Occipital and parietal cortex participate in a cortical network for transsaccadic discrimination of object shape and orientation.

Saccades change eye position and interrupt vision several times per second, necessitating neural mechanisms for continuous perception of object identity, orientation, and location. Neuroimaging studies suggest that occipital and parietal cortex play complementary roles for transsaccadic perception of intrinsic versus extrinsic spatial properties, e.g., dorsomedial occipital cortex (cuneus) is sensitive to changes in spatial frequency, whereas the supramarginal gyrus (SMG) is modulated by changes in object orientation. Based on this, we hypothesized that both structures would be recruited to simultaneously monitor object identity and orientation across saccades. To test this, we merged two previous neuroimaging protocols: 21 participants viewed a 2D object and then, after sustained fixation or a saccade, judged whether the shape or orientation of the re-presented object changed. We, then, performed a bilateral region-of-interest analysis on identified cuneus and SMG sites. As hypothesized, cuneus showed both saccade and feature (i.e., object orientation vs. shape change) modulations, and right SMG showed saccade-feature interactions. Further, the cuneus activity time course correlated with several other cortical saccade/visual areas, suggesting a 'functional network' for feature discrimination. These results confirm the involvement of occipital/parietal cortex in transsaccadic vision and support complementary roles in spatial versus identity updating.

Damage to the human dentate gyrus impairs the perceptual discrimination of complex, novel objects.

The hippocampus (HPC), and the dentate gyrus (DG) subregion in particular, is purported to be a pattern separator, orthogonally representing similar information so that distinct memories may be formed. The HPC may also be involved in complex perceptual discrimination. It is unclear if this role is limited to spatial/scene stimuli or extends to the discrimination of objects. Also unclear is whether the DG itself contributes to pattern separation beyond memory. BL, an individual with bilateral DG lesions, was previously shown to have poor discrimination of similar, everyday objects in memory. Here, we demonstrate that BL's deficit extends to complex perceptual discrimination of novel objects. Specifically, BL was presented with closely matched possible and impossible objects, which give rise to fundamentally different 3D perceptual representations despite being visually similar. BL performed significantly worse than controls when asked to select an odd object (e.g., impossible) amongst three identical counterpart objects (e.g., possible) presented at different rotations. His deficit was also evident in an atypical eye fixation pattern during this task. In contrast, BL's performance was indistinguishable from that of controls on other tasks involving the same objects, indicating that he could visually differentiate the object pairs, that he perceived the objects holistically in 3D, and that he has only a mild weakness in categorizing object possibility. Furthermore, his performance on standardized neuropsychological measures indicated intact mental rotation, visual-spatial attention, and working memory (visual and auditory). Collectively, these results provide evidence that the DG is necessary for complex perceptual discrimination of novel objects, indicating that the DG might function as a generic pattern separator of a wide range of stimuli within high-level perception, and that its role is not limited to memory.

Tethered cord in children with anorectal malformations with emphasis on rectobladder neck fistula.

PURPOSE: To find the incidence of tethered cord (TC) in patients with anorectal malformations (ARM) and to determine the relationship between bowel/urinary control and TC in a subset of patients with rectobladder neck fistula (RBNF). METHODS: The database of a tertiary medical center was retrospectively collected for all patients treated for ARM from 1980 to 2012. All patients with TC and RBNF were identified. RESULTS: Among 790 patients, who underwent screening for TC, 285(36%) were diagnosed with TC. Eleven of 37 screened patients with RBNF were diagnosed with TC. The median follow-up period was 49 months (range 2-222 months). TC was diagnosed in 3/18(16.6%) patients with sacral ratio (SR) ≥ 0.7; 4/12(33.3%) with SR 0.41-0.69; and 4/7(57.1%) patients with SR 0-0.4. The association of TC in RBNF patients had a negative influence in the prognosis for bowel and urinary control. CONCLUSION: The incidence of TC among patients with ARM is 36%. Incidence of TC among patients with RBNF correlates with SR value and is higher with lower SR. Patients with RBNF and TC have dismal prognosis for bowel control, unrelated to their SR status. Many unresolved questions related to the management of ARM patients with asymptomatic TC still remain.

