X-autosome and X-Y Translocations in Female Carriers: X-chromosome Inactivation Easily Detectable by 5-ethynyl-2-deoxyuridine (EdU).

Here we report one new case each of an X-autosome translocation (maternally derived), and an X-Y-chromosome translocation. Besides characterizing the involved breakpoints and/or imbalances in detail by molecular cyto-genetics, also skewed X-chromosome inactivation was determined on single cell level using 5-ethynyl-2-deoxyuridine (EdU). Thus, we confirmed that the recently suggested EdU approach can be simply adapted for routine diagnostic use. The latter is important, as only by knowing the real pattern of the skewed X-chromosome inactivation, correct interpretation of obtained results and subsequent reliable genetic counseling, can be done.

Computer-based three-dimensional visualization of developmental gene expression.

A broad understanding of the relationship between gene activation, pattern formation and morphogenesis will require adequate tools for three-dimensional and, perhaps four-dimensional, representation and analysis of molecular developmental processes. We present a novel, computer-based method for the 3D visualization of embryonic gene expression and morphological structures from serial sections. The information from these automatically aligned 3D reconstructions exceeds that from single-section and whole-mount visualizations of in situ hybridizations. In addition, these 3D models of gene-expression patterns can become a central component of a future developmental database designed for the collection and presentation of digitized, morphological and gene-expression data. This work is accompanied by a web site (http://www.univie.ac.at/GeneEMAC).

The usefulness of high pre-operative levels of serum type I collagen bone markers for the prediction of changes in bone mineral density after parathyroidectomy.

BACKGROUND: Amino-terminal procollagen propeptide of type I collagen (P1NP) and cross-linked C-terminal telopeptide of type I collagen (ßCTX) are two of the more sensitive bone markers for reflecting and monitoring patients with an increased bone turnover as observed in primary hyperparathyroidism (PHPT) patients. AIM: The present study was performed to evaluate the trend of type I collagen markers one year after parathyroidectomy (PTX) and to examine the relationships between serum P1NP and ßCTX levels and bone mineral density (BMD) change after PTX in PHPT Spanish patients. MATERIALS AND METHODS: Fifty-three PHPT patients were enroled and were followed for one year by measuring lumbar BMD, lumbar t-score, lumbar z-score, PTH, calcium, phosphorus, P1NP and ßCTX. RESULTS: Pre-surgery concentrations of both markers were elevated (P1NP: 90.71±5.03; ßCTX: 1.52±0.44). A significant decrease was observed in mean post-operative ßCTX and P1NP concentrations (p<0.0001). Levels of BMD, t-score and z-score at lumbar spine were relatively low (BMD: 0.75±0.16; z-score -0.90±0.23; t-score -2.51±0.32); after PTX a significant increase was observed in the levels of these three parameters. P1NP and ßCTX were correlated with lumbar BMD change one year after PTX (P1NP: r=0.79, p=0.016; ßCTX: r=0.89, p=0.003). CONCLUSIONS: Pre-surgery concentrations of both bone markers were elevated and a significant decrease after PTX was found. Serum ßCTX and P1NP levels were potently related to lumbar BMD changes over one year after PTX. The measurement of ßCTX and P1NP would be useful to predict long-term changes in lumbar BMD after PTX.

Impact of Histological Factors of Hepatocellular Carcinoma on the Outcome of Liver Transplantation.

