EFFECT OF PASTEURIZATION AND OF FREEZING AND THAWING HUMAN MILK ON ITS TRIGLYCERIDE CONTENT

ABSTRACT. Wardell, J. M., Hill, C. M. and D'Souza, S. W. (Department of Child Health, St. Mary's Hospital, Manchester, UK). Effect of pasteurization, and freezing and thawing human milk on its triglyceride content. Acta Paediatr Scand, 70:467,.–In a study of human milk collected for banking, heating at 62.5°C for 30 min, and freezing and thawing resulted in hydrolysis of triglycerides. Freezing and thawing caused disruption of fat globules and a greater hydrolysis of triglycerides than did the heating process. There was a decrease in the percentage of the poly-unsaturated fatty acids linoleic acid (C18:2) and linolenic acid (C18:3) after freezing and thawing, and after heating, but the other fatty acids of human milk triglycerides were not affected. It is suggested that the availability of linoleic and linolenic acid in milk declines when these procedures are used in human milk banking.     

Heart Volume and Myocardial Connective Tissue during Development and Regression of Thyroxine-Induced Cardiac Hypertrophy in Rats

To determine whether development and regression of cardiac hypertrophy are accompanied by changes in heart volume and to learn whether a change in heart volume is associated with changes in the myocardial connective tissue, cardiac hypertrophy was induced in rats by administration of thyroxine. Rats were given L-thyroxine for 4 weeks. Heart volume was estimated radiologically in vivo at the start of the experiment and at 1- or 2-week intervals for 7 weeks. At each of these stages a number of rats were killed, their hearts were weighed and determinations were made of the myocardial contents of DNA, of collagen measured as hydroxyproline, and of glycosaminoglycans, measured as uronic acid. After thyroxine treatment the ratio of left heart ventricle weight to body weight and of heart volume to body weight rose significantly. The increase in heart weight was greater than the increase in heart volume. At the same time, there was a significant decrease in the concentration of hydroxyproline. After discontinuation of thyroxine treatment heart volume, heart weight and the concentration of myocardial collagen returned to normal within 2 weeks. However, the total amount of myocardial collagen was still less than normal at 2 weeks. The results suggest that the decrease in the amount of myocardial collagen associated with thyroxine-induced cardiac hypertrophy—because it results in a weakening of the supporting properties of the myocardial connective tissue framework— might contribute to a slight increase in in vivo heart volume.     

REGIONAL DISTRIBUTION OF 11C-LABELED LIDOCAINE,BUPIVACAINE, AND ROPIVACAINE IN THE HEART,LUNGS, AND SKELETAL MUSCLE OF PIGS STUDIED WITH POSITRON EMISSION TOMOGRAPHY

The regional myocardial uptake and kinetics of ¹¹C-lidocaine, ¹¹C-bupivacaine, and ¹¹C-ropivacaine were examined in the pig, utilizing positron emission tomography to determine whether disproportionate distribution exists among these agents. The three drugs were rapidly distributed to the myocardium and lung with mean peak radioactivities occurring between 0·35 and 0·48 min post-injection in myocardium and 0·35 and 0·65 min in lung. Radioactivities peaked later in skeletal muscle than in the myocardium and lung, occurring between 1·1 and 2·7 min post-end injection. Blood radioactivities for bupivacaine and ropivacaine were significantly higher than those of lidocaine, whereas myocardial, lung, and muscle uptakes for the three agents were not significantly different. Myocardium–blood partition coefficients were similar for bupivacaine and ropivacaine (0·55 and 0·49 respectively), while it was three times higher for lidocaine (1·4). A similar relationship existed for skeletal muscle– and lung–blood partition coefficients. Bupivacaine and ropivacaine t_1/2z in skeletal muscle were significantly longer than those of lidocaine. The results of this study indicate that the increased cardiotoxicity associated with bupivacaine does not appear to be related to disproportionate distribution in the myocardium when compared to lidocaine and ropivacaine. © 1997 by John Wiley & Sons, Ltd.     

BCL-2 IMMUNOREACTIVITY INCREASES WITH SEVERITY OF CIN: A STUDY OF NORMAL CERVICAL EPITHELIA,CIN, AND CERVICAL CARCINOMA

The presence of the BCL-2 protein, a marker for inhibition of programmed cell death, was studied in a series of routinely processed cervical tissues, consisting of normal endocervical ( n =40) and ectocervical epithelium ( n =27), squamous metaplastic epithelium ( n =30), CIN (cervical intraepithelial neoplasia) lesions ( n =32), and cervical carcinomas ( n =13). BCL-2 was strongly expressed in the basal cell compartment of normal ectocervical squamous epithelium and in nearly all reserve cells, while in endocervical columnar cells it was moderately expressed. In immature squamous metaplastic epithelium, BCL-2 expression varied. Half of the cases showed only basal cell staining, while the other half showed staining also in suprabasal layers. BCL-2 could be detected in all premalignant lesions, showing a striking increase in the number of positive cells with increasing severity of CIN, in combination with a mild increase in staining intensity. All adenocarcinomas were positive ( n =5), while five of eight squamous cell carcinomas expressed BCL-2. Based on these results, it is hypothesized that both the larger number of cells staining with BCL-2 in higher grades of CIN and the increase in staining intensity imply an increasing protection of these neoplastic conditions against programmed cell death. This protection facilitates not only continuing proliferation, but also the induction of genetic instability in dysplastic epithelial cells; it may thus reflect the greater capacity of the more severe CIN lesions to evolve into cervical carcinoma.     

Transesophageal Echocardiography for Insertion of a Physiological Pacemaker in Early Pregnancy

A dual chamber pacemaker was implanted during the first trimester of pregnancy in a patient with second-degree heart block and syncope. Transesophageal echocardiography was used to confirm satisfactory position in the right atrial appendage.     

INTRANASAL LHRH AGONIST TREATMENT FOR INHIBITION OF OVULATION IN WOMEN: CLINICAL ASPECTS

Daily intranasal administration of the potent stimulatory LHRH analogue D-Ser(TBU)⁶-EA¹⁰-LHRH was given to fifty healthy women for 3 months. Twenty-six women received 400 μg LHRH agonist/day and twenty-four women received 600 μg/day. Inhibition of ovulation occurred during 147 of the 150 treatment months. The three presumptively ovulatory cycles were probably the result of initial technical problems with the nasal spray. No pregnancies occurred. Reactivation of corpus luteum with slightly raised progesterone levels in serum at initiation of treatment was observed in six women. During 20 months of treatment the serum progesterone levels were slightly raised, indicating luteinization of follicles or defect luteal phases. Most of the women had menstrual-like bleeding during treatment. Seventeen volunteers had regular bleeding and twenty-three women had oligomenorrhoea. No dysfunctional uterine bleeding occurred, but three women reported spotting. The remaining ten women had amenorrhoea during treatment without any symptoms of oestrogen deficiency. After discontinuation of treatment the women regained ovulatory menstrual cycles after 31 days on average. The treatment was very well accepted by all the women.     

Potential Causes of Spurious Programming: Report of a Case

The possibility of false or inadvertent reprogramming increases with the availability of different and more complex programming mechanisms. A case of spurious programming during application of the Vitatron MPA1 analyzer to a Medtronic impulse generator (IPG) is described and the nature of the phenomenon is explained. It is concluded that the introduction of a simple and standardized "security-maneuvre" to which every IPG will respond safely, in the event of fortuitous dysprogramming, is required.