NPAS2: an analog of clock operative in the mammalian forebrain

Neuronal PAS domain protein 2 (NPAS2) is a transcription factor expressed primarily in the mammalian forebrain. NPAS2 is highly related in primary amino acid sequence to Clock, a transcription factor expressed in the suprachiasmatic nucleus that heterodimerizes with BMAL1 and regulates circadian rhythm. To investigate the biological role of NPAS2, we prepared a neuroblastoma cell line capable of conditional induction of the NPAS2:BMAL1 heterodimer and identified putative target genes by representational difference analysis, DNA microarrays, and Northern blotting. Coinduction of NPAS2 and BMAL1 activated transcription of the endogenous Per1, Per2, and Cry1 genes, which encode negatively activating components of the circadian regulatory apparatus, and repressed transcription of the endogenous BMAL1 gene. Analysis of the frontal cortex of wild-type mice kept in a 24-hour light-dark cycle revealed that Per1, Per2, and Cry1 mRNA levels were elevated during darkness and reduced during light, whereas BMAL1 mRNA displayed the opposite pattern. In situ hybridization assays of mice kept in constant darkness revealed that Per2 mRNA abundance did not oscillate as a function of the circadian cycle in NPAS2-deficient mice. Thus, NPAS2 likely functions as part of a molecular clock operative in the mammalian forebrain.

Statistical parameters in behavioral tasks and implications for sample size of C57BL/6J:129S6/SvEvTac mixed strain mice

Most mixed strain progeny from gene-knockout experiments typically originate from C57BL/6J and one of the 129 substrains, frequently 129S6/SvEvTac. The results of this behavioral survey suggest that C57BL/6J:129S6/SvEvTac mixed strain mice are amenable to behavioral testing. The variability in behavioral tasks for subjects arising from this mixed strain genetic background does not preclude screening with a battery of behavioral tests. With clues provided by a screen of mixed strain subjects, follow-up analyses with isogenic, congenic, or F1 hybrid animals may be targeted to specific behavioral themes.

Demyelination but no cognitive, motor or behavioral deficits after adenovirus-mediated gene transfer into the brain

Adenovirus-mediated gene transfer of interferon gamma (AdIFN) elicits rejection of intracerebral Lewis lung carcinoma. In this system, gene transfer into brain parenchymal cells is both necessary and sufficient to generate the antitumor response. Despite persistent parenchymal inflammation and demyelination, wild-type mice injected intracerebrally with either AdIFN or beta-galactosidase adenovirus (AdBGAL) perform as well as non-injected animals in behavioral, memory, and motor tests. Both AdIFN and AdBGAL elicit demyelination whose incidence rises sharply when the lowest effective dose of AdIFN is exceeded. Therefore, transfer of interferon gamma into brain parenchyma does not seem to elicit detectable cognitive, behavioral or motor deficits. Furthermore, gene transfer into the brain, by adenoviral vectors currently in clinical trials, is associated with a narrow therapeutic window where the incidence of demyelination rises sharply soon after the effective dose is achieved. Gene Therapy (2000) 7, 2094-2098.

A marker assisted selection protocol (MASP) to generate C57BL/6J or 129S6/SvEvTac speed congenic or consomic strains

A marker assisted selection protocol is presented that allows for the generation of congenic or consomic strains derived from a C57BL/6J:129S6/SvEvTac mixed strain background. The protocol uses defined primer pairs to generate amplicons that can be distinguished by non-denaturing agarose electrophoresis. Use of this application should result in substantial savings in time, effort, and cost for investigators in all areas of transgenic mouse research.

