A leg ulcer with hard, yellow projections

Gout is a multisystem disease that may present in different ways. We report an elderly man who presented with a large ulcer of the left leg with hard yellow projections evolving for one year. Analytical study revealed a normal uric acid level, but histopathology showed a focal basophilic acellular material compatible with a gouty tophus. This tophus represents the cardinal feature of advanced gout and may present several challenges to wound care professionals. In fact, the ulcer in our patient persisted after one-year follow-up. Our aim is to alert clinicians about a rare cutaneous presentation of gout that may be increasingly diagnosed.

Perianal purpuric plaques revealing an amyloid light-chain amyloidosis: case report and review of the literature

Systemic immunoglobulin light chain amyloidosis is the most common and severe type of amyloidosis. There is an abnormal fibrillary protein deposition in tissues that leads to progressive and irreversible organ dysfunction. The most commonly affected organs are kidney and heart. Although rare, cutaneous manifestations may be the first clinical sign of the disease and usually present as hemorrhagic lesions, such as purpura, petechiae, and ecchymosis. We present a 71-year-old man that presented to our department because of exuberant purpuric plaques in the anogenital area as the first manifestation of an amyloid light-chain (AL) amyloidosis. The multi-organ involvement in addition to rapid clinical deterioration precipitated the patient's death four months later.

COMMITTED EFFECTIVE DOSE DUE TO THE INTAKE OF 40K, 226Ra, 228Ra AND 228Th CONTAINED IN FOODS INCLUDED IN THE DIET OF THE RIO DE JANEIRO CITY POPULATION, BRAZIL

Annual effective dose due to the consumption of 40K, 226Ra, 228Ra and 228Th was estimated from high-resolution gamma spectrometry, food consumption data for the inhabitants of Rio de Janeiro City and dose coefficients published by the ICRP 119. A total of 31 samples of cereals, grains, vegetables, flours, liquid and perishables were analyzed. 40K was measured in all samples, and bean sample presented highest specific concentration 489.36 ± 23.70 Bq kg-1. The highest specific concentration for 226Ra, 228Ra and 228Th was measured in pumpkin (7.82 ± 1.09 Bq kg-1), carrot (30.18 ± 1.99 Bq kg-1) and beet (2.43 ± 0.48 Bq kg-1), respectively. The highest contribution to annual effective dose came from beans (556.3 μSv), potato (12.5 μSv), carrot (10.3 μSv), banana (4.7 μSv) and beet (3.3 μSv). It was observed that updates of daily food consumption values was the main reason for an up to 10-fold difference between the annual effective dose found in the present study and literature data.

Comparison of simulated and experimental values of self-absorption correction factors for a fast and credible adjust in efficiency curve of gamma spectroscopy

Self-absorption correction factors are fundamental in spectroscopy to correct the efficiency of the samples detection whose density is different from the radioactive standard. Mathematical simulations have been widespread as a tool to facilitate the procedure of correction factors calculation. In this paper, LabSOCS was used to calculate the self-absorption correction factor for some geometries and the values found were compared to those obtained in MCNP and experimental values. The percentage deviations found for the self-absorption correction factor calculated by LabSOCS were below 1.6% when compared to experimental values. Deviations were below 1.9% in the curve extrapolation of the experimental procedure found in literature. Results obtained show that the deviations increase proportionally to the difference between the density values of the radioactive standard and the sample. High percentage deviations were also noticed in simulations whose samples had high densities, complex geometries and low energy gamma-rays.

GLUT1, MCT1/4 and CD147 overexpression supports the metabolic reprogramming in papillary renal cell carcinoma

Papillary Renal Cell carcinoma (pRCC) is the second most common type of RCC, accounting for about 15% of all RCCs. Surgical excision is the main treatment option. Still, 10 - 15 % of clinically localized tumours will recur and/or develop metastasis early after surgery, and no reliable prognostic biomarkers are available to identify them. It is known that pRCC cells rely on high rates of aerobic glycolysis, characterized by the up-regulation of many proteins and enzymes related with the glycolytic pathway. However, a metabolic signature enabling the identification of advanced pRCC tumours remains to be discovered. The aim of this study was to characterize the metabolic phenotype of pRCCs (subtypes 1-pRCC1 and 2-pRCC2) by evaluating the expression pattern of the glucose transporters (GLUTs) 1 and 4 and the monocarboxylate transporters (MCTs) 1 and 4, as well as their chaperon CD147. We analysed the clinico-pathological data and the protein and mRNA expression of GLUT1, GLUT4 and MCT1, MCT4 and CD147 in tumours from Porto and TCGA series (http://cancergenome.nih.gov/), respectively. With the exception of GLUT4, plasma membrane expression of all proteins was frequently observed in pRCCs. GLUT1 and MCT1 membrane overexpression was significantly higher in pRCC2 and significantly associated with higher pN-stage and higher Fuhrman grade. Overexpression of GLUT1, MCT1/4 and CD147, supports the metabolic reprograming in pRCCs. MCT1 expression was associated with pRCC aggressiveness, regardless of the tumour histotype.

Melanocytic tumour in a black sheep never exposed to ultraviolet radiation

A slow growing skin tumour was identified on the head of a 6-year-old male Serra da Estrela black sheep. The animal had no previous history of exposure to ultraviolet radiation or illness. The tumour consisted of an irregular mass subdivided into two polypoid regions and there were small alternating pigmented and non-pigmented areas in the surrounding epidermis. Microscopical and immunohistochemical features were consistent with a melanocytic tumour of the melanocytoma type, without signs of vascular or perineural invasion. The tumour cells contained pigment stained by the Masson Fontana reaction, expressed S100 protein and vimentin and displayed a low proliferative rate (Ki67 labelling <1%). No metastases were found at the time of gross necropsy examination. Analyses of the homologous regions of the hot spot mutational exons of BRAF and NRAS (the genes that are most often mutated in human melanocytic tumours) did not reveal alterations, but there were silent polymorphic variations in these genes. No such variation was observed in the GNAQ gene sequence that is mutated in human melanocytomas.

