Defibrillation testing at the time of ICD insertion: an analysis from the Ontario ICD Registry.

BACKGROUND: increasingly, ICD implantation is performed without defibrillation testing (DT). OBJECTIVES: To determine the current frequency of DT, the risks associated with DT, and to understand how physicians select patients to have DT. METHODS: between January 2007 and July 2008, all patients in Ontario, Canada who received an ICD were enrolled in this prospective registry. RESULTS: a total of 2,173 patients were included; 58% had new ICD implants for primary prevention, 25% for secondary prevention, and 17% had pulse generator replacement. DT was carried out at the time of ICD implantation or predischarge in 65%, 67%, and 24% of primary, secondary, and replacement cases respectively (P = <0.0001). The multivariate predictors of a decision to conduct DT included: new ICD implant (OR = 13.9, P < 0.0001), dilated cardiomyopathy (OR = 1.8, P < 0.0001), amiodarone use (OR = 1.5, P = 0.004), and LVEF > 20% (OR = 1.3, P = 0.05). A history of atrial fibrillation (OR = 0.58, P = 0.0001) or oral anticoagulant use (OR = 0.75, P = 0.03) was associated with a lower likelihood of having DT. Age, gender, NYHA class, and history of stroke or TIA did not predict DT. Perioperative complications, including death, myocardial infarction, stroke, tamponade, pneumothorax, heart failure, infection, wound hematoma, and lead dislodgement, were similar among patients with (8.7%) and without (8.3%) DT (P = 0.7) CONCLUSIONS: DT is performed in two-thirds of new ICD implants but only one-quarter of ICD replacements. Physicians favored performance of DT in patients who are at lower risk of DT-related complications and in those receiving amiodarone. DT was not associated with an increased risk of perioperative complications.

An investigation of health behavior change in Vietnamese-born individuals living in Sydney, Australia.

OBJECTIVE: The purpose of this study was to look at rates of acculturation among Vietnamese immigrants, with particular emphasis on health behaviors. DESIGN: A volunteer sample was surveyed. SETTING/PARTICIPANTS: The participants were drawn from inner and western Sydney, Australia. Participants were asked for their perception of their English fluency as a measure of likely exposure to health promotion advertising and their food, social, exercise, drinking, and smoking habits. RESULTS: It was found that the longer the Vietnamese immigrants participants had lived in Australia, the less likely they were to smoke; in fact, the smoking rate of this population is as low as that of the Australian population as a whole. However the immigrants did not change their low rate of alcohol consumption. In addition, the Vietnamese who had lived longer in Australia significantly increased their daily exercise and started to eat more take-away foods. CONCLUSIONS: With respect to health promotion, these changes are mixed: smoking has decreased, but half the group had begun eating take-away foods; this factor, if combined with a lack of exercise, is likely to lead to obesity.

Maternal transmission of SIVsmm in rhesus macaques.

Fifteen SIV-infected rhesus monkeys delivered 13 livebirths and two stillbirths; one livebirth died at three days of age. While all infants were culture-negative for SIV at birth, nine had maternal antibodies that disappeared by six months of age. Three infants subsequently seroconverted and became virus positive at 9-15 months. Milk samples from all mothers were virus-negative at parturition but samples from four animals were virus-positive at nine and 12 months. This study documents maternal transmission of SIV and suggests transmission by breast-feeding.

Transmission of retroviral infection by transfusion of seronegative blood in nonhuman primates.

Techniques such as polyclonal B cell activation with pokeweed mitogen (PWM) and polymerase chain reaction (PCR) analysis have documented the existence of simian immunodeficiency virus (SIV)-and human immunodeficiency virus type 1-seronegative but infected humans and nonhuman primates. To establish whether blood from such seronegative but PWM- and PCR-positive monkeys can transmit infection, naive macaques were transfused with whole blood (n = 2) or cultured cells and supernatant fluid (n = 2) from two seronegative but PWM- and PCR-positive sooty mangabeys. After transfusion, three of the four recipients seroconverted, and peripheral blood mononuclear cells from all four recipients secreted SIV-reactive antibodies upon polyclonal activation in vitro and were SIV-positive by PCR that used highly specific gag primer pairs and probe. In addition, CD8+ cells from all four recipients markedly inhibited replication of SIV in autologous cells in vitro. These data suggest caution in the sole use of serologic tests for the detection of retroviral infection and document the ability of such blood samples to transmit infection.

