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Biomedical subjects

R Simonsen

Publications and source records attributed to R Simonsen.

12 recordsLinked to original sources
PubMed1995

Two successful double-blind trials with coenzyme Q10 (vitamin Q10) on muscular dystrophies and neurogenic atrophies.

Coenzyme Q10 (vitamin Q10) is biosynthesized in the human body and is functional in bioenergetics, anti-oxidation reactions, and in growth control, etc. It is indispensable to health and survival. The first double-blind trial was with twelve patients, ranging from 7-69 years of age, having diseases including the Duchenne, Becker, and the limb-girdle dystrophies, myotonic dystrophy. Charcot-Marie-Tooth disease, and the Welander disease. The control coenzyme Q10 (CoQ10) blood level was low and ranged from 0.5-0.84 microgram/ml. They were treated for three months with 100 mg daily of CoQ10 and a matching placebo. The second double-blind trial was similar with fifteen patients having the same categories of disease. Since cardiac disease is established to be associated with these muscle diseases, cardiac function was blindly monitored, and not one mistake was made in assigning CoQ10 and placebo to the patients in both trials. Definitely improved physical performance was recorded. In retrospect, a dosage of 100 mg was too low although effective and safe. Patients suffering from these muscle dystrophies and the like, should be treated with vitamin Q10 indefinitely.

Adolescent↗
PubMed1990

Protective effect of KCl loading in gentamicin nephrotoxicity.

Aminoglycoside nephrotoxicity in experimental animals can be reduced by calcium loading, inducing diabetes, and giving thyroid hormone, while a potassium deficient diet enhances aminoglycoside nephrotoxicity. This study investigated whether potassium loading protects against gentamicin nephrotoxicity in the rat. In part I, group GK ate a diet containing 3.5% potassium and drank 0.2 mol/L KCl. Pair-fed rats eating a standard diet, group G, ate a 1% potassium diet and drank water. After 10 days, each group received gentamicin subcutaneously, 60 mg/kg twice daily for 8 days. The control groups, K and C, received the high or normal potassium diet, respectively. To control for a protective effect from a high solute load, the effect of equimolar NaCl loading was studied in group GNa and Na. At the end of the 8 days of gentamicin, inulin clearance was significantly higher in GK compared with G(0.6 +/- 0.1 v 0.3 +/- 0.1 mL/min per 100 g body weight [BW], P less than 0.05), but group GNa (0.4 +/- 0.1 mL/min per 100 g BW) was not different from group G. Morphological studies demonstrated that potassium-loaded rats (group GK) had significantly less proximal tubular necrosis compared with rats on a standard potassium diet, group G. Sodium loading did not protect against cellular necrosis. Part II studied renal function, cortical Na,K-adenosine triphosphatase (ATPase) and gentamicin accumulation after 2 days of gentamicin to determine the early functional and biochemical effects of potassium loading before overt renal functional impairment.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Prevention of detrimental effect of cyclosporin A on vascular ingrowth of transplanted pancreatic islets with verapamil.

The revascularization of pancreatic islet clusters transplanted beneath the renal capsule was studied in a syngeneic mouse model. The degree of vascular ingrowth was visualized by in vivo fluorescence microscopy (fluorescein isothiocyanate-dextran) and judged by a semiquantitative method from coded video recordings. The recipients of isografts were divided into four groups, depending on their daily immunosuppressive treatment: 1) none (controls), 2) 15 mg/kg cyclosporin A (CsA), 3) 0.4 mg/kg verapamil + 15 mg/kg CsA, and 4) 20-30 mg/kg methylprednisolone. In control animals, capillary ingrowth was first demonstrated on day 6, followed by progressive vascularization up to day 34. After 6 mo, the vascular architecture was similar to that seen in normal islets in situ. CsA alone significantly decreased vascular ingrowth on day 14 compared with controls (P less than .02). Verapamil prevented the detrimental effect of CsA (P less than .01), probably by improving renal subcapsular blood flow. Methylprednisolone did not affect revascularization compared with control animals at day 14. We conclude that CsA inhibits vascular ingrowth into transplanted pancreatic islets, which is likely to have clinical implications. The prevention of CsA vascular ingrowth inhibition by a calcium antagonist indicates a possible approach to the correction of this problem, particularly when the renal capsule is used as the recipient's transplant site.

Animals↗
PubMed1988

Cryopreserved human fetal pancreas: a source of insulin-producing tissue?

Human fetal pancreata (HFP) were obtained from dilatation and extraction aborted fetuses of 11-18 weeks' gestation. The pancreas was excised under sterile conditions and kept in culture medium at 4 degrees C, prior to stepwise digestion into 50- to 150-micron fragments. The fragmented pieces were allowed to sediment by gravity, then transferred to tissue culture for 24-48 h, and cryopreserved. The freeze-thaw protocol used stepwise equilibration with dimethyl sulfoxide, nucleation of the sample at -10 degrees C, and a slow cooling rate of 0.25 degrees C/min to -40 degrees C, followed by submersion in liquid nitrogen (-196 degrees C). Rapid thawing at 300 degrees C/min from -196 degrees C was employed. Both fresh and frozen-thawed HFP fragments appeared viable as judged by light and electron microscopy, and secreted insulin in a perifusion system upon stimulation with glucose (28 mM) and theophylline (10 mM) or glucose (2.8 mM) and theophylline (10 mM). Six patients with Type I insulin-dependent diabetes mellitus, already requiring immunosuppression for a kidney transplant, had intraportal injection of 20 cryopreserved-thawed and pooled HFP fragments. Up to the 1-year post-transplant follow-up, there has been no evidence of in vivo insulin or C-peptide production. The usefulness of cryopreserved human fetal pancreata as a source of insulin-producing tissue for diabetic patients, therefore, remains to be demonstrated.