Primary pleomorphic sarcoma of lung--11 year survival

Primary sarcomas of the lung are uncommon, potentially aggressive neoplasms that need to be distinguished from other malignant pulmonary tumors and whose biological behavior is as yet not fully understood. Primary undifferentiated pleomorphic sarcoma was diagnosed in the right lung of a 66 year-old man, who has survived over 11 years after treatment with endobronchial tumor debulking by laser therapy and radiotherapy.

Expression, mutation and copy number analysis of platelet-derived growth factor receptor A (PDGFRA) and its ligand PDGFA in gliomas

BACKGROUND

Malignant gliomas are the most prevalent type of primary brain tumours but the therapeutic armamentarium for these tumours is limited. Platelet-derived growth factor (PDGF) signalling has been shown to be a key regulator of glioma development. Clinical trials evaluating the efficacy of anti-PDGFRA therapies on gliomas are ongoing. In this study, we intended to analyse the expression of PDGFA and its receptor PDGFRA, as well as the underlying genetic (mutations and amplification) mechanisms driving their expression in a large series of human gliomas.

METHODS

PDGFA and PDGFRA expression was evaluated by immunohistochemistry in a series of 160 gliomas of distinct World Health Organization (WHO) malignancy grade. PDGFRA-activating gene mutations (exons 12, 18 and 23) were assessed in a subset of 86 cases by PCR-single-strand conformational polymorphism (PCR-SSCP), followed by direct sequencing. PDGFRA gene amplification analysis was performed in 57 cases by quantitative real-time PCR (QPCR) and further validated in a subset of cases by chromogenic in situ hybridisation (CISH) and microarray-based comparative genomic hybridisation (aCGH).

RESULTS

PDGFA and PDGFRA expression was found in 81.2% (130 out of 160) and 29.6% (48 out of 160) of gliomas, respectively. Its expression was significantly correlated with histological type of the tumours; however, no significant association between the expression of the ligand and its receptor was observed. The absence of PDGFA expression was significantly associated with the age of patients and with poor prognosis. Although PDGFRA gene-activating mutations were not found, PDGFRA gene amplification was observed in 21.1% (12 out of 57) of gliomas. No association was found between the presence of PDGFRA gene amplification and expression, excepting for grade II diffuse astrocytomas.

CONCLUSION

The concurrent expression of PDGFA and PDGFRA in different subtypes of gliomas, reinforce the recognised significance of this signalling pathway in gliomas. PDGFRA gene amplification rather than gene mutation may be the underlying genetic mechanism driving PDGFRA overexpression in a portion of gliomas. Taken together, our results could provide in the future a molecular basis for PDGFRA-targeted therapies in gliomas.

Epithelial-myoepithelial parotid carcinoma after kidney transplantation

The occurrence of a second malignant neoplasm (SMN) in patients who have been submitted to kidney transplantation is increasing and causes concern; parotid carcinoma is rarely reported after transplantation and may be related to long-term chemotherapy.Salivary gland carcinomas displaying exclusively myoepithelial differentiation-myoepithelial carcinomas (EMC) are rare, being less than 1% of all salivary gland tumours. EMC arises most commonly in the parotid gland and usually occurs in women. Their histopathologic features, immunohistochemical profile and clinical behaviour remain controversial.

Molecular alterations of KIT and PDGFRA in GISTs: evaluation of a Portuguese series

AIM

To assess KIT and PDGFRA mutations frequencies in a Portuguese series of gastrointestinal stromal tumours (GISTs).

METHODS

78 GISTs were evaluated for CD117 expression and screened for mutations in KIT (exons 9, 11, 13, 14 and 17) and PDGFRA (exons 12, 14 and 18) genes.

RESULTS

KIT activating mutations were identified in 44 (56%) of the 78 GISTs. Forty cases (91%) presented a mutation in KIT exon 11, and 4 (9%) in exon 9. One case showed a 4 bp deletion in intron 14. PDGFRA mutations were observed in 5 cases (6%): 2 (3%) in exon 12 and 3 (4%) in exon 18. Survival analysis was performed in 63 of the 78 GISTs. The presence of mutated KIT was significantly correlated with shorter survival of patients (p = 0.0460), and inversely associated with epithelioid histological type of GISTs (p = 0.0064).

CONCLUSIONS

Overall, the incidence of both KIT and PDGFRA mutations in these Portuguese series was 63%, being in agreement with other studies, mainly of Iberian populations. The great majority of mutations were located in KIT exon 11, statistically associated with worse prognosis and indicative of favourable response to imatinib-based therapy in this Portuguese series of GISTs.

TNM staging of midgut and hindgut (neuro) endocrine tumors: a consensus proposal including a grading system

Criteria for the staging and grading of neuroendocrine tumors (NETs) of midgut and hindgut origin were established at the second Consensus Conference in Frascati (Rome) organized by the European Neuroendocrine Tumor Society (ENETS). The proposed tumor-node-metastasis (TNM) classifications are based on the recently published ENETS Guidelines for the Diagnosis and Treatment of gastroenteropancreatic NETs and follow our previous proposal for foregut tumors. The new TNM classifications for NETs of the ileum, appendix, colon, and rectum, and the grading system were designed, discussed, and consensually approved by all conference participants. These proposals need to be validated and are meant to help clinicians in the stratification, treatment and follow-up of patients.

