High performance liquid chromatography determination of dexamethasone in plasma to evaluate its systemic absorption following intra-space pterygomandibular injection of twin-mix (mixture of 2 % lignocaine with 1:200,000 epinephrine and 4 mg dexamethasone): randomized control trial

Purpose

To determine systemic absorption of dexamethasone by detection of plasma concentration using high performance liquid chromatography following its administration along with local anesthetic agent as a mixture via pterygomandibular space.

Methods

A prospective randomized double-blind clinical study was undertaken to analyze the plasma concentration of dexamethasone after intra-space pterygomandibular injection along with local anesthesia. The study was performed as per split mouth model where the mandibular quadrant allocation was done on a random basis considering each of the 30 patients is included in the two study interventions (SS and CS). For the study site (SS) procedures, dexamethasone was administered as a mixture (2 % lignocaine with 1:200,000 epinephrine and 4 mg dexamethasone) intra-space. In the control site (CS) procedures, a regular standard inferior alveolar nerve block was administered, and dexamethasone was given as intramuscular injection. The plasma dexamethasone determination was done in venous blood 30- and 60-min post injection using high performance liquid chromatography (HPLC). The clinical parameters like pain; swelling; and mouth opening on the first, third, and seventh post-operative day were analyzed and compared.

Results

No significant difference was found in the clinical parameters assessed; comparative evaluation showed less swelling in the SS interventions. The plasma concentration of dexamethasone for the CS interventions was 226?±?47 ng/ml at 30-min and 316?±?81.6 ng/ml at 60-min post injection, and for SS, it was 221?±?81.6 ng/ml at 30-min and 340?±?105 ng/ml at 60-min post injection. On inter-site (CS and SS) comparison, no statistically significant difference was ascertained in dexamethasone plasma concentration at 30-min post injection (P?=?0.77) and at 60-min post injection. (P?=?0.32).

Conclusion

Intra-space (pterygomandibular space) administration of dexamethasone can achieve statistically similar plasma concentration of the drug as when the same dose is administered intramuscularly with demonstration of similar clinical effects.

     

Three patients with structurally abnormal X chromosomes, each with Xq13 breakpoints and a history of idiopathic acquired sideroblastic anemia

Structural abnormalities of the X chromosome are rarely found in neoplastic disorders. We describe three patients with a history of idiopathic acquired sideroblastic anemia (IASA); each one had an abnormal clone of cells in the bone marrow, characterized by a structurally abnormal X chromosome. In two of these patients, the predominant karyotype was 47,X,2idic(X)(q13); in the other patient, it was 46,X,t(X;11)(q13;p15). Inasmuch as all three of these cases involved chromosome band Xq13, as did two previously published cases, we suggest that band Xq13 may be more prone to structural rearrangement than other X chromosome bands in hematologic disorders. The common Xq13 chromosome breakpoint and clinical presentation (IASA) among these three patients and the occurrence of an X-linked type of sideroblastic anemia may suggest that an association exists between X chromosome abnormalities and IASA. Perhaps alteration of a gene or chromosome structure in or near band Xq13 predisposes to development of IASA. The fact that two of these patients had preleukemia and the third had overt acute leukemia may imply that patients with IASA and X chromosome abnormalities have a poor prognosis. Cases of IASA without associated X chromosome abnormalities are known; thus, if an association between IASA and an abnormal X chromosome does exist, most likely it involves only some patients with IASA.     

Evidence for Cytogenetic and Fluorescence In Situ Hybridization Risk Stratification of Newly Diagnosed Multiple Myeloma in the Era of Novel Therapies

