Conventional Histopathological Techniques Research Articles

Decrease of Apoptosis Rate in Patients with Renal Transplantation Treated with Mycophenolate Mofetil

Background/Aims: Mycophenolate mofetil (MMF) is a powerful immunosuppressant that inhibits the proliferation of lymphocytes by blocking the enzyme inosine monophosphate dehydrogenase. MMF prevents acute graft rejection in organ transplants. The aim of this investigation is to study whether MMF has any influence on apoptosis and proliferation rates of cells other than lymphocytes. Methods: We conducted a retrospective study of renal allograft biopsies taken during the 1st week after transplantation in 25 patients receiving triple therapy with prednisone, ciclosporin and azathioprine 75 mg/day and in 25 patients treated with MMF at a dose of 2 g/day instead of azathioprine, in order to investigate the differences in the proliferation and apoptosis rates of the glomerular, tubular, interstitial and endothelial cells of the kidney. Twelve normal kidneys were used as controls. Conventional histopathological techniques were applied as usual for pathological diagnosis. Proliferative activity was assessed by use of MIB-1 antibody. Sections of formalin-fixed, paraffin-embedded tissue blocks were stained for the presence of apoptotic cells by TUNEL assay. Evaluation of proliferative or apoptotic rates was made by counting the number of positive cells in 10 glomeruli and in 10 transversely cut tubuli in each biopsy. The positive cells in the interstitium were counted in ten high-power fields. Positive cells in the endothelium were scored semiquantitatively from 0 to 3: 0 = none, 1 = isolated cells, 2 = small groups of cells, 3 = most endothelial cells. Mann-Whitney U and chi-square tests were used for intergroup comparisons. Results: All biopsies were normal or had borderline (Banff classification) acute rejection. MIB–1 rates were similar in both groups, without statistical differences (p > 0.05) between them. Significantly lower apoptotic rates were found in the group treated with MMF in tubular epithelium (23.41 ± 8.86 vs. 57.4 ± 13.42; p = 0.021), in glomerular (1.25 ± 0.78 vs. 5.3 ± 1.66; p = 0.027), and interstitial cells (1.58 ± 0.6 vs. 5.8 ± 1.54; p = 0.043). Apoptosis in endothelial cells (p > 0.05) was similar in both groups. Conclusion: We conclude that treatment with MMF of kidney transplant patients does not affect the proliferative rate of cells of the allograft, but decreases the number of apoptotic cells in tubular epithelium.

Cutaneous melanoma-associated paraneoplastic retinopathy: histopathologic observations

PURPOSE: To describe the retinal histopathology of paraneoplastic retinopathy associated with cutaneous melanoma. METHODS: A 59-year-old man had visual loss attributable to paraneoplastic retinopathy and died of metastatic cutaneous melanoma. His eyes were studied by conventional histopathologic techniques. RESULTS: Histopathologic examination of both eyes disclosed a marked reduction in the density of bipolar neurons in the inner nuclear layer; photoreceptor cell neurons in the outer nuclear layer were normal. Ganglion cells were present, although many showed evidence of transsynaptic atrophy. CONCLUSION: The histopathologic changes observed are consistent with clinical, immunologic, and electrophysiologic data that implicate the bipolar cell as the major site of the paraneoplastic process in cutaneous melanoma-associated retinopathy.

Predictors of subclinical nodal involvement in clinical stages I and II non-small cell lung cancer: implications in the inoperable and three-dimensional dose-escalation settings

Purpose: When mediastinal lymph nodes are clinically uninvolved in the setting of inoperable non-small cell lung cancer, whether conventional radiation techniques or three-dimensional dose-escalation techniques are used, the benefit of elective nodal irradiation is unclear. Inclusion of the clinically negative mediastinum in the radiation portals increases the risk of lung toxicity and limits the ability to escalate dose. This analysis represents an attempt to use clinical characteristics to estimate the risk of subclinical nodal involvement, which may help determine which patients are most likely to benefit from elective nodal irradiation.Methods: From 1987 to 1990, 346 patients undergoing complete resection of non-small cell lung cancer underwent a preoperative computed tomographic scan revealing no clinical evidence of N2/N3 involvement. Multivariate regression and regression tree analyses attempted to define which patients were at highest risk for subclinical mediastinal involvement (N2) and which patients were at highest risk for subclinical N1 and/or N2 involvement (N1/N2). Immunohistochemical data suggest that the conventional histopathologic techniques used during this study somewhat underestimate the true degree of lymph node involvement; therefore, a third end point was also evaluated: N1 involvement and/or N2 involvement and/or local-regional recurrence (N1/N2/LRR).Results: Regression analyses revealed that the following factors were independently associated with a high risk of more advanced disease: positive preoperative bronchoscopy (N2, p = 0.02; N1/N2, p < 0.0001; N1/N2/LRR, p < 0.001) and tumor grade 3/4 (N1/N2/LRR, p < 0.01). A regression tree analysis was then used to separate patients into risk groups with respect to N1/N2/LRR.Conclusion: In inoperable non-small cell lung cancer, the patients for whom mediastinal radiation therapy may most likely be indicated are those with a positive preoperative bronchoscopy, especially with large (> 3 cm) primary tumors.

