Occupational heat-related illness emergency department visits and inpatient hospitalizations in the southeast region, 2007-2011.

BACKGROUND: Heat-related illness (HRI) is an occupational health risk for many outdoor, and some indoor, workers. METHODS: Emergency department (ED) and inpatient hospitalization (IH) data for 2007-2011 from nine southeast states were analyzed to identify occupational HRI numbers and rates, demographic characteristics, and co-morbid conditions. RESULTS: There were 8,315 occupational HRI ED visits (6.5/100,000 workers) and 1,051 IHs (0.61/100,000) in the southeast over the study period. Out-of-state residents comprised 8% of ED visits and 12% of IHs. Rates for both, ED visits and IHs were significantly elevated in males and blacks. Younger workers had elevated rates for ED visits, while older workers had higher IH rates. CONCLUSIONS: This is the first study to evaluate occupational HRI ED visits and IHs in the southeast region and indicates the need for enhanced heat-stress prevention policies in the southeast. Findings from this study can be used to direct state health department tracking and evaluation of occupational HRI.

The range and nature of flexion-extension motion in the cervical spine.

OBJECTIVE: The full flexion to full extension angular ranges of motion (ROM) from C2 to C7 were measured for 78 normal subjects and 50 cervical myelopathic cases to examine the cervical motions for these two groups in a Chinese population. METHODS: Measurements were all taken from standard lateral radiographs. RESULTS: The normal group showed an average total ROM slightly less than in Western subjects, but a similar distribution of motion throughout C2 to C7. The proportion of motion at levels C4:C5 and C5:C6 were functions of the total ROM, the greatest proportion of motion being at C4:C5 for low (< 50 degrees) total ROM and moving to C5:C6 for high (> 90 degrees) total ROM. The myelopathic group showed a similar but less clearly established pattern of motion to this. A significantly lower average total ROM than in the normal group was also found. CONCLUSIONS: This work suggests that the reduction in total angular ROM concomitant with aging results in the emphasis of cervical flexion-extension motion moving from C5:C6 to C4:C5, both in normal cases and those suffering from cervical myelopathy.

Changes in cervical canal spinal volume during in vitro flexion-extension.

STUDY DESIGN: Quasistatic flexion and extension loads were applied in vitro to lower cervical spines. The flexion-extension motion produced was checked for physiologic relevance. OBJECTIVES: To examine the changes in the volume of the cervical spinal canal in flexion-extension motion. SUMMARY OF BACKGROUND DATA: Many papers have been published concerning the cervical canal volume as inferred from standard lateral radiographs. This study compares the inferred (radiographic) volumes and their changes to the physical changes within the spinal canal. METHODS: The lower cervical spines (C2-C7) from 10 cadavers were subject to stepwise flexion and extension in a purpose-built rig. Before this testing, the spinal cord was removed from the canal space of each specimen and replaced by a thin latex tube stoppered and secured at the opening of the canal (at C2) so that the volume of liquid displaced from the tube could be measured. This was done at each loading stage by means of a graduated glass column, and a radiograph of the spine was also taken to allow angular and displacement readings to be taken from C2 to C7. RESULTS: The average recorded change in volume of the spinal canal with flexion-extension motion was 1.9 ml, and showed a significant linear correlation with the dynamic canal width (r = 0.868, P < 0.05) and also with the total angle of flexion or extension (r = 0.979, P < 0.005). The volume of liquid displaced from the canal in lateral bending was much lower than that in flexion-extension motion, and only amounted to about 0.2 ml. The angular ranges of motion produced at each level were compared to previous results obtained in vivo, and no significant differences between the angular displacements found in vivo and in vitro under this experimental arrangement were seen. CONCLUSIONS: The loading regime described in this study causes angular displacements similar to those in vivo, and on this basis is a physiologically relevant loading pattern. The change in the volume of the spinal canal between C2 and C7 shows linear relationships with the angle of flexion and the dynamic canal width.

The response of articular cartilage to weight-bearing against metal. A study of hemiarthroplasty of the hip in the dog.

Hemiarthroplasty of the hip and some other joints has been used for many years with satisfactory results, but the fate of articular cartilage when weight-bearing against metal has not been reported. Replacement of the head of the femur was carried out in one hip of each of 26 dogs, and the changes in acetabular cartilage studied at intervals of up to 24 weeks. There was early loss of proteoglycan, followed by surface damage to the cartilage, progressive degenerative changes, and growth of pannus from the articular margins. At 24 weeks after operation there was little remaining articular cartilage, while intense subchondral activity suggested that the bony skeleton was being remodelled to conform to the shape of the prosthesis. This study is not intended to suggest that hemiarthroplasty does not help patients.

[Relationship between developmental stenosis of cervical spinal canal and spinal cord injury].

A retrospective study of 55 patients with acute cervical spinal cord injury caused by trauma was performed. On radiographic examination of the cervical spine in each of 55 cases showed no fracture or dislocation but developmental stenosis determined on lateral view radiograms. Ninety five point nine percent of this cases had block of the dyeing columns myelographically both in prone and supine positions. Eighty point nine percent of 47 cases demonstrated segmental instability of the cervical spine on full extension and flexion radiograms. Thirty eight cases suffered a minor trauma but resulted in incomplete spinal cord injury with moderate neurologic deficits. Most patients who had been treated conservatively for about 3 years demonstrated the neurologic deficits worsened gradually. In the later 50 cases underwent surgical treatment. A follow-up study showed that Robinson's procedure and laminectomy resulted in unsatisfactory outcome, in contrast to those of open-door technic. It is suggested that developmental stenosis may be a potential factor in the spinal cord injury.

