Plasma EBV DNA and cell-free GAPDH DNA as prognostic factors of locally advanced nasopharyngeal carcinoma

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Background: Plasma cell-free nucleic acids have been investigated to be potential prognostic and predictive markers of treatment response, residual disease, and survival of cancer patients. However, these nucleic acids will be confounded by normal cell death, which might be caused by cancer-related inflammation, infection, or chemotherapy. Nasopharyngeal carcinoma is endemic in Taiwan, highly related to EBV infection. Plasma EBV DNA level has been suggested to be predictive of disease status and outcomes. We try to find out whether plasma EBV and cell-free glyceraldehydes-3-phosphate dehydrogenase DNA before definite treatment of locally advanced NPC predict tumor outcomes better. Methods: 144 stage IV (AJCC version 6) NPC patients received induction chemotherapy followed by concurrent chemoradiotherapy in National Taiwan University Hospital from 1998 to 1999. Pre-treatment blood samples were colleted for real-time quantitative polymerase chain reactions of EBV and GAPDH DNA. The results will be analyzed by SPSS version 13 to see if correlated with tumor extent, locoregional/distant failure, and overall survival. Results: Our patients were mainly composed of T4(97%) and N2(56%) patients. 23 % were in N3 stage. Plasma EBV and cell-free GAPDH DNA levels were not correlated with T stage. Plasma EBV DNA level was significantly correlated with N3 status(Mann-Whitney test p=0.021). After Cox regression model, only age (p=0.024) was a significant predictor of recurrence-free survival; N3 status(p=0.007) and positive plasma EBV DNA (p=0.002) predicted shorter metastasis-free survival. N3 status (p=0.031) and positive plasma EBV DNA (p=0.002) were significantly related to poor survival by log-rank test; whereas T4 lesions (p=0.524) and plasma cell-free GAPDH DNA level (p=0.182) were not. After multivariate Cox regression, positive plasma EBV DNA (hazard ratio 4.936 p=0.006) was the only significant predictor of poor survival. Conclusions: To use circulating DNA as prognostic marker, a specific one, such as EBV DNA, might be better than a non-specific one, like GAPDH DNA. This is important in the development of tumor markers for other solid tumors.

No significant financial relationships to disclose.

Epidemiology of obesity and hypertension and related risk factors in Uzbekistan

OBJECTIVE

This study examined the prevalence of obesity and hypertension and associated behavioral risk factors in adult men and women in Uzbekistan. The study also examined the association between obesity and hypertension.

METHOD

The analysis used data from the 2002 Uzbekistan Health Examination Survey, which included a nationally representative sample of 2333 men aged 15-59 years and 5463 women aged 15-49 years. The survey measured height, weight and blood pressure and included questions on physical activity, dietary habits, tobacco smoking, alcohol use and other characteristics. The analysis was conducted using binary and multinomial logistic regression methods, separately for men and women.

RESULTS

Eating animal source protein and tobacco smoking in the past were positively associated with obesity, but there were no consistent associations with other dietary indicators, physical activity level or alcohol use. Obese men and women were about three times as likely to suffer from hypertension as those with a normal BMI (odds ratio (OR)=3.01; 95% confidence interval (CI): 1.67-5.44; P<0.001 for men and OR=2.82; 95% CI: 2.05-3.86; P<0.001 for women), independent of physical activity level, dietary habits, tobacco smoking and other factors. For men, the risk of hypertension was strongly positively associated with BMI only at BMI levels above 25 kg/m(2), but for women a positive relationship was observed at all BMI levels.

CONCLUSION

The study found a strong positive association between obesity and hypertension in adult men and women in Uzbekistan. The shape of the relationship between BMI and hypertension is different for women than for men, requiring further research to explore this relationship.

