[Clinical application of a classification based on crucial curvature of coronal imbalance in degenerative lumbar scoliosis]

Objective: To present efficacy of clinical application of a classification based on crucial curvature of coronal imbalance in degenerative lumbar scoliosis (DLS). Methods: A case series study. Clinical data of 61 cases (8 males, 53 females) who underwent posterior correction surgery for DLS from January 2019 to January 2021 were retrospectively analyzed. The mean age was (71.7±6.2) years (ranged 60-82 years). According to the direction of C₇ plumb line (C₇PL) deviated from central sacral vertical line (CSVL) and orientation of L₄ coronal tilt, the author determined which one was the crucial curve. If C₇PL deviated from CSVL in the same direction as concave side of the thoracolumbar curve and L₄ coronally tilts opposite direction of C₇PL deviates from CSVL, then the crucial curve was thoracolumbar curve (type 1). On the contrary, if C₇PL deviated from CSVL in the same direction as concave side of the lumbosacral curve and L₄ coronally tilts consist with direction of C₇PL deviates from CSVL, then the crucial curve was lumbosacral curve (type 2). According to absolute value of coronal balance distance (|CBD|), each type of patients was divided into two groups, respectively, namely coronal balance (CB) (|CBD|≤3 cm) and coronal imbalance (CIB) (|CBD|>3 cm). Changes of Cobb angles of thoracolumbar curve and lumbosacral curve and CBD were recorded and analyzed. Results: The rate of preoperative CIB was 55.7% (34/61) in all the patients. Of the patients, 23 cases were classified as type 1 and 38 cases as type 2. The rate of preoperative CIB was 34.8% (8/23) in type 1 patients and 68.4% (26/38) in type 2. The rate of postoperative CIB was 27.9% (17/61) in all the patients, with 13.0% (3/23) in type 1 and 36.8% (14/38) in type 2. The |CBD| of CB group in type 1 patients decreased from (2.6±1.4) cm before the operation to (1.5±1.0) cm after (P=0.015); and the correction rate of thoracolumbar curve (68.8%±18.4%) was significantly higher than that of lumbosacral curve (34.5%±23.9%) (P=0.005). The |CBD| of CB group in type 2 patients decreased from (2.6±3.0) cm before the operation to (1.6±1.2) cm after (P=0.027); the correction rate of lumbosacral curve (71.3%±18.6%) was higher than that of thoracolumbar curve (57.3%±21.1%), but the difference was not statistically significant (P=0.546). There was no significant difference in |CBD| of CIB group in type 2 patients before and after the operation (P=0.222); the correction rate of lumbosacral curve (38.3%±14.8%) was significantly lower than that of thoracolumbar curve (53.6%±16.0%) (P=0.001). There was a correlation between the change of CBD (3.8±1.5) cm and the difference in correction rate between thoracolumbar and lumbosacral curve (32.3%±19.6%) in CB group in type 1 patients after surgery (r=0.904, P<0.001). There was a correlation between the change of CBD (1.9±2.2) cm and the difference in correction rate between lumbosacral and thoracolumbar curve (14.0%±26.2%) in CB group in type 2 patients after surgery (r=0.960, P<0.001). Conclusion: Clinical application of a classification based on crucial curvature of coronal imbalance in DLS is satisfactory, and its combination with matching correction can effectively prevent the occurrence of coronal imbalance after spinal correction surgery.

Risk Factors for the Co-infection with HIV, Hepatitis B and C Virus in Syphilis Patients

Syphilis, human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV) share transmission routes. Syphilis infection can increase the risk of acquiring and transmitting HIV in key populations. The aims of this study were to investigate the risk factors and co-infection patterns for HIV, HBV and HCV in patients with syphilis. A retrospective study was conducted of 2,412 patients with syphilis (1,922 (79.68%) with latent syphilis, 336 (13.93%) with secondary syphilis, 78 (3.23%) with primary syphilis, 72 (2.99%) with tertiary syphilis, and 4 (0.17%) with congenital syphilis). Positive results were observed in 8.21% (134/1,620) of patients tested for HIV, 5.75% (82/1,427) for HBV, and 1.02% (14/1,374) for HCV, respectively. Multivariate logistic regression analysis found that male sex (adjusted odds ratio (AOR) 26.03; 95% confidence interval (CI) 10.37–65.36), age < 55 years, especially age group 25–34-years (AOR 8.06; 95% CI 4.16–15.61), diagnosed at the Department of Infectious Disease (AOR 19.16; 95% CI 9.74–37.69), patients from Southern China, which is a geographical area south of the Qinling-Huaihe line (AOR 1.86; 95% CI 1.06–3.26) and having a rapid plasma reagin titre ≥ 1:32 (AOR 1.88; 95% CI 1.12–3.15) were independently associated with HIV infection. Risk factors for HBV co-infection in patients with syphilis, including male sex (AOR 1.78; 95% CI 1.12–2.83) and living in Southern China (AOR 4.66; 95% CI, 2.36–9.17) were also identified.

