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Biomedical subjects

M Abdulla

Publications and source records attributed to M Abdulla.

At least 19 recordsLinked to original sources
PubMed2000

Cytomorphologic features of classic and variant lobular carcinoma: A comparative study.

There are several subtypes of lobular carcinoma (LC), and their cytomorphologic features differ from classic lobular carcinoma (CLC). The finer details of the differences between CLC and variant lobular carcinoma (VLC) have not been adequately studied. A comparative study of 54 cases of CLC and VLC was done in order to verify any statistically significant differences between them. All cases had histologic confirmation of the diagnosis. Six parameters, which included cellularity, signet-ring cells, intracytoplasmic lumina (ICL), anisonucleosis, cell size, and prominent nucleoli, were studied. The only statistically significant findings were cellularity and cell size when compared to CLC. The cellularity in VLC was higher and the cells in VLC were larger when compared to CLC. There are no definite diagnostic features to identify VLC; however, in a cellular specimen with plenty of large cells with other features of LC, one should have a high index of suspicion of VLC.

Biopsy, Needle↗
PubMed2000

Role of diet modification in cancer prevention.

Carcinogenesis encompasses a prolonged accumulation of injuries at several different biological levels and include both genetic and biochemical changes in the cells. At each of these levels, there are several possibilities of intervention in order to prevent, slow down or even halt the gradual march of healthy cells towards malignancy. Diet modification is one such possibility. A number of natural foodstuffs, especially fruits and vegetables contain substantial quantities of molecules that have chemopreventive potential against cancer development. Such compounds include vitamins, trace elements and a variety of other molecules with antioxidant properties. Carotenoids, flavanoid polyphenols, isoflavones, catechins, and several other components that found in cruciferous vegetables are molecules that are known to protect against the deleterious effect of reactive oxygen species. A number of epidemiological and experimental studies have shown that vitamin C and E, Beta-carotene and the essential trace element selenium can reduce the risk of cancer. Consistent observations during the last few decades that cancer risk is reduced by a diet rich in vegetables, fruits, legumes, grains and green tea have encouraged research to identify several plant components especially phytochemicals that protect against DNA damage. Many of these substances block specific carcinogen pathways. Dietary supplements are part of an overall health program, along with a high intake of fruits and vegetables that help to combat damage to cells, which in turn may initiate cancer development. This paper will review current knowledge concerning diet modification and cancer prevention with special reference to minerals and trace elements.

Anticarcinogenic Agents↗
PubMed1998

Blood levels of copper, iron, zinc, and lead in adults in India and Pakistan and the effect of oral zinc supplementation for six weeks.

Deficiency in the intake of trace elements, such as copper (Cu), iron (Fe), selenium (Se), and zinc (Zn), is very common in the general population of most developing countries. A preliminary study in India and Pakistan showing the plasma levels of Zn and Fe indicates that approx 50% of the subjects who participated have low levels of both Fe and Zn, suggesting a marginal deficiency. The low plasma levels of these elements are more pronounced in females. The mean levels of Ze, Cu, and Fe in the plasma of 83 subjects were 0.71 +/- 0.11, 0.96 +/- 0.10, and 0.80 +/- 0.12 mg/L, respectively. The Cu:Zn ratio in the plasma was 1.43 +/- 0.16. Three groups of 15 subjects each were given three different levels of oral supplements of Zn (15, 30, and 45 mg of Zn as Zn gluconate) for 6 wk, and blood samples were analyzed during various intervals. Plasma concentration of Zn increased significantly (p < 0.001) in all the groups after 4 wk of supplementation and reached almost normal levels after 6 wk. Along with the increase in Zn, there was a significant decrease (p < 0.001) in plasma Cu levels. There were no changes in the concentration of Fe during the supplementation period. The supplementation was well tolerated by most subjects. The results of this pilot study indicate that Zn supplementation is a practical possibility comparable to that of Fe supplementation in order to prevent marginal Zn deficiency in vulnerable groups in the general population of developing countries.

Administration, Oral↗
PubMed1996

Paraquat induced DNA damage by reactive oxygen species.

