[Causes of visual field defects after vitrectomy].

PURPOSE: An inferotemporal visual field defect sometimes occurs following vitreous surgery for idiopathic macular hole. There is a possibility that this visual field defect is due to damage to the superonasal retina by fluid or air irrigation through an inferonasal infusion port. We tested this hypothesis by placing the infusion port in the inferonasal sector during vitreous surgery. CASES AND METHOD: We performed vitreous surgery on 31 eyes with idiopathic macular hole. The infusion port was placed in the inferonasal sector. The vitreous cavity was replanced either by 20% SF6 or 12% C3F8. We did not abrade the retinal pigment epithelium within the hole. The visual field was assessed before and 1 month after surgery using a Goldmann perimeter. FINDINGS: Three eyes developed a wedge-shaped visual field defect in the inferonasal sector. No visual field defect developed in the other 28 eyes. CONCLUSION: The findings show that visual field defect following surgery for idiopathic macular hole is dependent upon the site of the infusion port. We presume that the visual field defect is consequent to retinal damage caused by the flow of air or fluid during surgery.

A chicken monoclonal antibody with specificity for the N-terminal of human prion protein.

Chickens were immunized with human prion protein (PrP) peptide H25 (amino acid residues 25-49) coupled to keyhole limpet hemocyanin. From a fusion experiment using the chicken fusion partner cell line MuH1 and immune spleen cells, one mAb, HUC2-13, was generated which reacted with the peptide. HUC2-13 was specific for a pentapeptide (RPKPG) of the N-terminal of the peptide H25. In Western blotting analysis, the mAb reacted with PrP materials from a human Creutzfeldt-Jakob disease (CJD) case and the membrane fraction from normal murine brain, but not with the same materials pretreated with proteinase K. When compared with the HUC2-13 and the conventional mouse mAb 3F4, the background stainings using the HUC2-13 were minimal. In immunohistochemistry, the HUC2-13 stained positively with kuru plaques in brain sections from patients with Gerstmann-Straussler syndrome (GSS), and also reacted with synaptic structures of the CJD patients. However, any immunolabelings using the HUC2-13 were not observed in the section from a patient with amyotrophic lateral sclerosis (ALS) as CJD-negative control. These results indicate that the mAb HUC2-13 is a suitable tool for immunological and diagnostic analyses of prion disease in humans and other mammals.

[Clinical characteristics of pulmonary embolism without definitive predisposing factors].

Patients with pulmonary embolism may have no definitive predisposing factors for thrombi. The clinical entity of chronic pulmonary embolism is also uncertain. This study clarified the clinical characteristics of pulmonary embolism without definitive predisposing factors. During the last 10 years, 36 consecutive patients were diagnosed as having pulmonary embolism (mean age 61 years, female 75%). Twenty-four patients (67%) had definitive predisposing factors ("definitive" group). Patients without definitive predisposing factors had the following characteristics. The onset of symptoms was out-hospital and insidious. The main symptom was exertional dyspnea without acute episode compatible with an embolism. In four patients (33%) there was a delay of over 2 years form the onset of symptoms to the diagnosis. Three patients had been treated for depression. Thrombolytic therapy caused an inadequate fall in mean pulmonary artery pressure from 41 +/- 11 to 24 +/- 8 mmHg and in three patients it remained over 30 mmHg. Deep vein thrombosis were found in four of nine patients in whom venography were performed 10 days after thrombolytic therapy, but only one patient showed thrombus in the "definitive" group. During the convalescent stage, all patients were treated with prophylactic warfarin. Home oxygen therapy was indicated in three patients and an inferior vena caval filter was implanted in two patients. One third of patients with pulmonary embolism in our institute had no definitive predisposing factors. In these patients, even with thrombolytic therapy, recovery of pulmonary hypertension was often insufficient and deep vein thrombosis persisted. Clinicians should be aware of this disease to avoid undue delay in its diagnosis.

Surgical removal of submacular hemorrhage using tissue plasminogen activator and perfluorocarbon liquid.

