The role of norepinephrine in the regulation of fluid absorption in the rat proximal tubule

In order to investigate the possibility of a direct effect of adrenergic transmitter on tubular fluid absorption, we have studied the effects of norepinephrine and phenoxybenzamine on fluid absorption in the proximal convoluted tubule of the rat kidney. Net fluid absorption (Jv) was determined in the same proximal convoluted tubule before and after addition of norepinephrine or phenoxybenzamine while the tubular lumen and peritubular capillaries were simultaneously microperfused in situ. When the tubular lumen was perfused with Ringer's solution and the peritubular capillaries were perfused with albumin Ringer's solution, Jv was 2.85 +/- 0.25 nl/min X nm. Addition of 2 X 10(-6) M norepinephrine to the capillary perfusate caused at 30% increase in Jv which could be reversed by removing the adrenergic transmitter. The effect of norepinephrine was dose dependent with the maximal increase of Jv observed at a concentration of 10(-5) M. Addition of 2 X 10(-6) M phenoxybenzamine to the capillary perfusate caused a 16% decrease in Jv while the simultaneous administration of norepinephrine and phenoxybenzamine to the capillary perfusate caused a 25% decrease in Jv. On the other hand, there was no effect observed on Jv when either norepinephrine or phenoxybenzamine was added to the luminal perfusate. These results suggest that adrenergic nerves may participate in the regulation of tubular fluid absorption through the direct action of norepinephrine on alpha adrenergic receptors located on the basolateral membrane of proximal tubular cells.     

Molecular diagnosis of primary mediastinal B cell lymphoma identifies a clinically favorable subgroup of diffuse large B cell lymphoma related to Hodgkin lymphoma

Using current diagnostic criteria, primary mediastinal B cell lymphoma (PMBL) cannot be distinguished from other types of diffuse large B cell lymphoma (DLBCL) reliably. We used gene expression profiling to develop a more precise molecular diagnosis of PMBL. PMBL patients were considerably younger than other DLBCL patients, and their lymphomas frequently involved other thoracic structures but not extrathoracic sites typical of other DLBCLs. PMBL patients had a relatively favorable clinical outcome, with a 5-yr survival rate of 64% compared with 46% for other DLBCL patients. Gene expression profiling strongly supported a relationship between PMBL and Hodgkin lymphoma: over one third of the genes that were more highly expressed in PMBL than in other DLBCLs were also characteristically expressed in Hodgkin lymphoma cells. PDL2, which encodes a regulator of T cell activation, was the gene that best discriminated PMBL from other DLBCLs and was also highly expressed in Hodgkin lymphoma cells. The genomic loci for PDL2 and several neighboring genes were amplified in over half of the PMBLs and in Hodgkin lymphoma cell lines. The molecular diagnosis of PMBL should significantly aid in the development of therapies tailored to this clinically and pathogenetically distinctive subgroup of DLBCL.     

Predictive value of pretreatment metabolic activity measured by fluorodeoxyglucose positron emission tomography in patients with metastatic advanced gastric cancer: the maximal SUV of the stomach is a prognostic factor

Purpose

Few studies have evaluated metabolic activity by ¹⁸F-FDG PET as a prognostic factor in advanced gastric cancer (AGC). We investigated its prognostic role in metastatic AGC.

Methods

We enrolled 82 patients with metastatic AGC, who were treatment-naive and underwent pretreatment ¹⁸F-FDG PET/CT scanning. In each patient, the maximal standardized uptake value (SUVmax) was measured in each target lesion. Stomach_SUVmax was defined as SUVmax in the stomach, while Total_SUVmax was defined as the highest SUVmax among all the target lesions.

