They have some real results with the oral chelator .. hydroxyurea .. and sooo again gives evidence of the iron PREceding the anemia .. ?
Oral liquid hydroxyurea promising for long-term use in babies with
sickle cell anemia
17 Jun 2005
Treating babies who have sickle cell anemia (SCA) with oral liquid
hydroxyurea appears to prevent the onset of long-term complications
triggered by this disease, according to results of a preliminary study
by investigators at St. Jude Children's Research Hospital.
The study's findings are important because the onset of damage caused
by SCA complications can occur as early as three months after birth.
Starting treatment before those complications begin could dramatically
reduce the chance of organ damage and premature death. A report on the
study appears in the June 14 online edition of Blood.
In SCA, a genetic mutation causes oxygen-carrying protein hemoglobin
(Hb) to form rigid cords in red blood cells, causing the cells to take
on a bent, sickled shape. The sickled cells clog small blood vessels,
causing pain and serious damage to the brain, kidneys, spleen and other
organs; and the subsequent premature death of the abnormal red cells
causes anemia. In the United States, SCA is found mostly among African
Americans.
Hydroxyurea increases the production of fetal hemoglobin (HbF), the
main oxygen transport protein in fetal red blood cells. Because HbF
prevents red blood cells from "sickling," clinicians have used
hydroxyurea for about a decade to reactivate HbF production in adults
and older children with SCA. In addition, hydroxyurea reduces the
severity of symptoms suffered by adolescents and adults with SCA, such
as lung infections, organ damage, stunted growth, impaired brain
development and acute chest syndrome (ACS). ACS refers to an infection
in the lungs that causes difficulty breathing, pain and other symptoms
and can be fatal.
The current St. Jude study was an extension of a previous clinical
trial, Hydroxyurea Safety and Organ Toxicity (HUSOFT), which was the
first in which young babies were treated with hydroxyurea. The original
HUSOFT study, published in 2001, demonstrated that short-term oral
liquid hydroxyurea therapy can be safe and effective in babies with
SCA. In the extension study, these infants were followed for up to six
years of therapy.
"Our results are promising and justify a larger multicenter clinical
trial to confirm that treating babies with hydroxyurea is safe and
effective," said Jane S. Hankins, M.D., a physician at the St. Jude
Comprehensive Sickle Cell Center and the study's lead author. "If a
larger trial supports our observations in the HUSOFT Extension, the
treatment of sickle cell anemia will undergo a significant change."
"This study is particularly encouraging because it suggests that we
can treat babies with hydroxyurea for several years without side
effects serious enough to limit the use of this drug," said Winfred
Wang, M.D., St. Jude Comprehensive Sickle Cell Center director. "Our
aim is to make sickle cell anemia a survivable disease that doesn't
significantly reduce a person's quality of life." Wang is the senior
author of the paper in Blood.
A two-year pilot study of 21 babies with SCA, the original HUSOFT was
designed to examine the feasibility of treating infants with liquid
hydroxyurea; to determine the toxicity of this drug in babies; to
assess hydroxyurea's effects on fetal Hb levels; and to observe if this
treatment could preserve spleen function. Patients received 20
milligrams/kilgrams of body weight/day (mg/kg/day) of hydroxyurea. All
21 patients who completed the initial study were enrolled by their
parents into the HUSOFT Extension study. In that study, the dose of
hydroxyurea was elevated from 20 to 30 mg/kg/day for an average of 4.0
years (range 2.1 - 6.0 years).
The aim of the HUSOFT Extension was to determine if this higher dose,
given for an extended period of time, provided significant long-term
benefits without causing unacceptable side effects in children ranging
in age from 2.6 to 4.4 years (median age 3.4 years).
After four years of hydroxyurea therapy, the concentrations of Hb, HbF
and the volume of red blood cells were significantly increased in the
children receiving hydroxyurea. Moreover, the HbF level often exceeded
20 percent of the total amount of Hb, Hankins said. "In children who
weren't treated with hydroxyurea, the level of HbF declined
significantly," she added. "The fact that HbF levels rose in babies
treated with hydroxyurea suggests that the drug is effective in babies,
as well as in adolescents and adults."
Babies receiving hydroxyurea also weighed more and were taller than
those untreated children 2 to 5 years old who had been observed in a
previous, long-term national study called the Cooperative Study for
Sickle Cell Disease. The average weight gain for babies in the St. Jude
study was more than 4.5 pounds per year; and the gain in height was
more than 3 inches, the researchers report.
"Hydroxyurea could also prove to be an effective way to improve the
care of sickle cell anemia patients who live in underprivileged areas
of the world," said Russell E. Ware, M.D., Ph.D., director of the
Hematology division of the Department of Hematology-Oncology at St.
Jude. "Treatment with hydroxyurea requires periodic checkups, but the
medication is relatively inexpensive and should be adaptable to
countries with limited resources," he said. Ware is a co-author of
the paper.
Other authors of the article include Zora Rogers (University of Texas,
Dallas); Lynn W. Wynn, MSN, PNP, CCRP (St. Jude); Peter A. Lane (Emory
University, Atlanta, GA); and J. Paul Scott (Medical College of
Wisconsin, Milwaukee).
This work was supported in part by a General Clinical Research Center
grant and ALSAC.
