Advances in a rapidly emerging field of hair follicle stem cell research.

Human skin maintains the ability to regenerate during adulthood, as it constantly renews itself throughout adult life, and the hair follicle (HF) undergoes a perpetual cycle of growth and degeneration. The study of stem cells (SCs) in the epidermis and skin tissue engineering is a rapidly emerging field, where advances have been made in both basic and clinical research. Advances in basic science include the ability to assay SCs of the epidermis in vivo, identification of an independent interfollicular epidermal SC, and improved ability to analyze individual SCs divisions, as well as the recent hair organ regeneration via the bioengineered hair follicular unit transplantation (FUT) in mice. Advances in the clinic include recognition of the importance of SCs for wound repair and for gene therapy in inherited skin diseases, for example epidermolysis bullosa. The study of the HF stem cells (HFSCs) started by identification of epidermal SC in the HF bulge as quiescent "label retaining cells". The research of these cells emerged rapidly after the identification of bulge cell molecular markers, such as keratin 15 (K15) and CD34 in mice and CD200 in humans, which allowed the isolation and characterization of bulge cells from follicles. This paper provides an overview of the current knowledge on epidermal SCs in the HF describing their essential characteristics and the control of follicle SCs fate, their role in alopecia, as well as their use in tissue engineering.

[Erythroblasts in the peripheral blood of adult patient as an adverse prognostic sign--a case report]. / Eritroblasti u perifernoj krvi odraslog bolesnika kao nepovoljan prognosticki predznak--prikaz bolesnika.

Red blood cells (RBC) normally lose their nuclei before appearing in peripheral blood. After having undergone differentiation in bone marrow, blood cells must cross the blood-marrow barrier to enter the bloodstream. Erythroblasts, or nucleated red blood cells (NRBC), do not distort easily, so they cannot escape this barrier. Therefore, with the exception of the neonatal period, the presence of NRBCs in peripheral blood is always a pathologic finding. NRBCs may be found in the course of severe diseases and are associated with poor prognosis and higher mortality. The underlying pathophysiology of NRBCs in peripheral blood is not fully understood. It is hypothesized that their appearance could be provoked by either increased erythropoiesis or bone marrow micro-architectural damage mostly caused by inflammation and/or decreased tissue oxygenation. In addition, it is known that the mortality is higher in NRBC-positive patients as compared with NRBC-negative patients. Hereby we present a patient admitted to the hospital with the symptoms of cardiac failure and decompensated liver cirrhosis. The patient was already known to have liver cirrhosis of ethylic etiology, cardiac decompensation caused by hypertensive heart disease with permanent atrial fibrillation, chronic obstructive pulmonary disease, diabetes mellitus type 2, and cholelithiasis. During hospital stay, the patient developed acute pancreatitis and, soon after that, a stroke with left hemiparesis followed by cardiopulmonary arrest. Then he was transferred to the intensive care unit. Despite appropriate therapy, intensive care treatment and cardiopulmonary support, the patient's general state worsened, he developed multiple organ failure and died on day 10 of intensive care unit stay. Three days earlier, NRBCs were detected in peripheral blood and their concentration increased during the next two days before death. NRBCs are known to appear 1-3 weeks before death, but their appearance does not seem to be related to one particular cause of death. Still, detection of NRBCs is an independent risk of poor outcome, where the mortality increases with the increasing NRBC concentration. Detection of NRBCs in blood is a relatively early phenomenon prior to death, so screening for NRBCs may aid in the early identification of patients at high risk, and in making duly decision for NRBC-positive patients to obtain ongoing intensive care treatment.

[Pleural mesothelioma--case report]. / Mezoteliom pleure--prikaz bolesnika.