Results

The stomach was the organ most frequently displaying the highest SUVmax among all the target lesions (in 67.1?% of patients). A Total_SUVmax value of 11.5 was the value with the maximum sum of sensitivity and specificity from receiver-operating characteristic curves for progression-free survival (PFS). PFS was significantly longer in patients with a Total_SUVmax value <11.5 than in those with a Total_SUVmax value ≥11.5 (P?=?0.023); however, overall survival (OS) was not (P?=?0.055). A Stomach_SUVmax value of 6.0 was derived by similar methods. PFS and OS were significantly longer in those with a Stomach_SUVmax value <6.0 than in those with a Stomach_SUVmax value ≥6.0 (P?=?0.001 and P?=?0.006, respectively). Furthermore, those with a low Total_SUVmax and those with a low Stomach_SUVmax showed better chemotherapeutic responses (P?=?0.016 and P?=?0.034, respectively). Among patients with histologically undifferentiated carcinomas, those with lower Total_SUVmax and those with lower Stomach_SUVmax showed longer median PFS (P?=?0.027 and P?=?0.005, respectively) and OS (P?=?0.009 and P <0.001, respectively). Multivariate analysis demonstrated Stomach_SUVmax as an independent predictor of PFS (P?=?0.002) and OS (P?=?0.038).

Conclusion

Pretreatment metabolic activity may be a useful prognostic marker in patients with metastatic AGC undergoing palliative chemotherapy. Notably, Stomach_SUVmax was the single, most robust factor predicting prognosis.     

Effectiveness of a lifestyle modification programme in weight maintenance in obese subjects after cessation of treatment with Orlistat

OBJECTIVE: To examine the efficacy of a lifestyle modification programme in weight maintenance for obese subjects after cessation of treatment with Orlistat. METHODS: Fifty-five subjects with and without diabetes mellitus were randomized to a lifestyle modification programme or to usual care at the end of 6 months' treatment with Orlistat. The intervention programme was nutritionist led, consisting of components of dietary management, physical activity, peer group support and discussion using techniques of self-monitoring, stimulus control and cognitive restructuring. Anthropometric indices, body composition, basal metabolic rate, blood pressure, fasting glucose, glycosylated haemoglobin, lipid profile, 24-hour urinary albumin excretion, dietary intake, physical activity level, and quality of life were assessed before and after the intervention period. Results Subjects in the intervention group maintained their weight loss and favourable anthropometric, metabolic, dietary intake, physical activity and quality of life profiles, while most parameters deteriorated in the usual care group, being more marked in subjects with diabetes. The magnitude of weight gain was comparable to that lost during Orlistat treatment. CONCLUSION: A specially designed nutritionist-led lifestyle modification programme for obese subjects is effective in weight maintenance after treatment with Orlistat, in the absence of which the benefits of drug treatment were lost. The magnitude of the effect of lifestyle modification is comparable to that observed with Orlistat.     

Contact thermography of painful diabetic neuropathic foot.

OBJECTIVE: To investigate regional differences in skin blood flow (measured by contact thermography) in the diabetic neuropathic foot and to examine the effect of foot temperature on the severity of neuropathic pain. RESEARCH DESIGN AND METHODS: Thirty-five diabetic patients with painful polyneuropathy (PPN) and 33 healthy age- and sex-matched control subjects comprised the study. Mean foot temperature (MFT) in PPN (mean +/- SE 28.3 +/- 0.3 degrees C) was significantly higher (P less than 0.001) than in the control subjects (25.9 +/- 0.5 degrees C), with the highest temperatures over the metatarsal areas and heel. Visual analogue scale pain score (mean +/- SD 5.3 +/- 1.9 cm) did not correlate with MFT (r = -0.14, P = 0.52). In 10 patients with PPN followed for 2-8 mo (mean 4.6), MFT fell by 1.6 degrees C (P = 0.05), but pain scores did not alter. CONCLUSIONS: Neuropathic pain is unaffected by alterations in skin temperature. Elevated skin temperatures at recognized sites of weight bearing (metatarsal heads and heels) are common in the diabetic neuropathic foot and may indicate tissue injury or inflammation induced by pressure trauma or increased arteriovenous shunting. Follow-up studies will determine whether thermographic hot spots are more susceptible to ulceration.     