Optimizing the process of fertility preservation in pediatric female cancer patients - a multidisciplinary program.

BACKGROUND: Current evidence indicates sub-optimal incidence of fertility preservation (FP) in eligible patients. We present herein our designated multidisciplinary program for FP in pediatric and adolescent population and present our data on FP in female patients. METHODS: Pediatric patients (age 0-18) who were candidate for highly gonadotoxic treatments were referred to FP program for a multidisciplinary discussion and gonadal risk-assessment followed by either oocyte cryopreservation or ovarian cryopreservation (OCP) for female patients, and sperm banking for male patients. The OCP protocol consists of aspiration of oocytes from small antral follicles and in-vitro maturation followed by cryopreservation, as well as ovarian tissue cryopreservation. RESULTS: The establishment of a designated FP program resulted in a significant increase in referral and subsequent FP procedures of all eligible patients. Sixty-two female patients were referred for FP discussion during a period of 36 months; 41 underwent OCP; 11 underwent oocyte cryopreservation and six were declined due to parental decision. The median age was 13.2y (range 18 months-18y). Thirty-two (51.6 %) were chemotherapy-naïve. Seventeen patients (27 %) had sarcoma, 16 patients (26 %) had acute leukemia. The mean number of mature oocytes that were eventually vitrified was significantly higher in chemotherapy-naïve patients compared with chemotherapy-exposed patients (mean 12 oocytes (1-42) versus 2 (0-7)). CONCLUSION: Multidisciplinary programs that encompass experts of all relevant fields, skilled laboratory resources and a facilitated path appear to maximize the yield. We observed a considerable higher referral rates following launching a designated program and earlier OCP in chemo-naïve patients that culminated in a better fertility preservation procedure.

Cryopreservation of in vitro matured oocytes in addition to ovarian tissue freezing for fertility preservation in paediatric female cancer patients before and after cancer therapy.