[BMP1 fusion protein expressed in E. coli].

The expression plasmid pMS32C/BMP1 was constructed successfully by using recombinant DNA techniques. The validity of the reconstructed plasmid was confirmed by restriction map of PMS32C/BMP1 plasmid. Then the 66KD BMP1 fusion protein was highly expressed in E. coli, which accounting for 20% of total bacterial proteins. The expressed protein was purified by means of SDS-PAGE. The antiserum of BMP1 fusion protein was prepared by immunization of mice. The antisera immunoprecipitated with fusion protein and specifically bound to BMPs purified from human bone with high titer in immuno-dot assay. It is indicated that the BMP1 fusion protein contains human BMP moiety.

In vitro and in vivo induction of bone formation based on ex vivo gene therapy using rat adipose-derived adult stem cells expressing BMP-7.

BACKGROUND: Adipose-derived adult stem (ADAS) cells are multipotent cells capable of differentiating into osteoblasts, adipocytes and chondrocytes. The aim of this study was to determine whether BMP-7-expressing ADAS cells would elicit bone formation invitro and in vivo. METHODS: ADAS cells were harvested from Lewis rats and transduced with adenovirus carrying the recombinant human bone morphogenetic protein-7 (Ad-BMP-7) gene. Untransduced cells and cells transduced with adenovirus carrying the enhanced green fluorescence protein (Ad-EGFP) gene served as controls. BMP-7 expression was assessed by RT-PCR, immunofluorescence on day 1, and Western blot on days 4, 8 and 12. Alkaline phosphatase (ALP) activity was assayed on days 2, 4, 6, 8, 10 and 12. Osteocalcin production and bone nodule formation were detected by immunohistochemistry and von Kossa stain on day 12. A total of 1 x 10(6) cells mixed with type I collagen were implanted into the subcutaneous pocket in Lewis rat and subjected to histologic analysis 1, 2 and 4 weeks post-implantation. RESULTS: The Ad-BMP-7-transduced ADAS cells expressed BMP-7 at both mRNA and protein levels. ALP activity was detected in Ad-BMP-7-transduced cells from day 2 to day 12, peaking on day 8. Osteocalcin production and matrix mineralization further confirmed that these cells differentiated into osteoblasts and induced bone formation in vitro. Histologic examination revealed that implantation of BMP-7-expressing ADAS cells could induce new bone formation in vivo. DISCUSSION: ADAS cells would be a promising source of adult autologous stem cells for BMP gene therapy and tissue engineering.

[The preliminary result of osteoid callus allograft for bone healing].

OBJECTIVE: To investigate the feasibility of osteoid callus allograft as a kind of bone healing promoting materials. METHODS: The osteoid callus was obtained at one week after bilateral femoral fracture of a SD rat, then was kept at -196 C for 2 weeks. The bone defect model which bone repair was in intra-membranous osteogenesis was made at bilateral tibial shaft in 5 rats, and filled with the osteoid callus in the left defect area, the right side was filled with allogenous cancellous as control group. The specimen were processed with undecalcified technique and the sections were staining with light blue and sofranin T. RESULTS: After 2 weeks, there were cartilage and bone formation in the defect area of osteoid callus graft group(3/4), medullary cavity formation in bone tissue with cartilage arround it, fibrous tissues between new bone and host bone. While there were no cartilage or bone formation in the control group. CONCLUSION: The allograft osteoid callus is not absorbed by immunological rejection, but changed into bone tissue through endochondral osteogenesis. It is inspiring to develop osteoid callus allograft as a kind of material for bone healing.

Relationship between osteopenia and lumbar intervertebral disc degeneration in ovariectomized rats.

Ovariectomy (OVX) can cause bone loss in rats, but little is known about how it also induces lumbar intervertebral disc degeneration (LVD). This study investigated how estrogen deficiency affected intervertebral discs in OVX rats. Thirty 3-month-old female Sprague-Dawley rats were divided randomly into three equal groups. The baseline control group (BL) was killed at the beginning of the experiment. An ovariectomy was performed in 10 rats (OVX group) and another group of 10 rats was subjected to a sham surgery (Sham group). The OVX rats were untreated after the surgery to allow for the development of moderate osteopenia. Bone mineral density (BMD) measurement and bone histomorphometric analysis were applied to the segments of lumbar spines in all rats killed 6 months after surgery. The pathological changes of intervertebral discs were observed and the degree of LVD was scored by a histological scoring system. The BMD of the spines (L3-L5) in the OVX group decreased significantly compared with the Sham group. The bone volume indices in the OVX group were significantly lower, but the bone turnover rate parameters were significantly higher than those in the Sham group (P < 0.01). The histological scores for LVD in the OVX group were significantly higher than those in the Sham group (P < 0.01). There was a significant negative correlation between the BMD and Grade II discs in the OVX rats (P = 0.042). In conclusion, LVD occurs in the OVX rats and the degeneration of cartilage end plates may be a pathogenic factor in disc degeneration.

A codon 891 exon 15 RET proto-oncogene mutation in familial medullary thyroid carcinoma: a detection strategy.

A ser891ala RET proto-oncogene mutation has been previously discovered in a single kindred with familial medullary thyroid carcinoma (FMTC). An additional two probands with this mutation and with medullary thyroid carcinoma (MTC) without any other manifestations of MEN 2 have been identified. In one of thse families, two other individuals also had the mutant sequence and FMTC. Analysis of both cases showed cosegregation of the mutation and MTC. To facilitate detection of this mutation, a primer was engineered which creates a Hha I recognition site in the presence of the mutant sequence. As a result, this codon 891 exon 15 mutation can be identified with a restriction enzyme digestion.