Treatment of age-related macular degeneration by laser photocoagulation. Visual results 2-8 weeks and 2-4 years after initial laser treatment

Laser treatment with blue-green argon, green argon and/or krypton red was performed on 578 eyes in 443 patients with neovascular age-related macular degeneration (AMD). The visual acuity was examined in all eyes 2 to 8 weeks after initial treatment and in 204 eyes in 167 patients 2 to 4 years after initial treatment. The short term results were as follow: 91/578 eyes (16%) had improved (greater than or equal to 2 lines on Snellen's charge or equivalent steps), 445/578 eyes (77%) remained unchanged and 42/578 eyes (7%) had deteriorated visual acuity (greater than or equal to 2 lines on Snellen's chart or equivalent steps). The reduction in visual acuity, may in about half of the 42 eyes be caused by too intensive laser application in the beginning of this study in 1983 and 1984 where treatment was applied with blue-green argon, which has now been abandoned. In the group with an observation time of 2 to 4 years, 42/204 eyes (21%) had improved, 119/204 eyes (58%) remained unchanged and 43/204 eyes (21%) had a deteriorated visual acuity. In the 204 eyes the subretinal neovascular lesion(s) were located extrafoveally in 52 eyes, juxtafoveally in 114 eyes and subfoveally in 38 eyes. It is to be pointed out, that even patients with a pre-laser visual acuity of 6/60 or worse obtained an improvement of visual acuity in 12/27 eyes. About 40% of the eyes needed re-treatment from 1 to 8 times. It is unknown whether the obtained results are to be considered marginal or more substantial.(ABSTRACT TRUNCATED AT 250 WORDS)     

Decrease of glucose in the human visual cortex during photic stimulation.

Localized proton NMR spectroscopy was used to study cerebral metabolism in the visual cortex of healthy adults during rest and photic stimulation. Basal lactate levels showed considerable interindividual differences ranging from below detectability (less than 0.3 mM) to about 1 mM without consistent alteration during photic stimulation. Local brain glucose levels were significantly reduced (approximately 50%) during the entire period of photic stimulation and recovered to resting levels (approximately 0.8 mM) within 10 min after the end of stimulation. This decrease reflects the establishment of a new equilibrium due to enhanced delivery (blood flow) and enhanced consumption. The absence of lactate accumulation supports the hypothesis of a rapid efflux of lactate from brain tissue under activated conditions.     

Anal sphincter size measured by endosonography in healthy volunteers. Effect of age, sex, and parity.

The anal sphincter muscles consist of the circular internal and external sphincters together with the sling-shaped associated puborectalis muscle. Ten men, 10 women with no vaginal deliveries, and 10 women with one or more vaginal deliveries were studied with anal endosonography using a 7 MHz multiplanar endoprobe. The thickness of the internal sphincter and the thickness, length, and cross-sectional area of the external sphincter were measured and related to age, sex, and parity. Reproducibility was assessed by similar measurements on different days in 10 volunteers. Anal sphincter size was the same in men and women and was not affected by the number of child births. Internal sphincter muscle thickness increased with age. Anal manometry and electromyography with an anal sponge were performed in all volunteers but the results did not correlate to any of the anal sphincter dimensions. Our conclusion is that although there are some limitations, endosonography can be used to determine the size of the anal sphincter muscles.     

Respiratory symptoms and lung function following exposure in workers exposed to soft paper tissue dust

Summary The objective of this study was to investigate if the dust in a mill producing soft paper tissue caused respiratory symptoms or impaired respiratory function. Using a questionnaire and spirometry, 355 persons were examined. They were divided into three groups according to present exposure to dust; low (< 1 mg/m³), moderate (1–5 mg/m³) and heavy (> 5 mg/m³). There was a dose-dependent increase of symptoms from the upper respiratory tract. However, coughing and coughing with phlegm were not found to be more common among persons with heavy exposure compared to those with low exposure to the dust. There was no difference in FEV, or FVC during a work shift. Persons with long-term (> 10 years) and heavy exposure to dust seemed to have impaired respiratory function compared to those with low and/or short-term exposure to the dust.     