Pleural mesothelioma is a rare neoplasm with the incidence of 1-2 per million people. The incidence is higher in male population (10-30/million), whereas the incidence in female population is 2 per million. It occurs predominantly at older age (65+ years). The most common clinical manifestation of pleural mesothelioma is pleural effusion with dyspnea, which makes it a diagnostic problem since many cardiac diseases can have the same presentation. We report a case of pleural mesothelioma in an 80-year-old woman that presented with dyspnea and pleural effusion, which was at first considered as a sign of heart failure. Clinical presentation also included metabolic disorders and deep vein thrombosis, and the patient's epidemiologic history was negative, so diagnostic procedures including pleurocentesis were directed towards detection of the possible malignant disease. Cytologic analysis followed by biopsy pointed to the diagnosis of pleural mesothelioma. Persistent pleural effusions that do not coincide with cardiac disease, especially if accompanied by metabolic disorders and paraneoplastic syndromes, require additional diagnostic workup to identify the etiology of pleural effusion.

PERIORAL DERMATITIS: STILL A THERAPEUTIC CHALLENGE.

Perioral dermatitis is a common and often chronic dermatosis. In its classic form, it primarily affects women aged 15 to 45 years, but there are also variants including lupus-like and granulomatous perioral dermatitis, where granulomatous form is more common in childhood and affects mostly prepubescent boys. The etiopathogenesis of the disease remains unclear, but there is a frequent finding of prolonged use of topical products, especially corticosteroids, in the treatment of rosacea and seborrheic dermatitis, preceding the clinical manifestation of perioral dermatitis. Other causes important for the occurrence of the disease include various skin irritants, as well as other physical and hormonal factors, which all share the epidermal barrier dysfunction as an underlying main pathogenic factor. Clinical presentation of papulovesicular eruption in the perioral region with a typical narrow spared zone around the edge of the lips is characteristic. Therapeutic approach should be individually addressed, depending on the severity of clinical presentation and patient's age, with special attention to patient's education and continuous psychological support. In mild forms of perioral dermatitis, 'zero therapy' is the treatment of choice. In the initial treatment period, patients with steroid-induced perioral dermatitis should be closely followed up because the rebound phenomenon usually develops after cessation of previous topical treatment. In moderate disease, treatment includes topical metronidazole, erythromycin, and pimecrolimus, whereas in more severe cases the best validated choice is oral tetracycline in a subantimicrobial dose until complete remission is achieved. Systemic isotretinoin should be considered as a therapeutic option for patients refractory to all standard therapies.

Pulmonary tumorlets with surrounding fibrous tissue--suspected carcinoma: case report and review of the literature.

Pulmonary tumorlets are small, often multiple nodular proliferations of pulmonary neuroendocrine cells. They are common incidental findings in chronic inflammatory pulmonary diseases. They can also be found in normal lung parenchyma and as one part of the continuum known as diffuse idiopathic pulmonary neuroendocrine cell hyperplasia. In many cases, they are incidental histologic findings of no importance or clinical consequences, or they can be associated with a very slow progression of either obstructive or mixed obstructive/restrictive impairment with good prognosis. Only rarely, they metastasize to an adjacent lymph node or produce ectopic neuroendocrine products. When found during diagnostic examination, they represent a doubt to be a malignant tumor until proven otherwise, which is often impossible without biopsy or surgical removal of the adjacent lung lobe. Hereby, we present a patient with a persistent nodular lung structure after being treated for nonspecific symptoms, cough with non purulent sputum and pain among the scapulae, for a period of one month. He had otherwise normal clinical and laboratory findings, except for a mild mixed obstructive/restrictive pattern of impairment that was shown by lung spirometry. After 8 months, he underwent lobectomy of the medial lobe of the lung with partial lymphadenectomy, since the diagnostic methods applied could not define the nature of lung nodular infiltration. Histologic examination showed a few tumorlets surrounded by the fibrous tissue with a very dense lymphocyte infiltration. We present a review of the literature and emphasize the necessity to include tumorlets with adjacent fibrosis as part of the differential diagnosis of a solitary nodular lung structure.