Z score analysis: A novel approach to interpretation of an erythrogram

Context: Z score defines the shift of an observed value from the mean. Aims: By determining the direction of this shift and its absolute value for mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC), one can quickly screen the hemogram for any spurious results in RBC parameters and also predict the type of anemia. This is because MCH and MCHC are derived parameters (from Hb, RBC, MCV) and thereby reflect the true as well as false changes in an erythrogram. Materials and Methods: A total of 975 hemograms were studied retrospectively. Basic statistical formulae using mean and standard deviation were applied to calculate z scores for MCH and MCHC. Results obtained were compared with the standard method and validated by an independent cohort of 100 random samples run on a different machine. Results and Statistical Analysis: Z score was found to be statistically significant (p <.001) in diagnosing iron deficiency anemias, megaloblastic anemias, hemolytic anemias, regenerative anemias, anemia of chronic disease and spurious findings. Z score was not significant (p = 0.9) in predicting beta thalassemia trait. The sensitivity was low for the differentials of microcytic hypochromic anemias. Conclusions: Despite this, Z score can be of immense help to the clinicians and pathologists in making quick interpretation of the underlying red cell abnormalities. Also, it can be used as a quality assessment tool in hematology laboratories taking pre analytical and analytical factors into account.

A clinicopathologic analysis of 88 lung resections of suspected metastatic carcinomas with proven primaries.

Background: The lung is the most common site for metastatic carcinomas. Very few studies have comprehensively analyzed all pulmonary resections for metastatic carcinomas. Aims and Objectives: To analyze all lung resections for suspected metastatic carcinomas accrued over 10 years to evaluate: The most frequent primary site, The interval between primary tumor diagnosis and lung metastases, and The proportion of inadvertently resected benign lesions, clinicoradiologically mistakenfor metastatic deposits. Materials and Methods: Between 2002 and 2011, 88 pulmonary metastasectomies were done for suspected metastatic carcinomas, which form the basis of this study. Results: In 81 of 88 cases (92%) the diagnosis of metastatic carcinoma was histologically confirmed, whereas 7 cases (8%) were non-neoplastic. The mean interval between primary tumor and metastases was 2.5 years. The primary sites were colorectum (30; 37%), kidney and breast (14; 17.3% each), cervix (9; 10%), salivary gland carcinoma (3), thyroid carcinoma (2), squamous carcinoma (2, one each of mandible and larynx), papillary urothelial carcinoma (2), hepatocellular carcinoma (1), endometrioid adenocarcinoma (1), carcinosarcoma of endometrium (1), adrenocortical carcinoma (1), and neuroendocrine carcinoma (1). The 7 non-neoplastic lesions (8%) histologically revealed tuberculosis (4), bronchopneumonia (2), and aspergillosis (1). Conclusions: Almost three fourths (71.6%) of the metastatic pulmonary resections comprised primaries from colorectum, breast and kidney. The interval between primary tumor and metastases ranged from zero months to 10 years (mean 2.5 years). Tuberculosis was the most common histologic diagnosis among the 8% of the non-neoplastic lesions, which were mistaken for metastatic carcinoma on clinical evaluation.

Changing patterns of Vibrio cholerae isolation over three consecutive cholera seasons (1992-1994) in east Delhi.

The emergence of new strains of Vibrio Cholerae has added a new dimension to the variability in pathogenicity and potential virulence of the organisms precipitating diarrhoeal diseases. Considering the shifting patterns of V. cholerae 01 there is a continuous need to monitor the strain characteristics. In this study total 541 stool specimens of acute secretory diarrhoea were investigated between May 1992 and November 1994 for strains of Vibrio Cholerae and anti-microbial susceptibility testing of all the confirmed V. Cholerae strains. In 1992, 50 of the 125 strains (40%) were positive for V. cholerae 01 predominantly biotype El Tor serotype ogawa, and 10 (80%) of non 01 type, with most strains susceptible to tetracycline (100%), chloramphenicol (98%) and Cotrimoxazole (98%), but all resistant to polymyxin B and furazolidine. In 1993, 44 (43.6%) of the 010 strains were positive for V. cholerae 0139 and the rest V. cholerae 01. In 1994, another sero group of V. cholerae 010 emerged, with 42 (13.3%) being positive. Isolates did not agglutinate with any of these antisera and have been labelled as 'other than non-01 vibrio cholerae'.

Characterisation of Vibrio cholerae 0139 isolated from diarrhoeal stools.

A total of 174 samples of acute diarrhoeal stools received over a period of seven months, yielded 101 isolated morphologically and biochemically resembling Vibro cholerae. Serologically, 57(56.4 per cent) of the 101 isolates were identified as V. cholerae 01 and remaining 44 (43.6 per cent) as V. cholerae 0139. Keeping in mind the unique potential of 0139 among non 01 vibrio to cause epidemics, we decided to undertake the study of biochemical characters and physiological behaviour of all the 44 V. cholerae 0139 isolates. All the stains were Voges Proskauer's test positive' haemagglutinating and grew in the presence of 6 per cent sodium chloride. 13 (29.5 per cent) strains showed haemolytic activity. Nine (20.5 per cent) were polymyxin-B sensitive and 4 (9.0 per cent) fermented lactose. All the isolates showed considerable degree of homogeneity in their biochemical and physiological properties, some characters define them to be closer to El Tor biotype.

Cluster of cases of clinical cholera due to Vibrio cholerae 010 in east Delhi.

A total of 514 samples of acute diarrhoeal stools received over a period of four months yielded 315 isolates morphologically and biochemically resembling V. cholerae. Out of 315 isolates, 223 (70.8%) were identified as V. cholerae 01, 20 (6.4%) as 0139 and 42 (13.3%) as 010. Thirty (9.5%) isolates did not agglutinate with any of the available antisera. All V. cholerae 010 isolates showed complete homogeneity in their biochemical and physiological properties. This strain appears to be closely related to El Tor biotype of V. cholerae 01, since it was positive for some of the tests used for identification of El Tor. The ability of strain 010 to grow in the presence of 6 per cent salt provides it the status of an important environmental pathogen. Acquisition of some virulence genes from El Tor vibrios by this strain 010 appears to be one of the mechanisms involved in the emergence of this serogroup.