Combined aortic and mitral valve repair in active infective endocarditis

We describe a case of successful combined repair of the aortic and mitral valves for an indication of active infective endocarditis involving both valves. Mitral valve repair was achieved by vegetation debridement, fixation of the anterior mitral commissure, resection and suturing of the posterior mitral leaflet, and posterior annuloplasty with autologous pericardium. Aortic valve repair was achieved by vegetectomy and commissural plication. Postoperative clinical course was without signs of recurrent infection, and echocardiogram demonstrated mitral valve competence with trivial aortic regurgitation. We concluded that simultaneous valve repair is a viable option in the context of active endocarditis.     

An alternative perspective to the immune response in autoimmune exocrinopathy: induction of functional quiescence rather than destructive autoaggression

Sjögren's syndrome is characterized by dryness of the eyes and the mouth due to mononuclear cell infiltration of the lacrimal and salivary glands. The aetiology is unknown but autoimmunity is considered to play a significant role in the pathogenesis. Recent studies have focused on the fact that tear and salivary flow involves an entire functional system that includes the mucosal surfaces with adnexes (the site of inflammation), efferent nerve signals sent to the midbrain (lacrimal and salivary response region), and afferent neural signals from the brain to the acinar/ductal epithelial structures in the gland. Mononuclear cell infiltration in exocrine glands can lead to glandular destruction, suggested to be mediated through apoptosis. However, the functional impairment of exocrine glands could be regulated by cytokines and/or antibodies against the muscarinic M3 receptor by inhibiting the neural stimulation of the residual glands. This review discusses the possibility that the pathogenesis of Sjögren's syndrome comprises aberrant immune-mediated neuro-hormonal events.     

Phenotypic shift in human differentiated gastric cancers from gastric to intestinal epithelial cell type during disease progression

Background. The phenotypic expression of tumor cells is widely thought to resemble that of the tissue of origin. In the present study, to assess phenotypic changes that occur with disease progression, we investigated human differentiated gastric cancers at different depths of invasion for component cancer cell types. Methods. Using a combined mucin histochemical and immunohistochemical approach, we classified surgical specimens of 301 differentiated gastric cancers into three types: gastric epithelial cell (G) type, intestinal epithelial cell (I) type and mixed gastric and intestinal (GI) type, according to the phenotypic differentiation of the component cancer cells. The relation between the phenotypic type of cancer and their depth of invasion was evaluated. Results. The proportion of G type cancers was 41.4% in early (tumor invasion of mucosa or submucosa) cases, decreasing to 22.2% in advanced (tumor invasion of muscularis propia or deeper) cases, whereas the proportion of I type cancers increased with progressive disease from 23.5% to 31.1% (P < 0.01). Cancers invading the subserosa or deeper included more I type cases and fewer G type than cancers limited to the mucosa (P < 0.01). In most cases of each phenotypic type, intestinal metaplasia was recognized in the surrounding background mucosa, but no clear relation was shown between the phenotype of cancers and the degree of intestinal metaplasia in the background mucosa, suggesting that intestinal metaplasia is not always a preneoplastic lesion. Conclusions. A phenotypic shift from G to I type expression was observed with the progression of human differentiated gastric cancers. Intestinalization may occur independently in cancerous and noncancerous gastric mucosa. Received for publication on May 1, 1998; accepted on Oct. 22, 1998     

Cathepsin K inhibitor causes changes in crystallinity and crystal structure of newly-formed mandibular bone in rats

Cathepsin K inhibitors are new drugs with the potential for the treatment of osteoporosis because they sustain bony remodelling better than bone resorption inhibitors such as bisphosphonates. The treatment of osteoporosis with inhibitors of bony resorption is associated with osteonecrosis of the jaw, as the deterioration in bony quality that they induce is thought to be one of its causes. The quality of bone is delineated by structural and material characteristics (which include the degree and quality of mineralisation, and depends on the content of proteoglycan and the structural integrity of the bony collagen).^1,2 Animal and clinical studies have shown that cathepsin K inhibitors improve the mineral density and structural characteristics of bone, but their effect on the rest remains unknown. We therefore hypothesised that these inhibitors will affect the material characteristics of newly-formed mandibular bone. To verify our hypothesis, we used Raman microspectroscopy to examine such bone in rats that were given a cathepsin K inhibitor, and found unusual crystallinity and an increased substitution of carbonate (CO₃^2?) in its crystal structure.     