Abortion, Spontaneous↗
PubMed1986

Mural thrombi of the right atrium and acute bacterial endocarditis complicating a LeVeen shunt.

A cirrhotic woman with a LeVeen shunt developed right atrial thrombi, acute bacterial endocarditis, and a major pulmonary embolus. The right atrial mural thrombi and resultant pulmonary emboli arose as a result of the placement of the venous end of the LeVeen shunt within the right atrium. This untoward event must be added to the growing list of complications associated with the placement of such catheters.

Adult↗
PubMed1986

Protection by thyroxine in nephrotoxic acute renal failure.

Thyroxine (T4) protects against ischemic and nephrotoxic experimental acute renal failure (ARF). This study examined functional, biochemical, and morphological markers of uranyl nitrate (UN)-induced renal injury in the rat to determine the cellular site at which T4 exerts its protective effect. In experimental group UNT4, 1-thyroxine (10 micrograms/100 g body wt) was given for 10 days prior to and for 4 days following a single subcutaneous injection of UN (0.5 mg/kg body wt). Group UN received only UN, and group CT4 received only T4 for 14 days. Five days after UN administration, plasma creatinine rose from base line in group UNT4 (0.52 +/- 0.30 to 0.84 +/- 0.08 mg/dl, P less than 0.025) and group UN (0.52 +/- 0.03 to 1.64 +/- 0.13 mg/dl, P less than 0.001) but not in group CT4 (0.47 +/- 0.02 to 0.48 +/- 0.04 mg/dl, NS). However, plasma creatinine in group UNT4 was significantly lower than group UN (0.84 +/- 0.08 vs. 1.64 +/- 0.13 mg/dl, P less than 0.001). T4 administration stimulated the basolateral membrane-bound enzyme Na-K-ATPase in the renal cortex homogenate in group UNT4 (13.9 +/- 0.5 micron X mg protein-1 X h-1, P less than 0.005) and group CT4 (16.3 +/- 0.6 micron X mg protein-1 X h-1, P less than 0.001) when compared with controls (11.7 +/- 0.5 micron X mg protein-1 X h-1). Na-K-ATPase activity fell in group UN to 10.0 +/- 0.6 micron X mg protein-1 X h-1 (P less than 0.025).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗
PubMed1985

Biochemical rationale and the cardiac response of patients with muscle disease to therapy with coenzyme Q10.

Cardiac disease is commonly associated with virtually every form of muscular dystrophy and myopathy. A double-blind and open crossover trial on the oral administration of coenzyme Q10 (CoQ10) to 12 patients with progressive muscular dystrophies and neurogenic atrophies was conducted. These diseases included the Duchenne, Becker, and limb-girdle dystrophies, myotonic dystrophy, Charcot-Marie-Tooth disease, and Welander disease. The impaired cardiac function was noninvasively and extensively monitored by impedance cardiography. Solely by significant change or no change in stroke volume and cardiac output, all 8 patients on blind CoQ10 and all 4 on blind placebo were correctly assigned (P less than 0.003). After the limited 3-month trial, improved physical well-being was observed for 4/8 treated patients and for 0/4 placebo patients; of the latter, 3/4 improved on CoQ10; 2/8 patients resigned before crossover; 5/6 on CoQ10 in crossover maintained improved cardiac function; 1/6 crossed over from CoQ10 to placebo relapsed. The rationale of this trial was based on known mitochondrial myopathies, which involve respiratory enzymes, the known presence of CoQ10 in respiration, and prior clinical data on CoQ10 and dystrophy. These results indicate that the impaired myocardial function of such patients with muscular disease may have some association with impaired function of skeletal muscle, both of which may be improved by CoQ10 therapy. The cardiac improvement was definitely positive. The improvement in well-being was subjective, but probably real. Likely, CoQ10 does not alter genetic defects but can benefit the sequelae of mitochondrial impairment from such defects. CoQ10 is the only known substance that offers a safe and improved quality of life for such patients having muscle disease, and it is based on intrinsic bioenergetics.

Administration, Oral↗
PubMed1984

Interpreting the profile of liver-function tests in pediatric liver transplants.

Results of traditional laboratory tests of liver function were correlated with the clinical course in 26 pediatric patients after liver transplantation. On the basis of clinical outcome after transplantation, the patients were divided into two groups: (a) uncomplicated course with short hospital stay, and (b) post-transplantation course complicated by multiple clinical problems. The patterns of results for tests reflecting liver function--bilirubin (total and conjugated), aspartate (EC 2.6.1.1) and alanine (EC 2.6.1.2) aminotransferases, and gamma-glutamyltransferase (gamma GT, EC 2.3.2.2)--were consistent with the clinical findings in these patients. Values for alkaline phosphatase (EC 3.1.3.1), however, were only rarely increased, even when there was clinical evidence of biliary obstruction. Not only was serum gamma GT increased in obstructive jaundice, but this sometimes was the only test giving results outside the normal limits. We suggest that the persistent and marked increases of gamma GT observed in half of the patients may have resulted from immune-mediated damage to the transplanted liver.

Adolescent↗