Alterations of the p16INK4a/p14ARF pathway in clear cell sarcoma

Clear cell sarcoma (CCS) is a very rare soft tissue sarcoma with a poor prognosis. It has become apparent through immunohistochemical, ultrastructural, and microarray analyses that CCS is a soft tissue melanocytic neoplasm. Alterations in the p16INK4a/p14ARF gene are common in malignant melanoma, which is the prototypical melanocytic neoplasm. In the present study, we performed a clinicopathologic analysis and investigated p16 and cyclin D1 expression by immunohistochemistry in 14 cases. Furthermore, we investigated genetic changes of various tumor suppressor genes and an oncogene, including p16INK4a/p14ARF, p53, beta-catenin, and APC, in 11 cases. The 5-year overall survival rate in all the patients was 33.3%. A high mitotic rate was a significant adverse prognostic factor (P = 0.004). Decreased expression of p16 was observed in 4 (28.6%) of 14 cases. Overexpression of cyclin D1 was observed in 9 cases (64.3%). SSCP analysis followed by DNA direct sequencing revealed point mutations of the p16INK4a gene in 2 of 11 cases (18.2%). In addition, one case with the p14ARF mutation and 2 cases with the p53 mutation were observed. None of the cases harbored mutation of the beta-catenin or APC gene. Homozygous deletion of the p16INK4a/p14ARF gene was detected in one case. Methylation-specific PCR did not reveal hypermethylation of the p16INK4a/p14ARF promoter region in any of the cases. Three cases harbored genetic alterations of the p16INK4a/p14ARF gene (27.3%). All tumors with genetic alterations of the p16INK4a/p14ARF or p53 gene showed a high mitotic rate or tumor necrosis. These alterations were considered to be influential in the poor prognosis of CCS patients.     

Optimal entry position on the lateral femoral surface for outside-in drilling technique to restore the anatomical footprint of anterior cruciate ligament

Purpose

To investigate the optimal starting points for drilling on the lateral femoral condyle for better coverage of the anatomical footprint of the anterior cruciate ligament (ACL) using the outside-in (OI) technique in a single-bundle ACL reconstruction.

Methods

Femoral tunnel drilling was simulated on three-dimensional bone models from 40 subjects by connecting the centre of the ACL footprint with various points on the lateral femoral surface. The percentage of the femoral footprint covered by apertures of the virtual tunnel sockets with 9 mm diameter was calculated for each tunnel.

Results

The mean percentages of the femoral footprint covered by the apertures of the virtual tunnel sockets were significantly higher when drilled at 2 and 3 cm from the lateral epicondyle on a 45° line and a 60° line anterior from the proximal–distal axis than the other points. However, articular cartilage damage was occurred in nine subjects at 3 cm on a 60° line and eight subjects at 3 cm on a 45° line. Posterior wall blowout occurred in five subjects at 3 cm on a 45° line. Thus, OI drilling at 3 cm from the epicondyle has a risk of these complications.

Conclusion

During the OI drilling of the femoral tunnel, connecting the centre of the anatomical footprint of the ACL and the entry drilling point at 2 cm from the lateral epicondyle on between the 45° line and the 60° line anterior from the proximal–distal axis provides an oval-shaped socket aperture that covers and restores the native ACL footprint as nearly as possible.

Level of evidence

III.

     

Characteristic methylation profile in CpG island methylator phenotype‐negative distal colorectal cancers

