Research on the Mineral Selenium
The following research abstracts
are presented to reflect the findings of possible benefits from
minerals as a dietary supplement and nutritional supplement.
You will find more on the ionic
selenium page.
Vet Rec (ENGLAND) Oct 19 1996,
139 (16) p391-4
Because of the very low concentrations
of selenium in the dry matter of
grass, grass silage, hay and maize silage Slovenian dairy herds
need to be supplemented with selenium.
Selenium in the form of mineral and feed mixtures maintained
adequate mean (sd) blood serum selenium
concentrations of 43.9 (27.6) to 65.3 (18.5) micrograms/litre
in lactating cows, but in late lactation and in the dry period
when only mineral mixtures were used, about 60 per cent of the
cows had marginal serum selenium
concentrations, mainly because of the low intake of the mineral
supplement. In 18 herds which were either unsupplemented or
irregularly supplemented with selenium,
the mean (sd) concentrations in blood serum were 13.7 (5.5)
micrograms/litre and 17.4 (9.2) micrograms/litre, respectively,
for selenium and 2.98 (2.72) mg/litre
and 1.62 (1.73) mg/litre for vitamin E, indicating that under
extensive farming conditions in Slovenia the lack of both micronutrients
may be responsible for nutritional muscular dystrophy in calves.
Among 37 clinical cases, cardiorespiratory signs predominated
in 25 of the calves and skeletal myopathy was dominant in 12.
A very low mean serum selenium
concentration [9.7 (7.2) micrograms/litre] and typically high
activities of aspartate aminotransferase (AST) [1125 (373) U/litre]
and creatine kinase (CK) [9169 (3681) U/litre) were observed
for the myocardial form of the disease, and 2797 (550) U/litre
and 22,650 (13,500) U/litre were observed for the skeletal form
of the disease. A highly significant (P <0.0001) difference
in the selenium concentration of
liver dry matter between the regularly supplemented [402 (207)
micrograms/kg] and irregularly supplemented [173 (69) micrograms/kg]
herds was observed. If a minimum value of 300 micrograms/kg
of liver dry matter is accepted as the criterion for the determination
of adequate selenium status, 93
per cent of the samples from the irregularly supplemented herds
were selenium deficient. A similar
proportion was estimated to be selenium
deficient when the criterion was taken to be 30 micrograms selenium/litre
of blood serum.
J Am Vet Med Assoc (UNITED STATES)
Jul 1 1996, 209 (1) p130-6
OBJECTIVE--To identify common
clinical and diagnostic features of calves with aortic or iliac
artery thrombosis that might aid in antemortem diagnosis of
this condition. DESIGN--Retrospective case series. ANIMALS--9
calves or months old in which aortic or iliac artery thrombosis
was confirmed at necropsy. RESULTS--All calves had an acute
onset of paresis or flaccid paralysis of 1 or both hind limbs.
Affected limbs were hypothermic and had diminished spinal reflexes
and diminished pulse pressures. Diagnosis was definitively established
in 2 calves by use of angiography. All 9 calves died or were
euthanatized. CLINICAL IMPLICATIONS--This condition is rare
and could be mistaken for more common diseases of young cattle,
such as traumatic injury of the axial or appendicular skeleton,
vertebral osteomyelitis, nutritional muscular dystrophy associated
with vitamin E or selenium deficiency,
injury to the sciatic or femoral nerves, or clostridial myositis.
Nippon Rinsho (JAPAN) Jan 1996,
54 (1) p134-40
The concentration of selenium
(Se) and the activity of glutathione peroxidase (GSH-Px) in
plasma and erythrocytes were measured in healthy men and in
patients with Duchenne-type progressive muscular dystrophy (DMD).
In healthy men, the Se concentration in erythrocytes showed
a steep rise with aging and ascended gradually in plasma. The
GSH-Px activity in both plasma and erythrocytes clearly increased
with aging. The relationship between the Se concentration and
the GSH-Px activity in healthy men showed a parallel rise with
aging, but the coefficients of correlation were not very high
(r = 0.44 and 0.56 in plasma and erythrocytes, respectively.
In DMD patients, on the other hand, the Se concentration in
erythrocytes decreased steeply with aging, and it decreased
gradually in plasma. The GSH-Px activity in both plasma and
erythrocytes apparently increased as in healthy men with aging,
but the level was about 80% of that of healthy men. When selenite
(Se+4) is added to the whole blood in vitro at 25 degrees C,
it is rapidly taken up by erythrocytes (within several minutes)
and is then released into plasma (a period of 30 min), then
subsequent reuptake by erythrocytes is proceeded slowly. Our
attention was attracted to the pattern of selenite release from
erythrocytes of DMD patients.
