Filtration and agar embedding applied to fine needle aspirates for tumor diagnosis by electron microscopy. A combined technique.

OBJECTIVE: To develop a novel method for processing of fine needle aspirates subjected to electron microscopic (EM) study. STUDY DESIGN: Included 70 cases of poorly differentiated malignant tumors in which a definitive diagnosis was not possible on light microscopic (LM) examination and that thus required application of an ancillary technique such as FNA/EM, for diagnosis. We have established a novel method of processing, a technique of filtration through nylon mesh filters to eliminate red blood cells (RBCs) and necrotic debris, followed by agar well embedding to avoid loss of diagnostic material during processing without centrifugation at later steps after agar embedding, thus minimizing the time required for processing. It was successfully carried out in 70 cases. RESULTS: The combined technique was extremely effective in eliminating RBCs and necrotic debris. It also avoided further loss of valuable diagnostic material. An accurate diagnosis was rendered in 70 cases; that was not possible by LM alone. The whole procedure saves two to three hours of processing as centrifugation is not required after the agar embedding step. CONCLUSION: This technique was found to be cost- and time-effective, particularly suitable for developing countries, where financial resources are limited.

Role of 'cell type' in proton relaxation in normal and neoplastic lymph nodes characterized by pulsed NMR spectroscopy.

Pulsed NMR studies have been undertaken on malignant lymphomas. It has been observed that water proton spin-lattice relaxation times of lymph node tissues show increase in lymphnodes of Hodgkin's and Non-Hodgkin's lymphoma as compared to those in normal subjects. The T1 values of normal lymphnodes showed a range of 200-300 msec, while the metastatic lymphnodes showed a range of 400-600 msec at 20 MHz. These studies have brought out the importance of histopathological significance and the role of 'cell type' and biomolecules as a factor influencing water proton relaxation times. Further the relevance of the present in vitro studies to Magnetic Resonance Imaging of ex vivo images of normal and metastatic lymphnodes has become evident from some recent studies reported in normal and afflicted lymphnodes.

Significance of histopathology in pulsed NMR studies on cancer.

Characterization of tissue by pulsed nuclear magnetic resonance spectrometry opened a new area of research. The differences in the NMR parameters T1 and T2 of normal and malignant tissues constitute the basis for their distinction by pulsed NMR spectrometry and also by NMR imaging in vivo. The present studies were undertaken to correlate the role of constituent histological elements encountered in various malignancy-associated changes and T1 variations and are based on evaluation of samples taken from surgically resected specimens of carcinoma of the esophagus, comprising the uninvolved portions of the esophagus and the gastric end on gross examination. The uninvolved and involved regions showed low and high T1 values, respectively. High T1 values were also encountered in the zones of samples of uninvolved esophagus which histologically revealed areas with dysplasia. This feature, viz., dysplasia representing malignancy-associated changes, has been found to recur in many samples. Detailed histological studies provided further evidence confirming that areas with dysplasia contribute to an increase in T1 values whereas in zones at the gastric end metaplasia and hyperplasia are more common. The results are of value for demarcation of tumor area by in vivo NMR imaging.

Potentiation of hepatotoxicity by ethanol in galactosamine-induced hepatitis in rats: role of propylthiouracil protection.

Chronic ingestion of ethanol (5 g/kg/day) for 6 weeks increased the hepatotoxicity of a single injection of D-galactosamine (330 mg/kg) in rats. Plasma transaminases, alkaline phosphatase, gamma glutamyl transpeptidase and sulphobromophthalein retention were consistently high in alcohol-fed rats compared to sucrose-fed controls, 25 hours after galactosamine administration. Liver histology in sucrose-fed rats revealed typical inflammatory changes and cytoplasmic vacuolation without cell necrosis was seen. Propylthiouracil treatment had no beneficial or protective effect in alcohol-fed rats in this animal model of hepatitis.

Cell surface antigen -- a study in bladder tumours.

Thirty bladder tumours of various stages and grades were examined for the presence of A.B.O. (H) cell surface antigen using specific red cell adherence (SCRA) technique. Ten patients with stage A disease and low grade tumour (grade I) retained the antigens, whereas all patients with high stage disease (B,C,D) and high grade tumours showed absence of antigen. When these data were correlated with recurrence pattern and metastasis or invasion rate, patients who did not show the antigen at the initial visit developed metastases and had poor prognoses. The patient who had expressed the antigen by positive SCRA had fewer recurrences and a longer tumour-free interval. Hence if SCRA is done in all bladder tumours at the initial visit and at subsequent follow-up, it can be used as a biological marker.

Immune dysfunction in non-Hodgkin's lymphoma.

Immune dysfunction seems to be more common in lymphoproliferative disorders wherein the malignant cells originate from the immune system itself. The reaction of Dinitrochlorobenzene (DNCB) and six recall antigens were found to be diminished in patients with non-Hodgkin's lymphomas as compared to control subjects (P less than 0.005). The skin reactivity was lost in increasing order in well differentiated, poorly differentiated, and histiocytic types. The depression in delayed hypersensitivity was greater with generalized as compared to localized disease. In angioimmunoblastic lymphadenopathy (AIL), skin tests also showed negative response in 7 of 8 patients. This T-cell dysfunction in a preneoplastic condition (AIL) suggests early appearance of immunodeficiency and probably a prerequisite for the development of a lymphoma. The serum immunoglobulin levels failed to show any relation with respect to histology or extent of disease. Presumably, the alteration of IgG is secondary to a malignancy.

Histopathological evidence in support of the association of elevated proton spin-lattice relaxation times with the malignant state.

The pulsed nuclear magnetic resonance technique was explored for its potential diagnostic value in human cancer. Measurements of proton spin-lattice relaxation times (T1) of cellular water protons of normal and malignant esophageal tissues showed elevated T1 values in the latter. In some cases, tissues which appeared normal on gross examination assumed as uninvolved tissues had T1 values higher than the other grossly uninvolved tissues and often closer to the T1 of the corresponding tumor tissue. A histopathological study of the assumed uninvolved areas also studied for the T1 values was therefore undertaken. A preliminary study demonstrated the presence of malignant cell groups or clusters in some of the uninvolved samples with higher T1 compared to the true uninvolved tissues, which had a normal histological picture and low T1 values. This observation has brought out the importance of histopathological studies in addition to relaxation studies to comprehend contributory factors to relaxation. Secondly, it lends support to the thesis of elevated T1 values being characteristics of the malignant state.

Cellular immunity in Hodgkin's disease.

Defective cell-mediated immunity (CMI) occurs early in the course of Hodgkin's disease (HD) and may persist even two years after successful treatment. This has been confirmed by in vivo and in vitro tests performed on 51 untreated and 52 treated patients of HD. The grading of skin reponse in vivo to dinitrochlorobenzene (DNCB) correlated very well with the in vitro leukocyte migration inhibition (LMI) response against phytohemagglutinin (PHA). An inhibitory influence of HD patients' sera was demonstrated by LMI tests in vitro. The response of peripheral leukocytes from HD patients in the LMI tests could be augmented in vitro by addition of levamisole (an immuno-potentiator) to the culture medium, thus pointing to an intrinsic defect in Lymphocytes. The data indicate that defect at multiple sites in the immune system is responsible for persistent anergy in HD.