What is the nature of the problem?

This review concentrates on the natural history of the infection. The virology and epidemiology of the disease are covered elsewhere. There are a number of inherent difficulties in studying the outcome of HCV infection: the onset is often not recognized, it can be asymptomatic, the progression is slow and patients may have had treatment. However some insights in recent years have been made.     

What is the best treatment?

The treatment of hepatitis C is expensive, difficult and arduous from the patient's perspective. It is similarly difficult for the clinician to decide who and when to treat. If hepatitis C is viewed from the liver's perspective we need only treat those patients who will develop the complications of chronic liver disease within their lifetimes. If we take a more holistic approach, then we have to consider the implications of being a carrier of a potentially transmissible blood borne virus on the patient themselves, their relationships, their families and their sense of wellbeing. There is now evidence of the large impact HCV has on quality of life and we have to consider extra hepatic manifestations of hepatitis C infection, possibly including the syndrome of 'brain fog' recently described. An additional factor that has to be considered in the decision to treat is whether patients perceive hepatitis C as a significant problem for themselves. For some patients, who have chaotic live styles, it is extremely difficult to get them to access healthcare. To then undergo the rigors and tribulations of hepatitis C therapy that is posing no current problem is unlikely to succeed. However, failure to engage these patients with therapy will lead to a significant proportion of them presenting with serious complications of chronic liver disease, with its attendant mortality, morbidity and cost. Underlying all these considerations is the tension between the costs of therapy and the benefits of therapy. Good arguments can be made in terms of cost-effectiveness for treating patients with a high likelihood of progressing to chronic liver disease and its complications. These arguments become much less persuasive when all patients are concerned.     

What is the significance of the HPV epidemic?

Human papillomavirus (HPV) is the most common sexually transmitted infection. The incidence of this infection has been on the rise in recent times. It is estimated that approximately 6 million new HPV infections are acquired each year in the United States alone, and prevalence data suggest that as many as 24 million American adults--that is, 1 in 5--may be infected with HPV. Unfortunately, there is little public awareness and knowledge about the infection and its sequelae. It is well known that more than 90% of cases of anogenital warts are caused by HPV. HPV has been implicated in cancers of the cervix, vulva, vagina, penis, anus, and oropharynx. The virus is a necessary cause of cervical cancer. HPV DNA is detected in almost 100% of cases of cervical cancer. There have been major strides in recent years in the prevention of this infection and consequently, of diseases related to it. Vaccines are available and licensed in some countries. Two HPV vaccines are available: a quadrivalent (HPV types 6, 11, 16, and 18) vaccine and a bivalent (HPV types 16 and 18) vaccine. Both vaccines show a more than 90% protection against persistent HPV infection for up to 5 years after vaccination. The role of the vaccine in males is still controversial. The vaccination cost, however, is beyond the reach of many individuals in developing countries where 80% of cervical cancer cases of are found. Many countries in Africa are battling with HIV, malaria, tuberculosis, maternal mortality, and childhood illness. Nevertheless, with increased awareness, political will, and engagement by pharmaceutical countries, HPV vaccines may become affordable in these countries.     

What is inside the electrocardiograph?

The details of digital recording and computer processing of a 12-lead electrocardiogram (ECG) remain a source of confusion for many health care professionals. A better understanding of the design and performance tradeoffs inherent in the electrocardiograph design might lead to better quality in ECG recording and better interpretation in ECG reading. This paper serves as a tutorial from an engineering point of view to those who are new to the field of ECG and to those clinicians who want to gain a better understanding of the engineering tradeoffs involved. The problem arises when the benefit of various electrocardiograph features is widely understood while the cost or the tradeoffs are not equally well understood.An electrocardiograph is divided into 2 main components, the patient module for ECG signal acquisition and the remainder for ECG processing which holds the main processor, fast printer, and display. The low-level ECG signal from the body is amplified and converted to a digital signal for further computer processing. The Electrocardiogram is processed for display by user selectable filters to reduce various artifacts. A high-pass filter is used to attenuate the very low frequency baseline sway or wander. A low-pass filter attenuates the high-frequency muscle artifact and a notch filter attenuates interference from alternating current power. Although the target artifact is reduced in each case, the ECG signal is also distorted slightly by the applied filter. The low-pass filter attenuates high-frequency components of the ECG such as sharp R waves and a high-pass filter can cause ST segment distortion for instance. Good skin preparation and electrode placement reduce artifacts to eliminate the need for common usage of these filters.     

What is the dumping syndrome?

Digestive Diseases and Sciences -