Oncostatin M signaling drives cancer-associated skeletal muscle wasting

Progressive weakness and muscle loss are associated with multiple chronic conditions, including muscular dystrophy and cancer. Cancer-associated cachexia, characterized by dramatic weight loss and fatigue, leads to reduced quality of life and poor survival. Inflammatory cytokines have been implicated in muscle atrophy; however, available anticytokine therapies failed to prevent muscle wasting in cancer patients. Here, we show that oncostatin M (OSM) is a potent inducer of muscle atrophy. OSM triggers cellular atrophy in primary myotubes using the JAK/STAT3 pathway. Identification of OSM targets by RNA sequencing reveals the induction of various muscle atrophy-related genes, including Atrogin1. OSM overexpression in mice causes muscle wasting, whereas muscle-specific deletion of the OSM receptor (OSMR) and the neutralization of circulating OSM preserves muscle mass and function in tumor-bearing mice. Our results indicate that activated OSM/OSMR signaling drives muscle atrophy, and the therapeutic targeting of this pathway may be useful in preventing muscle wasting.

Ectodysplasin A2 receptor signaling in skeletal muscle pathophysiology

Skeletal muscle is essential in generating mechanical force and regulating energy metabolism and body temperature. Pathologies associated with muscle tissue often lead to impaired physical activity and imbalanced metabolism. Recently, ectodysplasin A2 receptor (EDA2R) signaling has been shown to promote muscle loss and glucose intolerance. Upregulated EDA2R expression in muscle tissue was associated with aging, denervation, cancer cachexia, and muscular dystrophies. Here, we describe the roles of EDA2R signaling in muscle pathophysiology, including muscle atrophy, insulin resistance, and aging-related sarcopenia. We also discuss the EDA2R pathway, which involves EDA-A2 as the ligand and nuclear factor (NF)κB-inducing kinase (NIK) as a downstream mediator, and the therapeutic potential of targeting these proteins in the treatment of muscle wasting and metabolic dysfunction.

Parathyroid hormone related protein (PTHrP) in patients with pancreatic carcinoma and overt signs of disease progression and host tissue wasting

BACKGROUND

Cancer-cachexia is a complex syndrome secondary to physiological mechanisms related to classical hormone and immune alterations, where contributions of neuro-endocrine involvement have been less evaluated. Therefore, the aim of our study was to explore relationships between PTHrP and whole body metabolism in patients with progressive pancreatic carcinoma; relevant to "fat tissue browning".

METHODS

Patient serum samples and clinical information were retrieved from earlier translational projects (1995-2005), at Sahlgrenska University Hospital in Gothenburg. Blood PTHrP levels were determined at Harvard medical School (2014). Patient data included: medical history, clinical laboratory tests, food diaries, resting metabolic expenditure, body composition, exercise capacity, Health-Related Quality of Life (SF-36) and mental disorders (HAD-scales).

RESULTS

Serum PTHrP was detectable in 17 % of all samples without significance to tumor stage. PTHrP-negativity at inclusion remained during follow-up. Mean PTHrP concentration was 262±274 pg/ml, without sex difference and elevation over time. PTHrP-positive and negative patients experienced similar body weight loss (%) at inclusion, with a trend to deviate at follow ups (16.8±8.2% vs. 13.1±8.2%, p<0.06), where PTHrP concentrations showed correlations to weight loss, handgrip strength and Karnofsky performance, without difference in exercise capacity. PTHrP-positivity was related to increased whole body fat oxidation (p<0.006-0.01) and reduced carbohydrate oxidation (p<0.01-0.03), independently of peripheral lipolysis. Metabolic alterations in PTHrP-positive patients were related to reduced Health Related Quality of life (SF: p<0.08, MH: p<0.02), and increased anxiety and depression (HAD 1-7: p<0.004; HAD 8-14: p<0.008).

CONCLUSION

Serum PTHrP positivity in patients with pancreatic carcinoma was related to altered whole body oxidative metabolism; perhaps induced by "browning" of fat cells?

