Intussusception. Issues and controversies related to diagnosis and reduction

Co-operative oxygen binding by the vertebrate haemoglobins arises from an equilibrium between a quaternary structure with low affinity (T), favoured in the absence of ligand, and a high affinity form (R) adopted by the fully ligated protein. While R state haemoglobin has an oxygen affinity close to that of isolated subunits, the affinity of the T state is roughly 300-fold lower. The mechanism by which the T state restrains ligand binding, and the pathway of the quaternary transition, have been largely revealed by detailed crystallographic analyses of a number of haemoglobin molecules in the equilibrium states, as well as intermediate forms of the T state including partially ligated species. The ligation intermediates of the R state, however, have not been as well characterized structurally. We report here the crystal structure of one such intermediate species, namely, horse deoxyhaemoglobin in the R state, at 1.8 A resolution. While ligand binding in the T state may result in unfavourable stereochemistry in and around the haem-ligand complex, the more plastic R structure appears to accommodate equally well both liganded and ligand-free haem. Loss of ligand at the R state haem results in movements of the haem and shifts of the FG corners, which form characteristic intersubunit contacts that distinguish the quaternary states. The shifts are comparable in magnitude to the corresponding movements associated with de-ligation in the T state, although they differ in direction. These and other differences illustrate how the structural changes in the haem pocket are communicated to the subunit interfaces and how the movements that can occur in the R state may be impeded in the T state.     

Spells. Differential diagnosis and management strategies

In summary, when approaching the patient who has had a spell of unknown cause, the most important differentiation to make is between a syncopal episode and a seizure. The history and physical examination will provide the diagnosis in approximately 85% of cases. Once the physician has some idea of which path to pursue, it is important to order the tests in a directed fashion tailored to the patient's presentation. A shotgun approach is neither warranted nor beneficial and is best avoided when possible. Some patients will remain without a diagnosis despite a complete workup, thus it is important for the emergency physician to rule out the life-threatening possibilities and to arrange the appropriate long-term follow-up for the patient with their primary care provider.     

Allergic alveolar diseases. Problems in diagnosis and management

One of the diagnostic possibilities to consider when a patient presents with cough, fever, dyspnea, or pulmonary infiltrates is hypersensitivity pneumonitis. Some of the problems encountered in diagnosis of diffuse lung disease are illustrated in two case reports. In one of the cases, interstitial pneumonitis of insidious onset was attributed to inhalation of thermophilic organisms in moldy silage. In the other, the outstanding pathologic feature was bronchiolitis obliterans, and circumstantial evidence pointed to a home humidifier as the source of the problem.     

Anal neoplasia. Pathogenesis, diagnosis, and management

Prolonged, severe immunodeficiency provides the necessary milieu for the emergence of anogenital neoplasia caused by human papillomaviruses. Anal neoplasia is likely to become a more common manifestation of HIV disease as patients with profound immunodeficiency, who would have succumbed to opportunistic infections earlier in the epidemic, are now surviving for extended periods of time because of increasingly effective antiretroviral, prophylactic, and antimicrobial therapies. The screening and treatment strategies described for use in HIV-infected patients with anal neoplasia are currently being investigated and refined.     

Occupational asthma. Practical points for diagnosis and management

Asthma is a common chronic illness characterized by episodes of reversible airflow obstruction. A cornerstone of asthma management is identifying and avoiding agents that cause bronchospasm. The workplace is an important potential source of respirable exposures that can cause or trigger asthma. Identification of an occupational factor in asthma is important: early diagnosis and removal of the worker from the exposure is associated with improved prognosis; the diagnosis of occupational asthma may lead to compensation for work-related impairment and disability; and the diagnosis of occupational asthma is a Sentinel Health Event with implications for public health and prevention. In this article, we review specific causes of occupational asthma and general settings in which an occupational factor should be suspected and explored as part of the management of the worker with asthma. We also review specific and simple elements of history and pulmonary function testing that can be easily assessed by most health care practitioners and may be sufficient to establish a diagnosis of occupational asthma. Finally, we review the medical-legal implications of occupational asthma.     

Algorithms in the diagnosis and management of exotic diseases. XV. Leprosy

The pharmacokinetic properties of amikacin (BBK8) were similar to those of kanamycin in newborn infants. Peak serum concentrations of both drugs were in the range of 15 to 25 mug/ml with the exception of kanamycin in babies weighing greater than 2,000 g at birth where peak levels were 12.5 to 15 mug/ml. Volumes of distribution, plasma clearances, and serum half-life values were comparable for the two drugs. The clinical and bacteriological responses to amikacin therapy were assessed in 45 neonates with bacterial diseases. A case fatality rate of 26% was observed in infants with septicemia and/or meningitis, whereas no deaths occurred among 22 infants with urinary tract and mucocutaneous infections. Cultures from infected sites were sterile within 72 h of initiating amikacin therapy in 47% of the infants, continued positive for greater than 72 h in 31%, and were not reevaluated during therapy in 22%. The clinical response was judged to be satisfactory in 92% of the surviving infants. The efficacy of amikacin was comparable to that of kanamycin or gentamicin in neonatal bacterial diseases.     