BACKGROUND: The aim of this study was to identify predictors of overall survival (OS), disease-free survival (DFS), and recurrence in a cohort of 151 patients with hepatocellular carcinoma (HCC) and cirrhosis who were treated by liver transplantation (LT). PATIENTS AND METHODS: A retrospective database of patients undergoing LT for radiologically diagnosed HCC at "12 de Octubre" Hospital, Madrid during 1986-2006 was analyzed. RESULTS: The median follow-up was 67.44 months (SD = 55.7 months). Overall 1-, 3-, 5-, and 10-year survival was 87.5%, 73.7%, 64.1% and 43.4%, respectively. The 5-year OS of patients beyond the Milan criteria was 47.14%, whereas that of patients within the Milan criteria was 70.13% (P = .011). The 5-year OS of patients beyond the Milan criteria and with microvascular invasion (MVI) was 27.27%, whereas that of patients beyond the Milan criteria and without MVI criteria was 57.89% (P = .003). Multivariate analysis of prognostic factors revealed MVI and G3 to be independent and statistically significant factors affecting OS (P < .0001 and P = .045, respectively), DFS (P < .0001 and P = .004, respectively), and recurrence (P = .0002 and P = .028, respectively). Multivariate analysis of prognostic factors also revealed preoperative fine-needle aspiration (FNA) to be an independent negative statistically significant factor affecting recurrence (P = .0022). Multivariate analysis of predictive MVI factors revealed preoperative α-fetoprotein (AFP) levels >200 ng/mL to be an independent positive and statistically significant predictor of MVI (P = .0004). CONCLUSION: MVI and G3 are independent negative factors affecting OS, DFS, and recurrence. The presence of MVI or AFP levels >200 ng/mL represent a contraindication for LT, as long as the patient is beyond the Milan criteria.

Umbilical paracentesis for incarcerated umbilical hernia in patients with end-stage liver disease.

PURPOSE: Patients with cirrhosis and ascites are prone to abdominal wall complications largely predominate by umbilical hernia. Elective surgery is indicated in select patients but a high morbidity and mortality rate occurs if it is performed in emergency conditions. METHODS: We present a clinical case of a patient with advanced alcoholic liver disease who came to the emergency room for an acutely incarcerated umbilical hernia. Due to the high surgical risk, we had to discuss other treatment options. RESULTS: The use of umbilical paracentesis for incarcerated hernia reduction in cirrhotic patients with tense ascites is a safe and reproducible technique. CONCLUSIONS: Umbilical paracentesis could be considered as an alternative to emergency surgery in these high-risk patients.

[Listeria endophthalmitis]. / Listerien-Endophthalmitis.

Listeria monocytogenes is a rare cause of endogenous endophthalmitis. During the last 20 years about 30 cases have been published, all of which showed similar clinical features and a profound visual loss mainly owing to delayed diagnosis. This case report is about an otherwise healthy 41-year-old woman whose diagnosis was established 17 days after the onset of symptoms by microbiological cultures. Under sufficient therapy signs of local inflammation disappeared and intraocular pressure decreased. Pars plana vitrectomy was necessary; although post-surgery complications developed, the result was complete recovery of visual acuity.

Predictors of Obstructive Sleep Apnea Risk among Blacks with Metabolic Syndrome.

INTRODUCTION: Identification of risk factors for obstructive sleep apnea (OSA) is important to enable comprehensive intervention to reduce OSA-related cardiovascular disease (CVD). The metabolic syndrome outcome study (MetSO) provides a unique opportunity to address these factors. This study investigated risk of OSA among blacks with metabolic syndrome. METHODS: The present study utilized data from MetSO, an NIH-funded cohort study of blacks with metabolic syndrome. A total of 1,035 patients provided data for the analysis. These included sociodemographic factors, health risks, and medical history. Physician-diagnosed conditions were obtained using an electronic medical record system (Allscripts, Sunrise Enterprise). Patients were diagnosed with metabolic syndrome using criteria articulated in the joint interim statement for harmonizing the metabolic syndrome. Patients with a score ≥6 on the Apnea Risk Evaluation System (ARES) questionnaire were considered at risk for OSA. Obesity is defined by body mass index (BMI ≥ 30 kg/m2). RESULTS: Of the 1,035 patients screened in the MetSO cohort, 48.9% were at high risk for OSA. Using multivariate-adjusted logistic regression analysis, we observed that obesity was the strongest predictor of OSA risk (OR=1.59, 95%CI=1.24-2.04, p<0.0001). This finding remained significant even after adjustment for known covariates including blood pressure, low-density lipoprotein, high-density lipoprotein, and glucose levels (OR=1.44, 95%CI=1.11-1.86, p<0.001). CONCLUSION: Blacks in the MetSO cohort are at greater OSA risk, relative to the adult population in developed countries. Consistent with previous observations, obesity proved the strongest independent predictor of OSA risk among blacks with metabolic syndrome.

