Mohammad Faizan Zahid

Insight into the molecular pathophysiology of myelodysplastic syndromes: targets for novel therapy

Myelodysplastic syndromes (MDS) are clonal hematopoietic stem cell disorders characterized by abnormal cellular differentiation and maturation with variable progression to acute leukemia. Over the last decade, scientific discoveries have unraveled specific pathways involved in the complex pathophysiology of MDS. Prominent examples include aberrations in cytokines and their signaling pathways (such as tumor necrosis factor‐alpha, interferon‐gamma, SMAD proteins), mutations in genes encoding the RNA splicing machinery (SF3B1, SRSF2, ZRSR2, and U2AF1 genes), mutations in genes disrupting the epigenetic machinery (TET2, DNMT3A, DNMT3B, EZH2, ASXL1). In addition, abnormalities in regulatory T‐cell dynamics and atypical interactions between the bone marrow microenvironment, stroma and progenitor cells, and abnormal maintenance of telomeres are also notable contributors to the complex pathogenesis of MDS. These pathways represent potential targets for novel therapies. Specific therapies include drugs targeting aberrant DNA methylation and chromatin remodeling, modulating/activating the immune system to enhance tumor‐specific cellular immune responses and reduce anomalous cytokine signaling, and blocking abnormal interaction between hematopoietic progenitors and stromal cells.

Haploidentical Hematopoietic Stem Cell Transplantation: Expanding the Horizon for Hematologic Disorders

Despite the advent of targeted therapies and novel agents, allogeneic hematopoietic stem cell transplantation remains the only curative modality in the management of hematologic disorders. The necessity to find an HLA-matched related donor is a major obstacle that compromises the widespread application and development of this field. Matched unrelated donors and umbilical cord blood have emerged as alternative sources of donor stem cells; however, the cost of maintaining donor registries and cord blood banks is very high and even impractical in developing countries. Almost every patient has an HLA haploidentical relative in the family, meaning that haploidentical donors are potential sources of stem cells, especially in situations where cord blood or matched unrelated donors are not easily available. Due to the high rates of graft failure and graft-versus-host disease, haploidentical transplant was not considered a feasible option up until the late 20th century, when strategies such as “megadose stem cell infusions” and posttransplantation immunosuppression with cyclophosphamide showed the ability to overcome the HLA disparity barrier and significantly improve the rates of engraftment and reduce the incidence and severity of graft-versus-host disease. Newer technologies of graft manipulation have also yielded the same effects in addition to preserving the antileukemic cells in the donor graft.

Central nervous system prophylaxis in diffuse large B-cell lymphoma.

Central nervous system (CNS) involvement with diffuse large B‐cell lymphoma (DLBCL) is a relatively uncommon manifestation; with most cases of CNS involvement occuring during relapse after primary therapy. CNS dissemination typically occurs early in the disease course and is most likely present subclinically at the time of diagnosis in many patients who later relapse in the CNS. CNS relapse in these patients is associated with poor outcomes. Based on a CNS relapse rate of 5% in DLBCL and weighing the benefits against the toxicities, universal application of CNS prophylaxis is not justified. The introduction of rituximab has significantly reduced the incidence of CNS relapse in DLBCL. Different studies have employed other agents for CNS prophylaxis, such as intrathecal chemotherapy and high‐dose systemic agents with sufficient CNS penetration. If CNS prophylaxis is to be given, it should be preferably administered during primary chemotherapy. However, there is no strong evidence that supports any single approach for CNS prophylaxis. In this review, we outline different strategies of administering CNS prophylaxis in DLBCL patients reported in literature and discuss their advantages and drawbacks.

Does academic assessment system type affect levels of academic stress in medical students? A cross-sectional study from Pakistan

