Contour prognostic model for predicting survival after resection of colorectal liver metastases: development and multicentre validation study using largest diameter and number of metastases with RAS mutation status

BACKGROUND

Most current models for predicting survival after resection of colorectal liver metastasis include largest diameter and number of colorectal liver metastases as dichotomous variables, resulting in underestimation of the extent of risk variation and substantial loss of statistical power. The aim of this study was to develop and validate a new prognostic model for patients undergoing liver resection including largest diameter and number of colorectal liver metastases as continuous variables.

METHODS

A prognostic model was developed using data from patients who underwent liver resection for colorectal liver metastases at MD Anderson Cancer Center and had RAS mutational data. A Cox proportional hazards model analysis was used to develop a model based on largest colorectal liver metastasis diameter and number of metastases as continuous variables. The model results were shown using contour plots, and validated externally in an international multi-institutional cohort.

RESULTS

A total of 810 patients met the inclusion criteria. Largest colorectal liver metastasis diameter (hazard ratio (HR) 1.11, 95 per cent confidence interval 1.06 to 1.16; P < 0.001), number of colorectal liver metastases (HR 1.06, 1.03 to 1.09; P < 0.001), and RAS mutation status (HR 1.76, 1.42 to 2.18; P < 0.001) were significantly associated with overall survival, together with age, primary lymph node metastasis, and prehepatectomy chemotherapy. The model performed well in the external validation cohort, with predicted overall survival values almost lying within 10 per cent of observed values. Wild-type RAS was associated with better overall survival than RAS mutation even when liver resection was performed for larger and/or multiple colorectal liver metastases.

CONCLUSION

The contour prognostic model, based on diameter and number of lesions considered as continuous variables along with RAS mutation, predicts overall survival after resection of colorectal liver metastasis.

Performance of a modified three-level classification in stratifying open liver resection procedures in terms of complexity and postoperative morbidity

BACKGROUND

Traditional classifications for open liver resection are not always associated with surgical complexity and postoperative morbidity. The aim of this study was to test whether a three-level classification for stratifying surgical complexity based on surgical and postoperative outcomes, originally devised for laparoscopic liver resection, is superior to classifications based on a previously reported survey for stratifying surgical complexity of open liver resections, minor/major nomenclature or number of resected segments.

METHODS

Patients undergoing a first open liver resection without simultaneous procedures at MD Anderson Cancer Center (Houston cohort) or the University of Tokyo (Tokyo cohort) were studied. Surgical and postoperative outcomes were compared among three grades: I (wedge resection for anterolateral or posterosuperior segment and left lateral sectionectomy); II (anterolateral segmentectomy and left hepatectomy); III (posterosuperior segmentectomy, right posterior sectionectomy, right hepatectomy, central hepatectomy and extended left/right hepatectomy).

RESULTS

In both the Houston (1878 patients) and Tokyo (1202) cohorts, duration of operation, estimated blood loss and comprehensive complication index score differed between the three grades (all P < 0·050) and increased in stepwise fashion from grades I to III (all P < 0·001). Left hepatectomy was associated with better surgical and postoperative outcomes than right hepatectomy, extended right hepatectomy and right posterior sectionectomy, although these four procedures were categorized as being of medium complexity in the survey-based classification. Surgical outcomes of minor open liver resections also differed between the three grades (all P < 0·050). For duration of operation and blood loss, the area under the curve was higher for the three-level classification than for the minor/major or segment-based classification.

CONCLUSION

The three-level classification may be useful in studies analysing open liver resection at Western and Eastern centres.

[Prognostic value of TIMI and GRACE risk scores for in-hospital mortality in Chinese patients with non-ST-segment elevation myocardial infarction]

Objective: To evaluate the prognostic value of the thrombolysis in myocardial infarction (TIMI) and global registry of acute coronary events (GRACE) risk scores for in-hospital mortality in Chinese non-ST-segment elevation myocardial infarction (NSTEMI) patients. Methods: Data of present study derived from the prospective, multi-center registry trial of Chinese AMI (CAMI). Among 31 provinces, municipalities or autonomous districts in China, at least one tertiary and secondary hospital was selected. From January 2013 to September 2014, 5 896 consecutive non-ST-segment elevation myocardial infarction patients who were admitted to 107 hospitals within 7 days of symptom onset were enrolled. For each patient, TIMI and GRACE risk scores were calculated using specific variables collected at admission. Their prognostic value was evaluated by the endpoint of in-hospital mortality. Results: Among 5 896 NSTEMI patients (age was (65.4±12.1) years old), 68.2% (n=4 020) were males. The in-hospital mortality was 6.0% (n=353) and the median length of hospital stay was 10.0 (7.0, 13.0) days. The incidence of pre-hospital cardiac arrest was 3.6% (n=213) among 5 896 NSTEMI patients. Six hundreds and forty five patients (10.9%) received primary percutaneous coronary intervention, and 6 patients underwent emergent coronary artery bypass grafting surgery (0.1%), and the median time of reperfusion was 529.5 (256.0, 1 065.0) minutes. The prescription percentage of statins, β-blocker, angiotensin converting enzyme inhibitors or angiotensin Ⅱ receptor blockers, and aldosterone antagonists were 94.8% (n=5 587), 71.7% (n=4 228), 65.5% (n=3 864) and 26.0% (n=1 533) respectively. The area under the curve of GRACE risk score for in-hospital mortality (0.7930 (95%CI 0.767-0.818)) was better than that of TIMI risk score (0.5588 (95%CI 0.532-0.586), P<0.001). Conclusion: GRACE risk score demonstrates better predictive accuracy than TIMI risk score for in-hospital mortality in NSTEMI patients in this patient cohort.

Prognostic impact of perihepatic lymph node metastases in patients with resectable colorectal liver metastases

BACKGROUND

Although perihepatic lymph node metastases (PLNMs) are known to be a poor prognosticator for patients with colorectal liver metastases (CRLMs), optimal management remains unclear. This study aimed to determine the risk factors for PLNMs, and the survival impact of their number and location in patients with resectable CRLMs.

METHODS

Data on patients with CRLM who underwent hepatectomy during 2003-2014 were analysed retrospectively. Recurrence-free (RFS) and overall (OS) survival were calculated according to presence, number and location of PLNMs. Risk factors for PLNM were evaluated by logistic regression analysis.

