Outcomes of extremely premature infants related to their peak serum bilirubin concentrations and exposure to phototherapy

OBJECTIVES

To analyze, in extremely low birth weight infants, associations between peak bilirubin concentration and evidence of brain damage, and between peak bilirubin concentration and blindness attributable to retinopathy of prematurity.

METHODS

Retrospective study of 128 infants of </=800 g birth weight and </=27 weeks gestation born between 1980 and 1989 and discharged from a tertiary neonatal intensive care unit. After screening analyses, multivariable analyses were conducted to identify associations between blindness and peak bilirubin concentration (dichotomized at different levels to create 3 binary variables), and between severe adverse neurodevelopmental outcome at 18 months postterm age and peak bilirubin levels.

RESULTS

Of 128 18-month survivors, 15 had severe visual loss attributable to retinopathy of prematurity, 21 had neurodevelopmental deficit, and 5 were deaf. Visual loss was significantly associated with low-peak serum bilirubin concentration (<9.4 mg/dL (<160 micromol/L) versus >/=9.4 mg/dL (odds ratio [OR] confidence interval [CI] 4.48 [1.15-17.43])), low gestational age (OR [CI] per week 1.95 [1.05-3.63]), and longer duration of phototherapy (OR [CI] per 10 hours 1.17 [1.02-1.33]). The association of neurodevelopmental impairment with grades 3 and 4 intraventricular hemorrhage was statistically significant (OR 5.39 [1.83-15.84]), but with high-peak serum bilirubin concentration >/=11.7 mg/dL (>/=200 micromol/L), was not significant (OR 2.89 [0. 87-9.53]).

CONCLUSIONS

In these infants, prolonged phototherapy and low-peak serum bilirubin concentrations were associated with severe visual loss attributable to retinopathy of prematurity. The findings should be interpreted with caution until the evidence is reinforced in other patient populations.

Intracellular transport of varicella-zoster glycoproteins

Previous observations have established that varicella-zoster virus (VZV) is enveloped in the trans-Golgi network (TGN) in cultures infected with VZV and that the glycoprotein gE is targeted to the TGN by a signal sequence (AYRV) and an acidic TGN signal patch in its cytosolic domain. Neither sequence is present in other VZV glycoproteins. Like gE, gI was targeted to the TGN when it was expressed in transfected cells, suggesting that gI also contains TGN targeting information (colocalized with gE and the AP-1 adaptin complex). In contrast, gB, gC, gH, and gL immunoreactivities were not detected in the TGN when they were expressed individually in transfected cells. In VZV-infected cells, gE, gI, gH, and gL were all concentrated in the TGN. Since VZV glycoproteins that lack targeting sequences (gB, gC, gH, and gL) concentrated in the TGN of infected cells, it is proposed that gE and gI, which have such sequences, serve as navigator glycoproteins, forming complexes that direct the signal-deficient glycoproteins to the TGN.

Anterior tibial artery and its actual projection on the lateral aspect of the tibia: a cadaveric study

The anterior tibial artery (ATA) is at risk of injury during high tibial osteotomy, Ilizarov wire placement, pin placement in external fixation, or proximal locking screw insertion, as the artery is not visualized intraoperatively. The ATA is anchored to the oval foramen of the interosseous membrane on the proximal tibia by the deep fascia and recurrent genicular vascular branches. Segment 1 (from the bifurcation of the popliteal artery to the level of the interosseous foramen) and the proximal part of segment 2 (from the interosseous foramen to the level where the artery crosses the anterior border of the tibia) may be damaged when pin, wire or screw placement is directed posterolaterally at that level. Distally, a straight mediolateral pin or Ilizarov wires may lacerate the artery. Segment 2 of the ATA descends against the interosseous membrane in its proximal part, which is projected on the posterior third of the tibia relative to the sagittal plane; in its middle part, it runs close to the lateral cortex of the tibia, it is projected on the middle third of the tibia; in its distal part it runs gradually towards the anterior third of the tibia and contacts with the anterior third of the tibial cortical surface. This information may help reduce risk of injury to the ATA during high tibial osteotomy, external fixation and pin placement or insertion of locking screws.

[Effect of Fusheng powder on activity of vascular endothelial cells and its adhesion to polymorphonuclear neutrophils]

OBJECTIVE

To explore the effect of Fusheng powder on the adhesion of polymorphonuclear neutrophils (PMN) in human peripheral blood to vascular endothelial cells (VEC).

METHODS

Using cultured human umbilical vein cells as target cells, while being incubated with high glucose (HG, 30 mmol/L), high-lipid (HL, 20%), tumor necrosis factor-alpha (TNF-alpha, 10%) and hypoxia (95% N2, 5% CO2, 37 degrees C, 30 min, and then in the air 30 min) for 24 h, respectively, the activity of VEC and the adhesive effect of PMN to VEC were surveyed.

RESULTS

It revealed that HG, HL, TNF-alpha and hypoxia could enhance obviously the adhesion of PMN to VEC, the cell attachment rate in normal control, HG group, TNF-alpha, hypoxia and HL after 30 minutes contact were 100%, 129.6%, 136.7%, 151.4% and 167.7% (all P < 0.01, compared with control group) respectively, but high and low dosage of the Fusheng powder could significantly inhibit the adhesion of PMN to VEC.

CONCLUSIONS

HG, HL, TNF-alpha and hypoxia could all activate EC respectively and enhance the adhesion of PMN to VEC, but the Fusheng powder could protect VEC and partly block the effect of this adhesion. However, the effects of Fusheng powder on anti-adhesion are of great importance in clinical cardiovascular and cerebral vascular diseases.

[The clinical value of intraoperative ultrasound of the liver]

OBJECTIVE

To evaluate usefulness of intraoperative ultrasound of the liver.

METHODS

A 5.0 MHz ultrasound transducer was used to detect liver lesions, their number, location and relation to the intrahepatic blood vessels.

RESULTS

Forty two patients with primary liver tumors received intraoperative ultrasonographic examination. Liver tumor was resected in 29 patients(69.0%). The tumors in 4 patients were unresectable due to their close relationship to the hepatic vasculature as judged by the ultrasound image. Multiple lesions were found in 6 patients during operation.

CONCLUSIONS

Intraoperative ultrasound of the liver is sensitive enough to detect most liver lesions and to locate them by liver segment which makes radical tumor resection possible. It is useful to define the tumor in relation to hepatic vasculature. It can compensate for missing lesions in preoperative imaging studies. Fenestration operation for liver abscess and intervention treatment for liver cysts can be performed during operation.

[Two-phase dynamic CT findings of gastric carcinoma and its value for tumor detection and gross classification]

OBJECTIVE

To analyze the two-phase dynamic CT features of gastric carcinoma and to assess its usefulness for tumor detection and gross classification.

METHODS

Two-phase dynamic CT was performed in 63 cases of gastric carcinoma proved histologically by fibro-gastroscopic biopsy. CT features of gastric carcinoma, tumor detection, and gross classification were correlated with surgical and pathologic findings.

RESULTS

The detectability by two-phase enhanced CT scanning of early and advanced gastric carcinoma was 100% and 98.2%, respectively. The overall accuracy of gross classification for advanced carcinoma was 65.4%, but for early gastric carcinoma, it was 0. The accuracy of Borrmann type II, III, IV was 85.7%, 100%, 55.6%, respectively. In the first phase (early enhancing phase) CT scan, the manifestation of early gastric carcinoma included local thickening of gastric wall, moderate or marked heterogeneous enhancement of lesions in 4 cases and mild enhancement in the other 4 cases. Local or extensive thickening of gastric wall, with or without ulceration, moderate or marked heterogeneous enhancement in early enhancing phase were shown in advanced gastric carcinoma. In the second phase, the degree of tumor enhancement in advanced carcinoma was slightly higher than that of the normal part of gastric wall. There were 4 cases with mucinous adenocarcinoma, a target or laminary appearance was present in 3 cases, and intramural calcification was present in 2 cases.

