Modeling the volume of tissue activated in deep brain stimulation and its clinical influence: a review

Deep brain stimulation (DBS) is a neuromodulatory therapy that has been FDA approved for the treatment of various disorders, including but not limited to, movement disorders (e.g., Parkinson's disease and essential tremor), epilepsy, and obsessive-compulsive disorder. Computational methods for estimating the volume of tissue activated (VTA), coupled with brain imaging techniques, form the basis of models that are being generated from retrospective clinical studies for predicting DBS patient outcomes. For instance, VTA models are used to generate target-and network-based probabilistic stimulation maps that play a crucial role in predicting DBS treatment outcomes. This review defines the methods for calculation of tissue activation (or modulation) including ones that use heuristic and clinically derived estimates and more computationally involved ones that rely on finite-element methods and biophysical axon models. We define model parameters and provide a comparison of commercial, open-source, and academic simulation platforms available for integrated neuroimaging and neural activation prediction. In addition, we review clinical studies that use these modeling methods as a function of disease. By describing the tissue-activation modeling methods and highlighting their application in clinical studies, we provide the neural engineering and clinical neuromodulation communities with perspectives that may influence the adoption of modeling methods for future DBS studies.

Intranasal SARS-CoV-2 RBD decorated nanoparticle vaccine enhances viral clearance in the Syrian hamster model

Multiple vaccines have been developed and licensed for SARS-CoV-2. While these vaccines reduce disease severity, they do not prevent infection, and SARS-CoV-2 continues to spread and evolve. To prevent infection and limit transmission, vaccines must be developed that induce immunity in the respiratory tract. Therefore, we performed proof-of-principle vaccination studies with an intranasal nanoparticle vaccine against SARS-CoV-2. The vaccine candidate consisted of the self-assembling 60-subunit I3-01 protein scaffold covalently decorated with the SARS-CoV-2 receptor binding domain (RBD) using the SpyCatcher-SpyTag system. We verified the intended antigen display features by reconstructing the I3-01 scaffold to 3.4A using cryo-EM, and then demonstrated that the scaffold was highly saturated when grafted with RBD. Using this RBD-grafted SpyCage scaffold (RBD+SpyCage), we performed two unadjuvanted intranasal vaccination studies in the "gold-standard" preclinical Syrian hamster model. Hamsters received two vaccinations 28 days apart, and were then challenged 28 days post-boost with SARS-CoV-2. The initial study focused on assessing the immunogenicity of RBD+SpyCage, which indicated that vaccination of hamsters induced a non-neutralizing antibody response that enhanced viral clearance but did not prevent infection. In an expanded study, we demonstrated that covalent bonding of RBD to the scaffold was required to induce an antibody response. Consistent with the initial study, animals vaccinated with RBD+SpyCage more rapidly cleared SARS-CoV-2 from both the upper and lower respiratory tract. These findings demonstrate the intranasal SpyCage vaccine platform can induce protection against SARS-CoV-2 and, with additional modifications to improve immunogenicity, is a versatile platform for the development of intranasal vaccines targeting respiratory pathogens.

Filgrastim-Associated Pneumonitis in Cancer Patient Undergoing Hematopoietic Stem Cell (HSC) Mobilization for Autologous-HSC Transplantation

Filgrastim is a granulocyte-colony stimulating factors (G-CSF) used for multiple indications in cancer patients. We present a case of a 65-year-old man with non-Hodgkin’s lymphoma who was undergoing mobilization of hemopoietic stem cells for autologous-hematopoietic stem cell transplantation (auto-HSCT) with filgrastim who developed dyspnea and non-productive cough. Chest imaging showed left lower lobe consolidation, new ground-glass opacities and small right-sided pleural effusion. Bronchoscopy with bronchoalveolar lavage (BAL) and infectious evaluation were completely negative. He was admitted for further evaluation and management. Antibiotics weren’t started immediately given the clinical stability, multiple probable causes of fever and the intent of not confounding future thoracentesis results with antibiotic use. Thoracentesis occurred draining serous exudative pleural fluid; with follow-up chest imaging demonstrating no re-accumulation. His symptoms resolved and he was discharged in stable condition. The symptoms were hypothesized to be the probable adverse effects of filgrastim. We suggest close monitoring of pulmonary toxicities while administering this drug to patients to minimize such complications.

Direct 24-Hour Presumptive Enumeration of Escherichia coli 0157:H7 in Foods Using Hydrophobic Grid Membrane Filter Followed by Serological Confirmation: Collaborative Study

