Laparoscopic liver resection as a treatment option for intrahepatic cholangiocarcinoma

Laparoscopic liver resection (LLR) remains controversial in the treatment of intrahepatic cholangiocarcinoma (ICC). The aim of the present study is to investigate the outcomes of LLR for ICC compared to open liver resection (OLR). We retrospectively reviewed patients who underwent surgery for ICC between January 2013 and February 2020. OLR and LLR were compared after propensity score matching (PSM). Overall survival (OS) and recurrence-free survival (RFS) were compared between the matched groups. During the study period, 219 patients met the inclusion criteria (OLR = 170 patients, 77.6%; LLR = 49 patients, 22.4%). Two groups of 43 patients each were analyzed after PSM. The 5-year RFS and OS were 44.6% and 47.9% in the OLR group and 50.9% and 39.8% in the LLR group, respectively. Hospital stay and intensive care unit care were significantly shorter and lower in the LLR group than in the OLR group, respectively. Total postoperative complications and complication rates for those Clavien-Dindo grade 3 or higher were similar between the OLR group and the LLR group. Multiple tumors and lymph node metastases were predisposing factors for tumor recurrence and death in multivariate analysis. The present study suggests that LLR should be considered in selective ICC because of short hospitalization and similar oncologic outcome and overall survival.

Differentiation of malignant from benign ampullary strictures: A prediction nomogram based on MR imaging and clinical findings

PURPOSE

To construct a predictive nomogram based on contrast-enhanced magnetic resonance imaging (MRI) and clinical findings for differentiating malignant from benign ampullary strictures.

METHOD

In this retrospective study, 76 patients with ampullary strictures (51 benign and 25 malignant) who underwent contrast-enhanced MRI were enrolled. Imaging findings were evaluated independently by two abdominal radiologists who reached consensus. Clinical findings were also collected. Significant findings for malignant ampullary strictures were assessed by univariable and multivariable logistic regression analyses. Based on the results of multivariable analysis, a nomogram to differentiate malignant from benign ampullary strictures was developed and internally validated.

RESULTS

In multivariable analysis, presence of an ampullary mass (odds ratio [OR]: 8.42, p = 0.047), bulging ampulla (OR: 8.32, p = 0.033), diffusion restriction of the ampulla (OR: 42.76, p = 0.004) on MRI, and jaundice (OR: 12.41, p = 0.019) were significant predictors of malignant ampullary strictures. A predictive nomogram was constructed using these findings. Among them, diffusion restriction of the ampulla showed the highest OR and predictor score on the nomogram. The calibration plots for internal validation achieved strong agreement between the predicted probabilities and the actual rates of malignant ampullary strictures.

CONCLUSION

A combination of significant contrast-enhanced MRI and clinical findings of ampullary mass, bulging ampulla, diffusion restriction of the ampulla, and jaundice may be useful in the prediction of malignant ampullary stricture.

Necessity of induction agent modification for old age kidney transplant recipients

Background

Immunosenescence gradually deteriorates the function of the immune system, making elderly patients susceptible to infection, while reducing rejection of organ transplants. Therefore, age-adaptive immunosuppression is necessary in the elderly. We evaluated clinical outcomes such as rejection and infection rate when using basiliximab and rabbit anti-thymocyte globulin (r-ATG) as induction agents in elderly and young organ transplant recipients.

Methods

We retrospectively reviewed patients who underwent kidney transplantation (KT) between June 2011 and April 2019. We enrolled 704 adult KT patients and classified the patients into groups according to patient age. We compared the outcomes of infection and biopsy-proven acute rejection (BPAR) according to the type of induction agent (basiliximab and r-ATG [4.5 mg/kg]).

Results

The patient group included 520 recipients (74.6%) in the younger recipient group and 179 recipients (25.4%) in the older recipient group. When r-ATG was used as an induction agent, BPAR within 6 months occurred less (p = 0.03); however, infections within 6 months were higher in older recipients. Deaths due to infection were more common in older recipients (p = 0.003).

Conclusion

It may be necessary to use less intensive induction therapy for older recipients, of which dose reduction of r-ATG is one option.

Upper thigh skeletal muscle index predicts outcomes in liver transplant recipients

Purpose

The skeletal muscle index (SMI) at the L3 level is widely used to diagnose sarcopenia. The upper thigh (UT) also reflects changes in whole-body muscle mass, but no study has examined this using the UT to diagnose sarcopenia in liver transplantation (LT). This study aimed to determine an optimal cut-off value for UT-SMI and investigate how sarcopenia diagnosed by UT-SMI correlates with outcomes in LT recipients.

Methods

In this retrospective study of 332 LT patients from 2018 to 2020, we investigated the association between sarcopenia diagnosed by UT-SMI and patient outcomes after LT.

Results

The cut-off values for UT-SMI were 38.3 cm2/m2 for females (area under the curve [AUC], 0.927; P < 0.001) and 46.7 cm2/m2 for males (AUC, 0.898; P < 0.001). The prevalence of sarcopenia diagnosed by UT-SMI was 33.4% in our cohort. Patient and graft survival rates in the UT-SMI sarcopenia group were significantly poorer than those in the UT-SMI non-sarcopenia group (P < 0.001 and P < 0.001). UT-SMI was an independent prognostic factor for patient survival (hazard ratio [HR], 2.182; 95% confidence interval [CI], 1.183-4.025; P = 0.012) and graft survival (HR, 2.227; 95% CI, 1.054-4704; P = 0.036) in our multivariable Cox analysis.

Conclusion

We confirmed that sarcopenia diagnosed by UT-SMI is associated with outcomes in LT recipients. In addition, UT-SMI was identified as an independent prognostic factor for patient survival and graft survival. Therefore, UT-SMI could be a good option for CT-based evaluations of sarcopenia in LT recipients.

Effect of pre-operative radiation therapy on surgical outcome in retroperitoneal sarcoma

Background

A high rate of locoregional recurrence is one of the major difficulties in successful treatment of retroperitoneal sarcoma (RPS). Although pre-operative radiation therapy (RT) is considered a potential way to improve local recurrence, concerns about the associated treatment toxicity and risk of peri-operative complications need to be addressed. Hence, this study investigates the safety of pre-operative RT (preRTx) for RPS.

Methods

A cohort of 198 patients with RPS who had undergone both surgery and RT was analyzed for peri-operative complications. They were divided into three groups according to the RT scheme: (1) preRTx group, (2) post-operative RT without tissue expander, and (3) post-operative RT with tissue expander.