Spectrum of disease in macaque monkeys chronically infected with SIV/SMM.

Twelve rhesus and one pig-tailed macaque have been monitored for 28-41 months following experimental infection with 10(4) TCID of SIV/SMM. Twelve of the 13 animals became virus positive and seroconverted within 3 to 6 weeks of exposure; the remaining animal seroconverted at 6 months, but has remained virus negative. Six of the 13 animals (46%) died between 14 and 28 months post-infection, following prolonged clinical disease characterized by chronic diarrhea and weight loss, peripheral lymphadenopathy and hemogram abnormalities. Histologic findings ranged from prominent follicular hyperplasia to severe lymphoid depletion, with lymphoid tissues often showing an infiltrate of syncytial giant cells. One animal had intestinal cryptosporidiosis and two had brain lesions comparable to those seen in AIDS encephalopathy in humans. Three of the remaining seven animals have an ARC-like disease and are showing gradual deterioration of their clinical condition. These animals, as well as animals that died, had progressive decreases in CD4+ cells and CD4+/CD8+ cell ratios. These observations further document the marked clinical, pathologic and immunologic similarities between human AIDS and the SIV-infected macaque model.

Synergistic inhibition of metabolic cooperation by oleic acid or 12-0-tetradecanoylphorbol-13-acetate and dichlorodiphenyltrichlorethane (DDT) in Chinese hamster V79 cells: implication of a role for protein kinase C in the regulation of gap junctional intercellular communication.

The effects of TPA and/or DDT and oleic acid and/or DDT on gap junction-mediated intercellular communication (i.e. metabolic cooperation) between Chinese hamster V79 cells was examined. Addition of TPA, DDT or oleic acid alone to cocultures of 6-thioguanine-resistant (6-TGR) and 6-thioguanine-sensitive (6-TGS) V79 cells significantly increased the recovery of 6-TGR cells indicating inhibition of metabolic cooperation. In the presence of TPA and DDT or oleic acid and DDT the observed recovery of 6-TGR cells was significantly greater than the expected (calculated) additive 6-TGR cell recovery. No synergistic increases in 6-TGR cell recovery were observed when co-cultures of V79 cells were exposed to dieldrin and DDT. These results indicate that TPA and DDT or oleic acid and DDT can act synergistically to inhibit metabolic cooperation. These data suggest a role for protein kinase C in the regulation of gap junction-mediated intercellular communication.

Genetic markers of immunoglobulins in the two orangutan subspecies and their hybrids.

Serum samples from 23 Pongo pygmaeus abelii, 4 Pongo pygmaeus pygmaeus and 2 hybrids were tested for Gm (1, 2, 3, 5, 6, 10, 11, 13, 14, 15, 16, 17, 21, 24, 28) and for Km (1) allotypes. All samples were negative for Gm (2, 3, 5, 6, 14, 16, 21, 28), Km (1) and positive for Gm (1, 15, 17, 24). The allotypes G3m (10, 11, 13) were simultaneously absent in all of the Bornean orangutans and present in all of the Sumatran orangutans. Moreover, the analysis of 8 Bm allotypes has shown that all the P. pygmaeus abelii and their hybrids only possess one Bm marker and that all the 4 P. pygmaeus pygmaeus are negative for all the antigens.

Steroid excretion and metabolism by gonadal tissue from a subject with testicular feminization syndrome.

The initial clinical, pathological, and hormonal investigation of a patient with testicular feminization syndrome is described. Incubation of gonadal tissue with various radioactive substrates, together with the isolation and identification of the resulting metabolites, was demonstrated a high capacity to synthesize testosterone. Two biosynthetic pathways were demonstrated, originating from progesterone and pregnenolone. These are essentially similar to those of the normal adult testes. Low levels of activity were found in the phenolic fractions and no measurable production of oestrone, oestradiol, or oestriol was found.

Abnormal excretion of corticosteroid sulphates in patients with breast cancer.

In a preliminary study, the 24-hour urinary excretion of corticosteroid sulphates and free cortisol have been measured in a group of patients with breast cancer and compared with the excretion of the same compounds in a group of normal women of similar age. Excretion of corticosteroid sulphates in the breast cancer group was found to be markedly raised. In a small number of patients with localized cancer of sites other than the breast the level of corticosteroid sulphate was not raised. If proved metastases were present a noticeable rise was observed.

The course of ketosis and the activity of key enzymes of ketogenesis and ketone-body utilization during development of the postnatal rat.