Lack of toxicity to adults of the Mexican fruit fly (Diptera: Tephritidae) of beta-exotoxin in Bacillus thuringiensis endotoxin preparations

beta-Exotoxin (thuringiensin) was found in high titers in centrifugation supernatants and acetone/lactose powders produced from centrifugation pellets of strains Guat 1 and HD 2 of Bacillus thuringiensis (Berliner). Diets containing powders of either strain were toxic, diets containing Guat 1 supernatant were not toxic, diets containing HD 2 supernatant were slightly toxic, and diets containing powders or supernatants from uninoculated culturing medium spiked with beta-exotoxin were not toxic. Most mortality occurred within 3 d when flies fed on powders but not until 6-7 d when flies fed on HD 2 supernatant. These results indicated that the primary toxic principals of the powders were endotoxins/spores and that beta-exotoxin alone was not toxic to adult flies at the concentrations found in the supernatants or powders.

Impaired cued and contextual memory in NPAS2-deficient mice

Neuronal PAS domain protein 2 (NPAS2) is a basic helix-loop-helix (bHLH) PAS domain transcription factor expressed in multiple regions of the vertebrate brain. Targeted insertion of a beta-galactosidase reporter gene (lacZ) resulted in the production of an NPAS2-lacZ fusion protein and an altered form of NPAS2 lacking the bHLH domain. The neuroanatomical expression pattern of NPAS2-lacZ was temporally and spatially coincident with formation of the mature frontal association/limbic forebrain pathway. NPAS2-deficient mice were subjected to a series of behavioral tests and were found to exhibit deficits in the long-term memory arm of the cued and contextual fear task. Thus, NPAS2 may serve a dedicated regulatory role in the acquisition of specific types of memory.

The efficacy of cyanoacrylate-derived surgical adhesive for use in the repair of lacerations during competitive athletics

Octylcyanoacrylate (Dermabond) is approved by the Food and Drug Administration for laceration closure. International studies have shown its utility in wound closure and have shown it to be as good or better than suture closure for speed, patient preference, and cosmesis, with no difference in the rate of dehiscence or infection. We sought to determine whether it retains its tensile strength, durability, and skin apposition when an athlete is allowed to reenter competition, where it is subject to recurrent stress, moisture, and trauma. The study was performed at two professional hockey sites. Wounds were anesthetized, irrigated, and debrided. The skin was closed with Dermabond. The athlete was returned immediately to competition. Wounds were examined at the end of competition and again at 7 days. A total of 32 lacerations on 28 players were studied. The mean size of laceration was 2.3 cm (range 0.8 cm to 4.5 cm). The majority (95%) of wounds were on the face. Of the 32 lacerations, 31 (97.6%) had good results at the conclusion of the game. Of these 31, all had good results at 7 days following repair. Dermabond retained its strength, durability, and skin apposition when the athlete was allowed to reenter competition following wound repair.

Assessing bilingual and monolingual Latino students with translations of the MMPI-2: initial data

This article presents the results of 2 studies conducted with Spanish versions of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) with Latino students. Study 1 compared the results of 2 administrations of the MMPI-2, one in English and the other in Spanish. Study 2 compared the results of administrations of 2 Spanish versions of the MMPI-2, the official Mexican adaptation and the Version Hispana. In both cases, scale score differences were not found. Comparability, as operationally defined by test-retest reliability, was found to be higher for the group that was administered the English and Spanish versions than the group administered the 2 Spanish versions. Overall, the results were found to suggest correspondence. Yet, the authors warn against concluding "perfect" correspondence because other key groups need to be studied, including psychiatric patients and persons from the Latino community. Also, the determination of linguistic equivalence needs further refinement.

The role of the right ventricle during hypobaric hypoxic exercise: insights from patients after the Fontan operation

OBJECTIVES

The principal objective of this study was to examine the importance of the right ventricle for maximal systemic oxygen transport during exercise at high altitude by studying patients after the Fontan operation.

BACKGROUND

High-altitude-induced hypoxia causes a reduction in maximal oxygen uptake. Normal right ventricular pump function may be critical to sustain cardiac output in the face of hypoxic pulmonary vasoconstriction. We hypothesized that patients after the Fontan operation, who lack a functional subpulmonary ventricle, would have a limited exercise capacity at altitude, with an inability to increase cardiac output.

