Publications by authors named "Umit Y Malkan"

Article Synopsis
  • - Multicentric Castleman disease (MCD) is a rare and aggressive lymphoproliferative disorder often associated with human herpesvirus-8 (HHV-8) and Kaposi's sarcoma, typically seen in HIV-positive patients but also affecting an HIV-negative individual in this case.
  • - A 78-year-old man with multiple malignancies, including Kaposi's sarcoma and multiple myeloma, was found to have HHV-8 positive MCD and faced severe complications during treatment, resulting in his death shortly after receiving rituximab.
  • - The case underscores the complexities of diagnosing and treating MCD and its related cancers, indicating that outcomes are typically poor despite treatment efforts and highlighting the need for further
View Article and Find Full Text PDF

Lipotoxicity can mediate endothelial dysfunction in obesity. Altered endothelial cell phenotype during the pathobiological course of the lipotoxicity may lead to hemostatic abnormalities, which is a hallmark of several hematological disorders. Impaired hemostasis could also be directly related to numerous metabolic diseases such as hypertension, diabetes, and atherosclerosis.

View Article and Find Full Text PDF

Background/aim: The clinical presentation of pediatric coronavirus disease 2019 (COVID-19) is associated with a milder disease course than the adult COVID-19 syndrome. The disease course of COVID-19 has three clinicobiological phases: initiation, propagation, and complication. This study aimed to assess the pathobiological alterations affecting the distinct clinical courses of COVID-19 in pediatric age groups versus the adult population.

View Article and Find Full Text PDF
Article Synopsis
  • This study investigates a new drug called Si162, which targets Src, to improve treatment options for malignant melanoma, aiming for early detection and personalized medicine.
  • Researchers tested melanoma cells from patients to assess how effective Si162 is by determining its cytotoxicity and resistance genes.
  • The results identified 36 genes linked to sensitivity to Si162, highlighting significant differences in gene expression between resistant and sensitive melanoma cells, which could serve as potential biomarkers for treatment efficacy.
View Article and Find Full Text PDF

Background: Hairy cell leukemia (HCL) is a rare mature B-cell malignancy that is primarily treated with purine analogues. However, relapse remains a significant challenge, prompting the search for alternative therapies. The BRAF V600E mutation prevalent in HCL patients provides a target for treatment with vemurafenib.

View Article and Find Full Text PDF

Background: Tigecycline-associated hypofibrinogenemia has been reported as an important adverse effect in recent years, but controlled studies minimizing confounding factors are needed. The objective of our study was to assess changes in fibrinogen levels in patients for hospitalization, comparing two antibiotic episodes (tigecycline and other) within the same patients.

Methods: The retrospective, self-controlled case series study was conducted at our University Hospitals.

View Article and Find Full Text PDF

As in the case of cancer, the risk of infection increases when the host's immune system is not working properly. It has been shown that toxins produced by the bacteria responsible for bacterial infections can alter the properties of cancer cells as well as their sensitivity to chemotherapy agents. () is one of the most prevalent pathogens in acute myeloid leukemia (AML) patients and it produces several virulence factors, including Staphylococcal enterotoxin A (SEA) and Staphylococcal enterotoxin B (SEB).

View Article and Find Full Text PDF

Supplemental probiotics available without a doctor's prescription have become a booming global market in past few years. Medical research has shown that probiotics may benefit both healthy people and cancer patients by improving their immune systems and digestive health. Even though they seldom produce serious side effects, it's important to note that they are generally safe to use.

View Article and Find Full Text PDF

Introduction: Tyrosine kinase inhibitors (TKis) and Bruton's TKi (BTKis) constitute broadly used antitumor drug groups with almost completely tolerable and manageable side-effect profiles. Mainly side effects are cardiovascular and gastrointestinal for the TKi group. Hypophosphatemia is documented frequently in many studies with TKis but rarely mentioned with ibrutinib use up to the present.

View Article and Find Full Text PDF

Background: Since well-designed prospective comparative trials are lacking, haploidentical hematopoietic stem cell transplantations approach should be based on the expertise of a particular center. In this study, we aimed to report the results and outcomes of patients who underwent haploidentical hematopoietic stem cell transplantation.

Methods: : Thirty-nine patients who underwent transplantation in our clinic between 2015 and 2022 were retrospectively analyzed.

View Article and Find Full Text PDF

The SARS-CoV-2 spike protein mRNA-based vaccines have prevented countless mortality and morbidity, and have an excellent risk/benefit ratio. However, various adverse events may rarely occur after the BNT162b2 vaccine, like any other medical intervention. The COVID-19 itself and the spike protein produced endogenously by mRNA vaccines may have immunological, microenvironmental, prothrombotic, and neoplastic effects.

