PubMed Health⌕ Search

Biomedical subjects

T T Batchelor

Publications and source records attributed to T T Batchelor.

12 recordsLinked to original sources

Determination of procarbazine in human plasma by liquid chromatography with electrospray ionization mass spectrometry.

Procarbazine is a cytotoxic chemotherapeutic agent used in the treatment of lymphomas and brain tumors. Its pharmacokinetic behavior remains poorly understood even though more than 30 years have elapsed since the drug was approved for clinical use. To characterize the pharmacokinetics of procarbazine in brain cancer patients during a phase I trial, a method for determining the drug in human plasma by reversed-phase high-performance liquid chromatography (HPLC) with electrospray ionization mass spectrometry (ESI-MS) was developed and thoroughly validated. Plasma samples were prepared for analysis by precipitating proteins with trichloroacetic acid and washing the protein-free supernatant with methyl tert-butyl ether to remove excess acid. The solution was separated on a Luna C-18 analytical column using methanol-25 mM ammonium acetate buffer, pH 5.1 (22:78, v/v) as the mobile phase at 1.0 ml/min. A single-quadrupole mass spectrometer with an electrospray interface was operated in the selected-ion monitoring mode to detect the [M+H](+) ions at m/z 222.2 for procarbazine and at m/z 192.1 for the internal standard (3-dimethylamino-2-methylpropiophenone). Procarbazine and the internal standard eluted as sharp, symmetrical peaks with retention times (mean+/-S.D.) of 6.3+/-0.1 and 9.9+/-0.3 min, respectively. Calibration curves of procarbazine hydrochloride in human plasma at concentrations ranging from 0.5 to 50 ng/ml exhibited excellent linearity. The mean absolute recovery of the drug from plasma was 102.9+/-1.0%. Using a sample volume of 150 microl, procarbazine was determined at the 0.5 ng/ml (1.9 nM) lower limit of quantitation with a mean accuracy of 105.2% and an interday precision of 3.60% R.S.D. on 11 different days over 5 weeks. During this same time interval, the between-day accuracy for determining quality control solutions of the drug in plasma at concentrations of 2.0, 15 and 40 ng/ml ranged from 97.5 to 98.2% (mean+/-S.D., 97.9+/-0.4%) and the precision was 3.8-6.2% (mean+/-S.D., 5.1+/-1.2%). Stability characteristics of the drug were thoroughly evaluated to establish appropriate conditions to process, store and prepare clinical specimens for chromatographic analysis without inducing significant chemical degradation. The sensitivity achieved with this assay permitted the plasma concentration-time profile of the parent drug to be accurately defined following oral administration of standard doses to brain cancer patients.

Antineoplastic Agents↗

Primary nervous-system lymphoma.

Primary nervous-system lymphoma is a rare type of non-Hodgkin lymphoma, which is confined to the nervous system. This disease is managed quite differently from the usual treatment of either primary brain tumours or systemic non-Hodgkin lymphoma. Although whole-brain radiotherapy results in responses in more than 90% of cases, this treatment is associated with high relapse rates and with delayed neurotoxicity in elderly patients. First-generation chemotherapy regimens used successfully in systemic non-Hodgkin lymphoma (eg cyclo-phosphamide, adriamycin, vincristine, and prednisone) are ineffective in primary nervous-system lymphoma, partly because of the blood-brain barrier. Median survival of patients treated with radiotherapy alone or chemotherapy plus radiotherapy is similar, and ranges from 10 to 16 months. The addition of methotrexate-based chemotherapy has improved survival for these patients, extending median survival to more than 30 months. When used alone, methotrexate-based chemotherapy is associated with significantly fewer treatment-associated toxic effects. Leptomeningeal lymphoma and intraocular lymphoma are topics of particular relevance in primary nervous-system lymphoma and are addressed in this review.

Age Factors↗

Advances in the therapy of primary central nervous system lymphoma.

Primary central nervous system lymphoma (PCNSL) is a rare type of non-Hodgkin's lymphoma (NHL) confined to the nervous system. The management of PCNSL is quite different from the usual treatment of either primary brain tumors or systemic NHL. First-generation chemotherapy regimens used successfully in systemic NHL are ineffective in PCNSL, in large part due to the existence of the blood-brain barrier. Whole-brain radiation therapy (WBRT) results in high response rates but rapid relapse, and this treatment is associated with delayed neurotoxicity in patients with PCNSL. The addition of methotrexate-based chemotherapy has improved survival and lessened toxicity for this patient population. Fundamental issues that remain unresolved in PCNSL include identification of the optimal chemotherapy regimen for newly diagnosed and relapsed PCNSL, the role of WBRT and intrathecal chemotherapy in the treatment of PCNSL, and the optimal management of intraocular lymphoma. Finally, the optimal clinical study design for this rare disease has yet to be defined and implemented.

Brain Neoplasms↗

Solitary sciatic nerve lymphoma as an initial manifestation of diffuse neurolymphomatosis. Case report and review of the literature.

Solitary peripheral nerve lymphomas are exceedingly rare primary manifestations of diffuse peripheral nervous system or central nervous system (CNS) lymphomatosis. A 52-year-old man presented with progressive weakness in gastrocnemius and anterior tibial muscle function, which was associated with radiating pain in the right leg. Magnetic resonance imaging studies revealed a solitary fusiform tumor, extending from the sciatic nerve, at the level of the lesser trochanter of the femur, into the posterior tibial nerve below the popliteal fossa. Intraoperative gross examination found that the tumor diffusely expanded the nerve, but did not extend from or into surrounding muscle or tendons. The final histological diagnosis was a solitary extranodal lymphoma (Burkittlike high-grade B-cell lymphoma). Postoperative staging did not reveal evidence of lymphomatous involvement of other organs, but additional chemo- and radiotherapies were administered. Four months after the surgical biopsy, the patient presented with a right facial nerve palsy. The results of cytological examination of cerebrospinal fluid were positive for the presence of atypical lymphocytes, which was consistent with apparently progressive neurolymphomatosis; however, the results of radiological studies were negative for systemic progression. The patient underwent intrathecal chemotherapy followed by systemic myelosuppressive chemotherapy with bone marrow rescue, but died of respiratory failure while still receiving treatment. Postmortem examination revealed extensive lymphomatosis in the peripheral nerves and spinal nerve roots without evidence of cranial nerve, CNS, or other organ system involvement. The aggressive biological characteristics of these tumors, their management, and pertinent literature are reviewed.

