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Biomedical subjects

M M de Santi

Publications and source records attributed to M M de Santi.

At least 19 recordsLinked to original sources
PubMed2006

Routine assessment of hormonal receptor and her-2/neu status underscores the need for more therapeutic targets in Kenyan women with breast cancer.

OBJECTIVE: To report the expression of estrogen receptors, progesterone receptors and human epidermal growth factor receptor (Her-2/neu) in 158 Kenyan women with breast cancer and correlation with other prognostic indicators in this high-risk group. This study stressed the importance of routine assessment of the steroid receptors and Her-2/neu as a mode of therapeutic selection of patients for antihormonal or targeting monoclonal antibody (Herceptin) therapy, directed at the juxtamembrane domain of Her-2/neu protein in the developing countries such as Kenya. STUDY DESIGN: The study population consisted of 158 female patients with histologically confirmed breast carcinoma seen at the pathology department of The Nairobi Hospital. An immunohistochemical (IHC) study of ER, PR and Her-2/neu was conducted, followed by fluorescent in situ hybridization (FISH) validation for Her-2/neu gene amplification in cases initially scored as positive 2+ with IHC. Mastectomy samples registered at the pathology department of The Nairobi Hospital were used for this study. The study was approved by the institution's ethical review committee and informed consent obtainedfrom the concerned patients. RESULTS: In the studied cohort, positivity for both hormonal receptors and Her-2/neu was noted in 10 (6.33%) cases and negativity in 44 (27.85%) cases. Conversely, Her-2/neu negativity was noted in 32 (20.25%) cases with both steroid receptors positive and Her-2/neu positivity with both steroid receptors negative in 20 (12.66%) cases. Overall, no predictive factor was found in the Her-2/neu amplified 31/153 (20.26%) cases completely assessed with IHC and FISH. Grade III invasive ductal carcinomas, however, had a high prevalence of Her-2/neu overexpression. Association of both menopausal status (p = 0.044) and progesterone receptor status (p = 0.004) with high grade tumors were found to be statistically significant at 95% CI (p < 0.5). Consistent with other studies, Her-2/neu overexpression in this cohort was 20.26%. CONCLUSION: Her-2/neu positivity may activate ER expression through signaling kinases, and the combined target of mitogenic estrogen plus the monoclonal antibody therapy against Her-2/neu-overexpressing tumors expand chances of survival for patients in developing countries such as Kenya. The cost factor for these tests, selection for appropriate combined therapies and lack of awareness were noted as limiting factors for access to basic health care service and resulted in advanced tumor grade at time of patient presentation.

Adenocarcinoma↗
PubMed2004

Hypertelorism, ptosis, and myopia associated with drug-resistant epilepsy, mental delay, growth deficiency, ectodermal defects, and osteopenia.

We report a 30-year-old woman with hypertelorism, ptosis, and myopia associated with drug-resistant epilepsy (DRE, Lennox-Gastaut syndrome), mental delay, growth deficiency, ectodermal defects, and osteopenia. To the best of our knowledge, this patient has an unusual combination of symptoms not previously described, associated with severe central nervous system dysfunction. The ectodermal defects were present in a very intriguing form, were difficult to diagnose, and did not conform to any classification or previous description.

Adult↗
PubMed2003

18q-syndrome and ectodermal dysplasia syndrome: description of a child and his family.

The 18q- syndrome [MIM #601808] is a terminal deletion of the long arm of chromosome 18. The most common deletion extends from region q21 to qter. We report here a nine-year-old boy possessing a simple 18q- deletion who had abnormalities of the brain, skull, face, tooth, hair, bone, and skin, plus joint laxity, tongue palsy, subtle sensoneural deafness, mental and speech delay, attention deficit hyperactivity disorder (ADHD), tic, and restless legs syndromes. His karyotype was 46, XY, del (18)(q21.31-qter). The size of the deletion was approximately 45 cM. Most of these abnormalities were not explained by the 18q- deletion. The family pedigree suggested the presence of a subtle involvement of ectodermal and/or mesodermal structures. Karyotypes of the other family members were normal.

