Involvement of brown adipose tissue in subcutaneous fat necrosis of the newborn.

BACKGROUND: Subcutaneous fat necrosis (SCFN) of the newborn is a rare condition that manifests within days after birth. The interscapular region, axillae and shoulders are the most commonly affected sites, corresponding to anatomic sites of brown adipose tissue (BAT) in newborns. OBJECTIVE: We postulated a specific involvement of BAT in SCFN and searched for brown adipocytes at affected sites. METHODS: Biopsy specimens were immunostained with antibodies against uncoupling protein 1 (UCP-1) and examined by electron microscopy. We also examined BAT by (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography and computed tomography (PET-CT) scanning. RESULTS: A few cells in biopsy specimens from two patients bound antibodies against UCP-1, and brown adipocytes were detected at several stages of degeneration. PET-CT scans revealed lower uptake of (18)F-FDG at major sites of SCFN. CONCLUSION: SCFN and BAT can be found at the same sites, suggesting a pathophysiological connection.

Root of the small-bowel mesentery: correlative anatomy and CT features of pathologic conditions.

The root of the small-bowel mesentery (SBM) is an important peritoneal fold that is contiguous to other peritoneal ligaments and mesocolons. Several pathologic conditions can occur in the SBM itself, and diseases that spread through the connections from adjacent organs frequently involve it. The root of the SBM is contiguous to the hepatoduodenal ligament around the superior mesenteric vein (SMV) and contiguous to the right side of the transverse mesocolon around the gastrocolic trunk. The inferior mesenteric vein, which is a landmark of the descending mesocolon, runs along the left side of the root of the SBM. Malignant neoplasms can spread to the SBM by means of direct extension, extension along the neural plexus, extension along neighboring ligaments, or extension along lymphatic vessels. Inflammatory conditions such as pancreatitis and perforation of a jejunal diverticulum can also spread to the SBM. Anomalies that can occur in the SBM include rotation anomalies and internal hernia. Vascular lesions of the SBM include thrombosis of the superior mesenteric artery (SMA), acute SMV thrombosis, SMA dissection, arterioportal fistula, and portal venous gas. Other pathologic conditions that can occur in the SBM are edema or congestion, mesenteric tear, mesenteric panniculitis, and tumors or tumorlike lesions.

An immature rat lymphocyte marker CD157: striking differences in the expression between mice and rats.

We have established a novel monoclonal antibody that recognises mouse and rat CD157, and uncovered striking differences in both the level and stage of expression of this antigen in the primary lymphoid organs between these two species. Unlike mouse, the majority of rat thymocytes express CD 157. SHR and WKY rats were the exception, having unusually low levels (similar to those of the mouse) of these cells. However, in both species, a subset of CD3- CD4- CD8- thymocytes exhibited high levels of CD157. Surprisingly, these CD157high cells temporarily upregulated MHC class I molecules in both species. Furthermore, a third of CD157high rat thymocytes were CD45RC+, a marker found on immature thymocytes with regenerative capacity. Examination of the bone marrow lymphoid population shows that the expression of rat CD157 is largely observed at the CD45R+ IgM- pre-B-II cell stage, and unlike mouse, extension of expression into the IgM+ immature B cell stage was marginal. Similar to CD157high immature thymocytes, these immature B cells also expressed high levels of MHC class I. With the exception of the LEC, SHR and WKY rat strains, which have three- to four-fold less CD157+ bone marrow myeloid cells, percentages of these cells are similar between these two species. Thus, marked differences in the level and stage(s) of CD157 expression on lymphoid cells in mouse and rat indicate that CD157 may not, as previously thought, have a direct role in T or B cell differentiation.

Leiomyoma of the parapharyngeal space.

A rare case of leiomyoma of the prestyloid parapharyngeal space is reported together with computed tomographic and magnetic resonance imaging findings. The tumor appeared as a well-circumscribed ovoid mass with some calcifications and lobulations. Because the attenuation, signal intensity, and shape of the mass were not specific and were similar to those of a pleomorhic adenoma, the most common tumor of the prestyloid parapharyngeal space, radiological differentiation of leiomyoma from pleomorphic adenoma of the prestyloid parapharyngeal space was difficult.