METABOLIC EFFECTS OF MARIJUANA USE AMONG BLACKS.

BACKGROUND: Increased legalization of marijuana has resulted in renewed interest in its effects on body weight and cardiometabolic risk. Conflicting data exist regarding marijuana effects on body weight, waist circumference as well as lipid profiles, blood pressure and cardiovascular disease. Furthermore, there is a dearth of data available on this effect in the black population. OBJECTIVE: To assess the metabolic profile and cardiovascular risk factors as well as body weight and waist circumference among urban black marijuana users. METHODS: A cross sectional study design involving 100 patients seen in a Family Practice clinic at University hospital of Brooklyn, NY, USA, over a period of 3 months from January 2014 to March 2014. Participants were administered a questionnaire regarding marijuana use, and other associated behaviors. Socio-demographic, laboratory, and clinical data were collected. We report measures of central tendencies, and dispersion for continuous variables and the frequency of distribution for categorical variables. RESULTS: Of the 100 patients surveyed, 57% were females. The mean (±SEM) age of the entire cohort was 46.3 years±1.5; range, 19-78 years. The mean body mass index (BMI) was 29.6 kg/m2±0.73; SBP=128.0 mmHg±1.69; DBP=76.1 mmHg±1.17. Current marijuana users had the lowest waist circumference compared to former or never users respectively (32.9±0.66 vs. 35.9±0.88 vs. 33.4±0.74), p<0.01. Diastolic blood pressure in mmHg was significantly higher among former marijuana users compared to current or never users, (80.0±2.1 vs. 73.3±2.3 vs. 73.4±1.6), p<0.01. Current marijuana users showed a tendency (not statistically significant) towards lower total cholesterol, Triglycerides (TG), High Density Lipoprotein (HDL)-cholesterol, Low Density Lipoprotein (LDL)-cholesterol, body mass index (BMI) and systolic blood pressure, compared to former users or never users. CONCLUSION: Current marijuana use is associated with significantly lower waist circumference, compared to former users and never users. Except for diastolic BP that was significantly lower among current users, other metabolic parameters showed tendency towards favorable profile. Further studies are needed to characterize the metabolic effects and to elucidate mechanisms of actions of marijuana in view of its rapid rate of utilization in the USA and around the world.

Riluzole series. Synthesis and in vivo "antiglutamate" activity of 6-substituted-2-benzothiazolamines and 3-substituted-2-imino-benzothiazolines.

Two series of analogues of riluzole, a blocker of excitatory amino acid mediated neurotransmission, have been synthesized: monosubstituted 2-benzothiazolamines and 3-substituted derivatives. Of all the compounds prepared in the first series, only 2-benzothiazolamines bearing alkyl, polyfluoroalkyl, or polyfluoroalkoxy substituents in the 6-position showed potent anticonvulsant activity against administration of glutamic acid in rats. The most active compounds displaying in vivo "antiglutamate" activity were the 6-OCF(3) (riluzole), 6-OCF(2)CF(3), 6-CF(3), and 6-CF(2)CF(3) substituted derivatives with ED(50) values between 2.5 and 3.2 mg/kg i.p. Among the second series of variously substituted benzothiazolines, compounds as active as riluzole or up to 3 times more potent were identified in two series: benzothiazolines bearing a beta-dialkylaminoethyl moiety and compounds with an alkylthioalkyl chain and their corresponding sulfoxides and sulfones. The most potent derivatives were 2-imino-3-(2-methylthio)- and 2-imino-3-(2-methylsulfinyl)-ethyl-6-trifluoromethoxybenzothiazolines (61 and 64, ED(50) = 1.0 and 1.1 mg/kg i.p., respectively). In addition, intraperitoneal administration of some of the best benzothiazolines protected mice from mortality produced by hypobaric hypoxia.