CONCLUSION

1. Enhanced dynamic CT scan plays a significant role in the diagnosis of gastric carcinoma, early enhancing phase scanning is the technique of choice nowadays for demonstrating tumor lesions. 2. Sophisticated scanning technique is mandatory in improving the diagnostic accuracy of gastric carcinoma.

Human BAG-1/RAP46 protein is generated as four isoforms by alternative translation initiation and overexpressed in cancer cells

Previously, a Bcl-2-interacting protein, BAG-1, was cloned from mouse cells and was shown to interact with several other proteins and to be important for inhibition of apoptosis. Human BAG-1 (hBAG-1) cDNA, recently isolated by us and two other groups, has been shown to be identical to a hormone receptor-binding protein, RAP46. However, different molecular masses of hBAG-1 protein products were noted by these three groups. Here we demonstrated that hBAG-1 protein was expressed as four isoforms, designated p50, p46, p33 and p29, with apparent molecular masses of 50 kDa, 46 kDa, 33 kDa and 29 kDa, respectively. Deletion, site-directed mutagenesis and in vitro transcription/translation analysis showed that the four protein products of hBAG-1 were expressed by alternative initiation from four different start codons through a leaky scanning mechanism. Furthermore, we demonstrated that the distinct forms of hBAG-1 have different subcellular localizations, suggesting that they may have distinct functions in the cells. Characterization of hBAG-1 RNA and protein also showed that hBAG-1 was overexpressed in human cervical, breast and lung cancer cell lines. Taken together, these data clarify the conflicting observations reported in the literature and suggest that hBAG-1 is expressed as four forms of protein products, which may play a differential role in apoptosis and oncogenesis of human cells.

Asymmetry of the mean-variability tradeoff raises questions about the model in investigations of individual bioequivalence

Tradeoff between changes of intraindividual variations of 2 drug formulations and of the difference between their means is a characteristic of a procedure suggested for the determination of individual bioequivalence [Schall and Luus 1993] and to be proposed by the Food and Drug Administration for adoption. Hauck et al. [1996] investigated properties of the tradeoff. Their procedure was applied and extended in the present study. The tradeoff was shown to be asymmetric. Notably, a small change in intrasubject variations can elicit, under various conditions, a comparatively large change in the allowable difference between means which can still be compatible with the declaration of bioequivalence. For instance, when the intraindividual coefficients of variations are 40% and 38% for the reference and test formulations, respectively, the allowable difference between means may increase, as a benefit, by 12.3%. A penalty by 11.2% is elicited if the intrasubject variations of the reference and test products are 40 and 42%, respectively. In addition, 4-period crossover trials were simulated. Ratios of estimated variances of the 2 formulations followed an F-distribution. Distributions of changes in allowable deviations between means were calculated from the tradeoff relationships; generally substantial changes were noted with high probabilities. For example, with an intraindividual variation of 30% there is an estimated 37% probability that a benefit of 10% increase, or larger, is gained by chance in the allowable difference between means, and an additional 36% probability that a penalty of a 10%, or larger, decrease in the allowable difference is suffered. With an intrasubject variation of 40%, the estimated probabilities are 42% and an additional 42% for a 10% expansion and contraction, respectively, of the allowable difference between means. Consequently, the strong asymmetry of the tradeoff could result in very large probabilities for benefits and penalties. Therefore, the investigated model assessing individual bioequivalence does not appear to be suitable for implementation.

Structural models of the transmembrane region of voltage-gated and other K+ channels in open, closed, and inactivated conformations

A large collaborative, multidisciplinary effort involving many research laboratories continues which uses indirect methods of molecular biology and membrane biophysics to analyze the three-dimensional structures and functional mechanisms of K+ channels. This work also extends to the distant relatives of these channels, including the voltage-gated Na+ and Ca2+ channels. The role that our group plays in this process is to combine the information gained from experimental studies with molecular modeling techniques to generate atomic-scale structural models of these proteins. The modeling process involves three stages which are summarized as: (I) prediction of the channel sequence transmembrane topology, including the functionality and secondary structure of the segments; (II) prediction of the relative positions of the transmembrane segments, and (III) filling in all atoms of the amino acid residues, with conformations for energetically stabilized interactions. Both physiochemical and evolutionary principles (including sequence homology analysis) are used to guide the development. In addition to testing the steric and energetic feasibilities of different structural hypotheses, the models provide guidance for the design of new experiments. Structural modeling also serves to "fill in the gaps" of experimental data, such as predicting additional residue interactions and conformational changes responsible for functional processes. The modeling process is currently at the stage that experimental studies have definitely confirmed most of our earlier predictions about the transmembrane topology and functionality of different segments. Additionally, this report describes the detailed, three-dimensional models we have developed for the entire transmembrane region and important functional sites of the voltage-gated Shaker K+ channel in the open, closed, and inactivated conformations (including the ion-selective pore and voltage-sensor regions). As part of this effort, we also describe how our development of structural models for many of the other major K+ channel families aids in determining common structural motifs. As an example, we also present a detailed model of the smaller, bacterial K+ channel from Streptomyces lividans. Finally, we discuss strategies for using newly developed experimental methods for determining the structures and analyzing the functions of these channel proteins.

Enhanced expression of anti-apoptotic proteins in human papillomavirus-immortalized and cigarette smoke condensate-transformed human endocervical cells: correlation with resistance to apoptosis induced by DNA damage

Apoptosis plays an important role in various biological processes including embryogenesis, differentiation, homeostasis, and oncogenesis. We have developed a system composed of primary human endocervical cells (HEN), HEN immortalized by human papillomavirus (HPV) type 16, and their counterparts subsequently malignantly transformed by cigarette smoke condensate (CSC). To understand the role of apoptosis in the multistep oncogenesis of human cervical cells, we examined the expression of apoptosis-associated proteins in our in vitro model system. The results showed no significant difference in the levels of apoptosis-inducing proteins bak and bax among all the cell types examined. On the other hand, the levels of apoptosis-inhibiting proteins bcl-2, bcl-xL and BAG-1 increased progressively after immortalization and transformation. The p53 protein level decreased in the HPV16-immortalized HEN and increased in one of two lines of the CSC-transformed HEN. Further, the increased levels of apoptosis-inhibiting proteins in the HPV16-immortalized and the CSC-transformed HEN correlated with progressively increased resistance of these cells to apoptosis induced by staurosporine or cisplatin. This study provided the first evidence that overexpression of apoptosis-inhibiting proteins is important for both multistep oncogenesis and resistance of human endocervical cells to apoptosis induced by DNA-damaging reagents.

[Effects of Yunqitang on both esophageal mucosal morphology and esophageal motility in reflux esophagitis patients]

OBJECTIVE

To observe the effects of Yunqitang (YQT) on both esophageal mucosal morphology and esophageal motility in patients with reflux esophagitis (RE).

METHODS

According to Syndrome Differentiation of TCM, 42 RE patients were divided into three groups: Disharmony of Liver and Stomach (D) group, Deficiency-Cold of Spleen and Stomach (DC) group, Heat Syndrome caused by depression of Liver Qi (H) group. No. I, II, III of YQT were taken respectively for 4 weeks. Before and after treatment scores of typical symptoms were collected, gastroscope and esophageal motility were measured.

RESULTS

(1) The symptom remission rate was 81.1%, there were significant differences between the group DC with group D and Group H (P < 0.01). (2) The esophageal mucosal healing rate was 61.9%, the effective rate was 90.5%, and the ineffective rate 9.5%. There weren't significant difference of effective rates among the three groups (P < 0.05). (3) The changes of esophageal motility: lower esophageal sphictor pressure (LESP), average peristaltic pressure (APP) of group D were higher (P < 0.05), LESP, gastro-esophageal barrier pressure (GEBP) and peristaltic conduct speed (PCS) of group DC were remarkably higher (P < 0.05), GEBP of group H was improved (P < 0.05).