The redox cycling contact herbicide paraquat (PQ) causes oxidative damage to pulmonary tissue. PQ is reduced enzymatically to PQ radical in lung where it reacts with molecular oxygen, generating reactive oxygen species (ROS). ROS damage various macromolecules including DNA. However, the ability of paraquat to mediate DNA damage is unknown. In this study, Bam H1 site (5'-GGATCC-3') on pBR322 DNA was chosen as the target sequence for a study of the PQ-mediated DNA damage. The incubation of PQ with plasmid DNA in the presence of freshly prepared rat lung microsomes and NADPH resulted in damage to the restriction site. The PQ-treated DNA was not digested with the endonuclease reflected by the digestion pattern of DNA on agarose gels. The effect was dependent on the dose of PQ. The PQ-mediated damage to DNA was comparable to DNA damage caused by ROS generated through the xanthine-xanthine oxidase system. The results of the present study suggest that ROS generated by PQ in vitro under aerobic conditions may lead to a modification of the restriction site on DNA.

DNA Damage↗
PubMed1995

Evidence that in situ generated reactive oxygen species act as a potent stage I tumor promoter in mouse skin.

A body of indirect evidence has suggested the involvement of reactive oxygen species (ROS) in tumor promotion. However, direct evidence for the involvement of in situ generated ROS in tumor promotion is lacking at present. This study provides the first in situ evidence for the involvement of ROS in stage I tumor promotion. Earlier we have shown that parenteral administration of Photofrin-II (a mixture of porphyrins) to mice followed by their exposure to visible light generates ROS. In this study we further provide E.S.R. spectral evidence that both O2.- and .OH radicals are generated during tissue photosensitization. The free radicals/ROS generation is followed by the development of cutaneous inflammation which is maximum at six hours after photosensitization and develops in a dose dependent manner. The epidermal myeloperoxidase activity which represents neutrophil infiltration is also increased more than 160% of the control value. The histopathology of skin tissues of 7,12 dimethyl benz(a)anthracene initiated mice receiving multiple treatments of Pf-II and light for a period of four weeks indicates pronounced epidermal hyperplasia, glandular hyperplasia, dark basal keratinocytes induction characterized by the high uptake of the dye and frequent neutrophil infiltrations. Our data indicate that ROS generated in situ as a result of porphyrin-mediated cutaneous photosensitization results in the development of changes characteristic of stage I tumor promotion in murine skin.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1995

Evaluation of malondialdehyde as an index of lead damage in rat brain homogenates.

Lipid peroxidation in vitro homogenates of brain was examined as sequela of lead toxicity. The levels of malondialdehyde (MDA) in homogenates of rat brain (1 ml, 5% w/v) treated with lead (50 micrograms) alone or in combination with ascorbic acid (100 micrograms), alphatocopherol (100 micrograms) or hydroquinone (100 micrograms) were evaluated. The levels of MDA were consistently evoked by lead in a dose-related manner. The toxicity of lead was further advanced by the action of the pro-oxidant drug ascorbic acid on the brain. However, the anti-oxidant drugs alphatocopherol and hydroquinone decreased the toxic effect of lead on the brain. These results clearly show that the enhanced lipid peroxidation may provide a basis of lead-induced neurotoxicity.

Animals↗
PubMed1994

The argyrophilic nucleolar organizer regions in ductal carcinoma in situ of the breast. The significance of ploidy and proliferative activity analysis using this silver staining technique.