ARCH. OPHTHALMOL. (USA), 1993,
111/1 (104-109)
We evaluated the hypothesis that
higher serum levels of micronutrients with antioxidant capabilities
may be associated with a decreased risk of neovascular age-related
macular degeneration by comparing serum levels of carotenoids,
vitamins C and E, and selenium
in 421 patients with neovascular age-related macular degeneration
and 615 controls. Subjects were classified by blood level of
the micronutrient (low, medium, and high). Persons with carotenoid
levels in the medium and high groups, compared with those in
the low group, had markedly reduced risks of neovascular age-related
macular degeneration, with levels of risk reduced to one half
and one third, respectively. Although no statistically significant
protective effect was found for vitamin C or E or selenium
individually, an antioxidant that combined all four micronutrient
measurements showed statistically significant reductions of
risk with increasing levels of the . Although these results
suggest that higher blood levels of micronutrients with antioxidant
potential, in particular, carotenoids, may be associated with
a decreased risk of the most visually disabling form of age-related
macular degeneration, it would be premature to translate these
findings into nutritional recommendations.
Gastroenterology (USA), 1996,
110/4 (1150-1155)
Background and Aims: Cirrhosis
is a potentially lethal condition for which there is no proven
effective therapy. The aim of this study was to compare the
effects of hepatic stimulator substance, traditional Chinese
herbal medicine, selenium plus
vitamin E, and ciprofloxacin treatment on biochemical and histological
features of fibrosis in rats with carbon tetrachloride (CCl4)/ethanol-induced
cirrhosis. Methods: One hundred twenty adult Wistar rats were
divided into six study groups (20 rats/group): healthy controls,
CCl4/ethanol-injured rats left untreated, and CCl4/ethanol-injured
rats treated for 4 weeks with either hepatic stimulator substance,
traditional Chinese herbal medicine, a combination of selenium
plus vitamin E, or ciprofloxacin. After the 4-week treatment,
rats were killed and the following parameters of hepatic fibrosis
were determined: hepatic hydroxyproline and proline levels,
serum hyaluronic acid concentrations, and histological staining
of hepatic tissue. Results: Hepatic fibrosis was significantly
improved in all four treated groups compared with the untreated
CCl4/ethanol-injured controls. Improvements were most striking
in the groups treated with traditional Chinese herbal medicine
and ciprofloxacin. Conclusions: The data indicate that hepatic
stimulator substance, traditional Chinese herbal medicine, selenium
plus vitamin E, and ciprofloxacin significantly decrease the
amount of hepatic fibrosis caused by CCl4/ethanol injury in
rats.
Nutrition Research (USA), 1996,
16/9 (1607-1612)
Male albino rats, age 28 days,
were fed a diet containing both vitamin E (10 g/kg) and selenium
(5 mg/kg) or a diet lacking these antioxidants. Animals were
examined for renal function after 4, 8, 12 and 16 wk on the
respective diets. After 8 wk, animals on the deficient diet
weighed less than controls (15%, P <0.01), and this became
more pronounced by 16 weeks (25%, P <0.01). Expressed on
a body weight basis, kidney wet weights did not differ between
the two groups of animals. Urine volume increased in the animals
fed the deficient diet at 8 weeks (66%, P <0.01) and this
was maintained at 16 weeks (35%, P <0.01). Similar increases
were observed for the rates of excretion of urinary total protein
(77% elevation at 16 wk, P <0.01) and urinary acid phosphatase
(51% elevation, P <0.01). At 16 wk, the specific activity
of renal acid phosphatase in the animals given the deficient
diet was reduced in cortex (57%, P <0.01) and medulla (20%,
P <0.01), but not in papilla. These data indicate that dietary
antioxidant deficiency causes progressive and pronounced renal
damage.
Med Hypotheses (ENGLAND) Jun
1993, 40 (6) p364-6
Reid found selenium
(Se) deficient soils were a common factor in two populations
with the highest incidence of SIDS world-wide (Indian population
of King County Washington State, USA and the population of Canterbury,
New Zealand). Reid compared a map of the selenium
responsive livestock areas in New Zealand with areas of low
soil iodine (I). She found that the 1989 report of areas of
the highest SIDS incidence coincided with Se responsive livestock
areas combined with low soil iodine. Foster found the 1983-84
incidence of SIDS in USA has the strongest positive correlation
with the incidence of goitre in World War I troops (1916). Sodium
and strontium were positively related. Emery found a hypernatraemic
SIDS victim in a very cold environment. Robertson and Parker
associated increased sodium (Na) (used in Scunthorpe, England,
as a water softener) with increased incidence of SIDS. Godwin's
study of White Muscle Disease in lambs describes Se protection.