Results

The preRTx was overall well tolerated and did not affect the R2 resection rate, operative time, and severe post-operative complications. However, the preRTx group was associated with higher incidence of post-operative transfusion and admission to intensive care unit (p = 0.013 and p = 0.036, respectively), where preRTx was an independent risk factor only for the post-operative transfusion (p = 0.009) in multivariate analysis. The median radiation dose was the highest in preRTx group, although no significant difference was demonstrated in overall survival and local recurrence rate.

Conclusion

This study suggests that the preRTx does not add significant post-operative morbidity to the patients with RPS. In addition, radiation dose elevation is achievable with the pre-operative RT. However, a meticulous intra-operative bleeding control is recommended in those patients, and further high-quality trials are warranted to evaluate the long-term oncological outcomes.

The Role of Preoperative 18F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Retroperitoneal Sarcoma

¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) was used to predict pathologic grades based on the maximum standardized uptake value (SUVmax) in soft tissue sarcoma and bone sarcoma. In retroperitoneal sarcoma (RPS), the effectiveness of PET was not well known. This study was designed to investigate the association of SUVmax with histopathologic grade and evaluate the usefulness of ¹⁸F-FDG PET/CT before operation. Patients at Samsung Medical Center undergoing primary surgery for retroperitoneal sarcoma with preoperative ¹⁸F-FDG PET/CT imaging between January 2001 and February 2020 were investigated. The relationship between SUVmax and histologic features was assessed. The association of SUVmax with overall survival (OS), local recurrence (LR), and distant metastasis (DM) were studied. Of the total 129 patients, the most common histologic subtypes were liposarcoma (LPS; 68.2%) and leiomyosarcoma (LMS; 15.5%). The median SUVmax was 4.5 (range, 1- 29). Moreover, SUVmax was correlated with tumor grade (p < 0.001, Spearman coefficient; 0.627) and mitosis (p < 0.001, Spearman coefficient; 0.564) and showed a higher value in LMS (12.04 ± 6.73) than in dedifferentiated liposarcoma (DDLPS; 6.32 ± 4.97, p = 0.0054). SUVmax was correlated with pathologic parameters (tumor grade and mitosis) in RPS and was higher in the LMS group than the DDLPS group. The optimal SUVmax threshold to distinguish high tumor grade was 4.8. Those with a SUVmax greater than the threshold showed poor prognosis regarding OS, LR, and DM (p < 0.001).

Two-Week Protocol Biopsy in Renal Allograft: Feasibility, Safety, and Outcomes

Background: Protocol biopsy in renal allograft helps to early detect subclinical rejection (SCR) in patients who have no abnormal clinical and laboratory findings. Still, there are rare reports about the techniques and outcomes of two-week protocol biopsy. The aim of this study was to assess two-week protocol biopsy regarding the technical feasibility, procedure safety, and clinical outcomes. Methods: A total of 894 protocol biopsies were performed in adult recipients between 2012 and 2019. Two-week and one-year protocol biopsies were guided with ultrasound in 842 and 399 patients by one of four radiologists with wide range of biopsy experience, respectively. These protocol biopsies were compared in terms of feasibility and safety. Standard references were clinico-laboratory findings and biopsy examinations. Results: The median period of two-week and one-year protocol biopsies were 12 days (10–20 days) and 383 days (302–420 days), respectively. All protocol biopsies were technically successful and there was no difference between radiologists regarding technical success and complications (p = 0.453). Major complication (Clavien–Dindo grading II–IV) rates of two-week and one-year protocol biopsies were 0.3% (3/842) and 0.2% (1/399), respectively (p = 1.000). However, univariate analysis demonstrated that platelet count < 100 K/mL and blood urea nitrogen ≥ 40 mg/dL were associated with major complications in two-week protocol biopsy. The SCRs of these protocol biopsies were 15.4% (130/842) and 33.6% (134/399), respectively (p < 0.001). Conclusion: Two-week protocol biopsy is technically feasible and safe. It contributes to early detecting a substantial number of SCRs. Prior to the biopsy, platelet count and blood urea nitrogen should be carefully checked to predict major complications.

Recipient efficacy and safety of kidney transplantation from older living donor: consideration for using older kidney as a solution to the shortage of organs

Background

As a solution to organ shortages, studies on kidney transplantation (KT) from older donors are being conducted. However, many controversies remain about its safety and efficacy.

Methods

In Samsung Medical Center, from January 2000 to May 2015, 1,141 patients underwent living KT. Cases of retransplantation, recipient and donor aged younger than 18 years, and multiorgan transplantation were excluded, and a total of 859 cases were selected. Analysis was performed by dividing the patents into two groups a younger donor group (donors <60 years old; n=826) and an older donor group (donors ≥60 years old; n=33).

Results

There were no significant differences between the two groups in patient death (log-rank P=0.173) or in postoperative complications. The older donor group had a higher acute rejection (P=0.034; hazard ratio [HR], 1.704) and graft failure rate (P=0.029, HR=2.352). There was no significant difference in the trend of estimated glomerular filtration rate over time (P=0.189).

Conclusions

KT using kidneys from old-aged donors is safe, but there is room for improvement due to problems with higher acute rejection and graft failure rate.

Postoperative Outcomes of Distal Pancreatectomy for Retroperitoneal Sarcoma Abutting the Pancreas in the Left Upper Quadrant

Background

En bloc resection of the tumor with adjacent organs is recommended for localized retroperitoneal sarcoma (RPS). However, resection of the pancreas is controversial because it may cause serious complications, such as pancreatic fistula or bleeding. Thus, we evaluated the outcomes of distal pancreatectomy (DP) in pancreas-abutting RPS of the left upper quadrant (LUQ).

Methods

We retrospectively reviewed all consecutive patients who underwent surgery for RPS between September 2001 and April 2020. We selected 150 patients with all or part of their tumor located in the LUQ on preoperative computed tomography. Eighty-six patients who had tumors abutting the pancreas were finally enrolled in our study.

