Biomedical subjects

Morvarid Karimi

Publications and source records attributed to Morvarid Karimi.

3 recordsLinked to original sources

PubMed2006

Modified high-performance liquid chromatography with electrochemical detection method for plasma measurement of levodopa, 3-O-methyldopa, dopamine, carbidopa and 3,4-dihydroxyphenyl acetic acid.

Plasma measurements of levodopa and its major metabolites including dopamine and 3-O-methyldopa have been limited by cumbersome methods and poor sensitivity within relatively narrow ranges of plasma levels. We now report a modification of an HPLC method that permits concomitant measurements of a wide range of concentrations of levodopa, dopamine (DA), carbidopa, 3-O-methyldopa (3-OMD) and 3,4-dihydroxyphenyl acetic acid (DOPAC) from one HPLC injection. The recoveries ranged from 77 to 107% with an intra-day precision around 5% (CV) and inter-day CV's about 10-20%. This validated method will simplify pharmacokinetic studies of levodopa and its metabolites for mechanistic studies or therapeutic clinical monitoring which play a crucial role in development of strategies to prolong motor benefits from individual doses and reduce involuntary movements called dykinesias.

3,4-Dihydroxyphenylacetic Acid↗

PubMed2006

Relative risk of spread of symptoms among the focal onset primary dystonias.

Adult-onset primary torsion dystonia (PTD) may spread to multiple body parts, but the relative risk of spread by site of onset of dystonia has not been well characterized. We retrospectively identified 602 patients with PTD out of 1,500 dystonia patients in our electronic database and extracted age at onset, site of onset, family history, and spread. Survival analyses were performed for groups based on site of onset, and hazard ratios compared relative risk of spread across groups. Patients with adult-onset blepharospasm were more likely to spread (31% past the head) than those with dystonia starting in the neck (9%), larynx (12%), or upper extremities (16%). Hazard ratios proved that the blepharospasm group had the greatest relative risk of spread. The rate of spread after onset varied significantly between the different groups. Most spread occurred in the first 1 to 2 years after onset of blepharospasm, whereas the risk of spread was relatively constant over time in cervical and laryngeal dystonia. Different sites of onset of PTD confer different risks of spread, important for clinical prognosis. Different risks of spread may provide clues about underlying pathogenesis of adult-onset primary dystonias.

Adult↗

PubMed2004

Rubral lateropulsion due to vertebral artery dissection in a patient with Klippel-Feil syndrome.

BACKGROUND: Neurologic deficits in patients with Klippel-Feil syndrome usually are attributed to direct compression of neuronal structures or hypoperfusion secondary to compression of the vertebral arteries by bony abnormalities. OBJECTIVE: To describe a 38-year-old woman with known Klippel-Feil syndrome who developed lateropulsion. RESULTS: The results of magnetic resonance imaging were consistent with rubrothalamic stroke. The cerebral angiogram confirmed vertebral artery dissection at the level of her previously observed bony abnormality. CONCLUSIONS: Hypermobility adjacent to fused vertebrae subjects the vertebral artery to increased shear forces. Thus, Klippel-Feil syndrome may be a predisposing factor for vertebral artery dissection. Moreover, to our knowledge, this case represents the second known case of rubral lateropulsion.

Adult↗