Chromosomal characterization of Arvicanthis species (Rodentia, Murinae) from western and central Africa: implications for taxonomy

A chromosome study of unstriped grass rats of the genus Arvicanthis (Rodentia, Murinae) in western and central Africa is presented. The observations extend the data available to 242 specimens from 59 localities. All individuals karyotyped belong to four karyotypic forms, or cytotypes, earlier described as ANI-1, ANI-2, ANI-3, and ANI-4 and are presumed to correspond to four distinct species. In order to provide diagnostic characters for these western and one central African Arvicanthis species, we standardized the chromosomal data available and developed a G- and C-banded chromosome nomenclature that allows easy species identification. Each form is characterized by a distinct geographical distribution, roughly following the biogeographical domains of western Africa, although their precise limits remain to be assessed. The sole area of sympatry detected is the region of the inner delta of the Niger River, where both ANI-1 and ANI-3 can be found. It is proposed that the three western African species ANI-1, ANI-3, and ANI-4 be renamed as A. niloticus, A. ansorgei, and A. rufinus, respectively.

[The compromise of esophagus in HIV/AIDS diseases]

Esophageal disease is a common complication in patients infected with human immunodeficiency virus type-1 (HIV-1). Dysphagia, odynophagia and retrosternal pain are the most common symptons associated with the esophageal compromise. Esophageal candidiasis, the most frequent opportunistic infection, may occur in patients with long-standing infection or may be a manifestation of the seroconversion. Cytomegalovirus and Herpes simplex virus are more likely to produce esophageal ulcers or erosions. HIV itself may be responsible for ulcerative esophagitis. Neoplasms as Kaposi's sarcoma, are an infrequent cause of symptomatic disease. Barium esophagography and specially upper endoscopy are the most commonly employed diagnostic modalities for the evaluation of symptomatic patients. Endoscopy may be warranted to make a rapid diagnosis such that specific therapy will not be delayed. The use of a combination of histologic, cytologic, mycologic and virologic studies is necessary to provide an etiologic diagnosis of these lesions.

[Primary esophageal lymphoma in a patient with AIDS]

Primary esophageal lymphomas are extremely rare. We report a primary esophageal T cell lymphoma of a diffuse large cell phenotype B in a patient with AIDS. Also we reviewed other published cases. The diagnosis of this complication should be considered in HIV seropositive patients with progressive displagia and endoscopic findings of masses, polyps or ulcerations and, specially in those unresponsive to antifungal or antiviral therapy. Biopsy and histopathologic studies are needed to confirm the diagnosis.

[Disseminated infection due to strongyloides stercoralis in AIDS patients. A report of 2 cases]

Strongyloides stercoralis is an intestinal nematode that infects humans worldwide. Infected patients with severe involvement of cellular immunity may develop a syndrome characterized by the dissemination of larvae throughout the body. Extraintestinal strongyloidiasis has been infrequently reported and despite the prevalence of the helminth in tropical and developing countries there are few cases reported in AIDS patients. Most patients with disseminated strongyloidiasis present with fever, cough, diarrhea and shortness of breath. Chest radiographs usually show diffuse infiltrates. The diagnosis has been made by finding the helminth in respiratory secretions or stool. Enteric organisms like Escherichia coli can often be isolated in the blood or cerebrospinal fluid. We report two cases of disseminated strongyloidiasis in AIDS patients, in which stercoralis larvae were detected in sputum and stool samples.

[Rhabdomyolysis as a complication of Parkinson's disease]

BACKGROUND

Rhabdomyolysis is known as one of the possible causes of acute renal failure and can be triggered by different situations. In recent years, Parkinson's disease emerged as a condition that can be complicated by the development of rhabdomyolysis and consequently, in some cases, of acute renal failure. We report two cases of rhabdomyolysis, one of which complicated by an oligo-anuric renal failure, which occurred in patients affected by Parkinson's disease and admitted to our Division.

METHODS AND RESULTS

The first case occurred in a 90-year-old Parkinsonian woman, under treatment with Levodopa-Benserazide and Bornaprine. She developed rhabdomyolysis (CPK 1746 U/L with MB isoenzyme 3.5 ng/ml, LDH 610 U/L, GOT 78 U/L) after she had been found lying on the floor, in a state of mental confusion, after 24 hours in which her relatives had not heard from her. During the first two days of hospitalization, the patient also had a fever (axillary temperature between 37 degrees C and 38 degrees C), accompanied by mild leukocytosis (WBC 13000/mm3) on entrance. The second case occurred in a 78-year-old Parkinsonian woman, under treatment with Levodopa-Carbidopa, Levodopa-Benserazide and Pramipexol. She developed a severe rhabdomyolysis (CPK 34800 U/L with MB isoenzyme 771 ng/ml, LDH 2133 U/L, GOT 785 U/L) complicated by acute renal failure with anuria, after two days characterized by several episodes of vomit and diarrhea. In the following days we learned that in the last 20 days before admission to hospital the patient had increased the dose of her anti-Parkinson therapy and was almost always disturbed by severe choreiform and dystonic movements.