Muscle wasting: emerging pathways and potential drug targets

Muscle wasting is a serious comorbidity associated with many disorders, including cancer, kidney disease, heart failure, and aging. Progressive loss of skeletal muscle mass negatively influences prognosis and survival, and is often accompanied by frailty and poor quality of life. Clinical trials testing therapeutics against muscle wasting have yielded limited success. Some therapies improved muscle mass in patients without appreciable differences in physical performance. This review article discusses emerging pathways that regulate muscle atrophy, including oncostatin M (OSM) and ectodysplasin A2 (EDA2) receptor (EDA2R) signaling, outcomes of recent clinical trials, and potential drug targets for future therapies.

EDA2R-NIK signalling promotes muscle atrophy linked to cancer cachexia

Skeletal muscle atrophy is a hallmark of the cachexia syndrome that is associated with poor survival and reduced quality of life in patients with cancer¹. Muscle atrophy involves excessive protein catabolism and loss of muscle mass and strength². An effective therapy against muscle wasting is currently lacking because mechanisms driving the atrophy process remain incompletely understood. Our gene expression analysis in muscle tissues indicated upregulation of ectodysplasin A2 receptor (EDA2R) in tumour-bearing mice and patients with cachectic cancer. Here we show that activation of EDA2R signalling promotes skeletal muscle atrophy. Stimulation of primary myotubes with the EDA2R ligand EDA-A2 triggered pronounced cellular atrophy by induction of the expression of muscle atrophy-related genes Atrogin1 and MuRF1. EDA-A2-driven myotube atrophy involved activation of the non-canonical NFĸB pathway and was dependent on NFκB-inducing kinase (NIK) activity. Whereas EDA-A2 overexpression promoted muscle wasting in mice, deletion of either EDA2R or muscle NIK protected tumour-bearing mice from loss of muscle mass and function. Tumour-induced oncostatin M (OSM) upregulated muscle EDA2R expression, and muscle-specific oncostatin M receptor (OSMR)-knockout mice were resistant to tumour-induced muscle wasting. Our results demonstrate that EDA2R-NIK signalling mediates cancer-associated muscle atrophy in an OSM-OSMR-dependent manner. Thus, therapeutic targeting of these pathways may be beneficial in prevention of muscle loss.

Inhibition of epidermal growth factor receptor suppresses parathyroid hormone-related protein expression in tumours and ameliorates cancer-associated cachexia

BACKGROUND

Lung cancer is the primary cause of cancer deaths worldwide. Activation of epidermal growth factor receptor (EGFR) leads to lung cancer progression and poor prognosis while involuntary weight loss remains a major problem. Tumour-derived parathyroid hormone-related protein (PTHrP) emerged as a potential mediator of cachexia. Here, we investigated the modulatory role of EGFR signalling in PTHrP (encoded by Pthlh) gene expression and the impact of this relationship on cancer cachexia.

METHODS

Global gene expression profiles of Lewis lung carcinoma (LLC) cells were analysed. Pthlh mRNA levels were measured by qRT-PCR in LLC cells treated with EGFR ligands and tyrosine kinase inhibitors (TKIs). LLC tumour-bearing mice received EGFR TKI erlotinib for 7 days via intraperitoneal injection or oral gavage. Tumour Pthlh mRNA, weight of fat/muscle tissue, and grip strength were assessed. RNA-seq data from The Cancer Genome Atlas and gene expression analysis tools were used to characterize expression profiles of PTHLH and EGFR along with correlation analysis of PTHLH with EGFR and transforming growth factor alpha (TGFA) in human lung cancer and head and neck squamous carcinoma (HNSC). Survival of lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD) patients with EGFR gene alterations was analysed in regard to PTHLH expression.

