Foaming: Consequences, prevention and destruction

This review examines the significance of foaming in bioprocesses, the mechanics of foam formation and destruction, and the methods of foam control and suppression. Emphasis is given to chemical antifoaming agents and characterization of their efficiencies. Criteria for selecting antifoaming agents are discussed.     

Alzheimer neurofibrillary degeneration: significance, etiopathogenesis, therapeutics and prevention

Alzheimer disease (AD) is multi-factorial and heterogeneous. Independent of the aetiology, this disease is characterized clinically by chronic and progressive dementia and histopathologically by neurofibrillary degeneration of abnormally hyperphosphorylated tau seen as intraneuronal neurofibrillary tangles, neuropil threads and dystrophic neurites, and by neuritic (senile) plaques of beta-amyloid. The neurofibrillary degeneration is apparently required for the clinical expression of AD, and in related tauopathies it leads to dementia in the absence of amyloid plaques. While normal tau promotes assembly and stabilizes microtubules, the abnormally hyperphosphorylated tau sequesters normal tau, MAP1 and MAP2, and disrupts microtubules. The abnormal hyperphosphorylation of tau also promotes its self-assembly into tangles of paired helical and or straight filaments. Tau is phosphorylated by a number of protein kinases. Glycogen synthase kinase-3 (GSK-3) and cyclin dependent protein kinase 5 (cdk5) are among the kinases most implicated in the abnormal hyperphosphorylation of tau. Among the phosphatases which regulate the phosphorylation of tau, protein phosphatase-2A (PP-2A), the activity of which is down-regulated in AD brain, is by far the major enzyme. The inhibition of abnormal hyperphosphorylation of tau is one of the most promising therapeutic targets for the development of disease modifying drugs. A great advantage of inhibiting neurofibrillary degeneration is that it can be monitored by evaluating the levels of total tau and tau phosphorylated at various known abnormally hyperphosphorylated sites in the cerebrospinal fluid of patients, obtained by lumbar puncture. There are at least five subgroups of AD, each is probably caused by a different etiopathogenic mechanism. The AD subgroup identification of patients can help increase the success of clinical trials and the development of specific and potent disease modifying drugs.     

Niacin in cardiovascular prevention: mechanisms, efficacy, and safety

PURPOSE OF REVIEW: This review describes niacin's mechanism of action, efficacy in cardiovascular prevention, and safety. RECENT FINDINGS: A G-protein-coupled receptor [GPR109A/HM74A, mouse PUMA-G (protein upregulated in macrophages by interferon-gamma)] was found to mediate the antilipolytic effect of niacin via inhibition of adenylyl cyclase in adipocytes. The same receptor in skin Langerhans cells mediates the common flushing side effect. The endogenous ligand for the receptor may be beta-hydroxybutyrate. Among nine controlled clinical trials using niacin, mostly combined with other drugs, statistically significant positive impact on clinical or anatomic cardiovascular end-points was found in seven, which represents a remarkably consistent record of benefit. Although niacin induces insulin resistance, deterioration of glycemic control in diabetes is usually minor, and there is no evidence of increased incidence of new onset diabetes. Hepatic toxicity is common with higher doses of sustained-release niacin but rare with immediate-release and extended-release niacin at doses up to 2000 mg/day. Extended-release and immediate-release niacin do not substantially potentiate myopathic effects when given in combination with statins. SUMMARY: Recently developed understanding of the mechanisms, efficacy, and safety of niacin, along with progress in reducing the chief side effect of flushing, should enhance the use of this valuable agent for cardiovascular prevention.     

Recurrent diabetic ketoacidosis: causes, prevention and management

Longitudinal studies indicate that 20% of paediatric patients account for 80% of all admissions for diabetic ketoacidosis (DKA). The frequency of DKA peaks during adolescence and, although individuals generally go into remission, they may continue to have bouts of recurrent DKA in adulthood. The evidence for insulin omission being the behavioural precursor to recurrent DKA is reviewed and discussed. Thereafter the range of possible psychosocial causes is explored and the evidence for each discussed. Approaches to assessing the individual and their family to identify aetiology and therefore appropriate intervention are considered and treatment options reviewed. Finally, the paper examines potential risk factors for recurrent DKA, possible strategies for identifying these early and how to use these assessments to prevent subsequent recurrent DKA.     