Aberrant DNA methylation is involved in colon carcinogenesis. Although the CpG island methylator phenotype (CIMP) is defined as a subset of colorectal cancers (CRCs) with remarkably high levels of DNA methylation, it is not known whether epigenetic processes are also involved in CIMP‐negative tumors. We analyzed the DNA methylation profiles of 94 CRCs and their corresponding normal‐appearing colonic mucosa with 11 different markers, including the five classical CIMP markers. The CIMP markers were frequently methylated in proximal CRCs (p < 0.01); however, RASSF1A methylation levels were significantly higher in distal CRCs, the majority of which are CIMP‐negative (p < 0.05). Similarly, methylation levels of RASSF1A and SFRP1 in the normal‐appearing mucosae of distal CRC cases were significantly higher than those in the proximal CRC cases (p < 0.05). They were also positively correlated with age (RASSF1A, p < 0.01; SFRP1, p < 0.01). Microarray‐based genome‐wide DNA methylation analysis of 18 CRCs revealed that 168 genes and 720 genes were preferentially methylated in CIMP‐negative distal CRCs and CIMP‐positive CRCs, respectively. Interestingly, more than half of the hypermethylated genes in CIMP‐negative distal CRCs were also methylated in the normal‐appearing mucosae, indicating that hypermethylation in CIMP‐negative distal CRCs is more closely associated with age‐related methylation. By contrast, more than 60% of the hypermethylated genes in CIMP‐positive proximal CRCs were cancer specific (p < 0.01). These data altogether suggest that CpG island promoters appear to be methylated in different ways depending on location, a finding which may imply the presence of different mechanisms for the acquisition of epigenetic changes during colon tumorigenesis.     

A new surgical approach for control of pain in chronic pancreatitis: complete denervation of the pancreas

With the aim of pain control in chronic pancreatitis without the morbidity of insulin-dependent diabetes, a new procedure was devised to completely resect the postganglionic pancreatic nerves and to totally free the pancreas from the posterior abdominal wall. This procedure was performed on two patients with follow-up periods of 24 and 10 months. Pain was resolved in both patients, and their blood glucose levels were substantially unchanged. This new approach offers a means of relieving pain with preservation of endocrine function in selected patients with chronic pancreatitis, especially in patients who have a small pancreatic duct.     

Two subtypes of radiographic osteoarthritis in the distal interphalangeal joint of the hand

Background  The etiology and pathogenesis of hand osteoarthritis (OA) are not completely clarified, and several factors may cooperate in a multifactorial fashion in its development. The purpose of this study was to clarify the effects of the dominant hand that contribute to the development of distal interphalangeal (DIP) joint OA using epidemiological analyses. Methods  A total of 518 subjects (156 men, 362 women) in a rural community were analyzed. Their mean age was 63.8 years for men and 60.7 years for women. Anteroposterior (AP) standing radiographs of bilateral knees, lateral views of the lumbar spine, and AP views of bilateral hands were obtained. Furthermore, a survey of their life patterns was conducted using self-administered questionnaires. Radiographic osteoarthritis was defined as Kellgren and Lawrence grade 2 or higher. Hand OA was limited to Heberden’s nodes. Generalized OA (GOA) was defined as bilateral knee OA plus lumbar spine OA. Results  GOA was observed in 13.0% of the subjects. The incidence of DIP joint OA was significantly higher in the GOA group than that in the non-GOA group. In the GOA group, the incidence of right-hand DIP joint OA in right-handed and left-handed subjects was 37.5% and 40.0%, respectively, without a significant difference. In the non-GOA group, however, the incidence of right-hand DIP joint OA in right-handed and left-handed subjects was 16.4% and 3.2%, respectively, with a significant difference. With a multiple logistic regression model, the P value of the handedness was marginal (0.060), but a clear tendency of increase in the odds ratio (7.129) was observed in the dominant hand for the non- GOA group. In contrast, there was no effect of the handedness on right-hand DIP joint OA in the GOA group. Conclusions  There are two subtypes of hand DIP joint OA in terms of the etiology. One is environmental, and the other is genetic.     

