Search PubMed⌕ Search

Biomedical subjects

B Miller

Publications and source records attributed to B Miller.

At least 55 records · Page 3Linked to original sources
PubMed1998

Lack of effect of prophylactic gentamicin treatment on intraocular and extraocular fluid cultures after pars plana vitrectomy.

BACKGROUND AND OBJECTIVE: To analyze the effect of preoperative prophylatic 0.3% gentamicin sulfate eyedrops on intraocular and extraocular fluid cultures after pars plana vitrectomy. PATIENTS AND METHODS: Forty consecutive patients undergoing pars plana vitrectomy were randomly assigned to receive either 0.3% gentamicin eyedrops or placebo preoperatively. Fluids from the vitreous cavity and from the conjunctival sac were collected for bacteriologic studies. RESULTS: Positive cultures from extraocular fluids were obtained in 30.4% of the gentamicin group and 35.3% of the placebo group (P = .75). Furthermore, 1 (3%) of 40 cultures of intraocular fluid and 13 (33%) of 40 cultures of extraocular fluid were positive. Culture growth positivity was not influenced by the patients' age, by diabetes, or by the duration of the operation. CONCLUSIONS: Prophylactic gentamicin treatment by the method applied in this study is not effective on reducing growth positivity. Contaminated extraocular fluid may play an important role in the pathogenesis of bacterial endophthalmitis following pars plana vitrectomy.

Administration, Topical↗
PubMed1998

Mortality of industrial workers exposed to acrylonitrile.

OBJECTIVES: This study was designed to evaluate the relationship between occupational exposure to acrylonitrile and cancer mortality. MATERIALS AND METHODS: Workers (18079 white men, 4293 white women, 2191 nonwhite men, and 897 nonwhite women) employed in acrylonitrile production or use in the 1950s through 1983 were followed through 1989 for vital status and cause of death. Exposure-response relationships were evaluated from quantitative estimates of historical exposures. Tobacco use was determined for a sample of workers to assess potential confounding. Mortality rates between the exposed and unexposed workers in the cohort were compared using the Poisson regression. RESULTS: Analyses by cumulative, average, peak, intensity, duration, and lagged exposure revealed no elevated risk of cancers of the stomach, brain, breast, prostate or lymphatic and hematopoietic systems. Mortality from lung cancer was elevated for the highest quintile of cumulative exposure. When the decile categories were used, the relative risk did not continue to increase at higher levels. Adjustment for cigarette use reduced the risk for lung cancer only slightly. Separate analyses for wage and salaried workers, long-term and short-term workers, fiber and nonfiber plants, and individual plants revealed no clear exposure-response patterns. CONCLUSIONS: The results indicate that exposure to acrylonitrile at the levels studied is not associated with an increased relative risk for most cancers of a priori interest. The excess of lung cancer in the highest quintile of cumulative exposure may indicate carcinogenic activity at the highest levels of exposure, but analyses of exposure-response do not provide strong or consistent evidence for a causal association.

Acrylonitrile↗
PubMed1998

Nd:YAG laser treatment for premacular hemorrhage.

The authors describe two cases of premacular hemorrhage secondary to retinal macroaneurysm, with significant loss of vision. A few low-energy bursts of ND:YAG laser were applied to perforate the anterior surface of the hemorrhage, subsequently draining the blood into the vitreous cavity. The blood gradually cleared from the vitreous, with restoration of good vision. Nd:YAG laser seems to be a safe and efficient method for treating premacular hemorrhage and should be considered as a therapeutic option.

Aged↗
PubMed1997

[Traumatic hyphema].