BACKGROUND: Two interphase argyrophilic nucleolar organizer region (AgNOR) counts have been correlated with ploidy and proliferative activity in patients with ductal carcinoma in situ (DCIS) of the breast. The first is the mean number of AgNORs (mAgNOR); it reflects ploidy. The second is the percentage of nuclei with greater than or equal to five AgNORs/nucleus (pAgNOR); it correlates with proliferative activity. DCIS of the breast is a heterogeneous group of lesions that is not associated uniformly with invasive ductal carcinoma. A significant number of patients with DCIS will, however, progress to invasive ductal carcinoma. Factors identifying the invasive potential of DCIS in these patients have not been defined clearly. The authors postulated that pAgNOR in DCIS may predict the invasive potential of these lesions. METHODS: The authors studied 86 cases of DCIS of the breast by the AgNOR silver stain using the two above-mentioned counts. RESULTS: There were 54 comedo and 32 noncomedo DCIS cases. Forty-one cases (47%) were associated with invasive ductal carcinoma. Thirty cases of comedo DCIS (55%) showed mAgNOR counts suggestive of aneuploidy (> or = 2.4/nucleus), whereas only seven cases of noncomedo DCIS (22%) showed such counts (P = 0.001). Cases associated with invasion had higher incidence of aneuploid mAgNOR counts (P = 0.0003). The pAgNOR counts in comedo DCIS ranged from 1% to 36% (median, 11%), whereas in noncomedo DCIS pAgNOR counts ranged from 0% to 22% (median, 7%) (P = 0.007). The 41 cases associated with invasion had pAgNOR counts ranging from 3% to 36% (median, 12%), whereas those not associated with invasion had pAgNOR counts ranging from 0% to 24% (median, 5%) (P = 0.000001). This difference was irrespective of the type of DCIS or mAgNOR counts. CONCLUSIONS: Comedo DCIS of the breast may show a higher incidence of aneuploidy and increased proliferative activity and invasive ductal carcinoma than does noncomedo DCIS. Ploidy and proliferative activity, measured by AgNOR staining in DCIS, may have a significant predictive value in identifying the invasive potential of these lesions.

Breast Neoplasms↗
PubMed1994

Trace element contents in food determined by neutron activation analysis and other techniques.

Advances in analytical methodology and sophisticated instrumentation introduced during the last few decades have not only helped to recognize the presence of a large number of essential and toxic trace elements in biological materials and food stuffs, but also added a new dimension in our understanding of their role in health and disease. In deficiency states, most essential trace elements cause health problems. The trace element problem as a public health issue has a very low priority in developing countries. Daily dietary intake data based on well-conducted studies are limited in many parts of the world. The present authors are in the process of generating data for the intake levels of a number of major and minor inorganic elements both in developed and developing countries. The results so far obtained show wide variations. The intake levels of several elements, including potassium, magnesium, zinc, copper, and selenium, are below the current recommended levels. The concentration of toxic metals, such as aluminum, cadmium, lead, and mercury, are within acceptable limits in most of the diets analyzed.

Adolescent↗
PubMed1994

Validation of the cumulative or replicate NAA method for the determination of trace elements in biological materials.

To make the best use of time and facilities, a neutron activation system, fully automatic, including spectrum and data processing, to be used with short-lived nuclides, has been recently developed at the Portuguese Research Reactor (in Portuguese "Reactor Portugês de Investigação," RPI). Using this system, the cumulative neutron activation analysis method is now being implemented. This article summarizes the experimental procedures used to validate the cumulative NAA method for the determination of selenium in biological samples, emphasizing the determination of the essential characteristics of precision, accuracy, and limits of detection and of quantification of the method. The article also examines how detection limits and precision are improved when the samples are analyzed by this method compared to the cyclic activation measurements in use at RPI for the determination of selenium. The improvement is demonstrated for the measurement of selenium in several reference materials when the result obtained by adding up seven spectra of separate aliquots of the same sample is compared to the result from a cumulative spectrum of seven (whenever possible) consecutive cycles of a single sample.

Animals↗
PubMed1994

Role of DNA content determination by image analysis in confirmation of dysplasia in Barrett's esophagus.

Progression to cancer in Barrett's esophageal columnar metaplasia is classically heralded by the presence of epithelial dysplasia. Differentiation of reactive epithelial atypia and mild dysplasia from severe dysplasia, however, may often be difficult especially with limited biopsy material. We performed DNA content analysis of 11 cases of Barrett's esophagus showing variable reactive atypia, 24 cases of Barrett's with low- and high-grade dysplasia, and 30 cases of Barrett's with invasive adenocarcinoma (BCA) using Feulgen-stained paraffin sections and the CAS 200 image analyzer. The mean DNA index of the uniformly diploid BE was 1.06. The 1.26 mean DNA index for the low-grade Barrett's esophagus with dysplasia, 1.62 for high grade, and 1.88 DI for BCA were significantly greater than for variable reactive atypia (P < 0.004) but not different from each other. Six BCA cases (20%) were diploid; 24 cases (80%) were aneuploid. Mean survival of diploid BCA at 20.4 mo was nearly double the survival of 10.6 mo for aneuploid BCA. However, this difference was not statistically significant (P < 0.21) and survival at 3 yr was identical for all BCA cases. Tumor grade, stage, and lymph node status did not significantly correlate with ploidy pattern. Thus, although DNA analysis does not seem to predict ultimate outcome in BCA, aneuploidy and high DNA index are associated with Barrett's esophagus with dysplasia and BCA and may be of significant value in the differentiation from variable reactive atypia in small biopsies.