Abnormalities, Multiple↗
PubMed2003

Collagen phagocytosis by lung alveolar macrophages in animal models of emphysema.

Under steady state conditions the intracellular pathway is the major route of collagen catabolism in tissues characterised by rapid collagen turnover. In the lung, the collagen is subject to continuous remodelling and turnover however, the intracellular pathway of collagen degradation is unusual under physiological conditions. The current authors previously described crystalloid inclusions in alveolar macrophages of mice with genetic emphysema at the time of septal disruption. Using an immunogold technique these inclusions were identified as collagen-derived products and related to intracytoplasmic collagen degradation. To examine whether a different degree of protease burden in lung interstitium may influence the route of intracellular collagen degradation, collagen phagocytosis by alveolar macrophages was studied in various mouse models of emphysema at the time when emphysema develops. Evident collagen by-products in alveolar macrophages were observed in destructive processes characterising spontaneous models of emphysema either with negligible (blotchy mouse) or moderate (pallid mouse) elastase burden. On the other hand, intracellular collagen by-products were appreciated only in a few macrophages from tight-skin mice with high elastolytic burden and could not be observed in mice with a very severe burden after elastase instillation. In conclusion, the interstitial level of proteases burden can affect the way by which the collagen is cleared (intracellularly versus extracellularly).

Animals↗
PubMed2001

Static and ELF magnetic fields induce tumor growth inhibition and apoptosis.

The ability of static and extremely low frequency (ELF) Magnetic Fields (MF) to interfere with neoplastic cell function has been evaluated. In vitro experiments were carried out to study the role of MF characteristics (intensity, frequency, and modulation) on two transformed cell lines (WiDr human colon adenocarcinoma and MCF-7 human breast adenocarcinoma) and one nontransformed cell line (MRC-5 embryonal lung fibroblast). Increase in cell death morphologically consistent with apoptosis was reported exclusively in the two transformed cell lines. Cell-death induction was observed with MF of more than 1 mT. It was independent of the MF frequency and increased when modulated MF (static with a superimposition of ELF at 50 Hz) were used. Based on the in vitro results, four different MF exposure characteristics were selected and used to treat nude mice xenografted with WiDr cells. The treatment of nude mice bearing WiDr tumors subcutaneously. with daily exposure for 70 min to MF for 4 weeks caused significant tumor growth inhibition (up to 50%) by the end of the treatment when modulated MF were used for at least 60% of the whole treatment period and the time-averaged total MF intensity was higher than 3.59 mT. No toxic morphological changes induced by exposure were observed in renewing, slowly proliferating, or static normal cells. A discussion on the possible biophysical mechanism at the base of the observed biological results is also offered.

Adenocarcinoma↗
PubMed2001

Telomerase activity, Ki-67, cyclin D1 and A expression, and apoptosis in solitary fibrous tumors: additional features of a predictable course?

Solitary fibrous tumors (SFTs) are infrequent soft tissue neoplasms which are usually benign and surgically curable. However, their behavior is not always predictable, although several clinical and pathological criteria of malignancy have been established. In many cancers, including some soft tissue tumors, telomerase activity (TA) has been shown to be a new reliable pathological marker of malignancy. Overexpression of some cyclins is associated with higher degrees of malignancy and predictive of the clinical course. In this study, we evaluated TA, mitotic and apoptotic indices (MI, AI), and the expression of Ki-67, cyclins D1 and A in five typical and two clinicopathologically atypical SFTs, the latter two of which had also recurred. High TA was demonstrated in the two atypical cases, which also showed a higher labeling index to Ki-67, as well as higher cyclin D1 and A expression, and either none or very few apoptoses. We suggest that TA, Ki-67, cyclin expression, and AI be evaluated in SFTs as possible adjunctive pathological criteria of behavior.