[A multicenter randomized prospective study of concurrent chemoradiation with 60 Gy versus 50 Gy for inoperable esophageal squamous cell carcinoma]

Objective: To determine whether 60 Gy is superior to standard 50 Gy for definitive concurrent chemoradiation(CCRT) in esophageal squamous cell carcinoma (ESCC) using modern radiation technology in a phase Ⅲ prospective randomized trial. Methods: From April 2013 to May 2017, 331 patients from 22 hospitals who were pathologically confirmed with stage ⅢA-ⅣA ESCC were randomized to 60 Gy or 50 Gy with random number table. Total of 305 patients were analyzed, including 152 in 60 Gy group and 153 in 50 Gy group. The median age was 63 years, 242(79.3%) males and 63(20.7%) females. The median length of primary tumor was 5.6 cm. The clinical characteristics between two groups were comparable. All patients were delivered 2 Gy per fraction, 5 fractions per week. Concurrent weekly chemotherapy with docetaxel (25 mg/m(2)) and cisplatin (25 mg/m(2)) and 2 cycles consolidation chemotherapy with docetaxel (70 mg/m(2)) and cisplatin (25 mg/m(2), d1-3) were administrated. The primary endpoint was local/regional progression-free survival (LRPFS). The data were compared with Pearson chi-square test or Fisher's exact test. Results: At a median follow-up of 27.3 months, the disease progression rate was 37.5% (57/152), 43.8% (67/153) in the high and standard-dose group, respectively (χ(2)=1.251, P=0.263). The 1, 2, 3-year LRPFS rate was 75.4%, 56.8%, 52.1% and 74.2%, 58.4%, 50.1%, respectively (HR: 0.95, 95%CI: 0.69-1.31, P=0.761). The 1, 2, 3-year overall survival rate was 84.1%, 64.8%, 54.1% and 85.4%, 62.9%, 54.0%, respectively (HR: 0.98, 95%CI: 0.71-1.38, P=0.927). The 1, 2, 3-year progression-free survival rate was 70.8%, 54.2%, 48.5% and 65.5%, 51.9%, 45.1%, respectively (HR: 0.93, 95%CI: 0.68-1.26, P=0.621). The incidence rates in toxicities between the two groups were similar except for higher rate of severe pneumonitis in high dose group (χ(2)=11.596, P=0.021). Conclusions: The efficacy in disease control is similar between 60 Gy and 50 Gy using modern radiation technology concurrent with chemotherapy for ESCC. The 50 Gy should be recommended as the regular radiation dose with CCRT for ESCC.

[One-stage posterior correction and second-stage anterior debridement and fusion in treating children with thoracic tuberculosis complicated with kyphoscoliosis]

