Cell block as an adjunct to conventional Papanicolaou smear for diagnosis of cervical cancer in resource-limited settings

OBJECTIVE: To assess the utility of indigenously prepared cell blocks (CBs) as an adjunct to a conventional smear test in providing a reliable diagnosis of clinically suspicious cervical cancer in resource-limited settings. METHODS: Eighty-six clinically suspicious cervical cancer cases underwent a conventional smear test, CB preparation from residual cellular samples and biopsies at the same sitting. Correlations were performed between these modalities in order to derive the sensitivity and specificity of the CB technique to diagnose cervical cancer. OBSERVATION & RESULTS: Out of 86 clinically suspicious cervical cancers, 72 (83.7%), 70 (81.4%) and 67 (77.9%) cases were diagnosed as malignant on tissue biopsies, CBs and smears respectively. CB-biopsy agreement in the diagnosis of malignancy was feasible in 87.5% of the cases while CB-Pap smear agreement was feasible in 92.5% of the cases. Sensitivity and specificity of CB preparation to diagnose malignancy was 92.5% and 100%, respectively, when the smear was taken as the reference test (excluding the unsatisfactory smears). When biopsy was taken as the gold standard, the sensitivity and specificity of CBs were 87.5% and 100% respectively (excluding the unsatisfactory biopsies). In 8/19 cases where the smear diagnoses were either unsatisfactory or atypical squamous cells/atypical glandular cells, CBs picked up malignant lesions. CONCLUSION: CBs prepared from the residual cellular sample of conventional cervical scrapes augment the sensitivity of the smear test. When used as an adjunct to the smear, CBs aid in providing a reliable diagnosis of cervical cancer in the majority of the clinically suspected cases and thus the biopsy load can be reduced significantly in resource-poor settings.     

Cytokine-Induced Accumulation of Very Long-Chain Fatty Acids in Rat C6 Glial Cells: Implication for X-Adrenoleukodystrophy

Abstract: X-Adrenoleukodystrophy (X-ALD) is an inherited metabolic disorder of very long-chain fatty acids (VLCFA) with subsequent manifestation of neuroinflammatory disease. To investigate the possible role of proinflammatory cytokines in the X-ALD disease process, we examined the effect of cytokines on the metabolism of VLCFA in C6 glial cells expressing oligodendrocyte-like properties. C6 glial cells under serum-free conditions were treated with different combinations of cytokines (tumor necrosis factor-α, interleukin-1β, interferon-γ) or cytokine with bacterial lipopolysaccharide (LPS). Cytokine-treated C6 cells had higher concentrations of VLCFA, measured as percent weight and also as C_26:0/C_22:0 ratio, which were 300–400% as compared with the controls. We also found increased levels of C_26:1 in cytokine-treated cells. The accumulation of VLCFA paralleled the decrease (35–55%) in peroxisomal β-oxidation activity and a 12- to 14-fold increase in the production of nitric oxide (NO). Individual cytokines were unable either to produce NO or to increase the levels of VLCFA in C6 cells. Inhibition of cytokine-induced NO production by l -N-methylarginine, an inhibitor of NO synthase (NOS), and N-acetylcysteine, an inhibitor of cytokine-mediated induction of inducible NOS, normalized the peroxisomal β-oxidation activity and the levels of VLCFA, suggesting a role for the proinflammatory cytokines and NO toxicity in the neuropathological changes associated with abnormal VLCFA metabolism (e.g., X-ALD). X-ALD is a peroxisomal disease having deficient oxidation of VLCFA, resulting in the excessive accumulation of VLCFA in all tissues but especially in brain. We observed greater increase in levels of VLCFA in the inflammatory region of ALD brain (in the demyelinating plaque and the area around the plaque) than in the normal-looking area away from the plaque; this also indicates that cytokines in the proinflammatory region may augment the VLCFA defect caused by the inherited abnormality in X-ALD brain. Although C6 glial cultured cells do not reflect the X-ALD model precisely, the observed relationship between the cytokine-induced inhibition of the oxidation of VLCFA, excessive accumulation of VLCFA, and excessive production of NO and their normalization by inhibitors of NOS in C6 glial cells suggests that NO-mediated toxicity may play a role in VLCFA-associated neuroinflammatory diseases (e.g., X-ALD).     

A study of the enzymatic profile of soil isolates of Nocardia asteroides

In this study, using the API-ZYM system, we have reported the enzyme profile of 42 soil strains and 2 clinical strains of Nocardia asteroides isolated locally. Of the 19 enzymes tested, only 7 were demonstrable in over 90% of the soil isolates. These included alkaline phosphatase, esterase lipase, leucine arylamidase, acid phosphatase, phosphohydrolase, α-glucosidase and β-glucosidase. In addition, β-galactosidase activity was demonstrated in all the strains by the O-nitrophenyl-β-D-galactopyranoside (ONPG) test. The enzymes which were not demonstrable in >95% of the strains included valine arylamidase, cystine arylamidase, trypsin, chymotrypsin, α-galactosidase, β-glucoronidase, N-acetyl-β-glucosaminidase, α-mannosidase and α-fucosidase. With the exception of valine arylamidase, which was lacking in all but one isolate, the enzyme profiles of the soil isolates were comparable with the clinical isolates of N. asteroides reported in previous studies. The reasons for this difference in the two sets of isolates is not clear. The study reinforces the view that specific differences in the enzymatic profiles of Nocardia species could be used for their rapid identification. However, more extensive studies are needed to establish the reproducibility of this method. To the best of our knowledge, this is the first study of the enzymatic profile of soil isolates of N. asteroides originating from a single geographic region. This revised version was published online in June 2006 with corrections to the Cover Date.     

A histochemical analysis of mammalian oxidative skeletal muscle fibres using the enzymes of energetic metabolism

Summary Some histochemical parameters of the three main fibre types of rat vastus lateralis muscle were studied. Succinic dehydrogenase (SDH), creatine kinase (CK), sarcotubular ATPase (SR-ATPase) and mitochondrial ATPase activities were demonstrated in serial sections. The three fibre types, recognised by the distribution pattern of SDH activity, all show high CK activity. However, red Type I oxidative fibres when examined for ATPase and ATPase dependent CK activity, show distinct heterogeneity revealing sub-populations within the same homogeneous fibre type. Three distinct patterns were recognised in the red Type I fibres depending on the distribution of the final reaction product. The present histochemical evidence confirms the fact that subdivision of mammalian skeletal muscle into three fibre types is only approximate and probably more than three types exist.     

Further histochemical properties of rabbit skeletal muscle fibres

Summary The histochemical activities of succinic dehydrogenase (SDH), creatine kinase (CK), sarcoplasmic reticular ATPase (SR-ATPase) and myosin ATPase were studied in serial sections of rabbit adductor muscle. Three fibre types were distinguished depending upon the distribution of the enzyme activities. The type II white fibres posessing minimal SDH showed high myosin ATPase, SR-ATPase and ATPase dependent CK activities. Red oxidative fibres showing high SDH fell into two distinct groups: One category had mainly a peripheral localization of SDH and showed an enzymatic profile identical to that of type II white fibres. The second category of red fibres displayed both a homogeneous distribution of small diformazan granules throughout the fibre as well as a sub-sarcolemmal collection when tested for SDH activity but possessed very low amounts of reaction product of the various enzymes of the energetic metabolism studied. Since it is well established that the myosin ATPase of a fibre correlates with its contraction time, the present histochemical investigation provides further support for this concept by demonstrating the presence of high SR-ATPase and ATPase dependent CK activities in all white and red fibres rich in myosin ATPase.