Pathological and Karyotypic Abnormalities in Advanced Gastric Carcinomas

Twenty samples of stomach cancers were analyzed by conventional cytogenetic and histopathological techniques. Nineteen tumors were diagnosed as adenocarcinomas and one as an adenosquamous carcinoma. Multiple and complex chromosomal abnormalities were found in the cases evaluated cytogenetically. This heterogeneity of chromosomal changes appears to indicate a certain correlation with tumor progression. Histological analysis showed a distinctive growth pattern of gastric cancer samples and a potential for invasiveness and recurrence for all tumors as well as a poor prognosis.

Immunotoxicological assessment of cyclosporin A by conventional pathological techniques and immune function testing in the rat.

1. Groups of male rats were given different doses of cyclosporin A, ranging from the maximum tolerated dose (20 mg/kg/day) downwards, 7 days a week for 28 days using a protocol derived from OECD test guideline 407. 2. At the end of the test, one set of animals underwent a detailed necropsy and histopathological examination of lymphoid tissues. Immune function was assessed using the lymphoproliferative response and natural killer cell activity of their spleen cells. Another set of animals was immunised with sheep erythrocytes on day 25 and used to evaluate the ability to produce specific anti-sheep red blood cell antibody. 3. Cyclosporin A produced detectable effects on the immune system at all doses and at doses lower than other toxic effects. Both histopathological techniques and one of the immune function tests were able to identify changes at the lowest dose, 1.25 mg/kg/day. 4. The results of this investigation suggest that conventional histopathological techniques, if applied to a range of lymphoid organs, are sufficient to identify potential immunotoxicants without recourse to immune function tests.

Mode of spread in the early phase of lymphatic metastasis in non-small-cell lung cancer: Significance of nodal micrometastasis

The impact of lymphatic micrometastases on prognosis of non-small-cell lung cancer has not been clearly established. We therefore prospectively assessed the frequency, mode of mediastinal spread, and prognostic significance of lymphatic micrometastases in lymph nodes of 93 patients with completely resected non-small-cell lung cancer staged as pT1 to pT4 pN0 and pN1 by conventional histopathologic techniques. Frozen tissue sections from 471 lymph nodes that were staged as free of metastases by routine histopathologic examination were screened for micrometastases by the alkaline phosphatase–antialkaline phosphatase immunostaining technique with the monoclonal antibody Ber-Ep-4. Twenty of 73 patients (27.4%) with disease staged as pN0 and nine of 20 patients (45.0%) with disease staged as pN1 had nodal micrometastases. Eight of 17 patients with upper lobe primary tumors and five of 12 patients with lower lobe primary tumors exhibited skip micrometastases. Mean relapse-free survival was significantly increased in patients with pN0 disease without micrometastases (41.1 vs 29 months, p = 0.0081). In patients with pN1 disease, mean relapse-free and cancer-related survivals were also significantly increased if no micrometastases were found (34.8 and 38.2 months vs 18 and 23.5 months, p = 0.0157 and p = 0.0094). Patients with disease staged as pN0 and pN1 with micrometastases revealed no difference in cancer-related survival compared with a control population of patients with disease staged as pN2. The mode of spread was erratic. The prognosis of patients after upstaging of pN0 and pN1 disease according to results of immunohistochemical staining correlated strongly with the prognosis of patients whose disease was staged at the higher stages by conventional histopathologic examination. These findings could represent a new indication for adjuvant therapy, supporting extensive lymph node sampling for staging purposes. (J T HORAC C ARDIOVASC S URG 1996;112:623-30)

A histomorphologic study of the effects of periodontal inflammation on the maxillary sinus mucosa.