Diagnosis, Differential↗

New treatment strategies for malignant gliomas.

Although survival in patients with malignant gliomas remains limited, there is renewed optimism with the emergence of novel treatment strategies. Cytotoxic agents such as temozolomide and CPT-11 have shown promising clinical activity. Biological treatments for brain tumors, including antisense oligonucleotides, gene therapy, and angiogenesis inhibitors, are also being evaluated in clinical trials. Delivery strategies have been developed to overcome challenges presented by the blood-brain barrier. These noteworthy treatments, alone or in combination, may ultimately prolong survival and enhance quality of life in this group of patients.

Antineoplastic Agents↗

Chorea as a paraneoplastic complication of Hodgkin's disease.

Neurologic complications of Hodgkin's disease (HD) include both metastatic and non-metastatic involvement of the nervous system. There are at least five paraneoplastic syndromes associated with HD but chorea has not been described. We report the first choreiform disorder as a paraneoplastic complication of HD and only the second case of paraneoplastic chorea in the literature.

Aged↗

Immunoadsorption therapy for paraneoplastic syndromes.

Paraneoplastic neurologic syndromes associated with systemic cancer are being increasingly recognized. Although these syndromes are thought to be immunologically mediated treatment with steroids, immunoglobulin and plasmapharesis has been disappointing. Based on our preliminary experience with the treatment of 6 cases of paraneoplastic neurologic syndromes with protein A immunoadsorption, an institutional, open-arm treatment protocol was established. Since our original report we have treated an additional 7 patients with this method. The 13 cases were accrued over a 2 year period and included 10 women and 3 men with an average age of 63. The paraneoplastic syndromes included 6 cases of cerebellar degeneration, 3 cases of opsoclonus/myoclonus, 3 cases of encephalomyelitis and 1 case of Lambert Eaton myasthenic syndrome. Primary cancers included 4 cases of small cell lung cancer, 2 cases of breast cancer, 2 cases of lymphoma and 1 each of acinic cell cancer, cholangiocarcinoma, Merkel cell cancer, pancreatic adenocarcinoma and rectal cancer. Anti-neuronal antibody status, cerebrospinal fluid and neuroimaging studies as well as cancer staging and treatment protocols were reviewed. Neurologic syndromes were clinically separated into component symptoms and signs for assessment of treatment effect. The treatment goal was a total of 6 sessions of protein A immunoadsorption given twice weekly. Twelve of 13 patients completed therapy and one patient developed cutaneous vasculitis during the second session with termination of treatment. Of the remaining patients 3/12 had a complete response of the primary clinical symptom/sign while 6/12 had a partial response for a total response rate of 9/12 (75%). Toxicity was limited to cutaneous vasculitis in 1 patient and an episode of hemisensory changes in another patient. Current treatment of paraneoplastic neurologic syndromes remains unsatisfactory. Despite the small number of patients in this report, protein A immunoadsorption is a promising therapy which deserves further study in a larger population of patients with paraneoplastic syndromes.

Adsorption↗

Neuroimaging abnormalities with hypoglossal nerve palsies.

Seven patients with acute or chronic unilateral hypoglossal nerve lesions were evaluated by magnetic resonance imaging and computed tomography. In the patients with acute to subacute paralysis of the tongue, the base of the ipsilateral side of the tongue appeared expanded with increased signal intensity on T2-weighted images. This appearance suggested an infiltrative mass lesion within the tongue. These radiographic findings are due to the pathophysiological process of nerve injury and muscle denervation.

Adult↗

Steroid myopathy in cancer patients.

We prospectively evaluated 15 adult cancer patients being treated with adrenocorticosteroids (steroids) to determine the frequency and time course of "steroid myopathy." Nine (60%) developed clinically detectable proximal muscle weakness that, in six, was severe enough to interfere with activities of daily living. Proximal muscle weakness developed within 15 days in eight of nine patients and was significantly related to the cumulative dose of steroid. Eight of nine patients with proximal muscle weakness, and two of six without such weakness, experienced a significant decline in respiratory function, leading to symptomatic dyspnea in four patients of the former group. In three patients who could be followed for more than 3 months off steroids, there was either improvement or resolution of the weakness and, when present, of the respiratory impairment. Steroid myopathy is a common complication among cancer patients receiving steroids. It can often affect respiratory function even when proximal limb muscles remain strong. Clinical recognition is important since steroid myopathy can lead to increased morbidity and may be reversible with reduction or discontinuation of steroids.

Adult↗

Neuroimaging abnormalities with hypoglossal nerve palsies.

Seven patients with acute or chronic unilateral hypoglossal nerve lesions were evaluated by magnetic resonance imaging and computed tomography. In patients with acute to subacute tongue paralysis, the base of the ipsilateral side of the tongue appeared expanded and showed increased signal intensity on T2-weighted images. This appearance was suggestive of an infiltrative mass lesion within the tongue. These radiographic findings are due to the pathophysiological process of nerve injury and muscle denervation.

Acute Disease↗