Angiotensin-II contracts isolated human posterior ciliary arteries

The effect of angiotensin-II (A-II) was studied on ring segments of the terminal extraocular branches of the posterior ciliary artery isolated from human enucleated eyes. It induced a potent concentration-dependent contraction on top of the spontaneous myogenic tone of all arteries studied from five patients with the concentration required to give half-maximal response equal to 51 nM. The spontaneous tone and maximal increase in vessel wall tension induced by A-II was equal to 51% of Emax. The relative response and sensitivity to A-II was unchanged in three endothelial denuded vessels, but the spontaneous tone increased. The arteries became completely insensitive to A-II after one exposure. These results show an immediate direct contractile effect of A-II on human posterior ciliary arteries, but the development of pronounced tachyphylaxis indicates that A-II is probably not an important factor in reducing blood flow to the optic nerve head.     

Molecular identification of a small supernumerary marker chromosome by in situ hybridization: diagnosis of an isochromosome 18p with probe L1.84

A dysmorphic child was found by cytogenetic analysis to have an extra small marker chromosome. The marker chromosome was shown to possess a chromosome 18 centromere by in situ hybridization, and probably represents an isochromosome 18p. Centromere specific probes should be of value in identifying extra small marker chromosomes, and thereby provide better understanding of the clinical significance of these.     

Chronic Administration of Glucocorticoids Directly Upregulates Prepro-Neuropeptide Y and Y1-Receptor mRNA Levels in the Arcuate Nucleus of the Rat

The complete sequence of the cDNA encoding the neuropeptide Y (NPY) Y₁-receptor has recently been deduced from a rat brain library, and the presence of messenger ribonucleic acid (mRNA) encoding Y₁-receptor protein has been demonstrated within the brain. Using quantitative in situ hybridization histochemistry, the content and distribution of Y₁receptor and preproNPY mRNAs have been investigated in the hypothalamic arcuate nucleus of adrenalectomized rats receiving glucocorticoid replacement therapy for 12 days by means of either high doses of dexamethasone in their drinking water or by subcutaneous corticosterone pellets. Basal metabolic parameters such as weight gain or loss, blood glucose and plasma insulin were monitored: Dexamethasone treatment induced weight loss and a state of hyperinsulinemia with normoglycemia, while corticosterone treated animals displayed metabolic parameters identical to sham ADX animals. Within the arcuate nucleus of glucocorticoid treated animals, levels of Y₁receptor and preproNPY mRNAs were increased. In contrast, adrenalectomy itself had no effect upon Y₁-receptor mRNA levels or preproNPY mRNA levels in the arcuate nucleus. These studies demonstrate that glucocorticoids exert a stimulatory action on levels of Y₁-receptor mRNA and preproNPY mRNA levels in the hypothalamic arcuate nucleus. This is the first evidence to suggest that the expression of a neuropeptide-receptor gene in the central nervous system may be directly sensitive to peripheral hormonal signals.     

Precise and accurate measurement of proton T1 in human brain in vivo: Validation and preliminary clinical application

Precise and accurate inversion-recovery (PAIR) magnetic resonance (MR) measurements of T1 were obtained in eight brain regions and cerebrospinal fluid of 26 healthy volunteers. Accuracy of the technique was assessed by measuring T1 in small fluid volumes with the PAIR technique and with two independent spectroscopic techniques. The mean difference between T1 measured with PAIR and with the two spectroscopic techniques was 3.1% ± 1.3. The precision (reproducibility) of measurements with the PAIR technique was excellent. The coefficient of variation (CV) across 16 measurements in a head phantom was 2.0%, compared with a CV of 2.7% across 45 separate measurements in a single subject. The within-subject CV was 1.8% ± 0.6 in white matter and 1.4% ± 1.0 in basal ganglia. The between-subject CV in 26 healthy volunteers was 3.6% ± 0.6 in white matter and 4.1% ± 1.9 in basal ganglia. Comparison between a patient with an active recurrent brain tumor and an agematched patient with an inactive brain tumor showed that T1 was significantly elevated throughout the brain of the active-tumor patient, especially in white matter tracts, even though no tumor or edema was detected in the white matter on standard MR images. Comparisons between five brain tumor patients and four healthy volunteers of similar age showed that T1 was significantly and substantially elevated throughout the white matter tracts and in the caudate nucleus, putamen, and thalamus. These results are consistent with the hypothesis that white matter tracts are selectively vulnerable to edema and that T1 increases in white matter are a sensitive indicator of patient status or tumor aggressiveness.