Kinematic analysis of mobile-bearing total knee arthroplasty using a 6-DOF knee simulator

Background  The purpose of this study was to investigate the kinematics of the polyethylene insert in two designs of mobilebearing total knee arthroplasty, using a six-degrees-of-freedom knee simulator. It was consequently not clear whether the motion of the polyethylene bearing in mobile-bearing total knee arthroplasty could be demonstrated during the gait cycle or more rapid movement. Methods  A mobile-bearing knee (Zimmer) and a low contact stress rotating-platform design (Depuy) were mounted on a simulator which was regulated by the kinematic data of gait. The simulating test was conducted under a static condition as well as under dynamic conditions of 0.5 Hz and 1.0 Hz. We recorded the motions of the implants with two charge-coupled device (CCD) cameras, and the positions of the insert were calculated. Results  In spite of the same relative motion between the femoral component and the tibial tray, the polyethylene insert showed unique relative motion according to the given condition. The motion of the insert during the dynamic conditions was considerably decreased in comparison to the static condition in both mobile-bearing designs. In addition, the insert showed a smaller amplitude and frequency of rotations under increasing speed in the low contact stress rotating-platform design. The low contact stress rotating-platform design showed a larger amplitude and frequency of rotations than the mobilebearing knee. Conclusions  Despite the mobility of the insert in the mobilebearing total knee arthroplasty, the motion of the insert was decreased during dynamic conditions because of the disruption of full contact between the femoral component and the polyethylene insert. Differences in the rotation between the mobile-bearing knee and the low contact stress rotatingplatform design were due to the fixed axis of the internalexternal rotation in the low contact stress rotating-platform design. The theoretical advantages for the mobile-bearing design over the fixed-bearing design were not demonstrated in this study.     

An immunologic pathway for intravascular catabolism of creatine kinase subform MM3.

In vitro incubation of the MM3 subform of human creatine kinase (ATP:creatine N-phosphotransferase, EC 2.7.3.2, CK) with fresh human serum resulted in the formation of a complex of high relative molecular mass (Mr 320 kDa). The formed complex (macro CK-MM3) consists of both CK-MM3 and immunoglobulin A (IgA), and its amount of the formed complex was proportional to CK-MM3 activity and IgA concentration. Two molecules of CK-MM3 combined with one molecule of IgA, and the immunoglobulin inhibited the enzyme activity. As IgA does not form complexes with other subforms (CK-MM2 and CK-MM1) or CK-MB, the antigen specificity of IgA to CK-MM3 is definitely exacting. The circumstantial evidence suggests that macro CK-MM3 is a specific antigen-antibody complex. Macro CK-MM3 was detected in all of the examined sera of adult patients with more than 2001 U/1 CK activity (the positive percentage of macro CK-MM3 in all adult patients was 73%), but not detected in sera of patients who were younger than 12 months old. No relationship was observed between macro CK-MM3 and the patients' underlying diseases. Macro CK-MM3 formation suggested to be an immunologic pathway for intravascular catabolism of CK-MM3 when its activity increases.     

A pharmacokinetic study in (mature and premature) neonates treated with amikacin through intravenous drip infusion

A pharmacokinetic study was conducted in neonates (mature, premature) to which amikacin (AMK) was administered through intravenous drip infusion. The results of the study are summarized below. 1. Changes in blood concentrations of AMK obtained after intravenous drip infusion over a period of 30 or 60 minutes were comparable to those after intramuscular injection. 2. When AMK was administered to neonates (mature, premature) at a single intravenous (30 or 60 minutes) dose of 6 mg/kg, peak levels of 15.5 to 26.3 micrograms/ml were attained. These values were within the range of 15 to 30 micrograms/ml which are considered to be safe and effective peak levels. 3. In 0 day-neonates, half-lives of blood AMK levels rather long and widely varied (3 to 8 hours) but, in about 7 day-neonates, half-lives were 3 to 4 hours. 4. It is considered from the above results that the safe and effective blood concentrations of AMK in 0 to 7 day-old neonates can be obtained from intravenous administrations at each dose of 6 mg/kg repeated with intervals of 12 or 24 hours and, in 8 days or older neonates, from intravenous drip infusions over 30 or 60 minutes at each dose of 6 mg/kg repeated with intervals of 12 hours. 5. For neonates with very low birth weights, individual doses and intervals should be separately investigated.