RESULTS

Of 1485 patients, 174 underwent lymphadenectomy, and 54 (31·0 per cent) had PLNM. Ten patients (5·7 per cent) who had lymphadenectomy and 176 (13·4 per cent) who did not underwent repeat hepatectomy. Survival of patients with PLNM was significantly poorer than that of patients without (RFS: 5·3 versus 13·8 months, P < 0·001; OS: 20·5 versus 71·3 months; P < 0·001). Median OS was significantly better in patients with para-aortic versus hepatoduodenal ligament PLNMs (58·2 versus 15·5 months; P = 0·011). Patients with three or more PLNMs had significantly worse median OS than those with one or two (16·3 versus 25·4 months; P = 0·039). The presence of primary tumour lymph node metastases (odds ratio 2·35; P = 0·037) and intrahepatic recurrence requiring repeat hepatectomy (odds ratio 5·61; P = 0·012) were significant risk factors for PLNM on multivariable analysis.

CONCLUSION

Patients undergoing repeat hepatectomy and those with primary tumour lymph node metastases are at significant risk of PLNM. Although PLNM is a poor prognostic factor independent of perihepatic lymph node station, patients with one or two PLNMs have a more favourable outcome than those with more PLNMs.

Biomarkers in colorectal liver metastases

BACKGROUND

Despite a 5-year overall survival rate of 58 per cent after liver resection for colorectal liver metastases (CLMs), more than half of patients develop recurrence, highlighting the need for accurate risk stratification and prognostication. Traditional prognostic factors have been superseded by newer outcome predictors, including those defined by the molecular origin of the primary tumour.

METHODS

This review synthesized findings in the literature using the PubMed database of articles in the English language published between 1998 and 2017 on prognostic and predictive biomarkers in patients undergoing resection of CLMs.

RESULTS

Responses to preoperative chemotherapy define prognosis in patients undergoing CLM resection. There are differences by embryological origin too. Somatic mutations in the proto-oncogenes KRAS and NRAS are associated with positive surgical margins and tumour regrowth after ablation. Other mutations (such as BRAF) and co-occurring mutations in RAS/TP53 and APC/PIK3CA have emerged as important biomarkers that determine an individual patient's tumour biology and may be used to predict outcome after CLM resection.

CONCLUSION

Knowledge of somatic mutations can guide the use of preoperative therapy, extent of surgical margin and selection for ablation alone.

Prognostic value of carbohydrate antigen 19-9 in patients undergoing resection of biliary tract cancer

BACKGROUND

The clinical significance of abnormally high levels of carbohydrate antigen (CA) 19-9 after resection of biliary tract cancer (BTC) is not well established. The aim of this study was to determine the prognostic value of CA19-9 normalization in patients undergoing resection of BTC with curative intent.

METHODS

Patients with BTC undergoing resection with curative intent (1996-2015) were divided into those with normal preoperative CA19-9 level (normal CA19-9 group), those with an abnormally high preoperative CA19-9 level (over 37 units/ml) and normal postoperative CA19-9 level (normalization group), and those with an abnormally high preoperative CA19-9 level and abnormally high postoperative CA19-9 level (non-normalization group). Overall survival (OS) was analysed and predictors of OS were determined.

RESULTS

The normal CA19-9 group (180 patients) and normalization group (74) had better OS than the non-normalization group (58) (3-year OS rate 70·4, 73 and 31 per cent respectively; both P < 0·001). The normal CA19-9 and normalization groups had equivalent OS (P = 0·880). On multivariable analysis, factors associated with worse OS were lymph node metastases (hazard ratio (HR) 1·78; P = 0·014) and abnormally high postoperative CA19-9 level (HR 3·16; P < 0·001). In the normalization group, OS did not differ after R0 versus R1 resection (3-year OS rate 69 versus 62 per cent respectively; P = 0·372); in the non-normalization group, patients with R1 resection had worse OS (3-year OS rate 36 and 20 per cent for R0 and R1 respectively; P = 0·032).

CONCLUSION

Non-normalization of CA19-9 level after resection of BTC with curative intent was associated with worse OS. R1 resection was associated with a particularly poor prognosis when CA19-9 levels did not normalize.

Prognostic factors after resection of colorectal liver metastases following preoperative second-line chemotherapy: Impact of RAS mutations

BACKGROUND

After resection of colorectal liver metastases (CLM), RAS mutations are associated with modest survival benefit and second-line chemotherapy confers limited hope for cure.

OBJECTIVE

To evaluate the impact of RAS mutation after second-line chemotherapy for patients undergoing potentially curative liver resection for CLM.

METHODS

Among 1357 patients operated for CLM between January 2005 and November 2014, patients with known RAS mutational status were identified. Outcomes after second-line chemotherapy were analyzed by RAS status.

RESULTS

Among 635 patients undergoing resection of CLM, 46 received second-line chemotherapy before resection, including 14 patients (30%) with RAS mutations. Patients who received second-line chemotherapy had significantly larger and greater number of liver metastases and were more likely to undergo major hepatectomy. Median overall (OS) and recurrence free survival (RFS) were significantly worse among patients requiring second-line chemotherapy (OS: 44.4 vs. 61.1 months, p = 0.021; RFS: 7.3 vs. 12.0 months, p = 0.001). Among patients undergoing liver resection after second-line chemotherapy, RAS mutations were associated with worse median OS and RFS (OS: 35.2 vs. 60.7 months, p = 0.038; RFS: 3.6 vs. 8.3 months, p = 0.015). RAS mutation was the only independent factor associated with OS and RFS. All patients with RAS mutations recurred within 18 months. Among patients with RAS wild-type tumors, the receipt of second-line chemotherapy did not affect OS (p = 0.493).

CONCLUSION

Among patients undergoing resection of CLM after second-line chemotherapy, RAS mutational status is an independent predictor of survival and outweighs other factors to select patients for liver resection.

Synthesis and characteristics of chloroform-treated silicon carbide-derived carbon layers

The pores reduced for CDC layers synthesized using (d–f) bubbled chloroform compared to that of (a–c) chlorine gas.

Preoperative or postoperative therapy for resectable gallbladder cancer? A retrospective analysis of patients treated at a single institution

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Background: Gallbladder cancer (GBC) is the most common malignancy of the biliary tract. Less than 30% present at an early stage where surgical resection is curative. We examine a cohort of patients with GBC toward determining if preoperative and postoperative treatment of locally advanced GBC demonstrate any differing results in complications or survival.

Methods: A retrospective review of patients seen at FCCC with GBC from Jan 1991 to Nov 2008 was performed. Demographics, clinical stage, surgical procedure, AJCC 7th stage, details of neoadjuvant and adjuvant treatment and complications of surgery were analyzed.

