Acute otomastoiditis and its complications: role of CT

Acute bacterial (suppurative) otomastoiditis responds to antibiotic treatment; radiologic study is required only when there is clinical suggestion of coalescent mastoiditis, intracranial complications, or an underlying chronic disease. Computed tomography (CT) is the method of choice for evaluating otogenic intra- or extra-cranial complications. CT scans can show stages of disease progression when infection has spread by way of soft tissue, blood, and bone pathways into the dural venous sinuses, meninges, labyrinth, facial nerves, epidural and other intracranial spaces. When there is clinical suggestion of acute coalescent mastoiditis, a CT scan of the temporal bone can confirm the presence of rarefying osteitis, coalescence of the air cells, and subperiosteal abscess.     

Cutaneous malignant mixed tumor

Two cases of cutaneous malignant mixed tumor occurred in a 70-year-old man and a 69-year-old man. Nine previously described patients with cutaneous malignant mixed tumor resembled the two patients in this report, both clinically and histologically. All cases with adequate long-term follow-up evaluations were characterized by recurrence or metastasis. In contrast to benign mixed tumors, these tumors tend to occur on the extremities, are of larger size, and may exhibit rapid growth. Histologically, cellular atypism, increased cellularity, increased mitotic rate, invasion of surrounding tissue, and necrosis may be identified.     

Dysplastic melanocytic nevi: a reproducible histologic definition emphasizing cellular morphology

Histologic criteria commonly used to diagnose dysplastic melanocytic nevi (DMN) have not been correlated adequately with biology nor subjected to rigorous reproducibility studies. To address these failings, we developed histologic definitions emphasizing cellular morphology based on the appearance of typical melanocytes in sun-protected buttock skin, fully-evolved atypia in the vertical component of metastasizing primary cutaneous melanomas, and slight and moderate degrees of atypia defined within these limits in selected varieties of DMN. Reproducibility of our histologic definitions were tested by using two pathologists working independently to assess single routine tissue sections of 19 melanocytic lesions on two occasions at least 6 mo apart. Lesions included five previously diagnosed primary invasive cutaneous melanomas, seven lesions selected for gross morphologic features characteristic of DMN, and four solar lentigines and three common acquired nevomelanocytic nevi preselected for typical appearance and stable growth history. For the primary pathologist using the grading scheme, agreement rates between first and second readings were 84% for final diagnosis and 79% for the highest degree of cellular atypia; for the secondary pathologist, agreement rates for first and second readings for both parameters were 84%. Agreement rates comparing second readings of final diagnosis and highest degree of cellular atypia by the two pathologists were 89% and 79%, respectively. Most of the architectural and host response features commonly associated with DMN were less reproducible. In conclusion, we demonstrated very good reproducibility of histologic definitions used to differentiate the intraepidermal component of DMN from that of melanoma and benign melanocytic and nevomelanocytic hyperplasias, based on a biologic correlation emphasizing cellular morphology. Reproducible histologic definitions are a requisite first step in defining a clinical-pathologic correlation for DMN.     

Integrin expression in malignant melanoma and their role in cell attachment and migration on extracellular matrix proteins.

The interaction between melanoma cells and extracellular matrix (ECM) components may be important for invasion and metastasis. The integrins belong to a family of protein heterodimers composed of alpha and beta subunits and the beta 1-integrins are especially important as ECM receptors. We investigated the expression of beta 1-integrins on four human melanoma cell lines (two primary, one from the radial growth phase (RGP) and another from the vertical growth phase (VGP), and two metastatic) and examined their attachment and migration on laminin (LN), type IV collagen (CN) and fibronectin (FN). Among LN and/or CN integrin receptors, only alpha 2 beta 1 (VLA2) was expressed at significantly higher levels in the VGP and metastatic cell lines in comparison to the RGP cell line. In addition, enhanced attachment and migration on LN and CN were significantly inhibited by anti-VLA2 monoclonal antibody (mAb). As to FN receptors, alpha 4 beta 1 and alpha 5 beta 1 expression was heterogeneous among the cell lines, however, it was directly related to enhanced attachment and migration on FN, which also could be inhibited by anti-VLA4 and anti-VLA5 mAbs. Our findings provide evidence for a role in beta 1-integrins, in particular alpha 2 beta 1, in melanoma progression and metastasis.     

In vitro pharmacodynamics of ceftazidime against Pseudomonas aeruginosa isolates from cystic fibrosis patients.

The concentration/MIC (C/MIC) ratio maximizing the bactericidal activity of ceftazidime against 10 Pseudomonas aeruginosa isolates from cystic fibrosis patients was identified. Bactericidal activity was assessed by determining the percent difference in the area under the killing curve at each C/MIC ratio for all of the isolates from that of their growth control. The percent effect at each C/MIC ratio was fitted to a sigmoidal Emax model with maximum bactericidal activity defined as the C/MIC ratio that produced an effect that was 90% of the Emax. Our results suggest that at least some isolates may require higher C/MIC ratios than previously reported for maximal activity.     

Low seminal zinc bound to high molecular weight proteins in asthenozoospermic patients: evidence of increased sperm zinc content in oligoasthenozoospermic patients [published erratum appears in Hum Reprod 1998 Jun;13(6):1750]

Total seminal zinc concentration, seminal zinc fraction bound to high molecular weight proteins (HMW-Zn%) and zinc content in spermatozoa were assayed in the ejaculates of 90 asthenozoospermic patients subdivided into two study groups: normoasthenozoospermics (group I: n = 50) and oligoasthenozoospermics (group II: n = 40). The zinc concentrations of patients were compared with those of a control group of donors showing normal semen parameters. All samples were also investigated for their sperm membrane functional integrity by the hypo- osmotic swelling test (HOS). The results showed normal total zinc concentrations but very low HMW-Zn% values (P < 0.001) in seminal plasma of the two groups of asthenozoospermic patients compared to the controls. Furthermore higher zinc amounts (P < 0.001) were measured in spermatozoa of oligoasthenozoospermic patients compared to group I and to the control group. Oligoasthenozoospermics also displayed a lower HOS score (P < 0.001) compared to the other two groups. These data suggest that the increased unbound seminal zinc could contribute to the decrease of sperm motility in normoasthenozoospermic and oligoasthenozoospermic patients. A further impairment in sperm motility could occur in the oligoasthenozoospermic patients where the increase of seminal free zinc was followed by a major zinc uptake by spermatozoa. The higher intrasperm zinc content in these patients could be a reflection of their low sperm membrane functionality.