UNDERSTANDING HIV/AIDS: Overview and Life Cycle !

What is HIV/AIDS?

HIV stands for human immunodeficiency virus, which is the virus that causes HIV infection. The abbreviation “HIV” can refer to the virus or to HIV infection.

AIDS stands for acquired immunodeficiency syndrome. AIDS is the most advanced stage of HIV infection.

HIV attacks and destroys the infection-fighting CD4 cells of the immune system. The loss of CD4 cells makes it difficult for the body to fight infections and certain cancers. Without treatment, HIV can gradually destroy the immune system and advance to AIDS.

How is HIV spread?

HIV is spread through contact with certain body fluids from a person with HIV. These body fluids include:

• Blood
• Semen
• Pre-seminal fluid
• Vaginal fluids
• Rectal fluids
• Breast milk

The spread of HIV from person to person is called HIV transmission. The spread of HIV from a woman with HIV to her child during pregnancy, childbirth, or breastfeeding is called mother-to-child transmission of HIV.

In the United States, HIV is spread mainly by having sex with or sharing drug injection equipment with someone who has HIV. To reduce your risk of HIV infection, use condoms correctly and consistently during sex, limit your number of sexual partners, and never share drug injection equipment. 

Mother-to-child transmission is the most common way that children become infected with HIV. HIV medicines, given to women with HIV during pregnancy and childbirth and to their babies after birth, reduce the risk of mother-to-child transmission of HIV. 

You can’t get HIV by shaking hands or hugging a person who has HIV. You also can’t get HIV from contact with objects such as dishes, toilet seats, or doorknobs used by a person with HIV. HIV does not spread through the air or through mosquito, tick, or other insect bites.

The HIV Life Cycle

HIV attacks and destroys the CD4 cells of the immune system. CD4 cells are a type of white blood cell that play a major role in protecting the body from infection. HIV uses the machinery of the CD4 cells to multiply (make copies of itself) and spread throughout the body. This process, which is carried out in seven steps or stages, is called the HIV life cycle.

What is the connection between the HIV life cycle and HIV medicines?

Antiretroviral therapy (ART) is the use of HIV medicines to treat HIV infection. HIV medicines protect the immune system by blocking HIV at different stages of the HIV life cycle.

HIV medicines are grouped into different drug classes according to how they fight HIV. Each class of drugs is designed to target a specific step in the HIV life cycle.

ART combines HIV medicines from at least two different HIV drug classes, making it very effective at preventing HIV from multiplying. Having less HIV in the body protects the immune system and prevents HIV from advancing to AIDS. ART also reduces the risk of HIV drug resistance.

ART can’t cure HIV, but HIV medicines help people with HIV live longer, healthier lives. HIV medicines also reduce the risk of HIV transmission (the spread of HIV to others).

What are the seven stages of the HIV life cycle?

The seven stages of the HIV life cycle are: 1) binding, 2) fusion, 3) reverse transcription, 4) integration, 5) replication, 6) assembly, and 7) budding. To understand each stage in the HIV life cycle, it helps to first imagine what HIV looks like.

Now follow each stage in the HIV life cycle, as HIV attacks a CD4 cell and uses the machinery of the cell to multiply.

Read more: HIV Overview

Video: The Life Cycle of HIV

This video explains how HIV targets human immune cells, and uses immune cell machinery to make copies of itself. By comparing an analogy to the life cycle of HIV, this presentation will help you understand how HIV systematically reduces immunity within the body.

Source: YouTube

Heterogeneity in Tuberculosis.

Infection with Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), results in a range of clinical presentations in humans. Most infections manifest as a clinically asymptomatic, contained state that is termed latent TB infection (LTBI); a smaller subset of infected individuals present with symptomatic, active TB. Within these two seemingly binary states, there is a spectrum of host outcomes that have varying symptoms, microbiologies, immune responses and pathologies. Recently, it has become apparent that there is diversity of infection even within a single individual. A good understanding of the heterogeneity that is intrinsic to TB — at both the population level and the individual level — is crucial to inform the development of intervention strategies that account for and target the unique, complex and independent nature of the local host–pathogen interactions that occur in this infection. In this Review, we draw on model systems and human data to discuss multiple facets of TB biology and their relationship to the overall heterogeneity observed in the human disease.

Read more: Heterogeneity in Tuberculosis.

Figure 1: A classical tuberculosis granuloma. The hallmark tuberculosis
granuloma is a highly organized collection of immune cells that aggregate
around a central necrotic core.

Source: NATURE REVIEWS IMMUNOLOGY

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Association Between Genetic Variation And Influenza Severity.

It is estimated that in the USA influenza -related deaths in recent years have ranged from 12,000 to 56,000. Factors like age, obesity, pregnancy and such chronic health conditions as asthma, chronic lung disease and heart disease are associated with an elevated risk of complications and death.