Adult↗
PubMed1999

Macrophage migration inhibitory factor in the human prostate: identification and immunocytochemical localization.

BACKGROUND: Macrophage migration inhibitory factor (MIF) is a lymphokine originally identified for its capacity to inhibit the random migration of macrophages. Recent data have further extended knowledge of the physiological role of this protein, showing that MIF is produced by several human organs and tissues. The present study was intended to evaluate the expression and tissutal localization of MIF in the human prostate. METHODS: Prostate tissues were obtained from patients undergoing surgical adenomectomy for benign prostatic hyperplasia and were analyzed by Western blot, reverse transcriptase-polymerase chain reaction, immunohistochemistry, and immunoelectron microscopy. RESULTS. The presence of both MIF protein and mRNA was demonstrated in the prostate. Immunocytochemical studies localized MIF protein in the secretory luminal epithelial and basal layer cells. CONCLUSIONS: The present study demonstrated that the human prostate is a site of MIF synthesis. Macrophages populate the human prostate and represent an important mechanism of defense of integrity and functionality of the gland. It is speculated that MIF might play a role in preserving prostate physiological activity by maintaining its macrophage population.

Blotting, Western↗
PubMed1999

Ciliary motility at light microscopy: a screening technique for ciliary defects.

To verify whether or not ciliary motility can be reliably assessed by light microscopy alone, we examined the nasal brushings of 53 patients with suspected ciliary dyskinesia and 10 healthy controls. The results of light microscopy were compared with cilia ultrastructure assessed with electron microscopy. Ciliary motility was significantly related with cilia ultrastructure. However, eight cases of lung disease due to bronchiectasis of unknown origin had immotile cilia on light microscopy, but normal ciliary ultrastructure on electron microscopy. Instances of normal and abnormal ultrastructure were detected in one case with motile cilia. There was an 83% agreement between electron microscopy and light microscopy. Sensitivity and specificity of light microscopy were 92% and 80%, respectively. In conclusion, light microscopy evaluation of ciliary motility does not appear to be a reliable screening test for ciliary dyskinesia because it does not quantify ciliary beat activity, which is a criterion for deranged ciliary motion. A complete evaluation of ciliary ultrastructure together with in vivo, if applicable, or in vitro function test (namely, the analysis of ciliary beat frequencies and/or waveform) is required for a definite diagnosis of ciliary dyskinesia.

Adolescent↗
PubMed1995

Pallid mice with genetic emphysema. Neutrophil elastase burden and elastin loss occur without alteration in the bronchoalveolar lavage cell population.

BACKGROUND: According to a current hypothesis, pulmonary emphysema results from damage to the elastic fiber network caused by an imbalance within the lower respiratory tract between elastase(s) and protease inhibitors. This hypothesis is based largely on studies of persons with genetic deficiency of serum alpha 1-proteinase inhibitor. We recently reported a spontaneously occurring emphysema in the pallid mouse with an inherited deficiency of serum alpha 1-proteinase inhibitor. This animal reproduces important features of the human condition. We describe here the changes in alveolar elastolytic burden and in the bronchoalveolar lavage (BAL) cell population, which precede and accompany the development of emphysema in pallid mice. EXPERIMENTAL DESIGN: A possible correlation between the levels of lung elastase burden and the loss of lung elastin content was investigated in the period of development of emphysema in pallid mice. Changes in alveolar cells were investigated for specimens from BAL fluids and lung tissue by cytologic, histologic, and immunogold-electron microscopic methods. RESULTS: An immunogold-positive reaction for elastase was observed on elastin within the alveolar walls of pallid mice from 2 months onward. The average of gold particle density progressively increased with age, reaching high values at 12 and 16 months of age, the age at which parenchymal destruction was previously reported to occur. Lung elastin content had normal values at 2, 4, and 8 months of age. However, it was significantly lower at 12 and 16 months of age. The immunogold values of elastase burden correlated inversely with the decrease in lung elastin content. Total and differential cell counts from BAL fluids of pallid mice did not differ significantly at any time in life and were similar to age-matched controls. However, in pallid mice from 8 months of life onward, pulmonary macrophages contained characteristic intracytoplasmic crystalloid inclusions, which were electrondense and bounded by a single membrane. Using electron microscopy and an immunogold-labeling technique with anti-mouse I-III collagen IgG, these inclusions were identified as collagen-derived products. CONCLUSIONS: The data reported in this paper suggest that emphysematous lesions in pallid mice are associated with a progressive increase of elastase in alveolar intestitium and with loss of lung elastin. Surprisingly, the number of neutrophils in BAL fluids does not increase with the increase of lung elastolytic burden. However, intracytoplasmic crystalloid inclusions related to collagen degradation were observed in pulmonary macrophages of pallid mice at the time of septal disruption. The presence of similar structures in alveolar macrophages from mice or other animal species may be indicative of connective tissue breakdown or remodeling of tissue collagen.

