Automated Detection, Segmentation, and Tracking of Brain Metastases in Repeated Courses of Stereotactic Radiosurgery Using Integrated Artificial Intelligence

PURPOSE/OBJECTIVE(S)

Salvage stereotactic radiosurgery (SRS) for distant brain metastases has been demonstrated as a safe and effective approach for intracranial recurrences after initial SRS. However, accurate tumor detection and segmentation among responding tumors within the irradiated parenchyma can be challenging. The requirement for the registration and reference to the previous course of SRS is very time-consuming and suffers significant inter and intra-reader variability. Artificial intelligence (AI)-assisted system has been proven to improve the accuracy and efficiency in the clinical flow of de-novo SRS. We hypothesize that an integrated AI system can facilitate an automated tumor contouring process for repeated SRS.

MATERIALS/METHODS

Three patients who underwent their third course of SRS to brain metastases were selected for the pioneering works. They have had two sessions of SRS with a mean lesion number of 4 and 3.7, respectively. VBrain, an FDA-approved brain tumor management AI platform, was used to co-registered serial MR scans and automatically identify, track, and contour brain metastases for each course of SRS. The AI also indicated new lesions and treated lesions for each course. Three radiation oncologists experienced in brain SRS contoured the gross tumor volumes (GTVs) of the third course of SRS in two reader modes (assisted then unassisted) with a memory washout period of one week between each section. The segmentation ground truth was established through consensus among the three experts. Lesion-wise sensitivity, contouring accuracy, and consuming time were compared between the two contouring modes.

RESULTS

In each patient, there were 15, 11, and 9 metastases, with a median diameter of 4.72 (95% CI: 4.05, 6.91) mm. The mean lesion-wise sensitivity was 96.96±2.47% with AI assistance and 76.90 ± 7.10% without assistance. There were two false-positive lesions in the assisted read, resulting in a low average false-positive rate of 0.67 per patient, while no false positive for the unassisted mode. AI assistance improved contouring accuracy. The median Dice similarity coefficient (DSC) was 0.71 (95% CI: 0.55, 0.87) for assisted contouring and 0.65 (95% CI: 0.46, 0.85) for unassisted contouring. We also use average Hausdorff distance (HD) to measure segmentation results. The mean HD was 0.72± 0.13 mm versus 0.73±0.08 mm for the two contouring modes (p = 0.02) Furthermore, the median contouring time per case was significantly shorter with AI assistance than without assistance (20.8 minutes vs. 29.8 minutes; p < 0.001), corresponding to a 43.2% time-saving.

CONCLUSION

Our results suggest that the integration of an AI-based system into repeated brain SRS can significantly improve the accuracy and efficiency of tumor detection and segmentation. This approach has the potential to streamline the treatment planning process for salvage SRS.

[Clinical effects of pedicled omental flap transplantation in repairing secondary rejection wounds after brain pacemaker implantation]

Objective: To explore the clinical effects of pedicled omental flap transplantation in repairing secondary rejection wounds after brain pacemaker implantation. Methods: A retrospective observational study was conducted. From January to August 2021, 5 patients with secondary rejection wounds after brain pacemaker implantation who met the inclusion criteria were admitted to the Wound Repair Center of Ruijin Hospital of Shanghai Jiao Tong University School of Medicine, including 3 males and 2 females, aged 56-69 years, with the wound developed at the pulse generator implantation site in the chest in 2 cases, at the connection site of the wire and electrode behind the ear in 2 cases, and at both the chest and the back of the ear in 1 case. All the wounds were repaired by pedicled omental flap transplantation. The wound area after debridement was 2-15 cm2. After operation, the wound healing and related complications (pain, infection, incisional hernia, omental flap necrosis, etc.) were observed. During follow-up, the recurrence of the wound was observed. Results: The wounds of all 5 patients healed within 2 weeks after operation, without related complications. During follow up of 12-18 months, 1 patient got a recurrence of rejection wound behind the left ear 4 months after surgery and eventually had the brain pacemaker removed; the other 4 patients had no recurrence of wounds. Conclusions: Pedicled omental flap transplantation can repair the secondary rejection wounds after brain pacemaker implantation safely and effectively, with few postoperative complications.

[To master the rules and characteristics of wound repair for wound healing promotion]

Wound repair has its inherent pathophysiological mechanism, presenting a complex network regulation. However, these contents are not detailed exhaustively or systematically in the medical undergraduate education system in China and even the world. Therefore, it is difficult for those clinicians who are not engaged in wound repair related research to fully understand the mechanism of wound repair and its relationship with the clinical process. To provide a reference for clinical work, this article summarizes the sequential, local, time-bounding characteristics of wound healing related to the clinical practice through the understanding of the relevant mechanisms of wound repair.

[Receptor pathways of glycated basic fibroblast growth factor affecting the proliferation and vascularization of human dermal microvascular endothelial cells]

Objective: To investigate the receptor pathways of glycated basic fibroblast growth factor (bFGF) on proliferation and vascularization of human dermal microvascular endothelial cells (HDMECs). Methods: The experimental research method was used. Glycated bFGF stimulating solution was prepared with glucose and bFGF. HDMECs of the third to sixth passages were used in the experiment. Cells were divided into small interfering RNA (siRNA)-positive control group, siRNA-negative control group, siRNA-receptor for advanced glycation end product (RAGE) group, and siRNA-receptor for fibroblast growth factor (FGFR) group and transfected with siRNA-positive control glyceraldehyde-3-phosphate dehydrogenase, siRNA-negative control, siRNA-RAGE, and siRNA-FGFR for 4 to 6 hours, and then were added into HDMEC culture medium for routine culture. The transfection effect of siRNA was identified by reverse transcription polymerase chain reaction. The cells were divided into normal control group, glycated bFGF alone group, siRNA-RAGE alone group, and siRNA-RAGE+ glycated bFGF group, and seeded into 96-well plate and 6-well plate. Cells in siRNA-RAGE alone group and siRNA-RAGE+ glycated bFGF group were transfected with siRNA-RAGE and then were added into HDMEC culture medium for routine culture. After two days, the original HDMEC culture medium was discarded, and cells in siRNA-RAGE alone group were routinely cultured in HDMEC culture medium, cells in siRNA-RAGE+ glycated bFGF group were routinely cultured in glycated bFGF stimulating solution. Cells in normal control group were routinely cultured in HDMEC culture medium, and cells in glycated bFGF alone group were routinely cultured in glycated bFGF stimulating solution. After transfection with siRNA-RAGE, cells were seeded into 48-well plate and divided into siRNA-RAGE alone group and siRNA-RAGE+ glycated bFGF group. Another cells were directly seeded into 48-well plate without transfection and divided into normal control group and glycated bFGF alone group. Cells in the 4 groups were conducted with the corresponding treatment as above. Cells were divided into normal control group, glycated bFGF alone group, siRNA-FGFR alone group, and siRNA-FGFR+ glycated bFGF group and seeded into 96-, 6-, and 48-well plates, respectively, with the corresponding treatment the same as above. Only siRNA-RAGE was replaced by siRNA-FGFR. Cell counting kit 8 method was used to determine the proliferation of cells after 2 days of culture (sample number was 6), flow cytometry was used to detect the apoptosis of cells after 2 days of culture (sample number was 3), tube forming test was used to detect the angiogenesis of cells after 6 hours of culture (sample number was 4). Data were statistically analyzed with one-way analysis of variance and least significant difference t test. Results: At the 200 bp band, there were no target genes in siRNA-positive control group, siRNA-RAGE group, or siRNA-FGFR group, but target genes were detected in siRNA-negative control group, indicating the success of siRNA transfection. After 2 days of culture, the absorbance value of cells in glycated bFGF alone group was significantly lower than that of normal control group (t=2.359, P<0.05); absorbance value of cells in siRNA-RAGE+ glycated bFGF group was significantly higher than that of glycated bFGF alone group (t=3.858, P<0.01), which was similar to that of siRNA-RAGE alone group (t=2.148, P>0.05). The absorbance value of cells in siRNA-FGFR+ glycated bFGF group was similar to that of glycated bFGF alone group (t=0.805, P>0.05), but significantly lower than that of siRNA-FGFR alone group (t=4.201, P<0.01). After 2 days of culture, the apoptotic rate of cells in glycated bFGF alone group was significantly higher than that of normal control group (t=2.416, P<0.05). The apoptotic rate of cells in siRNA-RAGE+ glycated bFGF group was significantly lower than the rates in glycated bFGF alone group and siRNA-RAGE alone group (t=3.861, 2.724, P<0.05 or P<0.01). There were no statistically significant differences in apoptosis rate of cells among normal control group, glycated bFGF alone group, siRNA-FGFR alone group, and siRNA-FGFR+ glycated bFGF group (F=2.218, P>0.05). After 6 hours of culture, the number of tubules of cells in normal control group (636±5) was significantly more than that of glycated bFGF alone group (580±8, t=10.825, P<0.01), and the number of tubules of cells in siRNA-RAGE+ glycated bFGF group (647±10) was significantly more than those of glycated bFGF alone group and siRNA-RAGE alone group (628±4, t=13.040, 3.641, P<0.01). After 6 hours of culture, the number of tubules of cells in siRNA-FGFR+ glycated bFGF group (619±5) was more than that of glycated bFGF alone group (t=9.000, P<0.01), but less than that of siRNA-FGFR alone group (632±3, t=2.814, P<0.05). Conclusions: Glycated bFGF affects the proliferation and angiogenesis of HDMEC through RAGE pathway, which may be one of the reasons for impaired wound healing of diabetic skin.