Skeletal muscle mitochondria from dystrophic animals showed
lowered respiratory rates with palmitoyl-dl-carnitine and acetyl-dl-carnitine
as substrate. Dystrophic organelles failed to respond to ADP.
Rognun found elevated hypoxanthine and an enhanced immune response
in most SIDS victims. A syndrome associated with potassium deficiency
has been described as a killer of healthy, young Asian men,
most often during sleep. This paper describes the interactions
of sodium (Na), potassium (K), selenium
(Se), and iodine (I) to some factors affecting the utilization
of oxygen and the production of energy. (19 Refs.)
Med Hypotheses (ENGLAND) Mar
1981, 7 (3) p271-83
Sodium restriction is not the
only nutritional measure likely to prove valuable in the treatment
and prevention of hypertension. The hypotensive effects of central
adrenergic stimulation can be promoted by supplementary tyrosine,
insulin potentiation (as with GTF), and (possibly) high-dose
pyridoxine. Insulin potentiators (GTF) and prostaglandin precursors
(essential fatty acids) should have direct relaxant effects
on vascular muscle. A high potassium, low sodium diet, coenzyme
Q, and prevention of cadmium toxicity (as with dietary selenium)
may act to offset renally-mediated pressor influences. Functional
combinations of these measures might prove to be substantially
effective, in which case they would offer considerable advantages
over potentially toxic drug therapies.
Ann Epidemiol (UNITED STATES)
Sep 1993, 3 (5) p571-5
The evidence that treatment of
hypertension prevents stroke is incontrovertible. Several observations,
however, suggest that improvements in the prevalence of antihypertensive
treatment cannot explain all of the recent decline in stroke
mortality. Changes in nutritional patterns may explain some
of the observed decline. Prospective studies have demonstrated
conclusively an independent, increasing risk of hemorrhagic,
but not thrombotic, stroke at higher levels of alcohol use.
Stroke mortality is associated inversely with fat and protein
intake. Dietary sodium has been linked to stroke in ecologic
studies but not in prospective studies. Ecologic studies have
suggested that foods high in vitamin C and potassium protect
against stroke; an inverse association of potassium intake with
fatal stroke has been demonstrated in cohort studies. Two studies
in humans also suggest a protective effect of serum selenium
against subsequent stroke. Determination of the influence of
nutrients on stroke incidence offers tantalizing opportunities
for future research and possibly, intervention.
European Journal of Clinical
Nutrition (United Kingdom), 1997, 51/4 (266-272)
Objectives: Antioxidant defense
status was investigated in HIV-infected patients by measuring
serum selenium, erythrocyte glutathione
peroxidase (GSH-Px) activity, plasma thiol (-SH) and glutathione
(GSH) concentrations along with the assessment of the clinical
stage and surrogate markers of HIV-disease. Design, setting
and subjects: Serum selenium levels
were determined cross-sectionally in 104 sequentially selected
HIV-infected patients (83 outpatients and 21 patients with ongoing
AIDS defining events). The patients were classified into three
stages of the disease, I, II and III according to the 1993 Centers
For Disease Control (CDC) classification system for HIV-infection.
GSH-Px activities, plasma SH and plasma GSH concentrations were
determined in a subset of 24 patients at stage I and 12 patients
at stage III with an active AIDS-defining disease. Results:
Mean serum selenium levels were
lower in CDC stage II (68.7 plus or minus 20.9 microg/l; P <0.01;
n="34)" and stage III (51.4 plus or minus 14.7 microg/l;
P ( 0.01; n="37)" HIV-infected patients than in healthy
subjects (89.2 plus or minus 20.9 microg/l; n="72)"
and stage I patients (82.3 plus or minus 20.5; microg/l; n="33)."
Serum selenium levels were positively
correlated with CD4-count (r="0.42;" P < 0.001;
n="104)" and inversely with levels of soluble tumor
necrosis factor receptors type II (r="-0.58;" P <
0.01; n="35)," neopterin (r="-0.5;" P <
0.001; n="80)" and beta2-microglobulin (r="-0.4;"
P < 0.001; n="94)." Hepatitis C virus (HCV) and
HIV-coinfected patients at CDC stages I and II showed markedly
lower selenium concentrations compared
to HIV-infected patients without concomitant HCV-infection.
Serum selenium and GSH-Px activity
in hospitalized AIDS patients was significantly lower as compared
to asymptomatic patients and healthy subjects, whereas plasma
SH and GSH concentrations were lower in both, asymptomatic and
AIDS-patients, than in the controls. Conclusion: The results
show that stages I-III of HIV-disease are characterized by significant
impairments of antioxidative defenses provided by selenium,
GSH-Px, SH-groups and GSH.