Fifteen laboratories took part in a collaborative study to validate a method for enumerating Escherichia coli 0157:H7. The method is based on use of a hydrophobic grid membrane filter and consists of 24 h presumptive enumeration on SD-39 Agar and serological confirmation to yield a confirmed E. coli 0157:H7 count. Six food products were analyzed: pasteurized apple cider, pasteurized 2% milk, cottage cheese, cooked ground pork, raw ground beef, and frozen whole egg. The test method produced significantly higher confirmed count results than did the reference method for milk, pork, and beef. Test method results were numerically higher than but statistically equivalent to reference method results for cheese, cider, and egg. The test method produced lower repeatability and reproducibility values than did the reference method for most food/inoculation level combinations and values very similar to those of the reference method for the remaining combinations. Overall, 94% of presumptive positive isolates from the test method were confirmed serologically as E. coli 0157:H7, and 98% of these were also biochemically typical of E. coli 0157:H7 (completed test). Corresponding rates for the reference method were 69 and 98%, respectively. On the basis of the results of this collaborative study and the precollaborative study that preceded it, it is recommended that this method be adopted official first action for enumeration of E. coli 0157:H7 in meats, poultry, dairy foods, infant formula, liquid eggs, mayonnaise, and apple cider

In vivo measurement of the surface energy of human fingernail plates

The surface energy of the human nail plate is expected to influence the adhesion of microorganisms (and subsequent colonization and infections) as well as that of medicines (and subsequent drug permeation) and of cosmetics. The aim of the study was therefore to measure the surface energy of nail plates in vivo. The surface energy of healthy human fingernails (untreated, hydrated and abraded) and of hoof membranes (often used as a model for the nail plate) was estimated from contact angle measurements of liquids (water, formamide, diiodomethane and glycerol) on the nail plate and subsequent computation using the Lifshitz-van der Waals/acid-base (LW-AB) approach. The surface energy of untreated fingernail plates was found to be 34 mJ m(-2) . Most of this total energy was from the apolar Lifshitz-van der Waals component. When the polar component of the surface energy was analysed, the electron donor component was considerably larger than the electron acceptor one. Hydrating the nail plate had no significant influence on the surface energy. In contrast, abrasion caused a small, but statistically significant increase in the apolar surface energy component. The surface energy of bovine hoof membrane was similar to that of the fingernail plate. We conclude that the human fingernail plate is a low-energy surface and that bovine hoof membranes may be used as a substitute for the nail plate in certain experiments.

Stability-indicating Simultaneous HPTLC Method for Olanzapine and Fluoxetine in Combined Tablet Dosage Form

A rapid, selective and stability-indicating high performance thin layer chromatographic method was developed and validated for the simultaneous estimation of olanzapine and fluoxetine in combined tablet dosage form. Olanzapine and fluoxetine were chromatographed on silica gel 60 F₂₅₄ TLC plate using methanol:toluene (4:2 v/v) as the mobile phase and spectrodensitometric scanning-integration was performed at a wavelength of 233 nm using a Camag TLC Scanner III. This system was found to give compact spots for both olanzapine (R_f value of 0.63±0.01) and fluoxetine (R_f value of 0.31±0.01). The polynomial regression data for the calibration plots showed good linear relationship with r²=0.9995 in the concentration range of 100-800 ng/spot for olanzapine and 1000-8000 ng/spot for fluoxetine with r²=0.9991. The method was validated in terms of linearity, accuracy, precision, recovery and specificity. The limit of detection and the limit of quantification for the olanzapine were found to be 30 and 100 ng/spot, respectively and for fluoxetine 300 and 1000 ng/spot, respectively. Olanzapine and fluoxetine were degraded under acidic, basic and oxidation degradation conditions which showed all the peaks of degraded product were well resolved from the active pharmaceutical ingredient. Both drugs were not further degraded after thermal and photochemical degradation. The method was found to be reproducible and selective for the simultaneous estimation of olanzapine and fluoxetine. As the method could effectively separate the drugs from their degradation products, it can be employed as a stability-indicating method.

Psychosomatic disorders in pediatrics

Psychosomatic symptoms are by definition clinical symptoms with no underlying organic pathology. Common symptoms seen in pediatric age group include abdominal pain, headaches, chest pain, fatigue, limb pain, back pain, worry about health and difficulty breathing. These, more frequently seen symptoms should be differentiated from somatoform or neurotic disorders seen mainly in adults. The prevalence of psychosomatic complaints in children and adolescents has been reported to be between 10 and 25%. These symptoms are theorized to be a response to stress. Potential sources of stress in children and adolescents include schoolwork, family problems, peer pressure, chronic disease or disability in parents, family moves, psychiatric disorder in parents and poor coping abilities. Characteristics that favour psychosomatic basis for symptoms include vagueness of symptoms, varying intensity, inconsistent nature and pattern of symptoms, presence of multiple symptoms at the same time, chronic course with apparent good health, delay in seeking medical care, and lack of concern on the part of the patient. A thorough medical and psychosocial history and physical examination are the most valuable aspects of diagnostic evaluation. Organic etiology for the symptoms must be ruled out. Appropriate mental health consultation should be considered for further evaluation and treatment.

