Lesion and regeneration of the anterior and posterior lens capsule and cortex in rabbits Nd:YAG laser

With a mode-locked Nd:YAG laser set at various energy levels, anterior and posterior capsular and cortical lesions were produced in the lens of rabbits. Biomicroscopic and Scheimpflug examinations showed the anterior lesion to be healing in a whitish scar that was restricted to the area of the original lesion. Histology and transmission electron microscopy (TEM) demonstrated the proliferation of epithelial cells that produced a new, continuous, basement membrane-like capsule. In the area of the lesion collagenous material, myofibroblast-like cells and macrophages were found. Laser-induced lesions in the posterior lens capsule and lens protein resulted in damage to the capsule and grey opacity of the lenticular proteins, which remained unchanged for 6 weeks. Neither inflammatory nor epithelial cells appeared within the locally damaged lens. Macrophages migrated from the vitreous into the lesion; they were observed either in intercellular clefts or within a lens fibre, almost completely taking up their cross section.

[The femoral neck pseudarthrosis following medial femoral neck fracture. An indication for the vascularized pedicled iliac crest transplant]

Revascularisation surgery was performed in six cases following medial femoral neck fracture with femoral head necrosis and non-union of the femoral neck. A corticospongiosis pelvic graft supplied by the deep circumflex iliac artery was implanted as an autologous heterotopic pedicled transplant. The operative procedure was the same in all cases, since it was possible to lift out the pelvic graft from the same side as the affected hip joint, thus making a microvascular anastomosis unnecessary. Follow-up examination after 15-27 months revealed that, in all cases, osseous consolidation of the pseudarthrosis had been achieved and that further segmental collapse of the contour of the femoral head had been prevented. The angiographic studies performed during the examination demonstrated unimpeded circulation in the pedicle of the transplants in five of the six cases, as long as 3 months after the operation. For the first time it was possible in these five cases, by means of a transplant angiograph, to demonstrate integration of the graft into the biologically weak post-traumatic transplant region.

A specific method for the direct determination of lipoprotein cholesterol in electrophoretic patterns

Lipoproteins are separated electrophoretically and cholesterol is visualised with an enzymic reagent specific for cholesterol in which the gels are incubated. Quantitation of the individual fractions is accomplished by scanning densitometry. No sample pretreatment is necessary. All major fractions are detected readily. Accuracy agrees favorably with results from the ultracentrifugation. On the average, imprecision is 3.1% for beta-, 6.9% for prebeta-, and 5.2% for alpha-lipoprotein cholesterol. Concentration and color development are linear up to 8 mmol/l cholesterol in a given lipoprotein fraction. The results of the direct enzymic procedure for beta-, prebeta- and alpha-lipoprotein cholesterol are compared to the quantitative lipoprotein electrophoresis after precipitation with phosphotungstic acid and bivalent cations.

[Disorders of retinal function in long-term therapy with retinoid etretinate]

Four patients receiving etretinate as long-term therapy were examined. The accumulated dosage was 135 g for Patient 1, about 80 g for Patients 2 and 3, and 31 g etretinate and 4.8 g etretine (Ro 10-1670; main metabolite of etretinate) for Patient 4. Clinical examinations, visual fields (Haitz, Amsler, Goldmann), and EOGs (two patients) were normal. Patient 1 (135 g) showed a decreased level of rod sensitivity at dark adaptation (Goldmann-Weekers), whereas the cone responses were regular in all cases. Furthermore, Patient 1 showed reduced scotopic ERG amplitudes. Aside from this, photopic and scotopic ERGs were normal as far as a- and b-wave amplitudes and peak latencies were concerned. The flicker fusion frequencies were found to be regular. The peak latencies of the R2-component of the early receptor potentials seemed rather short. In all four patients alterations of color sense were analyzed in the Farnsworth Munsell 100 Hue test. The color sense defect seems to originate in the blue-yellow spectrum and--at higher dosages--extends to the red-green spectrum. Examinations with the anomaloscope revealed deuteranomalous settings. Ophthalmological checks for patients receiving long-term aromatic retinoid therapy are recommended, especially with regard to dark adaptation and color sense.