TNM staging of foregut (neuro)endocrine tumors: a consensus proposal including a grading system

The need for standards in the management of patients with endocrine tumors of the digestive system prompted the European Neuroendocrine Tumor Society (ENETS) to organize a first Consensus Conference, which was held in Frascati (Rome) and was based on the recently published ENETS guidelines on the diagnosis and treatment of digestive neuroendocrine tumors (NET). Here, we report the tumor–node–metastasis proposal for foregut NETs of the stomach, duodenum, and pancreas that was designed, discussed, and consensually approved at this conference. In addition, we report the proposal for a working formulation for the grading of digestive NETs based on mitotic count and Ki-67 index. This proposal, which needs to be validated, is meant to help clinicians in the stratification, treatment, and follow-up of patients.

Temporal giant cell reparative granuloma: a reappraisal of pathology and imaging features

We report a case of large temporal giant cell reparative granuloma in a 72-year-old man. MR imaging depicted a right temporal expansile multiloculated lesion, with hyper- and hypointense signal areas on T2-weighted images, heterogeneously enhancing after gadolinium administration. Cortical thinning and bone remodeling of the temporal squamous portion were better seen on CT. The patient underwent surgery, and the diagnosis was achieved by the correlation of imaging, histologic, and laboratory findings.

Spindle cell lipoma of the floor of the mouth. A case report

A sessile swelling in the floor of the mouth appeared three years ago in a 29-year old Caucasian female located laterally to the opening of the right duct of Wharton. The mass covered by normal looking mucosa exhibited slight growth since then. After excision, histological examination revealed the presence of a tumor formed by areas of mature adipose cells interspersed with extensions of tightly disposed fusiform fibroblasts immunoreactive for vimentin and CD-34. There were foci of concentric fibroblasts forming dense whorls. When large these conglomerates exhibited chondrocytes in the center. Mast-cells were not rare throughout the fibroblastic areas. No signs of malignancy occurred. These features led to the diagnosis of a spindle cell lipoma with chondrous metaplasia. The relative rarity of such a tumor in this location, especially in the chondrous variety, was considered worth of presentation, while the differential diagnosis with other intraoral tumors, namely mucoceles, dermoid cysts, mesenchymomas, fibromas and myxomas of the floor of the mouth, is discussed.

[Bullous pemphigoid in an infant]

Bullous pemphigoid is an acquired auto-immune blistering disease, which affects predominantly the elderly. It is rare in children and exceptional in infant. To our knowledge only ten cases were previously reported. We report a new case of a previously healthy six months old infant who presented with erythemato-vesico-bullous cutaneous lesions over a period of six days. Histology and immunofluorescence led to the diagnosis of bullous pemphigoid. Therapy with systemic and topic corticosteroids resulted in a good outcome.

Esophageal GIST: therapeutic implications of an uncommon presentation of a rare tumor

Gastrointestinal stromal tumors (GISTs) are rarely reported in the esophagus. The authors report a patient with an esophageal GIST, incidentally found after an echocardiogram. CT scan and endoscopic ultrasonography showed the tumor in the dependence of the muscularis propria of the esophageal wall. An Ivor-Lewis esophagectomy was performed. The tumor was well-circumscribed involving the submucosal and the muscular layers of the esophagus, measuring 13.5 x 8.5 x 7.6 cm, without involving the surgical margins. Histologically, the tumor consisted of spindle cells, with low mitotic index (2/50 HPF), that were immunoreactive for KIT (CD117) and CD34, consistent with GIST of high risk of aggressive behavior. No adjuvant therapy was given to the patient, who is alive and without evidence of disease 1 year after surgery. Since esophageal GISTs are rarely reported in the literature and usually have a poor prognosis, the diagnostic differentiation of these tumors from other more common mesenchymal neoplasms is essential, both for therapeutic and prognostic reasons.

Epithelioid hemangioendothelioma and multiple thoraco-lumbar lateral meningoceles: two rare pathological entities in a patient with NF-1

Epithelioid hemangioendothelioma (EHE) is a rare vascular soft-tissue tumour of intermediate malignancy. Neurofibromatosis type I (NF-1) is a genetic syndrome associated with soft tissue sarcoma and higher risk of developing neoplasia. Lateral meningoceles are uncommon entities, being mostly associated with NF-1. We report a case of a 31-year-old woman, with NF-1 and past history of right thalamic/peduncular astrocytoma WHO grade II, admitted to the Neurosurgery Department in December 2003 due to severe low back pain, irradiating to the left leg without a radicular pattern. Thoraco-lumbar magnetic resonance imaging (MRI) showed a large left posterior paravertebral expansive lesion, bilateral and multiple thoraco-lumbar lateral meningoceles and dural ectasias with scalloping of the vertebral bodies. Biopsy of the paravertebral mass lesion disclosed EHE. We present this case because of the novel association between NF-1 and EHE, and the unusual aggressiveness of the neoplasia. Additionally, we highlight the co-existence of bilateral and multiple lateral meningoceles.