Calcium-dependent binding of annexin 12 to phospholipid bilayers: stoichiometry and implications

Annexins (ANXs) are a superfamily of proteins whose functional hallmark is Ca2+-dependent binding to anionic phospholipids. Their core domains are usually composed of a 4-fold repeat of a conserved amino acid sequence, with each repeat containing a type II Ca2+ binding site that is generally thought to mediate Ca2+-dependent binding to the membrane. We now report that ANX12 binding to phospholipid vesicles is highly cooperative with respect to Ca2+ concentration (Hill constant approximately 7), thereby suggesting that more than the four well-characterized type II Ca2+ binding sites are involved in phospholipid binding. Two independent approaches, a novel 45Ca2+ copelleting assay and isothermal titration calorimetry, indicate a stoichiometry of approximately 12 mol of Ca2+/mol of ANX12 for binding to phospholipid vesicles. On the basis of the "low-affinity" Ca2+-binding sites in a number of ANX X-ray crystal structures, we propose a model for ANX12 bilayer binding that involves three types of Ca2+ sites in each of the four repeats. In this model, there is a complementarity between the spacing of the ANX12 Ca2+ binding sites and the spacing of the phospholipid headgroups in bilayers. We tested the implications of the model by manipulating the physical state of vesicles composed of phospholipids with saturated acyl chains with temperature and measuring its influence on ANX12 binding. ANX12 bound to vesicles in a Ca2+-dependent manner when the vesicles were in the liquid crystal phase but not when the phospholipid was in the gel phase. Furthermore, ANX12 bound initially to fluid bilayers remained bound when cooled to 4 degrees C, a temperature that should induce the gel phase transition. Overall, these studies suggest that ANX12 is well suited to being a Ca2+ sensor for rapid all-or-none intercellular membrane-related events.

Presynaptic alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor-mediated stimulation of glutamate and GABA release in the rat striatum in vivo: a dual-label microdialysis study

The existence of presynaptic alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA)-type glutamate autoreceptors on glutamate nerve terminals in vitro has recently been demonstrated using synaptosomal and brain slice preparations. In the present study we have used a modification of a rapid dual-label intracerebral microdialysis method, previously developed by Young and co-workers(80,81) for the study of presynaptic mechanisms of neurotransmitter release, to investigate whether presynaptic AMPA receptors also play a role in the control of striatal glutamate release in vivo. For comparative purposes, the action of locally applied AMPA on striatal GABA release in vivo was also monitored. Local application of AMPA (0.01-100 microM), by reverse dialysis, into the striatum resulted in concentration-dependent increases in the Ca(2+)-dependent efflux of both [3H]L-glutamate and [14C]GABA. Maximum responses reached 142.0+/-6.5% and 166.8+/-7.7% of basal efflux for [3H]L-glutamate and [14C]GABA, respectively. No marked behavioural changes were observed at any dose of the agonist. Unexpectedly, the AMPA-evoked responses were not potentiated by the AMPA receptor desensitization inhibitors cyclothiazide (10-100microM) or aniracetam (1mM). Consistent with this finding, AMPA-stimulated [3H]L-glutamate and [14C]GABA efflux were significantly attenuated by co-perfusion with the selective, competitive AMPA receptor antagonist 6-nitro-7-sulphamoylbenzo(F)quinoxaline-2,3-dione (100microM) but not 1-(aminophenyl)-4-methyl-7,8-methylendioxy-5H-2,3-benzodiazepine (100microM), a non-competitive AMPA receptor antagonist known to interact with the cyclothiazide site to control AMPA receptor function. The broad spectrum ionotropic glutamate receptor antagonist, kynurenic acid (100-1000microM) also markedly inhibited the AMPA-evoked responses in the striatum in vivo. None of the antagonists, when given alone, influenced basal efflux of [3H]L-glutamate suggesting a lack of tonic regulatory control of glutamate release via presynaptic AMPA-type autoreceptors in the rat striatum. These results demonstrate the presence of presynaptic AMPA receptors, of a novel cyclothiazide- and aniracetam-insensitive subtype, on presynaptic nerve terminals in the rat striatum in vivo, acting to enhance glutamate and GABA release. Our data support the concept of AMPA receptor heterogeneity in vivo, a finding which may facilitate the development of novel, more selective drugs for the treatment of a range of neurological disorders associated with abnormal cerebral glutamate release. The pharmacological profile of these novel presynaptic receptors is currently under investigation.

Contraception in the adolescent: an update

Contraception remains an important part of national efforts to reduce adolescent pregnancy in the United States. A number of safe and effective contraceptive methods are available for our youth, including abstinence, barrier methods, oral contraceptives, Depo-Provera, and Norplant. Research over the past few decades has resulted in a variety of oral contraceptives with reduced amounts of hormones and reduced side-effects. A number of methods have received approval by the Food and Drug Administration since the last review in 1980, including emergency contraceptives, depomedroxyprogesterone acetate, and the cervical cap. The use of condoms and vaginal spermicides continues to be recommended for all sexually active adolescents to reduce (not eliminate) the risk for acquiring sexually transmitted diseases. A polyurethane condom is now available, in addition to the latex condom and other barrier contraceptives, including the following: diaphragm, cervical cap, vaginal sponge, female condom and vaginal spermicides. Because of continuing concerns about pelvic inflammatory disease related to intrauterine devices, currently available intrauterine devices are not recommended for most adolescents. Abortion is not considered as a contraceptive method.