Introduction Stress among medical students induced by academic pressures is on the rise among the student population in Pakistan and other parts of the world. Our study examined the relationship between two different systems employed to assess academic performance and the levels of stress among students at two different medical schools in Karachi, Pakistan. Methods A sample consisting of 387 medical students enrolled in pre-clinical years was taken from two universities, one employing the semester examination system with grade point average (GPA) scores (a tiered system) and the other employing an annual examination system with only pass/fail grading. A pre-designed, self-administered questionnaire was distributed. Test anxiety levels were assessed by The Westside Test Anxiety Scale (WTAS). Overall stress was evaluated using the Perceived Stress Scale (PSS). Results There were 82 males and 301 females while four did not respond to the gender question. The mean age of the entire cohort was 19.7±1.0 years. A total of 98 participants were from the pass/fail assessment system while 289 were from the GPA system. There was a higher proportion of females in the GPA system (85% vs. 59%; p<0.01). Students in the pass/fail assessment system had a lower score on the WTAS (2.4±0.8 vs. 2.8±0.7; p=0.01) and the PSS (17.0±6.7 vs. 20.3±6.8; p<0.01), indicating lower levels of test anxiety and overall stress than in students enrolled in the GPA assessment system. More students in the pass/fail system were satisfied with their performance than those in the GPA system. Conclusion Based on the present study, we suggest governing bodies to revise and employ a uniform assessment system for all the medical colleges to improve student academic performance and at the same time reduce stress levels. Our results indicate that the pass/fail assessment system accomplishes these objectives.

Recurrent Salmonellosis in a Child with Complete IL-12Rβ1 Deficiency.

A 3 year old boy presented with fever, abdominal pain and cervical lymphadenopathy. He had previously been treated empirically with anti-tuberculous therapy twice, at age 9 months and 27 months, for peripheral lymphadenopathy. An older sibling died of suspected tuberculous meningitis. Mantoux test was normal. Bone marrow and lymph node biopsy ruled out lymphoma and absolute neutrophil and lymphocyte counts were normal. Blood and lymph node cultures were positive for Salmonella typhi. The childs symptoms resolved with IV ceftriaxone and he was discharged. Over the next 2 years, the child was admitted every 2-3 months for culture positive S. typhi bacteremia with complaints of fever, abdominal distention and dysentery. HIV workup was negative. A prolonged course of probenicid and high dose amoxicillin increased interval between episodes to 4-5 months only. Cholecystectomy was debated and deferred due to suspicion of immunodeficiency. Blood samples from patient and parents were sent to France for workup and IL-12Rβ1 deficiency was found. Parental counseling and subsequent patient management remained difficult in view of financial constraints and outstation residence of family. At age 7 years, the child presented with small bowel obstruction. He was managed conservatively with antibiotics, IV fluids and blood transfusions, but eventually succumbed to endotoxic shock. This case highlights the importance of considering IL-12Rβ1 deficiency in children with repeated salmonellosis, a diagnosis which precludes intensive and aggressive monitoring and management of the patient in scenarios where bone marrow transplants are not feasible.

Knowledge, Attitude, and Practices of Healthcare Personnel Regarding the Transmission of Pathogens via Fomites at a Tertiary Care Hospital in Karachi, Pakistan

Background. Fomites are objects that can become colonized and serve as vectors in the transmission of pathogenic microorganisms. Literature examining the knowledge of healthcare personnel about this method of spread of infection is lacking. We conducted a study to assess the knowledge, attitude, and practices of healthcare personnel across different areas of patient care regarding the spread of infections at a tertiary care hospital in Karachi, Pakistan. Methods. A descriptive, cross-sectional study was conducted among healthcare personnel using a self-administered questionnaire. The questionnaire contained sections pertaining to demographic details and knowledge, attitude, and practices regarding fomites and their role in the transmission of pathogens. Results. Three hundred and fifty-three participants completed the questionnaire: 168 were male and 185 were female. Laboratory coats, stethoscopes, and bedside curtains were most frequently identified as fomites by the participants. Medical students had significantly lower mean scores in the knowledge and attitude sections than consultant physicians, resident physicians, and nurses. Nurses scored higher than consultant physicians, resident physicians, and medical students regarding practices that minimize fomite-borne spread of infections. 95% of the participants scored above 50% on the knowledge component of the questionnaire, but only 32.3% scored above 50% in the practices section. Conclusions. Our results show a large gap between the knowledge about fomites acting as vectors in the spread of pathogens and practices done to minimize this spread. Possessing adequate knowledge is ineffectual until and unless it is translated into the proper application of infection control practices. Incorporating awareness sessions and exercises into curricula are a reasonable way to raise awareness regarding this subject.