Results: Fifty-one patients with GBC were identified. Of these, 66% had their GBC found incidentally, 77% had stage 2 or greater cancers, and 35 patients needed liver resection with portal lymphadenectomy. 13 patients had an extrahepatic bile duct resection. 10 patients had extended resections including pancreatoduodenectomy (5) or colectomy (5), while 6 had cholecystectomy alone. 25% (n=13) of the population had preoperative chemoradiation only, 30 % (n=15) had postoperative chemoradiation only, while 15% (n=8) received maintenance chemotherapy only. 10% (n=5) had preoperative and postoperative therapy, while twenty percent of the group (n=10) had surgery only. 49% had recurrences (n=25), with 48% percent of these being local-regional. Median survival was 30 months for the whole group, with 54.6 month median survival for the 41 patients without extended resection. No significant difference in survival was seen comparing preoperative therapy versus postoperative treatment (p=0.13). Five-year survival is 47% for those with minor hepatic resection compared to 25% for those with combined hepatic and colon or pancreatic resection.

Conclusions: We present a retrospective view of patients treated in our center, the majority of whom received either preoperative or postoperative adjuvant therapy, both of which had good median survival and acceptable morbidity and mortality. Given the poor survival and high recurrence rate for stage II and greater cancers, we suggest that preoperative or postoperative adjuvant therapy for these cases may be equally effective.

No significant financial relationships to disclose.

Abstract P2-07-04: Relevance of Mutated PIK3CA to Normal Mammary Gland Development and Malignancy

In the current study we generated transgenic mice with mammary gland specific-overexpression of PI3KCA wild type and mutant protein with the aim to characterize the effects of activation of PI3K signaling on normal mammary gland and tumor development. PIK3CA encodes p110α, the predominant isoform of the catalytic subunit of class 1A phosphatidylinositol 3-kinase (PI3K), a lipid phosphokinase. The family of PI3Ks provides signaling for diverse cellular functions, including proliferation, metabolism, migration, translation, apoptosis avoidance, and angiogenesis. Disruption of this tightly regulated pathway by gene loss (PTEN), mutation (PIK3CA, AKT1, or less commonly PIK3R1), or amplification (PIK3CA), is one of the most common alterations in human cancers. PIK3CA mutations result in constitutive activation of p110α , increasing lipid kinase activity and resulting in an increase in activated AKT. The majority of mutations in breast cancer occur at three hotspots: E542K and E545K at exon 9, which encodes the helical domain, and H1047R at exon 20, which encodes the kinase domain. Previously, it was described that human mammary epithelial cells expressing these alleles grew efficiently in soft agar and as orthotopic tumors in nude mice. In a mouse model in which PI3K is activated by forced recruitment of p110α to the membrane, increased ductal branching, alveolar hyperplasia, intraductal neoplasia and a low frequency of mammary tumors were observed. In breast carcinoma, mutations in PIK3CA and loss of PTEN function are almost always mutually exclusive. However, mutations in PIK3CA are often correlated with overexpression of Her2/neu (48%) in primary breast carcinomas, indicating that gain of function in these two signaling components could have a synergistic effect in counteracting PTEN. To date, no in vivo studies have been reported to determine if PIK3CA mutations play a causative role in breast tumorigenesis. In the current study we generated transgenic mice with mammary gland specific-overexpression of PIK3CA wild type and mutant protein and analyzed the effects of activation of PI3K signaling on normal mammary gland and tumor development. Mice harboring Exon 9 and Exon 20 mutations showed increased ductal branching at 8 weeks of age. Two mice harboring low and high copy numbers of Exon 20 mutation developed mammary tumors at 14 and 16 months of age, respectively. Histological analysis revealed that both were carcinomas with tubular, papillary and comedo features. PI3K activation increases the mammary epithelial stem cell population (CD24med/CD49f hi) in the normal gland. This population, which was characterized both by in vitro and in vivo assays, is highly expanded in the tumor cells. Tumor formation and mammary gland development is being observed in PIK3CA mutants crossed with MMTV-Her2neu mice. In conclusion, PI3K signaling activation appears to alter normal mammary gland development and initiate mammary tumor formation.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-07-04.

Radioisotope synoviorthesis with Holmium-166-chitosan complex in haemophilic arthropathy

Radiosynoviorthesis is a safe and easy method for synovectomy in haemophilic arthropathy. Various agents have been used in radiosynoviorthesis, especially newly developed agent Holmium-166-chitosan complex has good clinical outcome. This study analysed clinical results and radiologic evaluation of radioisotope synoviorthesis using Holmium-166-chitosan complex in haemophilic arthropathy. From March 2001 to December 2003, 58 radiosynoviorthesis were performed in 53 haemophiliacs. The average age at procedure was 13.8 years. The Arnold and Hilgartner stage of the patients was from I to IV. Holmium-166-chitosan complex was injected in 31 ankle joints, 19 elbow joints and 8 knee joints. Average follow-up was 33 months since primary procedure. The range of motion of each joint, frequency of intra-articular bleeding and factor dose used were analysed for clinical assessment. There was no significant improvement of range of motion in affected joints. After procedure, the average frequency of bleeding of the elbow joint has decreased from 3.76 to 0.47 times per month, the knee joint from 5.87 to 1.12 times per month, and the ankle joint from 3.62 to 0.73 times per month respectively (P < 0.05). After treatment, the average coagulation factor dose injected was significantly decreased to 779.3 units per month from 2814.8 units per month before treatment (P < 0.001). Radioisotope synoviorthesis with Holmium-166-chitosan complex in haemophilic arthropathy is a very safe and simple procedure with the expectation of a satisfactory outcome without serious complication. It has excellent bleeding control effect on target joint and the need for substitution of coagulation factor concentrate can be reduced.

Comparison of cortical bone thickness and root proximity at maxillary and mandibular interradicular sites for orthodontic mini-implant placement

OBJECTIVES

To compare maxillary and mandibular cortical bone thickness and rootic proximity for optimal mini-implant placement.

SETTING AND SAMPLE POPULATION

CT images from 14 men and 14 women were used to evaluate buccal interradicular cortical bone thickness and root proximity from mesial of the central incisor to the 2nd molar. Cortical bone thickness was measured at 0 degrees , 15 degrees , 30 degrees , and 45 degrees angles relative to the root surface using three-dimensional images.

RESULTS

For the cortical bone thickness, there was no statistically significant difference between the maxilla and the mandible in the anterior area; however, there was a significant difference in the posterior area. Cortical bone in the maxilla, mesial and distal to canine interradicular sites, was thickest while thickness in the mandible exhibited a gradual anterior to posterior increase. Cortical bone thickness in the maxilla increased as both level and angle increased, while the cortical bone thickness in the mandible was greatest at 4 mm from the alveolar crest. Root proximity mesial and distal to 2nd premolar interradicular sites was greatest.

CONCLUSION

Based on our results, cortical bone thickness depends on the interradicular site rather than sex or individual differences.