RESULTS

Expression of EGFR ligands, EGFR itself, and PTHrP co-clusters in LLC cells. Activation of EGFR signalling with its ligands significantly increases (3.8-fold, P < 0.0005) while EGFR TKIs significantly decrease (90%, P < 0.0005) Pthlh mRNA levels in LLC cells. Pthlh mRNA drops 65-75% (P < 0.0005) in tumours upon treatment of LLC tumour-bearing mice with erlotinib while their muscle mass and grip strength increase (9.2% P < 0.05, 23% P < 0.005, respectively) compared with tumour-bearing control mice. PTHLH is overexpressed in tumours of LUSC (45.8-fold, P < 0.05) and HNSC (17.5-fold, P < 0.05) compared with normal tissue. PTHLH expression correlates with EGFR and its ligand TGFA in both cancers (LUSC: n = 745, R = 0.32, P < 0.0001 and R = 0.51, P < 0.0001; HNSC: n = 545, R = 0.34, P < 0.001 and R = 0.50, P < 0.001, respectively). High PTHLH mRNA associates with poor overall survival in LUAD patients with activating EGFR mutations (n = 40, log-rank test, P = 0.0451).

CONCLUSIONS

Epidermal growth factor receptor signalling regulates expression of cachexia mediator PTHrP. EGFR inhibition reduces PTHrP expression in LLC tumours and ameliorates cachexia in LLC tumour-bearing mice.

Metabolic Reprogramming in Adipose Tissue During Cancer Cachexia

Cancer cachexia is a disorder of energy balance characterized by the wasting of adipose tissue and skeletal muscle resulting in severe weight loss with profound influence on morbidity and mortality. Treatment options for cancer cachexia are still limited. This multifactorial syndrome is associated with changes in several metabolic pathways in adipose tissue which is affected early in the course of cachexia. Adipose depots are involved in energy storage and consumption as well as endocrine functions. In this mini review, we discuss the metabolic reprogramming in all three types of adipose tissues – white, brown, and beige – under the influence of the tumor macro-environment. Alterations in adipose tissue lipolysis, lipogenesis, inflammation and adaptive thermogenesis of beige/brown adipocytes are highlighted. Energy-wasting circuits in adipose tissue impacts whole-body metabolism and particularly skeletal muscle. Targeting of key molecular players involved in the metabolic reprogramming may aid in the development of new treatment strategies for cancer cachexia.

THE ASSOCIATION BETWEEN PRO AND ANTI-INFLAMMATORY MARKERS WITH THE COMPONENTS OF METABOLIC SYNDROME

Objectives

Metabolic syndrome (MetS) is a cluster of metabolic abnormalities that is linked with increased circulating markers of oxidative stress and low-grade inflammation. The link between inflammation and MetS is not yet fully understood. We aim to evaluate the relationship between the levels of pro and anti-inflammatory markers such as apolipoprotein A1 (Apo-A1), apolipoprotein B (Apo-B), interleukin (IL) 6, tumor necrosis factor alpha (TNF-α), fibrinogen and complement component 3 (C3) and adiponectin and MetS/MetS components.

Methods

This study was a case-control study conducted in an outpatient internal medicine clinic of the Ondokuz Mayıs University Internal Medicine Department. A total of 108 subjects (59 female, 49 male) who were not under any dietary restrictions and older than 17 years were selected and divided into two groups (54 with MetS and 54 healthy controls).

Results

Increased levels of IL-6, C3 and Apo-B/Apo-A1 ratios and decreased levels of Apo-A1 and TNF-α (except in patients with hypertriglyceridemia) were detected in the MetS group. Apo-A1 and TNF-α exhibited decreased levels, and IL-6, fibrinogen, C3 and Apo-B levels and Apo-B/Apo-A1 ratios increased as higher numbers of MetS criteria were met in the total study group.

Conclusions

We found that inflammatory marker levels were not affected by an increased number of MetS criteria met in the MetS group although these levels increased in the control group with higher numbers of MetS components. The presence of a high number of MetS components does not have an additive pro-inflammatory contribution for subjects already diagnosed with MetS.