STUDY QUESTION: Is a protocol that combines in vitro maturation of germinal vesicle-stage oocytes and their vitrification with freezing of cortical ovarian tissue feasible for use in fertility preservation for both chemotherapy-naive paediatric patients as well as patients after initiation of cancer therapy? SUMMARY ANSWER: Follicle-containing ovarian tissue as well as oocytes that can undergo maturation in vitro can be obtained from paediatric patients (including prepubertal girls) both before and after cancer therapy. WHAT IS KNOWN ALREADY: Anticancer therapy reduces the number of follicles/oocytes but this effect is less severe in young patients, particularly the paediatric age group. Autotransplantation of ovarian tissue has yielded to date 60 live births, including one from tissue that was cryostored in adolescence. However, it is assumed that autografting cryopreserved-thawed ovarian cortical tissue poses a risk of reseeding the malignancy. Immature oocytes can be collected from very young girls without hormonal stimulation and then matured in vitro and vitrified. We have previously shown that there is no difference in the number of ovarian cortical follicles between paediatric patients before and after chemotherapy. STUDY DESIGN, SIZE, DURATION: A prospective study was conducted in a cohort of 42 paediatric females with cancer (before and after therapy initiation) who underwent fertility preservation procedures in 2007-2014 at a single tertiary medical centre. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study group included girls and adolescent females with cancer: 22 before and 20 after chemotherapy. Following partial or complete oophorectomy, immature oocytes were either aspirated manually ex vivo from visible small antral follicles or filtered from spent media. Oocytes were incubated in oocyte maturation medium, and those that matured at 24 or 48 h were vitrified. Ovarian cortical tissue was cut and prepared for slow-gradual cryopreservation. Anti-Mullerian hormone (AMH) levels were measured in serum before and after oophorectomy. MAIN RESULTS AND ROLE OF CHANCE: Ovarian tissue was successfully collected from 78.7% of the 42 patients. Oocytes were obtained from 20 patients before chemotherapy and 13 after chemotherapy. The youngest patients from whom oocytes were retrieved were aged 2 years (two atretic follicles) and 3 years. Of the 395 oocytes collected, ∼30% were atretic (29.6% in the pre-chemotherapy group, 37% in the post-chemotherapy group). One hundred twenty-one oocytes (31%) were matured in vitro and vitrified: 67.8% from patients before chemotherapy, the rest after chemotherapy. Mature oocytes suitable for vitrification were obtained from 16/20 patients before chemotherapy and from 12/13 patients after chemotherapy (maturation rate, 32 and 26.4%, respectively). There were significant correlations of the number of vitrified oocytes with patient age (more matured oocytes with older age) (P = 0.001) and with pre-oophorectomy AMH levels (P = 0.038 pre-chemotherapy group, P = 0.029 post-chemotherapy group). Oocytes suitable for vitrification were obtained both by manual aspiration of antral follicles (45%) and from rinse solutions after dissection. There were significantly more matured oocytes in the pre-chemotherapy group from aspiration than in the post-chemotherapy group after both aspiration (P < 0.033) and retrieval from rinsing fluids (P < 0.044). The number of pre-antral follicles per histological section did not differ in the pre- versus post-chemotherapy. AMH levels dropped by approximately 50% after ovarian removal in both groups, with a significant correlation between pre- and post-oophorectomy levels (P = 0.002 pre-chemotherapy group, P = 0.001 post-chemotherapy group). LIMITATIONS, REASONS FOR CAUTION: There were no patients between 5 years and 10 years old in the post-chemotherapy group, which might have affected some results and correlations. Oocytes from patients soon after chemotherapy might be damaged, and caution is advised when using them for fertility-restoration purposes. The viability, development capability and fertilization potential of oocytes from paediatric patients, especially prepubertal and after chemotherapy, are unknown, in particular oocytes recovered from the media after the tissue dissection step. WIDER IMPLICATIONS OF THE FINDINGS: Although more oocytes were collected and matured from chemotherapy-naïve paediatric patients, ovarian tissue and immature oocytes were also retrieved from young girls in whom cancer therapy has already been initiated. Our centre has established a protocol for potential maximal fertility preservation in paediatric female patients with cancer. Vitrified-in vitro-matured oocytes may serve as an important gamete source in paediatric female patients with cancer because the risk of reseeding the disease is avoided. Further studies are needed on the fertility-restoring potential of oocytes from paediatric and prepubertal patients, especially after exposure to chemotherapy. STUDY FUNDING/COMPETING INTERESTS: The study was conducted as part of the routine procedures for fertility preservation at our IVF unit. No funding outside of the IVF laboratory was received. Funding for the AMH measurements was obtained by a research grant from the Israel Science Foundation (to B.-A.I., ISF 13-1873). None of the authors have competing interests. TRIAL REGISTRATION NUMBER: N/A.

Role of imaging in the diagnosis of acute appendicitis in children.

The aim of the study was to investigate the place of imaging in the diagnosis and treatment of acute appendicitis. The files of 2,427 children with suspected acute appendicitis were reviewed for clinical management and operative findings. The sample was divided into 3 groups at time of admission: (1) before diagnostic imaging was available in our department (1991-1994); (2) after the introduction of imaging studies on a random basis in equivocal cases (1995-1998); and (3) after a policy was formulated for ultrasound use in all equivocal cases followed by computed tomography if necessary (1999-2000). Results showed that the rate of misdiagnosis decreased from 13.2% in group 1 to 6.5% in group 2 and 6.1% in group 3. False-positive findings (normal appendix with positive scan) were noted in 16.7% of group 2 and 25% of group 3; false-negative findings (appendicitis at surgery with negative scan) in 23.8% and 9.5%, respectively. Computed tomography was performed in 8 children and prevented unnecessary surgery in 4 of them. We conclude that in equivocal cases of acute appendicitis, imaging studies performed by skilled operators can improve the accuracy of diagnosis, saving patients unnecessary surgery, and identifying other conditions that mimic appendicitis.

Urogenital abnormalities in male children with cystic fibrosis.