Recent advances in the hearing assessment of children

The remarkable specificity and sensitivity of otoacoustic emissions (OAEs) in identifying cochlear dysfunction, and the speed and objectivity with which the test can be conducted has made the OAE procedure the 'standard-of-care' in pediatric audiology assessment. Together with the auditory brainstem responses (ABRs), the OAE procedure not only separates sensory from neural impairment, but also facilitates early audiologic diagnosis and management. This article describes some unique applications of the OAE procedure in the diagnosis, monitoring and treatment of auditory dysfunction.

Treatment of attention-deficit hyperactivity disorder

Attention-deficit hyperactivity disorder (ADHD) is a common disorder among children and adolescents with reported prevalence rates of between 3 and 10%. Recent reports suggest that a multimodal treatment approach is preferable to address many symptoms of ADHD and its associated problems for the children, the family, and the school. Stimulant medications remain the mainstay of treatment and are highly effective in more than 75% of patients. Improvement in the core symptoms of inattention, impulsivity, and hyperactivity are most noticeable. Recently approved extended release preparation of methylphenidate will allow once a day dosing. Reports of effectiveness of some non-stimulant medications such as bupropion, especially for adolescents, appear promising. A number of behavioral and psychosocial interventions can be used effectively as part of multimodal approach to address many ADHD-related problems. This article provides an update on practical information on the treatment of children and adolescents with ADHD who do not have other associated psychiatric disorders.

Office interventions for adolescent smokers

Smoking-prevention efforts can be undertaken at a national level, with enactment and enforcement of laws on the use of tobacco products by youth; at the state and local level, with involvement of community organizations; and through school systems, with education regarding the harmful effects of tobacco use. This review, however, focuses on the role of individual practitioners who also can make significant contributions by working at an individual level to incorporate prevention and treatment strategies in their daily medical practice. This article reviews two types of smoking cessation interventions-behavioral and pharmacologic. Currently available data on the prevention and treatment of nicotine addiction in adolescents, particularly pharmacotherapy, are quite limited. The individual clinician can contribute to prevention and treatment of tobacco use among children and adolescents by using many of the known behavioral and pharmacologic strategies.

Pulmonary effects of smoking

The problems of tobacco addiction have evolved over centuries. The possible relationship between smoking and oral cancer was recognized as early as the 19th century. The use of tobacco results in an estimated 4 million deaths each year worldwide. Approximately 3,000 adolescents start smoking every day; 4.5 million children and adolescents smoke cigarettes; 1 million use smokeless tobacco. This article reviews the effects of environmental tobacco smoke and primary smoking on lung health and maturation and the pathophysiology of smoking-related pulmonary disease. Smoking prevention and timely smoking cessation will significantly reduce the risk of not only lung diseases (chronic obstructive pulmonary disease, cancer, chronic bronchitis, asthma, etc.) but also suboptimal lung growth during preadolescent and adolescent years.

Sports injuries in adolescents

Musculoskeletal injuries are the most common injuries in youth sports. A number of growth-related factors unique to the adolescent age group play an important role in the epidemiology, types, and management of these injuries. These mainly relate to the physical and psychosocial growth and development during adolescence and are discussed in this article. Overuse injuries are more commonly seen in this age group in the primary care setting. Shoulder impingement, elbow and shoulder injuries related to throwing, stress injuries of the wrist, spondylolysis, and anterior knee pain are some of the overuse injuries reviewed in this article.

Sports related mild traumatic brain injury in adolescents

While head injuries are not common in youth sports, they may have catastrophic results. Concussion is also referred to as mild traumatic brain injury (MTBI). Although the occurrence of head injuries has been studied more extensively in American football, the findings have wider application for any MTBI. Recently, more attention has been directed at other sports in which both boys and girls participate. The diagnosis of MTBI is based on subjective findings and subtle changes in mental status. Other cerebral injuries requiring emergent or urgent neurosurgical attention should be ruled out. Objective tests such as CT scans and Magnetic Resonance Imaging (MRI) are usually without significant findings in MTBI. Neuropsychological testing may demonstrate areas of deficiencies, however, results may be difficult to interpret because of confounding factors. Complications following MTBI have been known to occur. The most catastrophic of these is second impact syndrome. There are a variety of guidelines for return to play following a concussion, which have been designed in an effort to avoid problems such as second impact syndrome. These guidelines are based more on clinical experience than on scientific evidence. Education, good training and coaching techniques, improved equipment, and rule changes and enforcement, can all help in curbing the sports related head injuries in adolescents.

Annexins V and XII insert into bilayers at mildly acidic pH and form ion channels

The functional hallmark of annexins is the ability to bind to the surface of phospholipid membranes in a reversible, Ca(2+)-dependent manner. We now report that human annexin V and hydra annexin XII reversibly bound to phospholipid vesicles in the absence of Ca(2+) at low pH; half-maximal vesicle association occurred at pH 5.3 and 5. 8, respectively. The following biochemical data support the hypothesis that these annexins insert into bilayers at mildly acidic pH. First, a photoactivatable reagent (3-trifluoromethyl)-3-(m-[(125)I]iodophenyl)diazirine) which selectively labels proteins exposed to the hydrophobic domain of bilayers reacted with these annexins at pH 5.0 and below but not at neutral pH. Second, in a Triton X-114 partitioning assay, annexins V and XII act as integral membrane proteins at low pH and as hydrophilic proteins at neutral pH; in the presence of phospholipids half-maximal partitioning into detergent occurred at pH approximately 5.0. Finally, annexin V or XII formed single channels in phospholipid bilayers at low pH but not at neutral pH. A model is discussed in which the concentrations of H(+) and Ca(2+) regulate the reversible conversion of three forms of annexins-soluble, peripheral membrane, and transmembrane.