Residues Distal to the Active Site Contribute to Enhanced Catalytic Activity of Variant and Hybrid β-Lactamases Derived from CTX-M-14 and CTX-M-15

A variety of CTX-M-type extended-spectrum β-lactamases (ESBLs), including hybrid ones, have been reported in China that are uncommon elsewhere. To better characterize the substrate profiles and enzymatic mechanisms of these enzymes, we performed comparative kinetic analyses of both parental and hybrid CTX-M enzymes, including CTX-M-15, -132, -123, -64, -14 and -55, that are known to confer variable levels of β-lactam resistance in the host strains. All tested enzymes were susceptible to serine β-lactamase inhibitors, with sulbactam exhibiting the weakest inhibitory effects. CTX-M-55, which differs from CTX-M-15 by one substitution, A⁷⁷V, displayed enhanced catalytic activity (k_cat/K_m) against expanded-spectrum cephalosporins (ESCs). CTX-M-55 exhibits higher structure stability, most likely by forming hydrophobic interactions between A⁷⁷V and various key residues in different helices, thereby stabilizing the core architecture of the helix cluster, and indirectly contributes to a more stable active site conformation, which in turn shows higher catalytic efficiency and is more tolerant to temperature change. Analyses of the hybrids and their parental prototypes showed that evolution from CTX-M-15 to CTX-M-132, CTX-M-123, and CTX-M-64, characterized by gradual enhancement of catalytic activity to ESCs, was attributed to introduction of different substitutions to amino acids distal to the active site of CTX-M-15. Similarly, the increased hydrolytic activities against cephalosporins and sensitivity to β-lactamase inhibitors, clavulanic acid and sulbactam, of CTX-M-64 were partly due to the amino acids that were different from CTX-M-14 and located at both the C and N termini of CTX-M-64. These data indicate that residues distal to the active site of CTX-Ms contributed to their enhanced catalytic activities to ESCs.     

Ministry of Health Clinical Practice Guidelines: Anxiety Disorders

The Ministry of Health (MOH) has developed the clinical practice guidelines on Anxiety Disorders to provide doctors and patients in Singapore with evidence-based treatment for anxiety disorders. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the MOH clinical practice guidelines on anxiety disorders, for the information of SMJ readers. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website: http://www.moh.gov.sg/content/moh_web/healthprofessionalsportal/doctors/guidelines/cpg_medical.html. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

1.1 Background information

Anxiety disorders are known to be one of the most prevalent of psychiatric conditions, yet they often remain under-diagnosed and under-treated. Their chronic, disabling symptoms cause considerable burden not only to sufferers but also to their families, and contribute to poorer quality of life and considerable economic burden on society.In many instances, there is a delay in seeking treatment and in some cases such delay may stretch up to nearly ten years. This may result from ignorance of the condition, fear of taking medications, and the stigma of receiving a psychiatric diagnosis, and or having to accept psychiatric treatment.The anxiety disorders include panic disorder with or without agoraphobia, social anxiety disorder, specific phobia, obsessive-compulsive disorder, generalised anxiety disorder, acute stress disorder and post-traumatic stress disorder. In the clinical evaluation of anxiety disorders, it is important to ascertain the type of anxiety disorder present. This would allow treatment to be targeted at the specific type of disorder.These guidelines are developed to provide practical, evidence-based recommendations to primary care physicians and specialists in psychiatry for the diagnosis and management of the anxiety disorders.The first edition of the guidelines was published in 2003. In this edition, we present data from newer research as well as older data not previously reported in the earlier guidelines.For example, we examine the efficacy of combining medications with psychological therapy over medications alone, or psychological therapy alone. In view of the majority of anxiety sufferers being female we have made recommendations for pharmacotherapy during pregnancy and breastfeeding. As these guidelines are intended for use in the Singapore context, we have omitted treatments that are currently not available in Singapore.

1.2 Aim

These guidelines are developed to facilitate the diagnosis and assessment of the anxiety disorders, and to ensure that their management is appropriate and effective.

1.3 Scope

These guidelines will cover the management of anxiety disorders in adults and address the issues of medication use during pregnancy and breastfeeding.

