Skeletal Analysis of the Long Bone Abnormality (lbab/lbab) Mouse, A Novel Chondrodysplastic C-Type Natriuretic Peptide Mutant

Long bone abnormality (lbab/lbab) is a strain of dwarf mice. Recent studies revealed that the phenotype is caused by a spontaneous mutation in the Nppc gene, which encodes mouse C-type natriuretic peptide (CNP). In this study, we analyzed the chondrodysplastic skeletal phenotype of lbab/lbab mice. At birth, lbab/lbab mice are only slightly shorter than their wild-type littermates. Nevertheless, lbab/lbab mice do not undergo a growth spurt, and their final body and bone lengths are only ~60% of those of wild-type mice. Histological analysis revealed that the growth plate in lbab/lbab mice, especially the hypertrophic chondrocyte layer, was significantly thinner than in wild-type mice. Overexpression of CNP in the cartilage of lbab/lbab mice restored their thinned growth plate, followed by the complete rescue of their impaired endochondral bone growth. Furthermore, the bone volume in lbab/lbab mouse was severely decreased and was recovered by CNP overexpression. On the other hand, the thickness of the growth plate of lbab/+ mice was not different from that of wild-type mice; accordingly, impaired endochondral bone growth was not observed in lbab/+ mice. In organ culture experiments, tibial explants from fetal lbab/lbab mice were significantly shorter than those from lbab/+ mice and elongated by addition of 10⁻⁷ M CNP to the same extent as lbab/+ tibiae treated with the same dose of CNP. These results demonstrate that lbab/lbab is a novel mouse model of chondrodysplasia caused by insufficient CNP action on endochondral ossification.     

Extraperitoneal laparoscopic retroperitoneal lymph node dissection after chemotherapy for nonseminomatous testicular germ-cell tumor: surgical and oncological outcomes

Purpose

To assess the surgical and oncological outcomes of laparoscopic retroperitoneal lymph node dissection (RPLND) after chemotherapy.

Methods

Twenty patients with metastatic nonseminomatous testicular germ-cell tumor underwent extraperitoneal laparoscopic RPLND after chemotherapy. The procedure was not indicated for patients with a pre-chemotherapy mass larger than 5?cm. Morbidity and oncological outcome were reviewed retrospectively. Surgical complications were graded according to the Clavien classification system.

Results

Laparoscopic RPLND was completed in all patients, and there was no conversion to open surgery. The median operating time was 223?min (range, 137?C399?min). The median blood loss was 20?ml (range, 10?C520?ml). There were no intraoperative complications. Postoperatively, 4 patients (20?%) had prolonged lymphorrhea (grade I) and 9 (45?%) had chyle leakage (grade I). Histological examination of the residual mass revealed necrosis in 16 (80?%) and the presence of teratoma with/without viable tumor in 4 (20?%). With a median follow-up of 45?months (range, 24?C112), no patient has had disease recurrence. Normal antegrade ejaculation was preserved in all of the 14 patients studied.

Conclusions

Extraperitoneal laparoscopic RPLND can be performed with acceptable morbidity and excellent cancer control in select patients. Surgeons should be aware of relatively high incidence of chyle leakage following this procedure.     

Laparoscopic transabdominal preperitoneal inguinal hernia repair using needlescopic instruments: a 15-year, single-center experience in 317 patients

Background

Laparoscopic inguinal hernia repair is associated with a decrease in postoperative pain, shortened hospital stay, earlier return to normal activity, and decrease in chronic pain. Moreover, laparoscopic surgery performed with needlescopic instruments has more advantages than conventional laparoscopic surgery. However, there are few reports of large-scale laparoscopic transabdominal preperitoneal inguinal hernia repair using needlescopic instruments (nTAPP). This report reviews our experiences with 352 nTAPP in 317 patients during the 15-year period from April 1996 to April 2011.

Methods

We performed nTAPP as the method of choice in 88.5% of all patients presenting with inguinal hernia. To perform the nTAPP, 3-mm instruments were used. A 5-mm laparoscope was inserted from the umbilicus, and surgical instruments were inserted through 5- and 3-mm trocars. After reduction of the hernia sac and dissection of the preperitoneal space, we placed polyester mesh or polypropylene soft mesh with staple fixation. The peritoneum was closed with 3–0 silk interrupted sutures.

Results

The mean operative time was 102.9?min for unilateral hernias and 155.8?min for bilateral hernias. There was no conversion to open repair. Forty-three patients (13.6%) used postoperative analgesics, and the mean frequency of use was 0.5 times. Regarding intraoperative complications, we observed one bladder injury, but no bowel injuries or major vessel injuries. Postoperative complications occurred in 32 patients (10.1%). One patient with a retained lipoma required reoperation. There was no incidence of chronic pain or mesh infection. The operative time for experienced surgeons (≥20 repairs) was significantly shorter than that of inexperienced surgeons (<20 repairs; P?Conclusions The nTAPP was a safe and useful technique for inguinal hernia repair. Large prospective, randomized controlled trials will be required to establish the benefit of nTAPP.     

