Impact of implant number,distribution and prosthesis material on loading on implants supporting fixed prostheses

Summary  The purpose of this study is to evaluate axial forces and bending moments (BMs) on implants supporting a complete arch fixed implant supported prosthesis with respect to number and distribution of the implants and type of prosthesis material. Seven oral Brånemark implants with a diameter of 3.75 mm and a length of 13 and 7 mm (short distal implant) were placed in an edentulous composite mandible used as the experimental model. One all‐acrylic, one fibre‐reinforced acrylic, and one milled titanium framework prosthesis were made. A 50 N vertical load was applied on the extension 10 mm distal from the most posterior implant. Axial forces and BMs were measured by calculating signals from three strain gauges attached to each of the abutments. The load was measured using three different models with varying numbers of supporting implants (3, 4 and 5), three models with different implant distribution conditions (small, medium and large) and three models with different prosthesis materials (titanium, acrylic and fibre‐reinforced acrylic). Maximum BMs were highest when prostheses were supported by three implants compared to four and five implants (P < 0.001). The BMs were significantly influenced by the implant distribution, in that the smallest distribution induced the highest BMs (P < 0.001). Maximum BMs were lowest with the titanium prosthesis (P < 0.01). The resultant forces on implants were significantly associated with the implant number and distribution and the prosthesis material.     

The use of non‐invasive ventilation for life‐threatening asthma attacks: Changes in the need for intubation

Background and objective: Although non‐invasive ventilation (NIV) has been shown to be effective in a wide variety of respiratory diseases, its role in severe asthma attacks remains uncertain. The aim of this study was to clarify the effectiveness of NIV in patients experiencing severe attacks of asthma. Methods: A retrospective cohort study was performed, comparing the periods November 1999–October 2003 (pre‐introduction of NIV) and November 2004–October 2008 (post‐introduction of NIV). The data and clinical outcomes for patients who experienced severe attacks of asthma, and who fulfilled the inclusion criteria, were retrieved and compared. Results: Fifty events (48 patients) from the pre‐NIV period and 57 events (54 patients) from the post‐NIV period, which required hospitalization, were included in the analysis. Nine of the 50 pre‐NIV events (mean PaO₂/fraction of inspired O₂ (FiO₂) 241 ± 161; PaCO₂ 79 ± 40) were treated primarily by endotracheal intubation (ETI), while 17 of the 57 post‐NIV events (PaO₂/FiO₂ 197 ± 132, P = 0.39; PaCO₂ 77 ± 30, P = 0.95) were treated primarily by NIV. The rate of ETI decreased in the post‐NIV period (2/57 (3.5%) vs 9/50 (18%), P = 0.01). NIV was started earlier than mechanical ventilation (MV) with ETI (mean time interval between arrival and start of MV 171.7 ± 217.9 min vs 38.5 ± 113.8 min for NIV, P < 0.05). In the post‐NIV cohort, there was a trend towards a reduction in the duration of MV with ETI or NIV (36.9 ± 38.4 h vs 20.3 ± 35.8 h, P = 0.09), and hospital stay was shortened (12.6 ± 4.2 vs 8.4 ± 2.8 days, P < 0.01). No deaths occurred during this period as a consequence of asthma attacks. Conclusions: The need for ETI in patients with severe attacks of asthma was decreased after introduction of NIV. The ready availability of NIV enabled the rapid commencement of MV and may decrease the need for ETI. NIV is an acceptable and useful method of stabilizing patients experiencing severe attacks of asthma.     

Handicapped babies: how midwives cope

Research into families with a handicapped child produces numerous examples of the inadequate ways medical personnel inform parents of their child's condition. In the case of the abnormal neonate, midwives have a part to play in this communicating process; thus helping to lay the foundations for satisfactory adjustment by the parents. This paper suggests that midwives need more appropriate training in this important role.     