Objective: To investigate the clinical outcomes of one-stage posterior correction surgery and second-stage anterior debridement and fusion in treating children with thoracic tuberculosis complicated with kyphoscoliosis. Methods: From January 2008 to December 2014, a total of 17 children with thoracic vertebral tuberculosis complicated with kyphoscoliosis who underwent a one-stage posterior correction and second-stage anterior debridement and complementary fusion were included. There were 8 males and 9 females with an average age of (8±4) years (5-14 years). All patients underwent posterior correction and anterior debridement and bone graft fusion surgery. The neurological function was determined by Frankel grade. The operation time, estimated blood loss (EBL), levels fused and numbers of screws were recorded. The following radiographic parameters were measured: Cobb angle of the coronal curve, regional kyphosis and sagittal vertical axis (SVA). The incidence of intraoperative and postoperative complications was recorded. The data before and after the operation were compared with paired sample t test. Results: The tuberculosis lesions located in the thoracic vertebrae, and the abscess involved 2 to 4 vertebral segments. The average operation time was (4.1±0.8) h, the EBL was (526±275) ml, the levels fused were 7.6±2.3, and 173 pedicle screws were placed. The preoperative coronal curve averaged 12.6°±6.2°, and it was corrected to 4.2°±1.9° postoperatively (t=4.628, P<0.01), the regional kyphosis was 67.2°±19.4°, and it was corrected to 15.7°±8.2° postoperatively (t=8.192, P<0.01). The SVA improved from (8.1±5.0) mm to (3.0±1.7) mm postoperatively. The mean duration of follow-up for all the patients were (38±11) months. At final follow-up, SVA was reduced to (2.4±2.0) mm and the other parameter kept stable. Thirteen patients had more than one grade improvement of Frankel grade. The VAS score for all patients improved from 4.7±2.8 to 2.2±0.5 postoperatively (t=3.973, P=0.01), and improved to 0.5±0.5 at final follow-up (t=-7.880, P<0.01). No recurrence of primary spinal tuberculosis was seen at final follow-up of all patients. Conclusions: One-stage posterior correction and second-stage anterior complementary debridement and fusion is an effective procedure for children with thoracic tuberculosis complicated with kyphoscoliosis. Significant postoperative deformity correction could be achieved with satisfactory improvement of neurological function. Solid fusion and satisfactory correction maintenance were observed at mid-to long-term follow-up.

[Correlation between syrinx resolution after posterior fossa decompression and cervical sagittal profile change in adolescents with Chiari malformation and syringomyelia]

Objective: To evaluate the long term change of the cervical sagittal profile in adolescent Chiari malformation type Ⅰ (CMI)/syringomyelia undergoing posterior fossa decompression (PFD) and to further evaluate the correlation between the syrinx resolution and cervical sagittal profile. Methods: A retrospective radiographic study was performed in 32 adolescents undergoing PFD for CMI/syringomyelia from October 2011 to August 2015 with a minimum 2-year follow-up. There were 23 males and 9 females, with a mean age of (13.7±2.8) years (range, 10-16 years). The following parameters including upper cervical angle (C(0)-C(2)), lower cervical angle (C(2)-C(7)), sagittal balance (C(2)-C(7)SVA), cervical curvature index (CCI), syrinx size and length were compared preoperatively and at the last follow-up. The correlation of syrinx resolution and cervical sagittal parameters were further analyzed with Pearson correlation analysis. Results: All patients received a followed-up for 2.0-6.5 years [mean (3.9±1.1) years]. The lower cervical angle and CCI were-29.8°±11.4° and 29.1%±7.1% at the last follow-up, respectively, which were significantly higher than those before surgery (-15.2°±8.8°, 13.4%±4.2%)(t=2.917, 2.902, both P<0.05). The syrinx size and length were also obviously decreased at the last follow-up. No significant difference was found in the upper cervical angle and C(2)-C(7)SVA before operation and at the last follow-up (t=0.302, 0.871, both P>0.05). There were significantly positive correlations between the differences of syrinx width and the lower cervical angle, and the CCI before and after surgery (r=0.611, 0.652, both P<0.05). Significantly positive correlations were also observed between the differences of syrinx length and the lower cervical angle, and the CCI before and after surgery (r=0.504, 0.514, both P<0.05). Conclusions: The cervical lordosis can be restored after PFD in adolescents with CMI/syringomyelia. The resolution of syrinx may play an important role in restoring the cervical sagittal alignment.

[Clinical features of adult patients with chronic active Epstein-Barr virus infection]