CT-guided radiofrequency ablation of osteoid osteoma in the long bones of the lower extremity

AIM:To present our initial experience with computed tomography guided radiofrequency ablation(RFA) of osteoid osteoma(OO) in our institution.METHODS:RFA was performed on eight patients(5 males and 3 females) with clinically and radiologically diagnosed OO(femoral neck,n = 4;femoral diaphysis,n = 2;tibial diaphysis,n = 1;fibular diaphysis,n = 1).Ablation was performed using an electrode with a 10-mm exposed tip for a total of 4-6 min at a targeted temperature of 90 degrees Celsius.No cooling system was used.The intervention was accepted as technically successful if the tip of the electrode could be placed within the center of the nidus.We defined clinical success as a disappearance within 2 wk after treatment of symptoms that had manifested at presentation.RESULTS:All procedures were technically successful.No major or immediate complications were observed.Clinical success was achieved in six of eight patients in the first procedure.A second procedure was performed for two patients who had recurrent or continued pain,and one of these cases was successfully treated.The overall rate of success was 87.5%(7/8).No complication was observed.CONCLUSION:Our preliminary results indicate a favorable success rate and no complications and are compatible with the previous reports of RFA of OO.     

Convulsive Liability of Cefepime and Meropenem in Normal and Corneal Kindled Mice

We have reported significantly higher convulsion prevalence in patients treated with cefepime than in those treated with meropenem. Additionally, cefepime-associated convulsions were found only in patients with brain disorders, not renal failure. Here, we compared the convulsive liability of cefepime and meropenem administered intravenously in normal and corneal kindled mice with low seizure thresholds. We used the proconvulsive test in normal mice following pentylenetetrazol (PTZ) injection and electroconvulsive shock at low-stimulus currents and in corneal kindled mice. We also measured electroencephalogram (EEG) activity 1 min after antibiotic injections. Intravenous injection of cefepime and meropenem at 250 or 500 mg/kg of body weight had no effect on PTZ-induced convulsions in normal mice. However, in convulsions induced by electroconvulsive shock at low-stimulus currents, mean seizure stage following cefepime administration at 500 mg/kg was significantly higher than that following saline injection. Additionally, EEG spikes were recorded for mice that were given cefepime (500 mg/kg). In corneal kindled mice following cefepime injection, mean seizure stage was significantly higher than that following meropenem injection. The convulsive liability of cefepime is significantly higher than that of meropenem in normal and corneal kindled mice. In patients with low seizure thresholds, convulsive liability of cefepime may be assumed.     

Dosimetry of radon progeny deposited on skin in air and thermal water

It is held that the skin dose from radon progeny is not negligibly small and that introducing cancer is a possible consequence under normal circumstances as there are a number of uncertainties in terms of related parameters such as activity concentrations in air and water, target cells in skin, skin covering materials, and deposition velocities. An interesting proposal has emerged in that skin exposure to natural radon-rich thermal water as part of balneotherapy can produce an immune response to induce beneficial health effects. The goal of this study was to obtain generic dose coefficients with a focus on the radon progeny deposited on the skin in air or water in relation to risk or treatment assessments. We thus first estimated the skin deposition velocities of radon progeny in air and thermal water based on data from the latest human studies. Skin dosimetry was then performed under different assumptions regarding alpha-emitting source position and target cell (i.e. basal cells or Langerhans cells). Furthermore, the impact of the radon progeny deposition on effective doses from all exposure pathways relating to ‘radon exposure’ was assessed using various possible scenarios. It was found that in both exposure media, effective doses from radon progeny inhalation are one to four orders of magnitude higher than those from the other pathways. In addition, absorbed doses on the skin can be the highest among all pathways when the radon activity concentrations in water are two or more orders of magnitude higher than those in air.     

Prevalence of cerebral aneurysm in patients with acromegaly

The prevalence of cerebral aneurysm was retrospectively investigated in 208 patients with acromegaly relative to the rate of cerebral aneurysm in a group of control subjects. Neuroradiological examinations of the cerebral vascular system were conducted in 208 acromegaly patients (101 men; mean age, 48.8 years). The prevalence of cerebral aneurysm in the acromegaly patients was compared to that in a control group consisting of 7,390 subjects who underwent “brain checkup” between 2006 and 2008 (mean age, 51.6 years). In the acromegaly group, cerebral aneurysm was detected in 4.3 % of patients. By sex, the prevalence was 6.9 % in males, a significantly proportion than that in the control group with an odds ratio of 4.40. The prevalence in females did not differ between the two groups. In the acromegaly group, the rate of hypertension was significantly higher in the patients with aneurysm compared to those without aneurysm. Multiple logistic regression identified acromegaly as a significant factor related to the prevalence of cerebral aneurysm in all male subjects; other factors, such as age, hypertension and smoking, were not found to be significant. A significantly higher prevalence of cerebral aneurysm was detected in male patients with acromegaly. This finding indicates that excess growth hormone or insulin-like growth factor 1 affects the cerebral vascular wall, resulting in aneurysm formation. In addition to known systematic complications in the cardiovascular, respiratory, metabolic, and other systems, the risk of cerebral aneurysm should be considered in the management of acromegaly.