Results

Fifty-three patients (53/86; 61.6%) were included in the non-DP group, and 33 patients (33/86; 38.4%) were included in the DP group. Total postoperative complications and complication rates for those Clavien–Dindo grade 3 or higher were similar between the non-DP group and DP group (p = 0.290 and p = 0.550). In the DP group, grade B pancreatic fistulae occurred in 18.2% (6/33) of patients, but grade C pancreatic fistulae were absent, and microscopic pancreatic invasion was noted in 42.4% (14/33) of patients. During multivariate analysis, microscopic pancreatic invasion was deemed a risk factor for local recurrence (p = 0.029). However, there were no significant differences on preoperative computed tomography findings between the pancreatic invasion and non-invasion groups.

Conclusion

DP is a reasonable procedure for pancreas-abutting RPS located at the LUQ when both complications and complete resection are considered.

Cost-effectiveness and long-term outcomes of liver transplantation using hepatitis B core antibody-positive grafts with hepatitis B immunoglobulin prophylaxis in Korea

Background/Aims

Hepatitis B core antibody (anti-HBc)-positive donors are used as an extended donor pool, and current guidelines recommend the usage of nucleos(t)ide analogues (NAs) as prophylaxis for preventing de novo hepatitis B virus infection (DNH). We analyzed the long-term outcomes of a large cohort of liver transplantation (LT) patients receiving anti-HBc-positive grafts and evaluated the risk of DNH when hepatitis B immunoglobulin (HBIG) monotherapy was used as prophylaxis. We also compared the cost-effectiveness of HBIG and NAs.

Methods

We retrospectively reviewed 457 patients with anti-HBc-positive grafts and 898 patients with anti-HBc-negative grafts who underwent LT between January 2001 and December 2018. We compared recipient characteristics according to the anti-HBc status of the donor, and compared the costs of using NAs for the rest of the patient’s life and using HBIG to maintain hepatitis B surface antibody titers above 200 IU/L.

Results

The 1-, 5-, and 10-year patient survival rates were 87.7%, 73.5%, and 67.7%, respectively, in patients with anti-HBc-positive grafts, and 88.5%, 77.4%, and 70.3%, respectively, in patients with anti-HBc-negative grafts (P=0.113). Among 457 recipients with anti-HBc-positive grafts, 117 (25.6%) were non-HBV recipients. The overall incidence of DNH was 0.9%. When using HBIG under insurance coverage, the cumulative cost was lower compared with using NA continuously without insurance coverage in Korea.

Conclusions

Anti-HBc-positive grafts alone do not affect patient survival or graft survival. HBIG monoprophylaxis has good outcomes for preventing DNH, and the patient’s long-term cost burden is low in Korea because of the national insurance system in this cohort.

Safety and effectiveness of kidney transplantation using a donation after brain death donor with acute kidney injury: a retrospective cohort study

The use of kidneys from donation after brain death (DBD) donors with acute kidney injury (AKI) is a strategy to expand the donor pool. The aim of this study was to evaluate how kidney transplantation (KT) from a donor with AKI affects long-term graft survival in various situations. All patients who underwent KT from DBD donors between June 2003 and April 2016 were retrospectively reviewed. The KDIGO (Kidney Disease: Improving Global Outcomes) criteria were used to classify donor AKI. The cohort included 376 donors (no AKI group, n = 117 [31.1%]; AKI group n = 259 [68.9%]). Death-censored graft survival was similar according to the presence of AKI, AKI severity, and the AKI trend (p = 0.929, p = 0.077, and p = 0.658, respectively). Patients whose donors had AKI who received using low dose (1.5 mg/kg for three days) rabbit anti-thymocyte globulin (r-ATG) as the induction agent had significantly superior death-censored graft survival compared with patients in that group who received basiliximab (p = 0.039). AKI in DBD donors did not affect long-term death-censored graft survival. Low-dose r-ATG may be considered as an induction immunosuppression in recipients receiving kidneys with AKI because it showed better graft survival than basiliximab.

Hepatocellular Carcinoma Arising from Hepatocellular Adenoma in an Elderly Male Patient

Hepatocellular adenoma is a benign tumor of the liver occurring predominantly in young women taking oral contraceptives. The malignant transformation of hepatocellular adenoma into hepatocellular carcinoma has rarely been reported. Herein, we report the case of an elderly male patient with hepatocellular carcinoma that developed from hepatocellular adenoma. The patient's high risk for surgery and conflicting biopsy and imaging results made it difficult to determine the treatment direction. Eventually, the mass was completely removed by laparoscopic left hemi-hepatectomy without complications.

Global transcriptome analysis identifies weight regain-induced activation of adaptive immune responses in white adipose tissue of mice

Objective:

Studies have indicated that weight regain following weight loss predisposes obese individuals to metabolic disorders; however, the molecular mechanism of this potential adverse effect of weight regain is not fully understood. Here we investigated global transcriptome changes and the immune response in mouse white adipose tissue caused by weight regain.

Design:

We established a diet switch protocol to compare the effects of weight regain with those of weight gain without precedent weight loss, weight loss maintenance and chow diet. We conducted a time course analysis of global transcriptome changes in gonadal white adipose tissue (gWAT) during the weight fluctuation. Co-expression network analysis was used to identify functional modules associated with the weigh regain phenotype. Immune cell populations in gWAT were characterized by flow-cytometric immunophenotyping. Metabolic phenotypes were monitored by histological analysis of adipose tissue and liver, and blood-chemistry and body weight/composition analyses.

Results:

In total, 952 genes were differentially expressed in the gWAT in the weight regain vs the weight gain group. Upregulated genes were associated with immune response and leukocyte activation. Co-expression network analysis showed that genes involved in major histocompatibility complex I and II-mediated antigen presentation and T-cell activation function were upregulated. Consistent with the transcriptome analysis results, flow cytometry demonstrated significant increases in subsets of T cells and proinflammatory M1 macrophages in the gWAT in the weight regain as compared to the weight gain group. In addition, upregulation of adaptive immune responses was associated with high incidence of adipocyte death and upregulation of high mobility group box 1, a well-known component of damage-associated molecular patterns.

Conclusions:

Our global transcriptome analysis identified weight regain-induced activation of adaptive immune responses in mouse white adipose tissue. Results suggest that activation of adipocyte death-associated adaptive immunity in adipose tissue may contribute to unfavorable metabolic effects of weight regain following weight loss.