Traumatic hyphema usually occurs in young men at the rate of 17-20/1000,000. Major complications include secondary hemorrhage, glaucoma, corneal staining and disturbances in visual acuity. Final visual acuity is predominantly the outcome of all the ocular injuries occurring during the trauma, mainly to the posterior segment of the eye. We describe all cases of traumatic hyphema treated in our department over a period of 3.5 years. Antifibrinolytic treatment is recommended in the literature in traumatic hyphema to prevent secondary hemorrhage. Our findings differ from those in the literature in that they show a lower prevalence of more severe hemorrhages and of secondary hemorrhage. In light of these differences, and with regard to possible side effects of such treatment, we suggest that antifibrinolytic treatment not be used in our population. We recommend that treatment for traumatic hyphema should include restricted activity, local corti-costeroidal preparations, frequent follow-up visits and vigorous diagnostic work-up in order to find any additional eye damage. We strongly recommend the use of preventive measures (eye-shields) in high risk activities such as sports, house-hold work and military training.

Adult↗
PubMed1997

[Occupational accidents and eye injuries treated at the Rambam Medical Center].

To determine the prevalence of occupation-related eye injuries, we analyzed the records of 24,632 patients treated at our emergency surgical department over a 3-year period. Occupational accidents accounted for 17.6% of such cases. A third of them (1374 patients) were referred to the ophthalmic emergency room for further examination. In 89% (1223) of these, at least 1 pathological ocular finding was detected, and 8.3% (114) of them were hospitalized. Penetrating eye injuries were found in 5.2% (72). The commonest eye injury was corneal foreign body found in 42.8%.

Accidents, Occupational↗
PubMed1997

Comparative evaluation of the in vitro micronucleus test and the in vitro chromosome aberration test: industrial experience.

Because of its rapidness, simplicity and potential for automation, the measurement of micronucleated cells in vivo is not only equivalent to the analysis of chromosome aberrations, but often even preferred within routine genotoxicity testing. In order to evaluate the correlation between the in vitro micronucleus assay (MNT) and the in vitro chromosome aberration test (CA), we collected data from four pharmaceutical companies obtained either in Chinese hamster cell lines (CHO-K5, CHO-K1, V79) or in human peripheral blood lymphocytes. Among the 57 compounds included in this comparison, 45 compounds gave rise to concordant results in both assays (26 compounds negative in both assays; 19 compounds positive in both assays). The high percentage of concordance, i.e. about 79% is very promising and can be even increased to about 88% by omitting the 3 aneugenic compounds and 2 compounds inducing endoreduplicated chromosomes which were found positive only in the in vitro MNT. The results are remarkable in particular considering that most of the compounds evaluated are 'standard' pharmaceutical compounds and thus are at most weak inducers of chromosome damage. Our comparison strongly supports that the in vitro micronucleus test is a suitable alternative to the in vitro chromosome aberration assay. Moreover, the MNT has the potential of not only detecting clastogens but additionally aneuploidy inducing chemicals.

Animals↗
PubMed1997

The monomeric G-proteins Rac1 and/or Cdc42 are required for the inhibition of voltage-dependent calcium current by bradykinin.

Although regulation of voltage-dependent calcium current (ICa,V) by neurotransmitters is a ubiquitous mechanism among nerve cells, the signaling pathways involved are not well understood. We have determined previously that in a neuroblastoma-glioma hybrid cell line (NG108-15), the heterotrimeric G-protein G13 mediates the inhibition of ICa,V produced by bradykinin (BK) via an unknown mechanism. Various reports indicate that G13 can couple to RhoA, Rac1, and Cdc42, which are closely related members of the Rho family of monomeric G-proteins. We have investigated their role as signaling intermediates in the pathway used by BK to inhibit ICa,V. Using immunoblot analysis and the PCR, we found evidence that RhoA, Rac1, and Cdc42 all are expressed in NG108-15 cells. Intracellularly perfused recombinant Rho-GDI (an inhibitor of guanine nucleotide exchange specific for the Rho family) attenuated the inhibition of ICa,V by BK. These findings indicate that activation of RhoA, Rac1, or Cdc42 may be required for the response to BK. To determine whether any of these monomeric G-proteins mediate the response to BK, we have intracellularly applied blocking antibodies specific for each of the candidate proteins. Only the anti-Rac1 antibody blocked the response to BK. In parallel experiments, peptides corresponding to the C-terminal regions of Rac1 and Cdc42 blocked the same response. These data indicate a novel functional contribution of Rac1 and possibly also of Cdc42 to the inhibition of ICa,V by neurotransmitters.