CONCLUSIONS

Regarding the first case, the clinical conditions in which the patient was found, the simultaneous presence of fever and leukocytosis and the absence of any reasonable explanation for a hypothetical fall to the floor induced us to think that this was a case of rhabdomyolysis in the context of an akinetic hyperthermic crisis. This is a syndrome that can develop in Parkinsonian patients after discontinuance or simply reduction of therapy with dopaminergic agents and is characterized also by rhabdomyolysis. The fact that the patient was living alone would confirm this hypothesis. On the other hand, the second case of rhabdomyolysis must probably be related to the severe choreiform and dystonic movements that the patient developed in the days just prior to admission. These movements were surely caused by the increase of the substitutive therapy with Levodopa by the patient herself. In conclusion, these two clinical cases, together with others previously reported by other Authors, show how the circumstances leading to the development of acute episodes of rhabdomyolysis in Parkinson's disease can be different and, at the same time, how these circumstances are always somehow related to the treatment of the basic disease with dopaminergic drugs.

[Malaria in Grosseto Maremma: a social disease]

Several kind of sources testify that, since XIVth century, people living in Grosseto during the summer moved to healthy towns located in neighbouring hills. Starting from the XVIth century malaria became a true scourge for people living in Maremma (especially day labourers and soldiers), and local "signorie" planned some attempts to improve their condition. However, only after the unification of Italy, and the discovery of the role of anopheles in transmitting the etiological agent, the fight against malaria acquired a scientific basis. At the end of the last century, the epidemiology of malaria in the Maremma Grossetana was studied by outstanding scientists (Koch, Grassi and Gosio among others). The present essay explores the archival sources concerning the history of malaria in the Maremma Grossetana from the beginning of "estataura" to antimalarial campaigns carried out during the first three decades of the XXth Century.

TNF-alpha, PDGF, and TGF-beta(1) expression by primary mouse bronchiolar-alveolar epithelial and mesenchymal cells: tnf-alpha induces TGF-beta(1)

The bronchiolar-alveolar epithelium (BAE) is a primary target site for inhaled agents that cause lung injury. These cells, consequently, release a broad range of mediators that influence other cell populations, including interstitial lung fibroblasts that are central to the development of interstitial pulmonary fibrosis (IPF). A number of peptide growth factors (GF) have been postulated to be essential in the pathogenesis of IPF. We demonstrate here that primary populations of mouse BAE and mesenchymal cells, maintained in culture, synthesize four potent GF. These are platelet-derived growth factor isoforms (PDGF) A and B, transforming growth factor beta-1 (TGF-beta(1)), and tumor necrosis factor alpha (TNF-alpha). A mouse lung epithelial cell isolation technique pioneered in this laboratory has been used to purify the BAE cells to greater than 85% (80 +/- 5.6% alveolar type II and 9 +/- 2.3% Clara cells) in culture. Northern analysis, RNase protection assay, and immunocytochemistry (ICC) were used to establish mRNA and protein expression of the GF over time in the cultured BAE and mesenchymal cells. We show for the first time in these primary mouse lung cells that treatment of both cell types with TNF-alpha upregulates expression of TGF-beta(1). The four GF are produced by both epithelial and mesenchymal cells but with different temporal patterns. TGF-beta(1) is expressed constitutively by BAE and mesenchymal cells, whereas TNF-alpha expression wanes over time. The findings by ICC were consistent with levels of mRNA expression in both cell types. As genetically defined and altered mouse strains are becoming increasingly valuable for modeling lung disease, studying the gene expression patterns of target cells from these animals in vitro would be useful in sorting out the complex responses by individual cell types of the lung and the interactions among the multitude of mediators that are released during lung cell injury.

Endocytosis and signaling cascades: a close encounter

Internalization of receptors and other cell surface components is well known to occur via clathrin-mediated endocytosis, although other less well characterized pathways are also involved. Internalized receptors are then delivered to early endosomes, where they are sorted to be recycled back to the plasma membrane for reutilization or transported to late endosomes/lysosomes for degradation. Endocytosis has long been considered as a constitutive, housekeeping function of animal cells that occurs independently of the cellular environment in contrast to regulated secretion. Here, we will discuss recent studies that are uncovering the existence of cross-talk between signaling molecules and components of the transport machinery, indicating that endocytosis can be modulated by signaling pathways.