[Some thoughts on the coordinated development of burn department and wound repair department]

On November 29, 2019, in order to strengthen the management of the diagnosis and treatment of the chronic refractory wounds, the National Health Commission released a notice that requires the qualified medical institutions in China to establish wound repair department. To ease the concern that the establishment of wound repair department could hinder the construction and development of burn discipline, the authors put forward their views based on the necessity of establishing wound repair department, the space for the respective development of burn department and wound repair department, and how to coordinate the development of burn department and wound repair department. It is hoped that this paper would be used as a reference by doctors in both fields of burn care and wound repair.

[Pay attention to the exposure risk of patients with chronic wounds on the way to hospital during coronavirus disease 2019 epidemic prevention and control]

Statistics show that 76.74% (4 688) of 6 109 patients with chronic wounds are over 50 years of age; the proportion of patients with underlying diseases in all age groups above 50 years ranges from 78.25% to 100.00%. Among the underlying diseases of chronic wound patients, the top four diseases are diabetes mellitus, cardiovascular and cerebrovascular diseases, hypertension, and respiratory diseases. The above underlying diseases and ages of patients are the susceptibility factors of coronavirus disease 2019 released by National Health Commission of China. It is an unavoidable fact that the patients with chronic wounds have to go to the hospital for treatment prescribed by the physician. At the same time, we found that quite a few patients preferred going far afield in choosing hospital for treatment due to various reasons. During the prevention and control of coronavirus epidemic, this " go far afield" style of seeking medical treatment may increase the exposure risk during travelling. Accordingly, we convened 36 wound care clinics in different regions in Shanghai to implement the " Five Measures" encouraging the patients with chronic wounds to seek medical treatment nearby. The principle of this operation is that when seeking medical treatment, patients with chronic wounds should try their best to reduce the travel distance as much as possible to minimize the exposure risk during the epidemic period, which will in turn support the campaign of epidemic prevention and control.

[Preliminary evaluation and mechanism of adipose-derived stem cell transplantation from allogenic diabetic rats in the treatment of diabetic rat wounds]

Objective: To investigate whether adipose-derived stem cells (ASCs) from allogeneic diabetic rats can promote wound healing in diabetic rats or not and the mechanism. Methods: (1) Fifty-six male Wistar rats aged 12-16 weeks were divided into diabetic group and healthy group according to the random number table (the same grouping method below), with 28 rats in each group. Rats in healthy group were not treated with any treatment. Rats in diabetic group were injected with 10 g/L streptozotocin 60 mg/kg intraperitoneally in one time to establish the diabetic model. Four rats in diabetic group and 4 rats in healthy group were selected according to the random number table, and the adipose tissue in the inguinal region was taken to culture and purify ASCs, so as to obtain healthy rat-derived ASCs (hereinafter referred to as nASCs) and diabetic rat-derived ASCs (hereinafter referred to as dASCs). The third passage of nASCs (n=3) and dASCs (n=3) were taken, and the positive expression rates of cell surface differentiation antigens CD105, CD31, CD34, and CD44 were detected with flow cytometer for defining ASCs purity. (2) The rest 24 rats in healthy group and 24 rats in diabetic group were used to make three round full-thickness skin defect wounds with a diameter of 12 mm on the back of each rat. Immediately after injury, phosphate buffer saline (PBS), nASCs of 2×10(7)/mL, and dASCs of 2×10(7)/mL each in the volume of 0.5 mL were subcutaneously injected into three wounds and their margins of each rat, respectively. On post injury day (PID) 1, 3, 7, and 12, 6 rats in each group were selected according to the random number table to calculate the wound area, and the wound tissue was stained with hematoxylin-eosin to observe the histological morphology of the wound. (3) Human ASCs (hASCs) were subcultured, and the 4th to 7th passage of cells were used for the subsequent experiments. The hASCs were divided into 7 groups, with 12 samples in each group. Cells in blank control group were cultured with mesenchymal stem cell culture medium, and cells in simple advanced glycation end products (AGEs) group, simple protein group, simple high glucose group, simple high osmotic pressure group, AGEs-high glucose combination group, and protein-high osmotic pressure combination group were cultured with mesenchymal stem cell culture medium containing a final mass concentration of 100 mg/L AGEs, 100 mg/L bovine serum albumin (BSA), 28 mmol/L D-glucose, 28 mmol/L mannitol, 100 mg/L AGEs+ 28 mmol/L D-glucose, 100 mg/L BSA+ 28 mmol/L mannitol, respectively. Cell proliferation was detected by cell counting kit 8 at post culture hour (PCH) 2 and on post culture day (PCD) 2, 4 and 6. (4) The hASCs were divided into blank control group, simple AGE group, simple high glucose group, and AGE-high glucose combination group, with 12 samples in each group, which were treated the same as corresponding groups in experiment (3). On PCD 0, 2, 4, and 6, the positive expression rates of cell surface differentiation antigens CD105, CD44, and CD45 were detected by flow cytometer to estimate their homeostasis. (5) The hASCs were divided into AGE-high glucose combination group and protein-high osmotic pressure combination group, with 9 samples in each group, which were treated the same as corresponding groups in experiment (3). On PCD 2, 4, and 6, the expression of intracellular protein was detected by cyanine 3-streptavidin double-antibody sandwich technique. Data were processed with analysis of variance for factorial design, least significant difference test, and Bonferroni correction. Results: (1) The positive expression rates of CD44 in nASCs and dASCs were both higher than 96%, the positive expression rates of CD31 and CD34 were low, and the positive expression rates of CD105 were about 40%, which basically met the purity requirements. (2) The areas of wounds treated by three methods in rats of healthy group and diabetic group were similar on PID 1 (P>0.05). In healthy group, compared with (0.682 1±0.078 9), (0.314 3±0.113 7), and (0.064 3±0.002 1) cm(2) of the PBS-treated wounds in rats, the area of nASCs-treated wounds in rats decreased significantly on PID 3, 7, and 12 [(0.464 1±0.092 6), (0.223 9±0.072 7), and (0.034 3±0.012 5) cm(2), P<0.05], the area of dASCs-treated wounds in rats decreased significantly on PID 3 and 12 [(0.514 1±0.124 1) and (0.043 7±0.032 8) cm(2), P<0.05] but was not obviously changed on PID 7 [(0.274 2±0.062 5) cm(2), P>0.05]. Compared with those of the dASCs-treated wounds of rats within the same group, the area of the nASCs-treated wounds of rats in healthy group decreased significantly on PID 3 and 7 (P<0.05) but was not obviously changed on PID 12 (P>0.05). In diabetic group, compared with (0.853 5±0.204 8), (0.670 5±0.164 8), and (0.131 4±0.074 4) cm(2) of the PBS-treated wounds in rats, the area of nASCs-treated wounds in rats decreased significantly on PID 3, 7, and 12 [(0.633 4±0.132 5), (0.331 8±0.023 5), and (0.074 2±0.003 8) cm(2), P<0.05], the area of dASCs-treated wounds in rats decreased significantly on PID 3 [(0.773 6±0.182 2) cm(2), P<0.05] but was not obviously changed on PID 7 and 12 [(0.510 6±0.192 2) and (0.114 4±0.003 1) cm(2), P>0.05]. Compared with the dASCs-treated wounds of rats within the same group, the area of the nASCs-treated wounds of rats in diabetic group was not obviously changed on PID 3 and 7 (P>0.05) but decreased significantly on PID 12 (P<0.05). There was no obvious difference in histological morphology of the wounds treated with three methods in rats of each group on PID 1. On PID 3, a small amount of microvessels were formed in the wounds treated with nASCs and dASCs of rats in both groups, but microvessel formation was almost undetected in the PBS-treated wounds. On PID 7, more small blood vessels and fibroblasts (Fbs) were observed in the wounds treated with nASCs and dASCs of rats in both groups, but the small blood vessels and Fbs were slightly less in the PBS-treated wounds. On PID 12, the wounds treated with nASCs and dASCs of rats in the two groups were covered by epithelial tissue, the granulation tissue in the PBS-treated wounds of rats in healthy group was not obvious, and the PBS-treated wounds of rats in diabetic group were not completely epithelialized. (3) Compared with those of blank control group, the cell number of hASCs in simple AGEs group decreased significantly on PCD 2, 4, and 6 (P<0.05), which increased significantly on PCD 2 and 4 in simple high glucose group (P<0.05), and that in AGEs-high glucose combination group decreased significantly on PCD 4 and 6 (P<0.05). (4) Compared with that on PCD 4 within the same group, the positive expression rate of CD105 in hASCs decreased significantly in blank control group, simple AGEs group, and AGEs-high glucose combination group on PCD 6 (P<0.05). The positive expression rate of CD44 was higher than 95%, and that of CD45 was less than 2% in hASCs of each group at each time point. (5) Detection values of 7 proteins were located in the confidence interval. The expression levels of basic fibroblast growth factor and tissue inhibitor of metalloproteinase-1 in hASCs of AGEs-high glucose combination group and protein-high osmotic pressure combination group showed increasing trend with the prolongation of culture time. The expression level of human monocyte chemoattractant protein 1 (MCP-1) in hASCs of AGEs-high glucose combination group showed increasing trend with the prolongation of culture time, while the expression level of growth-regulated oncogene (GRO) on PCD 6 was significantly higher than that on PCD 4 within the same group (P<0.05); the expression levels of MCP-1 and GRO in hASCs of protein-high osmotic pressure combination group showed decreasing trend with the prolongation of culture time. The expression level of follistatin in hASCs of protein-high osmotic pressure combination group decreased obviously on PCD 4, while that in hASCs of AGEs-high glucose combination group was significantly lower on PCD 6 than that on PCD 4 (P<0.05). The expression level of vascular endothelial growth factor (VEGF) in hASCs of protein-high osmotic pressure combination group decreased gradually with the prolongation of culture time, while that in hASCs of AGEs-high glucose combination group on PCD 4 decreased significantly as compared with that on PCD 2 (P<0.05). The expression level of urokinase-type plasminogen activator receptor in hASCs of protein-high osmotic pressure combination group on PCD 6 was significantly higher than that on PCD 4 within the same group (P<0.05) and that of AGEs-high glucose combination group on PCD 6 (P<0.05). Conclusions: Both nASCs and dASCs can promote wound healing in rats with simple defect injury, but dASCs have no significant effect on wound healing in rats with diabetes mellitus, which may be related to the inhibition of ASCs proliferation and the influence of high glucose and AGEs intervention on their homeostasis and secretory function.

