فصلنامه آزمایشگاه و تشخیص
پیاپی 29 (پاییز 1394)

Although, it is for several years (at least 15 years) that couples are tested for carrier state of thalassemia minor, there are still diagnostic problems due to vast genetic mutations. It is to mention that currently more than 200 different mutations that lead to &beta-thalassemia are known and in some cases the mutation is so mild that routine tests are not able to diagnose any abnormalities. These mild mutations are frequently diagnosed when a newborn with thalassemia intermedia or HbH disease is born. We have gathered diagnostic points and ideas for better diagnosis of carrier satates during the past 15 years. Cases of minor &beta-thalassemia with normal indices and normal HbA2, and also cases with thalassemic indices and normal HbA2 and also cases with normal indices and high HbA2 reflect genetic heterogenecity of thalassemia. It may be necessary to include determination of globin chain synthesis ratio in addition to routine CBC and HbA2 level for definite diagnosis of carrier states.

Chromoblastomycosis is a chronic infection of the skin and subcutaneous tissues caused by one of several dematiaceous fungi,which is distinguished by the unique finding of muriform”sclerotic bodies”on microscopic examination of material from lesions. It has a worldwide distribution but has been reported most frequently from tropical or subtropical locations.Particularly high incidence rates have been reported from Brazil,Madagascar, and Costa Rica, the causative organisms have been isolated from soil and decaying vegetation in these and other high prevalence areas. A recognized penetrating injury at the involved site has occasionally preceded the development of the chromoblastomycosis lesion. Person-to-person spread of chromoblastomycosis has not been documented. Lesions developemost commonly on the distal lower extremities, a location compatible with exposure of damaged skin to soil. The primary skin lesion is a small papule that gradually enlarges over weeks to months to form a superficial nosule with an irregular, friable surface. Lesions continue to evolve, often over many years, and at a given time may have morphologic features of one or more of five types of chromoblastomycosis lesions described by Carrion. Although the appearance and location of the skin lesions and the typically chronic history may be most suggestive of chromoblastomycosis, the differential diagnosiscan include tuberculosis, mycetoma, leprosy, blastomycosis, and cutaneous leishmaniasis.Examination of material from the lesionsis therefore necessary to make a definitive diagnosis in most cases, and culture should be performed to determine the causative agent.

The genus of Raoultella (formerly Klebsiella) is a member of the family Enterobactericeae. Similar to other members, Raoultella spp are Gram-negative, aerobic, oxidase-negative, catalase- positive, non_motile rods and are capsulated such as Klebsiella.For differentiation of Raoultella from Klebsiella, 16SrRNA is using recently compare to biochemical test and DNA–DNA hybridization tests which were used before. In 2001, based on the histamine-producing strains and gene analyses the genus of Klebsiella spp. were reclassified, and the genus Raoultella including R. ornithinolytica, R. planticola and R. terrigena was separated. This article is extracted from the web search and review of 31 papers. In these studies different algorithms for differentiation of Raoultella from Klebsiella were suggested which are summarized in the recent review. The clinical implications of these bacteria are uncertain, nonetheless, the correct identification of bacterial species is essential to guide an effective antimicrobial treatment and improve clinical care. It was identified from the previous reports that the potential risk factors including invasive medical procedures, trauma with potential soil contamination and background diseases are related to the Raoultella spp. infections.

Major Histocompatibility Complex (MHC) is part of genome which plays a essential role in immune response to protein antigens and located on the short arm of the six chromosome. In human beings, it named HLA. HLA is divided three areas based on its tissue distribution and function of its building that is including HLA class I (locus A, B and C), class II (DQ, DR and DP) and class III. The association between the genes of the HLA and many diseases such as Behçet disease, myasthenia gravis, multiple sclerosis, HIV, HTLV, malaria, Mucosal Leishmaniasis and Toxoplasma gondii has been known in epidemiologic and demographic studies. Understanding the specific HLA alleles associated with susceptibility or resistance to a disease can be effective in produce and development of drugs, identifying the populations at high risk or resistance to a disease as well as in planning and prevention.

The main goal of this article is answering the question that at what stage of the pulmonary tuberculosis the affected patients are identified and diagnosed.The result of such a study are critical as they help us with measuring out the success or failure of identifying patients and finding out different ways of conveying the tuberculosis disease in the society. The sputum specimens of 1046 patients referred from different parts of Tehran and other parts of Iran were examined in the Zarifi laboratory. These specimens were both directly examined by the Ziehl-Nielson method and also cultured in the Lowenstein-Johnson media. However, determining the stage of the disease requires direct smear of the samples. The results of the study are summarized as follows. 14% of patients were diagnosed at the stage 1, 36% of patients were diagnosed at the stage 2, 21% of patients were diagnosed at the stage 3 and finally 29% of patients were at the stage 4. Therefore, the key point here is the unfortunate fact that 50% of patients referred to laboratories are already at the advanced stages of 3 and 4.

Bacillus cereus is a Gram positive and spore- forming bacrerium that is widely distributed in the environment. This bacterium is a human opportunistic pathogen and can cause diarrhoeal and emetic types of food poisoning. The diarrhoeal illnesses can be caused by hemolysin BL (HBL) non-hemolytic (NHE) and cytotoxin K. Bacillus cereus is a spore- formingbacterium, and so could tolerate harsh environmental conditions such as lack of nutients and improper temperatures.