Genetic determinants of sex in placental mammals developed by the evolution of primordial autosomes into the male and female sex chromosomes. The Y chromosome determines maleness by the action of the gene SRY, which encodes a protein that initiates a sequence of events prompting the embryonic gonads to develop into testes. The X chromosome in the absence of a Y chromosome results in a female by permitting the conversion of the embryonic gonads into ovaries. We trace the historical progress that resulted in the discovery that one X chromosome in the female is randomly inactivated in early embryogenesis, accomplishing approximate equivalency of X chromosome gene dosage in both sexes. This event results in half of the somatic cells in a tissue containing proteins encoded by the genes of the maternal X chromosome and half having proteins encoded by the genes of the paternal X chromosome, on average, accounting for the phenotype of a female heterozygote with an X chromosome mutation. The hypothesis of X chromosome inactivation as a random event early in embryogenesis was first described as a result of studies of variegated coat color in female mice. Similar results were found in women using the X chromosome-linked gene, glucose-6-phosphate dehydrogenase, studied in red cells. The random inactivation of the X chromosome-bearing genes for isoenzyme types A and B of glucose-6-phosphate dehydrogenase was used to establish the clonal origin of neoplasms in informative women with leiomyomas. Behind these discoveries are the stories of the men and women scientists whose research enlightened these aspects of X chromosome function and their implication for medicine.
This manuscript is a survey of the halachic attitudes toward organ transplant procedures from a living donor which can be defined as life-saving procedures for the recipient or at least life-prolonging proce-dures. Three fundamental problems concerning the halachic aspects of such transplantation are dis-cussed in detail: the danger to the donor, donation under coercion, and the sale of organs and tissues. The terms “halacha” and “Jewish law” are defined in the introduction.
Pharmacogenomics is the study of an individual’s interaction with a specific drug based upon the genetic make-up of the individual. Pharmacogenomic testing can be a powerful tool in testing a drug’s potential efficacy and toxicity on an individual patient. For this tool to be used correctly, certain criteria have to be met. First and foremost is the strength of association between the genetic variation and the drug’s interaction. The predictiveness of pharmacogenomics for the individual patient must be factored in as well. If these criteria are not met, requiring pharmacogenomic testing is at best a waste of money and in some cases can endanger the patient’s life. Stent thrombosis is a serious and many times fatal outcome in a small minority of patients who have received drug-eluting stents. Here, we discuss a case in which the FDA issued a “boxed warning” about the use of the anti-clotting medication, clopidogrel, used to prevent stent thrombosis, the pharmacogenomic data available at the time the warning was issued, and the medical community’s response to the FDA’s warning. This article also discusses developments in the field of anti-clotting therapy since the FDA’s warning.
The evolution of production systems is tightly linked to the story of Toyota Motor Company (TMC) that has its roots around 1918. The term “lean” was coined in 1990 following the exploration of the Toyota model that led to the “transference” thesis sustaining the concept that manufacturing problems and technologies are universal problems faced by management and that these concepts can be emulated in non-Japanese enterprises.
Lean is a multi-faceted concept and requires organizations to exert effort along several dimensions simultaneously; some consider a successful implementation either achieving major strategic components of lean, implementing practices to support operational aspects, or providing evidence that the improvements are sustainable in the long term.
The article explores challenges and opportunities faced by organizations that intend incorporating lean management principles and presents the specific context of the healthcare industry. Finally, the concepts of “essential few” and customer value are illustrated through a simple example of process change following lean principles, which was implemented in a dental school in the United States.
Cardiovascular disease (CVD), associated with vascular atherosclerosis, is the major cause of death in Western societies. Current risk estimation tools, such as Framingham Risk Score (FRS), based on evaluation of multiple standard risk factors, are limited in assessment of individual risk. The majority (about 70%) of the general population is classified as low FRS where the individual risk for CVD is often underestimated but, on the other hand, cholesterol lowering with statin is often excessively administered. Adverse effects of statin therapy, such as muscle pain, affect a large proportion of the treated patients and have a significant influence on their quality of life.
Coronary artery calcification (CAC), as assessed by computed tomography, carotid artery intima-media thickness (CIMT), and especially presence of plaques as assessed by B-mode ultrasound are directly correlated with increased risk for cardiovascular events and provide accurate and relevant information for individual risk assessment. Absence of vascular pathology as assessed by these imaging methods has a very high negative predictive value and therefore could be used as a method to reduce significantly the number of subjects who, in our opinion, would not benefit from statins and only suffer from their side-effects.