[Thoughts and principles of diagnosis and treatment of chronic refractory wounds in China]

The correct thoughts and principles of diagnosis and treatment of chronic refractory wounds need to be formulated. Through the relevant domestic and international consensus and based on clinical experience, the Thoughts and principles of diagnosis and treatment of chronic refractory wounds in China is proposed. It is considered that in the diagnosis and treatment of chronic refractory wounds, in the case of fully understanding the patient's medical history, the following thoughts and principles should be complied in order. (1) Pay attention to the cleanliness of the wound after being cleaned. (2) Reasonably perform debridement to avoid being " excessive" or " not thorough". (3) Reasonably perform examination, diagnosis, and differential diagnosis of pathogenic factors. (4) Treat according to etiology. (5) Find comorbidities and prevent adverse outcomes. (6) Select the correct wound treatment method reasonably and timely. When the conservative wound care treatment is considered, pay attention to embodying the concept of etiological treatment, treat the wound according to the principles of safety, phase, selectivity, and effectiveness, and make a reasonable choice of continuing conservative treatment or surgical treatment in time after completing the preparation of the wound bed. When surgical treatment is considered, pay attention to the selection of reasonable surgical method and donor site, pay attention to the healing rate of surgical wound site and the outcome of donor site, and give reasonable protection to the wound site after surgery. (7) Carry out rehabilitation treatment after wound healing and related health education.

[Application value of endoscope in probing chronic wound with sinus tract in clinic]

Objective: To explore the application value of endoscope in probing the chronic wound with sinus tract in clinic. Methods: Twenty-eight chronic wounds with sinus tracts from 27 patients conforming to the inclusion criteria admitted to Outpatient Department of Wound Healing Center of Ruijin Hospital from December 2017 to March 2018 were investigated in a prospective and self-controlled trial. After being cleaned, the diameter of the opening of sinus tract was measured with a rule. A probe was used to measure the depth of a sinus tract according to the touch from the probe extremity in operation, and to measure the depth of a sinus tract that could be observed with naked eyes with the help of a pair of hemostatic forceps. Five minutes later, a probe was inserted deeply into the sinus tract to measure the depth under the endoscopic view combined with touch from the probe extremity in operation. Afterwards, the sinus tract was observed with endoscope, and the depth of the tract which could be observed under the endoscopic view was measured using a probe inserted deeply into the sinus tract. After completion of the above exploration, the sinus tract was infused with contrast agent Omnipaque 350 and scanned by computed tomography (CT) later to obtain its depth. The following indicators were calculated: the ratio of the depth of the sinus tract measured by CT to the diameter of the opening of the sinus tract (hereinafter referred to as the depth/diameter ratio of the sinus tract), the deviation rate comparing the depth of the sinus tract measured by conventional method (measured by probe only) and by endoscope (measured by probe under the endoscope view) with the depth of the sinus tract measured by CT (hereinafter referred to as the deviation rate of the measured depth of the sinus tract), the deviation rate comparing the depth of the sinus tract that could be observed measured by conventional method and by endoscope with the depth of the sinus tract measured by CT (hereinafter referred to as the deviation rate of the depth of the sinus tract that could be observed). Data were processed with paired t test. Pearson correlation analysis was applied to analyze the correlation between the depth/diameter ratio of the sinus tract and the deviation rate of the measured depth of the sinus tract and the deviation rate of the depth of the sinus tract that could be observed by conventional method and by endoscope. Results: The depth/diameter ratio of the sinus tract of this group of wounds was 1-32 (8±7). The deviation rate of the measured depth of the sinus tract and the deviation rate of the depth of the sinus tract that could be observed by conventional method were (19±14)% and (79±18)%, respectively, both obviously larger than (9±9)% and (25±25)% by endoscope (t=3.837, 13.626, P<0.01). Positive correlation existed between the depth/diameter ratio of the sinus tract and the deviation rate of the measured depth of the sinus tract by conventional method, and between the depth/diameter ratio of the sinus tract and the deviation rate of the depth of the sinus tract that could be observed by conventional method and by endoscope (r=0.514, 0.585, 0.651, P<0.01). However, there was no obvious correlation between the depth/diameter ratio of the sinus tract and the deviation rate of the measured depth of the sinus tract by endoscope (r=0.113, P>0.05). Conclusions: Compared with the conventional method, application of endoscope is able to get more accurate data of chronic wounds with sinus tracts and observe the wounds with wider range.