Bone density at interradicular sites: implications for orthodontic mini-implant placement

OBJECTIVES

Implant stability is primarily related to local bone density; Few studies have evaluated interradicular bone density related to mini-implant placement for orthodontic anchorage. Therefore, this study evaluated bone density differences between interradicular sites.

SETTING AND SAMPLE POPULATION

Computed tomographic (CT) images were obtained from 14 males and 14 females (mean age 27 years, range 23-35 years). Bone density in Hounsfield units (HU) was measured at 13 interradicular sites and four bone levels.

RESULTS

Bone densities in most areas were higher than 850 HU. Statistically significant differences in bone density were detected at different levels and sites. Bone densities in both maxilla and mandible significantly increased from the alveolar crest toward basal bone in posterior areas, while the opposite was observed in anterior areas. There were statistically significant differences in bone densities between the maxilla and mandible in posterior areas. Bone densities progressively increased from anterior to posterior areas in the mandible.

CONCLUSION

The results suggest that mini-implants for orthodontic anchorage may be effective when placed in most areas with equivalent bone density up to 6 mm apical to the alveolar crest. Site selection should be adjusted according to bone density assessment.

The interdental gingiva, a visible guide for placement of mini-implants

OBJECTIVES

To determine whether the tip of the interdental gingiva can serve as a visible guide for placement of mini-implants.

SETTING AND SAMPLE POPULATION

Computer tomography (CT) images from 15 males and 15 females (mean age 27 years, range: 23-35 years) were used to evaluate the distance from the tip of the interdental gingiva to the alveolar crest from the central incisor to the 1st molar. The distance from a reference point to the tip of interdental gingiva was recorded from study models using a caliper. The distance between the reference point and the alveolar crest was recorded using CT and added to the model recordings thus providing the distance from the tip of interdental gingiva to the alveolar crest for the various interdental sites. Two-way anova and Student-Newman-Keuls test for multiple comparisons were used for the statistical analysis.

RESULTS

There was no significant difference in the distance from the tip of interdental gingiva to the alveolar crest between maxilla and mandible. The distance between the tip of interdental gingiva and the alveolar crest at the central/lateral incisors was the shortest compared with that of other sites. There was also a statistically significant difference between the male and female groups except for the maxillary 2nd premolar/1st molar interradicular site.

CONCLUSION

The tip of interdental gingiva appears a reasonable visual guide for the placement of mini-implants for orthodontic anchorage.

Extending the frontiers of resectability in advanced colorectal cancer

AIM

To review the advances in the past decade that have enabled more patients with colorectal liver metastases (CRLM) to undergo curative hepatic resection.

METHODS

A comprehensive literature review and pertinent data published on advanced CRLM from The University of Texas M. D. Anderson Cancer Center were used for this review.

RESULTS

Criteria for resectability of CRLM have expanded with the advent of effective chemotherapy, improved surgical technique, and novel strategies such as preoperative volumetry, portal vein embolization, and two-stage hepatectomy. Despite the aggressiveness of these approaches to treating patients with advanced disease, recent series show an improvement in 5-year survival rate for patients with CRLM.

CONCLUSIONS

Advances in multidisciplinary management and careful patient selection have enabled more patients to undergo curative resection for CRLM, with corresponding improvement in survival rates.

HLA class II alleles predict recurrence and pattern of failure in early-stage melanoma patients

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Background: Prior reports have suggested a link between specific HLA class II alleles, including HLA-DRB1*1101, and melanoma recurrence. We therefore investigated the relationship between HLA class II alleles and clinical outcome in a large population of patients who presented with localized melanoma. Methods: HLA class II alleles were determined by typing of genomic DNA from patients who presented with localized melanoma (AJCC stage IA-IIC). Patients found to have occult regional disease by sentinel node biopsy were excluded. Log-rank and Cox analysis of outcome versus standard prognostic factors and common HLA class II alleles (=5% of the population) was performed. Results: 1,241 patients underwent HLA typing. The median primary tumor thickness was 1.1 mm, 16% were ulcerated, and the median follow-up was 56 months. Tumor thickness, ulceration, and Clark level were independent predictors of recurrence. The HLA class II allele HLA-DRB1*1101 (11% of the population) independently predicted a higher risk of recurrence [hazard ratio (HR) 2.04, P=0.004] while HLA-DRB1*0401 (20% of the population) predicted a lower risk of recurrence (HR 0.42, P=0.004). HLA- DRB1*1101 was a particularly strong predictor of recurrence in stage I patients (HR 2.73, P<0.0001). Among patients who recurred, HLA- DRB1*1101 was an independent predictor of local-regional vs. distant recurrence (HR 2.7, P=0.007), and was more common in those whose first recurrence was isolated to the regional nodal basin, compared to those whose first recurrence was elsewhere or in multiple locations (24% HLA-DRB1*1101-positive vs. 14%, P<0.009). Conclusions: These results confirm that HLA-DRB1*1101 is a genetic marker of increased risk of melanoma recurrence, while HLA-DRB1*0401 is a marker of decreased risk of recurrence. HLA-DRB1*1101 is a particularly strong marker among the group of patients predicted clinically to be at the lowest overall risk for recurrence, and independently predicts pattern of recurrence (regional nodal failure). This information is of value in the development of surveillance strategies for melanoma patients, as well as the selection, stratification and randomization of early-stage melanoma patients for clinical trials.

No significant financial relationships to disclose.

A new HIF-1 alpha variant induced by zinc ion suppresses HIF-1-mediated hypoxic responses

The expressions of hypoxia-inducible genes are upregulated by hypoxia-inducible factor 1 (HIF-1), which is a heterodimer of HIF-1α and HIF-1β/ARNT (aryl hydrocarbon receptor nuclear transporter). Under hypoxic conditions, HIF-1α becomes stabilized and both HIF-1α and ARNT are translocated into the nucleus and codimerized, binding to the HIF-1 consensus sequence and transactivating hypoxia-inducible genes. Other than hypoxia, cobalt and nickel, which can substitute for iron in the ferroprotein, induce the stabilization of HIF-1α and the activation of HIF-1. We found previously that, although zinc, another example of a metal substitute for iron, stabilized HIF-1α, it suppressed the formation of HIF-1 by blocking the nuclear translocation of ARNT. Here, we identify a new spliced variant of human HIF-1α that is induced by zinc. The isoform lacks the 12th exon, which produced a frame-shift and gave a shorter form of HIF-1α (557 amino acids), designated HIF-1αZ (HIF-1α induced by Zn). This moiety was found to inhibit HIF-1 activity and reduce mRNA expressions of the hypoxia-inducible genes. It blocked the nuclear translocation of ARNT but not that of endogenous HIF-1α, and was associated with ARNT in the cytosol. These results suggest that HIF-1αZ functions as a dominant-negative isoform of HIF-1 by sequestering ARNT in the cytosol. In addition, the generation of HIF-1αZ seems to be responsible for the inhibitory effects of the zinc ion on HIF-1-mediated hypoxic responses, because the expressed HIF-1αZ behaved in the same manner as zinc in terms of inhibited HIF-1 activity and ARNT translocation.

