PubMed Health⌕ Search

Biomedical subjects

R J Hawley

Publications and source records attributed to R J Hawley.

At least 55 records · Page 3Linked to original sources

Five-year follow-up of Friedreich's ataxia cardiomyopathy.

Ten patients with Friedreich's ataxia were reexamined at a five-year follow-up with electrocardiography and echocardiography. The three patients who initially had had the smallest left ventricular diastolic dimensions relative to their body surface areas (decreased 23% to 25% below predicted dimensions) had undergone dilatation of their left ventricles and atria, with decreasing fractional shortening of the left ventricle, but stable to decreasing ventricular wall thickness. The other seven patients, whose ventricular diastolic dimensions were initially closer to those predicted for their body surface areas, had not undergone significant dilatation. However, their left ventricular posterior walls and interventricular septa had thickened at a mean rate of 0.019 mm/mo. The interplay of these tendencies to hypertrophy and dilatation may explain the disagreement about the type of hypertrophic cardiomyopathy in Friedreich's ataxia.

Adolescent↗

Cerebrospinal fluid 3-methoxy-4-hydroxyphenylglycol and norepinephrine levels in alcohol withdrawal. Correlations with clinical signs.

Cerebrospinal fluid (CSF) and plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) concentrations were significantly elevated in patients during the alcohol withdrawal syndrome. When CSF MHPG was corrected using a formula proposed to determine CSF MHPG levels of central origin, these values were still significantly elevated when compared with control values. The MHPG concentrations in CSF also showed significant positive correlations with heart rate, systolic and diastolic blood pressures, tremor, anorexia, and sweating. The results of this study indicate increased presynaptic release of norepinephrine during alcohol withdrawal.

Adult↗

Effects of ultraviolet light on the in vitro assembly of microtubules.

Exposure of microtubular protein to ultraviolet light inhibits its assembly into morphologically normal microtubules. This effect appeared to result primarily from damage to the tubulin dimers. The damage consisted of a conformational change, a loss of two free sulfhydryl groups, a production of higher molecular weight cross-linked species, and the formation of aggregated amorphous material upon polymerization.

Animals↗

Computed tomographic patterns of muscles in neuromuscular diseases.

Computed tomographic (CT) scans of muscle in 35 patients with neuromuscular diseases showed distinct patterns in nerve and muscle diseases. Neural diseases first showed as muscle atrophy, with decreased density in the muscles occurring later in the course of disease. Primary muscle diseases showed early decreased density in the muscles, with atrophy occurring later. The CT scan allows objective assessment of muscle mass and may be used to help select muscles for biopsy.

Adolescent↗

Families with myotonic dystrophy with and without cardiac involvement.

Study of 30 patients with myotonic dystrophy and 17 unaffected family members in a total of 18 families by echocardiography and ECG, including noninvasive His-bundle recording, appeared to show two phenotypes of myotonic dystrophy: those with and those without substantial cardiac involvement. Besides the 29% incidence of asymptomatic mitral valve prolapse common to many neuromuscular diseases, 20% of families had progressive involvement of the cardiac conduction system. It is important to recognize these families in order to treat patients with cardiac pacemakers who are rapidly progressive or symptomatic. If one patient with myotonic dystrophy is found to have myotonic heart disease with cardiac block or arrhythmia, it should be expected in other family members with myotonic dystrophy.

Arrhythmias, Cardiac↗

Possible enhancement of vincristine neuropathy by VP-16.

Eleven consecutive patients with small cell carcinoma of the lung treated intensively with a combination chemotherapy regimen cyclophosphamide, Adriamycin, VP-16, and vincristine experienced peripheral neuropathy. Four of the 11 patients had severe (Grade III) neuropathy, leaving them virtually bedridden; the remaining seven patients had mild to moderate neuropathy. Only 8 of the 14 patients treated less intensively with vincristine and VP-16 had Grade I and II neuropathy. Predisposing factors for severe neuropathy included advanced age and preexisting peripheral neuropathy. All patients' performance status declined and all lost much weight before developing neuropathy. From accumulated treatment experience of small cell carcinoma with vincristine alone or with vincristine, Adriamycin, cyclophosphamide combinations, the authors feel that the severe neuropathy observed was due to an interaction of vincristine and VP-16. This conclusion is supported by electron microscopic observation of electronopaque granular degeneration of the myelin lamellae of affected nerve fibers.

Aged↗

Left ventricular relaxation, mitral valve prolapse, and intracardiac conduction in myotonia atrophica: assessment by digitized echocardiography and noninvasive His bundle recording.

Myotonia atrophica, a neuromuscular disease marked by autosomal dominant transmission and delayed relaxation of skeletal muscle, has been associated with cardiac failure, conduction abnormality and mitral prolapse (MVP). In order to determine the relaxation rate of cardiac muscle, left ventricular (LV) size and function, and the presence of MVP, 30 patients with myotonia atrophica were studied using digitized M-mode echocardiography (MME). Intracardiac conduction intervals were determined by noninvasive His bundle recording (HBR) from surface electrodes using a high-resolution, R-wave triggered, signal averaging computer. Neurologically unaffected first-degree relatives of the patients with myotonia atrophica were also studied to determine if cardiac abnormalities may be present in the absence of neurologic manifestations of the disease. Peak normalized diastolic endocardial velocity in patients with myotonia atrophica (3.7 +/- 0.8 sec-1) did not differ from unaffected first-degree relatives (3.8 +/- 0.8 sec-1) or normal subjects (3.6 +/- 0.8 sec-1). Systolic LV function and LV dimensions on MME were normal in both groups. However, MVP was present in 7 of 24 (29%) of patients who could be evaluated, but not in unaffected first-degree relatives. Despite normal LV systolic and diastolic function, infranodal intracardiac conduction was prolonged in patients with myotonia atrophica (average HV interval 50 +/- 5 SD msec) but not in neurologically unaffected relatives (average HV interval 40 +/- 5 msec). Delay in proximal intracardiac conduction was also found in patients with myotonia atrophica (average PH interval 140 +/- 20 msec) but not in neurologically unaffected relatives (average PH interval 115 +/- 6 msec). Hence cardiac findings in myotonia atrophica include proximal and distal conduction delay by external HBR even in the absence of abnormality of the standard 12-lead ECG. There may also be an increased frequency of MVP; however, early diastolic relaxation of the LV is unimpaired, and cardiac manifestations of myotonia are not transmitted independently of neurologic abnormality.