Oxygen-vacancy-induced orbital reconstruction of Ti ions at the interface of LaAlO3/SrTiO3 heterostructures: a resonant soft-X-ray scattering study

Resonant soft-x-ray scattering measurements have been performed to investigate interface electronic structures of (LaAlO(3)/SrTiO(3)) superlattices. Resonant scattering intensities at superlattice reflections show clear evidence of degeneracy lifting in t(2g) states of interface Ti ions. Polarization dependence of intensities indicates the energy of d(xy) states is lower by ~1 eV than two other t(2g) states. The energy splitting is insensitive to epitaxial strain. The orbital reconstruction is induced by oxygen vacancies and confined to the interface within two unit cells, indicating charge compensation at the polar interfaces.

Allelic variation of the Waxy gene in foxtail millet [Setaria italica (L.) P. Beauv.] by single nucleotide polymorphisms

The Waxy (Wx) gene product controls the formation of a straight chain polymer of amylose in the starch pathway. Dominance/recessiveness of the Wx allele is associated with amylose content, leading to non-waxy/waxy phenotypes. For a total of 113 foxtail millet accessions, agronomic traits and the molecular differences of the Wx gene were surveyed to evaluate genetic diversities. Molecular types were associated with phenotypes determined by four specific primer sets (non-waxy, Type I; low amylose, Type VI; waxy, Type IV or V). Additionally, the insertion of transposable element in waxy was confirmed by ex1/TSI2R, TSI2F/ex2, ex2int2/TSI7R and TSI7F/ex4r. Seventeen single nucleotide polymorphims (SNPs) were observed from non-coding regions, while three SNPs from coding regions were non-synonymous. Interestingly, the phenotype of No. 88 was still non-waxy, although seven nucleotides (AATTGGT) insertion at 2,993 bp led to 78 amino acids shorter. The rapid decline of r (2) in the sequenced region (exon 1-intron 1-exon 2) suggested a low level of linkage disequilibrium and limited haplotype structure. K (s) values and estimation of evolutionary events indicate early divergence of S. italica among cereal crops. This study suggested the Wx gene was one of the targets in the selection process during domestication.

Fabrication of fluorine-doped diamond-like carbon stamps for UV nanoimprint lithography

Two fluorine-doped diamond-like carbon (F-DLC) stamps with sub-100 nm line patterns were fabricated using a direct etching method. These were applied successfully to ultraviolet (UV) nanoimprint lithography without requiring an anti-adhesion layer coating. Tests were performed to determine the optimum fluorine concentration for the F-DLC stamps. The ideal stamp material consisted of 25 at.% F-DLC with a contact angle of 85°, UV transmittance of 16.4-26.8%, and hardness of 4.5 GPa. The O(2) plasma etch rate of the DLC was increased considerably by the fluorine doping, making it comparable to the etch rate of polymethyl methacrylate (PMMA). Thus, only PMMA was used as the etch mask in the fabrication of the stamps.

The three-dimensional microstructure of the trabecular bone in the mandible

This study investigated the three dimensional (3D) trabecular microstructure of the alveolar and basal bone in the mandible using micro-CT and compared the morphometric values of the different sites. Ten specimens were prepared and scanned using a micro-CT system. Both the alveolar and basal trabecular bone of the premolar region in the mandible were measured for the structural analysis. Cross-sectional 1024x1024 pixel images were created. From the two-dimensional (2D) images produced, 3D structural images were reconstructed. After scanning the specimen, the volumes of interest (VOI) of the alveolar and basal bone regions were selected from the 3D reconstruction images, and the structural parameters such as bone volume fraction, bone surface density, trabecular thickness, trabecular separation, trabecular number and structural model index were analyzed. The trabecular structure showed a marked variation within the sites of the specimen, especially in the basal trabecular bone inferior to the mandibular canal. In both the alveolar and basal bone regions, a mixture of both plate-like and rod-like structures was observed. The alveolar region showed a more compact, plate-type trabecular structure than the basal regions. In parametric comparison with the basal bone, the alveolar bone generally had a higher bone volume fraction, bone trabecular thickness and trabecular number, and lower bone surface density, trabecular separation and structural model index. The alveolar bone consisted of a compact bone structure with a large amount of thick plate-type trabecular bone, which was effectively resistant to the masticatory forces. As the measurements were made closer to the basal bone, a loose structure was observed with lower bone volume and fewer, thin, rod-like trabeculae.

Inflammatory orbital pseudotumor with infratemporal fossa extension mimicking temporomandibular joint dysfunction

Inflammatory orbital pseudotumor is a benign space-occupying lesion of unknown origin that involves all or part of the fatty tissue within the orbit. Occasionally the disease may extend into the middle cranial, the pterygopalatine, and the infratemporal fossa through the various foramina of the orbit, although extension into the infratemporal fossa is very rare. We present a case which extends into the infratemporal fossa through the inferior orbital fissure, resulting in presenting symptoms mimicking temporomandibular joint dysfunction.

Knowledge and attitudes of Korean parents towards their son's circumcision: a nationwide questionnaire study

OBJECTIVE

To evaluate knowledge about the foreskin and circumcision, and to understand the attitudes of parents to circumcision in Korea, where circumcision in childhood is widely practised with no particular religious or medical background.

SUBJECTS AND METHODS

A nationwide study involving questionnaires was conducted on 5500 parents with at least one son attending elementary school. Responses were obtained from one of the parents.

RESULTS

The response rate was 76.1% (4183); circumcision was most common in boys when aged 11 years, followed by neonatal circumcision. Of the parents, 91.3% believed that circumcision is necessary, while 2.1% believed it to be unnecessary. The principal reasons given for circumcision were 'to improve penile hygiene' (82.4%), followed by 'to improve future sexual potency' (7.5%). Among those who did not believe circumcision to be necessary, the most common reason was the expectation of spontaneous retraction of the prepuce with age (55.1%). Most (88.4%) of the parents believed that smegma is not a clean material, and is infected by microorganisms. Most parents (80.6%) thought that circumcision would prevent genital tract infection of the future spouse. Peer pressure was one of the most influential factors in deciding upon circumcision; 41.9% of the parents were anxious that their child might be ridiculed by his peer group unless he was circumcised, while 27.4% of the parents believed that their child might be ridiculed if he was circumcised. Mothers were more positive about circumcision than fathers (P < 0.05). Parents with a higher education and higher socio-economic status were also more positive about circumcision (P < 0.05). Mothers were prone to emphasize improved sexual potency (P < 0.05). There was no significant difference in response between urban and rural areas.