[Effects of denatured collagen type Ⅰ on differentiation of human fibroblasts into myofibroblasts]

Objective: To investigate the effects of denatured collagen type Ⅰ on differentiation of human fibroblasts into myofibroblasts. Methods: A small amount of normal skin donated by burn patients undergoing scar surgery was collected. Human fibroblasts were obtained by method of explant culture and then sub-cultured. The fourth passage of cells were used in the following experiments. (1) Fibroblasts were divided into normal collagen group and denatured collagen group according to the random number table, with 10 wells in each group. Fibroblasts in normal collagen group were cultured on normal collagen type Ⅰ coated coverslips. Fibroblasts in denatured collagen group were cultured on denatured type Ⅰ collagen coated coverslips. Expression of proliferating cell nuclear antigen (PCNA) was detected by immunohistochemical method, and the percentage of PCNA positive cells was calculated. (2) Another batch of fibroblasts were grouped and treated as in (1), with 12 wells in each group. Proliferation activity of cells was determined with methyl-thiazolyl-tetrazolium colorimetry method. (3) Another batch of fibroblasts were grouped and treated as in (1), and the microfilament morphology of cells was observed by rhodamine-phalloidin staining. (4) Another batch of fibroblasts were grouped and treated as in (1). Expression of α smooth muscle actin (α-SMA) of cells was detected by immunohistochemical method, and expression of OB-cadherin of cells was detected by immunofluorescence method. (5) Another batch of fibroblasts were divided into normal collagen, denatured collagen, and common coverslips groups according to the random number table, with 6 wells in each group. Fibroblasts in normal collagen and denatured collagen groups were treated as in (1), while fibroblasts in common coverslips group were cultured on coverslips without collagen coating. Expressions of α-SMA and OB-cadherin of cells were determined with Western blotting. (6) Another batch of fibroblasts were grouped and treated as in (5), and then the mRNA expressions of collagen type Ⅰ, collagen type Ⅲ, and α-SMA of cells were determined with real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were processed with t test, one way analysis of variance, and least-significant difference test. Results: (1) The percentage of PCNA positive cells in denatured collagen group was (83±9)%, significantly higher than (29±9)% in normal collagen group (t=13.53, P<0.01). (2) The proliferation activity of fibroblasts in denatured collagen group was 0.32±0.06, significantly higher than 0.25±0.05 in normal collagen group (t=3.06, P<0.01). (3) The microfilament of fibroblasts in normal collagen group was arranged vertically and in parallel way, paralleling the long axis of cells. The microfilament of fibroblasts in denatured collagen group was denser and thicker. (4) Most fibroblasts in normal collagen group showed long shuttle-like shape typically. Morphology of fibroblasts in denatured collagen group changed, and cells were obviously spreading. Expressions of α-SMA and OB-cadherin of fibroblasts in denatured collagen group were stronger than those in normal collagen group. (5) Expressions of α-SMA of fibroblasts in denatured collagen, normal collagen, and common coverslips groups were respectively 1.69±0.41, 0.89±0.27, and 1.46±0.42. Expression of α-SMA of fibroblasts in denatured collagen group was significantly higher than that in normal collagen group (P<0.01). Expressions of OB-cadherin of fibroblasts in denatured collagen, normal collagen, and common coverslips groups were respectively 5.17±0.28, 2.21±0.10, and 4.01±0.56. Expression of OB-cadherin of fibroblasts in denatured group was significantly higher than that in normal collagen group (P<0.01). (6) There was no significant difference in mRNA expression of collagen type Ⅰ of fibroblasts in denatured collagen, normal collagen, and common coverslips groups (F=2.71, P>0.05). The mRNA expressions of collagen type Ⅲ and α-SMA of fibroblasts in normal collagen group were significantly lower than those in denatured collagen group (P<0.01). Conclusions: Denatured collagen type Ⅰ may influence the activity of fibroblasts, thus inducing fibroblasts differentiating into myofibroblasts.

[Treatment of patients with refractory wounds]

Experienced over twenty years of theoretical accumulation and ten years of clinical exploration, wound repair speciality in our country is in the phase of enhancing comprehensive ability. Our wound healing experts team has successfully carried out treatment of suspected bacterial weapon related chronic wounds, which lasted up to more than 70 years, through multilateral cooperation. We summarized the surgical program of wound fibrous tissue removal and scalp as donor sites for long-term non-healing wounds in the elderly. At the same time, we explored the operating mode of internet-based technology to extend diagnosis and treatment of chronic wounds in remote areas, which was with efficiency and convenience.

Transition of radiative recombination channels from delocalized states to localized states in a GaInP alloy with partial atomic ordering: a direct optical signature of Mott transition?

Anderson localization is a predominant phenomenon in condensed matter and materials physics. In fact, localized and delocalized states often co-exist in one material. They are separated by a boundary called the mobility edge. Mott transition may take place between these two regimes. However, it is widely recognized that an apparent demonstration of Anderson localization or Mott transition is a challenging task. In this article, we present a direct optical observation of a transition of radiative recombination dominant channels from delocalized (i.e., local extended) states to Anderson localized states in the GaInP base layer of a GaInP/GaAs single junction solar cell by the means of the variable-temperature electroluminescence (EL) technique. It is found that by increasing temperature, we can boost a remarkable transition of radiative recombination dominant channels from the delocalized states to the localized states. The delocalized states are induced by the local atomic ordering domains (InP/GaP monolayer superlattices) while the localized states are caused by random distribution of indium (gallium) content. The efficient transfer and thermal redistribution of carriers between the two kinds of electronic states was revealed to result in both a distinct EL mechanism transition and an electrical resistance evolution with temperature. Our study gives rise to a self-consistent precise picture for carrier localization and transfer in a GaInP alloy, which is an extremely technologically important energy material for fabricating high-efficiency photovoltaic devices.

Anisotropy and Corotation of Galactic Cosmic Rays

The intensity of Galactic cosmic rays is nearly isotropic because of the influence of magnetic fields in the Milky Way. Here, we present two-dimensional high-precision anisotropy measurement for energies from a few to several hundred teraelectronvolts (TeV), using the large data sample of the Tibet Air Shower Arrays. Besides revealing finer details of the known anisotropies, a new component of Galactic cosmic ray anisotropy in sidereal time is uncovered around the Cygnus region direction. For cosmic-ray energies up to a few hundred TeV, all components of anisotropies fade away, showing a corotation of Galactic cosmic rays with the local Galactic magnetic environment. These results have broad implications for a comprehensive understanding of cosmic rays, supernovae, magnetic fields, and heliospheric and Galactic dynamic environments.

Observation by an air-shower array in Tibet of the multi-TeV cosmic-ray anisotropy due to terrestrial orbital motion around the Sun

We report on the solar diurnal variation of the galactic cosmic-ray intensity observed by the Tibet III air shower array during the period from 1999 to 2003. In the higher-energy event samples (12 and 6.2 TeV), the variations are fairly consistent with the Compton-Getting anisotropy due to the terrestrial orbital motion around the Sun, while the variation in the lower-energy event sample (4.0 TeV) is inconsistent with this anisotropy. This suggests an additional anisotropy superposed at the multi-TeV energies, e.g., the solar modulation effect. This is the highest-precision measurement of the Compton-Getting anisotropy ever made.