BACKGROUND: Congenital bilateral absence of the vas deferens (CBAVD) is presumed to occur prenatally and is present in over 99% of adult males with cystic fibrosis (CF). AIMS: To describe ultrasonic features in male children with CF. We aimed to describe urogenital anomalies, comparing pancreatic sufficient and insufficient CF patients. METHODS: Pelvic and scrotal ultrasonography were performed in 12 boys with CF aged 2-12 years and 16 age matched healthy controls. RESULTS: Nine patients had pancreatic insufficiency (PI): seven had two severe mutations and two had unknown mutations. Three boys were pancreatic sufficient (PS), two with splicing mutations (5T and 3849+10kb C-T respectively) and borderline sweat tests. Seminal vesicles were visualised in 5/12 patients and 8/16 controls, compared to non-visualisation reported in all adults with CBAVD. Testicular microlithiasis was found in 4/18 PI, 0/6 PS, and 0/32 control testes, compared to 0.6-1.4% in healthy males and 15% in CF adults; 7/18 PI, 4/6 PS, and 0/32 control testes were smaller than predicted for age. The epididymal head was non-homogeneous with cysts, hypo-, or hyper-echogenicity in 5/18 PI, 1/6 PS, and 0/32 control testes. CONCLUSIONS: Genital abnormalities may occur early in CF, but are less common than described in adults. They are found more often in pancreatic insufficient than in pancreatic sufficient CF patients. However, a positive finding, if present, may aid in the diagnosis of the latter. A larger longitudinal study is recommended to better define the onset and progression of urogenital abnormalities.

Mediastinal tumors in children: a single institution experience.

Mediastinal masses in children are a heterogeneous group of asymptomatic or potentially life-threatening congenital, infectious, or neoplastic lesions that present complex diagnostic and therapeutic dilemmas. Some patients are asymptomatic; in others, the mass may compress mediastinal structures and cause sudden asphyxia. In these cases, close cooperation is needed among pediatric surgeons, anesthesiologists, intensivists, oncologists, and radiologists. The files of 45 children with mediastinal masses admitted between 1986 and 1999 to the Pediatric Intensive Care Unit (PICU) of Schneider Children's Medical Center of Israel were reviewed. Twenty-one were admitted for perioperative care, and 21 for emergency care, including 19 with respiratory distress. Five of the emergency care group had asphyxia and 10 needed assisted ventilation. Two children were admitted for evaluation and 1 for leukopheresis. The children admitted on an emergency basis had more clinical findings than the postoperative group: almost 80% had dyspnea and more than 45% had oxygen desaturation; 33% had cough and noisy breathing, and 25%, superior vena cava syndrome or hepatosplenomegaly. Eight patients (17.8%) had benign disease and 37 (82.2%) malignant disease. The patients with a benign mass were significantly younger than the patients with a malignant mass (p<0.005); in 5 cases (12.5%), a congenital anomaly presented as a mediastinal mass. Most of the malignant masses were of hematologic origin (40.5%), followed by neurogenic tumors (27%). Twenty-seven patients underwent surgery, including 6 emergency procedures (3 partial resections, 2 biopsies, 1 lymph node biopsy). There were no intraoperative or postoperative deaths. The present series emphasizes the complex care children with a mediastinal mass require. They should be treated in a tertiary center with a multidisciplinary approach.

Skin level division of percutaneous endoscopic gastrostomy without endoscopy retrieval: a hazardous procedure.

Percutaneous endoscopic gastrostomy (PEG) has become the method of choice for long-term enteral access in the pediatric population. Since its introduction, several common complications have been described. Less well known is the danger of removing or replacing a PEG by cutting the device at skin level without endoscopic assistance to ensure the complete removal of all parts. The aim of the present work is to describe a patient in whom gastrostomy parts were retained after PEG removal, causing bowel obstruction and perforation.

Quadriceps paresis in pediatric groin surgery.

A total of 2,624 groin operations were performed in 2,202 infants and children aged 6 months-14 years during the last 4.5 years. Preventive analgesia was used in all operations, and included ilioinguinal and iliohypogastric nerve block combined with inguinal canal infiltration. In 6 patients transient postoperative quadriceps muscle paresis (QMP) was noted. They required bed rest and monitoring for a few hours, and complete spontaneous recovery was noted in all cases. The aim of this study was to examine the incidence of transient QMP following regional nerve block and to discuss models of possible prevention.

