bluuebunny/crossref_metadata_2025_split huggingface dataset:
BACK TO BASICS
Authors: Rubenstein Jeffrey S. 
Published: December 2021

The last 20 years have seen an explosion in our knowledge of the autonomic nervous system and our ability to manipulate its parasympathetic and sympathetic portions pharmacologically to achieve therapeutic goals. This article will briefly review the structure and function of the autonomic nervous system, with particular focus on the sympathetic branch. Included in the review is a discussion of the major receptors of the sympathetic system, concentrating on their intracellular mechanism of action, their effects on major target organ systems, and some commonly used pharmacologic agents that influence these organ systems through their actions on sympathetic receptors.
Structure and Function of the System
The autonomic (or involuntary) nervous system innervates the heart, visceral organs, blood vessels, smooth muscles, and glands. It can be divided functionally into the parasympathetic and sympathetic systems, which have opposing functions. All autonomic nerve pathways consist of two nerves in sequence. Presynaptic nerves begin in the central nervous system and transmit impulses to the postsynaptic nerves. Postsynaptic nerves then carry impulses to the effector organ.
Actions of the parasympathetic nervous system include bradycardia, vasodilation in skeletal muscle and skin, contraction of bronchial smooth muscle, increased gastrointestinal motility, pupillary miosis, and contraction of the bladder detrusor coupled with relaxation of the bladder trigone (necessary for spontaneous voiding).
Hearing Disorders
Authors: Rapin Isabelle 
Published: December 2021

Definition
Hearing is the usual channel for acquisition of this most important of human attributes, language. Language enables humans to communicate at a distance and across time and has played a decisive role in the development of society and its many cultures. Language is the major channel through which children learn about what is not immediately evident, and it plays a central role in thinking and cognition. Because speech is the chief vehicle for communication in all families (except those in which the parents are deaf), deafness is a profound handicap whose effects greatly transcend the inability to speak. Responsibility for detecting hearing loss in infancy rests on the primary physician, inasmuch as early diagnosis and appropriate habilitation will prevent the most serious consequences of infantile hearing loss: growing up without language.
Two primary types of hearing loss are attributable to disease of the ear: conductive hearing loss, a deficiency in the transduction of energy in the form of sound waves in air to hydraulic waves in the inner ear; and sensorineural hearing loss, inadequate transduction of these waves to neural activity. Other disorders of hearing include cortical hearing impairment and perceptual disorders. Although much is said about perceptual disorders by educators, such disorders probably play a minor role in the genesis of learning disabilities and will not be addressed in this review, which focuses on severe-to-profound hearing losses.
Disordered Control of Breathing in Infants and Children
Authors: Carroll John L. , Marcus Carole L. , Loughlin Gerald M. 
Published: December 2021

Introduction
Breathing must be tightly regulated so that the amount of oxygen inhaled and carbon dioxide exhaled matches precisely the metabolic needs of the body. Acute malfunction of breathing control mechanisms, even for a few seconds, may lead rapidly to serious physiologic derangements, with death as the final outcome if the system fails to recover. Chronic malfunction of breathing control mechanisms may lead to chronically abnormal blood gases (eg, hypoxemia), with such consequent complications as developmental delay or cor pulmonale. Because the upper airway is shared for breathing, eating, drinking, and talking, control of breathing also encompasses coordination of these actions in such a way that all are carried out effectively. The upper airway also must be actively held open during sleep or it will collapse during the inspiratory phase of breathing. Tone and activity of the muscles that maintain upper airway patency are controlled, in part, by the respiratory control systems. Malfunction of upper airway control mechanisms may play a role in obstructive sleep apnea. Thus, respiratory control not only refers to the control of gas exchange, but encompasses breathing pattern, apnea, respiratory protective reflexes, and upper airway control—specifically, maintenance of upper airway patency.
This review will cover infant apnea and home cardiorespiratory monitoring, apparent life-threatening events (ALTEs) and home monitoring, obstructive sleep apnea syndrome (OSAS) in children, central hypoventilation syndromes, and hyperventilation syndromes.
Medical Record Documentation of Chronic Abdominal Pain
Authors: Shah H. 
Published: December 2021