Four-year follow-up of retinal status and glycosylated haemoglobin in patients with insulin-dependent diabetes mellitus

Retinal status and glycosylated hemoglobin (GHb) was followed in 32 patients with insulin-dependent diabetes mellitus (18 females; age upon entering the study 26 +/- 8 years; duration of diabetes 10 +/- 6 years; means +/- SD) during a total of 136 patient-years, i.e. during 4.3 +/- 0.6 years per patient. Annual mean GHb (given in percent of the mean normal GHb) was calculated from 7 +/- 3 determinations of GHb per patient-year. Fluorescein angiographs were performed at least once per patient-year, and retinal status was assessed by counting microaneurysms. Upon entering the study, early diabetic (background) retinopathy was present in 14 patients; at the end of the follow-up period, it was present in 20 patients. Retinal status deteriorated in 4/42 patient-years with excellent metabolic control (annual mean GHb less than or equal to 125%), in 13/70 patient-years with good control (annual mean GHb 126-150%) and in 8/24 patient-years with poor control (annual mean GHb greater than 150%). The incidence rate of retinal deterioration differed significantly between years with excellent control and years with poor control (X2 5.7, df = 1, p less than 0.05). It is concluded that excellent metabolic control within 14 +/- 6 years after onset of insulin-dependent diabetes mellitus appears to be a protective factor against the development or progression of early diabetic retinopathy.

[Classification, clinical aspects and diagnostic pathology of soft tissue tumors]

Soft tissue tumors often present a clinical problem, and their histology is heterogeneous. It is only in the last 15 years that an internationally accepted classification has been widely used to assess prognosis and determine therapy. In the present article the important clinical aspects of treatment are presented in combination with new therapeutic and diagnostic discoveries. Immunohistochemistry is now more widely used as an accepted diagnostic method than electron microscopy.

Characterization of the protein which binds insulin-like growth factor in human serum

The binding of the 125I-labelled insulin-like growth factors I and II (125I-IGF I and 125I-IGF II) to the high-molecular-mass binding protein of human serum was characterized. With diluted human serum both growth factors showed optimal specific binding at 4 degrees C and pH 5-6. When 0.1% Triton X-100 was present in the incubation buffer an increase in the affinity of the IGF-binding protein was induced, which produced an enhanced binding of IGF I and IGF II. Competition experiments with various peptide hormones revealed that the native IGF-binding protein complex binds both the IGF I and IGF II with high specificity. Analysis of binding data according to the method of Scatchard resulted in linear plots for IGF I and IGF II respectively, indicating that in human serum only a single class of non-interacting binding sites is present. At optimal binding conditions the dissociation constants were determined to be 0.28 x 10(-9) M for IGF I binding and 0.66 x 10(-9) M for IGF II. Human serum was gel-filtered on Sepharose CL-6B at neutral pH and the eluate was assayed for binding activity with both IGF I and IGF II. One peak with an apparent molecular mass of 175 kDa and a Stokes radius of 4.8 nm was determined for both growth factors. Thus, our data suggest that human serum contains one class of high-molecular-mass binding protein with comparable binding characteristics for IGF I and IGF II.

[Treatment and results in severe craniocerebral trauma]

Treatment of severe craniocerebral traumas in medium and major hospitals not provided with special neurosurgical equipment requires particularly close interdisciplinary cooperation between surgeons, neurologists and anaesthesiologists. CT facilities are an essential prerequisite for best possible patient care. Patient safety during the posttraumatic and postoperative phases is improved by measuring the intracranial pressure. Whereas corticosteroid treatment may be arguable, barbiturate treatment should presently not be a routine procedure because of its side effects and high rate of complications.

[Electroretinography in AIDS retinopathy and AIDS cytomegalovirus retinitis with ganciclovir therapy]

Electroretinographic (ERG) investigations were performed in three AIDS patients. The first had cotton wool-like spots in both eyes (AIDS "retinopathy"). The second presented with the same changes in his right eye and an acute cytomegalovirus (CMV) in his left eye. In the third patient signs of healed peripheral retinochoroiditis were found. In CMV retinitis the retinal damage demonstrated by ERG correlated well with the ophthalmoscopic findings. As the ERG improved concurrently with Ganciclovir therapy, retinal function can be monitored by means of ERG controls. In the cases of AIDS "retinopathy" with only a few cotton wool-like spots and with healed peripheral retinochoroiditis, pronounced changes in the ERG were seen regularly; these were most probably caused by ischemia of the inner retinal layers.

Nitrendipine in patients with end-stage renal disease and hypertension

Calcium antagonists reduce the calcium uptake in vascular cells. The reduction of intracellular calcium leads to vasodilatation and lowering of the blood pressure. The cardiac output is increased, for example, by nitrendipine and related agents, so that the supply of blood to essential organs is improved. Despite the blood pressure decrease, the plasma renin activity increases only slightly and the plasma aldosterone concentration not at all after administration of nitrendipine. The effects of nitrendipine were examined in a study carried out over a period of 6 months on 10 patients suffering from renal hypertension and end-stage renal disease requiring compulsory dialysis. In all patients, adequate blood pressure control was achieved with, in some cases, low doses of nitrendipine combined with other antihypertensive medication. Nitrendipine was very well tolerated, and no side effects were observed.