Induction of Fas and Fas ligand expression on malignant glioma cells by Kupffer cells, a potential pathway of antiliver metastases

Kupffer cells play an important role in controlling the growth and development of liver metastases. However, the pathway of Kupffer cells against tumor metastases is not clear. In the present study, we set up an experimental model to investigate the mechanisms on how Kupffer cells kill tumor cells which metastasize to the liver. Malignant glioma cells were cocultured with Kupffer cells or treated with culture medium collected from lipopolysaccharide (LPS)-activated Kupffer cells. The results showed that the interaction between Kupffer cells and malignant glioma cells significantly stimulated the generation of tumor necrosis factoralpha (TNFalpha). TNFalpha was mainly produced by Kupffer cells, as its level in culture medium obtained from LPS-treated Kupffer cells was not significantly different from that of malignant glioma cells treated with the same medium. Both Kupffer cells and LPS/Kupffer cell-conditioned supernatants induced expression of Fas and Fas ligand on malignant glioma cells. Subsequently a significant proportion of malignant glioma cells became apoptotic, as evidenced by positive staining of annexin V and propidium iodine and an increase in cellular DNA fragmentation. Therefore, this study supports a novel pathway of Kupffer cells against liver metastases, in which tumor cells were apoptotic via the Fas-Fas ligand system induced by TNFalpha released from Kupffer cells.

The clinical and ocular manifestations of Takayasu arteritis

PURPOSE

To evaluate the clinical and ocular manifestations of Takayasu arteritis and the fundus fluorescein angiography (FFA) characteristics of Takayasu retinopathy (TR).

PATIENTS AND METHODS

Medical records and fundus fluorescein angiograms of 156 eyes of 78 patients with Takayasu arteritis were reviewed. Fundus FA using a wide-field fundus camera (60 degrees) was performed in 19 patients, and conventional angiography or spiral computed tomographic angiography was performed in all 78 patients.

RESULTS

The series included 67 female and 11 male patients; mean age at time of diagnosis was 26.7 years (range, 4-61 years). Hypertension was found in 44 (56.4%) patients, ischemic cerebrovascular symptoms in 18 (23.1%) patients, and amaurosis fugax in 20 (25.6%) patients. On fundus examination, no retinopathy was found in 87 (55.8%) eyes; hypertensive retinopathy was found in 48 (30.8%) eyes; and TR was found in 21 (13.5%) eyes. Patients with TR had carotid artery or aortic arch involvement, and patients with hypertensive retinopathy had involvement of the descending aorta or renal artery and sparing of the carotids. Best-corrected visual acuity in TR Stage 1 to 3 ranged from 20/15 to 20/30, but in Stage 4, it ranged from 20/200 to hand motions because of secondary ocular complications. On FFA, the arm-to-retina circulation time was prolonged in all 21 eyes with TR (mean, 22.7+/-8.9 seconds), but only 14 eyes showed delayed arteriovenous filling time, which was mainly found in chronic, moderate to severe TR, Stage 3 or 4. Arteriovenous anastomosis was found in all 12 eyes with Stage 3 and 4 TR.

CONCLUSIONS

Delayed arm-to-retina circulation time is shown in all cases of TR, but delayed arteriovenous filling time is mostly found in moderate and severe TR. During ophthalmic examination, the delay of arteriovenous filling time and formation of arteriovenous anastomosis must be examined carefully to prevent visual deterioration.

Germline E-cadherin gene mutations: is prophylactic total gastrectomy indicated?

BACKGROUND

The CDH1 gene encodes E-cadherin, an epithelial cell adhesion molecule. Germline CDH1 mutations recently were identified in families with hereditary diffuse gastric carcinoma in a pattern suggestive of autosomal dominant inheritance with incomplete penetrance.

METHODS

The proband was a woman age 47 years with a strong family history of diffuse gastric carcinoma. A germline E-cadherin gene mutation was identified in this patient, her brother, and three first cousins. All five family members underwent endoscopic evaluations, which were negative for malignancy, and elected to undergo a prophylactic total gastrectomy with Roux-en-Y esophagojejunostomy.

RESULTS

Pathologic examination of the proband's stomach revealed several microscopic foci of intramucosal signet ring cell adenocarcinoma in the cardia and proximal gastric body. Postgastrectomy specimens from the proband's brother and three first cousins all showed intramucosal signet ring cell adenocarcinoma in various regions of the stomach. Immunoperoxidase studies performed on gastric tissue from these five patients demonstrated diminished or absent E-cadherin reactivity in the cancerous mucosa.

CONCLUSIONS

Although total gastrectomy was performed as a prophylactic intervention, occult gastric carcinoma was discovered in all five patients. Thus, total gastrectomy should be curative for gastric carcinoma in these patients. Based on their successful outcomes and the lack of efficacious surveillance methods for diffuse gastric carcinoma, prophylactic total gastrectomy may be the management of choice for germline E-cadherin gene mutation carriers. However, prophylactic total gastrectomy should be undertaken cautiously because the procedure may be associated with considerable morbidity.

Germline E-cadherin gene mutations: is prophylactic total gastrectomy indicated?

BACKGROUND

The CDH1 gene encodes E-cadherin, an epithelial cell adhesion molecule. Germline CDH1 mutations recently were identified in families with hereditary diffuse gastric carcinoma in a pattern suggestive of autosomal dominant inheritance with incomplete penetrance.

METHODS

The proband was a woman age 47 years with a strong family history of diffuse gastric carcinoma. A germline E-cadherin gene mutation was identified in this patient, her brother, and three first cousins. All five family members underwent endoscopic evaluations, which were negative for malignancy, and elected to undergo a prophylactic total gastrectomy with Roux-en-Y esophagojejunostomy.

RESULTS

Pathologic examination of the proband's stomach revealed several microscopic foci of intramucosal signet ring cell adenocarcinoma in the cardia and proximal gastric body. Postgastrectomy specimens from the proband's brother and three first cousins all showed intramucosal signet ring cell adenocarcinoma in various regions of the stomach. Immunoperoxidase studies performed on gastric tissue from these five patients demonstrated diminished or absent E-cadherin reactivity in the cancerous mucosa.