Parathyroid Hormone Directs Bone Marrow Mesenchymal Cell Fate

Intermittent PTH administration builds bone mass and prevents fractures, but its mechanism of action is unclear. We genetically deleted the PTH/PTHrP receptor (PTH1R) in mesenchymal stem cells using Prx1Cre and found low bone formation, increased bone resorption, and high bone marrow adipose tissue (BMAT). Bone marrow adipocytes traced to Prx1 and expressed classic adipogenic markers and high receptor activator of nuclear factor kappa B ligand (Rankl) expression. RANKL levels were also elevated in bone marrow supernatant and serum, but undetectable in other adipose depots. By cell sorting, Pref1⁺RANKL⁺ marrow progenitors were twice as great in mutant versus control marrow. Intermittent PTH administration to control mice reduced BMAT significantly. A similar finding was noted in male osteoporotic patients. Thus, marrow adipocytes exhibit osteogenic and adipogenic characteristics, are uniquely responsive to PTH, and secrete RANKL. These studies reveal an important mechanism for PTH's therapeutic action through its ability to direct mesenchymal cell fate.

PTH/PTHrP Receptor Mediates Cachexia in Models of Kidney Failure and Cancer

Cachexia is a wasting syndrome associated with elevated basal energy expenditure and loss of adipose and muscle tissues. It accompanies many chronic diseases including renal failure and cancer and is an important risk factor for mortality. Our recent work demonstrated that tumor-derived PTHrP drives adipose tissue browning and cachexia. Here, we show that PTH is involved in stimulating a thermogenic gene program in 5/6 nephrectomized mice that suffer from cachexia. Fat-specific knockout of PTHR blocked adipose browning and wasting. Surprisingly, loss of PTHR in fat tissue also preserved muscle mass and improved muscle strength. Similarly, PTHR knockout mice were resistant to cachexia driven by tumors. Our results demonstrate that PTHrP and PTH mediate wasting through a common mechanism involving PTHR, and there exists an unexpected crosstalk mechanism between wasting of fat tissue and skeletal muscle. Targeting the PTH/PTHrP pathway may have therapeutic uses in humans with cachexia.

Tumour-derived PTH-related protein triggers adipose tissue browning and cancer cachexia

Cachexia is a wasting disorder of adipose and skeletal muscle tissues that leads to profound weight loss and frailty. About half of all cancer patients suffer from cachexia, which impairs quality of life, limits cancer therapy and decreases survival. One key characteristic of cachexia is higher resting energy expenditure levels than in healthy individuals, which has been linked to greater thermogenesis by brown fat. How tumours induce brown fat activity is unknown. Here, using a Lewis lung carcinoma model of cancer cachexia, we show that tumour-derived parathyroid-hormone-related protein (PTHrP) has an important role in wasting, through driving the expression of genes involved in thermogenesis in adipose tissues. Neutralization of PTHrP in tumour-bearing mice blocked adipose tissue browning and the loss of muscle mass and strength. Our results demonstrate that PTHrP mediates energy wasting in fat tissues and contributes to the broader aspects of cancer cachexia. Thus, neutralization of PTHrP might hold promise for ameliorating cancer cachexia and improving patient survival.

Nuclear receptors HNF4α and LRH-1 cooperate in regulating Cyp7a1 in vivo

Fibroblast growth factor 19 (FGF19) is a postprandial enterokine induced by the nuclear bile acid receptor, FXR, in ileum. FGF19 inhibits bile acid synthesis in liver through transcriptional repression of cholesterol 7α-hydroxylase (CYP7A1) via a mechanism involving the nuclear receptor SHP. Here, in a series of loss-of-function studies, we show that the nuclear receptors HNF4α and LRH-1 have dual roles in regulating Cyp7a1 in vivo. First, they cooperate in maintaining basal Cyp7a1 expression. Second, they enable SHP binding to the Cyp7a1 promoter and facilitate FGF19-mediated repression of bile acid synthesis. HNF4α and LRH-1 promote active transcription histone marks on the Cyp7a1 promoter that are reversed by FGF19 in a SHP-dependent manner. These findings demonstrate that both HNF4α and LRH-1 are important regulators of Cyp7a1 transcription in vivo.

