AC/A ratios in myopic and emmetropic Hong Kong children and the effect of timolol§

Purpose: Caucasian children with myopia have elevated response accommodative vergence to accommodation (AC/A) ratios. The purpose of this study was twofold: to determine if response AC/A ratios vary with refractive error and with myopic progression rate in Hong Kong Chinese children, and to determine the effect of beta‐adrenergic antagonism with topical timolol application on AC/A ratios. Methods: Thirty children aged eight to 12 years participated in the study. All refractive errors were corrected with spectacle lenses. Accommodative responses were measured using a Shin‐Nippon autorefractor and concurrent changes in vergence were assessed using a vertical prism and a Howell‐Dwyer card at three metres and 0.33 metre. Accommodative demand was altered using plus or minus two dioptre lenses and lens‐ and distance‐induced response AC/A ratios were calculated. Measurements were repeated 30 minutes after the instillation of topical timolol maleate (0.5 per cent). Results: AC/A ratios appeared higher in progressing myopic children but the difference was not statistically significant. Timolol application reduced accommodative convergence (AC) in the stable myopes (reduction = ‐3 ± 1.14^A) but not in the emmetropes (0.69 ± 0.9^P) or progressing myopes (0.16 ± 0.43^A) and this difference between refractive groups was statistically s ignificant (F^2,27= 3.766; P= 0.036). However, timolol did not produce a significant change in the accommodative response to positive or negative lenses or response AC/A ratios. Conclusions: We did not find that AC/A ratios in myopic Chinese children were elevated and therefore, it is unlikely that elevated AC/A ratios are responsible for the high levels of myopia that occur in Hong Kong. The finding that timolol reduced AC in the stable myopes suggests that the autonomic control of accommodative convergence in these children may be different from that in emmetropic children and those with progressing myopia.     

Activation of guinea pig eosinophil respiratory burst by leukotriene B4: role of protein kinase C

Leukotriene B4 (LTB4) and the protein kinase C activator, 4-beta-phorbol dibutyrate (PDBu), both induced a pronounced and concentration-dependent stimulation of hydrogen peroxide (H2O2) generation by purified guinea pig peritoneal eosinophils in the concentration range 1 nM-1 microM. The LTB4 response was inhibited competitively by the specific LTB4 receptor antagonist, U-75302, with a KB of 25 nM, while the concentration-response curves for both stimuli were shifted rightwards (3.8-fold and 2.8-fold for LTB4 and PDBu, respectively) by the competitive protein kinase C inhibitor, 1-O-hexadecyl-2-O-methylglycerol at a concentration of 300 microM. LTB4 appears, therefore, to induce respiratory burst in eosinophils via a receptor-mediated mechanism involving protein kinase C.     

Terminal deletion (14)(q32.3): a new case.

A mildly dysmorphic, 2 year old girl with mental retardation was found to have a small de novo terminal deletion of the long arm of chromosome 14, del(14)(q32.3). She was found to have features in common with two previous terminal deletion cases and particularly with the well documented ring 14 syndrome, although seizures, a characteristic feature of ring 14, were notably absent.     

Chloroform toxicity in mice: correlation of renal and hepatic necrosis with covalent binding of metabolites to tissue macromolecules

Chloroform (CHCl₃) treatment caused centrolobular hepatic necrosis in mice of both sexes whereas renal necrosis was observed only in male mice. Following administration of ¹⁴CHCl₃ to mice, substantial amounts (about 3 mmole/g) of radiolabeled material were covalently bound to proteins in the liver and kidney. The amount of convalent binding paralleled the extent of renal and hepatic necrosis both in normal animals and in male mice pretreated with either phenobarbital or piperonyl butoxide, agents which induce or block, respectively, microsomal drug metabolizing enzymes. These results suggest that the covalent binding is due to a metabolite of CHCl₃. Evidence that the covalent binding is causally related to the tissue necrosis was obtained from autoradiograms showing that the radioactivity is located mainly in the necrotic lesions.     

