URETHRAL OBSTRUCTION SECONDARY TO HYPERPLASIA OF SEMINAL VESICLE GLANDS IN AN INTACT MALE AFRICAN PYGMY HEDGEHOG (Atelerix albiventris)

We studied the susceptibility of five germfree inbred strains of mice to oral infection by murine pathogenic Escherichia coli O115a,c:K(B) (MPEC), the causative agent of mouse megaenteron. Although MPEC colonized all strains of mice at 10(9)/g of feces, the mouse strains could be divided into three groups according to their intestinal lesions. In CF1 and C3H/He mice, intestinal lesions were produced in the cecum and colon with hyperplasia of epithelial cells accompanied by severe inflammatory reactions and erosion. The lesions in NC and C57BL/6 mice were restricted to the tip of the cecum, and hyperplasia of epithelial cells was more severe in these mice than in CF1 or C3H/He mice. BALB/c mice had no lesions. Analysis of F1 hybrids of CF1, NC, and BALB/c mice and offsprings from backcrosses of F1 mice to parental strains showed that susceptibility to MPEC seemed to be controlled genetically by a single locus which may be related to the receptors on epithelial cells for MPEC adherence. However, the differences in lesions between CF1 and NC mice suggest that a combination of this locus and another locus to which it may be related regulates the hyperplasia of intestinal epithelial cells.

A 37-year-old woman presented with a 6 week history of pruritic targetoid lesions, which were violaceous, erythematous plaques in an annular pattern, 1–2 cm in size, on both palms (Fig. 1). She had no prior history of medication or herpes simplex infection before the skin lesions occurred. All other physical findings were normal. The clinical findings suggested EM. Skin biopsy performed on the palm was consistent with interface dermatitis, and showed hyperkeratosis, lymphocytic exocytosis, and vacuolization of the basal layer. A mild perivascular lymphohistiocytic infiltrate without plasma cells was present throughout the papillary dermis (Fig. 2). Proliferation of endothelial cells and a perivascular dermal infiltrate containing plasma cells, which are histological hallmarks of syphilis (2), were not seen. Warthin-Starry stain of the skin biopsy specimen was negative for spirochetes. To provide a direct association between Treponema pallidum and the targetoid skin lesions, polymerase chain reaction (PCR) technology was used to detect treponemal genomic DNA in the skin lesions. The 47-kDa lipoprotein gene (GenBank accession no. M88769 and M27493) (3, 4) for T. pallidum was amplified using 40 cycles of 94oC for 1 min, 58oC for 1 min, and 72oC for 1 min. The final product was separated on 2% agarose gel, stained with ethidium bromide, and visualized by BioPrint/Bio1D (Vilber Lourmat, France). A 658 bp band of the PCR product specific for T. pallidum was present only in the skin biopsy specimens from this patient, as in the positive control, but not in the negative control (Fig. 3). Serological tests for syphilis showed venereal disease research laboratory test titres of 1:32, and the fluorescent treponemal antibody absorption test IgM and T. pallidum haemagglutination assay were reactive.

Extensive inflammation causes epithelial cell hyperplasia in the airways and Bcl-2-interacting killer (Bik) reduces epithelial cell and mucous cell hyperplasia without affecting resting cells to restore homeostasis. These observations suggest that Bik induces apoptosis in a cell cycle-specific manner, but the mechanisms are not understood. Mice were exposed to an allergen for 3, 14, or 30 days and Bik expression was induced in airway epithelia of transgenic mice. Bik reduced epithelial and mucous cell hyperplasia when mice were exposed to an allergen for 3 or 14 days, but not when exposure lasted for 30 days, and Ki67-positivity was reduced. In culture, Bik expression killed proliferating cells but not quiescent cells. To capture the stage of the cell cycle when Bik induces cell death, airway cells that express fluorescent ubiquitin cell cycle indicators were generated that fluoresce red or green during the G0/G1 and S/G2/M phases of the cells cycle, respectively. Regardless of the cell cycle stage, Bik expression eliminated green-fluorescent cells. Also, Bik, when tagged with a blue-fluorescent protein, was only detected in green cells. Bik phosphorylation mutants at threonine 33 or serine 35 demonstrated that phosphorylation activated Bik to induce death even in quiescent cells. Immunoprecipitation and proteomic approaches identified casein kinase IIα to be responsible for phosphorylating and activating Bik to kill cells in S/G2/M. Ascasein kinase 2 alpha (CKIIα) is expressed only during the G2/M phase, we conclude that Bik activation in airway epithelial cells selectively targets hyperplastic epithelial cells, while leaving resting airway cells unaffected.