Name: Martha McCue1
Date of birth: June 24, 19842
Drug allergies: None known3
Immunizations: Complete4
Thursday, December 3, 1992
CHIEF COMPLAINT: "She's been having stomach aches since summer."
PRESENT ILLNESS: (without prospective diary) Stomach hurting off and on since end of summer. May have started on vacation. Says stomach hurts "lots of days." Many times too uncomfortable to go to school or mother has to get her. School nurse worried there is something wrong. Pain is usually "in middle." No obvious relation to meals; "can happen anytime." Not sure if it wakes her up, "but sometimes I have bad dreams." Pain lasts "a long time." Appetite normal for her; picky eater. No obvious relation to specific foods. Thinks bowel movements are normal; can't remember how often. No discomfort urinating. Has not had temperature taken. Remembers vomiting once. Mother thinks one bout was related to taking antibiotic.
PRESENT ILLNESS: (with prospective diary) Father had vomiting and diarrhea mid-August on vacation; better in 4 days. Martha caught it and had pronounced cramps. Not a week without abdominal pain since then. Several bouts a week. Diary shows pronounced pain on Sunday evenings, Monday mornings, Tuesday mornings, causing school absence 3 days. Milder discomfort on other days. No pain over Thanksgiving vacation until Sunday night.
Fluid and Electrolytes: Clinical Aspects
Authors: Hellerstein Stanley 
Published: December 2021

Dr Daniel C. Darrow, a clinician and one of the investigators whose contributions helped lay the foundation of modern fluid therapy, made the following observation in his book, A Guide to Learning Fluid Therapy: "Fluid therapy inevitably is carried out by rules which achieve results without requiring continual resort to complicated scientific reasoning. The chief difficulty is that no simple rules based on body weight or surface area meet the varying physiological requirements by infants, children, and adults. Nevertheless, by recognizing that body size has two dimensions, the same general rules apply at all ages to patients of different weights."
The dimensions of body size pertinent to fluid therapy are caloric production and weight. The usual ongoing fluid expenditures—maintenance fluids—are related to energy production, while restoration of normal body composition in patients with water and electrolyte deficits on excesses are related to changes in body weight. It should be added that when fluids for a patient are prescribed based on "convenient rules," the physician must be aware of the assumptions that renal function is not significantly impaired and that the homeostatic mechanisms for conservation and excretion of water and solute are intact. If this is not the case, the provision of water and electrolytes must be based on assessment of ongoing fluid expenditures.
Vulvovaginitis in the Child and Adolescent
Authors: Vandeven Andrea M. , Emans S. Jean 
Published: December 2021

Adolescents and children experiencing vaginal discharge and irritation present frequently in a pediatric practice. Although there are distinct differences in the epidemiology of vulvovaginitis in the child and adolescent, a standard approach to evaluation can be followed in both the prepubertal and postpubertal child.
Definitions
In practice, the terms vulvitis, vaginitis, and vulvovaginitis often are used interchangeably by physicians in diagnosing inflammatory conditions of the lower female genital tract. Although the infection or irritation may have been localized at onset, by the time of presentation it may have become generalized. Vulvitis may occur alone or be accompanied by a secondary vaginitis. Conversely, a child may acquire a primary vaginal infection, and the discharge may cause maceration of the vulva and a secondary vulvitis. Presenting symptoms of vulvovaginitis can include genital irritation, pain and inflammation, vaginal discharge, and dysuria. Thus, a variety of presenting complaints are due to vulvovaginitis.
Epidemiology and Pathogenesis
Familiarity with the anatomy and normal developmental changes of the female genital tract is essential to understanding the etiology of and pre-disposing factors for vulvovaginitis.
During the newborn period, the vagina is well-estrogenized from maternal hormones. The desquamation of the estrogen-induced hypertrophic vaginal epithelium, together with mucus from the stimulated cervix, produces the physiologic white discharge seen in the neonate.
Hypertension in Childhood and Adolescence
Authors: Jung Flavia F. , Ingelfinger Julie R. 
Published: December 2021

