Entomopathogenic nematode (Heterorhabditidae and Steinernematidae) spatial distribution in turfgrass.

Understanding the temporal and spatial distribution of entomopathogenic nematodes is essential for determining the role of these insect parasites in soil communities and ultimately for their use in suppression of pest insect populations. We measured the vertical and horizontal distribution of endemic populations of entomopathogenic nematodes (Steinernema carpocapsae and Heterorhabditis bacteriophora) in turfgrass. Vertical distribution was determined by taking soil cores every 3 h from 05.

Assessment of chronic gamma radiosensitivity as an in vitro assay for heterozygote identification of ataxia-telangiectasia.

Ataxia-telangiectasia (A-T) is a rare human autosomal recessive disorder characterized by, among other symptoms, catastrophic reaction to conventional radiotherapy. A-T heterozygotes are clinically asymptomatic and their fibroblasts are intermediate in radiosensitivity between homozygotes and normals. We have attempted to identify heterozygotes by assaying for cellular hypersensitivity to chronic gamma irradiation.

Treatment and prevention of basal cell carcinoma with oral isotretinoin.

Twelve patients with multiple basal cell carcinomas resulting from varying causes were treated with high-dose oral isotretinoin (mean daily dosage: 3.1 mg/kg/day) for a mean of 8 months. Of the 270 tumors monitored in these patients, only 8% underwent complete clinical and histologic regression.

Linkage studies of Best's macular dystrophy.

Genetic linkage studies are presented for nine kindreds with Best's vitelliform macular dystrophy (BVMD). This condition is an autosomal dominant macular dystrophy with reduced penetrance and highly variable expressivity. Asymptomatic carriers were identified with electro-oculography, fundus photographs and fluorescein angiography.

Treatment of ichthyosis with isotretinoin.

A multicenter study of the effectiveness of 13-cis-retinoic acid (isotretinoin) in lamellar ichthyosis and epidermolytic hyperkeratosis has been conducted. A dose of the drug which produced maximum clearing with minimum side effects was chosen; this varied among different patients, the mean dose being about 2 mg/kg/day. Almost all of the patients in both groups were clearly improved, as evaluated both by the physicians and the patients.

XY gonadal dysgenesis in three siblings.

Three tall, phenotypic female siblings with XY gonadal dysgenesis were found to have short fourth metacarpal bones (bilateral in two and unilateral in the other). Clitoromegaly was observed in the two older siblings, without hirsutism. Bilateral streak gonads were found in all three.

Prolonged remissions of cystic and conglobate acne with 13-cis-retinoic acid.

Fourteen patients with treatment-resistant cystic and conglobate acne were treated for four months with oral 13-cis-retinoic acid, a synthetic isomer of naturally occurring all-trans-retinoic acid. The average dose was 2.0 mg per kilogram per day.

Normal pressure hydrocephalus. Recognition and relationship to neurological abnormalities in Cockayne's syndrome.

Normal pressure hydrocephalus (NPH) in adults is a well-known cause of dementia. We describe NPH in children having the recessively inherited Cockayne's syndrome (CS). Cockayne's syndrome is characterized by cachectic dwarfism, neurological dysfunction, and cutaneous sunlight sensitivity.

Nevoid basal cell carcinoma syndrome: radiographic manifestations including cystlike lesions of the phalanges.

The radiographic findings in 25 patients with the nevoid basal cell carcinoma syndrome are presented. Cystlike lucencies of the phalanges, a previously unreported finding, were seen in 46% of the patients in whom hand films were obtained. Mandibular cysts, present in 42% of cases, and exuberant intracranial calcifications were also characteristic features.

Cockayne's syndrome fibroblasts have increased sensitivity to ultraviolet light but normal rates of unscheduled DNA synthesis.

Cockayne's syndrome is a form of cachectic dwarfism characterized by acute sun sensitivity and numerous other abnormalities of many organ systems. We studied fibroblasts from 9 Cockayne's syndrome patients to determine if their fibroblasts had abnormal post-ultraviolet light colony-forming ability or abnormal ultraviolet light-induced unscheduled DNA synthesis. The fibroblast strains from all the patients had markedly decreased post-ultraviolet light colony-forming ability in comparison with fibroblasts from control donors.

The Rieger syndrome.

Fourteen patients with hypodontia and the ocular features of the Rieger syndrome were examined for the presence of systemic anomalies. A periumbilical defect that consisted of failure of the periumbilical skin to involute was seen in ten of the thirteen evaluated for the defect. Three others had scars over the umbilical area and had a history of surgery for herniation.

Flicker fusion thresholds in Best macular dystrophy.

Flicker fusion threshold intensities were measured as a function of flicker frequency for patients with Best macular dystrophy having normal or near-normal Snellen visual acuity. These data were found to differ from normal in ways that may be interpreted to be an abnormal elevation of the foveal cone threshold, a loss of cone temporal resolution, or both. The results led to the conclusion that Best macular dystrophy affects the neurosensory retina even when Snellen visual acuity is normal.

Familial aniridia with preserved ocular function.

Of 76 members of a large pedigree with familial aniridia, 61% of the 38 affected patients had visual acuity of 6/9 (20/30) or better and only 5% had acuity of 6/60 (20/200) or worse. Cataracts were present in 18% of affected patients; glaucoma in 13%; and strabismus in 34%. Sixteen percent of affected patients had strabismic amblyopia.

Treatment of lamellar ichthyosis and other keratinising dermatoses with an oral synthetic retinoid.

Thirteen patients with keratinising dermatoses were treated for 2-17 weeks with oral 13-cis retinoic acid. There was near complete clearing of the skin lesions beginning within 2 weeks of starting treatment in all five patients with lamellar ichthyosis (including two cases of non-bullous congenital ichthyosiform erythroderma), in two of the three patients with Darier's disease, and in one patient with pityriasis rubra pilaris. The patients with psoriasis and naevus comedonicus did not improve.