Cardiorespiratory responses of the facultative air-breathing fish jeju, Hoplerythrinus unitaeniatus (Teleostei, Erythrinidae), exposed to graded ambient hypoxia

The jeju, Hoplerythrinus unitaeniatus, is equipped with a modified part of the swim bladder that allows aerial respiration. On this background, we have evaluated its respiratory and cardiovascular responses to aquatic hypoxia. Its aquatic O2 uptake (V(O2)) was maintained constant down to a critical P(O2) (P(cO2)) of 40 mm Hg, below which V(O2) declined linearly with further reductions of P(iO2). Just below P(cO2), the ventilatory tidal volume (V(T)) increased significantly along with gill ventilation (V(G)), while respiratory frequency changed little. Consequently, water convection requirement (V(G)/V(O2)) increased steeply. The same threshold applied to cardiovascular responses that included reflex bradycardia and elevated arterial blood pressure (P(a)). Aerial respiration was initiated at water P(O2) of 44 mm Hg and breathing episodes and time at the surface increased linearly with more severe hypoxia. At the lowest water P(O2) (20 mm Hg), the time spent at the surface accounted for 50% of total time. This response has a character of a temporary emergency behavior that may allow the animal to escape hypoxia.

A comparison of adrenergic stress responses in three tropical teleosts exposed to acute hypoxia

Experiments were performed to assess the afferent and efferent limbs of the hypoxia-mediated humoral adrenergic stress response in selected hypoxia-tolerant tropical fishes that routinely experience environmental O2depletion. Plasma catecholamine (Cat) levels and blood respiratory status were measured during acute aquatic hypoxia [water Po2(PwO2) = 10–60 mmHg] in three teleost species, the obligate water breathers Hoplias malabaricus (traira) and Piaractus mesopotamicus (pacu) and the facultative air breather Hoplerythrinus unitaeniatus (jeju). Traira displayed a significant increase in plasma Cat levels (from 1.3 ± 0.4 to 23.3 ± 15.1 nmol/l) at PwO2levels below 20 mmHg, whereas circulating Cat levels were unaltered in pacu at all levels of hypoxia. In jeju denied access to air, plasma Cat levels were increased markedly to a maximum mean value of 53.6 ± 19.1 nmol/l as PwO2was lowered below 40 mmHg. In traira and jeju, Cat release into the circulation occurred at abrupt thresholds corresponding to arterial Po2(PaO2) values of approximately 8.5–12.5 mmHg. A comparison of in vivo blood O2equilibration curves revealed low and similar P50values (i.e., PaO2at 50% Hb-O2saturation) among the three species (7.7–11.3 mmHg). Thus Cat release in traira and jeju occurred as blood O2concentration was reduced to approximately 50–60% of the normoxic value. Intravascular injections of nicotine (600 nmol/kg) elicited pronounced increases in plasma Cat levels in traira and jeju but not in pacu. Thus the lack of Cat release during hypoxia in pacu may reflect an inoperative or absent humoral adrenergic stress response in this species. When allowed access to air, jeju did not release Cats into the circulation at any level of aquatic hypoxia. The likeliest explanation for the absence of Cat release in these fish was that air breathing, initiated by aquatic hypoxia, prevented PaO2values from falling to the critical threshold required for Cat secretion. The ventilatory responses to hypoxia in each species were similar, consisting generally of increases in both frequency and amplitude. These responses were not synchronized with or influenced by plasma Cat levels. Thus the acute humoral adrenergic stress response does not appear to stimulate ventilation during acute hypoxia in these tropical species.

Malignant peripheral nerve sheath tumour-like primary cutaneous malignant melanoma

Malignant melanoma is known for its protean cytomorphological features, architectural patterns, and stromal changes, in addition to its ability to mimic various benign and malignant non-melanocytic tumours. Anecdotal cases of metastatic malignant melanoma simulating soft tissue sarcomas have been reported. Interestingly, this mimicry is more often seen in recurrent lesions and metastatic deposits. This report describes a case of a primary spindle cell cutaneous malignant melanoma with a prominent neural-like fascicular pattern and nuclear palisading, simulating a conventional malignant peripheral nerve sheath tumour (MPNST). Clinical, microscopic, and immunohistochemical features of the different entities included in the differential diagnosis of cutaneous spindle cell malignant tumours, such as MPNST, atypical fibroxanthoma, and spindle cell squamous cell carcinoma are discussed. Of note, the presence of an atypical epidermal or junctional component, cell pigmentation, and cell nesting, in addition to diffuse and strong reactivity for S-100 protein and other melanocytic markers, are helpful in the diagnosis of these troublesome lesions.

Chronic eosinophilic leukaemia presenting with erythroderma, mild eosinophilia and hyper-IgE: clinical, immunological and cytogenetic features and therapeutic approach. A case report

A 23-year-old, white male metallurgist presented with pruritic erythematous maculo-papules over the trunk and upper limbs and 6 months later developed erythroderma, eosinophilia and multi-organ dysfunction. A diagnosis of chronic eosinophilic leukaemia was made on the basis of myeloproliferative involvement of both peripheral blood and bone marrow, associated with eosinophilic differentiation and a t(5;12)(q33;p13) translocation. The initial therapeutic approach was interferon alfa-2b plus cytosine arabinoside, for 13 months, followed by hydroxyurea plus vincristine. There was improvement of skin lesions, disappearance of eosinophilia and decrease of serum immunoglobulin E, towards normal values.

Differential Ki67 and bcl-2 immunoexpression in solid-glandular and spindle cell components of biphasic synovial sarcoma: a double immunostaining assessment with cytokeratin and vimentin

AIMS

Synovial sarcoma is a malignant soft tissue of uncertain histogenesis that may show a biphasic (spindle and solid/glandular components) or a monophasic histological appearance. In previous studies, we demonstrated that the solid/glandular component possesses higher proliferation rates than the spindle cell component of biphasic synovial sarcomas and that the spindle cell component may exhibit a progressive transition from or to the solid-glandular component in biphasic synovial sarcoma. To evaluate this hypothesis further, we designed a novel approach to correlate immunoexpression of Ki67, bcl-2 and bax in the spindle cell and in the solid-glandular component of biphasic synovial sarcomas. We also performed a double-immunohistochemical assessment of the Ki67 proliferative indices and the immunoexpression of anti-apoptotic protein bcl-2 in neoplastic cells expressing either vimentin or cytokeratin.

