PubMed Health⌕ Search

Biomedical subjects

D K Roberts

Publications and source records attributed to D K Roberts.

At least 19 recordsLinked to original sources
PubMed1992

Ultrastructure of the microvasculature in the human endometrium throughout the normal menstrual cycle.

In the early proliferative phase endometrial capillary basal lamina is loosely formed and discontinuous. It becomes more distinct in the late proliferative phase and develops whorled extensions that include pericytes in the early secretory to midsecretory phase. Throughout the cycle both endothelial cells and pericytes possess cytoplasmic processes that extend through discontinuities in the basal lamina and make contact with each other. These contacts may be simple or complex. They become more elaborate as the cycle progresses to the midsecretory phase. Endothelial cells show progressive but heterogeneous differentiation into the midsecretory phase, with individual cell hypertrophy. In the late-secretory phase the endometrial stroma and the basal lamina are characterized by widespread degeneration, and the cell-to-cell contacts sharply decrease. However, endothelial cells remain relatively intact.

Cytoplasm↗
PubMed1992

Light-induced amaurosis associated with carotid occlusive disease.

A 74-year-old man with the isolated complaint of uniocular transient visual loss after exposure to bright light was found to have severe ipsilateral, atherosclerotic carotid occlusive disease. Signs of ocular ischemia that were present included slightly reduced visual acuity, mild afferent pupillary defect, lowered intraocular pressure, increased photostress recovery time, and reduced opthalmodynamometry values on the affected side. After a subclavian to internal carotid artery bypass procedure, the patient's symptoms resolved completely and his ocular signs returned to normal. This patient's initial symptom, referred to as light-induced amaurosis (LIA), is an unfamiliar manifestation of the ocular ischemic syndrome. We discuss the condition and summarize the literature.

Aged↗
PubMed1991

Bilateral monocular diplopia secondary to occult diabetes mellitus.

A 68-year-old man presented with transient, bilateral, vertical, monocular diplopia as an initial manifestation of diabetes mellitus. The diplopia was determined to be of lenticular origin, but was not found to be secondary to the usual refractive changes. Rather, it is presumed to be due to prismatic alterations caused by index of refraction differences within the crystalline lenses. It is not known what other factors relate to the development of this type of diplopia in the diabetic patient.

Aged↗
PubMed1991

Keratoconjunctivitis sicca.

Keratoconjunctivitis sicca (KCS) is one of the dry eye syndromes characterized by a deficiency of the aqueous layer of the tear film. The disorder may occur as an isolated entity or in association with a variety of local and systemic conditions affecting aqueous production. Often it follows a mild course but in severe cases, complications resulting in blindness may occur. In this paper, the clinical features, diagnostic strategies, and current treatment of KCS will be covered. Etiologies, including a discussion of the Sjögren syndrome, will also be presented.

Diagnosis, Differential↗
PubMed1991

Idiopathic multiple serous detachments of the retinal pigment epithelium: a report of two cases.

A relatively uncommon entity is described which is characterized by idiopathic serous detachments of the retinal pigment epithelium (RPE). In contrast to RPE detachments associated with the spectrum of age-related macular degeneration and other choroidal diseases, the visual prognosis in this entity is usually good. In some respects, idiopathic serous RPE detachments display characteristics similar to idiopathic central serous chorioretinopathy and could be a variant thereof. The differential diagnosis also includes multifocal Best's vitelliform dystrophy.

Diagnosis, Differential↗
PubMed1990

TAC use and absorption of cocaine in a pediatric emergency department.

The topical anesthetic TAC (tetracaine 0.5%, adrenaline 0.05%, cocaine 11.8%) has been reported to be effective in pain control for local procedures. However, it has the potential for cocaine toxicity by absorption through an open wound. A study was undertaken to assess the systemic absorption of cocaine and its metabolites when TAC is used as a local anesthetic. Fifty-one children, 1 to 14 years of age, were enrolled in the study. Plasma for cocaine and/or its metabolite levels was available from 46 children and obtained 20 to 40 minutes after the topical anesthetic was applied. No plasma sample had detectable parent cocaine levels; however, 26 (56.5%) had cocaine metabolite levels. Ecgonine methylester levels were detected in plasma from six children and ranged from 59 to 985 ng/mL. Benzoylecgonine levels were detected in none of 19 specimens not preserved with sodium fluoride, and in 23 of 27 specimens to which sodium fluoride had been added. Benzoylecgonine levels ranged from 40 to more than 600 ng/mL. No clinical sign of cocaine toxicity was observed in any child.

