Chronological observation in early radiation myelopathy of the cervical spinal cord: gadolinium-enhanced MRI findings in two cases

Gd-enhanced MR images of two patients with clinically and histopathologically diagnosed chronic progressive radiation myelitis (CPRM) were observed chronologically. One of them had had nasopharyngeal cancer and received radiotherapy at a dose of 100 Gy to the C1-2 level of the spinal cord. She developed CPRM 25 months after the termination of radiotherapy. The other had had malignant lymphoma originating from the tonsil and received chemoradiotherapy. The dose delivered to her cervical spinal cord was 40 Gy, and she developed CPRM 30 months later. Gd-enhanced MRI in the early phase revealed a small crescent-shaped nidus with or without a very small central nonenhanced area in both cases. Enhancement was not great. At that time, patients noticed only the inability to perceive pain and temperature or paresthsia in the opposite side. In a few months, MRI revealed a much more strongly enhanced and larger nidus with enlargement of a central nonenhanced area accompanied by long segmental cord enlargement. The patients' neurological symptoms had also progressed, with hemiparesis developing, for example.

[Effect of intraocular irrigating solution on electroretinogram during pars plana vitrectomy]

The effects of intraocular irrigating solutions on the human retina are not known. We recorded 30 Hz-flicker electroretinograms (ERGs) during vitrectomy, and examined the effects of perfusate S-MA2 and DE-057 on the human ERG. The amplitude of the 30 Hz-flicker ERGs were not significantly different for the two irrigating solutions. The peak latency of the 30 Hz-flicker ERG was increased 14 +/- 4.4% (mean +/- SE) during irrigation with S-MA2, compared with the preoperative peak latency. Replacement of S-MA2 by DE-057 increased the peak latency by 37 +/- 5.8% (p < 0.01). Since the peak latency of the 30 Hz-flicker ERG became shorter after replacement of DE-057 by S-MA2, these effects were reversible (p < 0.01).

[A case report of bone metastasis diagnosed by MRI and effectively treated with UFT after breast conserving therapy for breast cancer]

A 66-year-old woman with left breast cancer (medullary carcinoma; T1cN1M0; Stage II A) was treated with breast conserving therapy combined with lumpectomy, radiotherapy, chemotherapy and endocrine therapy beginning in March, 1990. She complained of back pain and was diagnosed as having bone metastasis to the lower thoracic spine by bone scintigram and MRI examination in September, 1990. Oral administration of UFT (300 mg/day) was started, and 5 months later, back pain disappeared; nineteen months later, no definite findings of bone metastasis were observed on bone scintigram and MRI. It was concluded that long-term oral administration of UFT is an effective remedy for bone metastasis after breast conserving therapy for breast cancer.

[A study of irradiated spines in radiotherapy--using 99mTc-HMDP bone scintigraphy & MR imaging]

When radiation therapy is performed on a patient with malignant tumor, vertebral spines are sometimes included in the irradiation field. In the present study, 99mTc-HMDP uptake was examined in 102 cases of malignant tumors treated with radiation therapy (irradiated total doses from 10 to 70 Gy) in order to clarify the time course of accumulation. The scintigram on the film was transformed with a film digitizer into objective data, and the Accumulation Decreasing Index (ADI) was calculated each month after irradiation. In the group receiving less than 30 Gy, recovery of 99mTc-HMDP accumulation was seen after a mild decrease in the ADI. However, in the group that received more than 40 Gy, no recovery of accumulation was seen, and a large decrease in the ADI followed. Vertebral MRI was performed with and without Gd-DTPA enhancement to calculate the vertebral Signal Intensity Ratio (SIR), and decreased blood flow in the irradiated bone marrow was estimated from the changes in SIR values. In the irradiated area, no definite abnormal accumulation of 99mTc-HMDP was observed against the new metastatic bone tumor. In such cases, MRI should be performed soon after bone scintigraphy in order to detect the tumor.

[Effect of metoclopramide, dopamine receptor blocker, on the EOG light peak]

We studied the effects of metoclopramide hydrochloride (MTCL), a D2-selective dopamine receptor antagonist, on the electro-oculograms (EOGs) in 10 eyes of 5 healthy volunteers and on the electroretinograms (ERGs) in 6 eyes of 3 volunteers. MTCL was given intravenously after 15 minutes of dark adaptation. The L/D ratio of EOG was 2.13 +/- 0.14 (mean +/- SE) before the administration of MTCL. After the administration of MTCL, the dark-adapted EOG amplitudes increased transiently. MTCL significantly depressed the L/D ratio to 1.60 +/- 0.07 (p less than 0.01). The a- and b-wave amplitudes of the flash ERG decreased by 12% and 11% respectively. However, the OP2 and OP3 amplitudes of oscillatory potential increased by 23% and 19% respectively. The implicit times of all waves mentioned above tended to be prolonged. This study shows that a blockade of D2-dopamine receptor supresses the EOG light peak. Further investigations are needed to clarify the exact mechanism of this effect.