METHODS AND RESULTS

Immunohistochemistry for vimentin (10 cases), bcl-2 (10 cases), Ki67(10 cases), cytokeratin (10 cases), and bax (eight cases), and double-immunostaining for vimentin/Ki67 (10 cases), vimentin/bcl-2 (nine cases), cytokeratin/Ki67 (10 cases), and cytokeratin/bcl-2 (10 cases) assays were performed in 10 cases of primary biphasic synovial sarcoma. Semiquantitative assessment was adopted for each case in both components. Statistical analysis was performed using Fisher's exact test or chi2 test. On conventional immunohistochemistry, the solid/glandular component revealed more expression of Ki67, bax and cytokeratin than the spindle cell component (P=0.0004, P=0.082, and P < 0.0001, respectively); on the other hand, the latter showed higher expression of bcl-2 and vimentin than the former (P=0.0281 and P=0.059, respectively). Double immunohistochemistry analysis revealed higher co-expression levels of cytokeratin/Ki67 and cytokeratin/bcl-2 than the spindle cell component (P=0.015 and P < 0.0001, respectively); conversely, the latter presented higher co-expression of vimentin/bcl-2 than the former (P=0.0007). All cases showed no more than 10% of cells coexpressing cytokeratin/bcl-2, cytokeratin/Ki67, and no case revealed cells coexpressing vimentin/Ki67.

CONCLUSION

Our findings indicate that in biphasic synovial sarcoma the acquisition of epithelial phenotype (solid/glandular component) is associated with a high expression of pro-apoptotic proteins and a high proliferative differentiation status, and conversely, mesenchymal phenotype (spindle cell component) is associated with a high expression of apoptosis-inhibitor bcl-2 and a low proliferative terminal-type differentiation status.

In situ corrosion control in industrial water systems

The main objective of this study was to evaluate the efficacy of a biocide and a corrosion inhibitor against the corrosion of a circulating pipe in a cooling tower. Isothiazolone was tested as the industrial biocide. The results showed that the biocide by itself or combined with a dispersant was not efficient to control corrosion in the industrial system. Corrosion rates of 0.324 mm/year were recorded in both the presence and absence of the biocide. Corrosion control was successfully accomplished by using a corrosion inhibitor. In the latter case the maximum corrosion rate of 0.024 mm/year were obtained.

Measuring beyond the microscope field of view using digital images in squamous cell carcinoma of the lip

OBJECTIVE

To study the impact of using digital images for measuring the size of the tumors, assisting with the prognostic evaluation of carcinomas of the oral mucosa.

STUDY DESIGN

The depth of invasion of 12 cases of squamous cell carcinoma of the lower lip was assessed through a microscope and through digital images. All measurements of depth of invasion were assessed in a direction orthogonal to the lip surface. First, assessment of depth of invasion was done at the microscope, using an eyepiece reticule with an engraved scale. Second, depth of invasion was assessed by digital images, using a program module developed to assist pathologists with linear measuring. When the depth of the tumor was larger than the field of view at the proper magnification, several images were taken to include the whole area of invasion. The images were finally mounted in a single image and the depth of invasion measured.

RESULTS

The results show positive and negative differences between assessments when assessing depths of < 2 mm. At greater depths (> or = 2 mm), the difference was always negative, showing that for deep invasion, measurements of longer distances were always performed on digital images.

CONCLUSION

Measurements with digital images beyond the field of view at proper magnification could sig nificantly alter the diagnostic and prognostic assessment made using the microscope.

[Neonatal apnea]

OBJECTIVE: To review medical literature related to apnea of prematurity. SOURCES: Extensive literature search and clinical practice-oriented concepts. SUMMARY OF THE FINDINGS: Apnea is one of the most common respiratory disorders in the neonatal period. Immaturity of the central nervous system is associated with instability of respiration. Therefore, apnea manifests itself in other systems, causing problems such as hypoglycemia, hypothermia, infection, or patent ductus arteriosus. Apnea may be central, obstructive or mixed depending on the presence of air flow through the upper airways. Diagnosis should involve careful observation by unit personnel and the monitoring of heart rate, respiratory frequency or arterial oxygen saturation. Initially, the treatment consists of xanthines (caffeine and aminophylline). If respiratory failure occurs, then continuous positive airway pressure (CPAP), and mechanical ventilation should be used. CONCLUSIONS: Preterm newborns are susceptible to respiratory problems, having apnea as a clinical manifestation of disorders in many organs and systems.

Over-expression of the INO2 regulatory gene alters regulation of an INO1-lacZ reporter gene but does not affect regulation of INO1 expression

The yeast INO2 gene encodes a transcriptional activator. Inositol and choline repress transcription of the INO2 gene, and its target genes. That is, INO2 transcription is auto-regulated. This observation prompted two separate investigations to determine if regulation of INO2 is required for regulation of its target genes. One study, using northern blot hybridization, showed that constitutive INO2 transcription did not affect regulation of the INO1 gene, while another study revealed that it severely dampened regulation of an INO1-lacZ gene. By repeating both assays from a single yeast strain we demonstrate that this disparity is due to the different reporter systems.