Sport participation, risk taking, and health risk behaviors

Adolescents participate in sports for a variety of reasons. Some seem to enjoy participating in what some might consider very-high-risk or "extreme" sports activities. For some adolescents risk taking becomes pervasive and can be detrimental to normal health and development. The majority of adolescents will do well in the context of athletics, and the many positive benefits of regular physical activity and sports participation should be appropriately emphasized. However, a subset of adolescents may be at greater risk for adverse consequences. This article reviews the reasons for participation and attrition from sports, the phenomenon of thrill seeking in sports, certain risk-taking behaviors of athletes, and studies comparing health risk behaviors in athletes and non-athletes.

Romance with the automobile in the 20th century: implications for adolescents in a new millennium

Nearly three-fourths of deaths among American adolescents and young adults result from only four causes: motor vehicle accidents, other unintentional injuries, homicide, and suicide. Thirty percent of those deaths result from motor vehicle accidents, the number one cause of death among adolescents. A number of factors that influence the morbidity and mortality are associated with driving. Compared to other countries, it is easier for American adolescent to obtain a relatively inexpensive license and gain access to a car. For the young driver, adolescent development and increased risk taking, inexperience, dangerous driving behavior, and alcohol-related factors are of special significance. In this article, we review recent crash statistics as well as effectiveness of various preventive measures, including driver education, graduated licensing, alcohol-related measures, and vehicle-related factors. Graduated licensing and alcohol-related measures have been the most effective measures so far.

Annexin 5 mediates a peroxide-induced Ca(2+) influx in B cells

Annexin 5 is a Ca(2+)-binding protein, the function of which is poorly understood. Structural and electrophysiological studies have shown that annexin 5 can mediate Ca(2+) fluxes across phospholipid membranes in vitro [1]. There is, however, no direct evidence for the existence of annexin 5 Ca(2+) channels in living cells. Here, we show that annexin 5 inserts into phospholipid vesicle membranes at neutral pH in the presence of peroxide. We then used targeted gene disruption to explore the role of annexin 5 in peroxide-induced Ca(2+) signaling in DT40 pre-B cells. DT40 clones lacking annexin 5 exhibited normal Ca(2+) responses to both thapsigargin and B-cell receptor stimulation, but lacked the sustained phase of the response to peroxide. This late phase was due to Ca(2+) influx from the extracellular space, demonstrating that annexin 5 mediates a peroxide-induced Ca(2+) influx. Thus, peroxide induces annexin 5 membrane insertion in vitro, and peroxide-induced Ca(2+) entry in vivo in DT40 cells requires annexin 5. Our results are consistent with a role for annexin 5 either as a Ca(2+) channel, or as a signaling intermediate in the peroxide-induced Ca(2+)-influx pathway.

Smoking and children

Tobacco use by children and adolescents is a major health threat. A number of carcinogens and other harmful compounds have been identified in tobacco smoke. The major component, nicotine, is highly addictive. In India, approximately 5500 children and adolescents start using tobacco products daily, some as young as 10 years old. The majority of users have first tried tobacco prior to age 18. Children and adolescents are exposed to the harmful effects of nicotine from smoking or second hand smoke from others; and from use of smokeless tobacco. There is increased prevalence of respiratory disease, ear and sinus infections, asthma, oral disease, and many long-term complications such as cardiovascular disease and cancers due to tobacco use. Prevention and treatment strategies include behavioural approaches and pharmacotherapy. There is an increased urgency especially, for countries like India to address the problem of tobacco use by children and adolescents as the tobacco industry faces legal and public opinion obstacles in Western countries like United States. The medical practitioner can play an important role by implementing the preventive and treatment strategies in his or her practice.

Substance abuse: a pediatric concern

Use of alcohol, tobacco, and other drugs is a worldwide problem and affects many children and adolescents. The use of opiates, cannabis, tobacco, and alcohol have been well recognized for centuries in India. Abuse of alcohol is widespread in college campuses. In the United States, in 1997, 54.3% of high-school students had used an illicit drug by the time they entered 12th grade. In India the use of drugs and alcohol within the context of religious beliefs and local traditions has been historically documented. Children & adolescents are exposed to alcohol, cannabis products, and tobacco product. Several risk factors and protective factors have been identified. A screening psychosocial history is the most useful tool to identify non-specific indicators of substance abuse. In India the use of pan masala, and home brewed products containing marijuana and alcohol have special significance. Pan masala is shown to have carcinogenic, genotoxic, and clastogenic properties. The pediatrician can play a vital role in the appropriate recognition and early referral.