St. Jude Children's Research Hospital
St. Jude Children's Research Hospital is internationally recognized for
its pioneering work in finding cures and saving children with cancer
and other catastrophic diseases. Founded by late entertainer Danny
Thomas and based in Memphis, Tenn., St. Jude freely shares its
discoveries with scientific and medical communities around the world.
No family ever pays for treatments not covered by insurance, and
families without insurance are never asked to pay. St. Jude is
financially supported by ALSAC, its fund-raising organization. For more
information, please visit
http://www.stjude.org.
Contact: Carrie Strehlau
carrie.streh...@stjude.org
901-495-2295
Marc Kusinitz, Ph.D.
marc.kusin...@stjude.org
901-495-5020
St. Jude Children's Research Hospital
http://www.stjude.org --------------------------------------------------------------------------------
Prevention of sickle cell crises with multiple phlebotomies.
Bouchair N, Manigne P, Kanfer A, Raphalen P, de Montalembert M, Hagege
I, Verschuur A, Maier-Redelsperger M, Girot R
Service de pediatrie, CHU,
Constantine, Algerie.
OBJECTIVES:
Sickle cell disease patients suffering from frequent painful crises
were submitted to phlebotomies in order to reduce hospitalization days
due to pain, through hemoglobin (Hb) level reduction and iron
deficiency in patients with an hemoglobin level equal to or above 9.5
g/dL.
PATIENTS:
Seven sickle cell disease patients (four SC, three SS), aged four to 24
years, were submitted to sequential phlebotomies during periods from 18
months to four years.
METHODS:
The number of hospitalization days for crises was considered.
The volumes and frequencies of phlebotomies were adjusted according to
the patients ages, the hemoglobin concentrations and the serum ferritin
levels.
RESULTS:
One hundred and forty-four hospitalization days were recorded in the
seven patients in the year preceding the treatment.
During the study period, the annual numbers of hospitalization days
were respectively 20, five, six and one.
Mean hemoglobin concentration was 10.7 g/dL before phlebotomies and 8.8
to 9.2 g/dL during the four years of treatment.
Mean corpuscular volume, mean corpuscular hemoglobin concentration and
serum ferritin were also reduced.
The volume of phlebotomies was 116 to 39 mL/kg/year according to the
patients.
COMMENTS AND CONCLUSION:
The striking decrease of the number of hospitalization days for all the
patients suggests a closed relationship between therapy and clinical
improvement.
The mechanism of this effect is probably multifactorial:
a) the concentration of Hb level is known to influence the blood
viscosity and its decrease always improved rheology in sickle cell
disease patients;
b) the mean corpuscular hemoglobin concentration is a critical factor
concerning the HbS molecule polymerization in sickle cell disease, and
its slight reduction may have an important biological effect.
We observed these two biological modifications in our patients and
suggest that they mediate the clinical effects.
The iron deficiency induced by phlebotomies has no evident deleterious
consequence either on height and weight in the children or on
intellectual performance in any patients.
Publication Types: * Clinical trial
PMID: 10761600, UI: 20224666
--------
Promising New Class of Antibiotics Causes Bacteria
to Commit Suicide
By Stuart Fox
Posted 12.17.2009
As bacteria continue to grow more resistant to a wide
range of antibiotics, doctors are searching furiously
for better ways to kill infectious microbes.
Enter hydroxyurea.
Researchers at MIT and Boston University have discovered
that hydroxyurea, normally a drug prescribed for
sickle-cell anemia or psoriasis, also causes bacteria to
create their own poisons and kill themselves.
In all cases, hydroxyurea prevents DNA transcription.
When used to treat psoriasis or sickle-cell anemia,
hydroxyurea simply slows down the production of sick
cells.
But when used against a bacterium, the cessation of
DNA transcription begins a chain reaction that ends
with the bacterium producing hydroxyl free radicals.
Those free radical are like molecular buzz saws, and
they quickly chop the bacterium apart from the inside
out.
In fact, many antibiotics currently in use also kill
bacteria by inducing hydroxyl free radical production,
but hydroxyurea does so in a totally novel way.
Thus, no bacteria on Earth has evolved any resistance
to it.
That lack of resistances means hydroxyurea can serve
either as an antibiotic on its own, or as a helper to
other, more widely resisted, antibiotics.
And with multiple-drug-resistant bacteria becoming a
bigger and bigger problem, any help is welcome.
----------------------
Iron chelators hydroxyurea and bathophenanthroline
disulfonate inhibit DNA synthesis by different pathways.
Biochemistry and molecular biology international
1994;34(2):273-9.
1994: Alcaín F J; Löw H; Crane F L; Navas P
We previously showed that thrombin-stimulated DNA synthesis
in CCL 39 cells was inhibited by hydroxyurea (HU) and
bathophenanthroline disulfonate (BPS)
(Proc. Natl. Acad. Sci. USA, in press).
A clear difference exists between these two inhibitors.
Inhibition mediated by HU was immediate and must be present
in the culture medium.
BPS was equally effective when it was present in the medium
or after preincubation, but it required at least 12 h to
achieve maximal effect.
The permeable form 1,10 phenanthroline had the same inhibitory
effect in short-term incubations that BPS.
Moreover, 1,10 phenanthroline was cytotoxic in long-term
incubations indicating that the site of BPS inhibition was
outside the cell.
Further, long-term incubations with HU did not affect the
ability of the cell to reinitiate DNA synthesis after removal
of the chelator.