CONCLUSION

This study indicates that common beliefs held by parents about the prepuce or circumcision differ significantly from current medical knowledge, and these beliefs have a major influence on the practice of circumcision in Korea. More clinical research on the natural history of the foreskin is needed, and it is critical that both children and parents are informed about the potential benefits and disadvantages of circumcision.

Cloning and characterization of a type II integral transmembrane protein gene, Itm2c, that is highly expressed in the mouse brain

An Itm2C cDNA encoding a member of the mouse type II integral transmembrane protein (Itm2) was cloned from a mouse 13.5 days' post-coitum (dpc) embryonic head cDNA library. The nucleotide sequence and protein prediction analyses indicate that the membrane topology of the mouse Itm2c is a type II integral transmembrane protein with the N-terminus being intracellular and C-terminus, which is considered as either an extracellular or a luminal organelle domain. The predicted protein consists of 269 amino acids with a calculated Mr of 30,482 and a theoretical pI of 8.83. A putative N-glycosylation site was identified at amino acid 171, Asn. The single N-glycosylation site is conserved in the three members of the family in both mice and humans. The amino acid sequence of Itm2C is 41 and 49% identical to those of mouse Itm2A and Itm2B, respectively. A single approximately 2.1 kb transcript was detected with different levels in all of the tissues examined by Northern blot analysis. The Itm2c was highly expressed in both adult and postimplantation embryonic brains, although weak or moderate signals were also detected in other adult tissues. Among the tissues examined, RT-PCR analyses in various adult tissue shows that the Itm2c expression is highest in the adult brain. The results from this study suggest that the cloned Itm2c is a member of the Itm2 family that is specifically expressed in adult brains, unlike other members.

Isolation of neuronal precursors from differentiating P19 embryonal carcinoma cells by neuronal T alpha 1-promoter-driven GFP

The induction of pluripotent P19 embryonal carcinoma (EC) cells with retinoic acid results in their differentiation into cells that resemble neurons, glia, and fibroblasts. To isolate and enrich the developing neurons from heterogeneously differentiating P19 EC cells, we used a recently introduced protocol combining the expression of green fluorescent protein (GFP) driven by a tissue-specific promoter and fluorescence-activated cell sorting. Cells were transfected with the gene for GFP, which is under the control of the neuronal T alpha 1 tubulin promoter. After four days of retinoic acid treatment, GFP was specifically detected in cells undergoing neuronal differentiation. Sorting of fluorescent differentiating P19 EC transfectants yielded populations highly enriched in neuronal precursors and neurons. Immunoreactivity for nestin and neurofilament was observed in 80 and 25% of the sorted cell population, respectively. These results demonstrate that differentiated neuronal precursor cells can be efficiently isolated from differentiating pluripotent embryonic cells in vitro, suggesting that this method can reproducibly provide homogeneous materials for further studies on neurogenesis.

Dendritic cell-tumor coculturing vaccine can induce antitumor immunity through both NK and CTL interaction

Immunization of dendritic cells (DC) pulsed with tumor antigen can activate tumor-specific cytotoxic T lymphocytes (CTL) that are responsible for protection and regression. We show here that immunization with bone marrow-derived DC cocultured with tumor cells can induce a protective immunity against challenges to viable tumor cells. In this study, we further investigated the mechanism by which the antitumor activity was induced. Immunization of mice with DC cocultured with murine colon carcinoma. CT-26 cells, augmented CTL activity against the tumor cells. Concomitantly, an increase in natural killer (NK) cell activity was also detected in the same mice. When DC were fixed with paraformaldehyde prior to coculturing with tumor cells, most of the CTL and NK cell activity diminished, indicating that DC are involved in the process of presenting the tumor antigen(s) to CTL. NK cell depletion in vivo produced markedly low tumor-specific CTL activity responsible for tumor prevention. In addition, RT-PCR analysis confirmed the high expression of INF-gamma mRNA in splenocytes after vaccination with DC cocultured with tumors, but low expression in splenocytes from NK-depleted mice. Most importantly, the tumor protective effect rendered to DC by the coculturing with CT-26 cells was not observed in NK-depleted mice, which suggests that DC can induce an antitumor immune response by enhancing NK cell-dependent CTL activation. Collectively, our results indicate that NK cells are required during the priming of cytotoxic T-cell response by DC-based tumor vaccine and seem to delineate a mechanism by which DC vaccine can provide the desired immunity.

Apoptosis-linked gene 2 binds to the death domain of Fas and dissociates from Fas during Fas-mediated apoptosis in Jurkat cells

Apoptosis-linked gene 2 (ALG-2) is a member of the family of Ca(2+)-binding proteins with penta-EF-hand and is essential for the execution of apoptosis by various signals including Fas activation. We studied the regulation of ALG-2 during Fas-mediated apoptosis in Jurkat cells. The 22-kDa ALG-2 protein is cleaved and becomes a 19-kDa protein after Fas activation. The appearance of 19-kDa ALG-2 protein increases for 4 h after treatment with 200 ng/ml of anti-Fas Ab treatment and gradually degrades afterward. Confocal microscopic analysis showed that ALG-2 translocated from the plasma membrane to the cytosol during Fas-mediated apoptosis. Therefore, we examined if ALG-2 interacts with Fas. The protein-protein interaction of ALG-2 with Fas was demonstrated using yeast two-hybrid assays as well as in vitro GST pull-down assay. Endogenous ALG-2 was immunoprecipitated with anti-Fas Ab in Jurkat cells without Fas activation. However, the endogenous ALG-2 was no longer immunoprecipitated with anti-Fas Ab 2 h after anti-Fas Ab treatment. This study, for the first time, presents a direct molecular connection of ALG-2 to apoptosis by its direct interaction with Fas, and enlists ALG-2 as a new member of posttranslationally modified proteins during Fas-mediated apoptotic process.

Multiple cemento-ossifying fibroma: report of an 18-year follow-up

Multiple cemento-ossifying fibroma is a very rare jaw lesion. A unique case is reported involving a 43-year-old Korean woman with rapidly growing, multiple cemento-ossifying fibromas in all four quadrants over an 18-year period which resulted in severe facial deformity and orbital compression.

alpha(6) Integrin is the main receptor of human papillomavirus type 16 VLP

The present study was performed to determine the specific receptor of type HPV-16 using recombinant human papillomavirus-like particle (HPV-16 L1-VLP). The expression levels of alpha(6), beta(1), and beta(4) integrins were determined and compared with the amount of HPV-VLP binding in ten cell lines by flow cytometry. Our results show that the amount of VLP binding and the expression level of alpha(6) integrin are correlated, which was confirmed by an inhibition experiment using antibodies and by immunocytochemistry. Both the expression level of alpha(6) integrin and the amount of HPV-VLP binding were high in cervical cancer cell lines, as the type HPV-16 is the main cause of cervical cancer. The degree of binding of HPV-VLP matched the alpha(6) integrin expression level in cell lines but was not correlated with beta(1) and beta(4) levels, which suggests that alpha(6) integrin is the main receptor of HPV type 16.