Expression of the INO2 regulatory gene of Saccharomyces cerevisiae is controlled by positive and negative promoter elements and an upstream open reading frame

The INO2 gene encodes a transcriptional activator of the phospholipid biosynthetic genes of Saccharomyces cerevisiae. Complete derepression of phospholipid biosynthetic gene expression in response to inositol/choline deprivation requires both INO2 and INO4. Ino2p dimerizes with Ino4p to bind the upstream activating sequence (UAS)INO element found in the promoters of the target genes. We have demonstrated previously that transcription from the INO2 promoter is autoregulated 12-fold in a manner identical to that of the target genes. Here, we show that this regulation occurs at the levels of transcription and translation. Transcription accounts for fourfold regulation, whereas translation accounts for an additional threefold regulation. Regulation of transcription requires a UAS(INO) element. Additional promoter elements include an upstream essential sequence (UES) located upstream of the UAS(INO) element and a negative regulatory element in the vicinity of the UAS(INO) element. Regulation of translation is dependent on an upstream open reading frame (uORF) in the INO2 leader. These data support the model that regulatory gene promoters may display unusual organizations and may be subject to multiple levels of regulation. We have shown previously that the UME6 gene positively regulates INO2 expression. Here, we limit the UME6-responsive region of the INO2 promoter to nucleotides -217 to -56.

A network of yeast basic helix-loop-helix interactions

The Ino4 protein belongs to the basic helix-loop-helix (bHLH) family of proteins. It is known to form a dimer with Ino2p, which regulates phospholipid biosynthetic genes. Mammalian bHLH proteins have been shown to form multiple dimer combinations. However, this flexibility in dimerization had not been documented for yeast bHLH proteins. Using the yeast two-hybrid assay and a biochemical assay we show that Ino4p dimerizes with the Pho4p, Rtg1p, Rtg3p and Sgc1p bHLH proteins. Screening a yeast cDNA library identified three additional proteins that interact with Ino4p: Bck2p, YLR422W and YNR064C. The interaction with Bck2p prompted us to examine if any of the Bck2p-associated functions affect expression of phospholipid biosynthetic genes. We found that hyperosmotic growth conditions altered the growth phase regulation of a phospholipid biosynthetic gene, CHO1. There are two recent reports of initial whole genome yeast two-hybrid interactions. Interestingly, one of these reports identified five proteins that interact with Ino4p: Ino2p, Hcs1p, Apl2p, YMR317W and YNL279W. Ino2p is the only protein in common with the data presented here. Our finding that Ino4p interacts with five bHLH proteins suggests that Ino4p is likely to be a central player in the coordination of multiple biological processes.

Combinatorial regulation of phospholipid biosynthetic gene expression by the UME6, SIN3 and RPD3 genes

The Ume6p-Sin3p-Rpd3p complex negatively regulates expression of genes containing a Ume6p binding site. However, these regulatory proteins also function independently to regulate gene expression both negatively and positively. The model system for this combinatorial regulation is the yeast phospholipid biosynthetic pathway. Sin3p negatively regulates the INO1, CHO1, CHO2 and OPI3 genes while Ume6p negatively regulates the INO1 gene and positively regulates the other genes. We have suggested that the positive regulation results from indirect effects on expression of the INO2 transcriptional activator gene. Here, we demonstrate that the effect of Ume6p on INO2 gene expression is also indirect. We also show that Rpd3p is a negative regulator of phospholipid biosynthetic gene expression. The ability of Ume6p, Sin3p and Rpd3p to differentially regulate expression of the phospholipid biosynthetic genes affects phospholipid composition. A sin3 mutant strain lacks detectable levels of phosphatidylethanolamine and elevated levels of phosphatidylcholine (PC) and a rpd3 mutant strain has reduced levels of PC. These alterations in membrane composition suggest that there may exist additional differences in regulation of phospholipid biosynthetic gene expression and that membrane compositions may be coordinated with other biological processes regulated by Ume6p, Sin3p and Rpd3p.

Effect of zeolite properties on ground-state and triplet-triplet absorption, prompt and oxygen induced delayed fluorescence of tetraphenylporphyrin at gas/solid interface

The ground-state and transient absorption, prompt and delayed fluorescence of tetraphenylporphyrin (TPP) adsorbed onto the external surface of different zeolites was monitored using diffuse-reflectance steady-state and laser flash photolysis. The delayed fluorescence (DF) of TPP detected in the presence of O2 is attributed to the energy transfer from 3TPP to 3O2 to form 1O2 and subsequent energy transfer from 1O2 to some other 3TPP within the organised molecular ensembles on the zeolite surface. The spectroscopic and kinetic parameters, namely the yield of DF (2-20% relative to prompt fluorescence), depend on the zeolite properties: the observed differences were correlated with the acid-base properties of the two zeolite series studied in this work (KA, NaA, CaA) and (NaA, NaX, NaY).

The promoter of the yeast INO4 regulatory gene: a model of the simplest yeast promoter

In Saccharomyces cerevisiae, the phospholipid biosynthetic genes are transcriptionally regulated in response to inositol and choline. This regulation requires the transcriptional activator proteins Ino4p and Ino2p, which form a heterodimer that binds to the UAS(INO) element. We have previously shown that the promoters of the INO4 and INO2 genes are among the weakest promoters characterized in yeast. Because little is known about the promoters of weakly expressed yeast genes, we report here the analysis of the constitutive INO4 promoter. Promoter deletion constructs scanning 1,000 bp upstream of the INO4 gene identified a small region (-58 to -46) that is absolutely required for expression. S1 nuclease mapping shows that this region contains the transcription start sites for the INO4 gene. An additional element (-114 to -86) modestly enhances INO4 promoter activity (fivefold). Thus, the region required for INO4 transcription is limited to 68 bp. These studies also found that INO4 gene expression is not autoregulated by Ino2p and Ino4p, despite the presence of a putative UAS(INO) element in the INO4 promoter. We further report that the INO4 steady-state transcript levels and Ino4p levels are regulated twofold in response to inositol and choline, suggesting a posttranscriptional mechanism of regulation.

