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Biomedical subjects

R C Griggs

Publications and source records attributed to R C Griggs.

At least 145 records · Page 8Linked to original sources
PubMed1983

Intravenous treatment of hypokalemic periodic paralysis.

Acute attacks of weakness in patients with hypokalemic periodic paralysis can usually be treated with oral potassium preparations. Occasional patients, however, require intravenous (IV) potassium administration. We studied a patient with hypokalemic periodic paralysis to determine the effect of using 5% glucose as a diluent for potassium administration during acute attacks of weakness. Administration of IV potassium chloride in 5% glucose (50 mEq/L) was associated with a worsening of strength and no rise in potassium level. Intravenous potassium in 5% mannitol was associated with a rise in potassium and improvement in strength. This study confirms the hazard of using glucose-containing solutions for correction of hypokalemia.

Adult↗
PubMed1983

Clinical investigation in Duchenne dystrophy: 2. Determination of the "power" of therapeutic trials based on the natural history.

A prospective study of 114 patients with DMD provided data for "power" calculations for future therapeutic trials. There was a decline in strength of 0.4 units per year (on a 0-10 scale). Contractures of the iliotibial bands, hip flexors, and heel cords developed before 6 years. Contractures of other joints accompanied the increased use of wheelchairs. All children walked until 8 years with functional "improvement" between 3-6 years. Children of the same age varied widely in their strength, degree of contracture, and functional abilities. Fifteen percent of the patients appear to have a milder variety of the disease and are termed "outliers." To test a drug which might slow the disease to 25% of its original rate of progression, two groups (placebo and treatment) of 40 patients each would have to be followed for one year.

Adolescent↗
PubMed1983

Quantitative testing of handgrip strength, myotonia, and fatigue in myotonic dystrophy.

An electrically calibrated, isometric hand dynamometer was used to quantitate maximum voluntary contraction (MVC(, relaxation time and fatigue time (at 50% MVC) in 18 normal and 10 myotonic dystrophy subjects. Precise measurements of MVC and fatigue time were obtained in normals and myotonic dystrophy patients. Relaxation times were markedly prolonged and were quite variable in all patients with myotonic dystrophy in contrast to the highly reproducible times in normals. Neither "warm-up" activity nor acetazolamide treatment altered relaxation time.

Acetazolamide↗
PubMed1983

Influence of muscle wasting on oral glucose tolerance testing.

1. The effect of muscle wasting on glucose tolerance was studied. Oral glucose tolerance testing was performed in three groups of wasted patients: myotonic dystrophy (11); amyotrophic lateral sclerosis (10); other lower motor neuron disease (four). Normal subjects (11) and non-wasted neurological disease (five) controls were studied for comparison. An average decrease of 29-36% in lean body mass was present in the wasted individuals. 2. A slightly higher plasma glucose occurred at 120 min after glucose ingestion in wasted compared with non-wasted individuals (119.2 +/- 5 vs. 99.9 +/- 4 mg/100 ml, P less than 0.05). 3. Normal insulin release was seen in all patient groups except those with myotonic dystrophy, who displayed marked hyperinsulinaemia from 30 to 240 min after glucose. This excessive insulin output was not due to a greater absolute decrease in lean body mass in the myotonic dystrophy patients than in the other wasted subjects. No significant correlation between the cumulative insulin release or peak insulin values and the absolute or height adjusted lean body mass was noted within any of the wasted or non-wasted groups. 4. In contrast to the findings of many studies, only clinically insignificant glucose intolerance was detected in ambulatory wasted patients and only patients with myotonic dystrophy had abnormal insulin release. Muscle loss appeared to exert only a slight influence on glucose regulation in these wasted patients and no typical effect of muscular atrophy on pancreatic insulin release was noted.

Adolescent↗
PubMed1983

The assessment of muscle mass in progressive neuromuscular disease.

We performed sequential studies of two methods used to estimate muscle mass in 34 patients with progressive neuromuscular disease for periods of up to 52 months. Creatinine excretion and total body potassium were low at the outset in virtually all patients. Creatinine excretion continued to decline in most patients, but total body potassium did not decline significantly. Creatinine excretion may measure declining muscle mass more accurately than total body potassium, but both measurements can estimate muscle mass for metabolic studies or therapeutic trials.

Adolescent↗
PubMed1982

Recovery from the 'locked-in' syndrome.

Four patients made substantial recovery following the locked-in syndrome of vascular origin. Clinical and radiologic features supported the presence of ventral pontine infarction secondary to basilar artery occlusion. Quadriplegia and mutism persisted for one to 12 weeks before recovery of motor function began. Improvement continued over several years. All patients regained functional though dysarthric speech. Three of the four patients are ambulatory, one without assistance. As a few patients make a notable recovery from the locked-in syndrome resulting from ventral pontine infarction, aggressive supportive therapy should be considered in the early months of the syndrome.

Adult↗
PubMed1982

Sjögren's syndrome and polymyositis or dermatomyositis.

Of four patients with Sjögren's syndrome, three had polymyositis and one had dermatomyositis. In all, deposition of IgG, IgA, IgM, and C3 was observed in muscle by immunofluorescent techniques. Serologic studies revealed elevated levels of serum IgG and IgM, rheumatoid factor, and antinuclear antibody with specificity for SS-A and SS-B antigens. In muscle there was a mononuclear cell infiltrate with plasma cell predominance around small vessels and capillaries. Ultrastructural changes in the vessels included reduplication of the basement membrane, endothelial thickening, and numerous tubuloreticular and dense inclusions. In two patients, electrondense deposits were noted in the microvasculature. This combination of immunoglobulin deposition in muscle, prominent microvascular changes, and characteristic serology suggests that the myositis in Sjögren's syndrome may result from small-vessel injury by autoantibodies or circulating immune complexes.