Medical evaluation of child abuse

Child abuse is a world-wide problem and has existed in all societies and cultures in various forms since ancient times. Intrafamilial physical and sexual abuse is well recognized in United States and other western countries. In countries like India there is a general lack of sensitivity to the issue among professionals and the lay public alike. The pressing issues of poverty, malnutrition, and infectious diseases take priority on resource allocation. Although some of the methods of child rearing and discipline may be culturally sanctioned and inherent, it does not necessarily mean they are harmless. In this paper the authors present clinical signs and symptoms of physical and sexual abuse which occur in the intrafamilial context and are of direct relevance to the medical practitioner.

Encopresis

Encopresis is fecal soiling associated with functional constipation in a child. Constipation and encopresis are common problems in children. Encopresis is most common between ages 3 and 7 years. Infants and pre-school children present with a history of constipation and withholding maneuvers. The school-age child may have constipation and fecal soiling for some time prior to detection. In some children encopresis is associated with enuresis and urinary tract infection. Family education is the essential first step in management, followed by disimpaction of stool and complete evacuation of the rectum. Reaccumulation of stool should be prevented by appropriate use of laxatives and stool softeners. This is followed by a gradual weaning of the laxative regimen and instituting toilet training. Relapses may occur. Up to 50-60% of children achieve acceptable bowel control, free of soiling, within a year.

Adolescent growth, development, and psychosocial aspects of sports participation: an overview

This chapter examines sports participation in the context of adolescent growth and development. Because the nature of sports participation is highly organized and competitive, it is imperative that parents, coaches, physicians, and other clinicians remember that they may be placing increased pressures on the adolescent to perform and practice. The authors review the impact of physical growth and psychosocial development and also describe how substance abuse, depression, and aggressive behavior may or may not be influenced by sports participation.

Diabetes mellitus and sports

The adolescent with insulin-dependent diabetes mellitus (IDDM) can safely participate in sports activities without interference from the disease. To ensure safe and successful participation, clinicians must appreciate how diabetes may alter the physiologic adaptation to strenuous exercise and how an individualized self-care plan can empower the adolescent with IDDM to effectively manage meal planning, blood glucose testing, and insulin injections. Various types of insulin, insulin schedules, and insulin delivery devices that may suit a wide variety of training and activity regimens are described.

The breast and sports: issues for the clinician

Although a number of recent reviews have focused on the effects of exercise and sports on menstrual function, minimal emphasis has been placed on how the breast is affected. Increasing numbers of female athletes are participating in previously male-dominated contact sports; the effect on overall breast health from medium-to-high impact activities remains to be seen. This article reviews the basic anatomy and embryology of breast tissue, outlines various problems of the breast that the adolescent athlete may encounter, and offers management strategies for such problems.

Eating disorders

Anorexia nervosa and bulimia nervosa are primarily psychiatric disorders characterized by severe disturbances of eating behaviour. Anorexia nervosa has been well documented in pre-pubertal children. Eating disorders are most prevalent in the Western cultures where food is in abundance and for females attractiveness is equated with thinness. Eating disorders are rare in countries like India. As Western sociocultural ideals become more widespread one may expect to see an increase in number of cases of eating disorders in non-Western societies. Etiological theories suggest a complex interaction among psychological, sociocultural, and biological factors. Patients with anorexia nervosa manifest weight loss, fear of becoming fat, and disturbances in how they experience their body weight and shape. Patients with bulimia nervosa present with recurrent episodes of binge eating and inappropriate methods of weight control such as self-induced vomiting, and abuse of diuretics and laxatives. Major complications of eating disorders include severe fluid and electrolyte disturbances and cardiac arrhythmias. The most common cause of death in anorexia nervosa is suicide. Management requires a team approach in which different professionals work together. Individual and family psychotherapy are effective in patients with anorexia nervosa and cognitive-behavioral therapy is effective in bulimia nervosa. Pharmacotherapy is not universally effective by itself. Patients with eating disorders suffer a chronic course of illness. The pediatrician plays important role in early diagnosis, management of medical complications, and psychological support to the patient and the family.

The rebellious adolescent. Evaluation and management of oppositional and conduct disorders

A wide variety of management options are available to the primary care physician who is presented with a rebellious adolescent. After a careful assessment, the clinician and other health care professionals can choose a diverse combination of interventions: individual therapy, family therapy, youth-centered programs, community-centered programs, psychopharmacology, and others. Rebellious adolescents need access to comprehensive medical and mental health care, academic education (including sexuality education), and full employment opportunities. Primary care physicians can play a vital and sometimes pivotal role coordinating services and helping parents, school personnel, and therapists work with these youth. Even when dealing with the very difficult and resistant group of youth with CD and ODD, optimism for improvement should always be maintained by the clinician.