CONCLUSIONS

Although total gastrectomy was performed as a prophylactic intervention, occult gastric carcinoma was discovered in all five patients. Thus, total gastrectomy should be curative for gastric carcinoma in these patients. Based on their successful outcomes and the lack of efficacious surveillance methods for diffuse gastric carcinoma, prophylactic total gastrectomy may be the management of choice for germline E-cadherin gene mutation carriers. However, prophylactic total gastrectomy should be undertaken cautiously because the procedure may be associated with considerable morbidity.

Hyperbaric oxygenation pretreatment induces catalase and reduces infarct size in ischemic rat myocardium

Ischemia-reperfusion injury is a major complication occurring in heart stroke, cardiopulmonary bypass surgeries, and heart transplantation. Reactive oxygen species generated during the reperfusion phase overwhelm the scavenging capacities of antioxidant enzymes, and result in oxidative damage to the myocardium. We examined whether hyperbaric oxygenation (HBO) pretreatment induces antioxidant enzymes and protects the heart from subsequent ischemia-reperfusion injury. Rats were intermittently exposed to 100% O2 at 3 ATA (where ATA is absolute atmosphere) for 1 h daily and then sacrificed after 24 h of recovery in room air. Isolated hearts were subjected to 40 min of ischemia and 90 min of reperfusion. HBO pretreatment was found to condition the heart and enhance enzymatic activity and gene expression of catalase, thereby significantly reducing infarct size after reperfusion. A catalase inhibitor, 3-amino-1,2,4-triazole, completely abolished the infarct-limiting effect of HBO pretreatment, which suggests that HBO-induced tolerance against ischemia-reperfusion injury is due to catalase induction. Our results imply that HBO preconditioning may be developed as a new preventive measure for reperfusion injury in the heart.

Lipoblastoma

BACKGROUND/PURPOSE

Lipoblastoma is a rare benign mesenchymal tumor of embryonal fat that occurs almost exclusively in infants and children. This study was done to determine the clinical and pathologic characteristics of lipoblastoma.

METHODS

Nine cases of pathologically proven lipoblastoma from 1979 to 1997 were reviewed. There were 6 boys and 3 girls ranging in age from 3 months to 29 months.

RESULTS

A soft tissue mass was the chief complaint in 7 patients, abdominal distension in 1 patient with a retroperitoneal mass, and defecation difficulty in 1 patient with a perirectal mass. In 4 patients, tumors occurred on the back. Other tumor location includes the neck, scrotum, retroperitoneum, perirectal area, and buttock in 1 patient each. Lesions measured 2.3 to 19.5 cm. Complete excision was done in 8 patients. One perirectal tumor was removed by both the posterior sagittal approach and the intraabdominal approach but incompletely resected. Two tumors located on the back recurred with intraspinal extension 12 months and 18 months after resection. Second resection and second resection with laminectomy were done. Leg pain and urinary incontinence developed in 1 patient but improved on conservative treatment.

CONCLUSIONS

Lipoblastoma is a benign neoplasm but can frequently recur (25%) in spite of complete excision. Lipoblastomas occurring on the back had a high recurrence rate (50%) and associated with intraspinal extension. J Pediatr Surg 36:905-907.

Inhibitory effect of YC-1 on the hypoxic induction of erythropoietin and vascular endothelial growth factor in Hep3B cells

YC-1 is a newly developed agent that inhibits platelet aggregation and vascular contraction. Although its effects are independent of nitric oxide (NO), it mimics some of the biological actions of NO. For example, it stimulates soluble guanylate cyclase (sGC) and increases intracellular cGMP concentration. Here, we tested the possibility that YC-1 inhibits hypoxia-inducible factor (HIF)-1-mediated hypoxic responses, as does NO. Hep3B cells were used during the course of this work to observe hypoxic induction of erythropoietin (EPO) and vascular endothelial growth factor (VEGF), and the effects of YC-1 were compared with those of a NO donor, sodium nitropurruside (SNP). In hypoxic cells, YC-1 blocked the induction of EPO and VEGF mRNAs, and inhibited the DNA-binding activity of HIF-1. It suppressed the hypoxic accumulation of HIF-1alpha, but not its mRNA level. It also reduced HIF-1alpha accumulation induced by cobalt and desferrioxamine. Treatment with antioxidants did not recover the HIF-1alpha suppressed by YC-1. We examined whether these effects of YC-1 are related to the sGC/cGMP signal transduction system. Two sGC inhibitors examined failed to block the effects of YC-1, and 8-bromo-cGMP did not mimic actions of YC-1. The effects of YC-1 on the hypoxic responses were comparable with those of SNP. These results suggest that YC-1 and SNP suppressed the hypoxic responses by post-translationally inhibiting HIF-1alpha accumulation. The YC-1 effect may be linked with the metal-related oxygen sensing pathway, and is not due to the stimulation of sGC. This observation implies that the inhibitory effects of YC-1 on hypoxic responses can be developed to suppress EPO-overproduction by tumor cells and tumor angiogenesis.

A comparison between friction and frictionless mechanics with a new typodont simulation system

This study was designed to explore the differences between friction and frictionless mechanics for maxillary canine retraction with the use of a new typodont simulation system, the Calorific machine system. The unit was designed to observe the whole process of tooth movement and is composed of 3 parts: a temperature regulating system, electrothermodynamic teeth, and an artificial alveolar bone component. The efficiency of maxillary canine retraction was compared with the sliding mechanics (along a.016 x.022-in stainless steel labial arch and nickel-titanium closed coil spring) and a canine retraction spring. The patterns of tooth movement obtained with both of these mechanics were measured 5 times each. Friction mechanics were superior to frictionless mechanics in terms of rotational control and dimensional maintenance of the arch (P <.0001); frictionless mechanics were shown to be more effective at reducing tipping and extrusion (P <.0001). However, the observed differences between the 2 methods were relatively small in terms of their clinical significance, and no differences were found in anchorage control (P =.2078). In conclusion, this study indicated that friction and frictionless mechanics perform similarly.

A case of cutaneous reaction to chemotherapeutic agents showing epidermal dysmaturation

Cutaneous chemotherapy reactions are more likely to be toxic than allergic. Epidermal dysmaturation refers to histologic changes that may be observed in the epidermis after any significant cytoreductive therapy. We report a case of epidermal dysmaturation occurring in a patient with acute myelogenous leukemia after antineoplastic chemotherapy.