Characterization of magnesium dependent adenosine 5'-triphosphatase in bovine brain cytoplasmic dynein

The Mg2(+)-ATPase activity of cytoplasmic dynein isolated from bovine brain was examined in the absence of microtubules. Cytoplasmic dynein in the absence of microtubules showed Mg2(+)-ATPase activity with two distinct Km values, 272 microM and 11.8 microM. The initial burst of Pi liberation, which was due to occurrence of slow decomposition of reaction intermediate, was 0.67 mol per mol of cytoplasmic dynein. These results indicate that Mg2(+)-ATPase reaction of cytoplasmic dynein in the absence of microtubules is similar to that of flagellar and ciliary dyneins which have been shown not to hydrolyze ATP via a single pathway.

Clinical studies on the occurrence and the pathogenesis of optociliary veins

We reviewed retrospectively 20 cases of optociliary vein over the past 5 years. Fifteen of the 20 cases (75%) were over 40 years of age. There was no sex differences (9 males and 11 females). Causative ocular diseases were: central retinal vein occlusion (14 cases, 70%); optic disc drusen (2 cases, 10%); and optic nerve sheath meningioma, high myopia, glaucoma, congenital anomaly (1 case each, total 20%). The number of patients with an optociliary vein was high in central retinal vein occlusion (14/190 cases, 7.4%). We concluded that occurrence of optociliary vein is not restricted to cases with optic nerve sheath meningioma and this shunt vessel may occur under other conditions in which central retinal venous return is seriously disturbed. The most common cause of optociliary vein is central retinal vein occlusion.

Atypical nerve fiber layer defects in high myopes with high-tension glaucoma

The incidence of atypical optic nerve head and retinal nerve fiber layer defects was studied in 61 high myopic eyes (greater than or equal to -5 diopters) and 91 emmetropic or hyperopic eyes (0 to +3 diopters) of 152 patients with chronic high-tension glaucoma, and in 45 control myopic eyes (greater than or equal to -5 diopters). Horizontal ovalness or cyclotorsion, oblique insertion of the optic disc, and bean pot disc were more common in the high myopes. In the eyes with high myopia with glaucoma, inferior dominant nerve fiber layer defects, ectopic fiber defects, and multiple nerve fiber layer defects were common. The incidence of superior nerve fiber layer defects or superior-inferior equal nerve fiber layer defects was high in round or vertically oval discs and low in cyclotorted or horizontal oval discs. The oblique insertion of the discs correlated positively with a higher incidence of ectopic defects in high myopic eyes with glaucoma. The incidence of focal type nerve defects is higher in older patients and high myopes with oblique insertion of the optic disc. Atypical shape of the optic disc correlates positively with atypical retinal nerve fiber layer defects in eyes with high-tension glaucoma.

Axonal transport in mdx mouse sciatic nerve

Anterograde and retrograde flows of acetylcholinesterase (AChE) in sciatic nerves of adult mdx mice were compared with those of normal mice. Specific molecular forms of AChE were resolved by high-performance liquid chromatography such that slow anterograde (G1 + G2), fast anterograde and fast retrograde (G4 and A12) flows could be simultaneously studied. Although we found no difference in the total AChE activity and the molecular forms in non-ligated nerves between mdx and the normal mice, ligated nerves showed significant differences. The total AChE activity accumulated at the proximal segment of ligated nerve was higher in mdx mice than in normal mice after 24 h ligation. The G1 + G2 molecular forms were accumulated more in the proximal segment of mdx than the normal. A12, on the other hand, was more abundant in both segments of mdx mice than the normal. No statistically significant difference in the accumulated amount of G4 molecular form was present between mdx and the normal mice at either proximal or distal segment. These results indicated that axonal flow in sciatic nerve likely plays a role in muscle regeneration, and that the transport machinery in dystrophin-deficient mdx neuron is probably normal.

[Study on suppressed uptake by the liver in 67Ga scintigraphy]

During the past 3 years, we have performed 1525 studies of 67Ga scintigraphy and 38 cases of these showed suppressed liver uptake; 19 cases after chemotherapy, 13 cases with liver dysfunction and 6 cases with competitive blockade. Many cases in chemotherapy used cyclophosphamide and vincristine, and were performed 67Ga scan within 1 week after chemotherapy. In cases showed suppressed uptake by liver after chemotherapy, serum Fe was markedly increased and UIBC was markedly decreased (p less than 0.01). This suggested that serum Fe influenced suppressed uptake by liver more than carrier-protein, disturbed hepatic cells, and receptors.