Self-medication and antibiotic resistance: Crisis,current challenges,and prevention

The present study aims to explore the crisis of antibiotic resistance and discover more about the current challenges related to self-medication. The current challenges related to antibiotic resistance are unique and differ from the challenges of the past since new bacterial pathogens are involved and continue to evolve. Strains with resistance to multiple antibiotic classes have emerged which the discovery of new antibiotics has failed to match. The consequences of antibiotic resistance are grave with mortality and morbidity continually on the rise. This paper also highlights the possible interventions that can be effective at the micro or individual level in the prevention of development of antibiotic resistance.     

Stroke: development, prevention and treatment with peptidase inhibitors

Stroke is the leading cause of long-term disability in the United States and affects more people than any other neurologic disorder. Hypertension is a major risk factor associated with stroke. Several anti-hypertensive agents have been used to treat chronic hypertension to reduce the morbidity and mortality of stroke. Previous experimental studies have shown reduced stroke mortality with angiotensin-converting enzyme (ACE) inhibitors. This review discusses the development of stroke and potential use of ACE inhibitors in prevention and treatment of this disease. Furthermore, this review focuses on current investigations aimed at cellular mechanisms involved in stroke-induced microvascular alterations.     

Antituberculosis drug-induced hepatitis: risk factors, prevention and management

Apart from infectious or viral hepatitis, other most common non-infectious causes of hepatitis are alcohol, cholestatic, drugs and toxic materials. The most common mode that leads to liver injuries is antituberculosis drug-induced hepatitis. The severity of drug-induced liver injury varies from minor nonspecific changes in hepatic structure to fulminant hepatic failure, cirrhosis and liver cancer. Patients receiving antitubercular drug frequently develop acute or chronic hepatitis. The time required for the metabolites to reach hepatotoxic levels is much earlier with isoniazid plus rifampicin treatment than isoniazid alone and this has been shown to be synergistic rather than additive. Antituberculosis drug (ATT)-inducible cytochrome P-4502E1 (CYP2E1) is constitutively expressed in the liver. Recent studies show that polymorphism of the N-acetyltransferase 2 (NAT2) genes and glutathione-S-transferase (GST) are the major susceptibility risk factors for ATT-induced hepatitis. The hepatic NAT and GST are involved in the metabolism of several carcinogenic arylamines and drugs. The NAT2 enzyme has a genetic polymorphism in human. N-acetyltransferase 2 genes (NAT2) have been identified to be responsible for genetic polymorphism of slow and rapid acetylation in humans. Slow acetylators of NAT2 prove to develop more severe hepatotoxicity than rapid acetylators making it a significant risk factor. Deficiency of GST activity, because of homozygous null mutations at GSTM1 and GSTT1 loci, may modulate susceptibility to drug and xenobiotic-induced hepatotoxicity. Polymorphisms at GSTM1, GSTT1 and NAT2 loci had been linked to various forms of liver injury, including hepatocellular carcinoma.     

Suppurative chondritis: its incidence, prevention, and treatment in burn patients

A retrospective study of 317 cases of suppurative otochondritis occurring in a population of 4794 burned patients successively admitted to one institution between 1967 and 1984 is presented. During the study interval, the incidence of the disease decreased from 20 percent to less than 3 percent in patients with burns of one or both ears. The bacterial species associated with chondritis, principally Pseudomonas aeruginosa and Staphylococcus species, did not change. Patients admitted later than the second postburn day exhibited a significantly greater incidence of chondritis. The crucial factors in prevention of this complication appear to be avoidance of pressure on burned ears and topical chemotherapeutic control of local Pseudomonas infection. Systemic antibiotic prophylaxis did not appear to influence the incidence in the studied population. Several approaches to clinical management of suppurative chondritis are reviewed.     

Adolescent mothers, stress, and prevention

Adolescent mothers face problems that can lead to psychological stress. Based on prospective data from the present study, these problems point toward the need for a coping skills prevention approach to help adolescent mothers manage stress. This paper reports data from outcome research on such an approach with adolescent mothers. Subjects were 79 adolescent mothers who were tested before, immediately after, and three months following the provision of coping skills intervention in an experimental condition. Subjects in a test-only control condition received no special intervention. At posttest, experimental condition subjects showed more positive outcomes on measures of social support, cognitive performance, conflict management, and interpersonal competence. At three-month follow-up, experimental condition subjects had more positive outcomes on social support, cognitive performance, parenting ability, child care self-efficacy, and measures of psychological well-being.