METHODS

We measured oxygen uptake (VO2, Douglas bag), cardiac output (Qc, C2H2 rebreathing), heart rate (HR) (ECG), blood pressure (BP) (cuff), and O2 Sat (pulse oximetry) in 11 patients aged 14.5+/-5.2 yr (mean +/- SD) at 4.7+/-1.6 yr after surgery. Data were obtained at rest, at three submaximal steady state workrates, and at peak exercise on a cycle ergometer. All tests were performed at sea level (SL) and at simulated altitude (ALT) of 3048 m (10,000 ft, 522 torr) in a hypobaric chamber.

RESULTS

At SL, resting O2 sat was 92.6+/-4%. At ALT, O2 sat decreased to 88.2+/-4.6% (P < 0.05) at rest and decreased further to 80+/-6.3% (P < 0.05) with peak exercise. At SL, VO2 increased from 5.1+/-0.9 mL x kg(-1) x min(-1) at rest to 23.5+/-5.3 mL x kg(-1) x min(-1) at peak exercise and CI (Qc x m(-2)) increased from 3.3+/-0.7 L x m(-2) to 6.2+/-1.2 L x m(-2). VO2 peak, 17.8+/-4 mL x kg(-1) x min(-1) (P < 0.05), and CI peak, 5.0+/-1.5 L x m(-2) (P < 0.05), were both decreased at ALT. Remarkably, the relationship between Qc and VO2 was normal during submaximal exercise at both SL and ALT. However at ALT, stroke volume index (SVI, SV x m(-2)) decreased from 37.7+/-8.6 mL x min(-1) x m2 at rest, to 31.3+/-8.6 mL x min(-1) x m2 at peak exercise (P < 0.05), whereas it did not fall during sea level exercise.

CONCLUSIONS

During submaximal exercise at altitude, right ventricular contractile function is not necessary to increase cardiac output appropriately for oxygen uptake. However, normal right ventricular pump function may be necessary to achieve maximal cardiac output during exercise with acute high altitude exposure.

Ribotyping and plasmid profiling of Yersinia ruckeri

A total of 183 strains of Yersinia ruckeri, isolated from a wide variety of sources, were studied with respect to their plasmid profile and ribotype patterns. Eight plasmid profiles and 11 ribotypes were demonstrated, with one profile being predominant by both typing methods. The results suggest a clonal structure for this species, with a predominant clone being responsible for most of the outbreaks worldwide. The results of a long-time survey in several fish farms in Spain and Denmark seem to support this idea.

Usefulness of Doppler echocardiography in diagnosing right ventricular coronary arterial communications in patients with pulmonary atresia and intact ventricular septum and comparison with angiography

Direct and indirect evidence of right ventricular coronary arterial communications has been detected by use of 2-dimensional and Doppler echocardiography in patients with pulmonary atresia and intact ventricular septum. We describe additional consistent and reproducible Doppler echocardiographic findings that were useful for identifying patients in whom abnormal coronary arterial flow patterns were detected angiographically.

Enalapril does not enhance exercise capacity in patients after Fontan procedure

BACKGROUND

Angiotensin-converting enzyme inhibitors improve exercise capacity in adults with congestive heart failure by decreasing systemic vascular resistance and improving ventricular diastolic function. Patients who have undergone the Fontan procedure have decreased cardiac output, increased systemic vascular resistance, abnormal diastolic function, and decreased exercise capacity compared with normal people.

