Deformation behaviour of bovine cancellous bone.

Repetitive cyclic loading from daily activities is reported to induce fatigue damage and microcracking in bone structures. In terms of osteoporotic structures or in cases of serious damage of skeleton segments and the replacement by metallic implants the degree of damage due to cyclic loading will be even more pronounced. It is generally assumed that fatigue induced cracking and crack propagation essentially act as driving forces for complex physiological phenomena such as remodelling processes of bones and the adaptation to applied loads. In cases where the crack propagation rate exceeds the remodelling velocity, sudden and unexpected fracture of the bone is observed. Especially for implant reinforced structures the deviation in stiffness to the bone material can induce high peak stresses and accelerate crack propagation. Whereas, for cortical bone the mechanical behaviour under cyclic loading is sufficiently described, only rough data are available for trabaecular structures. In this study the deformation behaviour of bovine vertebra trabecular bone specimens is investigated under cyclic compressive loading. A powerlaw relationship was found between the applied load ratio and cycles to failure. A linear decrease of maximum, integral strains at failure with increasing applied load ratio was observed. Optical deformation measurement of the surface strains revealed that low strains (0-1 increasing applied load ratio whereby the higher strains behave directly opposite. This indicates that different failure mechanisms are acting at low cycle and high cycle fatigue, respectively.     

Case Study of Institution-Building by Nurse Bertha Wright and Colleagues

Purpose: To illuminate the history of nurses' participation in institution-building in the early 1900s, using the Baby Hospital in Oakland, California (now called Children's Hospital Oakland) as a case.
Design: Historical research using a framework of women's history theory focused on the women who founded Oakland's Baby Hospital, 1910–1930.
Method: Data collection included studying original sources, archival material, and interviews. Data evaluation included external criticism for authenticity and genuineness, and internal criticism for accuracy and bias.
Findings: In 1912, nurse Bertha Wright and social worker Mabel Weed, with a circle of community women, including Jessica Peixotto and Jean Howard McDuffie, established the Baby Hospital. Their activism included home visits, education, research, publications, political lobbying, and state policy and program development. At the center of this activity, was the lifelong commitment of Wright and Weed, who created new definitions of family. With social changes in the late 1920s, the male Board of Directors seized control of the hospital, and relegated women to auxiliary roles.
Conclusions: Health and social issues of the United States at the turn of the century are still problematic as a new century approaches and pertain to maternal-child health, foster care, and immigration. Feminists, including nurses, have played a central role in creating solutions. Knowledge of some of their incredible effort has been lost, particularly nursing's history in the western United States.     

Locked unifacet dislocation L3 on L4 vertebra. A case report

Unifacet dislocation of the lumbar spine, without fracture of the posterior elements on the opposite side, is a rare injury. A patient with this injury at the L3/L4 level is described. A satisfactory outcome was achieved using open reduction and internal fixation with plate and intrapeduncular screws.     

Glue embolisation of a ruptured pancreaticoduodenal artery aneurysm

Embolisation of a mycotic aneurysm of the anterior pancreaticoduodenal arcade was performed in an emergency situation using a microcatheter and tissue adhesive, after unsuccessful surgical therapy. The polymerising agent occluded the outflow vessel, the aneurysm and the feeding artery successfully. Correspondence to: F. Hammer     

Immunological studies on patients with tonsillar carcinoma: progress?

Of 101 consecutive cases of tonsillar carcinoma, 76 were finally selected as fulfilling the statistical requirement of the study. 25 of the cases were excluded because of deficiency of follow-up information. Actuarial survival time up to five years was compared with tumor staging and grading as well as with immunological parameters measured. Autologous and allogeneic anti-tumor antibodies were used for diagnostic purposes. Lymphocyte subpopulations, their distinction and in vitro function as suppressor cells was measured during the course of the disease. Actuarial five years survival time was 55%. Males contributed with 76% of the patients usually showing more progressed disease than females. Antibodies directed against tumor cells were found in all patients but not in healthy volunteers. A mean of 15% of immunofluorescence positive tumor cells revealed the best sensitivity, specificity and progressive value in terms of recurrencies. 5.8 months after reappearance of positive cells in the former operation area recurrencies could be proven histologically. 6.8 months later on the patients had died. Neither course of disease nor staging or grading of tumors showed a significant influence on lymphocyte subpopulations. In later stages in less differentiated tumors T-suppressor phenotypes showed an increase in numbers as compared to T-helper-cells. In parallel a significant rise of in-vitro suppressor activity of peripheral and lymph node lymphocytes could be detected. It is suggested that the rather good survival time is due to an intensive postoperative care and multiple hints from various immunological tests in addition to clinical signs. They allow to intensify directly the therapeutic and hygienic measures needed.     

A subgroup of patients with chronic pancreatitis overexpress the c-erb B-2 protooncogene.

OBJECTIVE: Chronic pancreatitis (CP) is a chronic condition associated with pancreatic fibrosis. A small subgroup of patients with CP develop enlargement of the head of the pancreas (EHP). This study examined some of the mechanisms that may lead to the development of EHP. SUMMARY BACKGROUND: The c-erb B-2 protooncogene encodes a 185-kDa transmembrane growth factor receptor (p185) that regulates cell growth and differentiation. METHODS: The authors analyzed c-erb B-2 expression in samples obtained from the head of the pancreas from 26 patients with CP (5 women, 21 men) using immunohistochemical and molecular technique. A diagnosis of CP with EHP was made when the vertical pancreatic head diameter was greater than 4 cm (14 patients), as determined by contrast-enhanced computed axial tomography scan. Pancreatic tissues from 15 healthy organ donors served as control subjects. RESULTS: In all patients without EHP and in the healthy control subjects, p185 immunoreactivity was present at low levels. In contrast, strong p185 immunoreactivity was observed in acinar and ductal cells in all patients with EHP. By in situ hybridization, c-erb B-2 messenger ribonucleic acid (mRNA) grains were expressed at high levels in patients with CP with EHP in both ductal and acinar cells. Northern blot analysis demonstrated a 4.5-fold increase (p < 0.001) in c-erb B-2 mRNA levels in patients with EHP compared with patients without EHP and healthy control subjects. Southern blot analysis did not reveal c-erb B-2 gene amplification or rearrangement. CONCLUSIONS: These findings indicate the c-erb B-2 is not overexpressed in most patients with CP. However, its overexpression in patients with CP with EHP suggest that c-erb B-2 may contribute to the pathophysiologic processes that lead to pancreatic head enlargement.