Algorithms in the diagnosis and management of exotic diseases. XVI. Tuberculosis

With few exceptions, the incidence of left colon ischemia following abdominal aortic reconstruction has been reported to be one to 2 percent. All reports of such ischemic events are retrospective analyses of clinically manifest or autopsy. Fifty patients were studied prospectively to determine more accurately the incidence of this complication. Aortic reconstruction was performed in 23 patients for occlusive disease (OD) and in 27 for aneurysm disease (AD). No emergency operations were performed. All patients underwent colonoscopy within 4 days of operation. Three instances of colon ischemia were noted, an incidence of 6 percent (OD 4.3 percent, AD 7.4 percent). Each patient recovered uneventfully. Two patients had diarrhea, but only after colon ischemia was recognized. Arteriographic opacification of the inferior mesenteric artery by the superior mesenteric artery collateral (meandering mesenteric artery) was documented in 35 percent of patients with OD and in 27 percent of patients with AD. Colon ischemia did not develop when this collateral was identified. The inferior mesenteric artery was patent at the aorta in all who developed colon ischema. Although clinically significant colitis following aortic reconstruction is rare, colonoscopy after operation may prove to be valuable for early recognition of ischemic changes before clinical manifestations preclude effective management.     

Genital herpes. Type-specific antibodies for diagnosis and management

The high incidence of unrecognized genital herpes infections and the role of such undiagnosed infections in continuing the spread of genital herpes has been due, in part, to the limited availability of accurate serologic assays for herpes simplex virus types 1 (HSV-1) and 2 (HSV-2). Type-specific serology test kits for HSV diagnosis have been developed and are expected to be widely available in 1998. Clinicians should understand the proper application of these new test and in addition, should be aware that older, inaccurate test will remain on the market for the foreseeable future.     

Esophageal strictures. A radiologic approach to diagnosis and management

Strictures of the esophagus represent persistent luminal narrowing following an inflammatory insult to mural tissues or a manifestation of malignant disease. Barium studies remain the cornerstone of evaluation of patients with a suspected stricture. The diagnostic features of the various causes of strictures are discussed. Balloon dilatation and stent placement, as well as other radiologic interventions, often have an important role in the treatment of patients with advanced disease. This article discusses the indications and general application of these procedures as well as the nature and evaluation of the associated complications.     

Disseminated intravascular coagulation. Objective criteria for diagnosis and management

Current concepts of the cause, pathophysiology, clinical and laboratory diagnosis, and management of fulminant and low-grade DIC have been presented. Considerable attention has been devoted to interrelationships within the hemostasis system. Only by clearly understanding these pathophysiological interrelationships can the clinician and laboratory scientist appreciate the divergent and wide spectrum of often confusing clinical and laboratory findings in patients with DIC. In this discussion, objective clinical and laboratory criteria for a diagnosis of DIC have been delineated, thus eradicating unnecessary confusion and empirical decisions regarding the diagnosis. Many therapeutic decisions to be made are controversial and will remain so until more is published about specific therapeutic modalities and survival patterns. Also, therapy must be highly individualized depending on the nature of DIC, age, cause of DIC, site and severity of hemorrhage or thrombosis, and hemodynamic and other clinical parameters. Also presented are clear criteria for severity of DIC and objective criteria for defining a response to therapy. Also, because it is often difficult for the individual physician to decide when to stop often extensive therapy, objective criteria whereby therapy may be stopped, as continuation is likely fruitless, have been presented as a guideline. Lastly, it should be appreciated that many syndromes that are often organ specific share common pathophysiology with DIC but are typically identified as an independent disease entity, such as hemolytic uremic syndrome, adult shock lung syndrome, eclampsia, and many other isolated organ-specific disorders.     

Complete congenital atrioventricular block. Prenatal diagnosis and perinatal management

OBJECTIVE: To describe our experience in prenatal diagnosis and perinatal management of congenital atrioventricular heart block, as well as pacemaker treatment in the neonate. MATERIAL AND METHODS: A total of 13 fetuses are included. The diagnosis of atrioventricular dissociation was established by Doppler heart rate sample in the right atrium to show the atrial activity while the sample in the Aorta reflected the ventricular heart rate. Gestational age at diagnosis, ventricular heart rates, autoimmune maternal pathology, maternal blood tests for autoantibodies antiRo+, congenital structural heart disease, fetal hydrops, maternal medical treatment, perinatal results and pacemaker neonatal implantation are described. RESULTS: Gestational age at diagnosis ranged between 22 and 32 (mean 27.6) weeks. Ventricular heart rates ranged between 32 to 80 (mean 54) beats/min. AntiRo+ antibodies were detected in 5 mothers, and clinical systemic lupus erythematosus was found in only one. Four had congenital heart disease (2 ventricular inversion and corrected TGA, 1 complete atrio-ventricular canal and 1 tricuspid atresia). Signs of heart failure and hydrops were detected in 9 fetuses. Treatment with beta-metasona and ritodrine was administered to 7 mothers when the ventricular heart rate dropped below 60 beats/min. Intrauterine fetal death occurred in 3 fetuses with structural congenital heart disease and hydrops. Delivery was performed by cesarean section in 8 preterm fetuses (one them a twins), 3 spontaneous deliveries at term and 3 stillbirth. Postnatal pacemaker implantation was carried out in 9 newborns (3 cases with unicameral temporal right ventricle electrode and 6 cases with permanent bicameral electrodes implanted through the subclavian vein and DDD pacemaker). Follow-up of the bicameral pacemaker group was satisfactory. CONCLUSION: Persistent fetal bradycardia is the first sign to diagnose prenatal complete atrioventricular heart block. Echocardiography asses fetal haemodynamic status and may detect signs of fetal deterioration. Hydrops and further drop in the ventricular heart rate warrant urgent cesarean section and pacemaker management of the newborn.     