In summary, we suggest that in very-low-risk subjects, with the exception of subjects with low FRS with a family history of coronary artery disease (CAD) at young age, if vascular imaging shows no CAC or normal CIMT without plaques, statin treatment need not be administered.
The Cox maze procedure developed originally in 1987 by Dr James Cox has evolved from a “cut and sew” surgical procedure, where the maze was applied using multiple surgical cuts, to an extensive use of surgical ablation technology where ablation lesions are placed with alternative energy sources (radiofrequency, cryothermy, microwave, and high-frequency ultrasound). Furthermore, the procedure has changed from a median sternotomy approach only to one that can be performed minimally invasively and robotically. The purpose of this paper is to review the current available technology for the ablation of atrial fibrillation as well as the different procedural approaches for the surgical ablation of atrial fibrillation.
The surgical repair of complex congenital heart defects frequently requires additional tissue in various forms, such as patches, conduits, and valves. These devices often require replacement over a patient’s lifetime because of degeneration, calcification, or lack of growth. The main new technologies in congenital cardiac surgery aim at, on the one hand, avoiding such reoperations and, on the other hand, improving long-term outcomes of devices used to repair or replace diseased structural malformations. These technologies are: 1) new patches: CorMatrix® patches made of decellularized porcine small intestinal submucosa extracellular matrix; 2) new devices: the Melody® valve (for percutaneous pulmonary valve implantation) and tissue-engineered valved conduits (either decellularized scaffolds or polymeric scaffolds); and 3) new emerging fields, such as antenatal corrective cardiac surgery or robotically assisted congenital cardiac surgical procedures. These new technologies for structural malformation surgery are still in their infancy but certainly present great promise for the future. But the translation of these emerging technologies to routine health care and public health policy will also largely depend on economic considerations, value judgments, and political factors.
The current review addresses contemporary technological answers toadvances in cardiac surgery performed on octogenarian patients, namely off-pump coronary artery bypass grafting (CABG), proximal anastomosis device, routine use of intraoperative epiaortic ultrasound, proximal anastomosis without clamping, transcatheter aortic valve implantation (TAVI), and brain protection during cardiac surgery.
Non-Hodgkin lymphoma (NHL) is one of the most common hematologic malignancies worldwide. The incidence of NHL has been rising for several decades; however, in the last 20 years, it reached a plateau. NHL incidence among males is significantly higher than in females. In addition to gender itself, gravidity has a protective role against NHL occurrence. Gender also matters in terms of NHL clinical characteristics. For example, female predominance was found in three extra-nodal sites (the breast, thyroid, and the respiratory system) occasionally involved in NHL. The diagnosis of NHL during pregnancy is associated with a unique clinical behavior. It is usually diagnosed in the second or third trimester and in advanced stage. Furthermore, the histological subtype is highly aggressive, and reproductive organ involvement is common. The reduced rate of NHL among females may be explained by direct effects of estrogens on lymphoma cell proliferation or by its effect on anti-tumor immune response. Gender has an important role in responsiveness to standard B cell NHL treatment. Among older adults, women benefited more from the addition of the anti-CD20 antibody rituximab to standard chemotherapy regimens. This phenomenon can be explained by the difference in clearance rate of rituximab that was found to be significantly lower among older females than older males. In mantle cell lymphoma, women receiving lenalidomide have higher rates of response. An understanding of the mechanisms responsible for gender-associated NHL differences will ultimately improve the clinical approach, allowing for a more accurate assessment of prognosis and patient-tailored treatment.
Genetic aberrations have become a dominant factor in the stratification of myeloid malignancies. Cytogenetic and a few mutation studies are the backbone of risk assessment models of myeloid malignancies which are a major consideration in clinical decisions, especially patient assignment for allogeneic stem cell transplantation. Progress in our understanding of the genetic basis of the pathogenesis of myeloid malignancies and the growing capabilities of mass sequencing may add new roles for the clinical usage of genetic data. A few recently identified mutations recognized to be associated with specific diseases or clinical scenarios may soon become part of the diagnostic criteria of such conditions. Mutational study may also advance our capabilities for a more efficient patient selection process, assigning the most effective therapy at the best timing for each patient. The clinical utility of genetic data is anticipated to advance further with the adoption of deep sequencing and next-generation sequence techniques. We herein suggest some future potential applications of sequential genetic data to identify pending deteriorations at time points which are the best for aggressive interventions such as allogeneic stem cell transplantation. Genetics is moving from being mostly a prognostic factor to become a multitasking decision support tool for hematologists. Physicians must pay attention to advances in molecular hematology as it will soon be accessible and influential for most of our patients.
