The role of the testicular factor INSL3 in establishing the gonadal position

INSL3, also designated Leydig insulin-like (Ley I-L) or relaxin-like factor (RLF), belongs to the insulin-like hormone superfamily. It is expressed in pre- and postnatal Leydig cells of the testis and in postnatal theca cells of the ovary. This sexual dimorphic pattern of INSL3 expression during development led us to suggest that the INSL3 factor could play an essential role in sexual differentiation, gonadal function and germ cell development. Key insights into the role of INSL3 came from analyses of INSL3 knockout mice. These mice showed impaired development of the gubernaculum ligament, a structure that is believed to mediate transabdominal descent of the testis during male embryogenesis. In double mutant XY-mice lacking INSL3 and a functional androgen receptor, it was demonstrated that both are essential for establishment of the sexual dimorphic position of the gonads through regulation of gubernaculum development and regression of the cranial suspensory ligament (CSL) during fetal life. Defects in this developmental process can cause cryptorchidism in the male, which is a most common disorder of sexual differentiation in human.     

Nematode infection: A rare mimic of acute appendicitis

INTRODUCTION

Acute appendicitis is a common condition seen in all surgical units. One rare condition that can mimic acute appendicitis is a nematode infection of the bowel. There have been few reported cases of nematode infection within the appendix and none that have been accompanied by intra-operative pictures.

PRESENTATION OF CASE

A 16-year-old female presented with a 12 h history of right iliac fossa pain and mild pyrexia. Bloods showed a neutrophilia and normal C-reactive protein. Laparoscopy was performed which revealed a non-inflamed appendix. The appendix was dissected and a live nematode was visualised exiting the base of the appendix. Anti-helminthics were given and the infection resolved.

DISCUSSION

Nematode infection is most commonly seen in Africa, Asia and South America. When seen within the United Kingdom (UK), it is seen most commonly within high-risk populations. Testing for these infections is not routine within the UK and when they are performed, the results take a considerable amount of time to return. These tests should be considered within high-risk populations so that unnecessary surgery can be avoided.

CONCLUSION

This case highlights the importance of considering rare causes of right iliac fossa pain including nematode infection in a young patient. The case highlights this by giving intra-operative pictures of live nematodes upon dissection of the appendix.     

Evaluation of two dental registration-splint techniques for surgical navigation in cranio-maxillofacial surgery

BackgroundSurgical navigation requires precise registration of the pre-operative image dataset to the patient in the operation theatre. Different marker-based and marker-free registration techniques are available, each of them with advantages and disadvantages regarding precision and clinical handling. In this model study, the precision of two dental splint techniques for marker-based registration is analyzed.Materials and methodsA synthetic full-size human skull was registered with its cone beam computed tomography dataset using (a) a dentally-mounted “rapid” occlusal splint with five titanium screws directly attached to the splint, (b) an “extender”, a dentally-mounted occlusal splint with similar fiducials fixed to an extension of the splint. The target registration error was measured for 170 landmarks distributed over the viscero- and neurocranium in 10 repeats per splint type using the Vector Vision² (BrainLAB AG, Heimstetten, Germany) navigation system. Statistical and graphical evaluations were performed per anatomical region.ResultsIn the periorbital region, the rapid splint, with an average deviation of 1.50 mm (SD = 0.439) showed greater accuracy than the extender with 1.76 mm (SD = 0.525). The viscerocranial results for both splints were similar (extender 1.84 mm, SD = 0.559, rapid occlusal splint 1.86 mm, SD = 0.686). In the cranial vault region, registration with the extender (2.33 mm, SD = 0.685) proved to be more precise than with the rapid splint (2.86 mm, SD = 0.929).ConclusionsDue to the more compact dimension of the rapid occlusal splint, errors close to the splint were smaller compared to the extender technique. The advantage of greater distances between the registration fiducials on the extender is particularly important in areas such as the orbital roof, the cranial vault, and the lateral skull base.     

Thinning or dehiscence of bone in structures of the middle cranial fossa floor in superior semicircular canal dehiscence

BackgroundSuperior semicircular canal dehiscence (SSCD) is a rare inner ear disorder; currently, it is unknown whether the etiopathology underlying this structural irregularity affects neighboring structures. The goal is to investigate the prevalence of bone thinning in areas of the middle cranial fossa (MCF) floor in SSCD and non-SSCD patients.MethodsThis retrospective study analyzed 100 patients from March 2011 to June 2017 at a tertiary referral center. 100 patients undergoing 118 SSCD repair surgeries (18 bilateral) were identified. 12 SSCD ears were excluded due to lack of pre-operative computed tomography (CT) scans or history of prior SSCD repair at an outside facility. Non-SSCD ears were identified from routinely-obtained CT scans for temporal bone fracture (fractured sides excluded) for a total of 101 ears; 26 non-SSCD ears were excluded due to lack of high-resolution imaging.ResultsUnivariate analyses reveal that SSCD diagnosis is associated with higher rates of geniculate ganglion (GG) dehiscence compared with non-SSCD controls (42.7 vs. 24%; χ ² (1) = 9.69, P = 0.008). Individuals with SSCD depicted significantly thinner bone overlying the geniculate ganglion (GG) (0.23 ± 1.2 mm) compared to controls (0.28 ± 1.8 mm, (t(1 6 4)) = 2.1, P = 0.04). SSCD patients presented thinner bone overlying the internal auditory canal (IAC) (0.33 ± 1.3 mm) compared to patients without SSCD (0.46 ± 1.6 mm, (t(2 5 7) = 6.4, P < 0.001).ConclusionsThe increased prevalence of dehiscence of the MCF in this cohort of SSCD patients compared to non-SSCD patients suggests that the etiology underlying SSCD affects surrounding structures.     

神经内镜辅助夹闭颅内动脉瘤临床研究

目的 探讨神经内镜辅助夹闭颅内动脉瘤的价值。方法 2000年2月至2002年12月，神经内镜辅助颅内动脉瘤手术夹闭78例患79个动脉瘤，前循环系统动脉瘤72例(73个动脉瘤)，后循环系统动脉瘤6例。动脉瘤体直径5—40mm，平均12．5mm。术前分级：Hunt—Hess分级0级8例，Ⅰ级32例，Ⅱ级33例，Ⅲ级5例。结果 本组无手术死亡，手术后出现并发症6例(7．7％)，其中肢体偏瘫4例(1例合并语言障碍)，伪膜性肠炎及视力下降各1例。本组未出现与内镜有关的并发症。结论 神经内镜辅助动脉瘤外科提高了手术效果，但神经内镜设备仍有待改进。     

术中窦汇区迟发性硬膜外血肿致急性脑膨出的治疗

目的 探讨颅脑损伤患者术中窦汇区迟发性硬膜外血肿所致急性脑膨出的临床特点及诊治经验.方法 回顾我院2007年5月至2009年5月收治的10例颅脑损伤患者,均为开颅术中发现急性脑膨出,术中复查头颅CT明确窦汇区迟发性硬膜外血肿的诊断后,取顶枕部"U"形切口,做窦汇区骨瓣成形加自体筋膜加压修补术.结果 根据GOS评分判断愈后:中残2例,重残1例,植物生存1例,死亡6例.结论 窦汇区硬膜外血肿做跨窦骨瓣成形术,骨瓣足够大,出血点完全暴露,再用自体筋膜加压修补术彻底止血,是理想的手术方法 .早期诊断及正确的手术方法 是救治成功的关键.