Influence of Documented Lead Poisoning on Environmental Modification Programs in Newark,New Jersey

Data from the Newark, New Jersey Childhood Lead Poisoning Program suggest that the major consequence of the program has been early intervention rather than the amelioration of environmental contamination. During 1975 to 1976, the authors investigated housing for 253 black and Hispanic children with blood levels over 60 Mg/100 ml. Of these, 115 had moved or had given incorrect addresses and were lost to follow-up, 22 were in the same homes but did not make themselves available and in 16 instances, the houses were boarded up or had been destroyed by fire. Of the remaining 100 children, 31% suffered from symptoms potentially related to lead poisoning and 57% of the children were still living in the same dwelling in which the c h id was affected. Only one-fourth of the houses had been properly abated, i. e., the problem of environmental lead had been corrected, and one-fourth of the houses were not investigated at all by health authorities. These data support the concern that lead poisoning will not be effectively combated until the environmental issue is fully addressed.     

Pinus plantation establishment in Queensland: III. Site preparation design

In Queensland, site preparation design is the stage of planning for Pinus plantation establishment, during which both watershed protection and runoff management needs are met, and runoff control systems and the boundaries for different site preparation systems are located in the field. The aims and methods of site preparation design are described in this paper.     

Integration in Interorganizational Hospice Care Systems

Hospice programs currently have a need to improve the integration of their services across organizational and professional boundaries. Coordination of decision making and client flow patterns are defined in this paper as integrative mechanism which must be employed by all hospice programs which are interorganizational in nature: that is, the program is delivered by a cluster of agencies providing care to the same population of patients. Also discussed are four system characteristics which determine the choice of these integrative mechanisms: scope of service, intensity of service, centrality of the system, and division of labor. The results of an empirical study of two different hospice service delivery systems indicate that as scope and intensity increase, the amount of integration must increase also. If it does not, the findings suggest that a “poor fit” results. It is shown that service integration fit can be measured by a discrepancy score: a high discrepancy is predictive of dissatisfaction with service effectiveness among hospice workers.     

In vitro and in vivo tissue repair with laser-activated chitosan adhesive

BACKGROUND AND OBJECTIVES: Sutures are currently the gold standard for wound closure but they are still unable to seal tissue and may induce scarring or inflammation. Biocompatible glues, based on polysaccharides such as chitosan, are a possible alternative to conventional wound closure. In this study, the adhesion of laser-activated chitosan films is investigated in vitro and in vivo. In particular we examine the effect of varying the laser power, as well as adding a natural cross-linker (genipin) to the adhesive composition. STUDY DESIGN/MATERIALS AND METHODS: Flexible and insoluble strips of chitosan films (surface area approximately 34 mm(2), thickness approximately 20 microm) were bonded to sheep intestine using several laser powers (0, 80, 120, and 160 mW) at 808-nm wavelength. The strength of repaired tissue was tested by a calibrated tensiometer to select the best power. A natural cross-linker (genipin) was also added to the film and the tissue repair strength compared with the strength of plain films. The adhesive was also bonded in vivo to the sciatic nerve of rats and the thermal damage induced by the laser assessed 4 days post-operatively. RESULTS: Chitosan adhesives successfully repaired intestine tissue, attaining a maximum repair strength of 14.7+/-4.3 kPa (n = 30) at the laser power of 120 mW. The chitosan-genipin films achieved lower repair strength (9.1+/-2.9 kPa). The laser caused partial demyelination of axons at the site of operation, but the myelinated axons retained a normal morphology proximally and distally. CONCLUSIONS: The chitosan adhesive effectively bonded to tissue causing only localized thermal damage in vivo, when the appropriate laser parameters were selected.     

Structural and molecular analyses of bone bridge formation within the growth plate injury site and cartilage degeneration at the adjacent uninjured area

Injury to the growth plate is common and yet the injured cartilage is often repaired with undesirable bony tissue, leading to bone growth defects in children. Using a rat tibial growth plate injury model, our previous studies have shown sequential inflammatory, fibrogenic, osteogenic and bone maturation responses involved in the bony repair. However, it remains unclear whether there is progressive accumulation of bone within the injury site and any potential degenerative changes at the adjacent non-injured area of the growth plate. This study examined effects of growth plate injury on the structure, composition and some cellular and molecular changes at the injury site and adjacent uninjured area. Micro-CT analysis revealed that while the bone volume within the injury site at day 14 was small, the bone bridge was considerably larger at the injury site by 60 days post-injury. Interestingly, formation of bone bridges in the adjacent uninjured area was detected in 60% of injured animals at day 60. Immunohistochemical analyses revealed reduced chondrocyte proliferation (PCNA labelling) but increased apoptosis (nick translation labelling) in the adjacent uninjured area. RT-PCR analysis on adjacent uninjured growth plate tissue found increased expression of osteocalcin at day 60, differential expression of apoptosis-regulatory genes and alterations in genes associated with chondrocyte proliferation/differentiation, including Sox9 and IGF-I. Therefore, this study has demonstrated progressive changes in the structure/composition of the injury site and adjacent uninjured area and identified cellular and molecular alterations or degeneration in adjacent uninjured growth plate in response to injury.     

Left ventricular function during interval and steady state exercise.

PURPOSE: Interval training (INT) is a commonly used method of exercise training in both athletic and clinical populations. Although we generally understand left ventricular (LV) function during steady state (SS) exercise, there are no data regarding LV function during INT. METHODS: We studied eight healthy, physically active volunteers during upright cycle ergometry during 15 min of both SS and INT, at the same average power output (90% individual anaerobic threshold), using first pass radionuclide ventriculography. During INT (60s/60s), measures of LV function were made during work (220 W) after 4 and 12 min and during recovery (120 W) after 7 and 15 min. These were compared with the average of four temporally matched measures made during SS (170 W). RESULTS: During INT, LV ejection fraction increased from rest (67 +/- 6%) to 77 +/- 5, 80 +/- 5, 77 +/- 5 and 79 +/- 4% after 4, 7, 12, and 15 min, respectively. During SS, LV ejection fraction was not significantly different at rest (70 +/- 4%) or during exercise (76 +/- 4, 79 +/- 4, 80 +/- 3, and 81 +/- 3%) after 4, 7, 12, and 15 min, respectively. Other measures of LV function (HR, BP, LV volumes, cardiac output, systemic vascular resistance, peak emptying, and filling rates) were likewise similar during temporally matched measurements during INT and SS. CONCLUSIONS: Although there were the expected transitions of ejection fraction with work and recovery, the overall hemodynamic picture during INT was very similar to SS. These data suggest that LV function during INT is not substantially different to that during SS.