Evidence for a role of presynaptic AMPA receptors in the control of neuronal glutamate release in the rat forebrain

The role of presynaptic alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in controlling the neuronal release of excitatory amino acids has been investigated. Stimulation of presynaptic AMPA receptors by the endogenous agonist L-glutamate, or by (R,S)-AMPA, dose-dependently enhanced the Ca(2+)-dependent, tetrodotoxin-insensitive, electrically-stimulated release of [3H]D-aspartate from rat forebrain slices. This AMPA receptor-mediated response showed marked stereoselectivity with the activity residing solely in the (S)-isomer. (R)-AMPA was inactive in this respect. AMPA-evoked responses were significantly enhanced in the presence of the AMPA receptor desensitization inhibitor, cyclothiazide (10 microM). Moreover, responses to both AMPA and glutamate were inhibited by competitive (NBQX) and non-competitive (GYKI 52466) AMPA receptor-selective antagonists in a dose-dependent manner. These results provide strong support for the existence of presynaptic AMPA receptors acting to enhance the synaptic release of excitatory amino acids in the mammalian forebrain. Such a positive feedback system may play an important functional role in physiological (e.g., long-term potentiation) and/or pathological (e.g., epileptogenesis) processes in the mammalian central nervous system. AMPA-type autoreceptors may provide new targets for drug action.

Molecular cloning and expression of a human secretin receptor

Secretin is a 27-amino acid neuroendocrine peptide that stimulates fluid and electrolyte secretion in the gastrointestinal tract, activates tyrosine hydroxylase activity in the central nervous system, and affects cardiac and renal function. Specific receptors for secretin have been previously characterized on neuroblastoma cells, pancreatic acini, gastric glands, and liver cholangiocytes. We report here the isolation of a 1616-base pair cDNA from human lung tissue that encodes a 440-amino acid, 50-kDa, G protein-coupled human secretin receptor (HSR), with homology of 80% with the rat secretin receptor and 37% with the human type I vasoactive intestinal peptide receptor. Northern blot analysis of human tissue mRNA revealed that the relative intensity for expression of a 2.1-kilobase HSR transcript was pancreas > kidney > small intestine > lung > liver, with trace levels in brain, heart, and ovary. Stable transfectants of HSR in human embryonic kidney 293 cells, termed 293S12, expressed 10(5) binding sites/cell for 125I-secretin, with an apparent Kd of 3.2 nM. Vasoactive intestinal peptide, pituitary adenylyl cyclase-activating peptide-38, and glucagon were less potent (by 3 orders of magnitude) than secretin in competitively inhibiting 125I-secretin binding to 293S12 cells. Secretin evoked concurrent dose-dependent increases in intracellular cAMP and calcium levels in 293S12 cells and stimulated a 4-fold increase in phosphatidylinositol hydrolysis. Thus, the HSR expressed by stable transfectants can couple to two distinct intracellular signaling pathways.

Human vasoactive intestinal peptide1 receptors expressed by stable transfectants couple to two distinct signaling pathways

Vasoactive intestinal peptide (VIP) is a potent neuropeptide mediator of central and peripheral nervous system function. A human VIP1 receptor (HVR) cDNA clone was previously obtained from HT29 intestinal epithelial cells and lung tissue. Stably-transfected human embryonic kidney 293 cells and chinese hamster ovary (CHO) cells expressing about 10(6) HVRs per cell that bind [125I]VIP with a Kd of 0.2-0.8 nM, and specifically recognized by anti-HVR antibodies, were established and characterized. VIP induced increases in intracellular cAMP levels ([cAMP]i) dose-dependently with an EC50 of 0.2 nM in 293 and CHO stable transfectants and concurrently evoked dose-dependent increases in intracellular calcium concentrations ([Ca2+]i), as determined by fluorescence-dye spectroscopy. Untransfected 293 and CHO cells showed minimal binding or intracellular effects of VIP; however, native VIP1 receptors of HT29 cells also increased [cAMP]i and [Ca2+]i in dose-dependent responses to VIP. Thus recombinant and native human VIP1 receptors both couple to two distinct signal transduction pathways within a single cell type.

Specific recognition of the human neuroendocrine receptor for vasoactive intestinal peptide by anti-peptide antibodies

Rabbit polyclonal IgG antibodies were generated to three distinct synthetic peptide substituents of the human neuroendocrine-type 7 transmembrane-domain receptor for vasoactive intestinal peptide (VIP), including a portion of the amino-terminus, first extracellular loop, and carboxyl-terminus. Immunofluorescent staining of both human K293 cell transfectants, expressing recombinant VIP receptors, and HT-29 human intestinal epithelial cells, bearing native VIP receptors, was observed with each of the antibodies and was eliminated specifically after absorption of antibodies with the respective peptide immunogen. Each of the antibodies recognized the same approximately 70-kDa membrane proteins, extracted from both K293 cell transfectants and HT-29 cells, in sodium dodecyl sulfate-polyacrylamide gel electrophoresis blots. Neither IgG nor Fab preparations of the antibodies inhibited VIP binding to cellular receptors at a concentration of 1 microgram/ml, that yielded optimal immunofluorescence, or at 5-300 micrograms/ml. In contrast, 5-200 micrograms/ml of anti-peptide antibodies as IgG, but not Fab, significantly inhibited the increase in concentration of cyclic AMP in HT-29 cells elicited by 1 nM VIP, without affecting the greater increase evoked by 100 nM VIP or alone altering the level of cyclic AMP. Antibodies to several peptide substituents thus bind specifically to VIP receptors in immunoblots and permeabilized cells, and may affect the cellular functions of VIP receptors with sufficient selectivity to reduce transduction of signals, without altering the binding of VIP.