Effects of extra immunization efforts on routine immunization at district level in Pakistan

A study was made of the effects of extra immunization activities on routine immunization coverage at district level in Pakistan in a secondary analysis of data from UNICEF and the Pakistan national census. Linear regression analysis was made on data from 107 districts to estimate the effects of extra immunization efforts in the national neonatal tetanus programme on the coverage rate of the third dose of diphtheria-pertussis-tetanus (DPT3) after controlling for other potential confounding factors. The districts that implemented extra national neonatal tetanus immunization were at risk of having lower routine DPT3 coverage than those that did not. Additional immunization efforts, without additional resources, may reduce the effect of the routine Expanded Programme on Immunization.

Characterization of the functional interaction of adipocyte lipid-binding protein with hormone-sensitive lipase

Hormone-sensitive lipase (HSL) is an intracellular lipase that plays an important role in the hydrolysis of triacylglycerol in adipose tissue. HSL has been shown to interact with adipocyte lipid-binding protein (ALBP), a member of the family of intracellular lipid-binding proteins that bind fatty acids and other hydrophobic ligands. The current studies have addressed the functional significance of the association and mapped the site of interaction between HSL and ALBP. Incubation of homogeneous ALBP with purified, recombinant HSL in vitro resulted in a 2-fold increase in substrate hydrolysis. Moreover, the ability of oleate to inhibit HSL hydrolytic activity was attenuated by co-incubation with ALBP. Co-transfection of Chinese hamster ovary cells with HSL and ALBP resulted in greater hydrolytic activity than transfection of cells with HSL and vector alone. Deletional mutations of HSL localized the region of HSL that interacts with ALBP to amino acids 192-200, and site-directed mutagenesis of individual amino acids in this region identified His-194 and Glu-199 as critical for mediating the interaction of HSL with ALBP. Interestingly, HSL mutants H194L and E199A, each of which retained normal basal hydrolytic activity, failed to display an increase in hydrolytic activity when co-transfected with wild type ALBP. Therefore, ALBP increases the hydrolytic activity of HSL through its ability to bind and sequester fatty acids and via specific protein-protein interaction. Thus, HSL and ALBP constitute a functionally important lipolytic complex.

A compendium of gene expression in normal human tissues

This study creates a compendium of gene expression in normal human tissues suitable as a reference for defining basic organ systems biology. Using oligonucleotide microarrays, we analyze 59 samples representing 19 distinct tissue types. Of approximately 7,000 genes analyzed, 451 genes are expressed in all tissue types and designated as housekeeping genes. These genes display significant variation in expression levels among tissues and are sufficient for discerning tissue-specific expression signatures, indicative of fundamental differences in biochemical processes. In addition, subsets of tissue-selective genes are identified that define key biological processes characterizing each organ. This compendium highlights similarities and differences among organ systems and different individuals and also provides a publicly available resource (Human Gene Expression Index, the HuGE Index, http://www.hugeindex.org) for future studies of pathophysiology.

The thymus. Finally getting some respect

The thymus gland is no longer a structure in the anterior mediastinum of questionable use in the body economy. It is the sole source of cells that control the immune response and provide protection from life-threatening pathogens. Its primary function is to seed the periphery with mature T cells. Because these cells can maintain their numbers through self-replication, thymic function essentially is completed within the first few years of life. In response to a lack of need for its services, the thymus thereupon undergoes involution. A demand for renewed thymopoiesis has become necessary as the T-cell compartment of the immune system must be replenished following massive depletion of T cells by disease (e.g., AIDS) or the demands of cytoreduction necessary to achieve successful bone marrow transplantation. In older patients with AIDS (> 20-30 years), re-expansion of the post-thymic population may be adequate to restore the patient to reasonable or even normal T-cell immunity, but when the cytoablation is as massive as seen with bone marrow transplant conditioning regimens, the thymus must contribute to the repopulation. If involution has proceeded too far, thymic output must be augmented. This augmentation can be accomplished by thymus transplantation. The techniques for successful thymus transplantation in adults, however, have yet to be perfected. The thymus can play a major role in determining the response to MHC products of others (i.e., nonself). Novel manipulations of the thymus are being used to achieve transplant tolerance.