[Acute intravascular hemolysis after complete occlusion of a patent ductus arteriosus by detachable coils]. / Hémolyse intravasculaire aiguë après occlusion complète d'un canal artériel par coils détachables.

A case of acute intravascular haemolysis after complete occlusion of a patent ductus arteriosus by detachable coils in a 10 months old child is reported. The child had a patent ductus arteriosus, a small secundum atrial defect, mild valvular pulmonary stenosis, and stenosis of branches of the pulmonary artery not diagnosed before closure of the ductus. Haemolysis developed several hours after complete occlusion of the ductus by two detachable coils. The mechanism of the haemolysis was thought to be the presence of metallic spirals in the left pulmonary artery, just beyond stenosis situated at the origin of this artery. Simple balloon dilatation of the left pulmonary artery stenosis resulted in the complete regression of haemolysis.

[Patent ductal arteriosus occlusion by Rashkind umbrella and by detachable coil]. / Occlusion du canal artériel par ombrelle de Rashkind et par coil détachable.

UNLABELLED: The objective of this study is to report all of our experience of patent ductus arteriosus closure by interventional catheterisation, comparing two systems used successively: Rashkind umbrella and detachable coil. METHOD: Between January 1991 and July 2001, 72 patients underwent cardiac catheterisation in order to occlude patent ductus arteriosus (PDA). In 3 patients closure was not attempted (n = 1) or aborted (n = 2). The 69 patients in whom one or several prostheses were implanted are the object of this retrospective study. The patients were between 10 months and 18 years old (median 4 years), weighing between 6.7 and 54 kg (median 17 kg). The narrowest average angiographic diameter of the PDA was 2.2 mm (1 to 4 mm), type A in the Krichenko classification in 59 cases. The PDA was occluded by an umbrella in 29 patients (group 1), and from 1997 coils were used in 40 patients (group II). The medium term results were evaluated clinically and by colour doppler echocardiography. RESULTS: The age, weight, size and type of PDA were similar in the 2 groups. Group 1: 28 patients were treated with a single umbrella and one patient received 2 umbrellas. Systemic embolisation occurred in one case. The average period of follow-up was from 4 years to 10 years (average 6.5 years). The rate of residual shunt at 24 h, 6 months, and 12 months was 43%, 43%, and 39% respectively. A second implant was necessary in 2 children after 7 months and 30 months. The spontaneous disappearance of residual shunt was observed in 8 patients after between 1 month and 54 months (average 33.5 months). A slight residual shunt persisted in 4 patients (13.7%), 4.5 to 8.5 years after placing one or two umbrellas. The patients with a residual shunt were younger: 37 months versus 73 months (p < 0.05). Group II: 34 patients received a single coil and 6 patients several coils. Two cases of embolic migration and two cases of haemolysis were observed. The follow-up extended from 4 months to 4.5 years (average 2.2 years). The rate of residual shunt at 24 h, 6 months, and 1 year respectively was 35%, 10.5%, and 3.3%. At 6 and 12 months this rate was significantly less in group I (p < 0.01). Implantation of supplementary coils was necessary in 2 children at 24 h and at 9 months. Spontaneous disappearance of residual shunt occurred in 10 children out of 14 with an average interval of 5.5 months. A weak residual shunt remained detectable in 2 patients (5%) at 6 months and 36 months. CONCLUSION: The rate of initial residual shunt is comparable using both techniques. Spontaneous disappearance of residual shunts was observed in the majority of cases, but with the detachable coils this outcome is faster and the final rate for residual shunt is very low.