Administration, Topical↗
PubMed1989

Experience with the Groshong long-term central venous catheter.

A study of the Groshong catheter in a gynecologic oncology population is presented, describing the catheter's ease of insertion, and patient acceptance and compliance in catheter care. From December 1985 through November 1987, 72 Groshong catheters were inserted in 67 patients. The Groshong differs from conventional Hickman-type catheters in design and maintenance. Thirty-two of 72 catheters (44%) were inserted under local anesthesia. The remaining catheters were inserted under general anesthesia at the time of major gynecologic procedures. None of the cases required fluoroscopy. The insertion technique is less traumatic than conventional approaches because of a stainless steel tunneling device. The median duration of use was 191 days. There were no cases of pneumothorax or catheter occlusion. Catheter removal was required in four cases with skin infection unresponsive to local therapy and in two cases with bacteremia. One patient developed thrombosis of the right subclavian vein but was treated without catheter removal. One patient with a skin infection at the exit site accidentally dislodged her catheter. The overall complication rate was 11% (8 of 72 cases).

Catheterization, Central Venous↗
PubMed1989

Changes in nuclear and nucleolar areas of endometrial glandular cells throughout the menstrual cycle.

Reproducible measures of the ultrastructural changes occurring throughout the normal human menstrual cycle are useful for defining and differentiating between normal and pathological states. Glandular endometrial functionalis epithelium obtained from five menstrual cycle subphases (early and late proliferative; and early, middle and late secretory) has been quantitated and compared for changes in nuclear and nucleolar size. These analyses indicate that (a) nuclear area significantly increases in the late secretory subphase, perhaps a requirement of endometrial regeneration; (b) nucleolar area peaks during the early secretory subphase, a necessary prelude for the later increased secretory activity; and (c) nucleolar area declines in the middle and late secretory subphases, probably due to falling hormone blood levels late in the cycle. In the proliferative phase, the majority of cells containing large nuclei and nucleoli have a relatively undeveloped cytoplasm, while the cytoplasm of those in the secretory phase contains glycogen. These cells were termed Stage 1 and 2 cells, respectively. The late secretory subphase contains some degenerating mature epithelial cells with large nuclei and small nucleoli as well as differentiated and regenerating cells with larger nucleoli. These measures establish a baseline of the normal changes in nuclear and nucleolar size as they occur throughout the normal human menstrual cycle.

Biopsy↗
PubMed1988

Ultrastructural evidence of stromal/epithelial interactions in the human endometrial cycle.

We found ultrastructural evidence of interactions between glandular epithelium and superficial stromal cells of the human endometrium during phases of the menstrual cycle. Four significant changes were observed in the transition from early proliferative (days 5 to 9) to early secretory (days 15 to 19) phases. These changes included: (1) an increase in the number and size of lamina densa disruptions, (2) an increase in the number and size of gap junctions, (3) an increase in the number and complexity of epithelial cell projections that extended through the lamina densa, and (4) an increase in close contacts between stromal and epithelial cells. The complex epithelial cell projections that extended through the lamina densa were in close proximity to stromal cells. These interactions were seen primarily in the early secretory phase. After that time (days 20 to 28) the interactions were less frequent. These morphologic results reveal complex physical interactions between epithelial and stromal cells of the adult endometrium. The interactions reach maximal development during the preimplantation phase of the endometrial cycle.

Adult↗
PubMed1988

Interaction of epithelial and stromal cells in vaginal adenosis.

Two types of direct contact between epithelial and stromal cells in patients with vaginal adenosis are documented in electron micrographs. In the first type, epithelial cells send cytoplasmic extensions through the basal lamina to achieve, at times, complete fusion with fibroblasts in the stromal compartment. In the second type, mast cells act as intermediaries between the epithelial and stromal compartments.

Epithelium↗
PubMed1988

Iris microhemangiomas.

Iris microhemangiomas (IM) are benign proliferations of small, twisted blood vessels along the pupillary margin. They are usually bilateral and appear to be developmental in nature. IMs most commonly occur in patients with myotonic dystrophy and adult-onset diabetes mellitus, but have also been associated with respiratory disease, congential heart disease, and central retinal vein occlusion. Additionally, they may be found in individuals without obvious ocular or systemic abnormality. The etiology remains obscure. In this report, illustrative cases are followed by a brief discussion outlining typical clinical manifestations, etiological considerations, and possible implications.

Aged↗