A sds22 homolog that is associated with the testis-specific serine/threonine protein phosphatase 1gamma2 in rat testis

Two cDNAs sequences (1320 bp and 1180 bp) of the 55-kDa subunit associated with a testis-specific serine/threonine protein phosphatase 1gamma2 (PP1gamma2) were cloned. They were the same up to 1180 bp, suggesting that they may be generated by alternative splicing. Sequence studies showed that the 1320 bp-cDNA is a homolog of the human sds22alpha(1) (thus, named rat sds22alpha(1)). The 1180 bp-cDNA is a new splice-variant since its sequence at the 3' end has not been identified in human sds22 genes (named rat sds22alpha(3)). The 1320 bp-cDNA is ubiquitously expressed in various tissues including the immature testis. However, the expression of 1180 bp-cDNA was only observed in the testis after puberty. This expression pattern matches very well with that of PP1gamma2, suggesting that 1180 bp-cDNA may encode the 55-kDa subunit to associate with PP1gamma2 in rat testis and is involved in spermatogenesis by controlling PP1gamma2 activity.

Cadmium blocks hypoxia-inducible factor (HIF)-1-mediated response to hypoxia by stimulating the proteasome-dependent degradation of HIF-1alpha

Cadmium is a substantial industrial and environmental pollutant which seriously impairs erythropoiesis. Cd has been demonstrated to aggravate anemia by suppressing erythropoietin gene expression in anemic patients. As hypoxic induction of erythropoietin mRNA depends on a transcription factor, hypoxia-inducible factor 1 (HIF-1), we hypothesized that Cd suppresses the hypoxic activation of HIF-1. In hypoxic Hep3B cells, all mRNAs of various genes, which are known to be upregulated by HIF-1 activation under hypoxia, were suppressed by Cd in a dose-dependent manner. Cd inhibited the hypoxia-induced activity of luciferase in 293 cells which was transfected with a reporter plasmid carrying a hypoxia response element. By electrophoretic mobility gel shift assay, Cd inhibited the DNA-binding activity of HIF-1 in hypoxic Hep3B cells. Cd reduced the amount of HIF-1alpha protein in hypoxia, whereas it didn't affect HIF-1 alpha mRNA levels. Moreover, Cd inhibited HIF-1alpha accumulation induced by cobalt and desferrioxamine. Antioxidants and a proteasome inhibitor prevented the HIF-1alpha degradation caused by Cd. The possibility that oxidative stress mediates this action of Cd was examined. Cd didn't affect protein oxidation and reduced glutathione levels in hypoxic cells. These results indicate that Cd triggers a redox/proteasome-dependent degradation of HIF-1alpha protein, reducing HIF-1 activity and in turn suppressing the hypoxic induction of hypoxia-inducible genes.

Cytoprotective effect of arginine deiminase on taxol-induced apoptosis in DU145 human prostate cancer cells

We purified and partially sequenced a cytostatic protein from the ASC-17D Sertoli cell-conditioned media (rSCCM) showing a molecular weight of 90 kDa with homodimeric composition. N-terminal amino acid analysis revealed that the protein was homologous to the arginine deiminase (ADI) of Mycoplasma arginini. We found ADI enzyme activity in rSCCM and the abolishment of the growth inhibitory effect by the supplement of L-arginine. Thus, we confirmed that the cytostatic activity in rSCCM was due to the depletion of extracellular L-arginine by ADI. Apparent increase of cell death or DNA fragmentation was not observed in DU145 cells cultured in the presence of ADI. Incubation of DU145 cancer cells with taxol resulted in a marked DNA fragmentation, whereas pretreatment with ADI or cycloheximide protected the cells from taxol-induced apoptosis. Preincubation of the cells with ADI inhibited S35-methionine incorporation into protein synthesis in a dose dependent manner. These data suggest that ADI-induced arginine depletion may inhibit protein synthesis, and result in the protection of apoptotic cell death that requires new protein synthesis.

Clinical and histopathologic characteristics of trichrome vitiligo

BACKGROUND

The term trichrome vitiligo describes lesions that have a tan zone of varying width between normal and totally depigmented skin, which exhibits an intermediate hue. However, the pathogenesis and the histopathologic characteristics of trichrome vitiligo are unknown.

OBJECTIVE

Our purpose was to investigate the clinical and histopathologic characteristics and the pathogenesis of trichrome vitiligo.

METHODS

Four punch biopsy specimens were taken from 21 patients with trichrome vitiligo; they were from vitiliginous skin, light brown skin, perilesional normal skin, and normal skin as far as 5 cm from the nearest vitiligo spot. The sections were stained with hematoxylin-eosin; in selected cases, we performed immunohistochemical staining with S-100 protein and CD1a.

RESULTS

Trichrome vitiligo occurred most frequently on the trunk in active vitiligo vulgaris. Focal vacuolar degeneration of the basal cell layer and mild inflammatory cell infiltration of the epidermis and dermis were more prominent in light brown skin and perilesional normal skin than in vitiliginous skin and normal skin. The number of melanocytes was decreased in light brown skin compared with perilesional normal skin (P <.05) and in vitiliginous skin compared with light brown skin (P <.05); a few melanocytes were observed even in skin affected by trichrome vitiligo. The number of Langerhans cells was increased in the epidermis of light brown skin and perilesional normal skin compared with vitiliginous and normal skin (P <.05). PUVA therapy yielded excellent repigmentation.

CONCLUSION

Trichrome vitiligo is a variant of active vitiligo. The changes of melanocytes, keratinocytes, and Langerhans cells may be involved in the pathogenesis of depigmentation in trichrome vitiligo.

Zinc induces the accumulation of hypoxia-inducible factor (HIF)-1alpha, but inhibits the nuclear translocation of HIF-1beta, causing HIF-1 inactivation

The replacement of heme iron by cobalt or nickel in a putative oxygen sensor is supposed to reduce oxygen binding to the heme protein, resulting in HIF-1 activation and erythropoietin (EPO) induction. According to this hypothesis, zinc might be another example of a transition metal which is capable of stimulating EPO production. By substituting for heme iron, zinc protoporphyrin IX is produced, which has a known low oxygen affinity. However, it has been reported that zinc fails to induce EPO in normoxia, and that it suppresses EPO production in hypoxic cells. This unexpected effect of zinc on EPO production is not understood. In this study, we found that zinc induced the accumulation and nuclear translocation of hypoxia-inducible factor (HIF)-1alpha but inhibited the nuclear translocation of HIF-1beta, which inactivated HIF-1 and suppressed EPO mRNA induction in hypoxic cells.

A case of linear scleroderma and myasthenia gravis

We report a case of a 28-year-old woman with myasthenia gravis who developed linear scleroderma seven years later. Myasthenia gravis and scleroderma are rarely found in direct association with each other; there are only five such reported cases, all of which were systemic scleroderma patients. Although localized and systemic scleroderma are distinct entities, autoimmunity is believed to be involved in the pathogenesis of both. Myasthenia gravis and scleroderma may occur coincidentally, but an autoimmune predisposition seems to be the more likely underlying cause, as evidenced by an increased incidence of autoantibodies and autoimmune diseases.