Conversion of a paracrine fibroblast growth factor into an endocrine fibroblast growth factor

FGFs 19, 21, and 23 are hormones that regulate in a Klotho co-receptor-dependent fashion major metabolic processes such as glucose and lipid metabolism (FGF21) and phosphate and vitamin D homeostasis (FGF23). The role of heparan sulfate glycosaminoglycan in the formation of the cell surface signaling complex of endocrine FGFs has remained unclear. Here we show that heparan sulfate is not a component of the signal transduction unit of FGF19 and FGF23. In support of our model, we convert a paracrine FGF into an endocrine ligand by diminishing heparan sulfate-binding affinity of the paracrine FGF and substituting its C-terminal tail for that of an endocrine FGF containing the Klotho co-receptor-binding site to home the ligand into the target tissue. In addition to serving as a proof of concept, the ligand conversion provides a novel strategy for engineering endocrine FGF-like molecules for the treatment of metabolic disorders, including global epidemics such as type 2 diabetes and obesity.

Bullous skin reaction seen after extravasation of calcium gluconate

Intravenous (IV) calcium is usually given to temporarily treat the effects of hyperkalaemia on muscle and heart. When extravasation of a calcium gluconate infusion occurs, there may be rapid and marked swelling and erythema, with signs of soft-tissue necrosis or infection, and ensuing extensive local calcification, called calcinosis cutis. We report a 26-year-old woman who was hospitalized for exacerbation of acute intermittent porphyria. She had a history of hypertension and chronic renal failure. On the second day of her hospitalization, she developed hyperpotassaemia (6.7 mEq/L potassium; normal range 3.5-5 mEq/L). She was given an IV infusion of 10 mL calcium gluconate into the left dorsal pedal vein. Bullous skin reactions occurred in the infusion area nearly 2 h after administration. The patient's leg was elevated and the lesions cleaned with 0.9% saline. By day 9 of hospitalization, the lesions had markedly regressed. Several drugs have been associated with dermoepidermal blistering as an adverse drug reaction, but there is only one existing report in the literature about this side-effect associated with calcium gluconate. Clinicians should be alert to the possibility of bullous skin reactions, which may be a predictor of extravasation and necrosis, when treating patients with IV calcium gluconate.

Roles of FGF19 in liver metabolism

Fibroblast growth factor 19 (FGF19) is an ileum-derived postprandial enterokine that governs bile acid and nutrient metabolism. Synthesis of FGF19 is up-regulated by bile acids and, conversely, bile acid synthesis is down-regulated by FGF19. FGF19 also controls gallbladder volume. FGF19 has been shown to have profound effects on glucose and lipid metabolism. Recent studies have described FGF19 as a postprandial regulator of hepatic glucose and protein metabolism. Like insulin, FGF19 induces protein and glycogen synthesis and suppresses gluconeogenesis in liver. However, unlike insulin, FGF19 does not stimulate lipogenesis. A key difference between FGF19 and insulin lies in their use of different cellular signaling pathways. The beneficial effects of FGF19 on liver metabolism raise the question of whether FGF19 and its variants can be used as therapeutic agents in the treatment of diabetes.

FGF19 as a postprandial, insulin-independent activator of hepatic protein and glycogen synthesis

Fibroblast growth factor (FGF) 19 is an enterokine synthesized and released when bile acids are taken up into the ileum. We show that FGF19 stimulates hepatic protein and glycogen synthesis but does not induce lipogenesis. The effects of FGF19 are independent of the activity of either insulin or the protein kinase Akt and, instead, are mediated through a mitogen-activated protein kinase signaling pathway that activates components of the protein translation machinery and stimulates glycogen synthase activity. Mice lacking FGF15 (the mouse FGF19 ortholog) fail to properly maintain blood concentrations of glucose and normal postprandial amounts of liver glycogen. FGF19 treatment restored the loss of glycogen in diabetic animals lacking insulin. Thus, FGF19 activates a physiologically important, insulin-independent endocrine pathway that regulates hepatic protein and glycogen metabolism.