Hypertension
The prevalence of hypertension in childhood is low (1% to 3%), and the majority of affected children have only mild elevations of blood pressure (BP), which are thought to be early manifestations of primary hypertension. A minority of hypertensive children (about 10%) have more marked elevations in BP, and these individuals often have secondary hypertension. Of those children who have a definable cause for their hypertension, 80% to 90% have renal or renovascular disease as an underlying cause. Therefore, the strategy for evaluating a child for secondary causes of hypertension generally is aimed at finding renal or renovascular disease as well as less common causes. The major conditions associated with sustained hypertension are listed in Table 1; causes of acute hypertension are listed in Table 2.
Measuring Blood Pressure
A number of children who do not actually have hypertension exhibit "high" BP upon the initial examination. Many of these children are large for their chronologic age, and usually their BP has been measured with an inappropriately small cuff. Falsely elevated pressures may be obtained with a cuff that is too small, but falsely positive low BP is rare, even if the cuff is too large. When used on an upper extremity, the BP cuff should cover at least two thirds of the upper arm; the internal bladder should encircle at least 80% of the arm circumference to avoid inaccurately high readings.
INDEX OF SUSPICION
Authors: Berera Geeta , Magill Frank B. , Oblender Melanie 
Published: December 2021

This section of Pediatrics in Review reminds clinicians of those conditions that can present in a misleading fashion and require suspicion for early diagnosis. Emphasis has been placed on conditions in which early diagnosis is important and that the general pediatrician might be expected to encounter, at least once in a while. The reader is encouraged to write possible diagnoses for each case before turning to the discussion, which is on the following page.
We invite readers to contribute case presentations and discussions.
Case 1 Presentation
The parents of a 6-year-old boy would like your opinion regarding a tonsillectomy and adenoidectomy for their son. His speech development has been delayed, and even now, despite 2 years of therapy, he is difficult to understand. The child had experienced recurrent ear infections for which pressure equalization tubes were placed 4 years ago. Physical examination reveals bilateral serous otitis media and a bifid uvula. The tonsils appear normal for his age. His speech has a hypernasal quality. An audiologic evaluation reveals bilateral conductive hearing loss. You see a pattern that suggests an underlying condition with important therapeutic implications.
Case 2 Presentation
A 6-week-old infant is brought to the emergency room because of bleeding from the umbilicus for 8 hours.
Consultation with the Specialist
Authors: Yamauchi Terry 
Published: December 2021

Introduction
The enterococci, normal inhabitants of the human and animal bowel flora, were considered for years to be nonvirulent microorganisms. Over the past decade, however, the role of enterococci in human disease has taken on new importance. Serious diseases, such as bacteremia, which is associated with significant mortality, and endocarditis, are prime examples of human enterococcal infections. More recently, the wide-spread use of antimicrobial agents has led to the emergence of multiresistant microorganisms, previously considered to be nonpathogenic, as significant agents in human diseases.
Morphologically, enterococci are gram-positive cocci that grow in chains and resemble streptococci. Previously, enterococci were placed in the Lancefield Group D streptococci genus; currently, they are in a new bacterial genus classification Enterococcus (Table).
Clinical Diseases
Enterococci may cause serious infections in the hospitalized patient and have been reported as the third leading cause of nosocomial infections in the United States. The recovery of enterococci from the urinary tract, surgical wounds, and the blood documents the importance of these bacteria in hospital-acquired infections.
[See table in the PDF file]
The urinary tract is the most common site infected by enterococci. Surgical instrumentation, intervention, and catheterization are invasive procedures that place the patient at risk for enterococcal infection.
The Acute Management of Paroxysmal Supraventricular Tachycardia in Children
Authors: Erickson Lars C. , Cocalis Mark W. 
Published: December 2021

