Plantaricin LP84, a broad spectrum heat-stable bacteriocin of Lactobacillus plantarum NCIM 2084 produced in a simple glucose broth medium

Lactobacillus plantarum NCIM 2084 produced an antibacterial substance when grown at 40 degrees C for 36 h in a laboratory medium. The antibacterial substance was active against a wide range of bacteria comprising Gram positive and negative foodborne pathogenic and spoilage bacteria. However, related mesophilic lactobacilli were not inhibited, except for L. amylovorus DSM 20531. The antimicrobial activity was observed between late log and stationary growth phases. The antibacterial substance was partially purified through concentration under vacuum, followed by extraction with methanol and acetone (M-A extract). On fractionation of the M-A extract through Sephadex G-25, the activity was present in an eluant volume of 85 to 100 ml (peak I), indicating an apparent molecular mass of between 1 and 5 kDa and the purification attained was 80-fold. The antimicrobial principle was stable to heat (121 degrees C for 20 min) and catalase, but sensitive to trypsin and chymotrypsin, indicating it to be a bacteriocin. The M-A extract exhibited a bactericidal and lytic effect against Bacillus cereus F 4810 and Escherichia coli D 21. The ability of L. plantarum NCIM 2084 to produce an effective bacteriocin in a simple growth medium is of potential interest in its application as a biopreservative in traditional fermented foods.

Sunao Tawara: a father of modern cardiology

Knowledge of the conduction system of the heart was greatly advanced by Tawara's work carried out in Aschoff's laboratory in Marburg at the beginning of this century. In his monograph, The Conduction System of the Mammalian Heart, published in 1906, Tawara indicated that the treelike structure of specific muscle fibers comprising the atrioventricular node, His bundle, bundle branches, and Purkinje fibers served as the pathway for atrioventricular conduction of excitation in the mammalian heart. From his own anatomic and histological findings of the conduction system, he assumed precisely that the conduction velocity of excitation in the system, except in the atrioventricular node, would be fast and that contraction as the result of excitation would take place at the various sites of the ventricles almost simultaneously. According to Tawara, a long pathway to each contracting unit and a fast conduction velocity of excitation would be a prerequisite for the effective contraction of the ventricles. Tawara's findings and assumptions provided Einthoven the theoretical basis for interpreting the electrocardiogram, resulting in rapid popularization of electrocardiography. This century has witnessed the rapid progress of cardiology, including cardiac pacing and its related sciences. This progress has its roots in the discovery of the conduction system and the development of electrocardiography that took place almost in the same period at the beginning of this century. Tawara's pioneering work on the conduction system still serves as an invaluable reference for basic and clinical research.

Monomer Modifications of Denture Base Acrylic Resin: A Systematic Review and Meta-analysis

BACKGROUND

Methyl methacrylate monomer of denture base resins was modified with several monomers to achieve better physico-mechanical properties without compromising the biocompatibility. However, there are no consensuses on the best strategy to achieve best modified monomer.

PURPOSE

To identify and evaluate the differences in the properties between conventional and modified monomers and to verify the influence of several variables on the properties of denture base acrylic resin.

MATERIALS AND METHODS

This study was executed by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. In-vitro studies that investigated the properties of conventional and modified monomers were selected. Searches were carried out in the Ebscohost, PubMed, Semantic scholar and J-stage databases. The search commenced from the year 1995 and the last search was done till November 2018. A comparison was performed between modified and unmodified monomers. The analyses were carried out using fixed-effect models.

RESULTS

The meta-analysis results showed high heterogeneity in all aspects, and higher flexural strength for monomers modified with 20% methacrylic acid.

CONCLUSION

Although the articles included in this meta-analysis showed high heterogeneity and high risk of bias, the in-vitro literature seems to suggest that use of modified monomers could improve the properties of denture base resins. Other variants of monomer modifications and their tested parameters were discussed in this systematic review as well. Dimensional accuracy is an unexplored variable to be evaluated extensively in the future researches.

Changes in diastolic regional stiffness of the left ventricle before and after coronary artery bypass grafting

To evaluate the effect of coronary artery bypass grafting (CABG) on regional diastolic function of the left ventricular wall, we applied the concept of the stiffness constant to the diastolic sigma-ln (1/H) relation, where sigma is the mean wall stress, and H is the wall thickness of the region of concern, and ln (1/H) is the natural logarithm of the reciprocal of wall thickness. We assessed 12 cardiac regions in six patients with coronary artery disease who underwent CABG at the Cardiovascular Hospital of Central Japan between May 1994 and January 1995. Left ventricular pressure and regional wall thickness were measured simultaneously, with a micromanometer-tipped catheter and by two-dimensional echocardiography, respectively, before and after CABG. The stiffness constant (K) was obtained by fitting the diastolic sigma-ln (1/H) data points to an exponential curve with zero asymptote: sigma = Cexp[Kln (1/H)]. Preoperatively, the stiffness constant in the affected region (CABG region) was greater than that in the unaffected region (non-CABG region) (4.79 +/- 2.56 vs 2.95 +/- 0.72). Postoperatively, the stiffness constant in the CABG region was significantly decreased, to 3.21 +/- 1.22. The stiffness constant, which is derived from the sigma-ln (1/H) relation, is useful for the assessment of LV regional diastolic function.