Stem cell factor is a neurotrophic factor for neural crest-derived chick sensory neurons

We have found that stem cell factor (SCF) selectively enhances the survival of cultured embryonic chick dorsal root ganglia (DRG) neurons. Neurons grown in the presence of SCF expressed both neurofilament 150 kDa subunit and calcitonin-gene related peptide. SCF does not, however, enhance the survival of parasympathetic, placode-derived sensory or sympathetic neurons in culture. Combining SCF with brain-derived neurotrophic factor or neurotrophin-3, but not with NGF, maintains more neurons than either factor alone, suggesting that these factors have partially overlapping activities. SCF preferentially rescues small neurons from the DRG. Labeling studies with bromodeoxyuridine indicate that the neurons sustained by SCF are not differentiating from a dividing progenitor.

Cloning and functional expression of a human neuroendocrine vasoactive intestinal peptide receptor

Vasoactive intestinal peptide (VIP) is a potent mediator of gastrointestinal, nervous, pulmonary, vascular and immune functions. A cDNA was obtained from human HT29 intestinal epithelial cells and found to encode a 457 amino acid, 52 kDa VIP receptor. Transfection of the cDNA into COS-7 cells and 293 cells resulted in expression of specific saturable binding of VIP with a Kd of 0.8 nM, and induction of increases in intracellular cAMP by VIP with an EC50 of 1 nM. The human VIP receptor is homologous to other G protein-coupled receptors of the secretin-parathyroid hormone receptor family. A 2.8 kb transcript was detected in human lung, HT29 cells and Raji B-lymphoblasts with weaker expression in human brain, heart, kidney, liver and placenta.

The role of oriT in tra-dependent enhanced recombination between mini-F-lac-oriT and lambda plac5

Recombination between F42lac and lambda plac5 is typically 20- to 50-fold more efficient than recombination between chromosomal lac and lambda plac5. This enhancement of recombination is recBCD-dependent and requires the expression of genes from the tra regulon of the F factor. Also required is oriT, the origin of F factor conjugational transfer, which must be located in-cis to the cellular copy of lac. In this study we show that enhanced recombination is not supported by an oriT point mutant that reduces oriT function in conjugation. We also present evidence that the activation of oriT for recombination enhancement involves the same strand-specific nick that is required for conjugal DNA transfer. Although it is thought that the role of oriT in recombination enhancement is related to the facilitated entry of RecBCD enzyme into the DNA duplex, we were unable to detect any double-strand breakage at oriT.

Primary prostatic involvement in non-Hodgkin lymphoma

We report 3 cases of primary extranodal lymphoma of the prostate, an unusual extranodal presentation rarely diagnosed antemortem. Symptoms of prostatism associated with an enlarged hard prostate with pyuria and hematuria in younger patients should suggest the diagnosis. Urine cytologic examination should aid in the diagnosis of this condition.

T lymphocyte subsets and antilymphocyte antibodies in lupus nephritis

T lymphocyte subsets were determined in 12 patients with untreated systemic lupus erythematosus (SLE) and in 14 healthy controls. Six out of 8 (75%) patients with lupus nephritis had reduction in the percentage of T helper cells and low helper: suppressor cell ratios compared with controls. None of the 4 patients without nephritis had low ratios. Cold-reactive anti-lymphocyte antibodies cytotoxic to both the helper and the suppressor cells were detected in 7 of the 8 patients who had nephritis. Low T helper: suppressor cell ratio in SLE seems to correlate with the presence of active nephritis.

Thermodynamic proton-ligand and metal-ligand stability constants of some drugs

The thermodynamic proton-ligand (pKa) and metal-ligand stability constants of clioquinol, clofibrate, nitrofurazone, and tetracycline with Cu2+, Zn2+, Mn2+, Mg2+, and Ca2+ have been determined at 35 degrees C in 50% ethanol-water media. An empirical pH correction for mixed-aqueous media has been applied. The metal-ligand stability constants were determined by following the Bjerrum Calvin titration technique as applied by Agrawal to mixed-aqueous solvents. The effect of the basicity of the ligand and the order of stability constants is discussed. The stability constants of the divalent metals follow the order: Cu2+ greater than Zn2+ greater than Mn2+ greater than Mg2+ greater than Ca2+ with all the drugs.

T cell subsets in idiopathic glomerulonephritis

Determination of T lymphocyte subsets using monoclonal antibodies revealed a deficiency of suppressor cells and an elevated helper:suppressor T cell ratio in 7 patients with untreated idiopathic immune complex glomerulonephritis and nephrotic syndrome. Possible pathogenetic mechanisms of immunoregulatory cell imbalance and their implications specifically in reference to idiopathic glomerulonephritis are discussed.

T cell and T cell subset determination in normal peripheral blood: comparison of the indirect immunofluorescence and lymphocytotoxicity techniques

We compared a simple complement-dependent lymphocytotoxicity test with a widely used indirect immunofluorescence procedure to enumerate total T, T helper, and T suppressor lymphocytes in normal blood samples. Results with the two techniques were closely similar.