Supraventricular tachycardia (SVT) in children is a common disturbance of cardiac rhythm that is usually managed without difficulty by using a methodical approach. Technically, the term SVT refers to any rapid rhythm originating in or involving the atria or atrioventricular (AV) node. The most common type of SVT treated in the pediatric clinic is a reentrant rhythm involving the AV node or a bypass tract (paroxysmal SVT [PSVT]). This type of SVT is characterized by sudden onset and cessation, very little beat-to-beat variability, and rates usually well beyond 220 beats/minute. Reentrant rhythms are susceptible to vagal maneuvers, pharmacologic intervention, and electrical cardioversion. Other types of SVT include atrial flutter (rare in children) and automatic tachycardias, which tend to vary in rate over time and start and stop more gradually. It is important to distinguish automatic tachycardias from PSVT because they do not resolve with vagal maneuvers or electrical cardioversion and because they are notoriously difficult to manage with medications. The automatic tachycardia most frequently confused with PSVT is sinus tachycardia, which usually requires no treatment.
The first step in evaluation is to check the hemodynamic status. A small proportion of children who have PSVT may present with shock. If the child is hypotensive or has poor capillary refill, one must start immediate measures to restore effective perfusion, including securing reliable intravenous (IV) access and supine positioning.
Giardiasis
Authors: Seidel James 
Published: December 2021

Giardiasis is caused by infection with the protozoan parasite Giardia lamblia, also called Giardia intestinalis in Europe.
Epidemiology
Giardia infections are ubiquitous, and outbreaks occur in developed and underdeveloped nations throughout the world. Infection results from ingestion of cysts, usually contained in water or food, on hands, or on fomites contaminated with feces. The parasite is found in about 4% of stool specimens submitted to laboratories in the United States and is the most common parasite isolated. The exact prevalence of the infection in the United States is not known because it is not reportable in all states and may be difficult to isolate in the laboratory. Epidemic giardiasis in day care centers was first reported in 1977, with infection rates varying from 0 to 25%. Most children have symptoms. Chronic passage of cysts by some preschool children in day care facilities is found 5 to 6 months after the initial diagnosis, either because of continued transmission or chronic infection. Prevalence rates decline when children are toilet-trained. Sexual transmission may occur in heterosexual or homosexual contacts.
Campers and hikers are at risk because of vertical transmission from animals, and waterborne outbreaks in national parks have been reported. In addition, many outbreaks have been attributed to municipal water supplies that have not been treated with flocculation or filtration.
Gastroenteritis
Authors: Northrup Robert S. , Flanigan Timothy P. 
Published: December 2021

Diarrheal disease is so common and so often short-lived and apparently benign that neither physicians nor parents may give it the attention it deserves. Unfortunately, this lack of concern plays an important role in the high mortality rate from diarrhea among children in developing countries. It also contributes to the high numbers and costs of hospitalizations for diarrhea in the United States.
This review focuses on acute infectious diarrhea and on persistent diarrhea. These two conditions begin similarly, but persistent diarrhea by definition persists for longer than 14 days. It emphasizes appropriate management, particularly oral rehydration therapy (ORT) and current recommendations regarding feeding during diarrhea, and addresses new information about pathogens that cause both acute and persistent diarrhea. Although ulcerative colitis, Crohn disease, and other causes of chronic diarrhea must be considered in the differential diagnosis of acute or persistent diarrhea, a thorough discussion of chronic diarrhea is beyond the scope of this article. Information from developing countries as well as from the US and other developed countries is included.
Epidemiology
Gastroenteritis, both acute and persistent, may occur as often as 15 times per year in a child, although rates of 3 to 5 episodes annually are seen more commonly in most developing countries.
Myelodysplasia in Childhood and Adolescence
Authors: Blum Robert Wm. , Pfaffinger Kathleen 
Published: December 2021

