Macular pigment in the human retina: histological evaluation of localization and distribution

PURPOSE

Clinical investigations have demonstrated variation in both the peak optical density and the spatial distribution of macular pigment. To confirm these impressions histologically, the present study examined the distribution of macular pigment in the human retina.

MATERIALS AND METHODS

The macular retina of 11 donor eyes of different ages (28-91 years) were examined histologically on 100 microm vibratome sections directly, without further staining. Measurements were made in two dimensions: (1) adding the number of macular sections with visible macular pigment, and (2) direct measurement of the extension of macular pigment in the foveolar section, which visibly contained the most macular pigment.

RESULTS

The measurements with two methods demonstrated good correlation. The macula demonstrated a variation in the spatial extension of the visible macular pigment between 200 and 900 microm diameter around the centre of the fovea, which was also found when direct measurements were taken. There was no correlation with the donor age. The main location of macular pigment was in the layer of the fibres of Henle in the fovea and in the inner nuclear layer at the parafoveal site.

CONCLUSIONS

Histologically, a wide variation of the spatial distribution of macular pigment was found that confirms clinical observations. The primary localization of human macular pigment is in the inner retinal layers.

Current treatment options and biology of peritoneal mesothelioma: meeting summary of the first NIH peritoneal mesothelioma conference

Peritoneal mesothelioma is a rare cancer of the peritoneum with about 250 new cases diagnosed each year in the United States. It is the second most common site for mesothelioma development and accounts for 10-20% of all mesotheliomas diagnosed in the United States. A meeting sponsored by the NIH Office of Rare Diseases was held in Bethesda, Maryland on September 13 and 14, 2004. The objective of this meeting was to review the epidemiology, biology and current surgical and medical management of peritoneal mesothelioma. In addition, the meeting also discussed clinical and pre-clinical evaluation of novel treatments for mesothelioma as well as ongoing laboratory research to better understand this disease. This report summarizes the proceedings of the meeting as well as directions for future clinical and basic research.

Cytomegalovirus remains viable in naturally infected breast milk despite being frozen for 10 days

Cytomegalovirus culture positive breast milk was obtained from four mothers of very premature babies. The milk was stored at 0-5 degrees C in a domestic refrigerator for 48 hours or frozen for different durations at -20 degrees C. Cytomegalovirus survived in breast milk despite being frozen for 10 days at -20 degrees C.

Use of remifentanil for tracheal intubation for caesarean section in a patient with suxamethonium apnoea

A parturient presented for elective caesarean section with a history of multiple spinal operations and scoliosis and a biochemical diagnosis of suxamethonium apnoea. She declined any attempt at regional anaesthesia. We describe the use of a thiopental/remifentanil technique to relax the larynx and provide rapid and excellent conditions for laryngoscopy and tracheal intubation. The parturient awoke following an uneventful caesarean section with excellent pain relief and no recall. The baby had normal Apgar scores and umbilical blood gas measurements.

Randomized controlled trial of assertive community treatment in intellectual disability: the TACTILD study

BACKGROUND

There has been a policy shift away from hospital to community in the services of all those with psychiatric disorders, including those with intellectual disability (ID), in the last 50 years. This has been accompanied recently by the growth of assertive outreach services, but these have not been evaluated in ID services.

METHOD

In a randomized controlled trial we compared assertive outreach with 'standard' community care, using global assessment of function (GAF) as the primary outcome measure, and burden and quality of life as secondary measures.

RESULTS

We recruited 30 patients, considerably less than expected; no significant differences were found between the primary and secondary outcomes in the two groups. The differences were so small that a Type II error was unlikely.

CONCLUSIONS

Reasons for this lack of specific efficacy of the assertive approach are discussed and it is suggested that there is a blurring of the differences between standard and assertive approaches in practice.

Management strategies for a eutrophic water supply reservoir--San Roque, Argentina

Possible management strategies to improve water quality in a eutrophic water supply reservoir in Argentina were evaluated using the one-dimensional coupled hydrodynamics and water quality model DYRESM-CAEDYM. The model was used to determine the effects of several different artificial destratification system designs (including both bubble plume diffusers and surface impellers with draft tubes, both separately and in combination), on the biomass of the potentially toxic cyanobacteria Microcystia aeruginosa. The best results were found by using a combination of a deep and shallow diffuser, to break down the seasonal thermocline and therefore limit sediment nutrient release and anoxia, and to enhance vertical mixing in the surface mixed layer, respectively.