Objective: To investigate the clinical features of adult-onset chronic active Epstein-Barr virus infection (CAEBV). Methods: A total of 21 adult patients with CAEBV who were admitted to the department of General Internal Medicine at Peking Union Medical College Hospital from January 2006 to January 2016 were retrospectively analyzed. Demographic data, disease duration, clinical manifestations, laboratory findings, treatments and prognosis were reviewed. Results: Eighteen females and 3 males were enrolled with a mean age of 39 years. The most common clinical manifestations included fever in 20 patients, splenomegaly in 20 patients, lymphadenopathy in 18 patients, and hepatomegaly in 10 patients, followed by laryngopharyngeal disorders in 6 patients, pleural effusion and peritoneal effusion each in 5 patients, rash in 4 patients, interstitial lung disease in 3 patients, gastrointestinal hemorrhage in 2 patients, and peripheral neuropathy and pulmonary hypertension each in 1 patient. Six patients were complicated with hemophagocytic lymphohis-tioncytosis(HLH) that developed 5-17 (mean: 9) months following CAEBV onset, all of whom experienced hyperpyrexia, pancytopenia, lymphadenopathy, splenomegaly, and liver dysfunction, 3 with hepatomegaly. Nineteen of the 21 patients had received steroid therapy including 10 combined with immunosuppressive agents, 11 with antiviral therapy, and 8 with intravenous immunoglobulin. Thirteen patients died, including 10 of multiple organ failure, (including 6 of HLH) 2 of severe pulmonary infection, and 1 of lymphoma. Six patients remained on follow-up, yet 2 were missing. Conclusions: CAEBV is expected with severe condition and poor prognosis, which is likely to be complicated with HLH. Clinical physicians should pay attention to adult patients with fever, hepatosplenomegaly and lymphadenopathy, which suggests possible CAEBV.

[Genetic analysis of posterior cranial fossa morphology in families of Chiari malformation type Ⅰ]

Objective: To explore genetic characteristic of posterior cranial fossa morphology in families of Chiari malformation type Ⅰ (CMI). Methods: From April 2010 to May 2016, a total of 47 cases of CMI families (CMI group) and their 94 parents (CMI-P group)collected were retrospectively reviewed in Department of Spinal Surgery, Drum Tower Hospital, School of Medicine, Nanjing University.Another cohort of 50 asymptomatic adults was enrolled to serve as the control group.Patients with skull fracture or other diseases which can lead to secondary CMI were excluded.On mid-sagittal T2-weighted magnetic resonance (MR) imaging, four measurements were evaluated and compared between these three groups, including the length of cerebellar tonsillar descent, the area of posterior cranial fossa(PCF area), the area of the brain tissue in posterior cranial fossa (PCF tissue area), and the PCF crowdedness indexes (PCF tissue area/ PCF area×100%). Results: Totally 47 CMI patients (21 males and 26 females; mean age, 16.4 years), 94 parents (47 males and 47 females; mean age, 39.2 years) and 50 controls (23 males and 27 females; mean age, 22.3 years) were recruited in this study.Significant differences in all four indexes were found between CMI group and the control group.The length of cerebellar tonsillar descent were much bigger in CMI-P group than in the control group (1.5±2.2 mm vs -0.9±1.1 mm), with 7 cases reach the diagnostic criteria of Chiari malformation(≥5 mm) and one with syingomyelia.Compared to the control group, CMI-P group had smaller PCF area, and its PCF crowdedness indexes averaged 90.0% as between the control group (85.3%) and the CMI group (93.6%). Conclusions: In CMI families, parents have similar posterior cranial fossa abnormalities with their CMI children, presenting obviously narrow and crowded.Their PCF crowdedness indexes are between normal subjects and CMI patients, and their cerebellar tonsils are lower, even some parents are also CMI patients, suggesting genetic mechanisms involved in the development of CMI.

p21Waf1/Cip1 plays a critical role in modulating senescence through changes of DNA methylation

It has been reported that genomic DNA methylation decreases gradually during cell culture and an organism's aging. However, less is known about the methylation changes of age-related specific genes in aging. p21(Waf1/Cip1) and p16(INK4a) are cyclin-dependent kinase (Cdk) inhibitors that are critical for the replicative senescence of normal cells. In this study, we show that p21(Waf1/Cip1) and p16(INK4a) have different methylation patterns during the aging process of normal human 2BS and WI-38 fibroblasts. p21(Waf1/Cip1) promoter is gradually methylated up into middle-aged fibroblasts but not with senescent fibroblasts, whereas p16(INK4a) is always unmethylated in the aging process. Correspondently, the protein levels of DNA methyltransferase 1 (DNMT1) and DNMT3a increase from young to middle-aged fibroblasts but decrease in the senescent fibroblasts, while DNMT3b decreases stably from young to senescent fibroblasts. p21(Waf1/Cip1) promoter methylation directly represses its expression and blocks the radiation-induced DNA damage-signaling pathway by p53 in middle-aged fibroblasts. More importantly, demethylation by 5-aza-CdR or DNMT1 RNA interference (RNAi) resulted in an increased p21(Waf1/Cip1) level and premature senescence of middle-aged fibroblasts demonstrated by cell growth arrest and high beta-Galactosidase expression. Our results suggest that p21(Waf1/Cip1) but not p16(INK4a) is involved in the DNA methylation mediated aging process. p21(Waf1/Cip1) promoter methylation may be a critical biological barrier to postpone the aging process.