Clinical performance of microporous polypropylene hollow-fiber oxygenator

A newly developed polypropylene hollow-fiber oxygenator was used from June 1979, to July, 1980, in 100 patients undergoing open-heart operation. Adequate oxygenation and carbon dioxide elimination were observed throughout perfusion in spite of a relatively low ratio of oxygen flow to blood flow. Plasma hemoglobin level was maintained low after long hours of perfusion. There were no complications related to the oxygenator during or after the operation. Because of its highly efficient performance as well as small size and easy handling, this oxygenator is being used routinely during open-heart procedures in our hospital.

Effect of Surface Modifications on the Retention of Cement-retained Implant Crowns under Fatigue Loads: An In vitro Study

Background:

Masticatory forces cause fatigue to the dental luting agents, adversely affecting the retention of these cement-retained crowns. Sandblasting (SB) and diamond abrading the abutment surface improves the bond strength of luting agents. However, the effect of acid etching (AE) on the implant abutment surface and the effect of other surface modifications under masticatory load are yet to be documented.

Purpose:

The aim of the study was to evaluate the effect of abutment surface modifications on the retention of cement-retained restorations subjected to cyclic fatigue loads.

Materials and Methods:

Forty Ni-Cr copings were made on Cp-titanium laboratory analogs. The specimens were divided into two groups as Group I: Uniaxial tensile loading (UTL) and Group II: Offaxial cyclic loading followed by uniaxial tensile loading [CTL]. Further subgrouped as, subgroup I: Control (C), subgroup II: SB, subgroup III: AE, and subgroup IV: SB + AE. The copings were luted with Zn₂(PO₄)₃ and subjected to uniaxial tensile loading. Copings were recemented, and CTL was conducted. Two-way analysis of variance was used as the statistical test of significance.

Results:

In relation to the subgroups, the bond strength of Zn₂(PO₄)₃ was higher in Group I than in Group II. The bond strength in subgroup IV was superior in both Group I and Group II (547.170 N ± 5.752 and 531.975 N ± 6.221 respectively).

Conclusions:

For both UTL and CTL, abutment SB + AE elicited maximum coping retention followed by AE. Off-axial cyclic loading adversely affected the retention irrespective of the surface modifications.

Cardiac surgery of eight children with Kawasaki disease (mucocutaneous lymph node syndrome)

The coronary arterial lesions of Kawasaki disease are characterized by multiple stenoses and aneurysms, which might lead to myocardial ischemia, myocardial infarction, mitral insufficiency due to ischemic papillary muscle dysfunction, ventricular aneurysm, etc. Eight children aged 6 to 13 years with Kawasaki disease underwent surgical treatments. These were coronary bypass surgery, coronary bypass surgery combined with right coronary aneurysmectomy and coronary bypass surgery combined with left ventricular aneurysmectomy. The postoperative course was smooth in all the patients. The selective angiography performed 1 month after the operation revealed the patency rate of 85% of the bypass grafts. However, 1 patient died suddenly during strenuous exercise 3 years after the surgery. Several points to be considered in the aortocoronary bypass in the patients with Kawasaki disease are discussed. These include the unknown fate of saphenous vein grafts and the possibility of higher incidences of graft failure in the growing children. Since the long-term postoperative results are as yet not fully understood, close follow-up of the patients treated by aortocoronary bypass surgery would be mandatory.

A percutaneously accessible pulsatile left ventricular assist device: modified assist device type 5

To provide percutaneous access, a new circulatory assist system was developed. We call this newly developed system the modified assist device (MAD). The system is composed of a sac-type blood pump and cannula. Inflow and outflow valves are mounted in the apex and at the side wall 10 cm from the apex of the cannula, respectively. During systole, the blood is sucked from the left ventricle through the inflow valve of the cannula connected to the blood pump, and during diastole, the blood is ejected to the root of the aorta through the outflow valve. In vitro and in vivo evaluations of the pump performance were performed. The maximum flow rate of 1.9 L/min was obtained in the mock circulatory system. In our animal experiment, effective systolic unloading and diastolic augmentation were observed by activation of this system during regular sinus rhythm. In conclusion, the MAD-5 is thought to be percutaneously accessible and increases systemic and coronary flow.

Postoperative deep body temperature rhythm

The postoperative deep body temperature rhythms of fifteen patients who received aorto-coronary bypass surgery (group I), and of seven patients who received non-cardiac major surgery (group II), were studied. Postoperative patients, especially those who received aortocoronary bypass surgery, showed greatly disturbed deep body temperature rhythm. There existed infradian and ultradian rhythm in both groups, and there existed two patients in group I who did not show sinusoidal rhythm. The patients of group I also showed a longer period of rhythm than did those of group II. The mesor and amplitude of the patients in group I showed a greater individual variation than did those in group II. The acrophase of both groups deviated widely. The patients who underwent cardiac surgery needed a longer time for temperature rhythm recovery than did those who underwent general surgery.

[Coronary artery bypass surgery in a patient with Basedow's disease controlled in hypothyroid state]

Coronary artery bypass surgery was performed in 55-year-old male with angina pectoris and Basedow's disease. His thyroid function was controlled in hypothyroid state, in order to avoid thyroid crisis perioperatively. At the start of the extra-corporeal circulation (ECC), values of T4, free-T4, T3 and free-T3 decreased progressively below the lower limits and remained depressed during ECC. The values returned almost to the pre-ECC levels at 2 hours after ECC. However, thereafter a gradual fall was seen up to 3 days after ECC. On the other hand, postoperative concentration of reverse-T3 progressively increased. Perioperative course was uneventful. The patient remains free of angina pectoris with optimal anti-thyroid drug therapy.