Mr imaging of hepatic nodular regenerative hyperplasia

Nodular regenerative hyperplasia (NRH), a rare condition that is commonly associated with noncirrhotic portal hypertension, is not well described in the MR literature. Three patients at two institutions were identified who had both abdominal MR imaging and pathologic evidence of NRH. All examinations were performed at 1.5 T and included axial T1- and T2-weighted spin-echo (SE) images. The MR studies were reviewed by two radiologists in consensus. Two patients had multiple liver lesions that had high signal components on T1-weighted images and were predominantly isointense with liver on the T2-weighted images. One patient had no focal lesions identified. NRH, when visualized on MR images, appears as multifocal masses with shortened Tl and T2 similar to liver. NRH should be considered in the differential diagnosis of hepatocellular tumors, especially in patients with a predisposing condition.     

Comparison of Two Formulations of Nifedipine During 24-Hour Ambulatory Blood Pressure Monitoring

Study Objective . To determine if one commercial extended-release formulation of nifedipine (Adalat CC) is as effective as another (Procardia XL) in controlling blood pressure over 24 hours. Design . Open-label, randomized, crossover study. Setting . University-affiliated family medicine clinic. Patients . Fifteen patients with stage 1–4 primary hypertension. Interventions . Procardia XL or Adalat CC once/day was titrated to achieve blood pressure control. The effective dose was continued for 4 weeks, washed out for 1 week, and reinstituted with other study drug. Measurements and Main Results . Twenty-four-hour ambulatory blood pressure was recorded the conclusion of each treatment phase. Treatment phases were compared for mean 24-hour blood pressure, mean daytime (6:00 a.m.–10:00 p.m.) and mean nighttime blood pressure, and mean blood pressure load (percentage of blood pressure measurements < 140/90 mm Hg daytime and > 120/80 mm Hg nighttime). Thirteen patients completed the study. No statistically significant difference was seen in mean 24-hour blood pressure (138/86 mm Hg for Procardia XL vs 137/85 mm Hg for Adalat CC), daytime or nighttime blood pressure, or blood pressure load. Two patients experienced clinically significant adverse effects while taking Adalat CC. Conclusions . In these patients with primary hypertension, Adalat CC was as effective as Procardia XL at controlling blood pressure for 24 hours. Blood pressure, heart rate, and adverse effects should be monitored 2–4 weeks after any exchange of Adalat CC for Procardia XL.     

A scanning electron microscopic and photon absorptiometric study of the development, prolongation, and pattern of recovery from lactation-induced osteopenia in rats

Measurements by scanning electron microscopy (SEM) of femoral hemisections confirmed and amplified results by single-photon absorptiometry that had shown a marked increase in lactation osteopenia in rats fed a low-calcium diet (LCD, 0.04% Ca) as compared with a medium-(adequate) calcium diet (ACD, 0.4% Ca). SEM of bones from rats at the end of lactation on either diet showed a large loss of trabecular bone, increased porosity of endosteal surfaces, and cortical thinning. These changes were much more striking in LCD rats than in ACD rats. Backscattered electron imaging of cross sections of the femora revealed marked cortical thinning at midshaft after lactation, especially in rats on the LCD; this method also showed a marked increase in newly formed, less dense diaphyseal bone on the endosteal surface when dietary calcium had been made available to the LCD rats after lactation ceased. Unlike the rats fed the ACD after lactation, the rats continued on the LCD for the first 3 weeks postlactation failed to recover bone mineral, even though there was a marked decrease in resorbing surfaces of the femora as revealed by morphologic examination. When the diet was changed from the LCD to the ACD for the second 3 weeks postlactation (week 4-6), the bone mineral increased substantially. Overall, these results demonstrate the marked loss of bone during lactation, especially severe in rats fed a low-calcium diet, and the rapid postlactational recovery of bone when adequate dietary calcium was made available, even if the recovery had been delayed for the first 3 weeks by feeding a diet very low in calcium.     

Disarticulation resections of the mandible: a prospective review of 16 cases.

PURPOSE: This article provides a review of the disarticulation resection of the mandible for various benign and malignant tumors and non-neoplastic processes. In so doing, the author proposes a classification to describe extension of pathology into the condylar region, thereby requiring its sacrifice. Recommendations are also proposed for preservation versus sacrifice of the meniscus when performing a disarticulation resection of the mandible. Finally, complications are evaluated in this type of mandibular resection. PATIENTS AND METHODS: This review is based on the author's accumulated clinical data obtained from performing disarticulation resections on 16 patients who presented with 10 different pathologic diagnoses. Disarticulation resections are performed for 3 different patterns of extension of pathologic processes into the condylar region, designated as type I, type II, and type III by the author. These designations reflect the radiographic involvement of the condyle or subcondylar region of the mandible by the pathologic entity. The designations of type II and type III extensions are diagnosis dependent, whereas type I extension is independent of diagnosis. RESULTS: Five patients in this series presented with type I condylar extension, 2 patients presented with type II condylar extension, and 9 patients presented with type III condylar extension. The meniscus required sacrifice in 3 of the 16 patients. Complications occurred in 3 of 16 patients and included 1 dislocation of the plate into the middle cranial fossa, 1 dislocation of the plate inferiorly and posteriorly to the mastoid process, and 1 cutaneous exposure of the plate. CONCLUSIONS: Disarticulation resections are rarely required variants of segmental resection of the mandible, and they are required by a variety of pathologic processes of the jaws and contiguous structures. The placement of a reconstruction bone plate with an affixed condylar prosthesis is well tolerated by patients and is associated with few complications. These reconstruction bone plates favorably support facial form, symmetry, and occlusion such that many patients delay their definitive bony reconstruction. Because these condyles are temporary prostheses, the surgeon should consider their removal with bony reconstruction of the disarticulation defect as soon as possible after the ablative surgery.     

How often can the clinical diagnosis of exanthema subitum be confirmed with the HHV-6 serology test

Three years ago a newly recognized human herpes virus (HHV-6) was identified to be the causative agent for exanthem subitum (roseola infantum). So far this diagnosis was suggested chiefly by excluding other infections and the presence of a typical course of the disease. To find out how often the clinical diagnosis can be confirmed serologically, we asked five pediatricians in private practice as well as residents of the out-patient and infant departments of our hospital to obtain paired heparinized blood samples of any child suspicious for exanthem subitum. 36 children with clinically suspected exanthem subitum and a mean age of 14.2 (5-71) months were included in this prospective study. Indirect immunofluorescence was used to detect IgG and IgM antibodies to HHV-6. In 22 children (61%) the clinical diagnosis was confirmed serologically. IgM antibody was found in only 16 of these 22 children. In 8 patients the results were ambiguous. Three had in the same time a doubtful seroconversion to other viruses of the herpes group (HSV twice; EBV once), in four children there was an insufficient rise in IgG antibodies without presence of an IgM response, and once we found a very high HHV-6 specific antibody titre (greater than 1:80) in both serum samples. In 6 children neither a seroconversion nor a rise in HHV-6 antibody titre were found. Retrospectively, only three of these children had a clinical course really typical for exanthem subitum. We conclude that in most cases the clinical diagnosis of exanthem subitum will be confirmed by serological examination.(ABSTRACT TRUNCATED AT 250 WORDS)