The G protein-coupled bile acid receptor, TGR5, stimulates gallbladder filling

TGR5 is a G protein-coupled bile acid receptor present in brown adipose tissue and intestine, where its agonism increases energy expenditure and lowers blood glucose. Thus, it is an attractive drug target for treating human metabolic disease. However, TGR5 is also highly expressed in gallbladder, where its functions are less well characterized. Here, we demonstrate that TGR5 stimulates the filling of the gallbladder with bile. Gallbladder volume was increased in wild-type but not Tgr5(-/-) mice by administration of either the naturally occurring TGR5 agonist, lithocholic acid, or the synthetic TGR5 agonist, INT-777. These effects were independent of fibroblast growth factor 15, an enteric hormone previously shown to stimulate gallbladder filling. Ex vivo analyses using gallbladder tissue showed that TGR5 activation increased cAMP concentrations and caused smooth muscle relaxation in a TGR5-dependent manner. These data reveal a novel, gallbladder-intrinsic mechanism for regulating gallbladder contractility. They further suggest that TGR5 agonists should be assessed for effects on human gallbladder as they are developed for treating metabolic disease.

A resampling-based meta-analysis for detection of differential gene expression in breast cancer

Background

Accuracy in the diagnosis of breast cancer and classification of cancer subtypes has improved over the years with the development of well-established immunohistopathological criteria. More recently, diagnostic gene-sets at the mRNA expression level have been tested as better predictors of disease state. However, breast cancer is heterogeneous in nature; thus extraction of differentially expressed gene-sets that stably distinguish normal tissue from various pathologies poses challenges. Meta-analysis of high-throughput expression data using a collection of statistical methodologies leads to the identification of robust tumor gene expression signatures.

Methods

A resampling-based meta-analysis strategy, which involves the use of resampling and application of distribution statistics in combination to assess the degree of significance in differential expression between sample classes, was developed. Two independent microarray datasets that contain normal breast, invasive ductal carcinoma (IDC), and invasive lobular carcinoma (ILC) samples were used for the meta-analysis. Expression of the genes, selected from the gene list for classification of normal breast samples and breast tumors encompassing both the ILC and IDC subtypes were tested on 10 independent primary IDC samples and matched non-tumor controls by real-time qRT-PCR. Other existing breast cancer microarray datasets were used in support of the resampling-based meta-analysis.

Results

The two independent microarray studies were found to be comparable, although differing in their experimental methodologies (Pearson correlation coefficient, R = 0.9389 and R = 0.8465 for ductal and lobular samples, respectively). The resampling-based meta-analysis has led to the identification of a highly stable set of genes for classification of normal breast samples and breast tumors encompassing both the ILC and IDC subtypes. The expression results of the selected genes obtained through real-time qRT-PCR supported the meta-analysis results.

Conclusion

The proposed meta-analysis approach has the ability to detect a set of differentially expressed genes with the least amount of within-group variability, thus providing highly stable gene lists for class prediction. Increased statistical power and stringent filtering criteria used in the present study also make identification of novel candidate genes possible and may provide further insight to improve our understanding of breast cancer development.

siRNA screening of the kinome identifies ULK1 as a multidomain modulator of autophagy

Autophagy is a vital response to nutrient starvation. Here, we screened a kinase-specific siRNA library using an autophagy assay in human embryonic kidney 293 cells that measures lipidation of the marker protein GFP-LC3 following amino acid starvation. This screen identified ULK1 in addition to other novel candidates that could be confirmed with multiple siRNAs. Knockdown of ULK1, but not the related kinase ULK2, inhibited the autophagic response. Also, ULK1 knockdown inhibited rapamycin-induced autophagy consistent with a role downstream of mTOR. Overexpression of ULK1 inhibited autophagy and this inhibition was independent of its kinase activity. Deletion of the PDZ domain-binding Val-Tyr-Ala motif at the ULK1 C terminus generated a more potent dominant-negative protein. Further deletions revealed that the minimal ULK1 dominant-negative region could be mapped to residues 1-351. Full-length ULK1 localized to cytoplasmic structures, some of which were GFP-LC3-positive, and this localization required the conserved C-terminal domain. In contrast, ULK1-(1-351) was diffuse in the cytoplasm. These experiments reveal at least two domains in ULK1 which likely function via unique sets of effectors to regulate autophagy.