CONCLUSIONS

YQT has a good therapeutical effect, it's not only resolving reflux symptoms, healing esophageal mucosa, but also improving esophageal motile function.

[Study on expression of Evi1 and MDS1-Evi1 genes in myelodysplastic syndromes]

OBJECTIVE

To investigate expression of Evi1 and MDS1-Evi1 genes in myelodysplastic syndromes (MDS) and its role in pathogenesis of MDS.

METHODS

Expression of Evi1 and MDS1-Evi1 genes was examined in 31 MDS, 11 post MDS acute myeloid leukemia (post MDS AML) and 34 de novo AML patients by a semi-quantitative RT-PCR.

RESULTS

Evi1 expression was not detected in 8 normal controls, but low MDS1-Evi1 expression levels (MDS1-Evi1/GAPDH < 0.1) detected in 3 of the 8 controls. Evi1 mRNA was expressed in 1 of 8 RA, 8 of 13 RAEB and 6 of 9 RAEB-t patients, and the percentage of Evi1 expression in RAEB(t) patients was higher than that in RA(P < 0.05). MDS1-Evi1 expression was detected in 5 of 8 RA, 9 of 13 RAEB and 5 of 9 RAEB-t patients, and MDS1-Evi1 expression levels (MDS1-Evi1/GAPDH > 0.1) in the patients were markedly higher than those in the controls. Evi1 expression was gradually increased in 4 of 5 RAEB-t patients with transformation from MDS to AML. The percentages of Evi-1 and MDS1-Evi1 expression in post MDS AML patients were higher than those in de novo AML (P < 0.01 and P < 0.05, respectively). The numbers of colony formation of progenitor cells in Evi1 and MDS1-Evi1-positive MDS patients were decreased as compared with Evi1 and MDS1-Evi1-negative patients.

CONCLUSION

Abnormal expression of Evi1 and overexpression of MDS1-Evi1 might play a certain role in the pathogenesis or progression of MDS and post MDS AML.

Rhodopsin transgenic pigs as a model for human retinitis pigmentosa

PURPOSE

To further characterize the retinas of Pro3471Leu rhodopsin transgenic pigs, a model for human retinitis pigmentosa.

METHODS

Retinas from normal and transgenic pigs, newborn to 20 months old, were processed for light and electron microscopic immunocytochemical examination.

RESULTS

At birth, rod numbers were normal in the transgenic retinas, but their outer segments were short and disorganized and their inner segments contained stacks of rhodopsin-positive membranes. The newborn rod synapses lacked synaptic vesicles and ribbons and had numerous rhodopsin-positive, filopodia-like processes that extended past the cone synapses into the outer plexiform layer. Rod cell death was apparent by 2 weeks and was pronounced in the mid periphery and central regions by 6 weeks. Far peripheral rods were initially better preserved, but by 9 months virtually all rods had degenerated. Cones degenerated more slowly than rods, but by 4 weeks the cone synapses were shrunken and some mid peripheral cones had lost their immunoreactivity for phosphodiesterase-gamma, arrestin, and recoverin. From 9 months to 20 months, the cone outer segments shortened progressively, and more cones lost immunoreactivity for these proteins.

CONCLUSIONS

The rhodopsin transgenic pig retina shares many cytologic features with human retinas with retinitis pigmentosa and provides an opportunity to examine the earliest stages in photoreceptor degeneration, about which little is known in humans. The finding of abnormal rhodopsin localization in newborn rods is consistent with misrouting of mutant rhodopsin as an early process leading to rod cell death. Novel changes in the photoreceptor synapses may correlate with early electrophysiological abnormalities in these retinas.

Treatment of locally recurrent rectal carcinoma--results and prognostic factors

PURPOSE

To assess the local control and survival in patients who received pelvic irradiation for locally recurrent rectal carcinoma.

METHODS AND MATERIALS

The records of 519 patients with locally recurrent rectal carcinoma treated principally with external-beam radiation therapy between 1975 to 1985 at a single institute were retrospectively reviewed. These included 326 patients who relapsed locally following previous abdominoperineal resection, 151 after previous low anterior resection, and 42 after previous local excision or electrocoagulation for the primary. No patients had received adjuvant radiation therapy or chemotherapy for the primary disease. Concurrent extrapelvic distant metastases were found in 164 (32%) patients at local recurrence and, in the remaining 355, the relapse was confined to the pelvis. There were 290 men and 229 women whose age ranged from 23 to 91 years (median = 65). Median time from initial surgery to radiation therapy for local recurrence was 18 months (3-138 months). Radiation therapy was given with varying dose-fractionation schedules, total doses ranging from 4.4 to 65.0 Gy (median = 30 Gy) over 1 to 92 days (median = 22 days). For 214 patients who received a total dose > or = 35 Gy, radiation therapy was given in 1.8 to 2.5 Gy daily fractions.

RESULTS

The median survival was 14 months and the median time to local disease progression was 5 months from date of pelvic irradiation. The 5-year survival was 5%, and the pelvic disease progression-free rate was 7%. Twelve patients remained alive and free of disease at 5 years after pelvic irradiation. Upon multivariate analysis, overall survival was positively correlated with ECOG performance status (p = 0.0001), absence of extrapelvic metastases (p = 0.0001), long intervals from initial surgery to radiation therapy for local recurrence (p = 0.0001), total radiation dose (p = 0.0001), and absence of obstructive uropathy (p = 0.0013). Pelvic disease progression-free rates were positively correlated with ECOG performance status (p = 0.0001), total radiation dose (p = 0.0001), and previous conservative surgery for the primary (p = 0.02).

CONCLUSIONS

Survival is poor for patients who develop local recurrence following previous surgery for rectal carcinoma. Pelvic radiation therapy provides only short-term palliation, and future efforts should be directed to the use of effective adjuvant therapy for patients with rectal carcinoma who are at high risk of local recurrence.

The role of ras gene mutation in gastric cancer and precancerous lesions

Abnormality of ras gene family was studied in a total of 206 cases of gastric cancer and precancerous lesions by PCR-RFLP, PCR-SSCP and DNA sequencing. The results showed that mutation rate of H-ras 12 codon in metaplasia, atypical hyperplasia, early-stage cancer and advanced cancer was 16.7%, 31.2%, 50.0%, and 32.2%, respectively. In the groups of superficial gastritis and normal controls, no mutation were detected in codon 12 of ras. Mutations of H-ras 61 codon and N-ras 12 codon in various groups were the same as those in normal control. K-ras 12 codon mutation was detected in only 2 cases of gastric cancer by using PCR-SSCP, but it was not detected by DNA sequencing, which may be polymorphism. All H-ras 12 codon mutations were G-->T mutation. There were significant difference between the groups of metaplasia, dysplasia, gastric carcinoma and normal control group (P < 0.05, P < 0.01, P < 0.01, respectively). It was concluded that H-ras 12 codon mutation was an early event and may play an important role in gastric carcinogenesis. Although K-ras, N-ras mutation rates are high in colon cancer and leukemia, it seems to bear no relationship with gastric cancer.

Immunophenotype of myeloid cells in myelodysplastic syndromes and its clinical implications

OBJECTIVE

To explore the immunophenotype of myeloid cells in myelodysplastic syndyomes (MDS) and its clinical implications.

METHODS

A panel of monoclonal antibody was used to detect CD13+, CD33+, CD15+ and CD14+ antigens on the membrane surfaces of myeloid cells in the bone marrow from 51 MDS, 21 aplastic anemia (AA), 21 paroxysmal nocturnal hemoglobinuria (PNH) patients. 10 acute myeloblastic leukemia (AML) patients and 15 normal subjects by immunoenzymatic assay. The morphology and chromosome karyotype of bone marrow cells of MDS patients were also examined.

