Corneal neovascularization treated with argon laser

The argon laser set at 50 mum, 100-150 mW, o-2 s occluded corneal blood vessels in pigmented Dutch rabbits provided the corneal responsible for inducing vascularization was inactive. After arterial treatment with the argon laser retrograde flow in untreated veins was demonstrated by fluorescein angiography. Therefore all corneal new vessels should be treated, not just arteries. Minimal iris damage complicated the laser therapy, but this was not thought necessarily to contraindicate the use of the argon laser to treat corneal blood vessels in man. The iris damage was associated with outpouring of aqueous from the ciliary processes, and it took up to a week for the blood-aqueous barrier to return to its normal state.     

Bulling among yearling feedlot steers

The effect of ingestion of 250 ml X-ray contrast medium on resting gastrooesophageal sphincter pressure was studied in 10 normal human subjects. Twenty minutes after initiated intake of the contrast medium, a significant fall in sphincter pressure was recorded. In the light of studies on the neurogenic and hormonal regulation of the sphincter pressure it is attempted to account for this effect, and it is concluded that it must be a manifestation of a reflectory relaxation of the sphincter region. From a clinical point of view the consequence must be a demand for standardized conditions with regard to composition and pH of the contrast medium, time schedule and degree of abdominal compression in those cases in which radiological evaluation of the resistance against reflux is called for.     

Gangrenous pyoderma and IgA-paraproteinemia

A gammaAchi--paraproteinemia was found in a 73 year-old female patient with pyoderma gangraenosum. Since the paraporteins hitherto observed in pyoderma gangraenosum predominantly belong to the IgA class, a relationship may exist between pyoderma gangraenosum and this type of paraproteinemia.     

The renal medulla and mechanisms of hypertension in the spontaneously hypertensive rat

A significant number of offspring from brother-sister matings of NIH-Okamoto-Aoki spontaneously hypertensive rats (SHRs) were found to be normotensive at 20 weeks of age. Over 20% of the animals that were hypertensive at this age had mild-to-moderate unilateral hydronephrosis at the time of sacrifice. In over 90% of the rats that did not develop hypertension spontaneously, ligation of one ureter raised blood pressure above 150 mm Hg within 2 weeks. In those rats made hypertensive by obstructing one ureter and in those that developed hypertension with accompanying naturally occurring hydronephrosis, subcutaneous implants of fragmented renal medulla from unrelated normal rats decreased blood pressure to normotensive levels. In contrast, medullary implants had no significant effect in rats developing hypertension spontaneously without hydronephrosis. Renal inner medullary plasma flow was low in the obstructed kidneys of hydronephrotic hypertensive SHRs but was elevated in the kidneys of nonhydronephrotic hypertensive SHRs. The hypertension in hydronephrotic SHRs appears to be related to an impairment of the antihypertensive function of the renal medulla. Such an impairment of medullary antihypertensive function does not appear to play a significant role in the hypertension in SHRs without hydronephrosis.     

Cytogenetic variants in holoprosencephaly. Report of a case and review of the literature

A new infant with classical features of holoprosencephaly and multiple extracranial malformations was found to have abnormal karyotype: 47, XX, + 13. Although trisomy D has been reported in a few cases, our case is the first, to our knowledge, in which positive identification of trisomy 13 was made by banding technique in cebocephaly.     

Nicotinic acetylcholine receptor from rat brain. Solubilization, partial purification, and characterization

Nicotinic acetylcholine receptor protein (nAChR) has been solubilized from rat cerebral cortices by extracting a crude membrane fraction with the nonionic detergent Triton X-100 (polyoxyethylene-p-t-octylphenol). The solubilized nAChR was partially purified by affinity chromatography (Naja naja siamensis alpha-toxin affinity arm, linked to Sepharose 4B) and characterized by binding of 125I-labeled alpha-bungarotoxin. The reaction of labeled toxin and nAChR appears to be second order with a rate constant (k1) equal to 0.38 X 10(5) M-1 S-1 at 20 degrees. The toxin-nAChR complex dissociates with a dissociation rate constant (k-1) of 1.23 X 10(-5) S-1 at 20 degrees (t 1/2 = 15.6 h). The kinetically determined dissociation constant (Kd) for the complex is 3.24 X 10(-10) M. A variety of cholinergic ligands were studied for their ability to inhibit binding of labeled toxin. The results indicate that the brain receptor is indeed nicotinic. The s20, w and v of the toxin-nAChR complex in 0.1% Triton were determined by velocity sedimentation in D2O and H2O sucrose gradients. The values are 12.9 S and 0.80 cm3 g-1. The Stokes radius of the complex determined by gel filtration equals 7.5 nm. The Mr of the complex calculated from the hydrodynamic parameters, and corrected for bound detergent, equals 357,000.     

Binding of radioactively labeled carboxyatractyloside, atractyloside and bongkrekic acid to the ADP translocator of potato mitochondria

1. The inhibition of the ADP-stimulated respiration of potato mitochondria by carboxyatractyloside is relieved by high concentration of ADP or by the uncoupler carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP). Atractyloside is a much less potent inhibitor than carboxyatractyloside. The inhibition of the ADP-stimulated respiration required about 60-times more atractyloside than carboxyatractyloside. 2. [35S]carboxyatractyloside and [3H]bongkrekic acid bind to potato mitochondria with high affinity (Kd = 10 to 20 nM, n=0.6-0.7 nmol per mg protein). Added ADP competes with carboxyatractyloside for binding; on the contrary ADP increases the amount of bound bongkrekic acid. [3H]atractyloside binds to potato mitochondria with a much lower affinity (Kd=0.45 muM) than carboxyatractyloside or bongkrekic acid. 3. Bound [3H]atractyloside is displaced by ADP, carboxyatractyloside and bongkrekic acid. The displacement of bound [35S]carboxyatractyloside by bongkrekic acid and of bound [3H]bongkrekic acid by carboxyatractyloside is markedly increased by ADP. 4. Bongkrekic acid competes with [35S]carboxyatractyloside for binding. Addition of a small concentration of ADP considerably enhances the inhibitory effect of bongkrekic acid on [35S]carboxyatractyloside binding. 5. The adenine nucleotide content of potato mitochondria is of the order of 1 nmol per mg protein. ADP transport in potato mitochondria is inhibited by atractyloside 30- to 40-times less efficiently than by carboxyatractyloside.