Adolescent↗

The course of alcoholic-nutritional peripheral neuropathy.

63 patients with alcoholic-nutritional peripheral neuropathy were given neurologic, electrophysiologic and nutritional examinations. 24 of these patients were reexamined later in the course of their disease, after from 2 to 72 months (mean 33). Alcoholic-nutritional neuropathy appeared and worsened after bouts of heavy alcohol intake and malnutrition. Initially it was sensory and symmetric in character, with prominent involvement of the posterior tibial nerves. With repeated attacks it became more proximal, more motor, and associated with more severe slowing of nerve conduction velocity. 11 of the patients were able to stop drinking alcohol. Initial subjective improvement was seen within the first week or two, but substantial improvement was not seen for 5 to 6 months. Most leg motor nerve velocity improved at a mean rate of increase of 0.12 M/sec per abstinent month. Large motor units and slowed nerve conduction persisted in "cured" patients. The largest motor units detected in the legs grew, despite alcohol intake.

Adult↗

CSF levels of norepinephrine during alcohol withdrawal.

Cerebrospinal fluid norepinephrine (NE) levels were determined by radioenzymatic assay in 21 patients with a variety of neurological diseases and 49 patients in acute alcohol withdrawal. A second determination was made in 19 patients who had recovered from the alcohol withdrawal syndrome. Cerebrospinal fluid NE concentration was higher in the patients during alcohol withdrawal (192.3 plus or minus 22.3 pg/mL) and decreased during recovery to 137.8 plus or minus 15.9 pg/mL. The CSF NE level was higher in both groups than in patients with other neurological disorders. This may help explain the adrenergic signs observed during alcohol withdrawal.

Adult↗

GABA receptors are increased in brains of alcoholics.

gamma-Aminobutyric acid (GABA) receptor binding was increased in postmortem brain samples of chronic alcoholic patients compared to control patients. Numbers of binding sites were augmented in alcoholic brain, with no change in affinity. Muscarinic cholinergic and benzodiazepine receptors did not differ between controls and alcoholic brains, while a modest reduction in beta-adrenergic receptors may have been related to postmortem receptor changes. The results suggest that GABAergic mechanisms might play a role in chronic alcoholism.

Adult↗

Brain aldehyde dehydrogenase in human alcoholics and controls.

Human postmortem brain samples from temporal lobe of 23 alcoholics and 19 controls (13 with cancer and six without cancer) were used for determination of low Km (micromolar) and high Km (millimolar) aldehyde dehydrogenase activity. Despite histories of severe alcoholism leading to death through multiple complications, the mean values for either low or high Km activity did not differ significantly from that of controls similarly studied.

Adult↗

The carcinomatous neuromyopathy of oat cell lung cancer.

A prospective controlled clinical-neurophysiological-pathological study of 71 patients with oat cell carcinoma of the lung revealed no increased incidence of peripheral neuropathy at the initial stages of illness. All patients developed neuropathy by the time they had lost 15% of their body weight, but the neuropathy was less severe than in 20 age-matched alcoholic patients with an equal degree of weight loss. The weight loss and peripheral neuropathy progressed with atrophy of type II (adenosine triphosphatase-positive) muscle fibers out of proportion to the patient's loss of body weight. By 40% body weight loss, all the patients had moderate symmetrical peripheral neuropathy, 6 had proximal brachial or lumbosacral plexus metastases, and 9 had distal pressure palsies. Mononeuritis multiplex developed in only 1 patient, who had diabetes mellitus. Two patients developed Eaton-Lambert syndrome, which resolved in 1 when chemotherapy controlled the systemic tumor, with no protein in the tumor postmortem which could produce the characteristic electromyographic findings of the syndrome.

Adult↗

Effects of tetracycline on the streptococcal flora of periodontal pockets.

The effects of tetracycline on the subgingival streptococcal flora of periodontal patients were examined. Before antibiotic treatment, tetracycline-resistant isolates were obtained from 24 to 25 patients. In most patients, the proportion of the subgingival flora resistant to tetracycline increased after 2 weeks of therapy (1,000 mg of tetracycline/day) and then decreased after the cessation of treatment. Cultural conditions used for primary isolation were designed to favor the growth of facultative streptococci. Consequently, the majority (99%) of resistant isolates were identified as streptococci. Among 407 tetracycline-resistant Streptococcus isolates chosen for further classification, 9 species were identified, with S. sanguis (63%) and S. mitis (19%) predominating. There were no significant differences in the distribution of species isolated before and after treatment and after the cessation of tetracycline treatment. Plasmids were isolated from only 23 of 121 resistant streptococcal strains examined, suggesting that tetracycline resistance is not plasmid mediated in the majority of these oral streptococci.

DNA, Bacterial↗