PURPOSE: To assess the result of surgical removal of submacular hemorrhage by using tissue plasminogen activator and perfluorocarbon liquid. METHODS: In 22 consecutive patients (22 eyes), subretinal hemorrhage associated with age-related macular degeneration, which involved the fovea and completely obscured the choroidal vascular pattern, was treated by pars plana vitrectomy. The hemorrhages were liquefied with tissue plasminogen activator, squeezed into the vitreous cavity with perfluorocarbon liquid, and then evacuated. RESULTS: Efficacy of the procedure was judged by the best postoperative corrected visual acuity, which was 20/100 or better in 16 eyes (73%). Submacular hemorrhage recurred in four (18%) eyes, epiretinal membrane formed in three (14%) eyes, and retinal detachment occurred in three (14%) eyes. Best-corrected final visual acuity was improved postoperatively in 18 (82%) of the 22 eyes, unchanged in three (14%) eyes, and decreased in one (5%) eye, final visual acuity was 20/200 or better in 15 eyes (68%) and limited in other eyes by subretinal hemorrhage of greater than 30 days' duration or subfoveal neovascularizations. CONCLUSIONS: Use of tissue plasminogen activator and perfluorocarbon liquid in surgical removal of submacular hemorrhage may improve the outcome of surgery by reducing surgically induced retinal damage.

[Visual functional changes in idiopathic macular holes treated by vitrectomy].

We evaluated visual functional measurements, visual acuity, central retinal sensitivity in a Humphrey field analyzer, and binocular function in Stereotest, Amsler grid testing, of 51 idiopathic macular holes before and after vitrectomy. In 36 of 51 eyes (71%) where the macular hole was closed after vitrectomy, there were improvements in all visual functional measurements postoperatively. The eyes in which the macular hole was closed had significantly better visual acuity before vitrectomy than those in which the hole was not closed. In 16 of 51 eyes that had visual acuity of less than 20/200 preoperatively, central retinal sensitivity before vitrectomy was higher in the eyes where the macular hole was closed than in those in which it was not closed. These measurements are useful for evaluation of visual functional improvements after vitrectomy and can help to choose candidates for macular hole surgery.

Insertion sequence IS6100 on plasmid pOAD2, which degrades nylon oligomers.

The nucleotide sequence of repeated sequence I, which appears in five regions on nylon oligomer-degrading plasmid pOAD2, harbored in Flavobacterium sp. strain K172, was determined. The five regions of repeated sequence I had 880 bp of identical sequence, and the sequence was identical to that of IS6100, an insertion sequence classified in the IS6 family, initially found in Mycobacterium fortuitum. Sequences homologous to that of IS6100 were found for another nylon oligomer-degrading plasmid, pNAD2, harbored in Pseudomonas sp. strain NK87, by Southern hybridization experiments.

[The prediction of blood pressure after adrenalectomy in primary aldosteronism].

In 30-40% of patients with primary aldosteronism owing to adenoma, hypertension is not relieved even though a hyper-functioning adenoma has been completely removed. The purpose of this study is to determine whether the prognosis of hypertension can be evaluated pre-operatively in patients with primary aldosteronism. Thirteen patients (6 men, 7 women; 47 +/- 9 years old) with primary aldosteronism were studied and adrenalectomy was performed in all cases. The success of the operation was confirmed by the normalization of plasma renin activity (PRA), plasma aldosterone concentration (PAC) and serum potassium. Eight patients, 3 men and 5 women, whose blood pressure (BP) was reduced to below 140mmHg systolic and 90mmHg diastolic at one year after the operation were classified as "group N" and the other 5 cases, 3 men and 2 women, remained hypertensive and were classified as "group H". There were no significant differences in the age of the patients, duration of hypertension, pretreatment mean BP and severity of hypertension between the two groups. Thus, it is doubtful that the lack of improvement of hypertension is due to the irreversible damage of the small arteries. Although pretreatment BP was similar in the two groups, systolic BP after the administration of 200mg per day of spironolactone for one week was significantly reduced in group N, but not in group H. Moreover, a significant correlation was found between mean BP after treatment with spironolactone and post-operative mean BP in all subjects. Pretreatment PRA was significantly lower in group H.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of moderate hypercapnia on hypothermia induced by cold He-O2 in rats.