The distal pouch in esophageal atresia -- to dissect or not to dissect, that is the question.

Long-gap esophageal atresia remains a difficult problem for the pediatric surgeon and reconstruction using the native esophagus is considered to be superior to any interposition procedure. Because of esophageal segmental blood supply and vascular vulnerability of the distal esophageal pouch in the short term and its motility disorder in the long term, surgeons are reluctant to perform extensive esophageal dissection. However, ascending and descending branches of esophageal vessels converge along the anterolateral and posterolateral aspects of the esophagus. This arrangement allows for dissection and mobilization of the distal pouch without necessarily causing vascular impairment. Extensive dissection of the distal pouch was advocated by Robert Gross over fifty years ago. More recently, circular myotomy of the distal pouch has been performed. However, manometric studies showed that prior to surgical repair, peristalsis of the upper and lower esophageal pouch was synchronized, while after surgery this coordination was clearly defective. Furthermore, in the adriamycin-induced rat model, inherent abnormalities in the course and branching pattern of the vagus nerves in the lower esophagus have been demonstrated. Significant abnormalities of the intramural nervous components involving both the excitatory and inhibitory nerves, and elevated levels of S100 and galanin in the lower esophageal pouch could explain an inborn motility disorder. The selective injury of minor vagal branches in experimental animals also alters esophageal peristalsis. In conclusion, given that the native esophagus is still considered the best alternative for reconstruction of esophageal atresia, when indicated, gentle but extensive dissection of the lower esophageal pouch seems to be preferable, keeping in mind the possibility of vascular compromise and the inevitability of motility disfunction.

Volvulus of the stomach in childhood: the spectrum of the disease.

INTRODUCTION: During a 5-year time frame, five cases of symptomatic gastric volvulus were diagnosed and treated in our department. Four presented with the acute form of gastric volvulus and underwent emergency surgery. The fifth suffered the chronic variant of the syndrome and was benefited by nonoperative management. The cases serve to remind emergency physicians of the spectrum of gastric volvulus. The report supplements the sparse clinical description in the emergency literature. RESULTS: In the operated patients, there were no postoperative complications. The outcome, to the time of publication, has been good in every instance. The history, etiology, presentation, and treatment of the disease are discussed in detail. CONCLUSIONS: Not infrequently, gastric volvulus in children fails to exhibit the full gamut of signs and symptoms such as abdominal distension, vomiting, pain, and retching. For this, as well as for other stated reasons, symptomatic gastric volvulus in infancy and childhood may not be as rare as is commonly assumed.

Successful intraperitoneal nutrition in rabbits with short-bowel syndrome.

The efficacy of intraperitoneal alimentation as a means of nutritional support for various degrees of short-bowel syndrome was studied, using the rabbit model. Twenty-eight rabbits were divided into 5 groups. Group I had a sham operation; Groups II, III and IV had 50 %, 75 % and 90 % small-bowel resections (SBR), respectively; Group V had a 90 % SBR with intraperitoneal nutrition. All the rabbits received a regular diet and tap water post-operatively. The rabbits in Group V received intraperitoneal alimentation (IPA) by way of a peritoneal catheter inserted at the time of surgery. The nutrition consisted of 10 % dextrose with 5.5 % amino acids. This provided 30 - 35 kcal/kg of additional energy per day. All the rabbits within Group IV (90 % resection without IP nutrition) died within 2 to 5 weeks. IP nutrition enabled body weight to be maintained and prevented the death of all rabbits with 90 % small-bowel resection.

Insights from animal models for growing intestinal neomucosa with serosal patching--a still untapped technique for the treatment of short bowel syndrome.

The aim of surgical treatment of short bowel syndrome is to increase the intestinal absorptive capacity by increasing the area of absorption or by slowing intestinal transit. The use of serosal patching to grow new intestinal mucosa is a technique for enlarging the intestinal surface. The regenerated intestine develops by lateral ingrowth from the neighbouring mucosa and is functionally similar to normal intestinal mucosa. The present review summarizes the main contributions of the rabbit, the rat and the canine models used to date for growing neomucosa using the serosal patch technique, as well as examining the influence of some growth factors on the development of neomucosa.