Inhibition of glucocorticoid-mediated, caspase-independent dendritic cell death by CD40 activation

Glucocorticoids (GC) are potent anti-inflammatory and immunosuppressive agents that act on a variety of immune cells, including T cells, monocytes/macrophages, osteoclasts, and dendritic cells (DC). However, the mechanism(s) by which GC exert anti-inflammatory effects is still largely unknown. It is already well known that GC treatment inhibits DC maturation and interleukin (IL)-12 production by DC. In this study, we investigated the apoptosis induction of DC by a synthetic GC, dexamethasone (Dex). The stimulation with Dex resulted in DC apoptosis in a dose- and time-dependent manner as it was measured by determining annexin V-positive cells and mitochondrial potential. In contrast, monocytes that are precursor cells of DC are resistant to Dex-mediated apoptosis. The Dex-induced apoptosis of DC was independent of caspase activation because it was not inhibited by the broad caspase inhibitor, Z-VAD-fmk. It is interesting that agonistic CD40 antibody completely inhibited Dex-induced cell death, whereas other inflammatory stimuli did not show the same effect, suggesting that CD40 signaling may selectively modulate GC-mediated DC apoptosis. Taken together, our findings revealed an important role of GC and CD40 signaling in the regulation of immune responses in which DC play a key role in the inflammatory process of various immunomediated diseases.

Computer-assisted thoracic pedicle screw placement: an in vitro feasibility study

STUDY DESIGN

In this cadaveric study, a computer-assisted image guidance system was tested for accuracy of thoracic pedicle screw placement.

OBJECTIVES

Evaluate the system's accuracy for thoracic pedicle screw placement in vitro.

SUMMARY OF BACKGROUND DATA

The effective use and reliability of pedicle screw instrumentation in providing short-segment stabilization and correction of deformity is well known in the lumbar spine. Pedicle screw placement in the thoracic spine is difficult because of the small dimensions of the thoracic pedicles and risk to the adjacent spinal cord and neurovascular structures. Investigators have shown the improved accuracy of computer-assisted lumbar pedicle screw placement; but the accuracy of computer-assisted thoracic pedicle screw placement, which is becoming more widely used, has not been shown.

METHODS

In five human cadavers, 120 thoracic pedicle screws were placed with computer-assisted image guidance. The largest clinically feasible screw was used based on the cross-sectional dimensions of each pedicle. The accuracy was assessed by postoperative computed tomography and visual inspection.

RESULTS

The overall pedicle cortex violation was 23 of 120 pedicles (19.2%). Nine violations (7.5%) were graded as major and 14 (11.7%) as minor. A marked and progressive learning curve was evident with the perforation rates that decreased from 37.5% in the first cadaver to 4.2% in the last two cadavers.

CONCLUSIONS

Accurate thoracic pedicle screw placement is feasible with computer-assisted surgery. However, as with any other new surgical technology, the learning curve must be recognized and incorporated into the necessary fundamental knowledge and experience for these procedures.

Image-guided thoracic pedicle screw placement: a technical study in cadavers and preliminary clinical experience

OBJECT

Thoracic pedicle screw fixation is effective and reliable in providing short-segment stabilization. Although the procedure is becoming more widely used, accurate insertion of the screws is difficult due to the small dimensions of thoracic pedicles, and the associated risk is high due to the proximity of the spinal cord. In previous studies authors have shown the accuracy of image-guided lumbar pedicle screw placement, but there have been no reported investigations into the accuracy of image-guided thoracic pedicle screw placement. The authors report their experience with such an investigation.

METHODS

To evaluate the accuracy of image-guided thoracic pedicle screw placement in vitro and in vivo, thoracic pedicle screws were placed with an image-guidance system in five human cadavers and 10 patients. In cadavers, the accuracy of screw placement was assessed by postoperative computerized tomography and visual inspection and in patients by postoperative imaging studies. Of the 120 pedicle screws placed in five cadavers pedicle violation occurred in 23 cases (19.2%); there was one pedicle violation (4.2%) in each of the last two cadavers. Of the 45 pedicle screws placed in 10 patients, pedicle violations occurred in three (6.7%).

CONCLUSIONS

In comparison with historical controls, the accuracy of thoracic pedicle screw placement is improved with the use of an image-guidance system. It allows the surgeon to visualize the thoracic pedicle and the surrounding structures that are normally out of the surgical field of view. The surgeon, however, must be aware of the limitations of an image-guidance system and have a sound basic knowledge of spinal anatomy to avoid causing serious complications.

Mesenchymal hamartomas of the chest wall in infancy: radiologic and pathologic correlation

Mesenchymal hamartoma of the chest wall is a rare tumor with about 53 reported cases in the English literature. We reviewed six chest wall mesenchymal hamartomas in four patients, including two cases with multiple lesions, with specific focus on the radiologic and pathologic correlation. All cases occurred in neonates or infants with ages ranging from seven hours to seven months. They were diagnosed with plain chest radiographs (n=6), ultrasonography (n=2), chest CT scan (n=6), whole body bone scan (n=2) and MRI (n=3). All cases except a small one without cystic change showed the typical features of mesenchymal hamartoma radiographically and pathologically. Radiologically they were well-circumscribed masses with solid and cystic components with multiple fluid-fluid levels in association with single or multiple rib destruction or change. The CT scan showed the typical findings of chest wall hamartoma, and the MR showed heterogeneous signal intensities of the mass on T1- and T2-weighted images. The MR also revealed more concisely a secondary aneurysmal bone cyst formation with multiple fluid-fluid levels on the T2-weighted image. Microscopically, they showed alternating areas of cartilaginous islands and primitive appearing mesenchymal proliferation, which corresponded well with the solid component on the radiologic findings. The areas of bone formation and blood-filled cystic spaces matched the calcified or ossified densities and the cystic components, respectively. A small case without cystic change showed peculiar radiological and pathological findings resembling an osteochondroma. In conclusion, mesenchymal hamartoma of the chest wall in infancy is quite rare and sometimes can be misdiagnosed as malignancy due to the bone-destroying radiographic appearance and the highly cellular and mitotically active microscopic features, unless the radiologists and pathologists are aware of the characteristic clinical, radiological, and pathological findings. Imaging studies can usually make a correct diagnosis with good correlation to the pathologic findings.