RESULTS

CD14+, CD13+ and CD33+ cells in the bone marrow were more in MDS patients than in normal controls, AA patients and PNH patients. CD15+ cells in the bone marrow were less in MDS patients than in normal controls.

CONCLUSIONS

The percentages of CD14+, CD13+ and CD33+ positive cells in the bone marrow of MDS patients were related to the percentage of myeloblasts, the chromosomal aberrations and the response to treatment. It indicated that there is immunophenotypic misexpression of myeloid cells in MDS patients. Immunophenotype analysis of myeloid cells might be useful for the diagnosis and treatment of MDS patients.

[Study on T lymphocyte recognition of tumor antigens on autologous CML cells]

OBJECTIVE

To investigate the existence of cytotoxic precursor cells in previously untreated or remissive chronic myelogenous leukemia(CML) patients,and identify their phenotypical and functional characteristics.

METHODS

Bone marrow or peripheral blood mononuclear cells from CML patients were stimulated with autologous CML cells by using mixed lymphocyte tumor cell coculture.

RESULTS

A kind of cytotoxic T lymphocytes could be generated from bone marrow or peripheral blood of CML patients. These T cells showed differential cytotoxicities against autologous and allogeneic CML cells and no activity to autologous and allogeneic normal bone marrow cells. They also exhibited no inhibitive effect on CFU-GM yields. LAK cells had no effect on autologous CML cells, but showed intensive cytotoxic activity to allogeneic CML cells. The T lymphocytes obtained were CD3+ CD56+ non-MHC restricted or CD3+ CD56- MHC restricted. HLA-DR and CD25 were expressed in a significantly larger proportion of T lymphocytes stimulated with autologous CML cells than those not stimulated. The T lymphocytes showed low proliferative response to autologous CML cell stimulation and no or least response to allogeneic CML cells, they showed also no response to EB virus-transformed autologous B cells(obtained in remission) pulsed with peptides corresponding to the BCR-ABL joining region.

CONCLUSION

There is probably a common tumor antigen among CMLs, this leukemia-specific antigen can be recognized by T cells,and it shows no indication to be a p210 fusion sequence.

Interobserver variation in prostate cancer Gleason scoring: are there implications for the design of clinical trials and treatment strategies?

A series of prostate cancer histological slides from 71 patients were used to measure the interobserver variation among three pathologists awarding a Gleason score. The study was prompted on account of the use of histological grade to stratify patients prior to randomization within two clinical trials currently recruiting at our centre, and a proposed study that would allocate treatment depending upon the score awarded. The pathologists were expected to award a score based upon their day to day experience, there being no consensus meeting before-hand to agree on the grey areas of the Gleason grading system. We used the kappa statistic to assess the level of agreement. This was calculated both for comparison of the raw scores awarded by the three observers, as well as the grouped scores corresponding to those groupings used for the purposes of stratification in the two trials. The extent of the interobserver variation (weighted kappa) for the raw scores (Gleason scores 2-10) was 0.16 to 0.29 and for the grouped scores (Gleason scores < or = 7 or > or = 8), kappa was 0.15 to 0.29. For the raw scores, the total agreement rate was 9.9% and the total disagreement 26.8%; for the grouped scores the total agreement rate was 43.7%. It is concluded that, despite this level of agreement there is no concern regarding stratification using the Gleason score, because of the subsequent randomization. However, using a reported Gleason score to determine treatment might be inappropriate. These data indicate the value of a central review process for pathology grading in clinical trials, especially where the treatment is directly affected by this information.

Predicting the outcome of postasphyxial hypoxic-ischemic encephalopathy within 4 hours of birth

OBJECTIVE

To build models that predict severe adverse outcome within 4 hours of birth in patients with postasphyxial hypoxic-ischemic encephalopathy. The goal was to develop models for selecting patients for therapeutic trials of neuroprotective medications.

STUDY DESIGN

Retrospective cohort study with follow-up to a minimum age of 12 months of 164 "outborn" term infants admitted to a tertiary neonatal intensive care unit, and 14 "inborn" term infants in the two tertiary perinatal centers in a regionalized setting. After performing univariate screening tests, multivariate models of association between risk factors and "severe adverse outcome" (death or major neurosensory impairment) were constructed.

RESULTS

Of 178 infants with postasphyxial hypoxic-ischemic encephalopathy of defined severity admitted consecutively between 1985 and 1992, 48 died, 40 survived with major neurosensory impairment, and 13 were lost to follow-up. The important predictors of severe adverse outcome in the first 4 hours were delayed onset of breathing, administration of chest compressions, and seizures. At 60 minutes of age, based on predicted probabilities of > 0.50, the sensitivity of the predictive model was 85% and specificity 68%. The parameter estimates of the predictive models are reported.

CONCLUSIONS

Age of onset of breathing, administration of chest compressions, and age of onset of seizures were the most important variables predictive of adverse outcome in this study. Although fairly sensitive and specific, these predictive models should be applied with caution. To build more accurate models, a template for the conduct of a large, multicenter prospective study is provided.

Molecular dynamics study of free energy profiles for organic cations in gramicidin A channels

The free energy profiles for four organic cations in right-handed single-helix gramicidin A dimers were computed by using umbrella sampling molecular dynamics with CHARMM. Ion-water column translocations were facilitated by using a novel "water-tunnel" approach. The overlapping pieces of free energy profile for adjacent windows were selected from three trajectories that differed in initial ion rotation and were aligned by the method of umbrella potential differences. Neglected long-range electrostatic energies from the bulk water and the bilayer were computed with DelPhi and added to the profile. The approach was corroborated for the formamidinium-guanidinium pair by using perturbation dynamics at axial positions 0, 6, 12, and 15 A from the channel center. The barrier to ethylammonium entry was prohibitive at 21 kcal/mol, whereas for methylammonium it was 5.5 kcal/mol, and the profile was quite flat through the channel, roughly consistent with conductance measurements. The profile for formamidinium was very similar to that of methylammonium. Guanidinium had a high entry barrier (deltaF = +8.6 kcal/mol) and a narrow deep central well (deltaF = -2.6 kcal/mol), qualitatively consistent with predictions from voltage-dependent potassium current block measurements. Its deep central well, contrasting with the flat profile for formamidinium, was verified with perturbation dynamics and was correlated with its high propensity to form hydrogen bonds with the channel at the dimer junction (not shared by the other three cations). Analysis of the ensemble average radial forces on the ions demonstrates that all four ions undergo compressive forces in the channel that are at maximum at the center of the monomer and relieved at the dimer junction, illustrating increased flexibility of the channel walls in the center of the channel.

Genetically engineered large animal model for studying cone photoreceptor survival and degeneration in retinitis pigmentosa

Patients with retinitis pigmentosa (RP) typically develop night blindness early in life due to loss of rod photoreceptors. The remaining cone photoreceptors are the mainstay of their vision; however, over years or decades, these cones slowly degenerate, leading to blindness. We created transgenic pigs that express a mutated rhodopsin gene (Pro347Leu). Like RP patients with the same mutation, these pigs have early and severe rod loss; initially their cones are relatively spared, but these surviving cones slowly degenerate. By age 20 months, there is only a single layer of morphologically abnormal cones and the cone electroretinogram is markedly reduced. Given the strong similarities in phenotype to that of RP patients, these transgenic pigs will provide a large animal model for study of the protracted phase of cone degeneration found in RP and for preclinical treatment trials.

Improvement in total positioning error for lateral prostatic fields using a soft immobilization device

PURPOSE

To prospectively measure the total positioning error present in lateral pelvic fields of patients undergoing prostatic irradiation, and to evaluate the effect of a rigid table insert and soft immobilization on the magnitude of the measured error.