A simple method of intraoperative confirmation of intestinal patency.

Routine intraoperative rectal temperature monitoring may serve in addition as a means of distal intestinal patency confirmation. A simple method, which is of immense importance especially when operating on infants and small children after NEC or intestinal atresia, is described.

Traumatic adrenal injury in children.

BACKGROUND: Multiple organ injury in children is an increasingly frequent phenomenon in the modern emergency room. Adrenal hemorrhage associated with this type of trauma has received little attention in the past. OBJECTIVES: Using computed tomography, we sought to determine the rate and nature of adrenal gland injury in children following blunt abdominal trauma due to motor vehicular accident. METHODS: A total of 121 children with blunt abdominal trauma were examined and total body CT was performed in cases of multi-organ trauma or severe neurological injury. RESULTS: Of all the children who presented with blunt abdominal trauma over a 51 month period, 6 (4.95%) had adrenal hemorrhage. In all cases only the right adrenal gland was affected. Coincidental injury to the chest and other abdominal organs was noted in 66.7% and 50% of patients, respectively. CONCLUSIONS: Traumatic adrenal injury in the pediatric population may be more common than previously suspected. Widespread application of the more sophisticated imaging modalities available today will improve the detection of damage to the smaller organs in major collision injuries and will help in directing attention to the mechanism of trauma.

Decreased insulin-like growth factor-I receptor sites on circulating mononuclear cells from children with acute leukemia.

Insulin-like growth factor-I (IGF-I) is a known mitogen for various cell types, including those of the hematopoietic cell system. To study the role of IGF-I in the neoplastic process of leukemia in children, the authors have determined the number of IGF-I binding sites on circulating mononuclear cells of children with acute leukemia as compared to normal children, using binding assays. The IGF-I binding sites per cell on peripheral mononuclear cells of children with leukemia decreased compared to those of the control group (411 +/- 73 and 1334 +/- 227, respectively, p < .001), while their affinity increased (Kd = 0.14 +/- 0.04 and 0.43 +/- 0.16, respectively, p = .05). Furthermore, in the patients, the number of the IGF-I binding sites was significantly lower in the subgroup of the peripheral mononuclear cells, which included lymphocytes and monocytes, as compared to their number in the peripheral blast cells (254 +/- 43.6 and 536 +/- 98.6, respectively, p = .02). A significant reduction was found in serum GHBP levels in the patients as compared to the controls (28.21 +/- 1.93 and 35.83 +/- 2.90, respectively, p = .02), while serum IGF-I and growth hormone levels were similar in patient and control groups. These results suggest a possible involvement of IGF-I in childhood acute leukemia, but further studies are needed to establish whether IGF-I plays a role in this disease.

High frequency of loss of heterozygosity for 1p35-p36 (D1S247) in Wilms tumor.

We analyzed the loss of heterozygosity (LOH) for 1p in 18 Wilms tumors using a panel of 11 polymorphic markers. Loss of heterozygosity was identified in 56% of the tumors. The smallest region of overlap was defined for marker D1S247, underlying the 1p35-1p36.1 locus. This is the highest LOH frequency for 1p, or for the well-defined 11p13 and 11p15.5 loci. Based on the fact that tumors of all stages, with both favorable and unfavorable histology, exhibited LOH, we suggest that the 1p35-1p36.1 locus is involved in the etiology of Wilms tumor.

Minimally invasive surgery in pediatric endocrinology.

The use of minimally invasive surgery (MIS) in children and adolescents is steadily increasing. The aim of the present review was to summarize the status of MIS in pediatric endocrinology. We found that laparoscopic procedures have been proven useful for the diagnosis or treatment of endometriosis and its associated manifestations, undescended testicles, ambiguous genitalia, adnexal torsion and ovarian cyst. Considering the safety and efficacy of these applications, the more rapid recovery of the patients, and the considerably less pain induced, we believe MIS will gradually take precedence over standard procedures in many areas of endocrinology in the young population.