[Electrophysiologic and histologic retinal changes after diethylene glycol administration]

The toxic effect of diethylene glycol on the retina was studied in white New Zealand rabbits. In a three-month study diethylene glycol dissolved in water was administered orally to groups of four rabbits at dose levels of 0 (control) and 4%. The ERG revealed a dose-dependent prolongation of the b-wave and a reduction in the photopic amplitudes of the a- and b-waves. In agreement with the electrophysiological findings the histologic study of the retina showed birefringent crystals predominantly in the inner nuclear cell layer. Oxalate seemed to be a metabolite of diethylene glycol, because aggregations of calcium oxalate crystals were deposited in the kidneys and livers of the animals.

[Osteocalcin and bone histology in osteoporosis]

The decoupling of bone formation and bone resorption causes an insidious bone loss that is responsible for the negative skeletal balance in the frequent form of low turnover osteoporosis. The reduction of bone formation can hardly be verified by clinical methods. Osteocalcin, a non-collagenous bone protein, has proved to be a useful new indicator of bone formation. To establish its predictable value, plasma levels of osteocalcin were compared to conventional serological data of bone turnover and to histomorphometric parameters of iliac crest trabecular bone. In cases of osteoporosis with normal bone turnover activity (as confirmed by histomorphometry) no differences were observed in any of our laboratory data including osteocalcin. However, there was a significant lower mean serum level of osteocalcin in a group of patients with histomorphometrically proven low turnover osteoporosis in comparison to those with normal bone turnover. Serum levels of osteocalcin below 2.0 ng/ml seem to indicate a low turnover in the individual case of osteoporosis while this is unlikely when serum levels above 6.0 ng/ml are measured (according to our RIA).

Experimental carotenoid retinopathy. II. Functional and morphological alterations of the rabbit retina after acute canthaxanthin application with small unilamellar phospholipid liposomes

Eight "chinchilla bastard" pigmented rabbits were treated intravenously with sonicated phospholipid liposomes (SUV) consisting predominantly of egg yolk phosphatidylcholine (PC). Four rabbits were treated with canthaxanthin incorporated into PC liposomes in a single injection and fractionated over a period of 19 days. The total amount of PC used was a single dose of 260 mg administered as a 50-ml suspension and 13.7 mg/fraction given as a 5-ml suspension. The total amount of canthaxanthin used was a single 40 mg as a 50-ml suspension and 2.1 mg/fraction as 5-ml suspension. Electroretinography showed that canthaxanthin produced a depression of the a-waves and prolongation of the scotopic a- and b-wave peak latencies. A single high-dose injection of PC and PC plus canthaxanthin resulted in a transitory reduction in ERG amplitudes. A single injection of PC and canthaxanthin also produced hypernormal a-waves within the recovery time. Electron microscopy demonstrated that in contrast to the controls (PC), the canthaxanthin-treated rabbits showed alterations in the RPE/photoreceptor complex, indicating that these layers are the primary site of canthaxanthin effects on the retina.

[Significance of an angiogenic factor (in omental lipid) for the vascularization of the cornea]

The existence of an angiogenic factor in the omental lipid was verified by injecting four different test materials in dosages of 50 microliters into the corneas of New Zealand rabbits. The test substances were: 1) phosphate-buffered saline solution; 2) chloroform-methanol solution; 3) phosphate-buffered saline homogenate of the chloroform-methanol extract of the lipid cake from the rabbit omentum. The experimental results show that the modes of neovascularization after injection of lipid and nonlipid materials into rabbit corneas are very similar. For angiogenesis to be stimulated, the noxious substances must be retained in the cornea for several days. One day after injection the phosphate-buffered saline solution is totally resorbed. The other test substances (2-4), are retained within the cornea for days or weeks. Test substance 1 does not induce any corneal vascularization. The injection of test substances 2-4 causes similar corneal neovascularization: the proliferation of vessels always starts from that segment of the limbus closest to the stimulation. Since the extent of vascularization after injection of chloroform-methanol solution alone is similar to that which occurs after injection of an omental lipid extract, the hypothesis of a specific angiogenic factor is not supported. Fluorescein angiography reveals a large outflow of fluid (leakage) out of the neovascularization.