MATERIALS AND METHODS

Sixty-one consecutive patients receiving radical prostatic irradiation with a four field technique underwent a total of 234 lateral portal films during the first, third, fifth and seventh week of treatment. The position of the isocentre was compared to the isocentre on the corresponding simulator films and the magnitude and direction of deviations recorded. The patients were divided in to three cohorts of 15 patients, 15 patients and 31 patients. The first cohort was treated on a standard treatment couch, the second cohort treated with the table top stiffened using a 1 cm polycarbonate insert, and the third cohort treated with a soft immobilization device supporting the lower legs, and the polycarbonate insert.

RESULTS

There was no difference in the mean deviation of the vector of the isocentre displacement in the y and z directions identified at any of the four times when measurements were taken during therapy between the cohorts treated with or without the polycarbonate insert, but without immobilization. The overall mean deviation for these first two cohorts of patients was 3.9 mm. The positioning of patients treated with immobilization was compared to those treated without, and the immobilized patients had a significantly improved overall mean deviation of 2.6 mm (P = 0.002). This was a result of improvement in both the random and systematic components of the total error. In addition, the proportion of errors greater than 5 mm was reduced from 17% of set-ups to 8% of set-ups. The time during the course of treatment when the measurement was taken had no effect on positioning error for any of the treatment groups.

CONCLUSION

Stiffening the treatment couch with a 1 cm thick polycarbonate insert had no effect on reducing total positioning error, but immobilization with an inexpensive and non-customized foam rubber leg support reduced total positioning error in a statistically significant way.

[Detection of ras gene mutation in various stages of gastric cancer by PCR/RFLP SSCP and DNA sequencing]

Investigate mutation of ras gene family in various stage of gastric cancer in China. PCR-RFLP, PCR-SSCP and PCR-DNA sequencing were used to detect mutation rates of H-ras, K-ras and N-ras gene. Mutation rates of H-ras at 12 codon in metaplasia, atypical hyperplasia, and progressive gastric cancer is 16.7% (6/36), 31.2% (15/48), 34.7% (25/72), respectively. In groups of superficial gastritis and normal control, no mutation were found. Mutations of H-ras 61 codon and N-ras 12 codon in various groups were the same as normal. Only 2 cases of K-ras 12 codon mutation were detected in gastric cancer by PCR-SSCP, but it was not identified by DNA sequencing. It may be of polymorphism. All H-ras 12 codon mutation were G-->T mutation. There are significant difference between groups of metaplasia, dysplasia, and gastric carcinoma comparing with group of normal control (P < 0.05, P < 0.01, P < 0.01). H-ras 12 codon mutation maybe an early event and maybe play important role in gastric carcinogenesis. Although K-ras mutation rate is high in colon cancer and leukemia it seemed to be relationship with gastric cancer. High frequency of H-ras 12 codon mutation maybe the characteristic of gastric cancer and associate with high incidence of gastric cancer in China. Three methods used in this experiment were compared that SSCP method is more sensitive than RFLP and cold SSCP is simpler and likely to be used in clinic.

High-affinity CCK-A receptors on the vagus nerve mediate CCK-stimulated pancreatic secretion in rats

Cholecystokinin (CCK) receptors are found on vagal afferent fibers. In pancreatic acini, CCK receptors exist in high- and low-affinity states. The aim of this study was to identify the vagal CCK-A receptor affinity state that mediates the effect of CCK on pancreatic protein secretion. Using a rat model with a pancreatic-biliary cannula, we studied the effects of CCK-JMV-180 on exocrine pancreatic function. CCK-JMV-180 acts as an agonist on high-affinity CCK receptors and as an antagonist on low-affinity CCK receptors. Infusion of CCK-JMV-180 (22-88 micrograms.kg-1.h-1) caused dose-dependent increases in pancreatic protein secretion, which were blocked by the CCK-A receptor antagonist L-364,718. Acute vagotomy in anesthetized rats and perivagal application of capsaicin in conscious rats abolished pancreatic responses to CCK-JMV-180 at 22 and 44 micrograms.kg-1.h-1. CCK-JMV-180 did not reduce pancreatic responses to CCK octapeptide infusion at 20 and 40 pmol.kg-1.h-1. To demonstrate that endogenously released CCK also acts on high-affinity CCK-A receptors, we showed that in conscious rats intraduodenal infusion of 18% casein produced a threefold increase in protein secretion and elevated plasma CCK levels from 0.7 to 8.4 pM. Infusion of CCK-JMV-180 at 44 micrograms.kg-1.h-1 failed to inhibit pancreatic responses to casein. In separate studies, perivagal application of 1% capsaicin inhibited 95% and 90% of the pancreatic responses to casein and casein combined with intravenous CCK-JMV-180, respectively. The neurotoxic effect of capsaicin on small-diameter sensory vagal fibers was verified by immunohistochemical and retrograde tracing studies. In conclusion, we demonstrated that in contrast to their effect on satiety, which is mediated by vagal low-affinity CCK-A receptors, exogenous CCK and endogenous CCK under physiological conditions act through high-affinity CCK-A receptors to mediate pancreatic protein secretion. These findings suggest that different affinity states of the vagal CCK receptors mediate different digestive functions.

[The killing effect of IL-2 and IFN-alpha activated bone marrow on K562 leukemic cell]

OBJECTIVE

To evaluate the killing effect of IL-2 and IFN-alpha activated bone marrow cells on K562 cells.

METHODS

Semi-solid colony assay was used.

RESULTS

Bone marrow from leukemia patients in remission was activated in vitro with IL-2 for 3 days. The activated bone marrow (ABM) displayed killing effects of 0.31 approximately 2.30 logs on K562 cells, this killing effects was further increased to 0. 30 approximately > 3.15 logs when IFN-alpha added with IL-2 to the marrow for activation. IL-2 alone or in combination with IFN-alpha showed no inhibition of CFU-GM and K562 cells. Compared with IL-2 or IFN-alpha alone, the combination of the two cytokines could more effectively maintain the killing effect of ABM on leukemic cells.

CONCLUSION

IFN-alpha can augment the purging effect of IL-2 ABM and combination of the two cytokines can effectively maintain the cytotoxicity of ABM.

[Effects of IFN-alpha on the expressions of perforin and granzymes in IL-2 activated lymphocytes]

OBJECTIVE

To study the effect of IFN-alpha on the expressions of perforin and granzymes in IL-2-activated-lymphocytes.

METHODS

NK and LAK activities were assayed by 4 hour standard 51Cr release test, the activity of perforin was detected by hemolysis method, expression of granzyme B was measured by ABC immunohistological method, expression of granzyme A was measured by BLT method.

RESULTS

IFN-alpha significantly augmented the activities of NK and LAK in IL-2 activated peripheral blood lymphocytes (PBL) after 1 day culture. Perforin activity in lymphocytes was increased after 1 day exposure to IL-2 or IFN-alpha, and was enhanced when exposed to the combination of IL-2 and IFN-alpha. After 3 day culture, the perforin activity remained high in lymphocytes activated by IL-2 alone or in combination with IFN-alpha, while declined to control level in IFN-alpha exposed group. IL-2 and IFN-alpha alone or in combination had no effect on expression of granzyme A and B.

CONCLUSION

IFN-alpha enhances the cytotoxicity of lymphocytes activated by IL-2. The mechanism might be that IFN-alpha upregulates the perforin expression.

Quality of life following bone marrow transplantation: a comparison of patient reports with population norms

All surviving patients who had received an allogeneic bone marrow transplant at the Princess Margaret Hospital were asked to participate in a health-related quality of life (HQL) study using the Medical Outcomes Survey-Short Form 36 (MOS SF-36), the Satisfaction with Life Domains Scale-Bone Marrow Transplantation (SLDS-BMT) and a current symptoms checklist. The main objective was to compare the health status of BMT survivors with age-adjusted population norms. Of the 251 patients contacted, 93% returned questionnaires. The median follow-up after BMT was 40 months, ranging from 1-253 months. On average, survivors had some diminished HQL relative to the health status of the population in general. Time since transplant had a significant influence on HQL; those less than 3 years from transplant experienced considerable impairment while those who had survived beyond this point were indistinguishable from the normal population in most domains and significantly better in certain psychosocial aspects of health. Many patients still reported symptoms months after BMT; some were mildly affected while others experienced more troublesome symptoms. However, 81% of patients were satisfied with the HQL outcome that they had achieved and 94% would recommend a transplant for someone in similar circumstances.

