Viroids are tiny single-stranded circular RNA pathogens that infect plants. Viroids do not encode any proteins, yet cause an assortment of symptoms. The following review describes viroid classification, molecular biology and spread. The review also discusses viroid pathogenesis, host interactions and detection. The review concludes with a description of future prospects in viroid research.

Naturally occurring viral nanomaterials have gained popularity owing to their biocompatible and biodegradable nature. Plant virus nanoparticles (VNPs) can be used as nanocarriers for a number of biomedical applications. Plant VNPs are inexpensive to produce, safe to administer and efficacious as treatments. The following review describes how plant virus architecture facilitates the use of VNPs for imaging and a variety of therapeutic applications, with particular emphasis on cancer. Examples of plant viruses which have been engineered to carry drugs and diagnostic agents for specific types of cancer are provided. The drug delivery system in response to the internal conditions is known as stimuli response, recently becoming more applicable using plant viruses based VNPs. The review concludes with a perspective of the future of plant VNPs and plant virus-like particles (VLPs) in cancer research and therapy.

Background & Objective: Spontaneous pregnancy loss has always been the frustrating experience for the couples and concern clinician. Chromosomal abnormality in either of the parent is considered to be the one of the leading cause of recurrent spontaneous miscarriages. This study was designed to evaluate the possible chromosomal etiology of miscarriage and the subsequent intimacy of maternal or paternal genetic abnormality. Methods: This case-control study was conducted between January 2016 and October 2016 at a tertiary care hospital in Karachi. A total of thirty-two couples were selected who had suffered with recurrent spontaneous miscarriages (RSM). Using conventional cytogenetic technique karyotyping was performed on all of the subjects. For the control twenty couples were also selected with no history of pregnancy loss. All the karyotypes were recorded on the standard method. Data was analyzed through SPSS version 22. Results: Among thirty-two cases nine cases were found to have abnormal karyotype. In which sex chromosomal trisomy=02 (46,XY/47,XXY), marker chromosome=01 (47,XX,+mar), Robertsonian translocation=01 (45,XY,der,(14:21),(q10;q10)), reciprocal translocation=01 (46,XX,t(11;22)(q23;q11.2)), inversion=02 (46,XX,inv(9)(p11q13)) and minor structural abnormalities=02 (46,XX,15PS+) were found. Approximately equal ratio with 1:1.25 was observed among male and female carrier respectively. Non-significant difference was found between the ages of both carriers (p=0.34). Though a significant different value was calculated in the case of number of miscarriage (p=0.004*). Moreover, no significant association was found among spontaneous miscarriage (SM) and recurrent spontaneous miscarriage (RSM) with respect to maternal age (p= 0.157). Conclusion: In the recent study possible chromosomal abnormalities suggested the evaluation of the patient with the history of recurrent spontaneous miscarriage must include conventional cytogenetic. Moreover, probe development and extended investigation can ease the prognosis among pregnancy related complication. doi: https://doi.org/10.12669/pjms.35.5.678 How to cite this:Hanif MI, Khan A, Arif A, Shoeb E. Cytogenetic investigation of couples with recurrent spontaneous miscarriages. Pak J Med Sci. 2019;35(5):1422-1427. doi: https://doi.org/10.12669/pjms.35.5.678 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

The objectives of this study was the molecular identification of Leishmania species and evaluate the diagnostic yield of PCR in comparison to the direct microscopy. This study was conducted at Centre for Molecular Genetics, University of Karachi, from March 2007 - December 2011. Samples were taken by means of Saline Aspirate (SA) from 50 patients suspected of cutaneous leishmaniasis (CL) from Dermatology Department, Jinnah Post Graduate Medical College, Karachi, Pakistan from March 2007 - December 2008. Only four samples (8%) had microscopically positive results. Recovery of parasites in cultures was of 09 strains (18%). These strains were maintained in vitro for the purpose of diagnosis by PCR and vaccine preparation. Three strains were vanished due to bacterial contamination. The remaining 06 culture positive samples along with saline aspirate obtained from all 50 patients. Sore were confirmed for the presence of Leishmania species by PCR method. Electrophoresis pattern from each isolates were compared with reference strains for L. major (MRHO/IR/75/ER), L. tropica (MHOM/SU/74/K27) and L. infantum (MHOM/TN/80/IPTI). Hundred percent isolates subjected to PCR, were similar to L. major (MRHO/IR/75/ER) reference strain. All of these PCR products showed a single band of approximately 650bp representing Leishmania major specific Kinetoplast DNA (kDNA) sequences. This 650bp band was of same size as that of the standard identified Leishmania strain. In conclusion CL caused by L. major infection is prevalent in the Sindh province of Pakistan. This study also proves that PCR method is sensitive diagnostic test in comparison to the direct microscopy.