The white gene as a marker in a new P-element vector for gene transfer in Drosophila

We describe new vectors suitable for P-element mediated germ line transformation of Drosophila melanogaster using passenger genes whose expression does not result in a readily detectable phenotypic change of the transformed flies. The P-element vectors contain the white gene fused to the heat shock protein 70 (hsp70) gene promoter. Expression of the white gene rescues the white phenotype of recipient flies partly or completely even without heat treatment. Transformed descendents of most founder animals (GO) fall into two classes which are distinguishable by their orange and red eye colours. The different levels of white expression are presumably due to position effects associated with different chromosomal sites of insertion. Doubling of the gene dose in orange eyed fly stocks results in an easily visible darkening of the eye colour. Consequently, the generation of homozygous transformants is easily possible by simple inbreeding due to the phenotypic distinction of homo- and heterozygous transformants. Cloning into these P-element vectors is facilitated by the presence of polylinkers with 8 and 12 unique restriction sites.

Experimental carotenoid retinopathy. I. Functional and morphological alterations of the rabbit retina after 11 months dietary carotenoid application

beta-Carotene, canthaxanthin, and beta-carotene plus canthaxanthin were administered to "chinchilla bastard" pigmented rabbits in their rabbit diet (approximately 200 ppm carotenoid per group). The effect of the carotenoids on retinal function and morphology was tested against a control group in the course of 11 months. Electroretinography showed that in contrast to the control animals, beta-carotene-treated rabbits produced increasing peak latencies of the scotopic b-waves. In the canthaxanthin-treated rabbits, a- and b-waves showed hypernormal amplitudes at low cumulative dosages (approximately 0.5-2 g) and reduced amplitudes at higher dosages (about 5 g). The peak latencies of the scotopic a- and b-waves increased remarkably. This effect was still stronger in the carotenoid combination. Histology and electron microscopy indicated that in contrast to the control animals, canthaxanthin-treated rabbits showed a reduction in retinal thickness in some samples. In particular, they exhibited alterations in the granular layers and a marked diminuation of the photoreceptor outer segments and morphological alterations of the photoreceptor inner segments with massive deposition of electron-dense material. In all animals treated with carotenoids, lipid droplets of the retinal pigment epithelium were enlarged in size and number.

Generation of oligomeric insulin receptor forms by intramolecular sulfhydryl-disulfide exchange. Involvement of masked sulfhydryl groups

Insulin receptors from rat liver membranes were labelled with a 125I-labelled photoreactive insulin analogue or by iodination using lactoperoxidase and analysed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Under nonreducing conditions different receptor forms with Mr 400,000 (alpha 2 beta 2), 360,000 (alpha 2 beta beta'), 330,000 (alpha 2 beta' beta'), 320,000 (alpha 2 beta), 280,000 (alpha 2 beta'), 240,000 (alpha 2), 210,000 (alpha beta), 165,000 (alpha beta') and 115,000 (alpha) were detected. The subunit composition of these receptor forms was determined by two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis in the absence and presence of dithioerythritol. During denaturation in sodium dodecyl sulfate in the absence of reductants, the Mr 400,000 receptor form (alpha 2 beta 2) was converted into the Mr 320,000 (alpha 2 beta) and Mr 240,000 (alpha 2) receptor form. This conversion was prevented either by N-ethylmaleimide, oxidants, or low pH. In contrast, alkylation of the receptor with N-ethylmaleimide under non-denaturing conditions did not prevent the appearance of intermediate-sized receptor forms. Furthermore, the inhibition of receptor cleavage by N-ethylmaleimide during denaturation was also observed when the amount of free sulfhydryl groups was reconstituted by the addition of an unlabelled and non-alkylated receptor sample to the alkylated and photoaffinity-labelled receptor. These results suggest, that the generation of different oligomeric receptor forms detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis is due at least in part to the cleavage of one or both beta-subunits from the insulin receptor.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental calcium oxalate retinopathy compared with cystine- and tyrosine-induced retinal damage. An ophthalmoscopical, histological, and electrophysiological study

Subcutaneously administered calcium chloride and dibutyloxalate solutions produce calcium-oxalate retinopathy in rabbits that is demonstrable opthalmoscopically and histologically, with remarkable impairment of the electroretinogram, whereas orally administered cystine seems to be inefficient. Orally administered tyrosine induces transitory pathological ERG signals in rabbits.

Experimentally induced cystine keratopathy in rabbits

L-Cystine was administered orally to albino and nonalbino rabbits in order to study cystine-induced corneal lesions. Contact and noncontact specular microscopy revealed opaque preendothelial structures similar to those found in benign cystinosis in humans. Light microscopy showed cytoplasmatic vacuoles in the basal cell layer of the corneal epithelium. Using scanning electron microscopy, increased desquamation of the corneal epithelial cells and massive deposition of proteinic material on the surface of the corneal endothelium were demonstrated.