h and another 4 h after spermine was washed off with spermine-free BWW. The percentage of penetration was comparable to that of the control. Therefore, spermine-mediated inhibition of capacitation was reversible. Moreover, exogenous dbcAMP (0.5-1.0 mmol/L) or caffeine (10 mmol/L) could antagonize significantly the spermine-induced inhibition of capacitation with a correlation coefficient of 0.990. The content of spermine in fertile men spermatozoa was assayed by HPLC. Before capacitation spermine in spermatozoa was 7.05 micrograms/10(7) cells, whereas after capacitation it was no longer detectable, indicating that spermine may be an inhibitor of in vitro capacitation in human sperm. To study the effect of spermine on capacitated sperm, spermine was added to the BWW medium after sperm had been preincubated in spermine-free BWW. The persistent presence of spermine could interfere with spermatozoa attachment to, binding to and penetration into zona-free hamster eggs, which was related to the concentration (r = 0.820) used.(ABSTRACT TRUNCATED AT 250 WORDS)