Use of densitometric examination after cemented total knee arthroplasty

Background. Dual energy X-ray absorptiometry (DXA, DEXA) is one of many ways of measuring bone mineral density (BMD). Considering the fact that it is possible using DXA analysis to distinguish metal elements from bone, this method seems to be optimal in the assessment of bone mineral density in the area of an inserted implant. The aim of our study was to examine the usefulness of DXA examination of the knee joint area after cement arthroplasty. Material and methods. A BMD analysis of four areas surrounding the knee prosthesis was performed using the author's own method. Results. After a series of densitometry analyses, the coefficient of variation (CV) and the least significant difference (LSD) were determined. Conclusions. DXA analysis of the knee joint after arthroplasty using the method described here shows high repeatability. Periodic DXA analysis of the vicinity of the knee prosthesis may be useful in assessing the dynamics of change occurring around the implant.     

Evidence That the Length of Bile Loop Determines Serum Bile Acid Concentration and Glycemic Control After Bariatric Surgery

Background

Bariatric surgery contributes to the improvement in glucose metabolism that may be related to a postoperative increase in serum bile acids (BAs). Three commonly used types of bariatric procedures, laparoscopic sleeve gastrectomy (LSG) (without creation of a bile loop), Roux-en-Y gastric bypass (RYGB), and omega-loop gastric bypass (OLGB) (with creation of shorter 100–150 cm and longer 200–280 cm bile loops, respectively), differ in their effects on glycemic control. The aim of the study was to compare the effects of various bariatric procedures on serum BA concentration and glucose homeostasis.

Methods

Serum BAs in 26 obese patients were determined by liquid chromatography-mass spectrometry prior to bariatric surgery, as well as 4 days and 3 months thereafter.

Results

Four days after the surgery, serum concentrations of BAs in LSG and OLGB groups were similar as prior to the procedure, and a slight decrease in serum BAs was observed in the RYGB group. Serum BA level in the LSG group remained unchanged also at 3 months after the surgery, whereas a significant 0.5- and 3-fold increase in this parameter was noted in the RYGB and OLGB groups, respectively. Serum concentration of BAs correlated positively with the length of the bile loop (R?=?0.47, p?<?0.05).

Conclusion

The evident improvement of glycemic control observed 3 months after OLGB might be associated with a postoperative increase in serum BAs, resulting from their better absorption from the longer bile loop. However, the changes in serum BAs probably had little or no impact on insulin sensitivity improvement at 4 days post-surgery.

     

Ileal Transposition (IT) Surgery Changing the Ultrastructure of the Transposed Segment as well as Jejunum. Histomorphometric and Electron Microscopy Analysis

Objective

Ileal transposition (IT) procedure leads to higher secretion of incretin hormones what is associated with a beneficial metabolic effect. However, IT will also have an influence on the related jejunum and ileum function. The aim of this research was to investigate the morphology of the jejunum and transposed ileum with the use of light and transmission electron microscopy (TEM) in order to determine the local alternations in the intestine resulting from the transposition.

Methods

Twenty male, 8-week-old, obese Zucker rats underwent IT and six of them sham surgery. To compare both groups, the transection was made at all corresponding ileum positions among both groups of animals. The ileal anastomoses among the rats of sham procedure were subsequently formed accordingly without IT. Three months following the surgery, the tissue samples of jejunum and ileum were harvested.

Results

A significant increase in villus length, a decrease in the crypt depth, and an increased thickness of mucosa-muscularis-serosa (MMS) as well as cellular hyperplasia, with increased mitochondrial density of the transposed ileum segment, were observed among the group of rats which underwent IT comparing to the ones undergoing sham surgery. In rats undergoing IT, microvillus degeneration in jejunum regions was observed.

Conclusions

Ileal transposition alters the morphology and ultrastructure of the ileum as well as the jejunum. Given that the microvillus membrane represents an important aspect of the enterocyte functions, a further biochemical and molecular research is necessary in order to assess whether the observed changes are beneficial or not and to explore the phenomenon of gut adaptability after metabolic surgery.

     

Engineering Analysis of Tricuspid Annular Dynamics in the Beating Ovine Heart

Functional tricuspid regurgitation is a significant source of morbidity and mortality in the US. Furthermore, treatment of functional tricuspid regurgitation is suboptimal with significant recurrence rates, which may, at least in part, be due to our limited knowledge of the relationship between valvular shape and function. Here we study the dynamics of the healthy in vivo ovine tricuspid annulus to improve our understanding of normal annular deformations throughout the cardiac cycle. To this end, we determine both clinical as well as engineering metrics of in vivo annular dynamics based on sonomicrometry crystals surgically attached to the annulus. We confirm that the tricuspid annulus undergoes large dynamic changes in area, perimeter, height, and eccentricity throughout the cardiac cycle. This deformation may be described as asymmetric in-plane motion of the annulus with minor out-of-plane motion. In addition, we employ strain and curvature to provide mechanistic insight into the origin of this deformation. Specifically, we find that strain and curvature vary considerable across the annulus with highly localized minima and maxima resulting in aforementioned configurational changes throughout the cardiac cycle. It is our hope that these data provide valuable information for clinicians and engineers alike and ultimately help us improve treatment of functional tricuspid regurgitation.     

