Amebic liver abscess: MR imaging

Hepatic magnetic resonance (MR) imaging was performed in 12 patients with 13 amebic liver abscesses. While no specific image or intensity pattern was noted, most lesions were round or oval with smooth, well-defined margins; had decreased signal intensity compared with that of liver parenchyma on T1-weighted images and increased signal intensity on T2-weighted images; and had prominent, often multiple rims of variable signal intensity. Signal homogeneity within the abscess was present more often on T1- than on T2-weighted images. Diaphragmatic disruption was seen in two cases on coronal MR images. An amebic empyema was differentiable from sympathetic pleural effusions by its hyperintensity on both T1- and T2-weighted images. In patients who also underwent computed tomography (CT) or ultrasonography (US), no lesion was missed with any modality, and except for shape, no consistent features were found among images obtained with the different modalities. The data suggest that CT, US, and MR imaging are comparably effective in the detection of amebic abscess.     

The changing clinical pattern of Reye's syndrome 1982-1990

OBJECTIVE: To describe trends in the clinical pattern of Reye's syndrome in the British Isles between 1982 and 1990; and to determine the relation between any changes and the June 1986 warnings against the use of aspirin in children. DESIGN: Development, and application to reported cases, of a scoring system designed such that patients showing the typical clinical and pathological features of 'classical' Reye's syndrome scored highly. The relations between 'Reye scores' and a number of explanatory variables were explored using multivariable analysis. SETTING: British Isles. SUBJECTS: 445 cases fulfilling the Reye's syndrome case definition reported to the surveillance scheme between January 1982 and December 1990. MAIN OUTCOME MEASURE: Individual 'Reye score'. RESULTS: Cases with high scores were more likely to have occurred in the 4 1/2 year period before June 1986 compared with the subsequent period (p < 0.006). Numbers of cases in the low and intermediate score categories declined by about 50% after June 1986, whereas those in the high category fell by 79%. High scorers were more likely to have received aspirin (p < 0.0001) and were older than intermediate and low scorers (p < 0.008). No relation was identified between score and season of onset. CONCLUSIONS: The decline in Reye's syndrome after the aspirin warnings cannot be explained entirely, as has been proposed, by improved diagnosis of 'Reye-like' inherited metabolic and other disorders: this would not account for the greater decline of the high scoring subgroup which also contained those cases most likely to resemble 'classical' Reye's syndrome and to have received aspirin. This study provides further evidence for the role of aspirin in a subset of cases meeting the standard diagnostic criteria for Reye's syndrome and supports the need to consider this disorder as a heterogeneous group of conditions including Reye-like inherited metabolic disorders.     

Efficacy of 3,5-dibromo-L-phenylalanine in rat models of stroke,seizures and sensorimotor gating deficit

Background and purpose:

Abnormal glutamatergic activity is implicated in neurologic and neuropsychiatric disorders. Selective glutamate receptor antagonists were highly effective in animal models of stroke and seizures but failed in further clinical development because of serious side effects, including an almost complete set of symptoms of schizophrenia. Therefore, the novel polyvalent glutamatergic agent 3,5-dibromo-L-phenylalanine (3,5-DBr-L-Phe) was studied in rat models of stroke, seizures and sensorimotor gating deficit.

Experimental approach:

3,5-DBr-L-Phe was administered intraperitoneally as three boluses after intracerebral injection of endothelin-1 (ET-1) adjacent to the middle cerebral artery to cause brain injury (a model of stroke). 3,5-DBr-L-Phe was also given as a single bolus prior to pentylenetetrazole (PTZ) injection to induce seizures or prior to the administration of the N-methyl-D-aspartate (NMDA) receptor antagonist dizocilpine (MK-801) to cause disruption of prepulse inhibition (PPI) of startle (sensorimotor gating deficit).

Key results:

Brain damage caused by ET-1 was reduced by 52%, which is comparable with the effects of MK-801 in this model as reported by others. 3,5-DBr-L-Phe significantly reduced seizures induced by PTZ without the significant effects on arterial blood pressure and heart rate normally caused by NMDA antagonists. 3,5-DBr-L-Phe prevented the disruption of PPI measured 3 days after the administration of ET-1. 3,5-DBr-L-Phe also eliminated sensorimotor gating deficit caused by MK-801.