View Article and Find Full Text PDF

Acute myeloid leukemia (AML) is the most heterogeneous hematological disorder and blast cells need to fight against immune system. Natural killer (NK) cells can elicit fast anti-tumor responses in response to surface receptors of tumor cells. NK-cell activity is often impaired in the disease, and there is a risk of insufficient tumor suppression and progression.

View Article and Find Full Text PDF

Background: Thrombocytopenia is a common complication following hematopoietic stem cell transplantation (HSCT). Eltrombopag has been used in thrombocytopenia treatment after HSCT in recent years. Herein, we present our experience of 25 patients treated with eltrombopag for post-HSCT thrombocytopenia.

View Article and Find Full Text PDF

Patients with isolated leukopenia pose difficulties in diagnosis because there is no related guideline in the literature. In this study, our aim was to evaluate the clinical and laboratory associations of isolated, nonspecific (not related to neutropenia) leukopenia. In this retrospective data review study, patients who were admitted to Hacettepe University Hematology Outpatient Clinic between 2014 and 2019 due to leukopenia were evaluated.

View Article and Find Full Text PDF

Materials And Methods: Up to June 2022, literature searches were performed using the internet search engines Medline, Google Scholar, and Embase: Ankaferd. PRISMA flow diagram described the Ankaferd search.

Results: ABS have important effects in several cellular processes, like control of the cell cycle, apoptosis, angiogenesis, signal transduction, inflammation, immunologic, and metabolic mechanisms.

View Article and Find Full Text PDF

Objective: Studies comparing the efficacy and safety of prophylactic regimens for central nervous system (CNS) involvement in acute lymphoblastic leukemia (ALL) are scarce in adults. This multicenter retrospective study aimed to compare the efficacy of prophylactic regimens with and without CNS irradiation on the development of CNS relapse during follow-up.

Materials And Methods: This was a multicenter comparative cohort study.

View Article and Find Full Text PDF

Despite mass vaccination, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine-induced subacute thyroiditis (SAT) is rarely seen as a complication. The reason why some individuals are susceptible to developing vaccine-induced SAT is not known. SAT develops in genetically predisposed individuals who carry specific human leukocyte antigen (HLA) haplotypes.

View Article and Find Full Text PDF

Background/aim: The disease caused by SARS-CoV-2 was named as COVID-19. There is as yet insufficient information about the effects of HSCT on the clinical course of COVID-19. In the present study, we aimed to investigate the clinical course of COVID-19 in patients who had undergone HSCT.

View Article and Find Full Text PDF

Introduction: All-trans retinoic acid (ATRA) is a physiological metabolite of vitamin A and it is used for the treatment of acute promyelocytic leukemia (APL). Hypercalcemia is a rare side effect of ATRA and it may be potentiated after interaction of ATRA with azole group antifungals. Herein, we have reported an APL case with hypercalcemia that is caused by the interaction of ATRA and posaconazole.

View Article and Find Full Text PDF

Background/aim: COVID-19 syndrome due to the SARS-CoV-2 virus is a currently challenging situation ongoing worldwide. Since the current pandemic of the SARS-CoV-2 virus is a great concern for everybody in the World, the frequently asked question is how and when the COVID-19 process will be concluded. The aim of this paper is to propose hypotheses in order to answer this essential question.

View Article and Find Full Text PDF

Background: Autologous stem cell transplantation (ASCT) is one of the standard treatments of choice for eligible multiple myeloma (MM) patients. Herein, we aimed to analyze MM patients at our center and compare the clinical outcomes of single and double ASCT patients.

Materials And Methods: Patients who were diagnosed as having MM and had undergone single or double ASCT in our clinic between the years 2003 and 2020 were retrospectively examined.

View Article and Find Full Text PDF

Microangiopathic hemolytic anemia (MAHA) can be observed as a paraneoplastic syndrome (PS) in certain tumors. MAHA-related signet ring cell carcinoma (SRCC) of an unknown origin is very infrequent. Herein we present a SRCC case presented with refractory acquired thrombotic thrombocytopenic purpura (TTP).

View Article and Find Full Text PDF

Despite the availability of various treatment protocols, response to therapy in patients with Acute Myeloid Leukemia (AML) remains largely unpredictable. Transcriptomic profiling studies have thus far revealed the presence of molecular subtypes of AML that are not accounted for by standard clinical parameters or by routinely used biomarkers. Such molecular subtypes of AML are predicted to vary in response to chemotherapy or targeted therapy.

View Article and Find Full Text PDF

Background/aim: Graft-versus-host disease (GVHD) is a crucial complication leading to significant morbidity and mortality allogeneic hematopoietic stem cell transplantation which occurs in approximately half of the transplant recipients. Suppression of tumorigenicity 2 (ST2) and regenerating islet-derived 3-alpha(Reg3a) might be important biomarkers to predict acute GVHD.

Materials And Methods: In the present study, blood samples were collected from 17 patients with acute GVHD and 12 control patients after allogeneic stem cell transplantation.

View Article and Find Full Text PDF