Metal resistance and plasmid DNA in Thiobacillus ferrooxidans.

The minimal inhibitory concentrations of copper and nickel were determined for each of fifteen isolates of T. ferrooxidans native to a Cu/Ni tailings environment. Ten isolates were inhibited by 160 mM Cu2+ or less, and ten were inhibited by 160 mM Ni2+ or less. The isolates were screened for plasmid DNA using an alkaline lysis method and CCC plasmid forms were confirmed using the Hintermann technique. Two isolates were found to be devoid of plasmid DNA, and only one isolate contained more than two plasmids. Variability existed in plasmid size, although the majority were larger than the standard pBR322 (4.3 kbp). One plasmid was selected for further analysis using restriction endonucleases. EcoRI, HindIII and KpnI all cleaved the plasmid in two locations, and PstI cleaved the plasmid in six locations. PstI-digested fragments of the plasmid were ligated into pBR322, and the recombinant plasmids were transformed into Escherichia coli ATCC 8739. Four genetically-different transformants resulted, and each was grown in media containing 2.0 mM Cu2+ and compared to the growth of a control under similar conditions. There was no conferred copper resistance in E. coli, although one recombinant plasmid appeared to decrease the tolerance for E. coli ATCC 8739 to Cu2+.

Comparison of the oculokinetic perimetry glaucoma screener with two types of visual field analyser.

We compared the accuracy and testing time of a new 26-point central visual field glaucoma screening device, the oculokinetic perimetry (OKP) screener, with the results obtained with the Friedmann field analyser standard program (phase 1) and the Humphrey field analyser 40-point screening program (phase 2). Seventy-three eyes of 73 subjects were tested in phase 1, and 142 eyes of 75 subjects in phase 2. The study population comprised patients with eyes that were ocularly normal and patients with eyes showing early cataract, posterior vitreous detachment, established chronic open-angle glaucoma or ocular hypertension. The OKP glaucoma screener demonstrated a sector concordance rate of 95% in phase 1 and 93% in phase 2. The OKP screener was three to four times more rapid in execution than the standard device. We feel that the OKP glaucoma screener is ideally suited for use by physicians in a family practice setting.

Management and diagnosis of glaucoma for the family physician.

Glaucoma, from whatever cause, is a relatively common affliction, characterized by a progressive unremitting course. The optic neuropathy frequently is asymptomatic. The goal of treatment is to halt progression because a cure is unavailable for many patients. A significant number of patients will have a visual deficit that will qualify them for blind registration. Early detection is therefore important. The family physician is in a unique position to oversee the processes of detection and management.

Vogt-Koyanagi-Harada syndrome variant.

We describe a 39-year-old white woman with severe visual loss, nyctalopia, vitritis and widespread loss of retinal pigment epithelium associated with vitiligo and alopecia, which may represent a variant of the Vogt-Koyanagi-Harada syndrome.

The glaucoma suspect: differentiation of the future glaucomatous eye from the non-glaucomatous suspect eye. 1. Ultrasonic measurements and eye-wall stress.

We examined the eyes of a group of patients entered into and still continuing in a glaucoma suspect study. Over time, some remained unchanged while others developed chronic open-angle glaucoma (COAG). By comparing the data obtained by ultrasonic measurement of the axial length (A) and central corneal thickness (CCT), along with measurement of intra-ocular pressure (IOP) from these patients and normal control subjects, we found no differences. However, by combining these factors in a calculation of eye-wall stress we found a significant difference between the glaucoma suspect and the future glaucomatous eye.

The glaucoma suspect: differentiation of the future glaucoma eye from the non-glaucomatous suspect eye. 2. Visual field decay.

Visual-field areas to a I2e stimulus were measured planimetrically using an X-Y digitizer and a computer program. Sampling of normal subjects and patients suspected of having glaucoma was done at two points in time. Calculations of eye-wall stress were done using ultrasonic data and intra-ocular pressure (IOP) measurements from patient records. For those suspected of having glaucoma who developed chronic open-angle glaucoma (COAG), the time of transition was the second point in time. The visual field area was regressed against patient age at the two points in time. No difference in the regression slopes was found for the normal subjects and unchanged patients. The patients who did develop glaucoma were significantly different. The mean annual rate of visual-field change (rate of decay) was calculated and found to be 28.5 mm2/year for the normals, 153.5 mm2/year for the suspects, and 376.4 mm2/year for those patients who developed glaucoma. The rate of visual-field decay only correlated with patient age (P = 0.03) and eye-wall stress (P less than 0.01) in the patients who developed glaucoma.

Plasma lipid patterns in patients with suspected glaucoma.

We carried out analysis of plasma lipid and lipoprotein levels in 183 patients (92 women and 91 men) referred because of suspected glaucoma. We found an excess of hypertriglyceridemia among the women. Type IV lipoproteinemia was the most common lipoprotein abnormality. Lipid analysis was unhelpful in determining whether glaucoma was present or what type of glaucoma was present. The prevalence of cardiovascular disease was similar among patients with and without a lipoprotein abnormality.

Area of visual field and colour discrimination combined as a predictor of chronic open-angle glaucoma.