N-terminal intramolecularly conserved histidines of three domains in Gonyaulax luciferase are responsible for loss of activity in the alkaline region

Gonyaulax luciferase is a single-chain ( approximately 137 kDa) polypeptide comprising 111 N-terminal amino acids followed by three contiguous homologous domains (377 amino acids each). Each domain has luciferase activity, accounting for the earlier observation that proteolytic fragments ( approximately 35 kDa) of luciferase are active. The activity of the full-length native enzyme is maximal at pH 6.3, dropping to near zero at pH 8; the activity of fragments also peaks at pH 6.3 but remains high at 8. While the activity loss at higher pH might be thought to be associated with the conformation of the full-length protein, we show here that this is a property of individual domains. The three intramolecularly homologous domains, separately cloned and expressed in Escherichia coli as fusion proteins, exhibit pH-activity curves similar to that of the full-length enzyme. For each domain the removal of approximately 50 N-terminal amino acids resulted in an increase in the ratio of luciferase activity at pH 8 relative to that at pH 6.3, such that their pH-activity profiles mimicked that of the proteolytic fragments reported earlier. Replacement of N-terminal histidines by alanine by site-directed mutagenesis identified four that are involved in the loss of activity at high pH. This system illustrates an unusual, possibly unique mechanism for pH regulation of enzyme activity, which has been postulated to be responsible for the control of the characteristic flashes of bioluminescence.

The DiGeorge anomaly

The DiGeorge anomaly, originally considered a clinical paradigm for isolated thymus deficiency, has now been redefined as a member of a group of disorders that share in common a chromosome deletion resulting in monosomy 22q11 (CATCH-22 or DGA/VCFS). In addition to the thymus defect, conotruncal heart anomalies, dysmorphism, hypoparathyroidism, and cleft palate are prominent features. Despite the emphasis on thymus involvement in DGA, a clinically significant thymus defect is found only in a small percentage of these patients probably occurring in less than 5% of the cases. Maldescent of the thymus, however, is extremely common, leading to an absence of mediastinal thymic tissue in nearly all cases. The basic embryological fault in these disorders is an inadequate development of the facial neural-crest tissues, resulting in defective organogenesis of pharyngeal pouch derivatives that receive cephalic neural-crest contribution to the mesenchmyme. The causes for this maldevelopment are both genetic and extragenetic in origin and the genetic lesions act in concert with random environmental events to produce the ultimate clinical picture. The modern research approaches now available have cleared away most of the confusion clouding the clinical and theoretical aspects of DGA and related disorders, providing the clinician with useful landmarks to assess and treat these intriguing clinical challenges.

Correction of DiGeorge anomaly with EBV-induced lymphoma by transplantation of organ-cultured thymus and Epstein-Barr-specific cytotoxic T lymphocytes

A young woman with DiGeorge anomaly showed normal immune tests as a child and did not experience the symptoms of profound T cell immunodeficiency. However, she had chronic pulmonary infections which led to bronchiectasis. At age 14, she developed an Epstein-Barr virus-induced lymphoma and her T cell function tests were markedly abnormal. After intensive chemotherapy, she received an organ-cultured thymus transplant but because of an abnormally high EBV DNA titer was also given autologous EBV-specific cytotoxic T cells, prepared prior to transplant. Titers fell from 80,000 genome copies/mg DNA to 2000 within 6 weeks. She was clinically well and her T cell tests improved. Sixteen months after the transplant, however, her tumor returned; EBV DNA levels had risen to 40,000 copies/mg DNA. She again received autologous EBV-specific cytotoxic T lymphocytes and valcyclovir and Cytogam as well. Her tumor resolved on this therapy and she has remained well to this date, 29 months after the recurrence. T cell tests, which had deteriorated with the recurrence of the tumor, now show normal responses. This experience records a number of unique features of thymus transplantation. This is the first recorded successful thymus transplant in a patient with partial T cell immunity and thus expands the potential of this treatment modality to patients other than infants with complete DiGeorge anomaly. The patient demonstrates cytotoxic activity against mouse cells, demonstrating the ability to respond to a new antigen which requires host antigen presenting cells. Measurement of alpha 1 TRECs (T cell receptor excision circles) shows evidence of increasing and sustained thymopoiesis since the transplant at a level consistent with the age of the transplant donor rather than that of the recipient.

