A patient with right and left atrial membranes: the role of transesophageal echocardiography and magnetic resonance imaging in diagnosis

A patient who had right and left atrial membranes was examined. The diagnosis and the hemodynamic significance of both membranes were detailed by transesophageal echocardiography and were confirmed by magnetic resonance imaging. Transesophageal imaging was found to be superior to routine echocardiography in visualization of these atrial structures.     

Hemorrhagic choroidal detachment with anterior vitreoretinal adhesions.

We present three cases of large intraoperative or postoperative hemorrhagic choroidal detachment with subsequent adherence of the retina to anterior segment structures. Surgical management involved bimanual vitrectomy through anterior sclerotomy sites and dissection within the anterior segment. Successful retinal reattachment was achieved in two of these cases (18-months' follow up). In the third case, the retina remained attached for 4 months but then redetached.     

Isolating the color vision loss in primary open-angle glaucoma

We evaluated the results of Farnsworth-Munsell 100-Hue tests in age- and lens density-matched eyes of normal subjects, glaucoma suspects, and patients with primary open-angle glaucoma. With these controls in place, no significant correlation between the test results and age or between the test results and lens density was found. However, a significant difference in the total error scores on the 100-Hue test remained. This difference could not be explained by pupil size or medications taken. We concluded that color vision loss in glaucoma is in part attributable to the disease process and cannot be explained solely on the basis of changes in age and lens density.     

Effect on fetal mouse development of exposure to MR imaging and gadopentetate dimeglumine

Pregnant mice were exposed to one of five regimens at 9.5 days of gestation: no treatment (group 1), intraperitoneal injection of normal saline (group 2), intraperitoneal injection of gadopentetate dimeglumine (group 3), intraperitoneal injection of gadopentetate dimeglumine and magnetic resonance (MR) exposure (group 4), and MR exposure alone (group 5). At 18 days of gestation, the mice were sacrifice and fetuses were removed and examined for the following end points: litter size, number alive or dead, fetal weight, extremity morphology, eye and ear development, and appearance of the head. A total of 739 fetuses were analyzed: group 1 (n = 161), group 2 (n = 149), group 3 (n = 142), group 4 (n = 136), and group 5 (n = 151). The only statistically significant difference was a lower mean fetal weight in the saline-injection group compared with the control group. The results show that MR exposure with and without gadopentetate dimeglumine had no adverse effect on the end points analyzed.     

Different pattern of alkaline phosphatase, osteopontin, and osteocalcin expression in developing rat bone visualized by in situ hybridization

Alkaline phosphatase (AP), osteopontin (OP), and osteocalcin (OC) are expressed during osteoblastic differentiation. However, previous studies suggested differences in the timing and possibly the site of their expression. In this study we used in situ hybridization to follow the distribution of these osteoblastic markers during bone development. Frozen sections of neonatal rat long bones and calvariae were hybridized with 35S-labeled RNA probes complementary to the AP, OP, and OC mRNAs. Controls included sections hybridized with the sense (mRNA) probes or pretreated with RNase. Positive cells were identified in all areas of bone formation of the long bones and calvariae. Based on quantitative silver grain distribution and density, high levels of OP expression were present only in osteoblasts in close proximity to bone (one to two cell layers). OC expression, apparently at lower levels than OP, was also localized to osteoblasts in contact with bone. In contrast AP, which was expressed at lower levels than OP, was present in a large number of cells, including preosteoblasts that were many layers removed from the bone-forming surface. These findings are consistent with the asynchronous expression of phenotypically related genes and suggest that AP is an earlier differentiation marker than OP and OC during the formation of endochondral and membranous bone.     

Maternal corneal thickness during pregnancy

We measured central corneal thickness in 89 pregnant women. It was increased 16 micron (P = .01) compared to the control eyes of 18 nongravid and 17 postpartum women. There was no significant difference (P = .79) in corneal thickness between the nongravid and postpartum groups. When comparing subjects by week of gestation, there was no trend over time in corneal thickness (analysis by linear regression). Intraocular pressure was lowered during pregnancy, but it did not correlate with corneal thickness for either the pregnant or nonpregnant group.     

A double-masked three-month comparison between 0.25% betaxolol suspension and 0.5% betaxolol ophthalmic solution

In 352 patients with primary open-angle glaucoma or ocular hypertension, a multicenter double-masked, parallel-group clinical study compared the effects on intraocular pressure and ocular comfort of 0.5% betaxolol ophthalmic solution, a cardioselective beta-adrenergic blocking agent, with 0.25% betaxolol suspension. With twice-daily dosages, baseline intraocular pressure was significantly reduced (P = .0005), with no significant difference between the two groups, at Week 2 and at Months 1, 2, and 3. Further, the prevalence of ocular discomfort upon topical instillation was significantly lower for 0.25% betaxolol suspension than for 0.5% betaxolol solution (P = .0005).     

The organization of actin filaments in human polymorphonuclear leukocytes

Actin constitutes a major component of the cytoskeleton of human polymorphonuclear leukocytes (PMNs). In this study, we present a comprehensive view of the organization of actin in various PMN regions and functional states. Transmission electron microscopic observations were made on whole mount, migrating, and phagocytizing PMNs. Positive identification of actin filaments was made through S-1 myosin subfragment labeling. In all PMNs studied, actin filaments were primarily organized as a three-dimensional meshwork. The density of this meshwork was greatest within the cell cortex. At peripheral regions of nonpolarized (viz., no distinct head or tail region) and polarized PMNs, actin filaments organized into parallel bundles or overlapping arcs. These bundles or arcs were oriented either perpendicular or parallel to the cell periphery. At the base of the PMN, actin filaments converged upon dense, plaquelike condensations. This latter pattern of actin organization was also observed in some pseudopods at the cell front and in phagocytic processes engulfing bacteria. In areas of internalized bacteria, the surrounding actin appeared as a loose meshwork. Treatment of PMNs with the antiactin drug, cytochalasin B, revealed shearing of the peripheral actin meshwork, condensation of the meshwork around the nuclear region, and dissolution of the basal plaquelike condensations.