In situ RT-PCR detection of hepatitis C virus genotypes in Chinese patients with hepatocellular carcinoma

The correlation of hepatitis C virus genotypes and the development of hepatocellular carcinoma is still controversial. The most pertinent studies are conducted by seroepidemiological methods. It has been suggested that tissue RT-PCR may be more efficient than serological testing for hepatitis C virus RNA. The purpose of this study was to investigate the infectious status of hepatitis C virus genotypes in hepatocellular carcinoma tissue for revealing the role of hepatitis C virus genotypes in carcinogenesis of hepatocellular carcinoma. Hepatitis C virus genotypes in cancerous and noncancerous liver tissues of 95 Chinese patients with hepatocellular carcinoma were analyzed by a modified type-specific in situ reverse transcription polymerase chain reaction (RT-PCR) method. Hepatitis C virus genotypes were simultaneously examined by Okamoto's method using extracts from hepatocellular carcinoma tissues. The hepatitis C virus genotypes in hepatocellular carcinoma tissues were found including 1b, 2a, mixed type (1b+2a) and 3a in 13, 23, 2 and 4 samples respectively. There was no significant difference in either the positivities between 1b (13.7%, 13/95) and 2a (24.2%, 23/95) (P>0.05) or the staining intensity and distribution of positive cells between 1b and 2a (p>0.05). No statistically significant difference was found between the two virus genotypes in main clinico-pathologic parameters of hepatocellular carcinoma. The localizations of hepatitis C virus RNA-positive signals were mainly cytoplasmic (22/36) in noncancerous regions, but nucleocytoplasmic (19/36) or nuclear (3/36) in cancerous regions. The positive nucleocytoplasmic/nuclear signals of genotype 1b (11/13) in hepatocellular carcinoma were seen more frequently than those of genotype 2a (11/23) (P<0.05). The discordant hepatitis C virus 2a and 1b positivities in serum samples and in cancerous tissues of hepatocellular carcinoma patients were also found, suggesting that the detection of serum hepatitis C virus genotypes in the patients with hepatocellular carcinoma may not reflect the actual status of hepatitis C virus genotypes in cancerous tissue. The pathogenetic significance of existence of hepatitis C virus gene in the nucleus of hepatocytes and malignant cells needs further investigation.

Characterization of two isomeric beta-d-glucosiduronic acids derived from 1,2-diethyl-3-hydroxypyridin-4-one (CP94) in rat liver homogenate incubates

1,2-Diethyl-3-hydroxypyridin-4-one (CP94) is an orally active iron chelator with potential for use in photodynamictherapy. This investigation reports the formation and characterization of two isomeric glucuronides of CP94 in rat liver homogenate incubates. To assign the glucuronidation sites in the CP94 molecule, two O-methylated derivatives of CP94 have been synthesized. By comparing the spectral characteristics of the CP94 3-O- and 4-O-methyl derivatives with CP94 and the CP94 glucuronides formed during incubation, evidence was obtained which enabled the assignment of these two isomeric glucuronides to the 3-O-glucuronide and 4-O-glucuronide of CP94. It was found that the 3-O-glucuronide was the dominant CP94 metabolite under in-vitro conditions. In an attempt to understand the potential influence of structural variation on the glucuronidation of CP94 analogues, the 1-and 2-monoethyl derivatives of CP94 were investigated. The 2-monoethyl derivative of CP94 yielded only the 3-O-glucuronide in rat liver homogenate incubate, while no glucuronide was formed from the 1-monoethyl derivative. In addition, no glucuronide from the 3-O-methyl or 4-O-methyl derivatives of CP94 could be detected. The relevance of these findings to the development of new 3-hydroxypyridin-4-one iron chelators is discussed.

Atm knock-in mice harboring an in-frame deletion corresponding to the human ATM 7636del9 common mutation exhibit a variant phenotype

ATM, the gene mutated in the human immunodeficiency disorder ataxia-telangiectasia (A-T), plays a central role in recognizing ionizing radiation damage in DNA and in controlling several cell cycle checkpoints. We describe here a murine model in which a nine-nucleotide in-frame deletion has been introduced into the Atm gene by homologous recombination followed by removal of the selectable marker cassette by Cre-loxP site-specific, recombination-mediated excision. This mouse, Atm-DeltaSRI, was designed as a model of one of the most common deletion mutations (7636del9) found in A-T patients. The murine Atm deletion results in the loss of three amino acid residues (SRI; 2556-2558) but produces near full-length detectable Atm protein that lacks protein kinase activity. Radiosensitivity was observed in Atm-DeltaSRI mice, whereas the immunological profile of these mice showed greater heterogeneity of T-cell subsets than observed in Atm(-/-) mice. The life span of Atm-DeltaSRI mice was significantly longer than that of Atm(-/-) mice when maintained under nonspecific pathogen-free conditions. This can be accounted for by a lower incidence of thymic lymphomas in Atm-DeltaSRI mice up to 40 weeks, after which time the animals died of other causes. The thymic lymphomas in Atm-DeltaSRI mice were characterized by extensive apoptosis, which appears to be attributable to an increased number of cells expressing Fas ligand. A variety of other tumors including B-cell lymphomas, sarcomas, and carcinomas not seen in Atm(-/-) mice were observed in older Atm-DeltaSRI animals. Thus, expression of mutant protein in Atm-DeltaSRI knock-in mice gives rise to a discernibly different phenotype to Atm(-/-) mice, which may account for the heterogeneity seen in A-T patients with different mutations.

Synthesis of 2-amido-3-hydroxypyridin-4(1H)-ones: novel iron chelators with enhanced pFe3+ values

The synthesis of a range of 2-amido-3-hydroxypyridin-4-ones as bidentate iron(III) chelators with potential for oral administration is described. The pKa values of the ligands together with the stability constants of their iron(III) complexes have been determined. Results indicate that the introduction of an amido substituent at the 2-position leads to an appreciable enhancement of the pFe3+ values. The ability of these novel 3-hydroxypyridin-4-ones to facilitate the iron excretion in bile was investigated using a 59Fe-ferritin loaded rat model. The optimal effect was observed with the N-methyl amido derivative 15b, which has an associated pFe3+ value of 21.7, more than two orders of magnitude higher than that of deferiprone (1,2-dimethyl-3-hydroxypyridin-4-one) 1a (pFe3+ = 19.4). Dose response studies suggest that chelators with high pFe3+ values scavenge iron more effectively at lower doses when compared with simple dialkyl substituted hydroxypyridinones.

The COMT L allele modifies the association between MAOB polymorphism and PD in Taiwanese

OBJECTIVE

Reports suggest that catechol-O-methyltransferase (COMT(L/L)) (Val(158)/Met) and monoamine oxidase B (MAOB) intron 13 genotype polymorphism is associated with PD. To understand the ethnicity-specific effects of genetic polymorphism, we performed a case-control study of the association between PD susceptibility and polymorphism of MAOB and COMT, both separately and in combination, in Taiwanese.

METHODS

Two hundred twenty-four patients with PD and 197 controls, matched for age, sex, and birthplace, were recruited. MAOB and COMT polymorphism genotyping was performed by using PCR-based restriction fragment length polymorphism (RFLP) analyses. chi(2), OR, and Fisher's exact tests were used to compare differences in allelic frequencies and genotypes.

RESULTS

The MAOB G genotype (G in men and G:/G in women) was associated with a 2.07-fold increased relative risk of PD. COMT polymorphism, considered alone, showed no correlation with PD risk; however, a significant synergistic enhancement was found in PD patients harboring both the COMT(L) and MAOB G genotypes.

CONCLUSIONS

These results suggest that, in Taiwanese, PD risk is associated with MAOB G intron 13 polymorphism, and this association is augmented in the presence of the COMT(L) genotype, indicating an interaction of these two dopamine-metabolizing enzymes in the pathogenesis of sporadic PD. However, the relatively low frequencies of these combined genotypes in our study necessitates confirmation with a larger sample size.

Biliary and urinary metabolic profiles of 1,2-diethyl-3-hydroxypyridin-4-one (CP94) in the rat

This study compares the biliary and urinary metabolic profiles of 1,2-diethyl-3-hydroxypyridin-4-one (CP94), an orally active iron chelator, in the normal rat. Surprisingly, CP94 was found to form two phase II metabolites, the 3-O- and 4-O-glucuronides. These glucuronides accounted for 38 and 28% of the administered CP94 dose, in bile and urine, respectively. Unchanged CP94 accounted for 5% of the CP94 dose in both bile and urine. The 2-(1'-hydroxy) metabolite of CP94 was found to be the dominant metabolite in urine. In addition, an unstable metabolite was detected in the bile although its structure remains unknown at the present stage. The excretion of iron in bile, after administration of CP94, was found to parallel the biliary elimination of CP94 together with its hydroxylated derivatives, indicating the importance of metabolites in iron excretion.

