S100A6 expression in cutaneous smooth muscle neoplasms

The S100A6 protein is expressed in a variety of tissues and distinct staining patterns in S100A6 immunohistochemistry may be useful in the differential diagnosis of difficult lesions. We evaluated the staining pattern of the S100A6 antibody in 22 cases each of pilar leiomyoma (LM), angioleiomyoma (ALM), and cutaneous leiomyosarcoma (LMS). S100A6 labeled both the nucleus and cytoplasm of myocytes in positive cases. About 64% of LM and 86% ALM had positive staining to the S100A6 antibody but predominantly in a weak staining pattern. In contrast, 95% of the LMS exhibited moderate to strong staining with the S100A6 antibody. The difference in the frequency of positive cases was statistically significant in the LM vs LMS comparison (p = 0.025), but we found intensity of staining to be of greatest practical utility. Analysis between the groups taking in to consideration differences in intensity of staining using the nonparametric rank sum (Mann–Whitney U test) demonstrated that there was a statistically significant difference between LM and LMS and between ALM and LMS. Weak or absent S100A6 staining supports a diagnosis of LM, whereas strong positive staining supports a diagnosis of LMS.     

Insulin-Dependent Diabetes Mellitus in Non-DR3/Non-DR4 Subjects

ABSTRACT: Five to 20% insulin-dependent diabetes mellitus (IDDM) patients do not bear the classical HLA class II DR3 or DR4 susceptibility haplotypes. We have studied the clinical characteristics, anti-islet cell antibodies (Ab) and HLA class II genotypes in 72 non-DR3/non-DR4 Caucasian patients, mainly adults, presenting with clinically typical IDDM. The DRB1*08-DQB1*0402-DQA1*0401 haplotype frequency was increased in the patients compared to 272 non-DR3/non-DR4 controls (OR = 5.9, Pc < 0.005). This association was even stronger in the Ab-positive patients (DRB1*08: OR = 7.2, Pc < 0.005; DQB1*0402: OR = 9.2, Pc < 0.005; DQA1*0401: OR = 9, Pc < 0.02). In those subjects the DRB1*15 allele was less frequent than in controls (OR = 0.1, Pc = 0.05). By contrast, IDDM patients with no Ab showed no particular association with HLA class II allele although they had clinical and metabolic characteristics similar to that of Ab-positive subjects. The genetic basis for IDDM predisposition in the Ab-positive subgroup remains elusive since the DRB1*08-DQB1*0402 haplotype encodes an Asp57-positive DQβ chain. However, all DR8 patients had a non-Asp57 encoding DQB1 allele on the second haplotype. Thus, trans-complementation leading to peculiar predisposing DQβ heterodimers may occur. Alternatively, a direct role of the DRB1*08 allele cannot be excluded. These results show that autoimmune type 1 diabetes occurs in non-DR3/non-DR4 subjects, mainly adults. They further support that IDDM, when defined on a clinical basis, encompass different pathogenetic entities.     

Evaluation of chromogenic medium Uriselect4 in urine culture

We evaluated the performance and the cost of chromogenic medium Uriselect4 agar with regard to the standard medium for the detection and identification of urinary tract pathogens. A total of 503 clinical urine specimens containing leucocytes greater or equal to 104/mL were analysed prospectively, in parallel by two different persons on blood agar (GS) and Uriselect4 according to the manufacturers' instructions. Of the 503 urine specimens tested, 210 gave a positive culture on Uriselect4 versus 181 on GS. The majority of bacterial species grew on both media; enterobacteria grew on Uriselect4 better than GS. The identification of Escherichia coli (E. coli), Proteus mirabilis (P. mirabilis), KES group and Enterococcus faecalis (E. faecalis) did not require the use of galleries Api and has a gain of 24 h. Positive pure cultures on Uriselect4 corresponding to negative cultures of GS were noted in 17 ases. Conversely, in seven cases a positive pure culture on GS was noted while the corresponding Uriselect4 cultures were negative. The cost of identification on GS (including the cost of galleries Api), was about two times higher than Uriselect4. Uriselect4 medium isolates the most frequent urinary tract pathogens and identify them so almost immediately, with a lower cost.     