Issues in the treatment of dual diagnosis clients who have chronic mental illness.

Examines several issues relevant to treating dual diagnosis clients who have coexisting chronic mental illness and substance abuse diagnoses. The development of various theoretical viewpoints on the relationship between substance abuse and mental illness is described along with a critical review of current research efforts. Suggestions are made for professionals to devote more attention to coordinating services and resources within mental health systems, adjusting academic training and professional development, and developing research efforts that will provide practical guidelines for clinicians. Until more definitive research is available, administrators, clinicians, and professional training programs are advised to adopt a broad clinical perspective of work with dual diagnosis clients that incorporates both mental health and substance abuse treatment modalities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Polyneuropathy: diagnosis and management

A polyneuropathy is characterized by a symmetrical distribution of sensory or motor abnormalities, more pronounced distally than proximally and usually more evident in the lower than in the upper limbs. Polyneuropathies may be classified on the basis of (a) clinical picture: acute/subacute/chronic, sensory/motor/autonomous, axonal degeneration/segmental demyelinization, and (b) cause: metabolic disorder, deficiency, infection, auto(dys)immunity, hereditary and toxic/iatrogenic polyneuropathy, with idiopathic polyneuropathy as the remaining group. Damaged nerves may recover as the result of spontaneous remyelinization and axonal regeneration. Treatment is particularly successful in immunomediated neuropathies. Withdrawal is often successful in intoxications and suppletion in deficiencies. Even if no treatment is possible, the diagnosis is important: the patient can be taught to accept his disease and the prognosis can be determined, in connection with possible handicaps.     

Priapism: diagnosis and management

A 32-year-old female patient with a primary adenohypophyseal neoplasm that rapidly progressed to a fatal outcome is presented. The time interval between her admission to the hospital and her death was 3 months. Despite dopamine agonist therapy, local invasion as well as frontal and spinal cord metastases at Th 10-12 region developed, and four surgical resections were performed. The serum prolactin levels were high. Both the primary pituitary tumour and all the metastatic tumours had the same histological findings and immunohistochemical reactions. Each was composed of pleomorphic chromophobic cells with enlarged nuclei. Mitoses and necroses were frequent. Immunostains revealed prolactin in the tumour cells. A literature review revealed that in most of the pituitary carcinomas as in our case hyperprolactinaemia did not respond to medical therapy and the histopathological appearance of the tumour has not correlated with the aggressive behaviour of the tumour. It may therefore be considered that at least some of the cases with metastases in prolactin secreting pituitary carcinomas could be the result of hyperprolactinaemia itself.     

Intrauterine adhesions secondary to elective abortion. Hysteroscopic diagnosis and management

Ten patients who developed Asherman's syndrome following elective first trimester abortion underwent outpatient hysteroscopy under local anesthesia. Six of the 10 patients had hysterosalpingograms prior to surgery. Correlation between the radiographic findings and those at hysteroscopy was poor. Treatment consisted of hysteroscopic lysis of adhesions, placement of an IUD or Foley catheter, and sequential estrogen-progestin administration. Normal menses were resumed in all women. Hysteroscopy was also used for followup in 4 patients. Outpatient hysteroscopy under local anesthesia is safe and is the method of choice for diagnosing, treating, and following patients with Asherman's syndrome.     

Issues in the management of human papillomavirus genital disease

Human papillomavirus (HPV) infects epithelial cells at a variety of anatomic sites. Of the more than 80 types of this virus, approximately one third infect genital tissue. Genital infection can be clinical (warts), subclinical (abnormal Papanicolaou [Pap] smears or lesions visible only with magnification and application of acetic acid) or latent (infection with apparently normal tissue). Recent research has revealed a clear association between genital warts and HPV types 6 and 11, and between cervical cancer and HPV types 16, 18 and others. Women with genital warts who have normal Pap smears do not need colposcopy. All available therapies are suboptimal because HPV is not eradicated by treatment. However, the active disease expression can be eliminated by treatment. The approach to treatment will depend on each patient's personal characteristics and preferences.