RT-PCR heteroduplex analysis permits differentiation of transgene and host gene expression in a transgenic animal model

In transgenic animal models, the conservation of DNA sequences between the transgene and the host wild-type gene can complicate the evaluation of the expression of each gene. The potential for gene silencing may complicate matters further. Here we report the use of RT-PCR heteroduplex analysis to differentiate the expression of a transgene and its homologous wild-type, even when these genes are very similar in their respective DNA sequences. We designed RT-PCR primers to amplify identically sized 243-bp fragments within the DNA binding domain of the p53 gene from both human and mouse mRNA samples. Ten samples from human p53 (273H) transgenic mice and 10 samples from wild-type controls were tested. Heteroduplex bands were formed in all transgenic samples but were absent from all wild-type samples. In addition, RT-PCR heteroduplex analysis was able in one sample to differentiate a silenced transgene from its wild-type allele, without the assistance of sequencing or labeling. In summary, the RT-PCR heteroduplex analysis is easy to use and has the ability to screen a large number of samples in a short time. The RT-PCR heteroduplex analysis is especially useful for the detection of expression when a transgene and the host homologous endogenous allele are too conserved in sequence to design species-specific RT-PCR primers.

Increased expression of unmethylated CDKN2D by 5-aza-2'-deoxycytidine in human lung cancer cells

DNA hypermethylation of CpG islands in the promoter region of genes is associated with transcriptional silencing. Treatment with hypo-methylating agents can lead to expression of these silenced genes. However, whether inhibition of DNA methylation influences the expression of unmethylated genes has not been extensively studied. We analysed the methylation status of CDKN2A and CDKN2D in human lung cancer cell lines and demonstrated that the CDKN2A CpG island is methylated, whereas CDKN2D is unmethylated. Treatment of cells with 5-aza-2'-deoxycytidine (5-Aza-CdR), an inhibitor of DNA methyltransferase 1, induced a dose and duration dependent increased expression of both p16(INK4a) and p19(INK4d), the products of CDKN2A and CDKN2D, respectively. These data indicate that global DNA demethylation not only influences the expression of methylated genes but also of unmethylated genes. Histone acetylation is linked to methylation induced transcriptional silencing. Depsipeptide, an inhibitor of histone deacetylase, acts synergistically with 5-Aza-CdR in inducing expression of p16(INK4a) and p19(INK4d). However, when cells were treated with higher concentrations of 5-Aza-CdR and depsipeptide, p16(INK4a) expression was decreased together with significant suppression of cell growth. Interestingly, p19(INK4d) expression was enhanced even more by the higher concentrations of 5-Aza-CdR and depsipeptide. Our data suggest that p19(INK4d) plays a distinct role from other INK4 family members in response to the cytotoxicity induced by inhibition of DNA methylation and histone deacetylation.

Translocation of MRE11 from the nucleus to the cytoplasm as a mechanism of radiosensitization by heat