Animals↗
PubMed1997

Developmental expression of keratan sulfate-like immunoreactivity distinguishes thalamic nuclei and cortical domains.

Proteoglycans influence axonal outgrowth in several experimental paradigms, and their distribution during development suggests a role in axon guidance. We have used a monoclonal antibody, 5D4, that recognizes an epitope on sulfated keratans (KS), to define the distribution of keratan sulfate proteoglycans (KSPGs) in the developing thalamus and cortex of the rat. During development, 5D4 immunolabeling is present on thalamic axons as they grow through the internal capsule and subplate but is not present in the adjacent pathway for cortical efferent axons. Individual thalamic nuclei differ markedly in their expression of KSPGs; these distinctions persist throughout the period of developmentally regulated expression. Major cortical domains also differ in their expression of KSPGs, which are expressed throughout medial (cingulate and retrosplenial) cortex well before neocortex. Immunolabeling for KSPGs diminishes 2 weeks after birth; in the adult it is associated with small glia. The 5D4 epitope is present on several KSPGs (320, 220, and 160 kD) on Western blots during development but only in a broad 200-kD band in adult brain. Immunolabeling is degraded on sections and Western blots by keratanase II but not by keratanase I or chondroitinase ABC, confirming that the antibody recognizes KS. Bands identified by 5D4 on Western blots differ from those identified by antibodies to known KSPGs (aggrecan, claustrin, SV2, ABAKAN, phosphacan-KS), indicating that 5D4 is labeling KSPGs not previously described in the brain. The selective expression of KSPGs during development suggests that they may be a part of the molecular identity of thalamic nuclei and cortical domains that defines their connectivity.

Animals↗
PubMed1997

Structure-function studies of interleukin 15 using site-specific mutagenesis, polyethylene glycol conjugation, and homology modeling.

Interleukin (IL)-15 is a multifunctional cytokine that shares many biological activities with IL-2. This functional overlap, as well as receptor binding subunits shared by IL-15 and IL-2, suggests tertiary structural similarities between these two cytokines. In this study, recombinant human IL-15 was PEGylated via lysine-specific conjugation chemistry in order to extend the circulation half-life of this cytokine. Although PEGylation did extend the beta-elimination circulation half-life of IL-15 by greater than 50-fold, the biological activity of polyethylene glycol (PEG)-IL-15 was significantly altered. Specifically, PEG-IL-15 lost its ability to stimulate the proliferation of CTLL but took on the properties of a specific IL-15 antagonist in vitro. In comparing sequence alignments and molecular models for IL-2 and IL-15, it was noted that lysine residues resided in regions of IL-15 that may have selectively disrupted receptor subunit binding. We hypothesized that PEGylation of IL-15 interferes with beta but not alpha receptor subunit binding, resulting in the IL-15 antagonist activity observed in vitro. The validity of this hypothesis was tested by engineering site-specific mutants of human IL-15 as suggested by the IL-15 model (IL-15D8S and IL-15Q108S block beta and gamma receptor subunit binding, respectively). As with PEG-IL-15, these mutants were unable to stimulate CTLL proliferation but were able to specifically inhibit the proliferation of CTLL in response to unmodified IL-15. These results supported our model of IL-15 and confirmed that interference of beta receptor subunit binding by adjacent PEGylation could be responsible for the altered biological activity observed for PEG-IL-15.

Amino Acid Sequence↗
PubMed1997

Inhibition of tumor growth by peptide specific cytotoxic T lymphocytes in a three-dimensional collagen matrix.