In vivo interaction of beta-lactam antibiotics with the penicillin-binding proteins of Streptococcus pneumoniae.

The interactions of several beta-lactam antibiotics with the penicillin-binding proteins (PBPs) of Streptococcus pneumoniae have been studied using whole organisms treated with such antibiotics and subsequently with [3H]benzylpenicillin. Differences in chemical structure were shown to cause major and selective changes in the affinities of the beta-lactams for the PBPs Only 4 of the 28 compounds tested induced a specific morphological effect (enlargement of the equatorial region) under the particular conditions tested. In 12 of the 18 beta-lactams studied, a close correlation was found between the minimal inhibitory concentrations and the concentrations required to half-saturate PBP2b. However, such a correlation was no longer apparent when the bacteria were treated with the antibiotics at their minimal inhibitory concentrations. These findings are discussed in the context of various approaches that have been used to identify the growth-inhibitory targets of beta-lactam antibiotics in bacteria.     

Assessment of Synvisc treatment in osteoarthritis

Background. Viscosupplementation is a relatively new method for the treatment of osteoarthritis (OA). The main goal of this project was to assess the safety and clinical utility of Hylan G-F20 (Synvisc(R)) in the treatment of pain associated with osteoarthritis of the knee. The type and frequency of additional therapies used during Synvisc(R) treatment were also assessed. It was a prospective project designed for monitoring Synvisc(R)-prescribing habits in usual medical care.
Material and method. One hundred ninety knee joints in 187 patients were studied (OA symptoms were bilateral in 3 women). Synvisc(R) was indicated for the local treatment of pain in osteoarthritis of the knee. After the diagnosis, Synvisc(R) therapy was started at the recommended dose of 2 ml per intra-articular injection once
a week (at 1-week intervals), three injections in total. The data collected, including medical history, physical examination, radiographic examination and treatment efficacy (overall assessment performed at each visit), were recorded on case report forms designed to facilitate statistical analysis. The physicians completed visual Analogue Scale (VAS) for overall assessment of OA pain at each visit. The clinical outcome was recorded after the end of therapy. The patient data were collected by physicians taking part in this project only.
Results. In 156 cases (82.1%) either a substantial improvement or subsidence of symptoms was observed. In 34 cases (17.9%) the improvement was small or there was no change in the patient's condition. There were local adverse reactions in 2 patients (1.07%). There was no need to cease the treatment, to hospitalise a patient or to start any additional treatment. In 167 patients (89.3%) there was no need to start any non-pharmacological concomitant treatment.
Conclusions. In summary, Synvisc(R) viscosupplementation should be rated among the safest and most effective methods for the treatment of OA, for it alleviates OA-related pain, thus reducing the need for NSAIDs and steroid injections. The use of Synvisc(R) in OA patients alleviates pain regardless of sex and age, the effect being the most pronounced in patients with low- and medium-grade radiographic changes.     

Role of the T cell in the genesis of angiotensin II induced hypertension and vascular dysfunction

Hypertension promotes atherosclerosis and is a major source of morbidity and mortality. We show that mice lacking T and B cells (RAG-1^−/− mice) have blunted hypertension and do not develop abnormalities of vascular function during angiotensin II infusion or desoxycorticosterone acetate (DOCA)–salt. Adoptive transfer of T, but not B, cells restored these abnormalities. Angiotensin II is known to stimulate reactive oxygen species production via the nicotinamide adenosine dinucleotide phosphate (NADPH) oxidase in several cells, including some immune cells. Accordingly, adoptive transfer of T cells lacking the angiotensin type I receptor or a functional NADPH oxidase resulted in blunted angiotensin II–dependent hypertension and decreased aortic superoxide production. Angiotensin II increased T cell markers of activation and tissue homing in wild-type, but not NADPH oxidase–deficient, mice. Angiotensin II markedly increased T cells in the perivascular adipose tissue (periadventitial fat) and, to a lesser extent the adventitia. These cells expressed high levels of CC chemokine receptor 5 and were commonly double negative (CD3⁺CD4⁻CD8⁻). This infiltration was associated with an increase in intercellular adhesion molecule-1 and RANTES in the aorta. Hypertension also increased T lymphocyte production of tumor necrosis factor (TNF) α, and treatment with the TNFα antagonist etanercept prevented the hypertension and increase in vascular superoxide caused by angiotensin II. These studies identify a previously undefined role for T cells in the genesis of hypertension and support a role of inflammation in the basis of this prevalent disease. T cells might represent a novel therapeutic target for the treatment of high blood pressure.