Imaging-guided costotransversectomy for thoracic disc herniation

The surgical management of thoracic disc disease remains challenging. Outcomes after laminectomy had been poor, and modern posterolateral, lateral, and anterior approaches have evolved to replace this older procedure. Each has its own set of complications, and all are hampered, to varying degrees, by the limited visualization of the ventral disc space and spinal cord during decompression. The authors present their early experience with computer-assisted image guidance as an adjunctive tool for preoperative planning and navigation in the treatment of thoracic disc disease. Five consecutive patients underwent image-guided costotransversectomies between January 1999 and April 2000. The levels of herniation were T8–9 in three and T7–8 and T5–6, respectively, in the other two. There were four centrolateral herniations and one midline herniation. Three discs were soft and two hard. Two patients had previously undergone failed disc excisions. All patients had axial pain and myeloradiculopathies preoperatively. Three were unable to walk.

Four patients enjoyed good or excellent outcomes, with return of ambulation. One patient experienced only mild improvement in her severe paraparesis. Image-guidance was invaluable in planning the corpectomy and aiding visualization in situations in which the dura or disc were obscured; its use allowed successful surgical excisions in the most challenging circumstances.

Review of spinal pseudomeningoceles and cerebrospinal fluid fistulas

Spinal pseudomeningoceles and cerebrospinal fluid (CSF) fistulas are uncommon extradural collections of CSF that may result from inadvertent tears in the dural-arachnoid layer, traumatic injury, or may be congenital in origin. Most pseudomeningoceles are iatrogenic and occur in the posterior lumbar region following surgery. The true incidence of iatrogenic pseudomeningoceles following laminectomy or discectomy is unknown; however, the authors of several published reports suggest that the incidence of lumbar pseudomeningoceles following laminectomy or discectomy is between 0.07% and 2%. Pseudomeningoceles are often asymptomatic, but patients may present with recurrence of low-back pain, radiculopathy, subcutaneous swelling, or with symptoms of intracranial hypotension. Very rarely, they present with delayed myelopathy. Although magnetic resonance imaging is the neurodiagnostic study of choice, computerized tomography myelography and radionuclide myelographic study may be helpful diagnostic tools in some cases. Analysis of suspect fluid for Beta2 transferrin may be a useful adjunctive study. Treatment options include close observation for spontaneous resolution, conservative measures such as bed rest and application of an epidural blood patch, lumbar subarachnoid drainage, and definitive surgical repair.

New software applications for interchangeable instrumentation in spinal stereotaxis

Computer image-guided surgery has been widely accepted because it allows the surgeon to track an instrument through unvisualized critical structures of a patient in real-time, thus minimizing the risk of injury. Current spinal and cranial image-guided surgery is, however, limited by the lack of surgical instruments and software applications that would allow rapid interchange of useful instruments to perform the procedures. Most image-guided systems utilize a single standard probe or a few pre-defined instruments that are not necessarily useful for performing the actual surgical procedure. Present image-guided technology for screw placement in spinal surgery utilizes the standard probe only to confirm the entry point location and view the planned trajectory of the screw. The surgeon then resumes the procedure using standard surgical instruments to drill, tap and place screws without the benefit of image guidance. Our clinical laboratory experience with spinal image-guided surgery indicates that there is potential for error between each of these procedural steps of screw placement. Despite accurately locating an entry point, any deviation in the trajectory during drilling of a pilot hole, tapping or screw placement may result in significant errors in screw placement and potential neurovascular injury. We have developed custom software applications and universal hardware adaptation devices for spinal image-guided surgery that allow the use of standard instruments for intraoperative guidance. Utilizing universal dynamic registration hardware and software, standard surgical instruments are adapted for real-time image guided surgery. An array of light emitting diodes can be attached to essentially any rigid instrument with a definable tip and then calibrated to the system for intraoperative use. Laboratory tests using a cadaveric model indicate a difference in accuracy of less than 1.0 mm between the standard probe and a dynamically registered custom instrument and an absolute mean error of less than 2.0 mm for the image-guided system which is clinically insignificant in most cases. This technology is a significant step forward as it allows the surgeon to use a full array of instruments with image guidance and will ultimately make spinal and intracranial surgery safer and more accurate.

Influence of Anodic Surface Treatment of Activated Carbon on Adsorption and Ion Exchange Properties

The effect of anodic surface treatment of activated carbon on adsorption and ion exchange characteristics was investigated in the condition of 35 wt% NaOH electrolyte for 60 s. The acid and base values were determined by a titration technique, and surface and pore structures were studied in terms of BET volumetric measurement with N(2) adsorption. The ion exchange capacity of the anodized activated carbons was characterized by a dry weight capacity technique. It was observed that an increase in current intensity leads to an increase in the surface functional groups of activated carbons, resulting in increasing pH, acid-base values, and anion-cation exchange capacities, without significant change of surface and pore structures (i.e., specific surface area, total pore volume, micropore volume, and average pore diameter). Also, anodically treated activated carbons are more effectively evaluated on the base value or cation exchange capacity than on the opposite properties in this electrolytic system. Copyright 1999 Academic Press.

Idiopathic bronchiolitis obliterans with organizing pneumonia presenting with spontaneous hydropneumothorax and solitary pulmonary nodule

The first case of idiopathic bronchiolitis obliterans with organizing pneumonia (BOOP) presenting as solitary pulmonary nodule with spontaneous hydropneumothorax is reported in a 54-year-old man. A wedge resection of the right lower lobe was performed to show typical histological features of BOOP. This case report demonstrates that BOOP has a very diverse clinical manifestation and stresses the need to include solitary pulmonary nodule with hydropneumothorax in the spectrum of BOOP.