Conclusion and implications:

The pharmacological profile of 3,5-DBr-L-Phe might be beneficial not only for developing a therapy for the neurological and cognitive symptoms of stroke and seizures but also for some neuropsychiatric disorders.     

Interaction of estrogen and histamine during ovum implantation in the rat.

The relationship between estrogen and histamine in the initiation of ovum implantation in the rat was studied. Histamine was found to augment the implantation response to suboptimal doses of estradiol in the ovariectomized pregnant rat maintained with Depo-Provera. The effect of histamine was found to involve both H1- and H2-receptors and to be inhibited by treatment with a combination of mepyramine and metiamide. Treatment with this combination of histamine antagonists during early pregnancy in the intact rat did not modify blastocyst attachment. It was concluded that the effect of histamine on the implantation response to exogenous estradiol was due to increased uterine blood flow and/or estrogen uptake but that such histamine-mediated effects were not essential for blastocyst attachment during normal pregnancy.     

Beware of the flaming hairball--a brief review and warning

Operating room fires are receiving increasing attention in the medical literature and in the general public. The best way to reduce these iatrogenic, sometimes devastating, events is communication and education. The authors present the case of a 14-year-old adolescent girl who had an apparent explosive event during a laparotomy for removal of a large gastric trichobezoar. This event was presumably associated with gas production under increased pressures in the gastrointestinal tract caused by an obstructive and decomposing trichobezoar. This is the first reported association between trichobezoars and potential intraoperative fire and/or injury. It is the recommendation of the authors to avoid the use of electrocautery when initially entering a portion of the gastrointestinal tract thought to contain a bezoar to avoid the potential for surgical fire or concussive tissue damage.     

Acute non-traumatic maternal illnesses in pregnancy: imaging approaches

The imaging methods used to obtain diagnostic information for pregnant patients presenting with acute non-traumatic maternal illnesses have been reviewed. Conditions affecting the gastrointestinal tract, urinary tract, uterus, adnexae, central nervous system and chest have been investigated via a variety of imaging methods, which include ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), intravenous pyelography (IVP), angiography and fluoroscopy. The method of choice, application, and safety to the mother and fetus are considered for investigation of each condition.This revised version was published online in May 2005 with corrections to sequence of authors.     

Pharmacotherapy of affective disorders in children and adolescents

The pharmacotherapeutic management of affective disorders in children and adolescents follows the same general principles as for adults. In addition to the adult principles and guidelines, children present a specific challenge in diagnosis because of the specifics of symptomatology to development. The immaturity of the organism results in less responsivity to biologic therapies because of the poorly established biologic basis of the illness at this stage of life. The metabolic aspects of pharmacotherapy modify dosage and necessitate special attention to the effects of pharmacotherapeutic agents on physical and emotional development.     

Small cell neuroendocrine carcinoma of the vagina.

A 65-year-old woman with a history of recurrent vaginal intraepithelial neoplasia was found to have small cell carcinoma (SCC). Exfoliative cytology was instrumental in the discovery of each episode of vaginal neoplasia. Thorough examination of the patient established the tumor as being primary to the vagina, and immunohistochemistry confirmed it to be a neuroendocrine SCC. Eleven patients with neuroendocrine SCC of the vagina have been reported previously. Morphologic characteristics and histogenesis are discussed within the context of the embryology and natural history of extrapulmonary-genital SCC. They have been classified in the amine precursor uptake and decarboxylation family of neoplasms. Originally, a neuroectodermal origin was proposed, but derivation now is thought to be from multipotential epithelial stem cells of the genital tract. Neuroendocrine SCC tends to be an aggressive neoplasm with a propensity for early spread. Long-term survival for patients with vaginal SCC has not been documented. Therapeutic decisions regarding SCC from this site have been based on information gained from the treatment of these tumors elsewhere. Combined modality therapy using initial surgery and adjuvant treatment, including systemic chemotherapy and local exposure to radiation, has produced an apparent complete response in our patient.