Genomic imbalances in peripheral blood confirm the diagnosis of myelodysplastic syndrome in a patient presenting with non-immune hemolytic anemia

Myelodysplastic syndrome (MDS) is a clonal stem-cell disorder characterized by dyshematopoiesis. We report a patient who presented with cytopenias and microangiopathic hemolytic anemia. Chromosome microarray analysis (CMA), using single nucleotide polymorphism arrays, on peripheral blood revealed genomic imbalances indicative of MDS, which was confirmed by bone marrow examination. This report highlights the importance of suspecting MDS in patients with cytopenias and microangiopathic hemolytic anemia. CMA of peripheral blood may assist in the preliminary diagnosis of MDS, representing a comparatively less invasive diagnostic procedure and may aid bone marrow evaluation when an aspirate sample is insufficient for conventional cytogenetic analysis.

Dust mites in a routine clinical stool sample

We report a case of dust mite carriage in a 56-year-old gentleman. Dust mites eggs and larvae were found in a stool sample which was taken for a routine clinical examination. He was completely asymptomatic with no history of rash, airway disease or other allergic manifestations associated with dust mites. We noticed that the oval structure of mite eggs resembled helminth eggs and therefore may be misidentified during routine clinical analysis. As the patient was otherwise healthy, it was concluded that no rigorous antiparasitic therapy was necessary to eliminate dust mites from his system.

Therapy-related myeloid neoplasms - what have we learned so far?

Therapy-related myeloid neoplasms are neoplastic processes arising as a result of chemotherapy, radiation therapy, or a combination of these modalities given for a primary condition. The disease biology varies based on the etiology and treatment modalities patients receive for their primary condition. Topoisomerase II inhibitor therapy results in balanced translocations. Alkylating agents, characteristically, give rise to more complex karyotypes and mutations in p53. Other etiologies include radiation therapy, high-dose chemotherapy with autologous stem cell transplantation and telomere dysfunction. Poor-risk cytogenetic abnormalities are more prevalent than they are in de novo leukemias and the prognosis of these patients is uniformly dismal. Outcome varies according to cytogenetic risk group. Treatment recommendations should be based on performance status and karyotype. An in-depth understanding of risk factors that lead to the development of therapy-related myeloid neoplasms would help developing risk-adapted treatment protocols and monitoring patients after treatment for the primary condition, translating into reduced incidence, early detection and timely treatment.

Health-Related Anxiety and Hypochondriacal Concerns in Medical Students: A Cross-Sectional Study From Pakistan

ABSTRACT Phenomenon: Transient health-related anxiety/hypochondriacal concerns in medical students are well documented. The literature suggests that after studying a particular disease, medical students are likely to consider any symptoms earlier regarded as normal to be signs of the disease they are studying. The aim of this study was to investigate the prevalence of these phenomena and their cognitive and distress aspects among medicals students in Karachi, Pakistan. Approach: This was an analytical, cross-sectional study. Self-administered questionnaires comprising demographic details, the Short Health Anxiety Inventory, Medical Students’ Disease (MSD) Perception Scale, and MSD Distress Scale were distributed to 1st- through 5th-year medical students. Findings: In total, 513 medical students (66% female) participated. Their mean age was 21 ± 1.6 years. Three hundred seventy-five students (73%) reported having visited a doctor at least once in the past 6 months. Fifty students (9.9%) admitted to having addictions. The overall prevalence of significant hypochondriacal concerns was 11.9% (61 students). The presence of addiction was associated with a greater likelihood of developing significant health-related anxiety (odds ratio = 3.82, p = .003), 95% confidence interval [1.51, 7.11]. Age, gender, medical school, year of medical school, and visits to the doctor in the previous 6 months were not associated with greater likelihood of developing significant health-related anxiety. Second-year medical students experienced a significantly greater degree of worry (MSD–Distress scale) than 5th-year students (M score = 12.6 ± 4.6 vs. 10.7 ± 4.4, p = .04). Insights: The prevalence of substantial hypochondriacal concerns in medical students in Pakistan was low in comparison to similar studies published in literature. Student health physicians should be aware of the true prevalence of hypochondriacal concerns and behavior and not dismiss legitimate complaints. Educational sessions to counteract this phenomenon can be incorporated into the curriculum of undergraduate medicine. By defining heightened awareness of symptoms as a normal process, different coping techniques can be discussed to help medical students reduce their level of stress.