Twenty blocks of human jaws obtained at autopsy and containing maxillary molar teeth with the contiguous maxillary sinus intact were prepared utilizing conventional histopathologic techniques and were studied by light microscopy. The purpose of this investigation was to confirm earlier clinical reports suggesting a close association between human periodontitis and maxillary sinus thickening and to morphologically document the nature of the sinus changes. Seventeen of 20 jaw specimens demonstrated moderate to advanced periodontal destruction with pervasive extension of the inflammatory infiltrate through the alveolar process beyond the apices of the teeth and extending to the region of the antrum. Of the 20 histologic specimens, 10 showed extensive thickening of the sinus membrane, 9 had moderate hyperplastic changes, and only 1 specimen demonstrated a normal appearing sinus. Pathologic changes in the sinus membrane included inflammatory cell infiltration, edema, fibrosis of the tunica propria, mucous-serous gland proliferation, interstitial pseudo-cyst formation, polyp formation, hyalinization of the connective tissue lining, thrombosis of blood vessels, and metaplastic and degenerative changes in the epithelial lining. This study, based on histopathologic changes, suggests an apparent direct relationship between moderate and severe periodontitis of the maxillary molar teeth and pathologic changes resulting in thickening of the maxillary sinus mucosa.

Immunohistochemical and histopathological study of experimental rabies infection in mice.

An immunohistochemical and histopathological study using the ABC technique was carried out to examine time-sequential virus spread in the central nervous system (CNS) of mice after inoculation with the CVS strain of fixed rabies virus by different routes; intracerebral (ic), intraocular (io), intranasal (in), intramuscular (im) and subcutaneous (sc). Only the ic and io inoculations caused fatal infections, so that detailed analysis was conducted on mice inoculated by these two routes. In ic-inoculated mice, viral antigens were detected mainly in neurons in the cerebral cortex and in the pyramidal cells and granular cells of the hippocampus. After io inoculation, viral antigen was first detected in the trigeminal nerve ganglia, following which it spreads to the cerebral cortex and cerebellum. In the hippocampus only a few cells were viral antigen-positive at the early stage after io inoculation. There were no inflammatory lesions or Negri bodies in the CNS of mice infected by either route. This suggests that clinical signs such as ataxia or depression leading to death may be due to the direct effect of the virus on the functions of neural cells, but not to inflammatory reactions. The ABC method will be useful for the early diagnosis of suspected patients or animals to have the disease when conventional histopathological and immunofluorescent antibody techniques can not detect lesions or viral antigens.

Pulmonary Carcinogenesis in Transgenic Mice

Use of genetically engineered mice offers a unique approach to identifying and investigating factors that may influence tumor development. We have used conventional histopathologic and ultrastructural techniques to characterize lung tumors in three lines of transgenic mice bearing an albumin enhancer/promoter linked to a mutated human H-ras gene. Mice in all three lines developed multiple alveolar-bronchiolar (A/B) adenocarcinomas that are eventually lethal. The large diversity in tumor morphological features and differential tumor growth rates suggests that secondary events contribute to tumor phenotype and biological behavior. Two of the transgenic lines developed numerous A/B neoplasms within 6 to 8 weeks and thus may be useful animal models for testing potential anticancer chemotherapeutic agents. The other line lived for approximately 10 months, had fewer A/B tumors, but also developed bronchiogenic tumors. All three transgenic lines may be useful models for studying factors that affect lung tumor development.

Morphometric Study of Muscle in Congenital Idiopathic Club Foot

In congenital idiopathic club foot gross morphological changes cannot be assessed in muscle tissue by conventional histopathological techniques. Since, however, recent studies have indicated the presence of neuromuscular anomalies with preponderance of Type 1 fibres in this condition, we have performed histochemical, morphometric and electron microscopic examinations in muscle biopsies of 23 patients with congenital idiopathic club foot deformity. The age of the patients varied between 6 weeks and 12 years, respectively. Muscle biopsy was taken mainly from the flexor group of the affected leg(s) during the surgical correction of the anomaly. No gross pathological changes could be found by histochemical analysis. Morphometric study, however, disclosed abnormalities in the composition of the fibre types. The most prominent change was the percentual increase in Type 1 and decrease in Type 2 fibres in almost all the cases. Electron microscopically, only minor fine structural changes could be found. Since these changes could be assessed soon after birth just as in the later course, they cannot be regarded as the consequence of the abnormal position of the leg. More probably, Type 1 fibre predominance is related etiologically to the congenital club foot deformity.

Control of excisional margins by conventional histopathological techniques in the treatment of skin tumours. An alternative to Mohs' technique.

For histological control of excisional margins, routinely fixed tumour specimens or, under certain conditions, specimens fixed immediately in warm formalin are processed in the histology laboratory. Strips are then cut from the undersurface, edge, and cross-section of the remainder of the specimen and processed further by routine paraffin techniques until H&E-stained sections of the entire periphery and mid-section are available. We suggest that the method is simple, easy to apply, and suitable for the assessment of excisional margins of a variety of skin tumours. Extremely low recurrence rates over a relatively long follow-up period substantiate the effectiveness of the method.