METHODS AND RESULTS

To test the hypothesis that afterload reduction therapy alters hemodynamic variables and augments exercise capacity in patients after a Fontan procedure, we compared the results of graded exercise with maximal effort from 18 subjects (14.5+/-6.2 years of age, 4 to 19 years after Fontan procedure) in a randomized, double-blind, placebo-controlled crossover trial using enalapril (0.2 to 0.3 mg x kg[-1] x d[-1], maximum 15 mg). Each treatment was administered for 10 weeks. Diastolic filling patterns at rest were assessed by Doppler determination of the systemic atrioventricular valve flow velocity at the conclusion of each therapy. No difference was detected in resting heart rate, blood pressure, or cardiac index. Diastolic filling patterns were also similar. Exercise duration was not different (6.4+/-2.6 [enalapril] versus 6.7+/-2.6 minutes [placebo]). The mean percent increase in cardiac index from rest to maximum exercise was slightly but significantly decreased in subjects after 10 weeks of enalapril therapy (102+/-34% [enalapril] versus 125+/-34% [placebo]; P<.02). At maximal exercise, cardiac index (3.5+/-0.9 [enalapril] versus 3.8+/-0.9 L x min[-1] x m2 [placebo]), oxygen consumption (18.3+/-9 [enalapril] versus 20.5+/-7 mL x min[-1] x kg[-1] [placebo]), minute ventilation (57.5+/-17 [enalapril] versus 55.4+/-19 L/min [placebo]), and total work (247+/-181 [enalapril] versus 261+/-197 W [placebo]) were not different.

CONCLUSIONS

We conclude that enalapril administration for 10 weeks does not alter abnormal systemic vascular resistance, resting cardiac index, diastolic function, or exercise capacity in patients who have undergone a Fontan procedure.

Mechanisms for increasing stroke volume during static exercise with fixed heart rate in humans

Ten patients with preserved inotropic function having a dual-chamber (right atrium and right ventricle) pacemaker placed for complete heart block were studied. They performed static one-legged knee extension at 20% of their maximal voluntary contraction for 5 min during three conditions: 1) atrioventricular sensing and pacing mode [normal increase in heart rate (HR; DDD)], 2) HR fixed at the resting value (DOO-Rest; 73 +/- 3 beats/min), and 3) HR fixed at peak exercise rate (DOO-Ex; 107 +/- 4 beats/min). During control exercise (DDD mode), mean arterial pressure (MAP) increased by 25 mmHg with no change in stroke volume (SV) or systemic vascular resistance. During DOO-Rest and DOO-Ex, MAP increased (+25 and +29 mmHg, respectively) because of a SV-dependent increase in cardiac output (+1.3 and +1.8 l/min, respectively). The increase in SV during DOO-Rest utilized a combination of increased contractility and the Frank-Starling mechanism (end-diastolic volume 118-136 ml). However, during DOO-Ex, a greater left ventricular contractility (end-systolic volume 55-38 ml) mediated the increase in SV.

Treatment of bleb leaks with transforming growth factor-beta in the rabbit model

PURPOSE

The mechanism through which peribleb injection of autologous blood results in resolution of bleb leak in the rabbit model remains unclear. This study evaluates the clinical and histologic effects of peribleb injection of transforming growth factor-beta (TGF-beta) after leak induction in mitomycin-C-treated blebs.

METHOD

Posterior lip sclerectomies treated with mitomycin-C were created in New Zealand White rabbits. On postoperative day 7, a standardized stab incision was performed on all blebs, and the eyes were randomized to receive a peribleb injection of either TGF-beta or of a balanced salt solution.

RESULTS

Injection of TGF-beta was associated with the resolution of bleb leak and maintenance of a functioning bleb in 50% (4 of 8) of treated eyes. The remaining TGF-beta-treated eyes and control eyes demonstrated continued bleb leaks or bleb failures with intraocular pressure returning to preoperative levels. Histologic examination revealed increased peribleb cellularity and denser collagen deposition in the TGF-beta-treated eyes compared with that observed in control eyes.

CONCLUSIONS

Peribleb TGF-beta injections may contribute to healing bleb leaks, but the injections do not appear in this model to be as useful as whole-blood injections.