Hydrolytic and metabolic characteristics of the esters of 1-(3'-hydroxypropyl)-2-methyl-3-hydroxypyridin-4-one (CP41), potentially useful iron chelators

1-(3'-Hydroxypropyl)-2-methyl-3-hydroxypyridin-4-one (CP41) has been extensively investigated as an orally effective iron chelator. In order to improve the pharmacokinetic and metabolic properties of CP41, eleven aromatic esters have been synthesised and tested as potential prodrugs. In the present study, the hydrolytic rates of these CP41 esters in phosphate buffer (pH2.0 and pH 7.4), rat blood and rat liver homogenate have been determined and found to cover a wide range. Generally, they possessed relatively slow hydrolytic rates in phosphate buffer (0-50 nmol/ml/hr at pH 2.0 and 0-140 nmol/ml/hr at pH 7.4). The hydrolytic rates in rat blood fell in the range of 9-5766 nmol/ml blood/hr and in rat liver homogenate 1-800 micromol/g liver tissue/hr. All esters possess a higher lipophilicity than that of the parent compound CP41. Although no apparent relationship was observed between the lipophilicities and hydrolytic rates, the esters with relatively higher hydrolytic rates in liver homogenate tend to possess higher iron scavenging efficacies. Further investigation of the metabolism of selected CP41 esters indicates that metabolism is a key factor influencing the efficacy of CP41 esters, as some esters can be metabolically inactivated in the liver in preference to undergoing ester hydrolysis. Ester design, combined with a knowledge of the prodrug metabolism, is a useful strategy for the production of 3-hydroxypyridin-4-ones with enhanced iron scavenging efficacy.

Design, synthesis, and biological evaluation of aromatic ester prodrugs of 1-(3'-hydroxypropyl)-2-methyl-3-hydroxypyridin-4-one (CP41) as orally active iron chelators

In order to improve chelation efficacy and to minimise toxicity, eleven aromatic ester prodrugs of 1-(3'-hydroxypropyl)-2-methyl-3-hydroxypyridin-4-one (CP41) have been synthesised. The distribution coefficients of these ester prodrugs between 1-octanol and MOPS buffer pH 7.4 were measured together with their rates of hydrolysis at pH 2 and pH 7.4, in rat blood and liver homogenate. The biliary metabolic profiles of selected ester prodrugs were investigated in rats. The in vivo iron mobilisation efficacy of these ester prodrugs has been compared with that of the parent drug using a 59Fe-ferritin loaded rat model. The hydrolytic rates of these esters vary appreciably, esters with heteroaromatic acid moieties being less stable than the corresponding benzoyl analogues. Many prodrugs were found to enhance the ability of the parent hydroxypyridinone to facilitate 59Fe excretion, the optimal effect being observed with the 4-methylbenzoyl ester derivative 8d. However, not all prodrugs provide an increased efficacy, indicating that lipophilicity is not the only factor which influences drug efficacy. Furthermore no clear correlation between lipophilicity, susceptibility towards hydrolysis and efficacy was detected.

Design, synthesis and evaluation of N-basic substituted 3-hydroxypyridin-4-ones: orally active iron chelators with lysosomotrophic potential

To investigate the possibility of targeting chelators into the lysosomal iron pool, nine bidentate 3-hydroxypyridin-4-ones with basic chains have been synthesized. As the turnover of ferritin iron is centred in the lysosome, such strategy is predicted to increase chelator efficacy of bidentate ligands. The pKa values of the ligands together with their distribution coefficients between 1-octanol and 4-morpholinepropane sulphonic acid (MOPS) buffer pH 7.4 have been determined. The in-vivo iron mobilization efficacy of these basic 3-hydroxypyridin-4-ones has been investigated in a 59Fe-ferritin-loaded rat model. No obvious correlation was observed between efficacy and the pKa value of the side chain, although those with pKa > 7.0 tended to be more efficient than those with pKa < 7.0. The imidazole-containing molecules are much less effective than the tertiary amine derivatives. A dose-response study suggested that basic pyridinones are relatively more effective at lower doses when compared with N-alkyl hydroxypyridinones. Optimal effects were observed with the piperidine derivatives 4h and 4i. The derivative 4i at a dose of 150 micromol kg(-1) was more effective than 450 micromol kg(-1) deferiprone, the widely adopted clinical dose.

Liquid extraction and ion-pair HPLC for determination of hydrophilic 3-hydroxypyridin-4-one iron chelators

Hydrophilic 3-hydroxypyridin-4-ones (HPOs), such as 1-(2'-carboxyethyl)-2-methyl-3-hydroxypyridin-4-one (CP38), 1-(3'-hydroxypropyl)-2-methyl-3-hydroxypyridin-4-one (CP41) and 1-(2'-hydroxyethyl)-2-ethyl-3-hydroxypyridin-4-one (CP102), are orally active iron chelators and ester prodrugs of these molecules are currently under investigation. A liquid extraction method using acetonitrile and 2-propanol (80:20 v/v) under acidic and NaCl-saturated conditions has been developed in order to efficiently extract these HPOs from various matrices. The extracted HPOs were determined using a reversed phase polymer HPLC column (PLRP-S 100 A) and the gradient ion-pair mobile phase containing tetrabutylammonium chloride (5 mM) and EDTA (0.5 mM). The extraction recovery of these chelators in phosphate buffer, rat blood and liver homogenate varied from 85 to 94%. The coefficients of variation (C.V.) for within-day determination were in the range of 1.4-3.3% at 1 mM and 2.0-4.7% at 0.1 mM. High accuracy of determination was also achieved.

Synthesis, physicochemical characterization, and biological evaluation of 2-(1'-hydroxyalkyl)-3-hydroxypyridin-4-ones: novel iron chelators with enhanced pFe(3+) values

The synthesis of a range of 2-(1'-hydroxyalkyl)-3-hydroxypyridin-4-ones as bidentate iron(III) chelators with potential for oral administration is described. The pK(a) values of the ligands and the stability constants of their iron(III) complexes have been determined. Results indicate that the introduction of a 1'-hydroxyalkyl group at the 2-position leads to a significant improvement in the pFe(3+) values. Such an effect was found to be greater with the hydroxyethyl substituent than with the hydroxymethyl substituent, particularly in the cases of 1-ethyl-2-(1'-hydroxyethyl)-3-hydroxypyridin-4-one (pFe(3+) = 21.4) and 1,6-dimethyl-2-(1'-hydroxyethyl)-3-hydroxypyridin-4-one (pFe(3+) = 21.5) where an enhancement on pFe(3+) values in the region of two orders of magnitude is observed, as compared with Deferiprone (1, 2-dimethyl-3-hydroxypyridin-4-one) (pFe(3+) = 19.4). The ability of these novel 3-hydroxypyridin-4-ones to facilitate the iron excretion in bile was investigated using a [(59)Fe]ferritin-loaded rat model. Chelators and prodrug chelators possessing high pFe(3+) values show great promise in their ability to remove iron under in vivo conditions.

Observation of Multi-TeV Gamma Rays from the Crab Nebula using the Tibet Air Shower Array

The Tibet experiment, operating at Yangbajing (4300 m above sea level), is the lowest energy air shower array, and the new high-density array constructed in 1996 is sensitive to gamma-ray air showers at energies as low as 3 TeV. With this new array, the Crab Nebula was observed in multi-TeV gamma-rays and a signal was detected at the 5.5 sigma level. We also obtained the energy spectrum of gamma-rays in the energy region above 3 TeV which partially overlaps those observed with imaging atmospheric Cerenkov telescopes. The Crab spectrum observed in this energy region can be represented by the power-law fit dJ&parl0;E&parr0;&solm0;dE=&parl0;4.61+/-0.90&parr0;x10-12&parl0;E&solm0;3 TeV&parr0;-2.62+/-0.17 cm-2 s-1 TeV-1. This is the first observation of gamma-ray signals from point sources with a conventional air shower array using scintillation detectors.