Adult↗
PubMed1982

Skeletal muscle catabolism in amyotrophic lateral sclerosis and chronic spinal muscular atrophy.

ALS and chronic spinal muscular atrophy are characterized by wasting of skeletal muscle, suggesting accelerated catabolism or reduced synthesis of muscle protein. We studied seven patients with ALS and three with chronic spinal muscular atrophy using 24-hour urinary 3-methylhistidine excretion as a measure of the rate of muscle catabolism and 24-hour urinary creatinine excretion as an index of significantly and similarly higher in both groups of patients than in controls (p less than 0.0005), implying a state of accelerated skeletal muscle protein catabolism in these diseases.

Adult↗
PubMed1982

Diagnostic usefulness of intramuscular nerve bundles.

The diagnostic usefulness of pathological changes in intramuscular nerve bundles was assessed in 555 consecutive muscle biopsy specimens. Nearly half (45%) of the biopsy specimens contained at least six nerve fibers. Slight endoneurial fibrosis was present in all biopsy specimens from patients over age 10 years. Moderate or marked fibrosis was infrequent in patients lacking electrodiagnostic, clinical, or muscle biopsy evidence of denervation but was present in 90% or more of patients with either spinal muscular atrophy or peripheral neuropathy; fibrosis correlated well with the presence of muscle fiber type grouping and grouped atrophy. Specific pathological diagnoses suggested by nerve bundles included amyloid, dysglobulinemic, and hypertrophic neuropathies.

Adolescent↗
PubMed1981

Evaluation of pulmonary function in neuromuscular disease.

Pulmonary function tests were performed on 40 patients with neuromuscular disease. The maximum expiratory pressure was the most sensitive indicator of weakness and was decreased in 87% of adult patients. A comparison of Stead-Wells, electronic (Vanguard), and bellows spirometry (Vitalor) indicated an excellent correlation between the Stead-Wells and electronic devices. The bellows spirometer consistently underestimated volumes, particularly in severely weak patients.

Adolescent↗
PubMed1981

Renal involvement in Refsum's disease.

Renal hemodynamic and tubular functions were measured in a patient with Refsum's disease before and after 12 weeks of twice-weekly plasmaphereses. Percutaneous renal biopsy was performed before initiation of plasmapheresis. These studies were performed to (1) define the nature of the renal lesions and the effects of phytanic acid accumulation on renal functions, and (2) assess the effects of lowering the plasma phytanic acid level on renal functions. The patient, a 39 year old woman, had lipiduria, glycosuria, cylindruria, minimal proteinuria and mild azotemia initially. Renal lesions consist of extensive vacuolization and mitochondrial changes of the tubular epithelial cells, vacuolization of the visceral epithelial cells of the glomeruli, and slight to moderate mesangial sclerosis. The impaired renal hemodynamic function and various tubular functions improved following plasmaphereses associated with reduction of plasma phytanic acid. Over-all clinical improvement was also evident.

Adult↗
PubMed1981

Abnormal regulation of monocyte insulin-binding affinity after glucose ingestion in patients with myotonic dystrophy.

Insulin insensitivity of uncertain etiology often exists in myotonic muscular dystrophy, a multitissue, autosomal dominant disorder hypothesized to be a hereditary membrane disease. The present studies show that monocytes from patients with myotonic dystrophy fail to demonstrate the normally observed qualitative increase in insulin-binding affinity after oral glucose loading. Monocytes from 10 normal volunteers developed a significantly increased insulin-binding affinity by 2 hr after glucose ingestion (mean +/- SEM, 11.7 +/- 2.7 ng/ml compared to basal 50% insulin displacement value of 23.3 +/- 2.2 ng/ml, P less than 0.005). This increase was maintained at 5 hr (13.5 +/- 2.7 ng/ml, P less than 0.05). In contrast, no significant increase in monocyte insulin-binding affinity occurred in cells from nine myotonic dystrophy patients at 2 and 5 hr after glucose loading (50% insulin displacement values: basal, 14.2 +/- 2.8 ng/ml; 2 hr, 16.7 +/- 1.7 ng/ml; 5 hr, 10.8 +/- 2.1 ng/ml). These alterations document the presence of abnormalities in the insulin receptor or receptor-associated processes that modulate insulin binding. A hereditary plasma membrane defect may underlie these findings. This abnormality may have an etiologic role in the decreased insulin sensitivity that frequently afflicts patients with myotonic dystrophy.

Glucose↗
PubMed1981

Hypokalemic periodic paralysis exacerbated by acetazolamide.

Although acetazolamide usually prevents paralytic attacks in hypokalemic periodic paralysis, not all patients benefit from this treatment. We studied a father and two sons in whom attack frequency and severity increased on acetazolamide. Administration of triamterene virtually abolished attacks in three separate single-blind trials totaling more than 12 months. Spontaneous and glucose-insulin provoked occurred with only slight hypokalemia. Acetazolamide produced slight hypokalemia and provoked attacks of weakness whereas triamterene increased potassium levels significantly. Certain patients with hypokalemic periodic paralysis are worsened by acetazolamide, perhaps because of its kaliopenic effect. Triamterene may be effective in some of these patients.

Acetazolamide↗
PubMed1981

Acute effects of acetazolamide in hyperkalemic periodic paralysis.

We studied the effect of acetazolamide on plasma potassium in normals and in two patients with hyperkalemic periodic paralysis. Administration of acetazolamide for 48 hours lowered mean plasma potassium in normals from 4.01 to 3.56 mEq per liter (p less than 0.001) and in the patients from 4.55 to 4.00 mEq per liter (p less than 0.001). This kaliopenic effect of acetazolamide may account for its therapeutic action in hyperkalemic periodic paralysis.

Acetazolamide↗