Anatomic considerations of the lumbar isthmus

STUDY DESIGN

A morphometric study of lumbar isthmus from L1 to L5 on 30 dried lumbar spines was conducted.

OBJECTIVE

To provide anatomic data about the lumbar isthmus and to quantitatively evaluate structural features of the lumbar isthmus and its relationship to adjacent anatomic structures.

SUMMARY OF BACKGROUND DATA

There are very few anatomic studies about the lumbar isthmus, and no study describes the relationship of the lumbar isthmus to its adjacent structures.

METHODS

Direct measurements using digital calipers and a goniometer were taken from 30 dried lumbar spines. Anatomic evaluation focused on the lumbar isthmus and its related structures, the isthmus pedicle, and superior and inferior facets. Seven linear and four angular parameters of the lumbar isthmus were determined.

RESULTS

The length of the superior edge of the isthmus gradually increased from L2 to L5 (from 8.22 +/- 1.43 mm at L2 to 10.44 +/- 1.90 mm at L5), and that of its inferior edge progressively decreased from L2 to L5 (from 8.67 +/- 1.76 mm at L2 to 6.34 +/- 1.74 mm at L5). The superoinferior diameter of the isthmus decreased from L3 to L5 (from 13.87 +/- 1.77 mm at L3 to 13.26 +/- 2.49 mm at L5). The superior edge of the isthmus was the thinnest at L4 (1.62 +/- 0.58 mm), and its thickness inferiorly increased from L1 to L5 (from 6.71 +/- 1.47 mm at L1 to 7.76 +/- 1.08 mm at L5). The medial and caudal inclination of the isthmus with respect to the pedicle gradually increased from L1 to L5 (from 112.3 degrees +/- 13.8 degrees at L1 to 119.2 degrees +/- 11.2 degrees at L5 medial inclination and from 132.5 degrees +/- 8.8 degrees at L2 to 139.0 degrees +/- 12.1 degrees at L5 caudal inclination, respectively). The dimensions of the lumbar isthmus were positively correlated to dimensions of the pedicle and orientations of the facets.

CONCLUSIONS

This study provides detailed anatomic data of the lumbar isthmus. Anatomic parameters of the lumbar isthmus are related to the vertebral levels and have a significant correlation with the angles of the facets and the dimensions of the pedicles. The vulnerability of the pars interarticularis of the fifth lumbar vertebra has been anatomically confirmed.

[Clonal analysis of blood cells using X-linked HUMARA gene polymorphism]

OBJECTIVE

To explore the method for clonal analysis of blood cells.

METHODS

Thirty female AML patients and 20 normal female subjects were analysed by the analysis of X-linked HUMARA gene polymorphism and methylation pattern.

RESULTS

The heterozygote rate of HUMARA gene in Chinese women was 88% and the gene had a stable methylation pattern. Out of 20 control females, 17 were heterozygotes and among them 15 were polyclonal, 2 (11.8%) showed skewed X-inactivation. All heterozygote AML were clonal hematopoiesis.

CONCLUSION

HUMARA gene polymorphism is a good marker for clonality analysis of blood cells.

Lack of influence of sequence of top-up doses on repair kinetics in rat spinal cord

BACKGROUND AND PURPOSE

The rat spinal cord model was used to determine whether repair kinetics changed during a course of fractionated radiotherapy if twice daily doses were given either at the initial or final period of a concomitant boost irradiation schedule.

MATERIALS AND METHODS

The rat cervical spinal cord was irradiated from C2-T2 in 870 animals with top-up doses of three daily fractions of 9 Gy representing 75% of the biologic dose at the ED50 level for white matter necrosis. To simulate concomitant boost protocols, these top-up doses were given either preceding (initial top-up) or following (final top-up) a b.i.d. schedule of 1 Gy/F delivered at 0, 1, 2, 4, 8 or 24 h interfraction intervals. The end point was forelimb paralysis secondary to white matter necrosis.

RESULTS

For interfraction intervals of 0, 1, 2, 4, 8 and 24 h, the initial top-up schedules yielded ED50 values of 18.2, 19.2, 23.7, 21.3, 27.2 and 29.7 Gy, respectively; the corresponding ED50s from the final top-up schedules were 17.5, 19.0, 20.7, 21.2, 26.9 and 30.3 Gy, respectively. A 10% reduction in the ED50 value from pooled data was observed when the interfraction interval was reduced from 24 (ED50 = 30.3 Gy) to 8 h (ED50 = 27.1 Gy). Fitting the incomplete repair (IR) version of the LQ model with mono-exponential repair kinetics gave alpha/beta values of 1.4 and 1.5 Gy, and similar repair half-times of 4.3 and 5.0 h for the initial and final top-up experiments, respectively. The IR model with bi-exponential repair kinetics did not provide a better fit to the data.

CONCLUSIONS

We conclude that the sequence of top-up doses has no apparent influence on radiation sensitivity or repair kinetics in the rat spinal cord. The clinical implication is that the interfraction interval but not the timing of the boost is a critical determinant of spinal cord tolerance in concomitant boost protocols.

[Study on the immunophenotype of myeloid cells in myelodysplastic syndromes and its clinical implications]

OBJECTIVE

To explore the immunophenotype of myeloid cells in myelodysplastic syndromes and its clinical implications.

METHODS

A panel of monoclonal antibodies was used to detect CD13, CD33, CD15 and CD14 on the membrane surfaces of myeloid cells in the bone marrow from 51 patients with myelodysplastic syndromes (MDS), 21 with aplastic anemia (AA), 21 with paroxysmal nocturnal hemoglobinuria (PNH), and 15 normal subjects, by immunoenzymatic assay. The morphology and chromosome karyotype of bone marrow cells of MDS patients were also examined.

RESULTS

CD14+ cells, CD13+ cells and CD33+ cells in the bone marrow were more in MDS patients than in normal controls, AA patients and PNH patients. CD15+ cells in the bone marrow were less in MDS patients than in normal controls. The percentages of CD14, CD13 and CD33 positive cells in the bone marrow of MDS patients were related to the percentage of myeloblast, the chromosomal aberrations and the response to treatment.

CONCLUSION

There was an immunophenotypic misexpression of myeloid cells in MDS patients. Immunophenotype analysis of myeloid cells might be useful for the diagnosis and directing treatment in MDS patients.

Correlation of DNA fragmentation and chromatin condensation in apoptotic nuclei of the Ser 6 mouse retina

The form of cell death known as apoptosis was first described in thymocytes. The hallmarks of apoptosis include chromatin condensation, membrane blebbing, formation of apoptotic bodies, and DNA fragmentation. DNA fragmentation can be visualized morphologically by the TdT-mediated dUTP-biotin nick end labeling (TUNEL) method that labels the cut DNA ends. However, at the light microscopic (LM) level, TUNEL-positive nuclei cannot readily be correlated with the other hallmarks of apoptosis. In the retina, chromatin condensation and DNA fragmentation are the major features of developmental cell death as well as photoreceptor degeneration. We performed TUNEL at the electron microscopic (EM) level, which permitted correlation of DNA fragmentation with chromatin condensation. We studied the retinas of transgenic mice (Ser 6) expressing the Pro347Ser mutant rhodopsin gene during developmental cell death (age 7 days) and photoreceptor degeneration (age 21 days). We found that 90% of the nuclei showing chromatin condensation were TUNEL positive as well. Our results demonstrated DNA fragmentation and chromatin condensation in the same cells as they underwent apoptosis in vivo, confirming the notion that these processes are concomitant events, and by implication, that activation of an endogenous endonuclease is an important step in the death process of retinal neurons.