1.4 Target group

The content of the guidelines will be useful for all doctors treating patients with anxiety disorders. Efforts have been made to ensure that the guidelines are particularly useful for primary care physicians and specialists in psychiatry, including all those involved in the assessment and management of patients with anxiety disorders in the community. The doctor treating the patient is ultimately responsible for clinical decisions made after reviewing the individual patient’s history, clinical presentation and treatment options available.

1.5 Development of guidelines

These guidelines have been produced by a committee of psychiatrists, a clinical psychologist, pharmacist, patient representative, and family practitioners appointed by the Ministry of Health. They were developed by revising the existing guidelines, reviewing relevant literature, including overseas clinical practice guidelines, and by expert clinical consensus of professionals with experience in treating patients in the local setting.The following principles underlie the development of these guidelines:

• Treatment recommendations are supported by scientific evidence whenever possible (randomised controlled clinical trials represent the highest level of evidence) and expert clinical consensus is used when such data are lacking.
• Treatment should maximise therapeutic benefits and minimise side effects.

1.6 What’s new in the revised guidelines

This edition of the guidelines contains updated recommendations based on latest evidence, as well as detailed discussions and recommendations on the management of anxiety disorders in adult populations.The following represent changes to the revised guidelines

• An extensive review of the literature, including new evidence. This involved the re-writing and extensive revision of the chapters.
• Length of treatment, which provides answers to a pertinent question.
• Use of medications during pregnancy and breastfeeding. Given that females are more likely to be at risk of being diagnosed with anxiety disorders, this is an important subject.

We are aware that the Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) was released in 2013. In DSM-5, post-traumatic stress disorder and obsessive-compulsive disorder have been removed and classified separately from the rest of the anxiety disorders. If we were to adhere strictly to DSM-5, this would entail omitting discussion on post-traumatic stress disorder and obsessive-compulsive disorder. As it is our aim to provide an update on the 2003 guidelines, post-traumatic stress disorder and obsessive-compulsive disorder have been included in this edition of the guidelines.In addition, anxiety conditions in children are included in DSM-5. Since the present guidelines are meant to address only adult anxiety disorders, guidelines on children’s anxiety conditions are not included here.Hence, for purposes of these guidelines, we will continue to use classifications based on the International Classification of Diseases-10 (ICD-10) and DSM-IV-TR criteria.

1.7 Review of guidelines

Evidence-based clinical practice guidelines are only as current as the evidence that supports them. Users must keep in mind that new evidence could supersede recommendations in these guidelines. The workgroup advises that these guidelines be scheduled for review five years after publication, or when new evidence appears that requires substantive changes to the present recommendations.     

Comparison of total hip and knee joint replacement in patients with rheumatoid arthritis and osteoarthritis: a nationwide,population-based study

INTRODUCTION

Patients with rheumatoid arthritis (RA) and osteoarthritis (OA) may require total hip replacement (THR) or total knee replacement (TKR). The present study aimed to compare the demographic characteristics and medical costs of RA and OA patients from Taiwan who underwent either THR or TKR.

METHODS

The medical records of patients who had undergone THR or TKR from 1 January 1996 to 31 December 2010 were obtained from the Taiwan National Health Insurance Research Database (NHIRD). In all, we found 49 and 146 RA patients who received THR and TKR, respectively, and 1,191 and 6,574 OA patients who received THR and TKR, respectively. The gender, age, Charlson comorbidity index (CCI), hospital grade, age at registration in the catastrophic illness dataset, and medical utilisation costs of the different groups were compared.

RESULTS

There were statistically significant differences in age, CCI score, drug costs and surgery costs between RA and OA patients. Joint replacement incidence was lower in RA patients than in OA patients, and among patients who underwent THR, total medical costs incurred were higher for RA patients than OA patients. RA patients who underwent THR incurred a significantly greater total medical utilisation cost in the outpatient department (3 months before surgery and 12 months after surgery) than OA patients who underwent THR.

CONCLUSION

Analysis of Taiwan NHIRD with regard to patients who had undergone either THR or TKR indicated that RA patients were younger than OA patients, and that significantly more medical resources were used for RA patients before, during and after hospitalisation for these procedures.