1. Effects of moderate hypercapnia (10% CO2) on rectal temperature, oxygen consumption and body weight loss were examined during and after acute hypothermia induced by cold and helium-oxygen. 2. Hypothermia induction time was reduced significantly by hypercapnia. Rewarming tended to be faster in hypercapnic animals than in normocapnic animals. 3. Hypercapnia significantly reduced body weight loss when measured during hypothermia and during normothermia after rewarming. 4. Oxygen consumption during cooling was decreased by hypercapnia. 5. Exposure to 10% CO2 during cooling may spare energy substrate and favor survival in hypothermia.

Intracellular sodium and potassium concentrations in erythrocytes of patients with primary aldosteronism.

Intracellular concentration of sodium ([Na]i) and potassium ([K]i), and the ouabain sensitive sodium efflux rate constant (ERCos) in erythrocytes were determined in patients with primary aldosteronism, before and after the surgical removal of the adrenocortical adenoma and in comparison to those in healthy controls. Without treatment, [Na]i was higher and ERCos was lower in patients with primary aldosteronism than in controls (10.60 +/- 0.96 vs. 8.25 +/- 0.89 mmol/l cells, p less than 0.01; 0.156 +/- 0.040 vs. 0.255 +/- 0.047/hour, p less than 0.01, respectively). After the surgery, [Na]i was decreased to 7.70 +/- 0.64 mmol/l cells and ERCos was increased to 0.273 +/- 0.031/hour and these values were similar to those in controls. [K]i in primary aldosteronism was not affected by the surgery (from 96.79 +/- 2.03 to 98.8 +/- 3.84 mmol/l cells) and was not different from that in controls (99.11 +/- 3.42 mmol/l cells). In 2 patients, normalization of the serum potassium following an oral potassium chloride supplement caused only partial improvement in [Na]i and ERCos. These results suggest that an inhibition of sodium pump activity resulting in elevated [Na]i may play an important role in the pathogenesis of high blood pressure in patients with primary aldosteronism.

Effects of a high concentration of CO2 on electrocardiograms in the carp, Cyprinus carpio.

1. The effects of a high concentration of CO2 (PCO2 = 250 mmHg and PO2 = 360 mmHg in water) and MS222 (tricaine methanesulfonate, 1/8000 or 1/5000) on the electrocardiogram (ECG) in carp were examined using five kinds of bipolar leads from the body surface. 2. In the carp anesthetized with the high concentration of CO2 for 30 min, the QRS duration, PQ interval and and direction of the QRS axis on the frontal plane significantly changed. Even after recovery from anesthesia, delay in the QRS duration was still recognized. 3. The concentration of CO2 used in this study had an anesthetic action to the same degree as 1/8000 of MS222 and had a much more severe effect on the ECG of the carp than 1/5000 of MS222.

Electrocardiograms in five bipolar leads recorded from the body surface of three fish species (Cyprinus carpio, Oreochromis niloticus and Pagrus major) in fresh or sea-water.

1. ECGs were recorded using five bipolar leads from the body surface of porgy Pagrus major and tilapia Oreochromis niloticus in fresh or sea-water, or held on a dry towel. 2. The maximum QRS amplitude was detected in lead V in both species being 54 +/- 25 microV in porgy and 241 +/- 78 microV in tilapia, respectively, when the fish were held on the dry towel. 3. Clear ECG waves could not be obtained from porgy in sea-water because of the porgy's small cardiac potential and leakage of the potential. However, clear ECG waves could be obtained in sea-water from the body surface of tilapia, with the average QRS amplitude being 35 +/- 8 microV. 4. The mean electrical P and QRS axes in tilapia were directed toward almost the same direction (frontal downward), whereas both P and QRS axes in most carp were in opposite directions. In porgy, the relationship between the P and QRS axes could not be identified due to the smaller amplitude of the P wave.