[The measurement of normal values of exophthalmos, interpupillary distance and interorbital distance of children and adolescence in Xiamen and the rule of their development]

OBJECTIVE

To investigate the developing rhythm of children and adolescent exophthalmos, interorbital distance (IOD) and interpupillary distance (IPD) and their mutual relationships. The study will provide biometry data for formulating juvenile criteria of correcting spectacles.

METHODS

Random sampling was performed among children and adolescence aged 5 - 17 years in Xiamen. Adopting epidemic survey, we measured the biometry values of IOD, IPD and exophthalmos with a sliding gauge and exophthalmometer.

RESULTS

The average value of exophthalmos was (14.48 +/- 1.71) mm. For the 5 - 8 years old children, the value of exophthalmos trended to increase with the increase of age, meanwhile the value of exophthalmos of adolescence aged 9 - 17 years old tended to be stabilized. The average value of IOD was (95.55 +/- 5.32) mm and the average value of IPD was (56.99 +/- 3.93) mm. Both the values of the IOD and IPD of the male were higher than that of the female. The results of the IOD and IDP distance increased with the increase of age and it trended to be periodic. There was positive correlation between the development of IOD and that of IPD, and it could be described by a linear equation.

CONCLUSIONS

There is only one rush-increase stage of ocular development which is before the 8 years old in children. The rule of its development is in accordance with the growing and developing mode of neurological system.

Hormone-sensitive lipase functions as an oligomer

Hormone-sensitive lipase (HSL) is a cytosolic neutral lipase whose activity is regulated by reversible phosphorylation and which is thought to be the rate-limiting enzyme for the mobilization of FFA from adipose tissue. In the current studies the subunit structure of HSL has been explored using sucrose gradient centrifugation and in vivo and in vitro protein-protein interactions. Evidence is provided to demonstrate that HSL exists as a functional dimer composed of homologous subunits. Dimeric HSL displayed approximately 40-fold greater activity against cholesteryl ester substrate when compared with monomeric HSL without any differences in affinity for the substrate. Truncations of HSL identified the importance of the N-terminal 300 amino acids, as well as other regions, in participating in the oligomerization of HSL. These studies support the notion that the N-terminal region of HSL represents a docking domain for protein-protein interactions and provide an additional mechanism for the posttranslational control of HSL activity in the cell via oligomerization.

Evaluation of toxic assault on the immune system

As a consequence of increased industrialization, human exposure to environmental toxins is growing daily. The effects of this exposure on the immune system is potentially a major health problem. Studies following human exposure have not unambiguously demonstrated a biologically significant weakening of the immune system, primarily because tests which show a high correlation with disease susceptibility have not been utilized. Such assessment of the immune system is particularly important in developing countries where regulation of environmental contamination may be less vigorous. At the same time, the ability to perform screening of large population in this setting is impaired. Measurement of the antibody response to an antigen used for routine immunizations provides a simple but very informative assessment and is particularly well suited as a minimalist approach to immune system assessment in developing countries.

The DiGeorge anomaly (CATCH 22, DiGeorge/velocardiofacial syndrome)

The DiGeorge anomaly (DGA), originally considered a clinical paradigm for isolated thymus deficiency, has now been redefined as a member of a group of disorders that share in common a chromosome deletion, which results in monosomy 22q11 (CATCH-22 or DiGeorge/velocardiofacial [VCFS] syndrome). In addition to the thymus defect, conotruncal heart anomalies, dysmorphism, hypoparathyroidism, and cleft palate are prominent features. Despite the emphasis on thymus involvement in DGA, a clinically significant thymus defect is found only in a small percentage of these patients. The basic embryological fault in these disorders is an inadequate development of the facial neural crest tissues, resulting in defective organogenesis of pharyngeal pouch derivatives. Although first described by an endocrinologist, this experiment of nature has become a major subject of investigation for geneticists and immunologists. Elucidation of the etiology and attempts to effectively treat the diverse clinical problems continue to challenge and stimulate many disciplines of medicine both in the laboratory and at the bedside.