SURVEY AND SUMMARY: Saccharomyces cerevisiae basic helix-loop-helix proteins regulate diverse biological processes

Basic helix-loop-helix (bHLH) proteins are among the most well studied and functionally important regulatory proteins in all eukaryotes. The HLH domain dictates dimerization to create homo- and heterodimers. Dimerization juxtaposes the basic regions of the two monomers to create a DNA interaction surface that recognizes the consensus sequence called the E-box, 5'-CANNTG-3'. Several bHLH proteins have been identified in the yeast Saccharomyces cerevisiae using traditional genetic methodologies. These proteins regulate diverse biological pathways. The completed sequence of the yeast genome, combined with novel methodologies allowing whole-genome expression studies, now offers a unique opportunity to study the function of these bHLH proteins. It is the purpose of this review to summarize the current knowledge of bHLH protein function in yeast.

Genetic profile of gliosarcomas

There are distinct genetic pathways leading to the glioblastoma, the most malignant astrocytic brain tumor. Primary (de novo) glioblastomas develop in older patients and are characterized by epidermal growth factor (EGF) receptor amplification/overexpression, p16 deletion, and PTEN mutations, whereas secondary glioblastomas that progressed from low-grade or anaplastic astrocytoma develop in younger patients and frequently contain p53 mutations. In this study, we assessed the genetic profile of gliosarcoma, a rare glioblastoma variant characterized by a biphasic tissue pattern with alternating areas displaying glial and mesenchymal differentiation. Single-strand conformation polymorphism followed by direct DNA sequencing revealed p53 mutations in five of 19 gliosarcomas (26%) and PTEN mutations in seven cases (37%). Homozygous p16 deletion was detected by differential polymerase chain reaction in seven (37%) gliosarcomas. The overall incidence of alterations in the Rb pathway (p16 deletion, CDK4 amplification, or loss of pRb immunoreactivity) was 53%, and these changes were mutually exclusive. Coamplification of CDK4 and MDM2 was detected in one gliosarcoma. None of the gliosarcomas showed amplification or overexpression of the EGF receptor. Thus gliosarcomas exhibit a genetic profile similar to that of primary (de novo) glioblastomas, except for the absence of EGFR amplification/overexpression. Identical PTEN mutations in the gliomatous and sarcomatous tumor components were found in two cases. Other biopsies contained p16 deletions, an identical p53 mutation, or coamplification of MDM2 and CDK4 in both tumor areas. This strongly supports the concept of a monoclonal origin of gliosarcomas and an evolution of the sarcomatous component due to aberrant mesenchymal differentiation in a highly malignant astrocytic neoplasm.

Expression of GUT1, which encodes glycerol kinase in Saccharomyces cerevisiae, is controlled by the positive regulators Adr1p, Ino2p and Ino4p and the negative regulator Opi1p in a carbon source-dependent fashion

In Saccharomyces cerevisiae glycerol utilization is mediated by two enzymes, glycerol kinase (Gut1p) and mitochondrial glycerol-3-phosphate dehydrogenase (Gut2p). The carbon source regulation of GUT1 was studied using promoter-reporter gene fusions. The promoter activity was lowest during growth on glucose and highest on the non-fermentable carbon sources, glycerol, ethanol, lactate, acetate and oleic acid. Mutational analysis of the GUT1 promoter region showed that two upstream activation sequences, UAS(INO) and UAS(ADR1), are responsible for approximately 90% of the expression during growth on glycerol. UAS(ADR1) is a presumed binding site for the zinc finger transcription factor Adr1p and UAS(INO) is a presumed binding site for the basic helix-loop-helix transcription factors Ino2p and Ino4p. In vitro experiments showed Adr1 and Ino2/Ino4 protein-dependent binding to UAS(ADR1) and UAS(INO). The negative regulator Opi1p mediates repression of the GUT1 promoter, whereas the effects of the glucose repressors Mig1p and Mig2p are minor. Together, the experiments show that GUT1 is carbon source regulated by different activation and repression systems.

[Joint effort to improve quality in a Brazilian pediatric public hospital through cross-infection control]

OBJECTIVES: To examine the role of the laboratory in nosocomial infection control from January 1993 to December 1996 in Centro Geral de Pediatria of Hospital Foundation of Minas Gerais state. METHODS: Follow -up of 101,139 patient-days (11,147 discharges + deaths + transfers) in the wards and intensive care unit by using the National Nosocomial Infection Surveillance (NNIS) system proposed by the Centers for Disease Control and Prevention (CDC- Atlanta). Prospective surveillance of nosocomial infections at all sites was performed according to the hospital - wide (since 1992) and intensive care unit (since 1996) NNIS components. The CDC definitions since 1988 and Brazilian Ministry of Health regulation number 930 since 1992 were used to diagnose the nosocomial infections. RESULTS: The five most frequent nosocomial pathogens (from a total of 139 isolates) were Klebsiella sp = 24.5%; S. aureus = 18%; P. aeruginosa = 13.7%; E. coli = 12.9%; S. epidermidis = 12.2%. The percentage of identification of pathogens isolated from nosocomial infection sites has increased from 6.2% in 1993 to 13.3% in 1995 and 28.2% in 1996 (p< 0.001) and so has the attempt to isolate the pathogens: 7.5% in 1993, 16.1% in 1995, 33.8% in 1996 (p< 0.001). The time interval taken for lab results (from specimen collected to microbiology result) has decreased from the average of ten days in 1993 to six days in 1996 (p = 0.001). CONCLUSIONS: The continuing education and improved communication among infection control personnel, pediatricians, surgeons and members of the laboratory have proven to play a key role in the epidemiology of nosocomial infections by defining their etiologies in the Centro Geral de Pediatria. A task force to determine the microbiology has been achieved by the understanding of all clinicians that it is important to treat their patients specifically. The NNIS method applied to Brazilian hospitals has shown its impact on the microbiology lab role in nosocomial infection control as well.