Zhu, W-G., Seno, J. D., Beck, B. D. and Dynlacht, J. R. Translocation of MRE11 from the Nucleus to the Cytoplasm as a Mechanism of Radiosensitization by Heat. Radiat. Res. 156, 95-102 (2001).Hyperthermia sensitizes mammalian cells to ionizing radiation, presumably by inhibiting the repair of radiation-induced double-strand breaks (DSBs). However, the mechanism by which heat inhibits DSB repair is unclear. The nuclear protein MRE11 is a component of a multi-protein complex involved in nonhomologous end joining (NHEJ) of radiation-induced DSBs. Using one-dimensional sodium dodecylsulfate polyacrylamide gel electrophoresis and Western blotting, we found that MRE11 is translocated from the nucleus to the cytoplasm when human U-1 melanoma or HeLa cells are heated for 15 min at 45.5 degrees C or when cells are heated after irradiation with 12 Gy of X rays. No such translocation is observed in unheated irradiated cells. The kinetics of migration of MRE11 to the cytoplasm was dependent upon whether the heated cells were irradiated, while the magnitude of redistribution of MRE11 was dependent upon post-treatment incubation time at 37 degrees C. Cytoplasmic MRE11 content reached a maximum 2-4 h after heating; the increase was not due to new protein synthesis. Partial recovery of nuclear MRE11 content was observed when heated cells or heated irradiated cells were incubated for up to 7 h at 37 degrees C after treatment. Western blotting results showing translocation of MRE11 from the nucleus to the cytoplasm after heating and irradiation were confirmed using confocal microscopy and immunofluorescence staining of fixed cells. Our data suggest that radiosensitization by heat may be caused, at least in part, by translocation of the DNA repair protein MRE11 from the nucleus to the cytoplasm.

DNA methyltransferase inhibition enhances apoptosis induced by histone deacetylase inhibitors

Histone acetylation has long been associated with transcriptional activation, whereas conversely, deacetylation of histones is associated with gene silencing and transcriptional repression. Here we report that inhibitors of histone deacetylase (HDAC), depsipeptide and trichostatin A, induce apoptotic cell death in human lung cancer cells as demonstrated by DNA flow cytometry and Western immunoblot to detect cleavage of poly(ADP-ribose) polymerase. This HDAC inhibitorinduced apoptosis is greatly enhanced in the presence of the DNA methyltransferase inhibitor, 5-aza-2'-deoxycytidine (DAC). The HDAC inhibitor-induced apoptosis appears to be p53 independent, because no change in apoptotic cell death was observed in H1299 cells that expressed exogenous wild-type p53 (H1299 cells express no endogenous p53 protein). To further investigate the mechanism of DAC-enhanced, HDAC inhibitor-induced apoptosis, we analyzed histone H3 and H4 acetylation by Western immunoblotting. Results showed that depsipeptide induced a dose-dependent acetylation of histones H3 and H4, which was greatly increased in DAC-pretreated cells. By analyzing the acetylation of specific lysine residues at the amino terminus of histone H4 (Ac-5, Ac-8, Ac-12, and Ac-16), we found that the enhancement of HDAC inhibitor-induced acetylation of histones in the DAC-pretreated cells was not lysine site specific. These results demonstrate that DNA methylation status is an important determinant of apoptotic susceptibility to HDAC inhibitors.

Electrical stimulation of neonatal cardiac myocytes activates the NFAT3 and GATA4 pathways and up-regulates the adenylosuccinate synthetase 1 gene

Electrically stimulated pacing of cultured cardiomyocytes serves as an experimentally convenient and physiologically relevant in vitro model of cardiac hypertrophy. Electrical pacing triggers a signaling cascade that results in the activation of the muscle-specific Adss1 gene and the repression of the nonmuscle Adss2 isoform. Activation of the Adss1 gene involves the calcineurin-mediated dephosphorylation of NFAT3, allowing its translocation to the nucleus, where it can directly participate in Adss1 gene activation. Mutational studies show that an NFAT binding site located in the Adss1 5'-flanking region is essential for this activation. Electrical pacing also results in the increased synthesis of GATA4, another critical cardiac transcription factor required for Adss1 gene expression. MEF2C also produces transactivation of the Adss1 gene reporter in control and paced cardiac myocytes. Using the Adss1 gene as a model, these studies are the first to demonstrate that electrical pacing activates the calcineurin/NFAT3 and GATA4 pathways as a means of regulating cardiac gene expression.