Unconventional myosins in inner-ear sensory epithelia

To understand how cells differentially use the dozens of myosin isozymes present in each genome, we examined the distribution of four unconventional myosin isozymes in the inner ear, a tissue that is particularly reliant on actin-rich structures and unconventional myosin isozymes. Of the four isozymes, each from a different class, three are expressed in the hair cells of amphibia and mammals. In stereocilia, constructed of cross-linked F-actin filaments, myosin-Ibeta is found mostly near stereociliary tips, myosin-VI is largely absent, and myosin-VIIa colocalizes with crosslinks that connect adjacent stereocilia. In the cuticular plate, a meshwork of actin filaments, myosin-Ibeta is excluded, myosin-VI is concentrated, and modest amounts of myosin-VIIa are present. These three myosin isozymes are excluded from other actin-rich domains, including the circumferential actin belt and the cortical actin network. A member of a fourth class, myosin-V, is not expressed in hair cells but is present at high levels in afferent nerve cells that innervate hair cells. Substantial amounts of myosins-Ibeta, -VI, and -VIIa are located in a pericuticular necklace that is largely free of F-actin, squeezed between (but not associated with) actin of the cuticular plate and the circumferential belt. Our localization results suggest specific functions for three hair-cell myosin isozymes. As suggested previously, myosin-Ibeta probably plays a role in adaptation; concentration of myosin-VI in cuticular plates and association with stereociliary rootlets suggest that this isozyme participates in rigidly anchoring stereocilia; and finally, colocalization with cross-links between adjacent stereocilia indicates that myosin-VIIa is required for the structural integrity of hair bundles.

Toxicity of an isolate of Bacillus thuringiensis subspecies darmstadiensis to adults of the Mexican fruit fly (diptera: (Diptera:Tephritidae) in the laboratory

Centrifugation pellets obtained from an isolate of Bacillus thuringiensis subspecies darmstadiensis (Guat 1) cultured from a Guatemalan soil sample were found to be toxic to Anastrepha ludens (Loew) adults in the laboratory. We developed a bioassay diet that consisted of a mixture of the bacterium, a protein source, and sugar. A pH of 4.1 of the mixture was needed to obtain maximum adult mortality. One meal of the diet, which lasted from 30 s to 4 min, was enough to cause > 70% mortality of both fed or starved adults. Mortality of fed adults was 70-75% following a feeding period of 60 min and mortality of starved adults was 80-90% following a feeding period of 30 min. The isolate was toxic to adults from 1 to 21 d old.

Urethral caruncle with atypical stromal cells simulating lymphoma or sarcoma--a distinctive pseudoneoplastic lesion of females. A report of six cases

Six urethral caruncles in women aged 32 to 82 (average, 56) years contained atypical stromal cells raising concern for a neoplasm. The atypical cells varied from spindled to round, the latter predominating, and typically had scant cytoplasm. A minority of the cells were binucleated or multinucleated and often had prominent nucleoli. A single mitotic figure was found in the atypical cells in one case. The atypical cells were characteristically present in an edematous background containing numerous inflammatory cells and were focally crowded together in five cases. The differential diagnosis in these cases included a florid reactive proliferation of lymphoid cells, but immunohistochemical stains failed to support a lymphoid nature for the atypical cells and also helped to exclude malignant lymphoma, the neoplasm most often simulated. Because of the invariable additional component of atypical spindle cells resembling those described in the stroma of the lower female genital tract and in polyps in a variety of sites, the round cells likely represent a variant of this atypical mesenchymal cell. Similar round mesenchymal cells have also been documented in the gastrointestinal tract, especially the stomach. Immunohistochemical stains in this series showed them to be positive for vimentin in four of four cases and for alpha smooth-muscle actin in two of four cases. The prominence of atypical round stromal cells in these cases appears to be a distinctive feature of some urethral caruncles. The presence of these cells should not lead to misinterpretation of the lesion as a neoplastic process.