Area of visual field and colour discrimination were assessed in 167 eyes with ocular hypertension (from 100 women and 67 men with a mean age of 59.8 +/- 11.3 years). The patients were then followed for 3 years. During the follow-up period chronic open-angle glaucoma was diagnosed in 8 (8%) of the 100 eyes with a normal visual field and normal colour discrimination, 7 (14%) of the 50 eyes with a subnormal visual field or subnormal colour discrimination, and 17 (100%) of the 17 eyes with both a subnormal visual field and subnormal colour discrimination, a total of 32 eyes (19%). Our results suggest that chronic open-angle glaucoma develops early in ocular hypertensive eyes in which both the visual field and colour discrimination are subnormal. Glaucoma may not develop at all in eyes with normal values.

A syndrome of brain, inner ear and retinal microangiopathy.

We report the seventh case of a self-limiting syndrome of brain, inner ear and retinal microangiopathy which affects adult women producing mild to moderate mental status and personality changes, mild pyramidal and cerebellar dysfunction, patchy and asymmetrical visual loss secondary to non-inflammatory retinal infarctions, and asymmetrical neurosensory hearing loss. There is no clinical or laboratory evidence of involvement beyond the brain, the eyes and the ears. Magnetic resonance imaging or brain biopsy in previously reported cases best outline the brain pathology: multiple microinfarcts. All cases have been treated with steroids or cyclophosphamide. The etiology is unknown but may be related to systemic lupus erythematosus.

Ultrastructure of an intraocular lacrimal gland choristoma.

An intraocular lacrimal gland choristoma which was at first mistaken for a medulloepithelioma (diktyoma) was studied with the electron microscope. The tumour did not contain cells with neuronal and glial differentiation as expected in a medulloepithelioma but it did contain acini, ducts and dilated ducts or cysts. The tumour, in fact, bore much resemblance to the lacrimal gland, in that it contained electron-dense serous granules, and at times, a myoepithelial cell was detected at the base of an acinus. The ductal and cystic elements were lined by a single layer of cells or by stratified or pseudostratified epithelium. An interesting, unexpected feature was the occurrence of a myoid band (composed of thin filaments with focal densities along their course) under the cell membrane of the epithelial cells adjacent to the lumen of the ducts and cysts.

Lacrimal gland choristoma of the ciliary body.

A 22-month-old girl was found to have a pigmented mass of the ciliary body of the right eye. Five months later the globe was enucleated because of enlargement of the tumor and the appearance of brown pigment on the adjacent epibulbar surface. Histopathologic examination disclosed a lacrimal gland choristoma of the ciliary body with involvement of the limbal conjunctival surface and superficial sclera. Choristomas of the lacrimal gland are rare and only eight cases have been reported previously to occur intraocularly. Most of these cases showed extrascleral involvement which suggests that the anlage for these choristomas may be entrapped intraocularly during the development of the globe. We recommend conservative management, either by observation or local resection if possible.

Autosomal dominant iridogoniodysgenesis with associated somatic anomalies: four-generation family with Rieger's syndrome.

A family extending over 4 generations showed iridogoniodysgenesis accompanied by somatic malformations inherited in an autosomal dominant fashion. Iridogoniodysgenesis was present in 10 members, of whom 5 had established glaucoma; 4 youthful members are likely to develop glaucoma. Somatic malformations were present in 5 members from the 3rd and 4th generations who did not manifest iridogoniodysgenesis. A possible polygenic basis is discussed, though the variable expression of an autosomal dominant inheritance is still the more likely explanation.

Recurrence of benign orbital neurilemmoma (schwannoma) after 22 years.

A 34-year-old woman underwent removal of a mass from the apex of her left orbit. Histologically it was shown to be a benign neurilemmoma (schwannoma), similar in structure but dissimilar in density of nuclei and stromal appearance to a tumour removed from the same orbit 22 years previously. No cutaneous stigmata of von Recklinghausen's disease were observed.

Giant melanosomes in the eye of the Dutch rabbit.

Giant melanosomes measuring up to about 5.1 micrometers in diameter were seen in the eyes of rabbits with metallic implants. Somewhat smaller giant melanosomes up to about 2.7 micrometers in diameter were seen in the normal eye of a rabbit. Such melanosomes were not found in eyes of rabbits less than a day old. Some giant Stage IV melanosomes appear to derive from giant Stage III melanosomes with an internal structure similar to that in the normal smaller melanosomes, while others appear to be derived by fusion of smaller melanosomes. There may be yet another mechanism of production of giant melanosomes involving 'vesicular' structures but about this one cannot be certain.

Prognostic indicators in ocular hypertension.

Decreased pupil size and lens opacity, rather than high intraocular pressure, have been cited as reasons for the concentric constriction of the visual field occurring in eyes with suspected glaucoma. We studied a group of eyes showing ocular hypertension and found increased concentric constriction of the visual field when compared with that of healthy control eyes. While the degree of constriction and patient age tended to predict the transition to glaucoma, we found the absence of hypermetropia to be a strong prognostic indicator.

Clearance of debris from the iris through the drainage angle of the rabbit's eye.

The fate of particulate material on entering the drainage angle of the rabbit's eye was investigated by transmission electron microscopy. The infiltrate was produced by photocoagulation of the iris. Initially it consisted of plasma, connective tissue and cellular debris, fibrin, and red blood cells. Later, free melanin granules, polymorphs, macrophages, and iris clump cells were all seen to enter the drainage system. Native meshwork cells were found to be active phagocytes and began to degrade various components of the infiltrate within 2 hours of the formation of the iris lesions. Corneal endothelial cells, the cells which cover the iris pillars, and the adventitial cells of the ciliary body were less active but were also phagocytic.