Pelvic extension of retroperitoneal fluid: analysis in vivo.

OBJECTIVE: The purposes of this study were to describe the pathway of fluid flow from the retroperitoneal space into the pelvic extraperitoneal space on CT in vivo, to clarify the relation between its occurrence and the site or amount of retroperitoneal fluid, and to delineate the anatomic relation between the retroperitoneal spaces and the pelvic extraperitoneal space. MATERIALS AND METHODS: We reviewed the CT scans of 37 patients with retroperitoneal fluid collections. Patients who had undergone pelvic laparotomy and patients who had either fascial thickening alone or fluid within muscle (such as the psoas muscle or iliac muscle) alone were excluded. RESULTS: Fluid extension into the pelvic extraperitoneal space was seen in six patients (16%). Extension by the infrarenal extraperitoneal space was seen in all six of these patients, but extension by properitoneal fat was seen in only one of the six patients. In patients with large amounts of fluid in the infrarenal extraperitoneal space, we frequently saw extension into the pelvic extraperitoneal space. Extension of pancreatic fluid into the infrarenal extraperitoneal space occurred in only 15% of the 37 patients. However, it occurred in both patients with ruptured abdominal aortic aneurysms. Three pathways from the infrarenal extraperitoneal space into the pelvic extraperitoneal space were seen: extension dorsally medial to the iliac vessels (n = 6), extension dorsally lateral to the iliac vessels (n = 1), and extension medially into the prevesical space (n = 2). Coexistence of two of these three pathways was seen in three patients. CONCLUSION: In vivo, extension of retroperitoneal fluid into the pelvic extraperitoneal space is not rare and occurs more often by the infrarenal extraperitoneal space than by properitoneal fat. Extension of retroperitoneal fluid to the infrarenal extraperitoneal space can be attributed less frequently to sources distant to the pelvic cavity such as pancreatic fluid. Such extension often derives from sources that can produce large amounts of retroperitoneal fluid such as ruptured abdominal aortic aneurysms. Of the three pathways from the infrarenal extraperitoneal space to the pelvic extraperitoneal space, dorsal extension medial to the iliac vessels is the most common, and multiple pathways often coexist.

Appendiceal abscess mimicking infected urachal cyst in a child with intestinal malrotation.

An appendiceal abscess with intestinal malrotation can occur anywhere in the abdomen, not only in the right lower quadrant. We report a case presenting a midline mass of the lower abdomen whose computed tomography (CT) and ultrasonography (US) findings mimicked a urachal abscess. A retrospective review of CT findings led to the correct diagnosis by showing malposition of the ascending colon.

Adenoid cystic carcinoma of the external auditory canal: correlation between histological features and MRI appearances.

A rare case of adenoid cystic carcinoma of the external auditory canal with magnetic resonance imaging appearances is reported. Both T1 weighted and T2 weighted MR images showed the tumour as a hypointense mass, although there was marked contrast enhancement. Microscopic examination of the resected tumour showed a preponderance of solid tumour cell nests. According to previous reports, these pathological and radiological findings indicate a poor prognosis.

TCR V alpha chain expression influences reactivity to the hapten TNP.

We have recently demonstrated a remarkable selection of in vitro cultivated, TNP-specific polyclonal T cell lines for the expression of a TCR beta chain encoded by the V beta 8.2 gene. The goal of the present study was to analyse V alpha usage in V beta 8.2 T cells responsive to TNP, using TNP-specific T cell lines derived from three common strains of mice, as well as from V beta 8.2 transgenic mice. Results indicate that in vitro TNP stimulation of T cells from TNP-immune mice results in significant skewing of V alpha usage among responding V beta 8.2+ T cells, with overexpression observed for V alpha 3.2 and V alpha 8. These results indicate that V alpha expression influences recognition of TNP by T cells, and suggest that the hapten TNP might be recognized like typical peptide antigens by combinatorial TCR alpha and beta contact sites.

Identification of murine T cells reactive with the bacterial superantigen Yersinia pseudotuberculosis-derived mitogen (YPM) and factors involved in YPM-induced toxicity in mice.

