Achlya sp. Dermatitis in an American Alligator (Alligator mississippiensis).

Oomycetes are water moulds in the kingdom Protista and are not considered true fungi due to the structural lack of chitin and ergosterol. Many oomycetes are pathogenic, such as Pythium spp., and many fish are prone to Saprolegnia spp. infections, particularly in stressful farming situations. A juvenile American alligator (Alligator mississippiensis) was presented for necropsy examination with white, gelatinous, raised lesions over ulcerated regions of skin on the limbs and tail. The alligator came from a hatchery with age-divided enclosures, and several of the animals within the same enclosure showed similar lesions. Numerous hyphae with non-parallel walls and sparse, non-dichotomous branching were observed histologically on Gomori's methenamine silver staining within the ulcers. Although no organisms were detectable via polymerase chain reaction testing of fresh or formalin-fixed tissues, the organism was cultured and sequenced as an Achlya sp., an infrequently identified oomycete. To the author's knowledge, this is the first description of an oomycete infection within the class Reptilia.

In vitro susceptibility of equine-obtained isolates of Corynebacterium pseudotuberculosis to gallium maltolate and 20 other antimicrobial agents.

This study's objective was to determine the in vitro antimicrobial activities of gallium maltolate (GaM) and 20 other antimicrobial agents against clinical equine isolates of Corynebacterium pseudotuberculosis. The growth of cultured isolates was not inhibited by any concentration of GaM. MIC data revealed susceptibility to commonly used antimicrobials.

Isolation and characterization of a new fungal genus and species, Aphanoascella galapagosensis, from carapace keratitis of a Galapagos tortoise (Chelonoidis nigra microphyes).

A new fungal genus and species, Aphanoascella galapagosensis, recovered from carapace keratitis in a Galapagos tortoise residing in a south Texas zoological collection, is characterized and described. The presence of a pale peridium composed of textura epidermoidea surrounded by scarce Hülle cell-like chlamydospores, and the characteristic reticulate ascospores with an equatorial rim separates it from other genera within the Onygenales. The phylogenetic tree inferred from the analysis of D1/D2 sequences demonstrates that this fungus represents a new lineage within that order. As D1/D2 and ITS sequence data also shows a further separation of Aphanoascus spp. into two monophyletic groups, we propose to retain the generic name Keratinophyton for species whose ascospores are pitted and display a conspicuous equatorial rim, and thereby propose new combinations in this genus for four Aphanoascus species.

Mammographic appearance of the breasts during pregnancy and lactation: false assumptions.

RATIONALE AND OBJECTIVES: It is believed that pregnant and lactating women have dense breasts, thereby limiting the usefulness of mammography. To our knowledge, no reports have been published on this topic for nearly 4 decades. The purpose of our study was to determine whether this assumption is accurate given current state-of-the-art mammography. MATERIALS AND METHODS: Mammograms of 18 women (six pregnant, seven lactating, and five who recently discontinued lactation) were examined and compared with their baseline (before pregnancy or lactation) mammograms and with mammograms of 18 age-matched control subjects. Studies were scored for breast density according to the Breast Imaging Reporting and Data System and evaluated for change in density and size. RESULTS: Three of the six pregnant women had unchanged breast density compared with baseline studies and had scattered fibroglandular or heterogeneously dense tissue. Of the three without baseline studies, one had extremely dense, one had heterogeneously dense, and one had scattered fibroglandular tissue. All seven lactating women had either heterogeneously dense or extremely dense tissue. The breast tissue in four was unchanged in density and increased in two; no baseline study was available for the remaining patient. Seven studies in five women who had discontinued lactation 1 week to 5 months prior to mammography showed no change in density compared with baseline. CONCLUSION: Pregnant and lactating women do not always have dense breasts, and mammography can be performed without substantial concern for the limitations of breast density. Mammography can be as useful in these women as it is in other women with breast signs and symptoms.

The use of helical computed tomographic scan to assess bony physeal bridges.

Coronal and sagittal reformatted images of the physis obtained with the helical computed tomography (CT) scanner were studied in five children. This technique allows tomographic slices at 1.0-mm thickness and can be performed in approximately 20 s. The distal femora were studied in two children, the distal tibia in two children, and the distal radius in one child. In three children, after physeal mapping, bar resections were performed. In all cases, the location and size of the bar was accurately predicted by the map constructed from the helical CT scan. We recommend the helical CT scan to prepare physeal maps to determine the extent and location of physeal bony bars because of excellent bony detail, radiation doses one half to one quarter those of conventional tomography, and the rapidity of scanning, which bypasses the need for sedation.