Immunopathological study on the development of swine serum-induced bile duct lesions in BALB/c and DBA/2 mice

Cutaneous lupus erythematosus/lichen planus overlap syndrome

Sudden infant death due to dengue virus infection is very rare. An 8-month-old male infant was found unresponsive during a nap in his nursery school. We emphasize the usefulness of dengue viral antigens as a postmortem diagnostic technique to demonstrate the presence of virus in human tissue specimens by immunohistochemistry and Western blotting.

Early cutaneous Lyme disease, erythema migrans, may show different histopathologic patterns. The intent of this case series is to raise awareness of these findings to prevent misdiagnosis and keep this entity in the differential. Erythema migrans develops after a tick bite and subsequent infection with the spirochete, Borrelia burgdorferi. It most commonly manifests as a solitary, annular lesion with a bull's-eye appearance. Classic histopathologic findings include superficial and deep perivascular and interstitial lymphocytic infiltrates mixed with plasma cells and eosinophils. We identified and reviewed eight cases of early erythema migrans. Each patient had confirmed B. burgdorferi IgM seropositivity and IgG seronegativity. Histopathologic evaluation of these biopsies reveals a diversity of patterns. Seven of eight cases show sparse to mild perivascular and interstitial mixed infiltrate of variable amount of lymphocytes, eosinophils, neutrophils and plasma cells, with only one case showing a dense inflammatory infiltrate. Epidermal changes such as spongiosis and interface change are seen in some cases. Additionally, perineural lymphocytic infiltrate is seen in one case, periadnexal infiltrate in four cases and pigment incontinence in one case. Based on variable histopathologic findings, it is important to consider erythema migrans in the differential diagnosis for prompt diagnosis and treatment.

A 60‐year‐old obese man was referred to our department from the internal medicine unit. He had a 20‐year history of poorly controlled diabetes (no other cases in the family), and was admitted to hospital because of respiratory and consequent heart failure.Skin examination showed diffuse xerosis and a rough, sandpaper‐like appearance of the skin of the finger, of approximately 15 years’ duration, consisting of multiple, minute, hyperkeratotic papules grouped in a miniature “cobblestone” pattern on the dorsum of the distal phalanges (Fig. 1), more dense over the knuckles and the interphalangeal joints. No pruritus was present.Pebbly pattern of the skin on the dorsum of the second digitimageHe was a pensioner, who had been physically inactive for months previously, and this condition had occurred progressively in the absence of any known trauma. No other cutaneous manifestations were evident.Histologic examination was performed using hematoxylin and eosin staining of a biopsy specimen taken from the left second finger; it displayed a hyperorthokeratotic epidermis with enlarged dermal papillae, thickened and vertically oriented collagen bundles, few elastic fibers, and a mild perivascular inflammatory infiltrate (Fig. 2).Histologic view of a biopsy specimen of the skin of the finger: the epidermis is hyperkeratotic, the dermal papillae are enlarged and there are thickened vertical collagen bundles, elastic fibers, and a mild perivascular inflammatory infiltrate (hematoxylin and eosin stain; original magnification, ×100)image

Itchy erythroderma in a neoplastic patient—mind the mite!