We previously reported that Yersinia pseudotuberculosis-derived mitogen (YPM) acts as a superantigen to human T cells. In this study, we assessed the superantigenicity and toxicity of YPM using murine experimental models. YPM activated T cells to produce interleukin-2 in a major histocompatibility complex class II molecule-dependent manner. The T-cell blasts induced by YPM expressed T-cell receptor (TCR) beta-chain variable region (Vbeta)7, Vbeta8.1, Vbeta8.2 and Vbeta8.3. The injection of YPM into mice pre-sensitized with D-galactosamine induced lethal shock. This shock was blocked by the injection of monoclonal antibodies (mAbs) to CD4, TCR Vbeta7 plus Vbeta8, tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma), but not by injection to CD8 or unrelated Vbeta. These results indicate that YPM-induced shock requires the presence of CD4+ T cells bearing TCR Vbeta7 and Vbeta8, and that endogenous TNF-alpha and IFN-gamma mediate the lethal effects.

Percutaneous retrieval of intracardiopulmonary artery metallic needle (Kirschner's wire): a case report.

We report a case of successful percutaneous retrieval of a broken Kirschner's wire that had entered the venous system and the right atrium and later migrated to the left pulmonary artery. The management of a long, rigid, nail-like foreign body within the heart and/or the pulmonary artery is discussed.

[Recent progress in superantigen research].

In 1993 there was substantial progress in superantigen research. The following are the main achievements. (i) The life cycle of an exogenous mouse mammary tumor virus, MMTV (SW), has been clearly eluciated. (ii) X-ray crystallography of toxic shock syndrome toxin 1 has been completed. (iii) The involvement of a superantigen encoded by an endogenous mouse mammary tumor virus, Mtv-51, in the development of a B cell lymphoma has been shown in SJL mice. However, there are many unsolved questions. For example, (i) are there endogenous superantigens in man? (ii) is there any role for superantigens in the development of autoimmunity? (iii) what is the three dimensional structure of superantigens encoded by mouse mammary tumor viruses? In the near future superantigens will be exploited for therapeutic purposes in the area of autoimmunity and cancer.

Family characteristics and offspring growth in various countries. II. Stature of offsprings in various families in Japan and Korea.

The stature of 1219 offspring was examined in 578 families in Japan, and of 672 offspring in 265 families in Republic of Korea. Several traits of parents were investigated, on which using factor analysis four latent factors were extracted. In Japan they consisted of parent's age at child birth (F1), culture level and income (F2), family and apartment size (F3), and genetic factor (F4). The same factors were identified in Korea, but the first two in reverse order. The value of each factor was coded as one when below the median and as 2 when above the median. Using this code, 16 family types were distinguished ranging from 1111 to 2222. The stature of offspring was recalculated in age-independent T-scores. In Japan, family types "maximizing" the stature of offspring were 1122 for boys and 1222 for girls, whereas in Korea 1222 for both sexes, opposite were "minimizing". In the rich populations representing the civilization of the Far East, the factors promoting tall stature of offspring included the low culture-income factor and large family, thus the factors promoting short stature in poor Polish populations belonging to the Western civilization. It is not clear whether this could have been related to the economic status or to different civilization systems.

Family characteristics and offspring growth in various countries. III. Regression of offspring's stature in relation to parent's and family's factors in Japan and Korea.

1219 offspring 2-48 years old were examined in 578 Japanese and in 672 Korean families. To obtain age-independent values, we used 100-point T-scores. A multiple regression analysis, shows that the (tall) stature of Japanese offspring dependent on the genetic factor (tall stature of parents) in about 13%, on (large) family and apartment size in 0.4-1.5%, for sons also on (good) education and income of parents in 0.72%, and for daughters on (young) age of parents at child birth. In Korea, the (tall) stature of offspring was significantly related to the genetic factor (tall parents), which explained 1.8% of the variance for sons and 13% for daughters, and also to the (large) family apartment size, which explained 2.6% of the variance for sons and 0.84% for daughters. These results show in a different light the results obtained from the analysis of family types, and they provide evidence for the importance of the analysis of sets of traits in the form of family types, going beyond the importance of other multivariate techniques.