Anatomic and sonographic features of the fetal skull.

This article reviews developmental skull anatomy, especially as it relates to the formation of cranial sutures and fontanelles, and demonstrates the appearance of these structures on prenatal sonograms, illustrating the framework these structures provide to enable one to accurately identify components of the fetal skull. Examples are provided to illustrate the utility of this knowledge. An understanding of fetal skull development and appearance enables the sonographer to better characterize fetal cranial abnormalities. More importantly, recognition of the location of cranial sutures and fontanelles and their ability to serve as acoustic windows assists the sonographer in evaluation of the fetal brain.

Innovations in human genetics education. Incorporation of genetics into a problem-based medical school curriculum.

There has been recent interest in the development of problem-based human genetics curricula in U.S. medical schools. The College of Human Medicine at Michigan State University has had a problem-based curriculum since 1974. The vertical integration of genetics within the problem-based curriculum, called "Track II," has recently been revised. On first inspection, the curriculum appeared to lack a significant genetics component; however, on further analysis it was found that many genetics concepts were covered in the biochemistry, microbiology, pathology, and clinical science components. Both basic science concepts and clinical applications of genetics are covered in the curriculum by providing appropriate references for basic concepts and including inherited conditions within the differential diagnosis in the cases studied. Evaluations consist of a multiple-choice content exam and a modified essay exam based on a clinical case, allowing evaluation of both basic concepts and problem-solving ability. This curriculum prepares students to use genetics in a clinical context in their future careers.

Apparently previously undescribed X-linked dominant syndrome with facial and skeletal anomalies.

We report on a syndrome of widow's peak, ptosis, skeletal abnormalities and other minor anomalies in a large family. The condition appears to be inherited in an X-linked dominant fashion. No similar cases have been found in the literature, suggesting that this is a "new" syndrome. Study of 5 generations of the family documents information on the natural history of the condition.

Renal tubular dysgenesis: delayed onset of oligohydramnios.

Two premature sibs had Potter sequence and died of respiratory failure within the first day. Ultrasonography at 26 weeks during the earlier of the two pregnancies showed complete absence of amniotic fluid, and the urinary bladder was not visualized. Ultrasound examinations during the second pregnancy showed adequate amniotic fluid at 16 and 20 weeks, with a subsequent reduction in fluid volume. Two older sibs had also died of respiratory failure shortly after birth. Postmortem histopathologic studies showed all four sibs to have severely deficient renal tubular development. However, the presence of numerous glomeruli indicated prolific nephrogenesis. Most of the tubules in sections of cortex had the lectin-binding and immunohistochemical characteristics of collecting ducts; proximal tubules were not identified by lectin-binding. Electron-microscopic examination showed a general absence of differentiated characteristics in cortical tubular epithelium, except that rare tubules contained rudimentary proximal tubular brush borders. Three of the sibs were boys, one a girl. The three children that were studied had normal chromosomes. Two unaffected sibs are alive and well. Neither parent has any clinical evidence of renal disease. These studies support the interpretation that renal tubular dysgenesis is autosomal recessive with pleiotropy. However, the relatively late appearance of oligohydramnios makes early diagnosis difficult, even when the condition is suspected.

Alterations in the Ca2+ sensitivity of tension development by single skeletal muscle fibers at stretched lengths.

The apparent length dependence in the calcium sensitivity of tension development in skeletal muscle has been investigated in the present study. At sarcomere lengths of 2.46-2.62 micron, the Hill plot of tension-pCa data is well fit by not one but two straight lines, suggesting the possible involvement of more than a single class of Ca2+-binding site in tension development. On the other hand, increasing the sarcomere length to 3.00-3.25 micron yielded Hill plots that were described by a single straight line, which indicates that at long lengths tension might be regulated by the binding of Ca2+ to a single class of Ca2+-binding sites, presumably the low affinity sites of TnC. This length-dependent transformation of the tension pCa relation occurred at free Mg2+ concentrations of both 0.05 and 3.2 mM. Although the mechanism of this effect is uncertain, plausible explanations for the biphasic Hill plot at the shorter lengths include the possible involvement of Ca2+ activation of the thick filaments and/or myosin LC2 phosphorylation in the process of tension development.