The Nature of the Condition
Myelomeningocele—also commonly referred to as meningomyelocele—is a defect of neural tube formation that is akin embryologically to anencephalus. The larger category, spina bifida, includes the benign condition of spina bifida occulta; myelodysplasia is inclusive of all neural tube anomalies. Myelomeningocele is the most common major congenital anomaly in the United States, having an incidence, until recently, of 4 per 1000 births (see Epidemiology).
Approximately 80% of all children born having myelomeningocele have associated hydrocephalus. Likewise, nearly all of these children are born having Arnold-Chiari (or Chiari II) malformation of the midbrain and upper spinal cord, which is associated with displacement of the inferior cerebellar vermis, caudal fourth ventricle, and medulla oblongata into the spinal canal. The Arnold-Chiari malformation may cause its own symptom complex, including lower cranial nerve dysfunction, sensory loss, and spasticity.
The extent of neurologic, urologic, and orthopedic involvement depends primarily on the level of the lesion (Table 1). Additionally, the work of Luthy et al strongly suggests that if the condition is diagnosed prenatally, infants delivered via cesarean section have significantly less paralysis at 2 years of age than do those who have comparable lesions and who are delivered vaginally.
Additional complicating factors and associated findings of myelomeningocele may include:
Acne Vulgaris: Pathogenesis and Management
Authors: Hurwitz Sidney 
Published: December 2021

Acne, a problem well known to pediatricians and general practitioners alike, never should be dismissed as being of no consequence, with the reassurance that the patient will outgrow it. The psychological scars of individuals affected with severe forms of this disorder often are far deeper and more disastrous than the blemishes appearing on the cutaneous surface. For years the treatment of acne was hindered by: 1) mythical concepts of etiology, 2) a lack of concern for the physical and emotional trauma of those afflicted with severe forms of this disorder, and 3) the perpetuation of ineffective therapeutic regimens based on misconceptions and misinformation. Although the basic cause of acne remains unknown, considerable data concerning its pathogenesis and treatment accumulated in recent years now allow a rational and therapeutically successful approach to its management. Therapy must be individualized, however, with variations and modifications appropriate to the fluctuating severity of the disorder. Today, this goal can be achieved easily by proper selection of available medications, coupled with the cooperation of the patient and the knowledge, continued interest, and enthusiasm of the physician and his or her staff.
Etiology
Although generally considered a disorder of adolescence, acne vulgaris, a chronic inflammatory process at the pilosebaceous follicles, usually begins 1 or 2 years prior to the onset of puberty as a result of androgenic stimulation of the sebaceous glands.
The Cephalosporin Antibiotics
Authors: Darville Toni , Yamauchi Terry 
Published: December 2021

Introduction
The first cephalosporin released for clinical use was cephalothin in 1964. Since that time, more than 20 cephalosporin antibiotics have been introduced. These are the most commonly prescribed antibiotics in the United States and account for the largest share of hospital expenditures. To determine which agent to use for an infection in a particular patient involves weighing competing claims of improved antibacterial spectrum, side effects, pharmacokinetics, and cost. This review will address these issues, as well as the basic mechanisms of action of the cephalosporins and their mechanisms of bacterial resistance. In addition, instances in which cephalosporins serve as appropriate alternatives or in which they offer distinct advantages over previously available antimicrobial agents will be described.
Chemistry and Mechanism of Action
Cephalosporins resemble penicillins (Fig.1) in that they have a β-lactam structure, but the five-member thiazolidine ring characteristic of the penicillins is replaced by a six-member dihydrothiazine ring (Fig. 2). The dihydrothiazine ring of the cephalosporins provides the molecule with the ability to resist bacterial enzymes; the antibacterial activity emanates from the β-lactam ring shared by penicillins and cephalosporins. Modifications at position 7 of the cephalosporin nucleus generally affect the antibacterial spectrum, and substitutions at position 3 of the dihydrothiazine ring alter the pharmacokinetics and metabolic parameters of the drug.