Determination of lornoxicam in pharmaceutical preparations by zero and first order derivative UV spectrophotometric methods

Zero and first order derivative UV spectrophotometric methods were developed for the analysis of lornoxicam (LOR). The solutions of the standards and pharmaceutical samples were prepared in 0.05 N NaOH. Absorbances of LOR were measured at 376 nm for the zero order by measuring height of peak from zero and at 281 and 302 nm for the first order derivative spectrophotometric method by measuring peak to peak height. The linearity ranges were found to be 0.5-35 microg/mL for the zero order and 0.2-75 microg/mL for the first order derivative UV spectrophotometric method. The methods were validated and applied to the determination of LOR in pharmaceutical preparations (tablet and injectable, both containing 8 mg LOR). It was concluded that the methods developed were accurate, sensitive, precise, robust, rugged and useful for the quality control of LOR in pharmaceutical preparations.

Analysis of diflunisal by electrochemical methods

A new differential pulse polarographic (DPP) and differential pulse adsorptive stripping voltammetric (DPAdSV) methods for the electrochemical behavior and quantitative determination of diflunisal were described. In these voltammetric methods, the peak potential of diflunisal was found as -0.31 V (vs. Ag/AgCI) with selected Britton--Robinson buffer (BR, pH 7.8) as a supporting electrolyte. The variation of the peak current with the concentration of diflunisal were linear in the 9.0--40.0 and 4.0--30.0 microg ml(-1) concentration ranges for DPP and DPAdSV methods, respectively. The limits of detection (LOD) were found as 5.0 and 0.1 microg ml(-1) for DPP and DPAdSV methods, respectively. The developed methods were validated by evaluation of the validation parameters. The characteristics of the peak current of diflunisal were examined in detail and the results proved that the peak current has an adsorption characteristic. The developed methods were proposed for rapid determination of diflunisal in commercial tablets. The recovery studies showed that developed assays had a good accuracy and precision with mean recoveries 99.92 and 100.02% and mean variation coefficients 0.29 and 0.24% in DPP and DPAdSV methods, respectively.

Clinical effects of diflunisal and paracetamol in impacted mandibular third molar surgery

A double-blind, randomized, cross-over study to compare diflunisal and paracetamol for postoperative pain, swelling and trismus relief following impacted mandibular third molar surgery was designed. 25 patients received one of the drugs at one visit and the alternative at the other visit. First doses were given two hours preoperatively and continued twice daily for five days. The study was carried out to determine the effect of preoperatively used diflunisal on postoperative pain after surgical removal of the third molars as compared to paracetamol used in a similar manner. The degree of impaction, pain, swelling and mouth opening were assessed by standardized methods and possible adverse effects were also recorded separately. Statistical analysis was carried out by "Student's t test". (p < 0.01 statistically significant).

Serum calcium levels in various lung diseases

Calcium levels were determined in sera of patients suffering from various lung diseases. Healthy volunteers served as controls. Significant differences were found between the serum calcium levels of patients with active lung tuberculosis and those of controls (P less than 0.01). After treatment, serum calcium levels decrease to normal values in these patients. It was also found that there were significant differences in serum calcium levels of patients with primary lung carcinoma (P less than 0.01) and of patients with metastatic lung carcinoma as compared to controls (P less than 0.01). On the other hand, normal serum calcium levels were found in patients with pulmonary diseases with or without an infection. In conclusion, it seems likely that a combination of mechanisms plays a role in the pathogenesis of hypercalcaemia in pulmonary tuberculosis and primary and metastatic lung carcinoma.

The quantitative investigation of infrared laser effects on the levels of copper and zinc in various tissues

In order to study the effects of infrared laser irradiation on biological systems, the levels of copper and zinc in various irradiated tissues have been investigated. The zinc level in the muscle of the irradiated group increased (P less than 0.001) compared with the control group while in submandibular glands its level decreased (P less than 0.001). The copper levels in these two types of tissues decreased significantly (P less than 0.001). In irradiated skin, both copper and zinc levels increased compared with the control group (P less than 0.005). Quantitative determination of the trace elements copper and zinc indicated the necessity for more detailed studies of the effect of infrared laser irradiation at the cellular level.