PubMed Health⌕ Search

Biomedical subjects

H Herzberg

Publications and source records attributed to H Herzberg.

11 recordsLinked to original sources

A normative study of step vergence in elementary schoolchildren.

The purpose of this study was to develop normative data for step vergence testing in children age 6-12. Such data are not currently available for this age group. Base-in and base-out step vergence testing with a prism bar was performed on 386 elementary schoolchildren who had all passed a modified clinical technique (MCT) screening. A new polarized target was developed which enabled us to detect suppression, as well as diplopia or blur. The findings suggest significant differences from normative data previously reported for adults. Because the data for 6-year-olds were different from the rest of the group, we suggest that lower norms be used for this age group. This study provides expected findings for step vergence testing outside the phoropter, which can be used clinically for the assessment of disparity vergence ranges in young children.

Child↗

Normative study of accommodative facility in elementary schoolchildren.

Although accommodative facility testing is used widely in the evaluation of accommodation in children, published normative data are not available for this age group. Current values being used are based upon studies of adult populations. In order to establish norms, 542 elementary schoolchildren were screened. Those that passed a specific set of criteria were included in the accommodative facility assessment. We used a new target and instructional set, which took into consideration the problems associated with subjective testing of young children. The results revealed lower mean accommodative facility values for both monocular and binocular accommodative facility than the values obtained previously from adult populations. These new findings can be used as a clinical guide to evaluate accommodative facility in young children.

Accommodation, Ocular↗

Effects of partial hepatectomy on the immune responses in mice.

Experiments were performed to investigate the immune responses occurring as a result of partial hepatectomy (HEP) in mice. On Day 12 mice subjected to HEP showed a twofold rise in serum levels of IgG when compared with sham-operated (ShO) controls. The effects of HEP on specific antibody production following a single immunization with sheep red blood cells (SRBCs) were investigated. An early appearance of direct (IgM) splenic plaque-forming cells (PFCs) and significantly elevated indirect (IgG) PFCs were found in HEP mice. Elevated, early-appearing mercaptoethanol-resistant (IgG) hemagglutinating antibodies were also demonstrated in the sera of HEP mice. In addition to these findings our study showed that humoral and cell-mediated responses are affected by HEP in opposing fashion. Partial hepatectomy performed immediately after skin grafting suppressed a first set allograft rejection in mice. Furthermore, inhibited delayed-type hypersensitivity (DTH) response against SRBCs, as evaluated by a footpad weight assay, was demonstrated in HEP mice compared with the ShO controls. When SRBC-primed mice were partially hepatectomized 15 days later, they responded in a manner typical of the secondary immune response, showing an increased production of indirect (IgG) splenic PFCs. A similar anamnestic response was observed in mice sensitized with leptospiral antigen 50 days prior to HEP or exposed to carbon tetrachloride (CCl4) hepatotoxin. The mice responded by elevated serum IgG-specific antibodies as measured by solid-phase enzyme-linked immunosorbent assay (ELISA). Since HEP induced in mice immunological disturbances similar to those associated with liver disease, it is suggested that partial hepatectomy creating liver deficiency followed by regeneration may be a useful experimental model to study the immune status of various forms of hepatic damage.

Animals↗