Guanosine 5',3'-cyclic monophosphate enhances lipopolysaccharide-induced nitric oxide synthase expression in mixed glial cell cultures of rat

Primary mixed glial cell cultures treated with lipopolysaccharide (LPS; 1.0 microg/ml) showed biphasic increases of inducible nitric oxide synthase (iNOS) mRNA expression 6 h and 24-36 h after LPS treatment. Dibutyryl-guanosine 5',3'-cyclic monophosphate (db-cGMP; 1.0 mM) enhanced the second phase of the LPS-induced iNOS expression 24 and 30 h after LPS stimulation. KT5823 (1.0 microM), a protein kinase G (PKG) inhibitor, inhibited the LPS-induced iNOS expressions at 24 and 30 h and their enhancements caused by db-cGMP. In astrocyte-enriched cultures with reduced microglial contamination, the LPS-induced iNOS expression was decreased, though slightly enhanced by db-cGMP. These results suggest that cGMP/PKG signaling may be involved in the second phase of the LPS-induced glial iNOS expression and its upregulation, which are apparent in the presence of microglial cells.

Chronic pruritic papular dermatitis in adult men: a variant of prurigo

Chronic recurrent pruritic papular eruptions in which a specific diagnosis cannot be established becomes a baffling experience to the dermatologist. We have met adult male patients with chronic recurrent pruritic papular eruptions, but their clinicopathological features are not described in English language textbooks. Our purpose was to study the clinical and histological features of this entity and review the various existing taxonomy. We conducted a study of 20 patients over a six year period by taking histories, performing skin biopsies, screening patch tests, and doing immunofluoresence studies. The eruptions occurred exclusively in male adults and had a predilection for the trunk and proximal extremities. The lesions were characterized by severely pruritic, nonfollicular, monomorphic, erythematous urticarial papules. There was no evidence of atopic diathesis or history of insect bite. Most patients had normal levels of serum eosinophils and IgE. The predominant histopathologic finding was a presence of perivascular infiltration of mononuclear cells with eosinophils. The patients followed a chronic course of at least six months with waxing and waning; systemic corticosteroids were the only effective treatment. Finally, all other pruritic erythematous papular dermatoses were ruled out. These cases comprise a distinct entity that has previously been mentioned in a few reports. Clear definition of this entity with an appropriate designation is in order to avoid confusion among dermatologists, and we propose the disease name "chronic papular dermatitis in adult men" as a variant of prurigo.

Role of the 78-kDa glucose-regulated protein as an activity modulator of protein phosphatase1gamma2

We have previously found the 78-kDa glucose-regulated protein (Grp78) to be a subunit of protein phosphatase1(PP1)gamma2. To determine the role of Grp78 in PP1gamma2 holoenzyme, we compared the two forms of this enzyme, PP1gamma2 holoenzyme containing Grp78 and Grp78-dissociated PP1gamma2 in rat testes in terms of their kinetic constants and sensitivities to inhibitors of this enzyme. The enzymatic activity of the Grp78-dissociated enzyme was much lower at whole range of concentrations of a substrate (phosphorylase a) than that of the holoenzyme; the Km value was about ten-fold higher in Grp78-dissociated enzyme than in holoenzyme, while the Vmax was similar. IC50s of the Grp78-dissociated enzyme for three inhibitors (microcystin-LR, inhibitor-2, and okadaic acid) were more than ten-fold higher than those of the holoenzyme. These results indicate that the Grp78 subunit modulates the activity of PP1gamma2 through its actions to control the binding of substrates or inhibitors to PP1gamma2.

A case of classical Kaposi's sarcoma of the penis showing a good response to high-energy pulsed carbon dioxide laser therapy

Isolated Kaposi's sarcoma (KS) of the glans penis is rare; only 37 cases are reported in the literature. Treatment of KS consists mostly of old modalities, some old methods in updated improved versions, and some new and experimental therapies. We report a case of isolated classical Kaposi's sarcoma involving multiple sites of the penis in a 54-year-old man who was treated with high-energy pulsed carbon dioxide (CO2) laser therapy, resulting in complete resolution of the lesions and no evidence of recurrence.

Nevus depigmentosus: clinical features and histopathologic characteristics in 67 patients

BACKGROUND

Nevus depigmentosus is defined as a congenital nonprogressive hypopigmented macule or patch that is stable in its relative size and distribution throughout life. The pathogenesis and histopathologic characteristics of nevus depigmentosus is not yet fully established.

OBJECTIVE

The purpose of this study was to investigate the clinical and histopathologic characteristics of nevus depigmentosus as well as its pathogenesis.

METHODS

A clinical survey was done with 67 patients diagnosed as having nevus depigmentosus. Two skin biopsy specimens each were taken from 18 patients: one from the central part of the depigmented lesion and another from the border of the lesion, including perilesional normal skin. The sections were stained with hematoxylin-eosin, Fontana-Masson, and S-100 protein. Ultrastructural evaluation was also done to detect changes of the melanocytes.

RESULTS

The lesions were mostly present before 3 years of age (92.5%), but some lesions also appeared later in childhood (7.5%). The back and buttocks were the most commonly affected sites, followed by the chest and the abdomen, the face, the neck, and the arms. Forty patients (59.7%) had the isolated type of nevus depigmentosus and 27 patients (40.3%) had the segmental type. Histopathologic studies showed that the staining ability of Fontana-Masson in nevus depigmentosus lesions decreased compared with perilesional normal skin. However, there were no changes in the numbers of melanocytes identified as S-100-positive cells in the basal layer. Electronmicroscopic studies revealed a great reduction in the number of melanosomes in melanocytes and some membrane-bound aggregated melanosomes were observed in keratinocytes.

CONCLUSION

The results of this study support the hypothesis that nevus depigmentosus is caused by the functional defects of melanocytes and the morphologic abnormalities of melanosomes.

Visual method of measuring reflection-type characteristics of holographic optical elements

A highly diverging laser beam is used to measure angular and spectral selectivities and grating vector direction for reflection-type holographic optical elements (HOE's). The intensity distribution of the beam transmitted from the HOE's reveals dark, ring-shaped patterns. Since these ring patterns are formed as a result of the beam diffracted by the HOE's, the thicknesses and the diameters of the ring patterns convey information on both the angular and the spectral selectivities of the HOE's. In addition the deviation of the ring centers relative to the center of the intensity distribution reveals the grating vector direction. Determination of values related to the ring patterns permits highly accurate measurement of HOE characteristics, such as the upper limit of the diffraction wavelength, the angular and the spectral selectivities, and the grating vector direction. This is proved experimentally.