Overall survival (OS) has improved with increasing use of novel agents in multiple myeloma (MM). However, the disease course remains highly variable, and the heterogeneity largely reflects different genetic abnormalities. We studied the impact of the Mayo risk-stratification model of MM on patient outcome in the era of novel therapies, evaluating each individual component of the model—fluorescence in situ hybridization (FISH), conventional cytogenetics (CG), and the plasma cell labeling index—that segregates patients into high- and standard-risk categories. This report consists of 290 patients with newly diagnosed MM, predominantly treated with novel agents, who were risk-stratified at diagnosis and were followed up for OS. Of these patients, 81% had received primarily thalidomide (n=50), lenalidomide (n=199), or bortezomib (n=79) as frontline or salvage therapies. Our retrospective analysis validates the currently proposed Mayo risk-stratification model (median OS, 37 months vs not reached for high- and standard-risk patients, respectively; P=.003). Although the FISH or CG test identifies a high-risk cohort with hazard ratios of 2.1 (P=.006) and 2.5 (P=.006), respectively, the plasma cell labeling index cutoff of 3% fails to independently prognosticate patient risk (hazard ratio, 1.4; P=.41). In those stratified as standard-risk by one of the 2 tests (FISH or CG), the other test appears to be of additional prognostic significance. This study validates the high-risk features defined by FISH and CG in the Mayo risk-stratification model for patients with MM predominantly treated with novel therapies based on immunomodulatory agents.CG = cytogenetics; CI = confidence interval; FISH = fluorescence in situ hybridization; HR = hazard ratio; IgH = immunoglobulin heavy chain; MM = multiple myeloma; mSMART = Mayo Stratification of Myeloma and Risk-Adapted Therapy; NR = not reached; PCLI = plasma cell labeling index; SCT = stem cell transplantationMultiple myeloma (MM) is a clonal plasma cell disorder that has witnessed considerable therapeutic advances in recent times. This progress can be attributed to improved antimyeloma therapy along with a better understanding of the tumor biology and heterogeneity.^1,2 Although a wide variation in overall survival (OS) of patients has been observed in studies analyzing the natural history of MM,³ only now are we beginning to associate the disparity in clinical outcomes with specific genetic abnormalities. Such chromosomal abnormalities are almost universally prevalent in the neoplastic plasma cells, typically occurring early in the disease process and dictating its course.⁴ Both cytogenetics (CG) and interphase fluorescence in situ hybridization (FISH) assays have played pivotal roles in the risk stratification of patients with newly diagnosed MM. Although still useful, conventional prognostic factors (β₂-microglobulin, lactate dehydrogenase, serum albumin, C-reactive protein, etc)⁵ appear to be somewhat less discerning of the outcome compared with the genetic aberrations that drive the tumor biology.^6-10The Mayo Stratification of Myeloma and Risk-Adapted Therapy (mSMART) criteria use a combination of metaphase CG, FISH, and plasma cell labeling index (PCLI; a measure of the percentage of plasma cells in the S phase of the cell cycle)¹¹ results to derive 2 composite risk categories (high-risk vs standard-risk) for prognostication of patients with newly diagnosed MM.¹² Although the initial prognostication criteria were based on the evidence predominantly garnered from patients treated with conventional chemotherapy and/or stem cell transplantation (SCT), the recommendations are periodically revised as new data emerge. Less than a decade ago, melphalan-prednisone or combination chemotherapies along with SCT were the mainstays of treatment of MM. The introduction of newer therapies, immunomodulatory drugs (thalidomide and lenalidomide), and the first-in-class proteasome inhibitor bortezomib ushered in a period of remarkable progress as the profound impact of such novel agents became evident early in the disease course.^1,13 Therefore, the Mayo prognostic model needed a formal assessment in the current era of expanded use of novel therapies. The objectives of our study were to evaluate the significance of the Mayo risk-stratification criteria since the integration of novel agents in the management of MM and to assess the independent prognostic value of each of the components (CG, FISH, and PCLI) in the model.     

An effective Australian-Chinese peer education program on HIV/AIDS/STDs for university students in China

<正> IntroductionCurrently,there are at least 850,000 peo-ple living with human immuno-deficiency virus(HIV) and acquired immuno-deficiency syn-drome (AIDS) in China.Among them 16-29years old account for about 65%.Accordingto the Chinese health authorities,if the pre-ventive measures are not effective,the figurecould reach as many as 10 million by the year2010.Since there are currently no cure or     

Informativeness of linkage analysis for genetic diagnosis of haemophilia A in India

The objective of this study was to assess the frequency of factor VIII (FVIII) gene intron 1 and intron 22 inversions and the informativeness of polymorphic markers for the genetic diagnosis of patients with haemophilia A (HA). Fifty unrelated patients with HA were first assessed for the intron 1 and intron 22 inversion mutations. Inversion-negative families were then screened for the bi-allelic intragenic markers--intron 7 G-->A polymorphism, HindIII site in intron 19 and XbaI site in intron 22 and the multiallelic dinucleotide CA repeat alleles in introns 13 and 22. The extragenic, multiallelic VNTR DXS52 (st14) was also analysed. Intron 22 inversion mutation was found in 38% (n = 19) of all patients and 46% of those with severe HA. Intron 1 inversion was found in one (2%) patient. Of the 30 inversion-negative families, XbaI site polymorphism was the single most informative marker (70%, n = 21/30) followed by HindIII (60%, n = 18/30), intron 13 CA repeats (56.66%, n = 17/30), intron 22 CA repeats (50%, n = 15/30), DXS52 VNTR (23.33%, n = 7/30) and intron 7 G-->A polymorphism (6.66%, n = 2/30). The combined use of these markers was informative in 92% (n = 46/50) of HA families. Based on the informativeness of these markers a comprehensive algorithm has been proposed for genetic diagnosis of HA in India.