Comparison of the diagnostic power of transthoracic and transesophageal echocardiography to detect ruptured chordae tendineae

Preoperative information concerning the severity and etiology of MR is very important for selecting the most appropriate surgical strategy. Ruptured chordae tendineae (RCT) are one of the most important preoperative findings. We compared the diagnostic power of transesophageal echocardiography (TEE) and transthoracic echocardiography (TTE) to detect RCT in patients with MR. We studied 61 patients with MR (30 men, 31 women; mean age, 61 ± 12 years) who underwent mitral valve repair or replacement. Both TTE and TEE were performed before the operations, and the sensitivity and specificity of TTE and TEE to detect RCT were determined. In addition, other factors that influenced the detection of RCT by these two methods were investigated. At the time of an operation, RCT was confirmed in 39 of 61 cases. Transesophageal echocardiography had a higher sensitivity than TTE (74% versus 44%; P = 0.006) to detect RCT, although the specificity was not significantly different. In patients with a body mass index (BMI) > 22 (P = 0.023) or MR grade 4 (P = 0.026), TEE had a significantly higher diagnostic sensitivity than TTE, although there was no significant difference in patients with BMI < 22 or MR grade ≤ 3. In the lateral and medial segments of the mitral valve, TEE had a significantly higher diagnostic sensitivity to detect RCT than TTE (P = 0.0012), although there was no significant difference in the middle segments. There was no significant difference between TTE and TEE with respect to the sensitivity to detect RCT in myxomatous mitral valves. Although the sensitivity of TEE was higher than that of TTE to detect RCT, it was affected by BMI, MR grade, the RCT-presenting segments, and the etiology of MR.     

Plasma GRP-like immunoreactivity in healthy and diseased subjects

Gastrin releasing peptide(GRP)-like immunoreactivity in human plasma was measured using radioimmunoassay of neuromedin C (NMC) in 83 healthy and 58 diseased subjects. In the healthy group, the mean value of fasting GRP-like immunoreactivity was 2.1±1.4 (mean±SD) pmol/L. There was a slight positive correlation between the GRP-like immunoreactivity values and aging. Postprandial serial measurements demonstrated that GRP-like immunoreacitivity showed no response to a significant elevation of serum gastrin concentration. The group with chronic renal failure on hemodialysis gave the highest value, 7.1+2.1 pmol/L (p<0.01). There were no statistical differences between the healthy controls and groups with peptic ulcer, liver cirrhosis, diabetes mellitus or carcinomas, although some cancer patients had a marked increase in GRP-like immunoreactivity value.     

Impact of preoperative serum sodium concentration in living donor liver transplantation

Background and Aims: The importance of hyponatremia in deceased donor liver transplantation (DDLT) has been recently discussed frequently. However, its impact on the outcomes in living donor liver transplantation (LDLT) has not yet been elucidated. The current study was designed to demonstrate the impact of pre‐transplant sodium concentration on postoperative clinical outcomes. Methods: One hundred and thirty‐four patients who underwent LDLT for end‐stage liver diseases were examined to evaluate the significance of pre‐transplant hyponatremia (Na ≤ 130 mEq/L) on the short‐term clinical outcomes and the efficacy of the Model for End‐Stage Liver Disease and serum sodium (MELD‐Na) score using the sodium concentration and original MELD score. Results: The preoperative sodium and MELD score for all patients were 133.9 mEq/L (range: 109–142) and 16.2 (range: 6–38), respectively. According to a multivariate analysis, not only the MELD score (P = 0.030) but also the sodium concentration (P = 0.005) were found to be significant predictive factors for short‐term graft survival. Preoperative hyponatremia was a significant risk factor for the occurrence of sepsis (P < 0.001), renal dysfunction (P < 0.001) and encephalopathy (P = 0.026). The MELD‐Na score was 19.6 (range: 6–51) and the area under the receiver–operator curve of that (c‐statistics: 0.867) was higher than MELD score and sodium concentration (c‐statistics: 0.820 and 0.842, respectively). Conclusion: Preoperative hyponatremia was a significant risk for postoperative complications and short‐term graft loss. The addition of sodium concentration to MELD score might therefore be an effective predictor for post‐transplant short‐term mortality in LDLT.