6,7-Dihydroxytetrahydroisoquinoline: uptake and storage by peripheral sympathetic nerve of the rat.

6,7-Dihydroxy-1,2,3,4-tetrahydroisoquinoline is a pharmacologically active alkaloid that can be formed by condensation of dopamine with formaldehyde. We used fluorescence microscopy to study in vitro the uptake and storage of this compound by sympathetic nerves of the rat iris. Rats were treated with reserpine or with the methyl ester of alpha-methyl-p-tyrosine in order to deplete the endogenous catecholamine stores. Accumulation of the alkaloid was about onetenth that of norepinephrine. Uptake was completely blocked by 10-(5)M desmethylimipramine. These results offer some explanation for the sympathomimetric properties of the alkaloid. Similar results can be expected for similar tetrahydroisoquinolines that may be formed in vivo from endogenous catecholamines during ingestion of alcoholic beverages.

Cerebrospinal fluid methylmalonic acid levels in normal subjects and patients with cobalamin deficiency.

We measured methylmalonic acid, which accumulates in the blood and tissues of patients with cobalamin deficiency, in the CSF of 65 patients using capillary-gas chromatography and mass spectrometry. In 58 control patients, methylmalonic acid concentrations were always higher in CSF than in serum (mean CSF: serum ratio, 2.65; range, 1.17 to 7.78). In contrast, in six patients with elevated serum methylmalonic acid levels due to renal failure, CSF concentrations were normal in five and the CSF: serum ratio was less than one in four. In three patients with neuropsychiatric syndromes due to cobalamin deficiency and one patient with a normal serum cobalamin level who was an abuser of nitrous oxide, CSF concentrations were markedly increased (mean level, 600 times that of controls), out of proportion to those in the serum (mean CSF: serum ratio, 8.38; range, 3.5 to 13.5). The potential usefulness of CSF metabolite levels in the diagnosis of cobalamin deficiency is undetermined.

The role of bromocriptine in the treatment of parkinsonism.

Fifty-three patients with parkinsonism, either with intractable symptoms despite optimum-dosage levodopa therapy or with adverse effects from levodopa limiting its usefulness, were treated with bromocriptine, with gradually increasing doses until benefit or adverse effect was encountered. All were initially maintained on optimal levodopa therapy. Improvement was seen in 26 patients, of whom 19 (36 percent of the total 53 patients) had sustained improvement. Effective doses of bromocriptine ranged from 5 to 90 mg per day. Improvement occurred in all categories of clinical problems, including patients who lost some benefit from chronic levodopa therapy as well as those with adverse effects from levodopa. A high incidence (70 percent) of adverse effects of bromocriptine limited the usefulness of this drug. Since one cannot predict which patients might benefit from bromocriptine, this drug is worth a trial in patients not doing well on levodopa therapy if other means to improve their condition are not successful.

Analysis of the clinical problems in parkinsonism and the complications of long-term levodopa therapy.

We evaluated the current status of 131 patients with idiopathic parkinsonism who were receiving levodopa therapy. The residual parkinsonian symptoms and signs were tabulated, as were the adverse effects from medication. Response to therapy was correlated with duration of the disease and with duration of treatment. Patients with on-off or wearing-off effects were likely to have been treated for 4 years or longer. Patients treated with levodopa for 4 to 8 years were significantly more impaired with parkinsonism than patients treated for 0 to 3 years, even when patients were matched for total duration of disease. These data suggest that the deterioration of responsiveness after several years of levodopa therapy may be due to the therapy itself. Our findings support the concept that utilization of levodopa therapy should be delayed until a patient becomes significantly impaired in occupational or social situations.

Mycobacterium avium serotype 1 infection in a sandhill crane (Grus canadensis).

Tuberculous lesions were observed in the liver of an adult sandhill crane (Grus canadensis); Mycobacterium avium serotype 1 was isolated. Chickens inoculated intravenously with the culture had granulomas in the liver and spleen at necropsy 62 days after inoculation.

Drug eruption associated with sulfonamide treatment of vertebral osteomyelitis in a dog.

Drug eruption was diagnosed in a 4-year-old German Shepherd Dog being treated with sulfonamides for vertebral osteomyelitis due to infection with Nocardia spp. The eruption was characterized by generalized, pruritic, eczematous dermatitis. Diagnosis was based on a history of repeated exposure to sulfonamides, skin biopsy findingd, and clinical recovery on cessation of sulfonamide therapy.

Myopathies of the lower extremities.

The myopathies that can manifest themselves within the lower extremity are reported here and can serve as a guideline for clinicians in the early diagnosis of these disabling conditions. The classification of these disease entities based on signs and symptoms is significant if correlated with the age of the patient at the time of onset, the evolution and course, and the type of familial inheritance. This article can also aid the practitioner in assessing and planning the course of treatment for a particular patient.