Protective antitumor activity through dendritic cell immunization is mediated by NK cell as well as CTL activation

Dendritic cells (DCs) are potent professional antigen-presenting cells (APC) capable of inducing the primary T cell response to antigen. Although tumor cells express target antigens, they are incapable of stimulating a tumor-specific immune response due to a defect in the costimulatory signal that is required for optimal activation of T cells. In this work, we describe a new approach using tumor-DC coculture to improve the antigen presenting capacity of tumor cells, which does not require a source of tumor-associated antigen. Immunization of a weakly immunogenic and progressive tumor cocultured with bone marrow-derived DCs generated an effective tumor vaccine. Immunization with the cocultured DCs was able to induce complete protective immunity against tumor challenges and was effective for the induction of tumor-specific CTL (cytotoxic T lymphocyte) activity. Furthermore, high NK cell activity was observed in mice in which tumors were rejected. In addition, immunization with tumor-pulsed DCs induced delayed tumor growth, but not tumor eradication in tumor-bearing mice. Our results demonstrate that coculture of DCs with tumors generated antitumor immunity due to the NK cell activation as well as tumor-specific T cell. This approach would be useful for designing tumor vaccines using DCs when the information about tumor antigens is limited.

Enhanced antigen-presenting activity and tumour necrosis factor-alpha-independent activation of dendritic cells following treatment with Mycobacterium bovis bacillus Calmette-Guérin

Dendritic cells (DCs) are most potent among the antigen-presenting cells and are believed to be crucial for the initiation of a primary T-cell response to foreign antigens. Mycobacterial infection within macrophages is controlled by cell-mediated immunity. To elucidate the stimulation of immune response by Mycobacterium bovis bacillus Calmette-Guérin (BCG), we purified DCs from precursor cells in human peripheral blood mononuclear cells (PBMC) by culturing them with granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4) and characterized their surface antigen expression. The interaction of cultured DCs with BCG resulted in increased surface expression of several DC-related marker antigens. BCG also induced reduction of endocytosis, enhancement of CD83 expression as well as B7 costimulatory molecules and IL-12 production, suggesting that BCG treatment directly induces DCs to mature. BCG-treated DCs were much more potent antigen-presenting cells in allogeneic immune response than untreated DCs. Moreover, while the neutralization of tumour necrosis factor-alpha (TNF-alpha) significantly blocked the DC maturation induced by lipopolysaccharide (LPS), it could not inhibit the induction of DC maturation by the BCG treatment, indicating that TNF-alpha production plays a minor role in the BCG-induced DC maturation. However, the neutralization of TNF-alpha resulted in decreased IL-12 production by activated DCs. These results suggest that infection with BCG might evoke direct activation and maturation of DC and the general immune stimulant effect of BCG might be related with the activation of DCs.

Microdeletions within the azoospermia factor subregions of the Y chromosome in patients with idiopathic azoospermia

OBJECTIVE

To examine the patterns of submicroscopic DNA deletions in the AZF (AZoospermia Factor) subregions of the Y chromosome in patients with idiopathic azoospermia.

DESIGN

Controlled clinical study.

SETTING

University-based infertility clinic.

PATIENT(S)

Infertile men (n = 40) with nonobstructive, idiopathic azoospermia. The control group consisted of proven fathers (n = 14) and healthy women (n = 4).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Semen analysis; polymerase chain reaction amplification of the 37 loci spanning the AZFa, AZFb, and AZFc subregions of the Y chromosome; serum FSH, LH, and testosterone levels; and testicular histologic analysis.

RESULT(S)

Testicular histologic analysis of the subjects revealed Sertoli cell-only syndrome (n = 36) and spermatogenic arrest (n = 4). Microdeletions of the Y chromosome were found in eight (20%) of the patients with azoospermia. All eight affected patients had interstitial microdeletions within the AZFc subregion. Patients with Sertoli cell-only syndrome had additional microdeletions in regions distal to DAZ (Deleted in Azoospermia), although DAZ deletion was observed in seven of the eight affected patients. In five patients, microdeletions were found in the AZFb region containing RBM (RNA Binding Motif).

CONCLUSION(S)

Our results add to the evidence supporting the current suggestion that there is a cause-and-effect relation between Yq11 microdeletions in the AZF region and azoospermia.

Adsorption Behaviors of CO2 and NH3 on Chemically Surface-Treated Activated Carbons

The adsorption characteristics of activated carbon treated with 30 wt% HCl and 30 wt% NaOH were investigated. The acid and base values were determined by Boehm's method and the surface structures were studied by the BET method with N2 adsorption and iodine adsorption capacity. Also the adsorption properties of the activated carbons treated with acid and base chemical solutions were investigated with CO2 and NH3 adsorptions. Different adsorption behaviors of CO2 and NH3 on the modified activated carbons were observed, even though the physical surfaces of the activated carbons (i.e., specific surface area, pore size, and pore volume) were not significantly changed. Copyright 1999 Academic Press.

Effects of androgens on the expression of nitric oxide synthase mRNAs in rat corpus cavernosum

OBJECTIVE

To examine the effects of androgens on erectile response and the expression of nitric oxide synthase (NOS) isoform mRNAs in the penile corpus cavernosum of castrated rats.

MATERIALS AND METHODS

The study comprised 50 adult male Sprague-Dawley rats in five groups: sham controls; castrated; castrated and receiving testosterone; castrated and receiving dihydrotestosterone (DHT); castrated and receiving testosterone and 5alpha-reductase inhibitor (finasteride). Androgen replacements were administered via implants of silicone tubing. After 7 days, some animals underwent electrical stimulation of the cavernosal nerves and the remainder were used for further analysis. NOS activity was measured in the soluble fraction of the corpus cavernosum, using the Griess reaction. Total RNA was isolated and nNOS and eNOS mRNA expression examined using semiquantitative reverse-transcriptase polymerase chain reaction.

RESULTS

Castration caused a marked decrease in erectile response and the ratio of maximal intracavernosal pressure (ICPmax) to systemic blood pressure (SBP), although both testosterone and DHT effectively restored the response to normal. NOS activity and the amount of nNOS mRNA were reduced in castrated rats but restored by androgen replacement. Although there was no significant difference in NOS activity between the androgens, nNOS mRNA expression was higher in rats treated with DHT. There were no effects of androgen in rats treated with finasteride, as the ICPmax/SBP ratio, NOS activity and amount of nNOS mRNA decreased. eNOS mRNA expression was independent of androgen.

CONCLUSIONS

Androgens enhance nNOS gene expression in the penile corpus cavernosum of rats, suggesting that they play an important role in maintaining NOS activity. Of the two androgens, DHT was more potent.