Injection of autologous blood for bleb leaks in New Zealand white rabbits

PURPOSE

Bleb leaks after trabeculectomy with antimetabolites can be recalcitrant to therapy. Peribleb autologous blood injections are a moderately successful new treatment modality for such leaks. However, it is unclear what mechanism the injections work to achieve leak resolution.

METHODS

A randomized, prospective study in the rabbit model was undertaken to evaluate further the clinical and histologic effects of peribleb autologous blood injection after leak induction in mitomycin-C exposed blebs, compared to controls that received only peribleb balanced salt solution injections.

RESULTS

In the blood-treated eyes, all bleb leaks healed. Control eyes either demonstrated persistent bleb leaks with shallow anterior chambers or failed blebs that were Seidel negative. Histologic results were remarkable for increased peribleb cellularity and collagen deposition in the blood-treated eyes, compared to controls.

CONCLUSIONS

Peribleb autologous blood injections are associated with bleb leak resolution, increased peribleb cellularity, and collagen deposition in the rabbit model.

Atypical cutaneous changes after topical treatment with nitrogen mustard in patients with mycosis fungoides

Side effects in the treatment of mycosis fungoides with topical nitrogen mustard include allergic contact dermatitis, hyperpigmentation, urticaria, and erythema multiforme-like dermatitis. We reviewed biopsy specimens from 10 patients with mycosis fungoides who were treated with topical nitrogen mustard for 10-76 months. There was no history of oral psoralen with long-wave UV radiation treatment, radiotherapy, or systemic chemotherapy. Control biopsies taken from erythematous or poikilodermatous patches on the trunk or proximal extremities showed epidermal and dermal changes associated with cytologic atypia that were not present before treatment. These changes included slight epidermal hyperplasia with foci of flat rete ridges, atypical keratinocytes with large nuclei, mostly in the lower portion of the epidermis; suprabasal mitotic figures; a few dyskeratotic cells, focal vacuolar alteration of the epidermal basal layer; increased number of slightly enlarged junctional melanocytes; melanophages in the papillary dermis; dilated blood vessels lined by plump, atypical endothelial cells; and large fibroblasts with atypical nuclei. These atypical histologic changes resemble, in part, those described in association with systemic chemotherapeutic agents, such as etoposide, busulfan, and bleomycin. We conclude that topical nitrogen mustard should be added to the list of chemotherapeutic agents that can produce atypical histologic changes in the skin.

Cardiovascular responses at the onset of static exercise in patients with dual-chamber pacemakers

Cardiac output (CO) responses to exercise can be altered by ventricular pacing in pacemaker-dependent patients. The relative contributions of CO and peripheral vascular resistance (PVR) toward the initial increase in blood pressure with the initiation of static exercise were investigated in eight otherwise healthy pacemaker-dependent subjects [age 24 +/- 2 yr (range 17-37 yr)]. Beat-by-beat measures of heart rate (HR; electrocardiography), mean arterial pressure (MAP), and CO derived from stroke volume (SV) (CO = HR.SV; 2-D echocardiography) were determined during the first 20 s of a one-legged static knee extension performed at 20% maximal voluntary effort by using three pacing modalities: dual pacing and sensing mode (DDD, i.e., normal physiological HR response), fixed at resting HR (DOO-R), and fixed at peak exercise HR (DOO-E), as previously achieved during 5 min of sustained contraction in the DDD mode. There were no differences in MAP, CO, or PVR (PVR = MAP/CO) between modes at rest (P > 0.05). With DOO-E pacing, SV was lower at rest compared with the other modes and increased with exercise (P < 0.05). Although there were no significant increase in MAP or CO during DOO-R pacing, both variables were elevated by leg contraction during DDD and DOO-E pacing (P < 0.05), with no significant change in PVR. Additionally, the CO and MAP increases were significantly greater with DOO-E pacing (P < 0.05). Thus the magnitude of the initial increase in arterial pressure at the onset of mild one-legged static exercise was dictated by the changes in CO as PVR remained unchanged.