Predominant germ-line mutation of the hMSH2 gene in Japanese hereditary non-polyposis colorectal cancer kindreds

By means of PCR-SSCP and direct sequencing, we detected 12 germ-line mutations of hMSH2 or hMLH1 in 37 Japanese hereditary non-polyposis colorectal cancer (HNPCC) kindreds, of whom 15 satisfied the Amsterdam and 22 the Japanese criteria. The germ-line mutation detection rate of hMSH2 was much higher than that of hMLH1 (11/37 vs. 1/37). The total mutation detection rate of hMSH2 and hMLH1 in the Amsterdam criteria group was significantly higher than that in the Japanese criteria group (9/15 vs. 3/22). Furthermore, the mean age of the HNPCC patients in the mutation-positive group was lower than that in the mutation-negative one; the rates of both vertical transmission and multiplicity of tumors in the mutation-positive group were higher than those in the mutation-negative one. In addition, the number of patients with microsatellite instability-positive cancers in the mutation-positive group was higher than that in the mutation-negative one. Our results suggest firstly that the hMSH2 gene plays a much more important role than hMLH1 in the carcinogenesis of Japanese HNPCC patients, secondly that the rate of hMSH2 and hMLH1 mutations is high in the kindreds satisfying the Amsterdam criteria and thirdly that both the clinical phenotypes (early onset, vertical transmission and multiplicity of tumors) and the microsatellite instability status are important for the genetic screening of HNPCC.

Gradient ion-pair high-performance liquid chromatographic method for analysis of 3-hydroxypyridin-4-one iron chelators

A gradient ion-pair HPLC separation of highly hydrophilic 3-hydroxypyridin-4-one (HPO) iron chelators is described. The separation of HPOs was performed using a reversed-phase polymer HPLC column (PLRP-S 100 A, 15x0.46 cm ID, 5 microm). The ion-pair buffer contained 1-heptanesulfonic acid (sodium salt) (5 mM) and the pH was adjusted to 2.0 using HCl. The gradient was 2%-35% CH3CN in 20 min and post-run was followed for 5 min using 2% CH3CN and 98% buffer. The flow-rate was 1 ml/min and the analytes were monitored at 280 nm. The retention times of 30 hydrophilic HPOs fell in the range of 10-18 min with sharp peak shapes, although these iron chelators possess various functional groups and distribution coefficients. The application of this HPLC method in the analysis of HPO chelators and their metabolites in rat bile and urine is described.

Two divergent signaling pathways for TGF-beta separated by a mutation of its type II receptor gene

Transforming growth factor beta (TGF-beta) can inhibit epithelial cell growth and induce extracellular matrix formation through signal transduction via its two receptors and its downstream intracellular Smad proteins. We recently reported a germline mutation, i.e., substitution of methionine for threonine at codon 315 in the kinase subdomain IV, of the TGF-beta type II receptor gene in a kindred of hereditary nonpolyposis colorectal cancer without microsatellite instability and found that the mutant receptor abolished the signal transduction for growth inhibition by TGF-beta. In this study, we performed further functional analysis of this mutant receptor. The results showed that, in contrast to its failure to mediate growth inhibition by TGF-beta, the mutant receptor still retained the ability to induce one of the extracellular matrix proteins, plasminogen activator inhibitor type 1, upon TGF-beta treatment. However, coincident with its failure to mediate growth inhibition by TGF-beta, the mutant receptor failed to transcriptionally upregulate one of the cyclin-dependent kinase inhibitors, p15(INK4B), in response to TGF-beta. These data suggest that threonine 315 of the TGF-beta type II receptor is dispensable for extracellular matrix protein production, but is essential for the growth inhibition by TGF-beta, and that the lack of growth inhibition due to the mutant receptor is possibly mediated through its failure to upregulate p15(INK4B).

Synthesis, physicochemical properties and biological evaluation of aromatic ester prodrugs of 1-(2'-hydroxyethyl)-2-ethyl-3-hydroxypyridin-4-one (CP102): orally active iron chelators with clinical potential

The synthesis of seven aromatic ester derivatives of 1-(2'-hydroxyethyl)-2-ethyl-3-hydroxypyridin-4-one is described. These ester prodrugs have been designed to target iron chelators to the liver, the major iron storage organ. In principle this should improve chelation efficacy and minimize toxicity. The distribution coefficients of these ester prodrugs between 1-octanol and MOPS buffer pH 7.4 were measured together with their rates of hydrolysis at pH 2 and pH 7.4, in rat blood and liver homogenate. Esters with heteroaromatic acid moieties were found to be less stable than benzoyl analogues. The in-vivo iron mobilisation efficacy of these ester prodrugs has been compared with that of the parent drug using a 59Fe-ferritin loaded rat model. Many prodrugs were found to enhance the ability of the parent hydroxypyridinone to facilitate 59Fe excretion. However, not all prodrugs provided increased efficacy, demonstrating that lipophilicity is not the only factor which influences drug efficacy. Furthermore, no clear correlation between efficacy and susceptibility to hydrolysis was detected. The picolinic and nicotinic ester derivatives appear to offer the best potential as prodrugs as they have a relatively low LogP value and yet lead to enhanced efficacy over the parent hydroxypyridinone.

In vivo iron mobilisation evaluation of hydroxypyridinones in 59Fe-ferritin-loaded rat model

Although there are a number of well-characterised animal models available for testing and comparing the efficacy of iron chelators, most are expensive to operate and are not capable of providing rapid and reproducible results. The method described herein is based on the labelling of rat liver with 59Fe using rat 59Fe-ferritin. This method produces highly reproducible data of the type necessary for dose-response investigations, comparison of the efficacies of different administration routes, and structure activity studies.

The development of nao li shen and its clinical application

The traditional Chinese medicine Nao Li Shen (containing ginseng, gastrodia tuber, chuanxiong rhizome and red sage root) is used in craniocerebral injury, cervical spondylosis and cerebrovascular diseases. The preparation, as an orally administered liquid, was tested in Mongolian gerbils and shown to increase tolerance to ischaemia and anoxia. Clinical use of the preparation resulted in improvement in 96% of 202 patients, as judged by right cerebral blood flow, TCD and CT examination. We conclude that Nao Li Shen has a positive curative effect upon craniocerebral injury and sequelae of cerebrovascular diseases.

Genomic structure of the transforming growth factor beta type II receptor gene and its mutations in hereditary nonpolyposis colorectal cancers

To characterize the tumorigenetic role of the transforming growth factor beta type II receptor (RII) gene, we defined its genomic structure, which consists of seven exons. The sequences of exon-intron junctions were determined to facilitate mutation analysis of each exon. Twenty-five carcinomas and five adenomas from hereditary nonpolyposis colorectal cancer patients were analyzed for mutations in the entire coding region. Four missense mutations (two in adenomas and two in carcinomas) were found in the 10 cases carrying the polyadenine deletions in one allele. These results indicate that RII shares the two-hit inactivation mechanism with tumor suppressor genes and that mutations of it may occur in the early stage of tumorigenesis.

Loss or somatic mutations of hMSH2 occur in hereditary nonpolyposis colorectal cancers with hMSH2 germline mutations

Hereditary nonpolyposis colorectal cancer (HNPCC) is a major cancer susceptibility syndrome known to be caused by the inheritance of mutations in DNA mismatch repair genes, such as hMSH2, hMLH1, hPMS1 and hPMS2. To investigate the role of genetic alterations of hMSH2 in HNPCC tumorigenesis, we analyzed 36 Japanese HNPCC kindreds as to hMSH2 germline mutations. Moreover, we also examined somatic mutations of hMSH2 or loss of heterozygosity at or near the hMSH2 locus in the tumors from the hMSH2-related kindreds. Germline mutations were detected in five HNPCC kindreds (5/36, 14%). Among them, three were nonsense mutations, one was a frameshift mutation and the other was a mutation in an intron where the mutation affected splicing. Loss of heterozygosity in four and somatic mutations in one were detected among the eight tumors with hMSH2 germline mutations. All these alterations were only detected in genomic instability(+) tumors, i.e., not in genomic instability(-) ones, indicating that mutations of hMSH2 were responsible for at least some of the tumors with genomic instability. These data establish a basis for the presymptomatic diagnosis of HNPCC patients, and constitute further evidence that both DNA mismatch repair genes and tumor suppressor genes may share the same requirement, i.e., two hits are necessary to inactivate the gene function.