Successful autologous bone marrow transplant for relapsed Ki-1 lymphoma

We report on a 16 year old girl with relapsed Ki-1 lymphoma and a very poor prognosis. The initial manifestation was multiple bone metastases and lymphadenopathy. The patient achieved remission with modified adriamycin, bleomycin, vincristine, daunomycine therapy. However, 14 months after the completion of therapy, relapse occurred in a new cervical lymph node on the left side. After preparation with chemotherapy and total lymphoid irradiation (TLI) the patient underwent autologous bone marrow transplantation (A-BMT). Ki-1 lymphoma shows clinically diverse symptoms, but hematopoietic stem cell transplantation should be performed in relapsed cases. It may be effective to give TLI followed by A-BMT for patients such as ours who have lymph node involvement without bone marrow metastasis.     

In situ hybridization studies of stromelysin and tissue inhibitor of metalloproteinase 1 in IgA nephropathy

Summary: Accumulation of the extracellular matrix (ECM) in IgA nephropathy (IgAN) is thought to cause deterioration of glomerular function. Stromelysin and tissue inhibitor of matrix proteinase 1 (TIMP1) may play an important role in the turnover of the glomerular ECM. However, the expression of these enzymes in human renal tissues remains undefined. In the present study, non-radioactive in situ mRNA hybridization, which permitted the analysis at a cellular level, was performed to localize stromelysin and TIMP1 in renal tissue of IgAN. We also determined the percentage of cells positive for stromelysin or TIMP1 mRNA among intraglomerular cells. A total of 16 patients with IgAN were examined, including eight patients with severe histopathological changes and eight with mild changes. Three patients without glomerular disease were also studied. Stromelysin and TIMP1 mRNA were weakly expressed in the mesangium of normal kidneys and IgAN renal tissues with mild damage. However, the expression of both mRNA was significantly increased in the area of mesangial proliferation, in glomerular epithelial cells and in Bowman's capsule of advanced lesions. Several cells in the area of mesangial proliferation were double positive for stromelysin and TIMP1 mRNA, while certain cells positive for stromelysin mRNA did not express TIMP1 mRNA. In the interstitium, epithelial cells of certain tubules and some mononuclear cells were positively stained for these mRNA, especially in advanced lesions. Our results indicated that stromelysin and TIMP1 genes were expressed in glomerular resident cells, tubular epithelial cells and infiltrated mononuclear cells in IgAN, and their expression was enhanced in advanced tissue damage. the demonstration of a co-expression and discordant expression of the genes indicates that each gene expression may be regulated in a cell type-specific manner and that it could also be altered by cellular environmental factors.     

Investigation of melena and hematochezia as the chief complaint of gastrointestinal bleeding in pediatric surgical patients

The causes of melena or hematochezia in 48 pediatric patients were examined. Malrotation with volvulus was an important cause of hemorrhage during the newborn period, and intussusception was very typical in patients aged from 1 month to 1 year. Polyps of the rectum and colon were the most common causes of melena or hematochezia in patients older than 1 year. No cause of melena or hematochezia could be identified in 11 children. Ten patients have remained in good health with no further episodes of melena or hematochezia. Localized multiple polyps of the rectum with focal carcinoma were detected in only one patient. In general, although no further investigation is required after detection of the cause of bleeding and its successful treatment, it should be kept in mind that gastrointestinal malignancy can occur in children.     

Cardiac Pacemaker Regulated by Respiratory Rate and Blood Temperature

A new method using respiratory rate and temperature as the guides for optimal pacing is proposed. A pacemaker was fabricated which senses these two parameters simultaneously. The pacemaker functions by calculating the cardiac rate, which would be derived from the respiratory rate and the blood temperature. The higher of the two rates is adopted as the cardiac pacing rate, i.e., at which stimuli will be delivered. The operation was tested in a mongrel dog with complete atrioventricular block. After the induction of anesthesia, a thermistor temperature probe was inserted into right atrium and a respiratory rate sensor was attached around the chest. After administration of a pyrogenic drug, both respiratory rate and blood temperature increased. The pacing rate was increased from 178 beats/minute(bpm) at 36.4 degrees C, blood temperature, and 26.5 acts/minute(apm), respiratory rate, to 233 bpm at 40.1 degrees C and 40.0 apm. Cardiac output was increased from 2.15 liters/minute(l/pm) at the beginning to 2.50 l/pm at maximum. The transition of the guide from respiratory rate to temperature was observed at about 38 degrees C.