Properties of the active plum pox potyvirus RNA polymerase complex in defined glycerol gradient fractions

As a first step in the study of the replication of plum pox virus (PPV) RNA, an in vitro virus-specific RNA polymerase activity was characterized in a crude membrane extract (Martin and Garcia, 1991). In this study, we report the fractionation of the crude membrane extract by centrifugation in glycerol gradients. The sedimentation properties after different treatments of the crude extract and its insensitivity to micrococcal nuclease treatment suggest that the RNA polymerase activity was localized in a defined and enclosed membranous structure. Subcellular membrane characterization of the different glycerol gradient fractions indicated that PPV-specific RNA synthesis occurred in fractions enriched in endoplasmic reticulum and tonoplast vesicles.

Pleomorphic basal cell carcinoma

BACKGROUND

A variant of basal cell carcinoma (BCC) with scattered large, pleomorphic cells has previously been reported as "basal cell epithelioma with giant tumor cells" and "basal cell carcinoma with monster cells."

OBJECTIVE

Our purpose was to describe the clinical, histologic, and DNA ploidy findings in BCCs with these cytologic features.

METHODS

Nineteen pleomorphic BCCs from 15 patients were prospectively collected, and other BCCs in these patients were retrospectively reviewed by light microscopy. One lesion was recurrent. Seven of the pleomorphic BCCs and one nonpleomorphic BCC were studied by image analysis.

RESULTS

These pleomorphic BCCs ranged from 2.8 to 12.5 mm in greatest diameter and were most commonly located on the head and neck. Five BCCs were present on the face and scalp of a patient with basal cell nevus syndrome. There have been no subsequent recurrences of the pleomorphic BCCs (follow-up from 3 to 32 months; median, 20 months). All 19 pleomorphic BCCs displayed characteristic features of BCC: peripheral palisading, stromal retraction, mucin production, and apoptosis. All 19 also showed huge pleomorphic mononucleated and multinucleated giant tumor cells. The nuclei of these large cells were often hyperchromatic with prominent nucleoli and abundant cytoplasm, and occasionally with intranuclear cytoplasmic protrusions. In addition, there were frequent and atypical mitoses in 47% of the cases. All pleomorphic BCCs studied by cell image analysis of formalin-fixed, paraffin-embedded tissue were aneuploid. The DNA content of the giant tumor cells was not a multiple of a single DNA value.

CONCLUSION

Pleomorphic BCCs clinically present as typical BCCs. Despite their striking focal cellular atypia, these lesions seem to behave as ordinary BCCs.

Cutaneous infection caused by Curvularia pallescens: a case report and review of the spectrum of disease

A 75-year-old woman being treated with prednisone and methotrexate had a 5.5 x 2.2 cm ulcer on the leg. A biopsy specimen revealed suppurative, granulomatous dermal inflammation with necrotic areas of septate, branching hyphae containing brown pigment. Cultures grew Curvularia pallescens. Oral ketoconazole therapy was started and the lesion was excised. The site healed after multiple excisions and grafts, and ketoconazole therapy was stopped after 7 months. This is the first reported case of invasive cutaneous infection by C. pallescens.

Echocardiographic diagnosis of discontinuous left pulmonary artery as an isolated lesion

The diagnosis of a discontinuous left pulmonary artery arising from a left ductus arteriosus was made by two-dimensional and Doppler echocardiography in an infant with recurrent pneumonia. The diagnosis was later confirmed at cardiac catheterization and surgery. The suprasternal notch views were especially useful for the identification of the left pulmonary artery. In this patient with a right aortic arch, the left pulmonary artery was supplied by a left ductus arteriosus that arose from the innominate artery. This case report describes the echocardiographic diagnosis of discontinuous left pulmonary artery as an isolated lesion, an unusual lesion that can easily be missed. It emphasizes the necessity of a careful and complete examination with particular emphasis on pulmonary artery continuity in patients suspected of having congenital heart disease or respiratory compromise as a result of a cardiovascular cause.