Adenocarcinoma↗
PubMed1994

Renal angiomyolipoma. DNA content and immunohistochemical study of classic and multicentric variants.

Angiomyolipomas (AMLs) are polymorphic renal tumors that are composed of mature tissues and frequently associated with tuberous sclerosis; AMLs have long been considered hamartomatous in nature. We report the routine histologic and immunohistochemical features and DNA content analysis of two fatal cases of renal giant multicentric AML with distant organ involvement, and we contrast the findings with those of four similarly studied cases of classic solitary AML. Severe nuclear pleomorphism, significant mitotic activity, and necrosis, which are all characteristics of multicentric AML, were not seen in the cases of classic AML. Quantitation of DNA by image analysis of Feulgen-stained slides from paraffin-embedded blocks revealed an aneuploid pattern in the two cases of multicentric AML and an aneuploid pattern in one of the four cases of classic AML. Tumors in the liver, spleen, and lungs in one of the cases of multicentric AML were diploid. Immunohistochemical analysis revealed positive staining reaction of vascular and adipose tissue components with HMB-45 antibody in three of the six cases of AML. We conclude that AMLs may occur in a sarcomatous, infiltrating multicentric form involving multiple organs, that aneuploidy may be seen in lesions of both the multicentric AML and classic AML variants, that AMLs may feature DNA ploidy heterogeneity in multiple-organ sites, that HMB-45 immunoreactivity may be encountered in AMLs without evidence of nevomelanocytic differentiation, and that continued study of AMLs is needed to clarify further the histogenesis, lineage, clonality, and malignant potential of these tumors.

Adult↗
PubMed1993

Histologic and ultrastructural features of experimental duodenal ulcers in Sprague-Dawley rats.

The histologic and ultrastructural features of a time sequence study of the development, evolution, and healing of acetic acid-induced experimental duodenal ulcer are presented. Duodenal ulcers produced by serosal application of acetic acid featured microvascular injury with progressive disintegration of the tips of the mucosal villi and subtotal necrosis of the duodenal wall. At 3 days ulcers transformed into a chronic state with regenerating epithelium originating from the crypts of the intact bordering mucosa extending toward the center of the ulcers. By 21 days healed ulcers were covered by distorted duodenal surface mucosa. We conclude that this reproducible and standardized model of duodenal ulcer features vascular injury as the earliest microscopic event, that ischemic necrosis leads to ulceration, and that the chronic phase bears morphologic resemblance to human duodenal ulcer.

Animals↗
PubMed1993

Sulfur-rich prostatic intraluminal crystalloids: a surgical pathologic and electron probe x-ray microanalytic study.

Prostatic intraluminal crystalloids are irregular eosinophilic, non-birefringent structures increasingly recognized as potential indicators of prostatic malignancy. In a study of 250 randomly selected surgical pathology cases of prostatic tissues none of 50 cases of benign glandular hyperplasia (0%), one of 50 cases of atypical adenomatous hyperplasia, 18 of 50 cases of well-differentiated adenocarcinoma (36%), seven of 50 cases of moderately differentiated adenocarcinoma (14%), and none of 50 cases of poorly differentiated adenocarcinoma (0%) revealed intraluminal crystalloids. A histochemical and immunohistochemical staining panel indicated that the crystalloids were nonproteinaceous. Crystalloids were stained intensely with phosphotungstic acid hematoxylin and did not stain for prostatic-specific antigen or hemoglobin. Crystalloids were clearly differentiated from prostatic corpora amylacea on light microscopy, histochemistry, scanning, and transmission electron microscopy. Electron probe x-ray microanalysis of 10 cases of crystalloids revealed uniform high sulfur peaks and small sodium peaks. We conclude that intraluminal crystalloids are associated more frequently with low-grade prostatic adenocarcinoma, may occur in benign tissue bordering adenocarcinoma, are predominantly composed of inorganic sulfur, and their presence in benign and atypical prostate biopsies may be of pathologic significance and should warrant further clinical investigation and possibly repeat biopsy.