Molecular phylogeny of Myomys/Stenocephalemys complex and its relationships with related African genera

Partial 16S rRNA mitochondrial gene sequences were used to infer the phylogenetic relationships among Stenocephalemys albocaudata, S. griseicauda and Myomys albipes, three closely related Ethiopian endemic murines and a selection of related species (Myomys daltoni, Praomys delectorum, Mastomys natalensis, Hylomyscus kaimosae, and Colomys goslingi) from other African regions. The obtained phylogeny confirms the close relationship between M. albipes and the two Stenocephalemys species, but it also suggests that both the genera Myomys and Stenocephalemys are paraphyletic, as M. albipes is closer to Stenocephalemys than to M. daltoni and S. griseicauda is more closely related to M. albipes than to S. albocaudata. These data, if confirmed, would argue that M. albipes should be renamed S. albipes. In conclusion, our study suggests that morphological similarity is not always a reliable measure for close genetic relationship in murines. Morphological similarity among species that evolved under similar ecological conditions can be the result of convergent evolution rather than a consequence of recent common ancestry.

[HIV infected macrophages isolated from HIV+ patients with undetectable viral load undergoing combined antiretroviral treatment]

A new method of culture of peripheral blood leukocytes (PBMC) from HIV+ patients, in the absence of exogenous stimuli (allogeneic cells or cytokines) (PBMC w/s) was used for the detection of persistent viral infection in HIV patients who had undergone successful highly active antiretroviral therapy (HAART) lowering their viral burden to undetectable levels (< 50 RNA copies/ml). Infected cells were always of the monocyte/macrophage lineage (M). No infection could be detected in these patients using the classical system (co-culture with HIV-CMP activated with PHA and IL-2). Differences in the class of target cells (higher proportion of proliferating M and CCR5 expressing cells in the PBMC w/s system than in PBMC-PHA cultures) may determine the relative sensitivity of each technique to achieve successful isolation of HIV from different patients.

[Cavum lymphoma in a hemophilic patient with AIDS]

Intermediate and highly malignant non-Hodgkin and primary central nervous system lymphomas are marker diseases for AIDS. Cavum and oropharynx involvement by these tumors is uncommon. Although there are few cases reported in the literature, these may be primary localizations of the tumor. We present a hemophilic HIV+ patient with non-Hodgkin lymphoma of the cavum. The histologic diagnosis was high-grade, pleomorphic, centroblastic lymphoma. The patient was treated with chemotherapy plus intrathecal chemotherapy and highly active antiretroviral therapy (HAART). His evolution has been excellent. One year after diagnosis, the patient is asymptomatic with no evidence of residual tumor, and responding well to HAART.

The stress-induced MAP kinase p38 regulates endocytic trafficking via the GDI:Rab5 complex

Early endocytic membrane traffic is regulated by the small GTPase Rab5, which cycles between GTP- and GDP-bound states as well as between membrane and cytosol. The latter cycle depends on GDI, which functions as a Rab vehicle in the aqueous environment of the cytosol. Here, we report that formation of the GDI:Rab5 complex is stimulated by a cytosolic factor that we purified and then identified as p38 MAPK. We find that p38 regulates GDI in the cytosolic cycle of Rab5 and modulates endocytosis in vivo. Our observations reveal the existence of a cross-talk between endocytosis and the p38-dependent stress response, thus providing molecular evidence that endocytosis can be regulated by the environment.

[Eye involvement in AIDS-related Kaposi sarcoma]

BACKGROUND

The study evaluates the incidence of ocular compromise in the Kaposi's sarcoma associated with AIDS.

METHODS

We revised the clinical histories of HIV seropositives patients seen in the ophthalmology department from January, 1994 to December, 1998. All patients were examined by direct visually and dilated fundus examination with the use of either a direct or an indirect ophthalmoscope.

RESULTS

In 6,552 patients, ocular Kaposi's sarcoma was diagnosed in 17 (0.25%), predominantly in male sex (88.23%). The lesions predominated in eyelids, and the inferior has been the most affected. In only one female, the ocular compromise was the first neoplastic manifestation.

CONCLUSIONS

The ocular compromise in the Kaposi's sarcoma is an alternative to be considered in AIDS patients with previous or simultaneous cutaneous or visceral involvement. Due to the few clinical signs of these lesions, a thorough ocular study is recommended in these patients.

Use of two-block partial least-squares to study covariation in shape

The relatively new two-block partial least-squares method for analyzing the covariance between two sets of variables is described and contrasted with the well-known method of canonical correlation analysis. Their statistical properties, type of answers, and visualization techniques are discussed. Examples are given to show its usefulness in comparing two sets of variables--especially when one or both of the sets of variables are shape variables from a geometric morphometric study.