PARANEOPLASTIC OPTIC NEUROPATHY AS AN INITIAL CLINICAL MANIFESTATION OF SMALL CELL LUNG CANCER. A CASE REPORT.

Paraneoplastic optic neuropathy (PON) is a very rare condition. In this study, a case of PON whose first complaint was painless vision loss in one eye is presented. In the follow-up of our case, optic neuropathy developed in the fellow eye. Electromyography examination performed due to diffuse body pain and motor loss in the left extremity is compatible with peripheral sensorimotor polyneuropathy. Lung biopsy was planned due to EMG result and and lymphadenopathy detection in thorax computed tomography (CT). The biopsy result of the patient was reported as nonspecific hyperplasia. As the patient's complaints increased, the paraneoplastic antibody panel was requested and CV2 / CRMP5 antibody was found positive. Thereupon, as a result of repeated biopsy, our patient was diagnosed with small cell lung cancer. We think that paraneoplastic optic neuropathy should be considered in the differential diagnosis in patients with advanced age, smoking, painless subacute vision loss, optic disc swelling, and we should insist on research in this direction as in our case.

Evidence for neurotoxicity associated with amoxicillin in juvenile rats.

Amoxicillin (AMX) is one of the most commonly prescribed antibiotics for children, and childhood is the period to have the highest risk for toxicity cases including drug-induced adverse reactions. Some neurological adverse effects (anxiety, hyperactivity, confusion, convulsions, and behavioral changes) have been reported related to AMX treatment. In the present study, we aimed to determine the neurotoxic effects of AMX administration at clinically relevant doses in female juvenile rats. AMX was administered in single oral daily doses of 25 and 50 mg/kg for 14 days. According to our results, while AMX administration caused a significant increase in the immobility time of animals, swimming time of these animals significantly decreased. AMX administration significantly reduced the onset of pentylenetetrazole-induced convulsions. The serotonin levels of brain tissues in the AMX-administered groups were decreased significantly, which is thought to be related to depression. The glutamate levels in brain tissues increased significantly in AMX-administered groups, which is thought to be related to convulsion. Otherwise, superoxide dismutase and catalase activities were significantly decreased in brain tissues of AMX-administered groups. In conclusion, AMX administration triggered depression and shortened the time of the appearance of first seizure in juvenile rats. Also, altered brain neurotransmitter levels and increased oxidative stress observed in our study were thought to be the possible underlying mechanisms of AMX-induced neurotoxicity.

Single right coronary artery-R-I subtype: a report of an extremely rare case.

A single coronary ostium with no associated congenital cardiac disease is a rare congenital coronary-artery anomaly. However, a single right coronary artery has a much rarer incidence. We report here the antemortem diagnosis of a case with R-I subtype single coronary artery supplying the entire myocardium. A 36-year-old female with chest pain and dyspnea on exertion was admitted to the hospital, whose coronary angiography revealed a single, large coronary artery originating in the right aortic sinus. No observable change was detected in her electrocardiogram and her angiographic examination did not reveal any significant luminal narrowing although she experienced chest pain and dyspnea on exertion. R-I type of single coronary artery is an anomaly with a very rare incidence, which may cause myocardial ischemia and sudden death and whose recognition might be of use to physicians when diagnosing and treating this anomaly.

The role of L-arginine/nitric oxide pathway in the antinociceptive activity of pyridoxine in mouse.

In the present study the role of L-arginine/nitric oxide (NO)/cGMP pathway in the antinociceptive activity of pyridoxine in p-benzoquinone-induced abdominal constriction test in mouse was investigated. Pyridoxine (CAS 58-56-0) displayed dose-dependent antinociceptive activity at 0.0625-1 mg/kg (s.c.) doses. L-arginine (CAS 1119-34-2), a NO precursor, displayed a triphasic pattern as antinociception-nociception-antinociception (61.8 +/- 7.8, -36.5 +/- 12.7 and 17.0 +/- 4.3%, 5, 40 and 50 mg/kg, s.c., respectively). The antinociceptive effect of pyridoxine at ED50 dose (0.43 mg/kg, s.c.) (47.7 +/- 3.9%) was significantly decreased by L-arginine at 40 and 50 mg/kg doses (4.1 +/- 9.3 and 37.8 +/- 1.6%, respectively) while 5 mg/kg dose of L-arginine significantly potentiated the pyridoxine analgesia. On the other hand, pyridoxine reversed the L-arginine-induced nociception to antinociception (4.1 +/- 9.3%) and augmented the antinociceptive effect of L-arginine (37.8 +/- 1.6%). L-NG-nitroarginine methyl ester (CAS 51298-62-5), a NO synthase inhibitor, at 75 mg/kg, s.c. produced antinociception and significantly increased the antinociceptive effect of pyridoxine (63.7 +/- 1.2%). Methylene blue (CAS 61-73-4, MB), a guanylyl cyclase and/or NO synthase inhibitor, was antinociceptive and nociceptive at 5 and 40 mg/kg doses, respectively, 5 mg/kg dose of MB significantly increased the antinociceptive effect of pyridoxine, but did not change it at 40 mg/kg dose. On the other hand, pyridoxine significantly decreased the antinociceptive effect of MB and reversed the MB-induced nociception to antinociception. Combination of pyridoxine and morphine (CAS 57-27-2) (ED50: 0.13 mg/kg, s.c.) at 49.8 +/- 1.9% revealed a significant antinociceptive potentiation (69.1 +/- 1.8%). The findings of the present study emphasise the contribution of central and/or peripheral L-arginine/NO/cGMP nociceptive processes in pyridoxine-induced antinociception.

Coronary artery bypass grafting nine months after pneumonectomy.

We performed coronary artery bypass grafting on a 58-year-old man who only 9 months earlier had undergone right pneumonectomy for bronchial carcinoma. Although his preoperative pulmonary function had been poor, coronary artery bypass surgery was successful, and the patient was discharged on the 9th postoperative day Two years after surgery, he remained in New York Heart Association functional class I. We attribute this success to special management before, during, and after the operation. On the 32nd postoperative month, this patient died of multiple tumor metastases.

Participation of the components of L-arginine/nitric oxide/cGMP cascade by chemically-induced abdominal constriction in the mouse.

The purpose of this study was to investigate the role of the L-arginine/nitric oxide (NO)/cGMP pathway in p-benzoquinone-induced writhing model in mouse. L-arginine, a NO precursor, displayed antinociceptive effects at the doses of 0.125-1.0 mg/kg. When the doses of L-arginine were increased gradually to 10-100 mg/kg, a dose-dependent triphasic pattern of nociception-antinociception-nociception was obtained. The NO synthase (NOS) inhibitor, NG-nitro-L-arginine methyl ester (L-NAME) (18.7515 mg/kg), possessed antinociceptive activity. Methylene blue (MB), a guanylyl cyclase and/or NOS inhibitor, (5-160 mg/kg) also produced a dose-dependent triphasic response. When L-arginine (50 mg/ kg) was combined with L-NAME (75 mg/kg). L-arginine-induced antinociception did not change significantly. Cotreatment of L-arginine with 5 mg/kg MB significantly decreased MB-induced antinociception and reversed the nociception induced by 40 mg/kg MB to antinociception. It is concluded that the components of L-arginine/nitric oxide/cGMP cascade may participate in nociceptive processes both peripherally and centrally by a direct effect on nociceptors or by the involvement of other related pathways of nociceptive processes induced by NO.