Heat-induced modulation of lamin B content in two different cell lines

Previous work in our laboratory indicates that the nuclear matrix protein lamin B is a "prompt" heat shock protein, which increases significantly when human U-1 melanoma and HeLa cells are exposed to 45.5 degrees C for 5-40 min. Using Western blotting, we found that the lamin B content in U-1 and HeLa cells increased to a greater extent during post-heat incubation at 37 degrees C than during the heat dose itself. When HeLa cells were heated at 45.5 degrees C for 30 min, and then incubated at 37 degrees C for up to 7 h, lamin B content was increased significantly (1.69-fold maximum increase at 3 h) compared to unincubated heated cells. Also, thermotolerant HeLa cells showed a greater increase (up to 1.72-fold) in lamin B content during subsequent heating compared to nontolerant cells. The increase in lamin B content in thermotolerant cells, or when heated cells were incubated at 37 degrees C, was also observed in U-1 cells. HeLa cells heated in the presence of glycerol (a heat protector) showed a 1.21-1.72-fold increase in lamin B content compared to cells heated for 10-30 min without glycerol. In contrast, lamin B content decreased 1.23-1.85-fold when cells were heated for 10-30 min in the presence of procaine (a heat sensitizer) compared to cells heated without procaine. These data suggest that lamin B may play an important role in the heat shock response, and that modulation of lamin B content by heat sensitizers or protectors may play a role in regulation of heat sensitivity.

Long-term tumor resistance induced by laser photo-immunotherapy

An ideal treatment modality for metastasizing tumors should eradicate the primary tumor and elicit a systemic, tumor-selective response leading to elimination of metastases and long-term tumor resistance. Also, it should be induced by local treatment at the primary site, to limit adverse systemic effects. A new method for treating metastatic tumors which utilizes a combination of a near-infrared laser, a photosensitizer and an immunoadjuvant has been developed. It involves intra-tumor injection of the sensitizer/adjuvant solution, followed by local non-invasive laser irradiation. It has produced regression and total eradication of treated primary tumors and untreated metastases at remote sites against mammary tumors in rats. Successfully treated tumor-bearing rats showed total tumor resistance to subsequent tumor rechallenge. Our histochemical results showed that sera from cured tumor-bearing rats contained antibodies that bound strongly to the plasma membrane of both living and preserved tumor cells. Western blot analysis of tumor cell proteins using sera from successfully treated rats as the source of primary antibodies also showed distinct bands, indicating induction of tumor-selective antibodies. Our findings indicate that a systemic, long-term effect on metastatic tumors can be induced by local application of laser photo-immunotherapy.

Lamin B is a prompt heat shock protein

The cellular response to hyperthermia involves the increased synthesis of heat shock proteins (HSPs) within several hours after treatment. In addition, a subset of proteins has been shown to be increased immediately after heating. These "prompt" HSPs are predominantly found in the nuclear matrix-intermediate filament fraction and are not present or detectable in unheated cells. Since the nuclear matrix has been suggested to be a target for heat-induced cell killing, prompt HSPs may play a prominent role in the heat shock response. Using Western blotting and flow cytometry, we found that an increase in the synthesis of lamin B, one of the major proteins of the nuclear lamina, is induced during heating at 45.5 degrees C but not during heating at 42 degrees C. Since it is an abundant protein which is constitutively expressed in mammalian cells, lamin B appears to be a unique member of the prompt HSP family. The kinetics of induction of lamin B during 45.5 degrees C heating did not correlate with the dose-dependent reduction in cell survival. While increased levels of lamin B during 45.5 degrees C heating do not appear to confer a survival advantage directly, a possible role for lamin B in cellular recovery after heat shock cannot be discounted.

Post-irradiation exposure to HBSS enhances apoptosis in FM3A cells

Many types of mammalian cells can repair potentially lethal damage (PLD) when incubated in conditioned medium (C-med) or Hank.'s balanced salt solution (HBSS) after irradiation. In this study, we found that there is an increase in clonogenic survival in FM3A cells, mouse mammary carcinoma cells when cells are incubated in C-med, but not in HBSS after irradiation. HBSS was lethal to unirradiated FM3A cells, and apoptosis was observed when cells were exposed to HBSS for more than 10 hours. However, irradiated cells underwent rapid apoptotic cell death and there was a decrease in clonogenic survival when cells were incubated in HBSS for a short time (3 h). Apoptotic cell death, was decreased significantly when irradiated cells were incubated in HBSS with 2% fetal calf serum. In addition, clonogenic survival was decreased significantly when irradiated cells were incubated in C-med with cycloheximide (CHX), an inhibitor of protein synthesis. Thus, the rapid apoptotic death of irradiated FM3A cells induced by HBSS might be due to the absence of serum or inhibition of protein synthesis. Some newly synthesized proteins, or proteins normally found in serum, may be required for irradiated cells to recover from X-ray induced damage.