Animals↗
PubMed1994

Cardiac collagen changes during the development of right ventricular hypertrophy in tight-skin mice with emphysema.

The tight-skin (Tsk) mouse is a genetic model of pulmonary emphysema. In this mouse, right ventricular hypertrophy (RVH) starts to develop at approximately 8 months of age, probably as a consequence of the emphysema. The aim of the present study was to investigate cardiac collagen synthesis, content, and types both before and during the development of RVH. Collagen synthesis, assessed by the [3H]proline incorporation method, was significantly increased in the right ventricle of 3-month-old Tsk mice. This was accompanied by a marked increase in right ventricle collagen content. Collagen typing showed no difference from controls. At 8 months of age collagen synthesis had returned to control values, right ventricular collagen content was elevated but held lower values than at 3 months, and collagen typing showed a prevalence of the more compliant type III. By 16 months of age, right ventricular collagen content had returned to control values and there was a shift in collagen types due to a relative increase of the more rigid type I. At 24 months of age right ventricular collagen content was increased again and collagen type I continued to predominate. These results suggest a dynamic role for collagen both before and during the development of RVH secondary to emphysema.

Animals↗
PubMed1993

Apoptotic index: discriminant feature for the differentiation of cutaneous diffuse malignant follicular center cell lymphomas from lymphoid hyperplasia.

Diffuse subtypes of cutaneous lymphoid hyperplasia (CLH; n = 18) and primary malignant follicular center cell lymphoma of the skin (FCCL, n = 11) were diagnosed by conventional histology, immunophenotyping on paraffin sections, and gene rearrangement analysis. We then counted on semithin, Azur A-stained sections of resin-re-embedded biopsy specimens the relative numbers of apoptotic bodies among all lymphoid cells (apoptotic index [AI]). The diagnostic value of AI was compared to that of mitotic indices (MI) and percentages of various cell types in the cutaneous infiltrate. Features of cellular infiltrates distinguishing to two groups of lesions, in the order of decreasing significance, were percent large lymphoid cells, percent medium-sized lymphoid cells (both higher in FCCL); percent small lymphoid cells, percent epithelioid/giant cells, and percent histiocytes/macrophages (all three higher in CLH). However, of all parameters tested, AI had the greatest discriminant value (median in FCCL 1.11%, in CLH 0.14%; p = 8 x 10(-6)). Two cases, diagnosed as CLH with all morphologic and immunologic methods used, showed B-cell monoclonality at the DNA level. Linear discriminant analysis determined the following order of distinctive power of variables: 1) AI; 2) MI; 3) percent small lymphoid cells; 4) percent medium-sized lymphoid cells; 5) percent large lymphoid cells; 6) percent epithelioid/giant cells; and 7) percent histiocytes/macrophages. The present study thus establishes AI as an important parameter in the differentiation of diffuse CLH from diffuse cutaneous FCCL.

Adult↗
PubMed1993

The pallid mouse. A model of genetic alpha 1-antitrypsin deficiency.