Electrocardiograms recorded from the body surface of the carp, Cyprinus carpio.

The electrocardiograms (ECGs) in five kinds of bipolar leads were recorded from the body surface of the carp under water. Each component constituting the ECG wave could be detected by the present method. The potentials of the ECGs recorded by the present method were relatively small, the values being 2-64 microV. The electrical axis in most carp was directed toward the right lateral side.

Possibility of 2,4,5-triamino-6-hydroxypyrimidine as an intermediate in the pathway of riboflavin biosynthesis.

It was studied with resting cells of a high flavinogenic mold, Eremothecium ashbyii, whether or not 2,4,5-triamino-6-hydroxypyrimidine (THP) is an intermediate in the early pathway of riboflavin biosynthesis. A small amounts of THP strongly inhibited riboflavin formation in the resting cells, but the inhibition was effectively reversed by the added purines, except for adenine. Radioactive tracer experiments showed that the incorporation of the radioactivity from [2-14C]THP into riboflavin was negligible. The results obtained strongly suggest that THP is not an intermediate but a rigid inhibitor for riboflavin formation, and thus there is non salvage pathway of THP for the pathway of riboflavin biosynthesis in resting cells of E. ashbyii.

A kinetic study of the immediate nucleotide precursor of riboflavin in whole cells of Eremothecium ashbyii at rest.

Acid -soluble nucleotides from the mycelia were clearly separated by column chromatography on Dowex 1 X 2(HCOO-, 200 to 400 mesh). Under the experimental conditions used [2--14C] xanthine and [2--14C] guanine added were not incorporated into adenosine nucleotides but only into the guanosine nucleotides-GMP, GDP, GDP-Man, and GpA. Purines labeled at carbon 2 were effectively transferred to riboflavin but not radioactivity from [8--14C]--hypoxanthine was detected in the produced riboflavin. Comparison of the specific activity/time curves of guanosine nucleotides and riboflavin indicated that the specific activity of newly formed riboflavin coincides perfectly with that of GTP during incubation, and that the specific activity of accumulated riboflavin, at its maximum value, intersects the GTP curve. Thus, the kinetic studies with whole cells of E. ashbyii provide clear evidence that, among various nucleotides, GTP is the immediate precursor of riboflavin, and further attest that the intermediates involved in the biosynthetic pathway of the nucleotide precursor to riboflavin are in a trace amounts but have high turnover rates and, that the biosynthetic pathway has no salvage pathway for the intermediate derivatives, di- and tri-amino pyrimidines.

Possibility of diacetyl and related compounds as the 4-carbon compound necessary for the formation of riboflavin in Ashbya gossypii.

The effects of various compounds (0.5%) involved in the butanediol and the glycolytic pathways on riboflavin formation in whole cells of Ashbya gossypii at rest were examined. The addition of acetate, glycerol and diacetyl inhibited riboflavin formation, while the addition of acetoin had no effect on it, and the addition of ethanol, 2,3-butanediol, pyruvic acid and glucose accelerated it. The relation of diacetyl and acetoin to riboflavin formation during resting cell incubation in the presence of 0.5% ethanol and various concentrations of 2,3-butanediol was examined. The results quantitatively revealed a precursor-product relation between riboflavin formation and the formation of diacetyl and acetoin. The results obtained provide evidence that a high flavinogenic agent, ethanol, was converted to acetaldehyde, pyruvic acid, acetoin and diacetyl in this order, that a week flavinogenic agent, 2,3-butanediol, was transferred to diacetyl through acetoin, and that the diacetyl produced can be utilized as the 4-carbon compound for riboflavin formation in the flavinogenic mold, Ashbya gossypii. It remains obscure whether diacetyl is enzymatically involved in riboflavin formation.