Dependence of induction of interphase death of Chinese hamster ovary cells exposed to accelerated heavy ions on linear energy transfer

Induction of interphase death was examined in Chinese hamster ovary cells exposed to accelerated heavy ions (carbon, neon, argon and iron) of various linear energy transfers (LETs) (10-2000 keV/microm). The fraction of cells that underwent interphase death was determined by observing individual cells with time-lapse photography (direct method) as well as by counting cells undergoing interphase death made visible by the addition of caffeine (indirect method). After exposure to X rays, interphase death increased linearly with dose above a threshold of about 10 Gy, whereas it increased at a higher rate without a threshold after exposure to high-LET heavy ions. The relative biological effectiveness (RBE) compared to X rays, as determined at the 50% level of induction, increased with LET, reached a maximum at an LET of approximately 230 keV/microm and then decreased with further increase in LET. The range of LET values corresponding to the maximum RBE appears to be narrower for interphase death than for reproductive death (120-230 keV/microm), as assayed using loss of colony-forming ability as a criterion. The inactivation cross section for interphase cell death reached a plateau of 5-10 microm2. This means that the probability for the induction of interphase death by traversal of a single heavy-ion track through the nucleus (size: about 130 microm2) is about 0.04-0.08.

Promotion of heat-induced apoptosis in FM3A cells by protease inhibitors

Although it has been shown that proteases may play a positive role in in causing apoptosis of some cells, we report here that, on the contrary, protease inhibitors can promote heat-induced apoptosis in FM3A cells. Cysteine protease inhibitor, trans-Epoxy-succinyl-L-leucylamido-(4-guanidino)butane (E-64, 100 micrograms/ml) and aspartate protease inhibitor, pepstatin-A (100 micrograms/ml) were used to test hyperthermic effect on FM3A cells and showed remarkable cytotoxicity when they were present in cell suspension during heating at 44 degrees C. The cytotoxicity was due to promotion of heat-induced apoptosis as judged by DNA agarose electrophoresis. Furthermore, using flow cytometric analysis, we observed a decrease in the G0/G1 phase cell and an increase in the S phase cell as well as increased apoptosis after heat shock. E-64 and pepstatin-A exhibited a promotive effect on the changes of cell cycle induced by heat. The data presented suggest that the enhancement of hyperthermic cell killing by protease inhibitors may be related to promotion of heat-induced apoptosis and changes of cell cycle.

Enhancement of hyperthermic killing in L5178Y cells by protease inhibitors

We have investigated the effect of protease inhibitors on hyperthermic cell killing using cultured mammalian cells (L5178Y) and found that protease inhibitors were potent hyperthermia sensitizers. At 37 degrees C, phenylmethylsulfonyl fluoride (PMSF), a serine protease inhibitor, was not cytotoxic at the concentration of 400 micrograms/ml for up to 6 h. When cells were exposed to PMSF (200-400 micrograms/ml) during heating at 43 degrees C, significant potentiation of hyperthermic cell killing was observed. Other protease inhibitors, such as chymostatin and diisopropylfluorophosphate (both are serine protease inhibitors); (2S,3S)-trans-epoxy-succinyl-L-leucylamido-3-methylbutane ethyl ester (cysteine protease inhibitor) and pepstatin-A (aspartate protease inhibitor) showed similar effects. However, when cells were heated at 43 degrees C in the presence of cycloheximide (a protein synthesis inhibitor) together with PMSF, hyperthermic enhancement by PMSF decreased markedly. A decrease in potentiating the effect of PMSF was also noted with thermotolerant cells. These facts suggest that protease inhibitors may exert their hyperthermic cell killing by inhibiting proteases and ubiquitin, which are necessary to degrade denatured proteins induced by heat.

Rainbow holographic aberrations and the bandwidth requirements

Rainbow holographic image resolution, primary aberrations, and bandwidth requirements are presented. The results obtained for the rainbow holographic process are rather general, for which the conventional holographic image resolution, aberrations, and bandwidth requirements, can be derived. The conditions for the elimination of the five primary rainbow holographic aberrations are also given. These conditions may be useful for the application of obtaining a high-quality rainbow hologram image. In terms of bandwidth requirements, we have shown that the bandwidth requirement for a rainbow holographic construction is usually several orders lower than that of a conventional holographic process. Therefore, a lower-resolution recording medium can generally be used for most of the rainbow holographic constructions.