Characterization of Four Main Cell Types in Gastric Cancer: Foveolar, Mucopeptic, intestinal Columnar And Goblet Cells: An histopathologic, histochemical and ultrastructural study of “early” and “advanced” tumours

Gastrectomy specimens of 148 gastric cancers, 40 of them being intramucosal or microinvasive, 27 penetrating the submucosa and 81 invading the muscularis propria, with or without involvement of the serosa and perigastric tissues, have been investigated with conventional histopathologic techniques, mucin histochemistry and electron microscopy to characterize the various lines of tumour cell differentiation and to correlate these with the histologic patterns of tumour growth. More or less differentiated intestinal columnar, intestinal goblet, gastric foveolar or mucopeptic cells were recognized in most tumours, of glandular, diffuse or mucoid type. Although simultaneous expression of more than one cell type into the same tumour occurred very frequently, intestinal columnar cells were more prominent in tubular adenocarcinomas, goblet cells (especially of colorectal type) in mucoid cancers, mucopeptic cells in diffuse cancers of invasive desmoplastic type and foveolar cells in diffuse cancers of intramucosal signet-ring cell type. In general, an increased tendency to foveolar cell differentiation and a reduced tendency to mucopeptic differentiation has been found in intramucosal cancers as compared to invasive cancers. It is concluded that the type of tumour cell differentiation, which might have some influence on the natural history of gastric cancer, is better related with more defined tumour subtypes than with the usually recognized glandular or diffuse patterns.

Correlation of microstructures and open-circuit potentials of gold-iron alloys with their in-vivo corrosion behavior.

AbstractThe in vitro behavior of a number of Au–Fe precipitation‐hardenable alloys have been investigated in distilled water and in Ringer's solution (simulating the extracellular body fluids) by the open‐circuit potential versus time method. The in vivo behavior of these materials as muscle implants has been studied by conventional histopathological and histochemical techniques. Optical and electron microscopic techniques have been used to study the extent and morphology of massive discontinuous precipitation as well as the mode of corrosion attack. A clear correlation has been established between the microstructural features presented by a given alloy and the time‐dependent open‐circuit potential and in vivo corrosion behavior. It can be concluded for this alloy system that the microstructure and the open‐circuit potential pattern may be taken to be a reasonable indication of the expected in vivo corrosion behavior.

Functional distention of the kidney in perinephritic hypertension

One kidney of dogs was wrapped in collodion-soaked bandages and the other removed. This caused malignant hypertension, and usually, fatal uremia in about seven days. The fluids draining from the incarcerated kidneys, after the artery and vein had been simultaneously clamped, were analyzed for volumes and hematocrits a few days postoperatively. The volume draining was reduced to 18 ml. per 100 Gm. of functionally distended kidney, as compared with 31 ml. per cent for normal dogs or for dogs after uninephrectomy. Both vascular blood and interstitial fluid were involved in this reduction. A reduction to 21 ml. per cent was found compatible with life. But a reduction to 16 ml. per cent was incompatible with life, for the animals soon died in fatal uremia. Severe reduction in the volume of interstitial fluid was apparently the critical change in the latter case. It is the reduction in functional distention, it is postulated, which is the stimulus to the kidney's own feed-back mechanism of renin secretion; this usually restores functional distention to normal by inflating the kidney with a higher blood pressure. But in the present experiment, this was impossible because of the straight-jacketing effect of the incarcerating collodion hull. The failure of distention then led to malignant hypertension, and finally, when hypertension was extreme, to the inflexible behavior of the kidney which is characteristic of fatal uremia. At autopsy, the animals were found to have the massive necrotizing arteriolitis characteristic of death with malignant hypertension. However, in the kidneys there was no histopathologic change. Evidently, the renal morphologic change responsible for the hypertension, and also for the uremia, was a functional change only: it could not be visualized by conventional histopathologic techniques. The theory is proposed that the critical hemodynamic defect in the kidney that leads to renal hypertension is reduction in the kidney's natural distention. This may happen in a variety of ways: by an incarcerating hull, as in the present experiment; or by partial arterial constriction, with consequent reduction in the inflating action of the blood pressure; or by the constraining effect of cicatrization and contraction in renal inflammation; or by decline in the kidney's natural elasticity with age. All lead to the same response of formation of angiotensin (and other still obscure reactions) which induces hypertension.