A pathologic study of degeneration of the rod and cone populations of the rhodopsin Pro347Leu transgenic pigs

PURPOSE

Transgenic pigs with rhodopsin (Pro347Leu) mutation exhibited rod-cone degeneration. We compared the pathologic characteristics of the rod degeneration versus those of the cone cells.

METHODS

The posterior and peripheral retinas of these transgenic pigs of age 4, 6, 8, 12, 24 and 33 weeks and normal pigs of age 4 and 8 weeks were studied by light and EM and morphometry.

RESULTS

The pathologic changes observed in the posterior and peripheral retinas of the transgenic pigs could be conveniently described in 3 phases: I) an initial phase of rapid and extensive degeneration of the rod cells in the first 6 weeks of age; II) an acute phase of cone cell degeneration involving approximately half of the population and lingering rod degeneration in the 6 to 12 weeks of age; and III) a partial cone recovery to be followed by a chronic degenerative phase of the remaining cones cells from 12 to 33 weeks of age.

CONCLUSION

Our study showed that the degenerative changes of rod cells could be differentiated from those of the cone cells. Cone and rod populations degenerated along different time schedule with different pathologic features. Hence, treatment for retinitis pigmentosa might vary with the different stages of the disease.

Long-term recovery kinetics of radiation damage in rat spinal cord

PURPOSE

This study aimed to assess the influence of the level of initial injury on the long-term recovery kinetics of radiation damage in the central nervous system using a rat spinal cord model.

METHODS AND MATERIALS

The adult rat spinal cord (C2-T2) was initially given two or three daily fractions of 9 Gy, or three daily fractions of 10.25 Gy. At day 4 or weeks 6, 8, 12, 20, 28, 40, or 52, animals were reirradiated with graded single doses of X rays. The end point was forelimb paralysis caused by white-matter necrosis.

RESULTS

Latent times to paralysis as measured from the date of the initial treatment increased with increasing time interval between initial treatment and reirradiation but decreased with increasing size of initial injury. Retreatment ED50s were 14.1, 14.8, 15.4, 16.3, and 16.2 Gy for animals reirradiated at day 4 and weeks 8, 12, 20, and 28, respectively, after an initial dose of 9 Gy x 2. After 9 Gy x 3, the retreatment ED50s at day 4 and weeks 6, 8, 12, 20, 28, 40, and 52 were 10.0, 9.9, 9.8, 12.0, 13.9, 14.6, 14.7, and 15.5 Gy, respectively. For an initial dose of 10.25 Gy x 3, the retreatment ED50s at day 4 and weeks 8, 12, 20, 28, and 40 were 5.8, 6.1, 8.4, 10.6, 12.2, and 13.3 Gy, respectively. Using the linear-quadratic (LQ) model, alpha/beta of 3.0 Gy, to quantitate the biological effect of the different retreatment schedules, the initial doses of 9 Gy x 2 or 3, or 10.25 Gy x 3 were found to represent 47, 71, and 89% of the extrapolated response dose (ERD), respectively, and no significant increase in tolerance was observed for retreatment given within 8 weeks of initial treatment. Significant long-term recovery was observed thereafter and increased with increasing time interval to retreatment. The retreatment tolerance and radiation damage recovered at different intervals were influenced by the initial dose. Using direct analysis, the recovery kinetics could be best described by introducing a time function consisting of a linear and quadratic time component dependent on initial dose to the LQ model.

CONCLUSION

These results are consistent with the presence of significant long-term recovery of radiation damage in rat spinal cord, and suggest that the size of the initial damage influences the recovery kinetics, and hence the retreatment tolerance.

[Preliminary study on oncogene MDM2 in acute leukemias]

OBJECTIVE

To explore the causes of MDM2 gene overexpression.

METHODS

The amplification and overexpression of MDM2 gene in 41 acute leukemia patients and two leukemic cell lines (K051 and HL60) were studied by using Southern blot, dot hybridyzation and RT-PCR techniques.

RESULTS

Overexpression of MDM2 gene was found in 51.2% (21/41) of the patients and HL60 cell line, but no amplification of the gene was found in all the patients and the two cell lines.

CONCLUSION

The level of MDM2 gene expression was related to the prognoses of the patients but not to FAB subtypes of acute leukemias.

Abnormal change of p53 gene in gastric and precancerous lesions and APC gene deletion in gastric carcinoma and near tissues

p53 gene mutation (exon4, 5, 6, 7, 8 and intron6) in gastric cancer and precancerous lesions and p53 gene (exon4 and ontron6), APC gene deletion in gastric carcinomas were studied by PCR/SSCP and PCR/RFLP. Results showed mutation rate of p53 in metaplasia, dysplasia and gastric carcinoma was 37.5% (3/8), 42.17% (8/19), 53.33 (16/30) respectively. There was significant difference among groups of metaplasia, dysplasia, cancer and normal controls. No exon8 mutation was found in metaplasia and dysplasia, but 4 cases were found to have exon8 mutation in cancer group. It is suggested that exon8 mutation occurs at the late stage of gastric cancer, but exon 5, 6, 7 mutation occur in the course of precancerous lesion to cancer. Loss of heterozygosity (LOH) of exon4, intron6, APC was 47, 37% (9/19), 8.73% (2/23), 16.67% (3/18) respectively. LOH of exon4 had something to do with poor differentiation, lymph node metastasis, depth of invasion. LOH of exon4 may be of prognostic marker of gastric cancer. We are led to conclude that p53 gene mutation is an early event and perhaps work together with ras oncogene in gastric carcinogenesis.

Relationship between some humoral factors and left ventricular hypertrophy in essential hypertension

OBJECTIVE

To evaluate the relationship between certain humoral factors and left ventricular hypertrophy (LVH) in essential hypertension.

PATIENTS AND METHODS

62 essential hypertension (EH) patients (32 men, 30 women; mean age, 55 years) and 20 normotensive healthy subjects (10 men, 10 women: mean age, 52 years) were studied. EH patients were divided into LVH group and non-LVH group by echocardiography. After an overnight fast, blood samples were taken for the determination of parathyroid hormone (PTH), angiotensin II (ATII) and aldosterone (ALD) by radioimmunoassay.

RESULTS

There was a significant difference in PTH. AT II and ALD between the EH group and control group. Furthermore, in LVH group PTH, ATII and ALD elevated significantly as compared with non-LVH group. In addition, we found that LVMI (left ventricular mass index) correlated with ATII (r = 0.342, P < 0.01) and ALD (r = 0.356, P < 0.01). There was a more significant correlation between LVMI and PTH (r = 0.422, P < 0.0025).

CONCLUSIONS

Some humoral factors are important determinants of LV mass. Besides the reninangiotensin-aldosterone system, PTH might play an important role in cardiac hypertrophy.

Targeting of glycoprotein I (gE) of varicella-zoster virus to the trans-Golgi network by an AYRV sequence and an acidic amino acid-rich patch in the cytosolic domain of the molecule

Previous studies suggested that varicella-zoster virus (VZV) envelope glycoproteins (gps) are selectively transported to the trans-Golgi network (TGN) and that the cytosolic domain of gpI (gE) targets it to the TGN. To identify targeting signals in the gpI cytosolic domain, intracellular protein trafficking was studied in transfected cells expressing chimeric proteins in which a full-length or mutated gpI cytosolic domain was fused to the gpI transmembrane domain and interleukin-2 receptor (tac) ectodomain. Expressed protein was visualized with antibodies to tac. A targeting sequence (AYRV) and a second, acidic amino acid-rich region of the gpI cytosolic domain (putative signal patch) were each sufficient to cause expressed protein to colocalize with TGN markers. This targeting was lost when the tyrosine of the AYRV sequence was replaced with glycine or lysine, when arginine was replaced with glutamic acid, or when valine was substituted with lysine. In contrast, tyrosine could be replaced by phenylalanine and valine could be substituted with leucine. Mutation of alanine to aspartic acid or deletion of alanine abolished TGN targeting. Exposure of transfected cells to antibodies to the tac ectodomain revealed that the TCN targeting of expressed tac-gpI chimeric proteins occurred as a result of selective retrieval from the plasmalemma. These data suggest that the AYRV sequence and a second signaling patch in the cytosolic domain of gpI are responsible for its targeting to the TGN. The observations also support the hypothesis that the TGN plays a critical role in the envelopment of VZV.