Tumor associated, MHC I restricted antigenic peptides have been identified in both human and mouse tumors. Cytotoxic T lymphocytes (CTL) which recognize these tumor associated antigenic peptides are potential anti-cancer effectors. The anti-tumor activity of CTL is usually measured in vitro by the 51Cr release assay and in mice by tumor growth inhibition which is the most direct assessment of anti-tumor effect. In clinical studies, an in vivo tumor growth inhibition assay is not an option and an in vitro assay which corroborates with in vivo tumor growth is needed to assess the long-term outcome of CTL activity. Here, a three-dimensional (3-D) collagen gel assay was developed to measure in vitro the inhibition of mouse mammary tumor growth by anti-tumor CTL. BALB/c mouse CTL were induced with peptide E474 SFAVATTAL which was expressed by mouse mammary tumor cells D2F2. To measure D2F2 tumor growth inhibition in vitro, a mixture of tumor cells and anti-E474 CTL in a 1 microl cell bolus was embedded in the collagen gel. Complete eradication of tumor growth was observed at E:T ratio of or greater than 1:1. rIL-2 supplementation was necessary to achieve long-term tumor growth inhibition. Even spontaneous D2 tumor explant could be grown in the collagen gel and addition of anti-E474 to this culture reduced tumor growth. This assay system provides a realistic and sensitive alternative to the in vivo tumor growth inhibition assay and allows easy adaptation to test additional therapeutic reagents.

Animals↗
PubMed1997

[Prognostic factors and surgical results in traumatic cataract].

The visual outcome in 23 men and 2 women with traumatic cataracts was analyzed retrospectively. Their average age was 33 and they ranged from 10 to 69 years. Surgical results were either very good or very poor. Associated retinal injuries significantly decreased final visual acuity (p = 0.001). Those with initial visual acuity restricted to finger counting had better visual results than those with initial visual acuity restricted to light perception (p = 0.01) and hand motions (p = 0.02). Usually the lens was removed via the pars plana; the most common mode of optical correction was contact lenses.

Adolescent↗
PubMed1997

[Motor vehicle accidents and eye injuries].

The medical records of 24,632 patients treated in our surgical emergency service over a 3-year period were reviewed to determine the frequency and characteristics of ocular trauma caused by motor vehicle accidents (MVA). MVA-related injuries accounted for 13.9% of all visits to the service and involved 1106 of the patients (33%), of whom 77% were young males. At least 1 pathological finding was found in 858 (77.6%) and 169 (15.2%) were admitted. 16 patients sustained very severe ocular injuries which resulted in poor vision.

Accidents, Traffic↗
PubMed1997

Retinal arterial occlusion in a child with factor V Leiden and thermolabile methylene tetrahydrofolate reductase mutations.

PURPOSE: To analyze the potential cause of retinal arterial occlusion in a 9-year-old child. METHODS: Case report. Antithrombin III, protein C, free protein S, activated protein C resistance, and antiphospholipid antibodies in plasma were determined. Determination of factor V R506Q (Leiden mutation), thermolabile methylene tetrahydrofolate reductase by polymerase chain reaction, and restriction enzyme analysis were performed. RESULTS: The patient was found to be heterozygous for factor V R506Q (Leiden mutation) and homozygous for thermolabile methylene tetrahydrofolate reductase. CONCLUSION: Coexistence of two mild hereditary thrombophilic states may result in severe thrombotic manifestations in young people.

Child↗
PubMed1997

The economic cost of homicide in New Zealand.

Violence has become increasingly recognised as a public health issue, with significant impact on the health of individuals. In addition, there is increasing awareness that there are substantial economic costs associated with violence. The present study estimated the economic costs associated with homicide in New Zealand, using a human capital approach. Direct costs were assessed using information on incidence and costs from government agencies, and indirect costs were assessed based on loss of productivity resulting from death. The total estimated cost of homicides in 1992 was NZ $82997065 (U.S. $53948092), averaging NZ $1012159 per homicide (U.S. $657903). This total was comprised of the estimated total cost associated with homicide victims of NZ $37017010 (U.S. $24061056) and the estimated total cost associated with homicide perpetrators of NZ $45980055 (U.S. $29887035). Limitations of the incidence data and the methods employed suggest that these costs are likely to be underestimates. Nevertheless, the figure calculated represents an enormous drain on New Zealand's economic resources.

Adolescent↗