BACKGROUND: The current hypothesis of pulmonary emphysema is based on an alteration of the protease-antiprotease balance within the lower respiratory tract. This hypothesis derives largely from studies in emphysema patients with genetic deficiency in serum alpha 1-antitrypsin. In animals, naturally occurring deficiency in serum elastase inhibitory capacity associated with early development of emphysema has been reported in the tight-skin mouse. We describe here a mouse model of genetic deficiency of alpha 1-antitrypsin in which emphysema occurs late in life. EXPERIMENTAL DESIGN: A genetic deficiency in serum alpha 1-antitrypsin was investigated in pallid mice, a strain with spontaneous occurring emphysema. Additionally, the possible pathogenetic role of an elastase-anti-elastase imbalance in pallid mice was investigated using molecular biologic, biochemical, histologic, ultrastructural, and immunoelectron microscopic methods. RESULTS: Pallid mice have markedly low levels of serum alpha 1-antitrypsin associated with a severe deficiency in serum elastase inhibitory capacity. However, they have normal alpha 1-antitrypsin mRNA levels in the liver. At ultrastructural examination, disruption of alveolar septa is first seen at 8 months of age. At histologic examination, some patchy areas of air-space enlargement with destruction of alveolar septa are seen from 12 months of age onward. These histologic changes are paralleled by a decrease in lung elastin content. The development of the pulmonary lesions is preceded by an alveolar elastolytic burden detected by an immunogold technique. CONCLUSIONS: All these data suggest that the lung changes in pallid mice are the result of an elastolytic process due to a severe inborn deficiency of serum alpha 1-antitrypsin. This animal model reproduces important features of the human condition and may provide new insights into the pathogenesis of emphysema.

Animals↗
PubMed1992

Identification of elastase in human eosinophils: immunolocalization, isolation, and partial characterization.

Although an elastolytic activity in eosinophil-rich cell fractions from mice has been reported, this enzyme has not been purified and characterized as yet in any mammalian species. Eosinophilic elastase was isolated from human eosinophil fragments (cytosomes) obtained from normal and eosinophilic subjects. The enzyme was purified to apparent electrophoretic homogeneity by fast protein liquid chromatography. The enzyme shows the same physical properties of the major elastase isoenzyme of human neutrophils. In addition, like monocyte elastase, it reacts with a monoclonal antibody against human neutrophil elastase. The biochemical similarities observed between the above-mentioned enzymes and the immunolocalization findings strongly support the idea that human eosinophils and neutrophils contain the same enzyme activity. Eosinophils show immunoreactive material in both types of dense cytoplasmic granules. This observation supports the current hypothesis that the different types of eosinophilic granules represent successive morphological stages of maturation.

Cross Reactions↗
PubMed1992

Lung collagen synthesis and deposition in tight-skin mice with genetic emphysema.

The tight-skin (Tsk) mouse is a genetic model of pulmonary emphysema linked to a deficiency of serum antielastase. In this mouse occurrence of connective tissue abnormalities in various organs (systemic scleroderma) has been reported. The aim of the present work was to study lung collagen synthesis and deposition in Tsk mice. No differences in the collagen synthesis rate and morphology at the ultrastructural level were found in Tsk mice at birth. At 2 months of age, a marked increase in collagen was observed within the alveolar septa. At this time, an increased lung collagen synthesis, assessed by determining prolyl hydroxylase activity and incorporation of radiolabeled proline, was found in Tsk mice with respect to control mice. However, due to the ongoing parenchymal destruction, the values of total lung collagen at 6 and 12 months of age were only moderately but significantly increased with respect to those observed at 2 months. As a consequence, a progressive accumulation of lung collagen fibers was observed in the residual septa. The increase in collagen deposition was accompanied by a relative increase in type I collagen. Although the data in the literature would suggest a genetic cause for the lung collagen change in Tsk mice, the data presented here indicate that the change in lung collagen metabolism may be a part of a remodeling process taking place after lung destruction.

Animals↗