Background: Cystic endometrial hyperplasia is a hormone-dependent disease induced by systemic increase in progesterone that can occur in several domestic species, such as the rabbit. This disease may be associated with sex steroid hormones, especially progesterone, and may be asymptomatic, and it is diagnosed using complementary imaging tests such as total abdominal ultrasound. However, surgical excisional biopsy with histopathological tissue analysis is the gold standard. This study reports a case of asymptomatic cystic endometrial hyperplasia in a female Miniature Lion Lop rabbit (Oryctolagus cuniculus domesticus) treated with therapeutic ovariohysterectomy.Case: A domestic, adult, female Miniature Lion Lop rabbit (Oryctolagus cuniculus domesticus), aged approximately 5 years and weighing 3.2 kg, was referred to specialized care to undergo ovariohysterectomy, an elective procedure. The tutor only reported the occurrence of a single episode of vulvar secretion more than 2 years ago, treated with antibiotics, with remission of clinical signs. In the intraoperative period after celiotomy, the uterine horn and uterine body showed a significant increase in volume, with abnormal color changes and tissue consistency; however, both changes were clinically asymptomatic. Subsequently, biopsy was performed during the ovariohysterectomy procedure. The excised uterus and ovaries were placed in 10% formalin and histopathologically analyzed. The macroscopic histopathological examination of the sectioned tissue revealed a slight amount of brownish fluid inside the uterine horns, in addition to multiple cystic areas in the uterine mucosa. Microscopic examination revealed marked hyperplasia of well-differentiated endometrial epithelial cells, occasionally forming cystic structures of different sizes. Moderate congestion, mild multifocal hemorrhage, and mild multifocal inflammatory infiltrate in the lamina comprising lymphocytes and plasma cells were also observed. Therefore, a diagnosis of cystic endometrial hyperplasia with mild lymphoplasmacytic endometritis was made. Observation of the patient was recommended without therapeutic indication.Discussion: Although the pathogenesis of cystic endometrial hyperplasia remains unknown, it is suggested that it is associated with the presence of sex steroids. Hence, this is a common disease in female rabbits, as they have non-seasonal polyestrous cycles and induced ovulation. Cystic endometrial hyperplasia may be asymptomatic or subclinical, without any significant clinical signs. Conversely, when associated with an infection such as pyometritis, the clinical signs include intermittent hematuria, anemia, lethargy, anorexia, and tenderness in the uterus on palpation. Although diagnosis can be made using total abdominal ultrasound and radiography, it can only be confirmed by the histopathological evaluation of the biopsied uterine tissue. Histopathological features of this disease include endometrial thickening with irregular glandular cystic elevations and hyperplasia of the pseudostratified cylindrical ciliated cells of the uterine glands. Furthermore, lymphoplasmacytic infiltrate is found in the uterine tissue, demonstrating an inflammatory reaction or bacterial infection concomitant with endometrial hyperplasia. In this case, the treatment of choice was therapeutic ovariohysterectomy, which is considered curative in this disease. Thus, ovariohysterectomy can resolve cystic endometrial hyperplasia in a domestic female Miniature Lion Lop rabbit.Keywords: surgery, ovariohysterectomy, rabbits, wildlife.Título: Hiperplasia endometrial cística em coelho-doméstico (Oryctolagus cuniculus domesticus)Descritores: cirurgia, ovariosalpingohisterectomia, coelhos, animais selvagens.

Two cases of radiation-induced skin injuries occurring after radiofrequency catheter ablation therapy for atrial fibrillation

Ultrastructural pathology in Hashimoto's thyroiditis

Experimental pestivirus infections in newborn goat kids

A case of secondary syphilis masquerading as cutaneous lymphoma

Cutaneous reactive angiomatosis is an unusual benign vascular disorder of the skin usually associated to systemic diseases. It is characterized by lobular or diffuse proliferation of small blood vessels with hyperplasia of endothelial cells, pericytes, and sometimes histiocytes. We report a 59-year-old man with asymptomatic erythematous-violaceous patches on back, palms, and elbows for 9 months. Laboratory examination revealed changes consistent with B-chronic lymphocytic leukemia. Cutaneous biopsy showed a predominantly lobular small blood vessel proliferation in dermis with pericytic hyperplasia and mild perivascular lymphoplasmacytic infiltrate. Spontaneous involution of lesions occurred after 6 months. A second biopsy performed at the beginning of clinical involution showed a less prominent vascular component with perivascular giant cells with coexpression of CD68 and CD 31. To our knowledge, this is the first case of cutaneous reactive angiomatosis with documented histopathological findings of clinical involution.