Two binding sites for [3H]PBR28 in human brain: implications for TSPO PET imaging of neuroinflammation

[¹¹C]PBR28, a radioligand targeting the translocator protein (TSPO), does not produce a specific binding signal in approximately 14% of healthy volunteers. This phenomenon has not been reported for [¹¹C]PK11195, another TSPO radioligand. We measured the specific binding signals with [³H]PK11195 and [³H]PBR28 in brain tissue from 22 donors. Overall, 23% of the samples did not generate a visually detectable specific autoradiographic signal with [³H]PBR28, although all samples showed [³H]PK11195 binding. There was a marked reduction in the affinity of [³H]PBR28 for TSPO in samples with no visible [³H]PBR28 autoradiographic signal (K_i=188±15.6 nmol/L), relative to those showing normal signal (K_i=3.4±0.5 nmol/L, P<0.001). Of this latter group, [³H]PBR28 bound with a two-site fit in 40% of cases, with affinities (K_i) of 4.0±2.4 nmol/L (high-affinity site) and 313±77 nmol/L (low-affinity site). There was no difference in K_d or B_max for [³H]PK11195 in samples showing no [³H]PBR28 autoradiographic signal relative to those showing normal [³H]PBR28 autoradiographic signal. [³H]PK11195 bound with a single site for all samples. The existence of three different binding patterns with PBR28 (high-affinity binding (46%), low-affinity binding (23%), and two-site binding (31%)) suggests that a reduction in [¹¹C]PBR28 binding may not be interpreted simply as a reduction in TSPO density. The functional significance of differences in binding characteristics warrants further investigation.     

Case report: an unusual case of adrenal neuroblastoma in pregnancy

Neuroblastomas are the fourth most common malignancy of childhood and account for most adrenal tumors in children. However, they are rarely reported in adults. We present herein an extremely rare case of adrenal neuroblastoma occurring in a 25-year-old woman during her first trimester of pregnancy. She had a spontaneous abortion secondary to chorioamnionitis and she was operated on for an "incidentaloma." Her tumor was curatively resected. She presented with right lower quadrant abdominal pain 26 months after her operation and there was evidence of local tumor recurrence without metastasis. Adult adrenal neuroblastoma is an uncommon malignancy and, to our knowledge, there was no case of this tumor occurring in pregnancy ever described in the English literature. The case presentation is followed by a general discussion with an emphasis on the diagnosis, treatment, and follow-up of neuroblastoma and its association with pregnancy.     

Arterial switch in simple and complex transposition of the great arteries

Arterial switch for repair of transposition of the great arteries was performed on 53 patients since October 1983. These patients were divided into three groups: group I, 25 infants with an intact ventricular septum who had primary repair in the first month of life (2 to 34 days of age, mean 9.7 +/- 6.6); group II, 13 patients with an intact ventricular septum who had anatomic repair after a preliminary procedure (pulmonary artery banding in 13, shunt in 10, atrial septectomy in 1); and group III, 15 infants with transposition of the great arteries and ventricular septal defect. In group III, six patients had Taussig-Bing abnormality, nine had previous pulmonary artery banding, three had coarctation of the aorta repaired earlier in life, and four were less than 2 weeks old. Overall early mortality was 9.4% (5/53: group I 8%, group II 7.6%, group III 13.3%). Two late deaths occurred in group II 10 and 12 weeks postoperatively after infection and high fever. A third late death 18 weeks postoperatively was due to aspiration in an infant with Goldenhar's syndrome. Mortality and morbidity decreased significantly after an initial learning period (no deaths from July 1985 to March 1987 overall, and none in the last 15 infants operated on in group I). The surviving 45 patients are doing well. All have normal sinus rhythm. Two had transient asymptomatic arrhythmias. Left and right ventricular function assessed by echocardiogram and postoperative cardiac catheterization were within normal ranges in all but two patients, one with pulmonary artery stenosis and one (Taussig-Bing abnormality with two large ventricular septal defects) with severe pulmonary vascular disease (9.6 units) observed before anatomic repair. The right ventricular pressure at catheterization ranged from 27 to 42 mm Hg in 12 patients and was 55 mm Hg in two. There was no aortic stenosis. Aortic insufficiency was trivial in three patients and mild in one. We conclude that excellent results can be obtained with arterial switch for transposition of the great arteries with or without ventricular septal defect, especially in neonates.