Autoradiographic localization of putrescine uptake to type II pneumocytes of rabbit lung slices

At low concentrations (0.4-5.0 microM), the polyamine, putrescine, is accumulated predominantly by a saturable process in rabbit lung slices. The question of why the lung should possess polyamine transport capabilities and the known cellular compartmentalization of various other pulmonary functions prompted us to investigate whether putrescine uptake was localized to a specific cell type(s) within rabbit lung. Localization of putrescine uptake in rabbit lung was investigated by frozen and plastic section autoradiography, combined with electron microscopy. Rabbit lung slices were incubated with [3H]putrescine at a concentration (0.4 microM) at which the saturable component of uptake predominates. Both frozen and plastic section autoradiograms revealed relatively minor amounts of radiolabel associated with either vascular or bronchiolar tissues, whereas a greater density of radiolabel was present over the alveolar epithelium. Highly localized areas of radiolabel were found at the junctions of adjacent alveoli and these labeled cells were identified by electron microscopy as type II pneumocytes. We conclude that the type II pneumocyte is a major site of putrescine uptake in rabbit lung slices. Our study also indicates that different rabbit lung cell types possess differing abilities to accumulate putrescine.     

A community based lesbian sexual health service - clinically justified or politically correct?

Lesbian sexual health care is still a neglected issue. In order to address this, a needs assessment was carried out in Glasgow amongst the lesbian community and 200 responses were received. More than 40% of the respondents said they were unable to disclose their sexual orientation to their GP and were unable to discuss sexual health issues with them. Eighty-one percent said there was a need for a lesbian sexual health service and 71% said they would use such a service if it existed. Therefore a pilot clinic was set up in Glasgow and was co-ordinated by a multidisciplinary advisory group. The clinical component of the service was audited and it was found that gynaecology and fertility issues were the most common presenting condition (52%), followed by psychosocial issues (26%). Genitourinary problems, such as vaginal discharge, constituted 20% of presentations. Client satisfaction with the clinic was high. This pilot service showed that areas of sexual health care, such as the need for inclusion in cervical smear programmes and equality of access to assisted conception, are issues which are important to this minority group and which need to be addressed. The clinic is now ongoing as a result of the pilot scheme and is the only family planning based lesbian health service in the UK.     

Characterization of the procoagulant chain derived from human high molecular weight kininogen (Fitzgerald factor) by human tissue kallikrein

Human high molecular weight kininogen (HMWK), a single-chain protein with mol wt 120,000, is cleaved by human urinary kallikrein (HUK) to release kinin from within a disulfide loop and form a two-chain protein that retains all the procoagulant activity of the native molecule. Cleavage of HMWK by HUK is associated with a reduction in size to mol wt 115,000, as assessed by SDS-PAGE of unreduced protein, whereas the two chains of the reduced protein present together as a single broad band with mol wt 64,000. The 64,000 chain with procoagulant activity was chromatographically separated from the nonfunctional chain of similar size. The homogeneous procoagulant chain had an amino acid composition similar to that of smaller procoagulant ("light") chains isolated by others upon cleavage of HMWK with plasma kallikrein and elicited an antiserum that was monospecific by Ouchterlony analysis and inhibited the procoagulant function of HMWK. Thus, the limited proteolysis of HMWK by HUK has permitted, for the first time, the isolation of a stable procoagulant chain that is equal in size to the nonfunctional chain. The common terminology of "heavy" and "light" chain for kinin-free kininogen obtained with plasma kallikrein reflects the continued degradation of the procoagulant carboxyterminal chain and is not appropriate for the initial two-chain product formed when kinin is released from HMWK. It is proposed that the initial cleavage products of HMWK be designated the A-chain, the B-fragment, and the C- chain, representing the amino-terminal chain, the released vasoactive peptide containing the bradykinin sequence, and the carboxy-terminal procoagulant chain, respectively. Thus, intact HMWK would contain, in sequence, A, B, and C regions.     

Wound infection,dressings and pain,is there a relationship in the chronic wound?

The focus on quality of life issues in wound care has justly taken a far greater importance. With the acceptance that pain can be a major factor to the patient, and in particular, pain at dressing change comes the opportunity for avoidance and/or reduction strategies. Whilst pain has been associated with wound infection for millennia, it is only much more recently that this has received due attention from research and clinical practice. In this study, the nature of pain, changes in pain and pain associated with infection are the focal points. A Delphi approach, now a frequently used tool in wound care research, has been used to obtain expert opinion on these aspects of management.