Identification of Rickettsia rickettsii in formalin-fixed, paraffin-embedded tissues by immunofluorescence.
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With slight modification of a trypsin digestion technique, Rickettsia rickettsii were demonstrated specifically by immunofluorescence staining in Formalin-fixed, paraffin-embedded tissue sections from a human, rhesus monkey, and guinea pig with Rocky Mountain spotted fever and in infected membranes from a chicken embryo. Tissues were cut at 4 micron and, using geltain as a tissue adhesive, were hydrated in a routine manner. Sections were then digested in refrigerated 0.1% trypsin for 16 h, washed, and stained specifically for R. rickettsii by direct or indirect immunofluorescence. Rickettsial organisms were localized in affected vessels of the mammalian species and within the yolk sac epithelium of the chicken embryo. Specificity was confirmed by adsorbing antibody conjugates with R. rickettsii organisms. Trypsin digestion probably decreased tissue proteins which interfered with immunochemical attachment of antibody to the rickettsiae. The technique is valuable in that a diagnosis of Rocky Mountain spotted fever can be confirmed from Formalin-fixed tissues processed in a routine manner. (+info)
Ca2+ sensitization of smooth muscle contractility induced by ruthenium red.
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The effects of ruthenium red (RuR) on contractility were examined in skinned fibers of guinea pig smooth muscles, where sarcoplasmic reticulum function was destroyed by treatment with A-23187. Contractions of skinned fibers of the urinary bladder were enhanced by RuR in a concentration-dependent manner (EC50 = 60 microM at pCa 6.0). The magnitude of contraction at pCa 6.0 was increased to 320% of control by 100 microM RuR. Qualitatively, the same results were obtained in skinned fibers prepared from the ileal longitudinal smooth muscle layer and mesenteric artery. The maximal contraction induced by pCa 4.5 was not affected significantly by RuR. The enhanced contraction by RuR was not reversed by the addition of guanosine 5'-O-(2-thiodiphosphate) or a peptide inhibitor of protein kinase C [PKC-(19-31)]. The application of microcystin, a potent protein phosphatase inhibitor, induced a tonic contraction of skinned smooth muscle at low Ca2+ concentration ([Ca2+]; pCa > 8.0). RuR had a dual effect on the microcystin-induced contraction-to- enhancement ratio at low concentrations and suppression at high concentrations. The relaxation following the decrease in [Ca2+] from pCa 5.0 to >8.0 was significantly slowed down by an addition of RuR. Phosphorylation of the myosin light chain at pCa 6.3 was significantly increased by RuR in skinned fibers of the guinea pig ileum. These results indicate that RuR markedly increases the Ca2+ sensitivity of the contractile system, at least in part via inhibition of myosin light chain phosphatase. (+info)
A novel quantitative morphometry of germ cells for the histopathological evaluation of rat testicular toxicity.
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A view that 14 stages of rat spermatogenic cycle could be arranged into 4 groups, viz., conventional stages I-VI, VII-VIII, IX-XI and XII-XIV, according to the features of elongated spermatids was previously presented. A novel morphometry of seminiferous epithelia based on these 4 groups was also proposed. In the present study, utility of the proposed morphometry in the histopathological evaluations of testicular toxicities was monitored in comparison with the conventional one. After administrating adriamycin, ethylene glycol monomethyl ether or 1,3-dinitrobenzene to rats, the viability of their germ cells was estimated by the proposed morphometry and the conventional one employed stages II-III, V, VII, X and XII. In every case, the evaluating results of the proposed morphometry were similar to those of the conventional one. Thus, it was verified that the proposed morphometry was identical with the conventional one in respect of reliable detection of the testicular toxicities. In addition, in situ terminal dUTP nick end labeling indicated that death of spermatogonia, pachytene spermatocytes or round spermatids induced by the above 3 toxic compounds was exclusively apoptotic death. In conclusion, the proposed morphometry would be useful as a practical tool in the evaluation of testicular toxicities. (+info)
Infected total hip arthroplasty--the value of intraoperative histology.
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Intraoperative histology showed a sensitivity of 100% and a specificity of 98%. These results were better than those observed for the other tests evaluated. Our data provide evidence that intraoperative histology is useful tool in the diagnosis of infected total hip arthroplasty. (+info)
Diffuse large B-cell non-Hodgkin lymphomas: the clinical relevance of histological subclassification.