Mutations of the transforming growth factor-beta type II receptor gene and genomic instability in hereditary nonpolyposis colorectal cancer

To determine the relation between the mutation of the TGF-beta type II receptor gene and genomic instability in the tumorigenesis of hereditary nonpolyposis colorectal cancer (HNPCC), we screened genomic DNA of 38 tumors from 25 HNPCC patients, 15 colorectal cancers from familial adenomatous polyposis patients, and 8 sporadic endometrial cancers, in two areas containing a (A)10 repeat or a (GT)3 repeat of the gene. Seventeen of the 24 (71%) genomic instability-positive HNPCC tumors carried one or two A deletions in the (A)10 repeat, while none of the 14 genomic instability-negative tumors did. These deletions inactivate the receptor through a frameshift mutation and the resultant protein truncation. No mutation was detected in the (GT)3 repeat sequence, but we found a missense mutation of codon 537 in the same area in one tumor. One A deletion was also detected in a genomic instability-positive sporadic endometrial cancer, but none in familial adenomatous polyposis tumors. No mutations were detected in the corresponding normal cells of these cases, indicating a somatic mutation. These data suggest that the TGF-beta type II receptor gene is a major target of genomic instability in HNPCC tumorigenesis.

[Effect of arginine supplementation on T-lymphocyte function in burn patients]

It is well accepted that nutritional support improves the immunologic functions in burn patients. Arginine has been demonstrated to have tissue--specific properties which influence certain components of the immune system. A series of experiments were carried out in this study, in order to evaluate the immune effect of arginine on T lymphocyte functions in burn patients. Two groups of burn patients with comparable clinical protocol receiving same nutritional administration except the amount of arginine in the nutrients were studied. In one group, 2% of energy supplied by arginine was added in their nutrients, while, the control group received 2% of energy from amino acid compounds instead. The T lymphocyte immune parameters were determined on days 3, 7, 14, 21 and 28 postburn. The data showed that the 2% of total energy supplied by arginine was found to significantly enhance the T lymphocyte response to PHA, CD4 phenotype expression, CD4/CD8 ratio, IL-2 production and IL-2 receptor expression, as compared with the control group. It suggests arginine should become one of the most important nutrients supplied to burn patients.

[The depressive disorder in burn patients]

The CES-D, HAMD and ABSH scales were used to assess the incidence of depressive disorder in 30 burn patients during hospitalization and in 26 patients after they re-entered the society. The results indicated that the occurrence of depressive symptoms (70%) and depression (40%) in hospitalized burn patients increased significantly as compared to the control group and a group of surgical patients. Furthermore, 30 burn patients were divided into three groups according to the extent and the site of their burns, and it was found that the incidence of depressive symptoms and the degree of depressive reaction both in group I (TBSA = 55.44 +/- 22.09%) and group III (TBSA = 6.03 +/- 6.03%, with electrical injury, facial burn, hot roller injury) were significantly higher than those in group II (TBSA = 5.49 +/- 4.19%), but there was no statistical difference between group I and group III. The incidence of depressive symptoms assessed by the CES-D scale in burn patients after they re-entered the society increased obviously as compared with normal control (46.15% vs. 10%). Furthermore, there was a negative correlation between CES-D scores andse. ABSH scorThe CES-D score was also found to be negatively correlated to the scores in four aspects (physical, mental, social and general) in ABSH scale. We conclude that burn injuries can complicate the depressive disorder. Cosmetic deformity and loss of function may be the main causes of the increase in the incidence of depressive disorder during hospitalization, while the occurrence of depressive disorder when they re-entered the society may be related to physical disabilities, mental status and social adaptability.

[Changes in plasma immunologic reactive beta-endorphin and their effect on lymphocyte response to phytohemagglutinin after thermal injury]

The study of immunosuppression after thermal injury has aroused great interest. The present study is an investigation of changes of plasma ir-beta EP in patients and their effect on lymphocyte responses to PHA following thermal injury, in order to establish a relationship between the immune and neuroendocrine system. Plasma ir-beta EP in eighteen burn patients was determined using the radioimmunoassay. At the same time, autoplasma and the autoplasma treated with anti-beta EP serum had been both tested for their effect on lymphocyte responses to PHA. The levels of plasma ir-beta EP were found to be elevated significantly in every phases during the first three days postburn (P < 0.0005-P < 0.001), and then declined to the normal level on the fourth or fifth day postburn. The lymphocytes cultured with autoplasma showed their inhibited responses to PHA during the first three days postburn and returned to normal on the fourth or fifth day postburn, while the autoplasma treated with anti-beta EP serum had an effect to improve the lymphocyte responses to PHA. The findings suggest that burn stress is a strong stimulation which may elevate plasma ir-beta EP and which in turn decrease the lymphocyte response to PHA. We assume that increased plasma ir-beta EP may be one of the main causes of immunosuppression after thermal injury.

Clinical application of a patient-controlled apparatus for ventricular administration of morphine in intractable pain: report of 28 cases

The authors developed a patient-controlled apparatus (L-224) for ventricular administration of pain-relieving medication and utilized it in the treatment of 28 patients with intractable pain. The initial dose of morphine hydrochloride was 1 mg, which afforded pain relief for an average of 170 hours. At an average dose of 1.8 mg, the average time of pain relief obtained was 137 hours. Therefore, they conclude that L-224 is a satisfactory apparatus for the ventricular administration of pain medication; it is patient controlled, safe, and reliable in clinical application.

Immunocytochemical and electron microscopic study of hepatitis B virus antigen and complete particle production in hepatitis B virus DNA transfected HepG2 cells

The relationship between the presence of hepatitis B virus antigens, their localization and hepatitis B virus replication was studied in different clones of cultured HepG2 hepatoblastoma cells transfected with cloned hepatitis B virus DNA. Intracellular hepatitis B virus antigens were detected by immunofluorescence. The production of these antigens was evaluated in the culture media by enzyme-linked immunoassay. Hepatitis B virus DNA was detected using dot-blot hybridization. Three types of HBcAg staining were observed in transfected HepG2 cells: (a) cells with nuclear HBcAg, (b) cells with cytoplasmic HBcAg and (c) cells with both nuclear and cytoplasmic HBcAg. Cell types b and c also expressed hepatitis B virus DNA in their culture media. Our results suggest that cytoplasmic HBcAg may be more involved than nuclear HBcAg in hepatitis B virus replication. The site of hepatitis B virus formation in hepatocytes was studied by electron microscopic examination of a specific hepatitis B virus producer clone, thereby allowing detection of intracellular Dane particles more easily than liver biopsy samples from infected patients. Dane particles and HBsAg filaments were found in large, dilated structures probably related to the endoplasmic reticulum. Budding of core particles into cisternae of endoplasmic reticulum-related structures appears to be a possible mechanism for hepatitis B virus formation; our results suggest that the exocytosis of cisternae to extracellular spaces may be a mechanism for release of hepatitis B virus particles.

Selection of a Brucella vaccine strain of low residual virulence by chemical mutagenesis

Following incubation of the oral vaccine Brucella suis strain 2 with diethyl sulphate (DES), a mutant designated strain S105 was selected by screening surviving bacteria for reduced virulence for mice. Strain 105 also showed low residual virulence for guinea-pigs and, unlike the parent strain, did not initiate abortion in pregnant sheep and goats after parenteral administration. Nevertheless, it was as effective as the parent strain in stimulating protective immunity to Brucella melitensis when given as an oral vaccine to sheep under both experimental and field conditions.

Retinal adaptation effects on the patterned VEP and ERG

The patterned visually evoked potential (pVEP) and patterned electroretinogram (pERG) after light and dark adaptation were investigated in 10 visually normal human observers. The influence of retinal preadaptation on the pVEP appeared to be dependent on the stimulus field size. With a 6 degree field size retinal adaptation effects were not apparent, but with a 12 degree field size the amplitudes of the dark-adapted steady-state pVEP (ssVEP) and transient pVEP (tVEP) were significantly larger than the light-adapted amplitudes. Similarly pERG's elicited by a 12 degree field size produced larger amplitude dark-adapted results. The implications of these findings are discussed. Monitoring the temporal changes in the pVEP subsequent to different retinal preadaptation levels proved to be inconclusive for the conditions studied.