[New flexible open-loop anterior chamber lens in secondary implantation]

OBJECTIVE

To determine the efficacy of new flexible open-loop anterior chamber intraocular lens (AC IOL) in secondary implantation.

METHOD

Secondary AG-IOL implantation in 35 eyes including 28 with traumatic cataract and 7 with senile cataract was performed 3 months to 2.5 years after primary cataract extraction. All patients were followed up for at least 6 months.

RESULTS

Of the 35 eyes, 27 (77.1%) had a final visual acuity of 0.5 or better and 11 (31.4%) had 1.0 or better.

CONCLUSION

New flexible open-loop AC IOL is safe and effective for secondary IOL implantation.

Gadolinium(III) texaphyrin: a tumor selective radiation sensitizer that is detectable by MRI

Gadolinium(III) texaphyrin (Gd-tex2+) is representative of a new class of radiation sensitizers detectable by magnetic resonance imaging (MRI). This porphyrin-like complex has a high electron affinity [E1/2 (red.) approximately = -0.08 V versus normal hydrogen electrode] and forms a long-lived pi-radical cation upon exposure to hydrated electrons, reducing ketyl radicals, or superoxide ions. Consistent with these chemical findings, Gd-tex2+ was found to be an efficient radiation sensitizer in studies carried out with HT29 cells in in vitro as well as in in vivo single and multifraction irradiation studies with a murine mammary carcinoma model. Selective localization of Gd-tex2+ in tumors was confirmed by MRI scanning.

[Promotion of c-fos oncogene expression in cultured rabbit lens epithelial cells by macrophages]

OBJECTIVE

This study was designed to test the hypothesis that inflammatory cells deposited on the surface of implanted intraocular lens stimulate the proliferation of residual lens epithelial cells.

METHODS

Immunocytochemical ABC methods with purified anti-human Fos protein serum antibody was used to stain the cultured rabbit lens epithelial cells incubated with rabbit macrophages and macrophage-conditioned medium (MCM).

RESULTS

The lens epithelial cell growth was faster in the cultures with macrophages and MCM than in the controls. Fos protein positive staining was found in the nuclei of epithelial cells cultured with macrophages for 4 hours, and of the cells with MCM for one hour; whereas the staining was negative in the cells of control cultures.

CONCLUSION

Macrophages promote c-fos oncogene expression in the lens epithelial cells, that might be mediated by bioactive factors secreted by macrophages.

[Changes in hematoporphyrin in patients with gastric and hepatic carcinoma and their clinical significance]

The fluorescence spectroscopy of porphyrin molecule in blood was determined with photoluminescence fluorescence spectroscope in 139 patients with gastric carcinoma, 76 with hepatic carcinoma, 110 with gastric ulcer and chronic gastritis, 168 with liver cirrhosis and 33 normals as controls. The results showed that the peaks of Zinc porphyrin and protoporphyrin in patients with cancer were significantly higher than those in patients with benign disease, the peak of protoporphyrin being two to three times higher in the former groups of patients than that in the latter (P < 0.01). Protoporphyrin could be used as a marker to screen and diagnose gastric and hepatic carcinoma.

The absence of an adverse effect of prolongation of radiation treatment of primary rectal adenocarcinoma

Many reports have shown a deleterious effect from the prolongation of radiation treatment duration on local control of squamous cell carcinomas in a variety of sites. To study whether a similar effect was found in adenocarcinoma of the rectum, a retrospective review was performed of 353 patients treated by external beam radiation therapy for primary adenocarcinoma of the rectum. At 4 years, the local control rate for mobile tumours was 25 percent; for fixed tumours it was 7 percent. By multiple Cox regression analysis, the only factor statistically significant for local control was tumour fixation (P=0.02). Neither treatment length (P=0.44), nor the presence of an interruption in treatment (P=0.41) was significant. The possible explanations for these observations are discussed.

Envelopment of varicella-zoster virus: targeting of viral glycoproteins to the trans-Golgi network

Previous studies suggested that varicella-zoster virus derives its final envelope from the trans-Golgi network (TGN) and that envelope glycoproteins (gps) are transported to the TGN independently of nucleocapsids. We tested the hypothesis that gpI is targeted to the TGN as a result of a signal sequence or patch encoded in its cytosolic domain. cDNAs encoding gpI wild type (wt) and a truncated mutant gpI(trc) lacking transmembrane and cytosolic domains were cloned by using the PCR. Cells transfected with cDNA encoding gpI(wt) or gpI(trc) synthesized and N glycosylated the proteins. gpI(wt) accumulated in the TGN, some reached the plasmalemma, but none was secreted. In contrast, gpI(trc) was retained and probably degraded in the endoplasmic reticulum; none was found on cell surfaces, but some was secreted. The distribution of gpI(trc) was not affected by deletion of potential glycosylation sites. To locate a potential gpI-targeting sequence, cells were transfected with cDNA encoding chimeric proteins in which the ectodomain of a plasmalemmal marker, the interleukin-2 receptor (tac), was fused to different domains of gpI. A chimeric protein in which tac was fused with the transmembrane and cytoplasmic domains of gpI was targeted to the TGN. In contrast, a chimeric protein in which tac was fused only with the gpI transmembrane domain passed through the TGN and concentrated in endosomes. We conclude that gpI is targeted to the TGN as a result of a targeting sequence or patch in its cytosolic domain.

Altered cAMP levels in retinas from transgenic mice expressing a rhodopsin mutant

Transgenic mice expressing the rhodopsin mutant Pro347Ser (Serine 6) display retinal degeneration through apoptosis that is characteristic of the disease retinitis pigmentosa. By 5 weeks after birth, these mice have lost approximately 35% of their photoreceptor cells. Retinas from these mice showed higher levels of cAMP compared to the levels in retinas of normal mice. Our studies provide evidence that elevated cAMP is common to the apoptotic process that occurs in retinitis pigmentosa. In addition, in vitro studies demonstrate no differences in the ability of the mutant and the wild-type rhodopsin to activate transducin, the rod cell G protein, to be phosphorylated by rhodopsin kinase or to bind arrestin. Mutants of rhodopsin, including Pro347Ser, are mistargeted to the rod inner segment, raising the possibility that rhodopsin triggers apoptosis through activation of signaling pathways not normally under its control.

[Lens epithelial proliferation induced by macrophages after intraocular lens implantation in rabbits]

To approach the effect of intraocular lens implantation on the mechanism of posterior capsular opacification, the pathological changes of posterior lens capsule after intraocular lens implantation in rabbits were observed by transmission electron microscopy. The results were as follows: In the control group, 1 week after the operation and the injection of the medium of the macrophage suspension, the lens posterior capsule was covered by a layer of lens epithelium and until post-operative 6 months, the lens epithelium remained normal. In the experimental group, 1 week after the operation and the injection of the macrophage suspension into the anterior chamber, microfilaments appeared in the cytoplasm of lens epithelial cells, after 2 weeks, the lens epithelial cells produced collagen fibrils in the extracellular matrix and until postoperative 3 months, 2-3 layers of the lens epithelium proliferated in front of the posterior capsule and a large amount of collagenous fibers were formed around the cells. It is suggested that the macrophage promote the lens epithelial proliferation and the posterior capsular opacification.