Intensified phototherapy using daylight fluorescent lamps

Jaundice is a common reason for therapeutic intervention in newborn infants and phototherapy is effective treatment if enough light energy is delivered to a skin surface area of sufficient size. Narrow spectrum blue light is superior to white light, but in developing countries fluorescent blue lamps often have to be imported and are much more expensive than white lamps. We developed a phototherapy unit in which seven daylight fluorescent tubes are placed immediately under the floor of a transparent plexiglass crib. The efficacy of this unit, delivering approximately 19 microW/cm2/nm, was compared with that of two conventional phototherapy units using overhead lamps placed 35 cm above the infants. One unit used daylight fluorescent tubes and delivered approximately 4 microW/cm2/nm, the other unit used special blue fluorescent tubes and delivered approximately 22 microW/cm2/nm. Fifty-one infants were included in the analyses, all of them breastfed on demand. Serum bilirubin levels were determined spectrophotometrically at 0, 12 and 24 h. The decrement in serum bilirubin concentrations was significantly greater in infants undergoing phototherapy with the new device or with special blue lamps compared to conventional overhead daylight lamps (p < 0.001 both at 12 and at 24 h). We conclude that highly efficient phototherapy may be delivered with daylight fluorescent lamps placed in very close proximity to the patient. Thus, lack of access to expensive imported special blue lamps does not preclude delivery of effective phototherapy in developing countries.

Surfactant replacement therapy: a multicentric trial comparing two dosage approaches

In this study the results of two different initial doses (Group A: 200 mg/kg--82 patients; Group B: 100 mg/kg--83 patients) of a porcine surfactant were compared in the treatment of neonatal respiratory distress syndrome. Main entry criteria were: birth weight between 700 and 2,000 grams, need of mechanical ventilation, FiO2 > or = 0.60 to obtain a PaO2 between 50 and 80 mmHg (PaO2/FiO2 < or = 133.3 mmHg) and less than 15 hours of postnatal age. Two further 100 mg/kg doses could be given in both groups at 12 hours interval if FiO2 was > 0.40. Birth weight (Group A: 1,231 +/- 281 g. and Group B: 1,324 +/- 355 g.), gestational age (Group A: 29.9 +/- 2.7 wk. and Group B: 30.6 +/- 2.6 wk.) and Apgar scores were similar in the two groups. Group A had a significantly higher mean PaO2/FiO2 ratio (p < 0.05) after 12 hours--178 (40-506) vs 133 (17-243) mmHg, before receiving a 2nd dose, after 24 hours--180 (17-431) vs 152 (39-360), and in the 3rd day--177 (40-333) vs 124 (24-249) and needed a lower FiO2 (p < 0.05) after 36 hours (0.47 +/- 0.20 vs 0.53 +/- 0.23) and on the 3rd day (0.51 +/- 0.23 vs 0.61 +/- 0.24). The mean peak inspiratory pressure was lower in Group A at 36 hours (17.5 +/- 4.5 vs 20.6 +/- 6.8) after the initial dose (p < 0.05). The time of exposure to high oxygen concentrations (FiO2 > or = 0.40) was lower in Group A--85 (3-643) vs 131 (3-672) hours; p < 0.05). Total amount of phospholipids given per patient was meanly 224 mg in Group A and 144 mg in Group B. Mortality was lower in group A but without significant difference (Group A: 17/82; Group B: 26/83). The analysis of the subgroup of babies with less than 1,500 gr. at birth showed a statistically significant difference in mortality (Group A: 15/70; Group B: 24/56; p < 0.02).

[Normal neonatal cerebral ultrasonography in preterm infants - Is it possible to calm down the parents?]

OBJECTIVE: To verify the predictive values of neonatal cerebral ultrasonography for motor and cognitive development of very low birth weight preterm babies after twelve months correct age. METHODS: The population studied was a cohort of preterm babies with birth weight less than 1,500g, who had been admitted in the Neonatal Intensive Care Unit of Instituto Fernandes Figueira, and were followed to 12-30 months corrected age for prematurity. A cerebral ultrasonography was performed before discharge. The results were classified as normal and abnormal (parenchymal hemorrhage, porencephaly, periventricular leucomalacia, ventricular dilatation). The babies were followed in the Follow-up Clinic and between 12-30 months correct age they underwent a neurological assessment with observation of the acquisition of motor milestones and submitted to Bayley Scales of Development. RESULTS: We studied 83 babies. Cerebral ultrasonography was normal in 68 babies (81.9%) and abnormal in 15 (18.8%). With a mean age of 21 months, 63 children (75.9%) had normal motor development and 20 (24.0%) had motor abnormalities. The cognitive development was normal in 68 children (81.9%). The negative predictive value of the cerebral ultrasonography for motor development was 85.3%, and for cognitive development, 86.8%. The positive predictive value of the cerebral ultrasonography for motor development was 66.7% and for cognitive development, 42.9%. CONCLUSIONS: The negative predictive values were greater than the positive predictive values in both areas of development. The probability for children with normal neonatal ultrasonography to have normal motor and cognitive development is greater than 85%.