Adenocarcinoma↗
PubMed1993

Nuclear DNA content and clinical follow-up in resected pancreatic adenocarcinoma.

Nuclear DNA content was determined by image analysis of paraffin-embedded tissue sections in 20 cases of resected pancreatic ductal adenocarcinoma. Seven cases (35%) showed a diploid pattern; 13 (65%) were aneuploid. Mean survival time of patients with diploid tumors was significantly greater (17 months) than for patients with aneuploid carcinomas, 7.5 months (P < .03, Kaplan-Meier and Cox univariate analysis). Patient age, grade of differentiation, primary tumor size and lymph node status did not correlate significantly with ploidy pattern and survival. In four cases atypical hyperplasia/adenocarcinoma in situ was present in the main duct epithelium at the pancreatectomy resection line. These intraductal foci were uniformly diploid. We conclude that despite the uniform fatality of pancreatic cancer, adenocarcinomas with aneuploid patterns pursue a significantly more rapid and aggressive clinical course than do diploid tumors and that the atypical intraductal epithelial foci that may accompany resected specimens from invasive adenocarcinoma are DNA diploid, may represent noninvasive precursor lesions and are of uncertain clinical significance.

Aged↗
PubMed1989

Organ sequestration of 65Zn during experimental sepsis.

Alteration in the metabolism of zinc during infections has been reported. We have studied the redistribution of endogenous zinc by making the animals physiologically stable by daily intra-gastric administration of 65Zn prior to the induction of sepsis. Organ uptake of exogenous zinc was studied by investigating the organ uptake of 65Zn after an intravenous injection during sepsis. Male Sprague-Dawley rats, were kept in metabolic cages to monitor the excretion of the radioisotope. They were made septic using a gelatine capsule containing E. coli, Bacteroides fragilis in a standardised mixture with sterile rat faeces and barium sulphate, implanted into the abdomen. The plasma radioactivity in the septic state was significantly lower when compared to control rats. In the septic state, there was an increased uptake of endogenous zinc after oral administration of radioactive zinc in the liver, pancreas, large intestine and testes. When administered intravenously in septic animals we found a decreased uptake of exogenous zinc in the pancreas, large intestine, small intestine, bone and testes. Thus the distribution of endogenous and exogenous zinc seems to differ during the septic state.

Journal Article↗
PubMed1989

Thioacetamide- and carbon tetrachloride-induced liver cirrhosis.

Two methods of inducing liver cirrhosis in the rat were studied. Intragastric administration of CCl4 for 16 weeks according to Proctor and Chatamra was compared to the administration of thioacetamide in the drinking water (0.3 g/l) for the same period. CCl4 administration induced micronodular cirrhosis in 6/8 animals with a 27% mortality. Thioacetamide induced cirrhosis in 6/8 animals without mortality. The histologic pictures differed somewhat in that the CCl4 group exhibited more necrosis and cellular swelling while the thioacetamide group had more nuclear atypias and proliferation. Biochemically both groups had elevated plasma levels of aspartate aminotransferase. The lysosomal enzyme beta-hexosaminidase (beta-NAG) showed a transient increase in the thioacetamide animals, while beta-glucuronidase decreased. CCl4-induced cirrhosis led to an increase in beta-NAG. Plasma zinc decreased in both groups as well as liver zinc content in the CCl4 group, while there was a continuous elevation of liver zinc in the thioacetamide group. We conclude that oral administration of thioacetamide is a simple and reliable method of inducing experimental liver cirrhosis. The differences in histological appearances and some biochemical parameters may be caused by the different mechanisms of action of thioacetamide and CCl4.

Acetamides↗