Oxygen levels show varying effects on test results of SMBG

In the self-monitoring of blood glucose for patients with diabetes, the extent of partial pressure of oxygen’s influence on blood glucose measurements appears to differ among glucose oxidase systems, according to recent findings.

In the study, researchers obtained blood samples from 16 participants, selected regardless of diabetes status or diabetes type. The study population consisted of eight women and eight men (mean age, 52 years). Three of the patients had type 1 diabetes, four had type 2 diabetes and nine did not have diabetes.

The blood samples were analyzed using five electrochemical glucose oxidase systems and one electrochemical glucose dehydrogenase system. The blood samples were modified to various different partial pressure of oxygen (pO₂) levels to analyze the effect of different pO₂ levels on blood glucose test results. Portions of each sample were modified to three pO₂ levels: ≤45mm Hg, roughly 70mm Hg and ≥150mmHg. Each system was used to take five successive measurements on each sample, using the same test strip lot.

The pO₂ of the blood samples was ascertained immediately before and after measurement with the SMBG systems to ensure blood glucose consistency in the samples.

Descriptive statistics were utilized to evaluate the effects of pO₂ levels on systems’ measurement results. The investigators calculated the relative differences between the mean blood glucose levels at a pO₂ value of roughly 70 mm Hg, which was considered comparable to pO₂ levels in capillary blood samples. Mean blood glucose levels for the other pO₂ level categories also were calculated.

The researchers found that the glucose oxidase systems demonstrated mean relative variations between 11.8% and 44.5% at pO₂ values ≤45mm Hg and between –14.6% and –21.2% at pO₂ values ≥150mm Hg. The glucose dehydrogenase system showed a mean relative difference of –0.3% at pO₂levels ≤45mm Hg and –0.2% at pO₂ levels ≥150mm Hg.

According to the researchers, these discrepancies in oxygen-sensitive glucose oxidase systems, particularly at decreased pO₂ levels, may warrant updates in consumer transparency.

“To ensure an adequate use of oxygen-sensitive systems in daily life conditions of patients with diabetes, the pO2 range in which the systems operate well should be investigated further, and should be provided in the product information,” the researchers wrote.

Tomado de: healio.com

Schmid C. Diabetes Technol Ther. 2014;doi:10.1089/dia.2013.0184.

Researchers Report Treatment Clears HIV in Second Baby

Evidence is increasing that treating HIV-positive babies within a few hours of birth can dramatically restrict -- and perhaps eliminate -- infection, a researcher said here.

After nearly 2 years off anti-HIV therapy, the so-called Mississippi baby -- now 41 months old -- remains free of HIV, according to Deborah Persaud, MD, of Johns Hopkins University.

Sensitive tests can find no sign of HIV viremia or replication-competent virus in the child, Persaud said at the annual Conference on Retroviruses and Opportunistic Infections.

The first reports of the case were met with "skepticism and optimism," Persaud told reporters, but they prompted physicians in Los Angeles County to initiate very early treatment for a child born there to an HIV-positive mother.

The baby, born at Long Beach's Miller Children's Hospital, was given triple drug HIV therapy starting within 4 hours of birth to a mother with untreated HIV.

Tests at birth showed the presence of HIV DNA in the baby and testing 36 hours later -- 32 hours after treatment was started -- showed a plasma viral load of 217 copies per milliliter. A spinal tap when the child was 6 days old showed 32 copies of HIV RNA per milliliter of cerebrospinal fluid, Persaud reported.

But within days, almost all signs of HIV had disappeared. The plasma viral load, for instance, was and has remained undetectable, defined as fewer than 20 copies per milliliter.

Importantly, Persaud said, there is no indication that the child harbors a reservoir of "replication-competent virus" even if fragments of HIV RNA or DNA are present.

The child -- unlike the Mississippi baby -- has been kept on therapy, so investigators can draw no conclusions about whether the virus has been beaten permanently, Persaud said.

She told MedPage Today that there are no immediate plans to interrupt treatment for the Long Beach child, although her care team has initiated "conversations" about the issue with their institutional review board.

If there is "some consensus" that the anti-HIV medications should be stopped, it would happen when the child reaches age 2, she said. In the Mississippi case, the stoppage was inadvertent, after the child was lost to follow-up.

The two cases are a "signal that giving very early treatment to neonates really restricts HIV spread to the point where it is difficult to detect infection," she said.

Persaud added that plans are underway for a prospective international clinical trial involving 54 infants who will be treated at birth or very soon after, with planned treatment interruptions at age 2.

The report is an additional signal that very early treatment might interrupt the "seeding" of the HIV reservoir, commented Elaine Abrams, MD, of Columbia University in New York City, who was not part of the study but who moderated a press conference at which some details were reported.

"How limiting the reservoir will relate to remission and cure is still to be tested," she toldMedPage Today. "What happens when this kid stops drugs -- and I suspect they eventually will -- will be interesting to see."

Abrams noted that other studies have shown that starting therapy at 6 to 12 weeks of age is too late. "When you stop therapy at 2 years later, you get virus," she said.

Tomado de: medpagetoday.com 

By Michael Smith,

El orégano, eficaz contra el norovirus

En el futuro, es posible que el orégano pueda tener un papel importante en la lucha contra las enfermedades gastrointestinales causadas por el norovirus. El responsable es el carvacrol, que no solo da a esta especia su sabor y olor típicos, sino que además ha demostrado poseer propiedades antivíricas. Este descubrimiento ha sido realizado por un grupo de investigadores estadounidenses y publicado en la revista Journal of Applied Microbiology.

Investigadores de la Universidad de Arizona, EE. UU., han llevado a cabo la investigación con la forma murina del norovirus, la variante más parecida a la forma humana, resistente a los antimicrobianos y desinfectantes.

En los ensayos se ha observado que el carvacrol actúa directamente en las proteínas de la cápside y degrada la capa que recubre el virus. Esto posibilita que las sustancias antimicrobianas entren en la parte interna del virus y lo maten. Los investigadores creen que el modo en el que actúa el carvacrol hace improbables posteriores resistencias. Además, el carvacrol es seguro y no produce ningún subproducto nocivo.

«El carvacrol podría utilizarse como desinfectante alimentario y, posiblemente, como desinfectante de superficies, en particular junto con otros antimicrobianos », afirmó la autora principal Kelly Bright. Podría usarse en ámbitos en los que el empleo de sustancias agresivas puede ser problemático, como colegios, residencias, hospitales, guarderías y centros de rehabilitación

Tomado de Univadis.mx

Fuente principal: Gilling, D.H., Kitajima, M., Torrey, J.R. and Bright, K.R. (2014), Antiviral efficacy and mechanisms of action of oregano essential oil and its primary component carvacrol against murine norovirus. Journal of Applied Microbiology. doi: 10.1111/jam.12453