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In the REAL classification the diffuse large B-cell non-Hodgkin lymphomas (NHL) are grouped together, because subclassifications are considered to lack both reproducibility and clinical significance. Others, however, claim that patients with an immunoblastic NHL have a worse prognosis than patients with other types of diffuse large B-cell NHL. Therefore, we investigated the prognostic and clinical significance of histological subclassification of diffuse large B-cell NHL in a uniformly treated series of patients. For this retrospective study, all patients diagnosed as having an immunoblastic (IB) B-cell NHL by the Lymphoma Review Panel of the Comprehensive Cancer Center Amsterdam (CCCA) between 1984 and 1994, and treated according to the guidelines of the CCCA, were analysed. Patients with a centroblastic polymorphic subtype (CB-Poly) or centroblastic (CB) NHL by the Lymphoma Review Panel who were treated in the Netherlands Cancer Institute during the same period according to CCCA guidelines were used as reference groups. All patients' records were reviewed. Clinical parameters at presentation, kind of therapy and clinical outcome were recorded. All available histological slides were separately reviewed by two haemato-pathologists. One hundred and seventy-seven patients were included in the study: 36 patients (20.3%) with an IB NHL, 69 patients (39%) with a CB-Poly NHL and 72 patients (40.7%) with a CB NHL. The patients with an IB NHL tended to be older and presented more often with stage I or II and one extranodal site than patients with a CB and CB-Poly NHL. None of the subtypes showed a clear preference for localization in a particular site. The patients with IB or CB-Poly NHL showed a significantly worse prognosis than patients with CB NHL, with a 5-year overall survival for patients with CB NHL of 56.3% and for patients with IB or CB-Poly NHL 39.1% and 41.6% respectively. The 5-year disease free survival was 53.2% for the patients with CB, 32% for the patients with CB-Poly and 26.9% for the patients with IB NHL. A multivariate analysis showed that histological subtyping was of prognostic significance independent of the International Prognostic Index. This finding merits further exploration in prospective studies in order to judge the value of subclassification of large B-cell NHL as a guideline in therapy choice. (+info)
Pathobiological determinants of atherosclerosis in youth (PBDAY Study), 1986-96.
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This article is a summary of the 10-year multinational collaborative WHO/ISFC Study of Pathobiological Determinants of Atherosclerosis in Youth (PBDAY Study). Details are provided of the study design, relevant results, conclusions, and recommendations, as formulated at a consultation of the heads of PBDAY Reference Centres, held in Budapest, Hungary, in October 1996. The WHO/ISFC study provides unique information about the determinants of atherosclerosis and structural changes in the arteries, especially during their early stages, and their progression from early life in populations with vastly different lifestyles. The pilot study covered subjects aged 5-34 years, of both sexes, from 18 centres in 15 countries, while the main study covered 11 centres in 11 countries. Included were both developed and developing countries with different economic, sociocultural and nutritional patterns from five WHO regions. Collected was background epidemiological information, information about cases, and special studies of arteries using various morphometric methods and specialized techniques. Atherosclerotic lesions start to develop early in life independently of race, sex or geographical origin. The rate of fatty streak development is higher between 15 and 25 years of age, while raised lesions begin developing slowly during the second decade of life, progressing steadily during the third and more rapidly during the fourth. Fatty streaks are more prevalent among females and raised lesions among males. The prevalence and extent of raised lesions were greater in countries with a high prevalence of known risk factors and high mortality rates for cardiovascular diseases, coronary heart disease, and cerebrovascular diseases. (+info)
A proposed selective cell carcinogenesis in mammary tumors.
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The present study was done to ascertain whether a specific carcinogenic agent has a causal effect on the initial proliferation of only one cell type or whether it acts indiscriminately on all cells in the breast secretory unit. Enzymes histochemistry and electron microscopy were performed on DMBA-induced mammary tumors in female Sprague-Dawley rats and on virus-associated spontaneous mammary tumors in C3H/HEJ mice. The results showed that the chemical carcinogen DMBA affects initial myoepithelial cell proliferation, while virus-associated mammary carcinoma originated from ductular epithelial cell proliferation. To determine whether a specific tumor is composed of a single cell type, tumors were grown in tissue culture. The monolayer was fixed in the usual manner for electron microscopy while in Falcon tissue culture plates. The plates were dissolved in xylene and the monolayer was cut into small pieces and embedded in the plastic media. Electron microscopy performed on the tissue culture and the original tissue from the virus-induced tumors showed the presence of viruses in large numbers. It also suggested the differentiation of basal membrane to form basal lamina and apical plasma membrane into microvilli. This study strongly suggests the presence of selective cell carcinogenesis in the mammary gland. (+info)
Quantitative alterations of hyaluronan and dermatan sulfate in the hairless mouse dorsal skin exposed to chronic UV irradiation.
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The quantitative alterations of hyaluronan and dermatan sulfate in the upper dermis (fibrous tissue) and the lower dermis (adipose tissue) of the hairless mouse skin chronically exposed to the UV irradiation as solar-simulating irradiation (lambda(max) 352 nm, UV distribution: 300-310 nm, 0.9%; 310-320 nm, 2.0%; 320-420 nm, 97.1%) were evaluated. Hyaluronan and dermatan sulfate contents in each part of dermis were determined as follows: skin sections on a glass slide prepared by histological technique were processed into the upper dermis and the lower dermis with a small surgical knife, and treated with chondroitinase ABC and ACII in the presence of bacterial collagenase. The resulting unsaturated disaccharides were determined by HPLC method. By applying this method to the UV-irradiated hairless mouse skin, it was found that the chronic UV irradiation increased dermatan sulfate in the upper dermis, whereas an increase of hyaluronan content was not statistically significant. In the lower dermis, on the contrary, both hyaluronan and dermatan sulfate contents remarkably increased as compared with the control mice. Furthermore, the histological study showed the accumulation of the collagen fibers in the lower dermis of the UV-irradiated hairless mouse skin following the disappearance of adipocytes. These findings indicate that the increases of glycosaminoglycan contents in the UV-irradiated skin are related to the accumulation of the extracellular matrix components in the lower dermis. (+info)