However, there are no proven genetic markers of influenza risk with an established mechanism of action. Interferon Induced Transmembrane Protein 3 (IFITM3) is an anti-viral protein that helps to block influenza infection of lung cells and to promote survival of the killer T cells that help clear the infection in the airways.

Image: A scanning electron micrograph of a CD8+ T cell engaging a virus.

(Photo courtesy of Dennis Kunkel).

A group of scientists collaborating with those at St. Jude Children's Research Hospital (Memphis, TN, USA) searched for other possible IFITM3 variants that correlated with gene expression, levels of the IFITM3 proteins and were common in influenza patients in the USA. The search led to an IFITM3 variant known as rs34481144. They checked 86 children and adults in Memphis with confirmed influenza infections and found two-thirds of patients with the most severe symptoms carried at least one copy of the newly identified high-risk IFITM3 variant. The high-risk variant was found in just 32% of patients with milder symptoms.

The team also found an association between the newly identified high-risk variant and severe and fatal influenza infections in 265 critically ill pediatric patients hospitalized in one of 31 intensive care units nationwide. The patients did not have health problems that put them at high risk for severe influenza. Of the 17 patients in this group who died from the infection, 14 carried at least one copy of the newly identified high-risk variant. Further study revealed how binding differed between the high-risk and protective variants. Those differences led to lower levels of the IFITM3 protein in individuals with two copies of the high-risk gene variant compared to other patients. The Memphis influenza patients also had fewer of the killer T cells in their upper airways. The study identifies a new regulator of IFITM3 expression that associates with CD8+ T cell levels in the airways and a spectrum of clinical outcomes.

Paul Thomas, PhD, an immunologist and corresponding author of the study, said, “A genetic marker of influenza risk could make a life-saving difference, particularly during severe influenza outbreaks, by helping prioritize high-risk patients for vaccination, drug therapy and other interventions. These results raise hopes that this newly identified IFITM3 variant might provide such a marker.” The study was published on July 17, 2017, in the journal Nature Medicine.

Source: labmedica

Antibiotics In Early Life Could Raise Children's Food Allergy Risk

Infection in the first year of life can be deadly for an infant, and antibiotic treatment is often the first port of call. But such treatment may have a downside; new research from the University of South Carolina finds early antibiotic exposure could raise a child's risk of food allergies.

While the study did not investigate the reasons behind this association, the researchers say it is likely down to changes in gut microbiota as a result of antibiotic treatment.

Lead author Dr. Bryan Love, of the Department of Clinical Pharmacy and Outcomes Sciences at the South Carolina College of Pharmacy, and colleagues report their results in the journal Allergy, Asthma & Clinical Immunology.

Previous research has suggested that changes to the composition of gut bacteria in early life can have negative implications for health, and antibiotics are known to do just that.

Read more: Antibiotics In Early Life Could Raise Children's Food Allergy Risk

Early antibiotic exposure could raise children's risk of food allergies.

Source: medicalnewstoday

Zika Virus — Reigniting The TORCH

The recent association between Zika virus (ZIKV) infection during pregnancy and fetal microcephaly has led to a renewed interest in the mechanisms by which vertically transmitted microorganisms reach the fetus and cause congenital disease. In this Opinion article, we provide an overview of the structure and cellular composition of the human placenta and of the mechanisms by which traditional 'TORCH' pathogens (Toxoplasma gondii, other, rubella virus, cytomegalovirus and herpes simplex virus) access the fetal compartment. Based on our current understanding of ZIKV pathogenesis and the developmental defects that are caused by fetal ZIKV infection, ZIKV should be considered a TORCH pathogen and future research and public health measures should be planned and implemented accordingly.

Zika virus (ZIKV), a member of the Flaviviridae family of RNA viruses, was first isolated in the Zika forest in Uganda in 1947.

Read more: Zika Virus — Reigniting The TORCH

Routes used by TORCH pathogens to overcome the placental barrier. Vertical
transmission and congenital disease induced by ZIKV.

Source: NatureReviewsMicrobiology

Download: Zika Virus — Reigniting The TORCH.pdf

The Common Cold and That Dreaded Flu Virus

Here it is again, the cold and flu season when we all head indoors to share our sneezes and viruses. It’s time to get serious about preventing illness, and that means caring for our personal air filter: the nose.

Viruses are the worst seasonal offenders, and colds are the most common virus we pass around. But the influenza virus is so much worse than a cold. Most folks do not really understand the difference between these two illnesses, yet the difference can be deadly.

Influenza, commonly called “the flu,” is caused by the influenza virus. This is a specific respiratory virus quite different than the cold virus. The entire respiratory tract—including the nose, throat, and lungs—becomes infected. The illness is severe and can be life-threatening; children, the elderly, and those who have underlying medical conditions are at greatest risk for complications.