Small abundant DNA binding proteins from the thermoacidophilic archaeon Sulfolobus shibatae constrain negative DNA supercoils

Major DNA binding proteins, designated Ssh7, were purified from the thermoacidophilic archaeon Sulfolobus shibatae. The Ssh7 proteins have an apparent molecular mass of 6.5 kDa and are similar to the 7-kDa DNA binding proteins from Sulfolobus acidocaldarius and Sulfolobus solfataricus in N-terminal amino acid sequence. The proteins constitute about 4.8% of the cellular protein. Upon binding to DNA, the Ssh7 proteins constrain negative supercoils. At the tested Ssh7/DNA mass ratios (0 to 1.65), one negative supercoil was taken up by approximately 20 Ssh7 molecules. Our results, together with the observation that the viral DNA isolated from S. shibatae is relaxed, suggest that regions of free DNA in the S. shibatae genome, if present, are highly positively supercoiled.

[Primary posterior chamber intraocular lens implantation of posterior capsular ruptur with cataract extracted by phacoemulsification]

OBJECTIVE

To evaluate the effect of primary posterior chamber intraocular lens (IOL) implantation of posterior capsular rupture (PCR) with cataract extracted by phacoemulsification.

METHOD

Primary posterior chamber IOL implantation was performed on 29 cases (29 eyes) with PCR occurring in 184 cases (200 eyes) during cataract extraction by phacoemulsification.

RESULTS

In-the-bag implantation was performed on 10 cases, and sulcus-fixed lens implantation on 19 cases. The post-operative uncorrected visual acuities in 17 cases (58.62%) were 1.0 or better and 0.5 - 0.9 in 10 cases (34.48%). The corrected visual acuities in 22 cases (75.86%) were 1.0 or better and 0.5 - 0.9 in 5 cases (17.24%) after 3 months of operation. The complications included corneal edema and damage of pupillary margin in the operation, and anterior vitreous inflammatory reaction after the operation.

CONCLUSION

The posterior chamber IOL can be primarily implanted in cases with PCR and functional anterior or posterior capsular support after the anterior segment vitreous was cleaned.

An adenosine deaminase (ADA) allele contains two newly identified deleterious mutations (Y97C and L106V) that interact to abolish enzyme activity

Genetic deficiency of the purine salvage enzyme adenosine deaminase (ADA) results in varying degrees of immunodeficiency, ranging from neonatal onset Severe Combined Immunodeficiency (SCID) to an adult onset immunodeficiency disorder. Multiple different mutations have now been identified in these immunodeficient patients. Additional mutations, initially identified in healthy individuals, abolish ADA in erythrocytes but retain 10-80% of activity in non-erythroid cells ('partial deficiency mutations'). In general, severity of disease correlates inversely with the amount of residual ADA expressed by the mutant enzymes and directly with the accumulation of the toxic metabolites deoxyATP and deoxyadenosine. We report two newly identified mutations (Y97C and L106V), both carried on the same allele of an immunodeficient patient who was diagnosed prenatally and successfully transplanted with haploidentical bone marrow. Based on the ability of mutant cDNAs to express ADA in vitro , the L106V mutation resulted in activity similar to 'partial' mutations (30% of normal) while the Y97C mutation resulted in detectable but markedly reduced activity (1.5% of normal). However, the presence of both mutations on the same allele virtually abolished detectable enzyme activity. Analysis of the crystallographic structure of ADA to understand the marked deleterious effect of the Y97C mutation suggested a previously unappreciated role of salt bridges in the catalytic mechanism of ADA. The patient was also heteroallelic for a previously described deletion of the promoter and exon 1. Testing of additional patients in whom we had not identified a mutation on the second allele revealed presence of this deletion in three of four patients tested. This deletion is therefore relatively common, accounting for 10% of almost 100 chromosomes studied by this and other laboratories, but is easily missed by currently used methods of mutation detection. Lastly, the finding of two mutations on the same allele that interact to reduce residual enzyme function emphasizes hazards in evaluating potential genotype-phenotype correlations in individuals analyzed only for the presence of single specific mutations.