1. The highest blood concentrations of ketone bodies were found at 5 days of age, after which time the concentration fell to reach the adult value by 30 days of age. 2. Both mitochondrial and cytoplasmic hydroxymethylglutaryl-CoA synthase activities were detected, with highest activities being found in the mitochondria at all stages of development. Activity of the mitochondrial enzyme increases rapidly immediately after birth, showing a maximum at 15 days of age, thereafter falling to adult values. The cytoplasmic enzyme, on the other hand, increased steadily in activity after birth to reach a maximum at 40 days of age, after which time activity fell to adult values. 3. Both mitochondrial and cytoplasmic aceto-acetyl-CoA thiolase activities were detected, with the mitochondrial enzyme having considerably higher activities at all stages of development. The developmental patterns for both enzymes were very similar to those for the corresponding hydroxymethylglutaryl-CoA synthases. 4. The activity of heart acetoacetyl-CoA transferase remains constant from late foetal life until the end of the suckling period, after which time there is a gradual threefold increase in activity to reach the adult values. The activity of brain 3-oxo acid CoA-transferase increases steadily after birth, reaching a maximum at 30 days of age, thereafter decreasing to adult values, which are similar to foetal activities. Although at all stages of development the specific activity of the heart enzyme is higher than that of brain, the total enzymic capacity of the brain is higher than that of the heart during the suckling period.

Fatty acid utilization during development of the rat.

1. In the absence of added carnitine pronounced changes occur during development, in the degradation of [U-(14)C]palmitate to (14)C-labelled acid-soluble material (predominantly ketone bodies) and (14)CO(2) by liver homogenates. The formation of both products by liver homogenates of 5-day-old rats is considerably higher than in foetal livers. This high value is maintained during the suckling period and falls after weaning to adult values which are similar to those of the foetus. Addition of carnitine stimulates production of acid-soluble material throughout development. The effect of added carnitine on CO(2) production varies with age, stimulating in foetal and post-weaning age groups but inhibiting during the suckling period. 2. The degradation of [U-(14)C]palmitate to acid-soluble material and CO(2) by heart homogenates also varies during development. Formation of both products is highest 5 days after birth and thereafter decreases steadily to adult values. Addition of carnitine stimulates the production of both CO(2) and acid-soluble material at all ages. 3. The activity of carnitine palmitoyltransferase in liver increased after birth to reach maximum activity at 2-5 days of age. Thereafter the activity of the enzyme decreased until day 15 of life and then remained constant until day 30, decreasing after this time to adult values which were about one half of the foetal liver activities.

Factors involved in changes in hepatic lipogenesis during development of the rat.

1. Changes in the activities of acetyl-CoA carboxylase (EC 6.4.1.2), phosphofructokinase (EC 2.7.1.11), aldolase (EC 4.1.2.13), extramitochondrial aconitate hydratase (EC 4.2.1.3) and NADP-dependent isocitrate dehydrogenase (EC 1.1.1.42) have been measured in the livers of developing rats from late foetal life to maturity. 2. The effect of altering the weaning time on some enzymes associated with lipogenesis has been studied. Weaning rats at 15 days of age instead of 21 days results in an immediate increase in the activity of ;malic' enzyme (EC 1.1.1.40) whereas the activities of glucose 6-phosphate dehydrogenase (EC 1.1.1.49) and ATP citrate lyase (EC 4.1.3.8) did not increase until 4-5 days and acetyl-CoA carboxylase 2-3 days after early weaning. Weaning rats on to an artificial-milk diet led to complete repression of the rise in activity of hepatic enzymes associated with lipogenesis normally found on weaning, except for ;malic' enzyme, which increased in activity after 20 days of age. 3. The effect of intraperitoneal injections of glucagon, cortisol, growth hormone and thyroxine on the same hepatic enzymes has been investigated. Only thyroxine had any effect on enzyme activities and caused a 20-fold increase in ;malic' enzyme activity and a twofold increase in ATP citrate lyase activity. 4. The activities of hepatic glucose 6-phosphate dehydrogenase and ;malic' enzyme are higher in adult female than in adult male rats and it has been shown that this sex difference in enzyme activities is due to both male and female sex hormones. 5. Hepatic malate, citrate, pyruvate, glucose 6-phosphate and phosphoenolpyruvate concentrations have been measured throughout development. 6. The results are discussed in relation to the dietary and hormonal control of hepatic enzyme activities during development.