Read more: The Common Cold and That Dreaded Flu Virus

Source: naturalsolutionsmag

All You Need to Know About Nephritis

To understand kidney problems such as nephritis, it's helpful to start with some background on what the kidneys are, and what they do.

The kidneys are two bean-shaped, fist-sized organs found just under the ribs on the left and right sides of the spine. They remove impurities and extra water from the blood, filtering 120-150 quarts of blood a day, according to the National Institute of Diabetes and Digestive and Kidney Diseases.

Each kidney consists of thousands of structures called nephrons, where the actual blood filtering takes place. In the nephron, a two-step cleaning process separates what the body needs to keep from what it can get rid of.

A filter called the glomerulus catches blood cells and protein, sending water and waste to a second filter, called a tubule. The tubule captures minerals. After that, what remains leaves the body as urine.

Read more: All You Need to Know About Nephritis

Nephritis can lead to kidney failure if not treated. There are various ways of preventing kidney damage
if someone has symptoms of nephritis. Monitoring blood pressure is important if kidney problems
develop.

Source: medicalnewstoday

Steam Inhalation Does not Ease Chronic Nasal Congestion

While steam inhalation is widely adopted in an attempt to ease a blocked nose, a new study suggests it is unlikely to work for chronic nasal congestion.

However, saline nasal irrigation - a technique used to "flush out" excess mucus from the nasal cavity - may be beneficial for chronic nasal congestion, according to the researchers.

Study leader Dr. Paul Little, professor of primary care research at the University of Southampton, United Kingdom, and colleagues recently published their findings in the Canadian Medical Association Journal.

Nasal congestion is a common complaint, often caused by the common cold, flu, or sinus infection. Hay fever and other allergies, nasal polyps, and chronic sinusitis are some other causes of the condition.

While nasal congestion is just an irritation for the most part, it can cause other symptoms, such as headaches and blurred vision.

Read more: Steam Inhalation Does not Ease Chronic Nasal Congestion

Despite its popularity, inhaling steam is unlikely to ease symptoms of chronic nasal congestion.

Source: medicalnewstoday

New Method Developed for Detecting Mycobacteria in the Lungs

A research team from the Institute of Medical Microbiology at the University of Zurich and the National Center for Mycobacteria has carried out a large-scale study with more than 6800 patient samples to examine molecular-based methods for the detection of mycobacterial pathogens. Because many mycobacteria only grow at a slow pace, routine detection using bacteria cultures in highly specialized and expensive high-safety labs takes several weeks to complete. The subsequent susceptibility test to determine the appropriate medicine also takes 1 to 2 weeks.

"For patients and doctors, this long waiting period is an unnecessary test of their patience", says Peter Keller, M.D., from the Institute of Medical Microbiology at the UZH. "By comparison, with molecular detection methods, most patients know after 1 or 2 days whether they have an infection with tuberculosis pathogens or with nontuberculous mycobacteria."

Mycobacteria cause various illnesses. Mycobacterium tuberculosis, the main representative of this genus, is the causative agent of tuberculosis, which killed around 1.5 million people worldwide in 2014.

Read more: New Method Developed for Detecting Mycobacteria in the Lungs

Mycobacterium tuberculosis in patient samples.

Source: genengnews

Disorders that can affect the placenta during pregnancy

The placenta and its health are vital to the health of a woman's pregnancy and fetal development. This organ provides oxygen, nutrients, and filters fetal waste during pregnancy.

It also plays an important role in hormone production and protects the fetus from bacteria and infections.

The blood-rich placenta is joined to the uterine wall and connects to the baby by way of the umbilical cord.

Most often the placenta attaches itself to the top or side of the uterine wall. At times, however, it may grow or attach to the uterus in a way that can cause health problems.

Read more: Disorders that can affect the placenta during pregnancy

The risk of placental disorders is affected by ethnicity, lifestyle and medical history.

Source: medicalnewstoday

Lymphoma

Overview

Lymphoma is cancer that begins in cells of the lymph system. The lymph system is part of the immune system, which helps the body fight infection and disease. Because lymph tissue is found all through the body, lymphoma can begin almost anywhere.

The two main types of lymphoma are Hodgkin lymphoma and non-Hodgkin lymphoma (NHL). These can occur in both children and adults.

Most people with Hodgkin lymphoma have the classic type. With this type, there are large, abnormal lymphocytes (a type of white blood cell) in the lymph nodes called Reed-Sternberg cells. Hodgkin lymphoma can usually be cured.

There are many different types of NHL that form from different types of white blood cells (B-cells, T-cells, NK cells). Most types of NHL form from B-cells. NHL may be indolent (slow-growing) or aggressive (fast-growing). The most common types of NHL in adults are diffuse large B-cell lymphoma, which is usually aggressive, and follicular lymphoma, which is usually indolent.

Read more: Lymphoma

Source: cancer.gov