[Secondary displacement of an Amplatz occluder for atrial septal defect. 2 case reports]. / Déplacement secondaire d'une prothèse d'Amplatz de communication interauriculaire. A propos de 2 cas.

The authors report two cases of secondary displacement of an Amplatz occluder of isolated ostium secundum atrial septal defects. The displacement was observed at 1 month and the prosthesis removed at 3 months. To the best of the authors' knowledge, these are the first two reported cases of secondary displacement of this type of device. The main risk factor in the two cases was the absence of a subaortic septal remnant observed at surgical removal. This anatomical characteristic can be identified by transoesophageal echocardiography, but was poorly assessed by transthoracic echocardiography. Three-dimensional transoesophageal echocardiography should improve selection of atrial septal defects suitable for percutaneous treatment by better identification of their form and anatomical characteristics.

[Study of correlations between antibiotics prescriptions and guidelines in a neonatal intensive care unit]. / Etude de la corrélation entre les prescriptions d'antibiotiques et les recommandations dans une unité de soins intensifs néonatals.

UNLABELLED: The increasing use of wide spectrum antibiotics has been reported to be associated with a greater prevalence of multi-resistant bacteria. OBJECTIVES: The aims of this study were to survey the use of antibiotics and to evaluate the correlations between patterns of prescription of antibiotics and prescription guidelines in a neonatal intensive care unit. MATERIAL AND METHODS: In this 6-month study, all newborns admitted to the NICU and treated with antibiotics were included. Data regarding criteria of antibiotic prescription, length of treatment, and criteria of withdrawing treatment were collected. The correlation between prescriptions and guidelines was evaluated a posteriori by a non-prescriber physician. One hundred and sixteen newborns were included, of whom nine had received antibiotics on more than one occasion. Mean gestational age was 33.5 weeks. In 82% of cases, the reason for hospitalisation was respiratory distress syndrome. RESULTS: Patients received systemic antibiotics for primary infection (78%), nosocomial infection (17%) and postsurgical prophylaxis (5%). Suspected foeto-maternal infections (SFMI) were the dominant features of primary infection (96%). In 49% of cases, suspected infection was not proven and justified withdrawal of treatment within 3 days. Sixty percent of nosocomial infections occurred in newborns with gestational ages of less than 28 weeks. Bacterial criteria were decision-making factors only in nosocomial infections. An absence of observance of guidelines occurred in 9% of treated newborns, and in most cases involved excessive length of treatment. CONCLUSION: These results show: (1) the majority of antibiotic prescriptions were for not proven SMFI; (2) a low rate of nosocomial infections; (3) the predominance of nosocomial infections in premature newborns; (4) less than 10% of non-observance of guidelines. It appears necessary to develop more precise guidelines to limit antibiotic use and to evaluate them regularly.

Linking sleep to hypertension: greater risk for blacks.

Background. Evidence suggests that insufficient sleep duration is associated with an increased likelihood for hypertension. Both short (<6 hours) and long (>8 hour) sleep durations as well as hypertension are more prevalent among blacks than among whites. This study examined associations between sleep duration and hypertension, considering differential effects of race and ethnicity among black and white Americans. Methods. Data came from a cross-sectional household interview with 25,352 Americans (age range: 18-85 years). Results. Both white and black short sleepers had a greater likelihood of reporting hypertension than those who reported sleeping 6 to 8 hours. Unadjusted logistic regression analysis exploring the race/ethnicity interactions between insufficient sleep and hypertension indicated that black short (<6 hours) and long (>8 hours) sleepers were more likely to report hypertension than their white counterparts (OR = 1.34 and 1.37, resp.; P < 0.01). Significant interactions of insufficient sleep with race/ethnicity were observed even after adjusting to effects of age, sex, income, education, body mass index, alcohol use, smoking, emotional distress, diabetes, coronary heart disease, and stroke. Conclusion. Results suggest that the race/ethnicity interaction is a significant mediator in the relationship between insufficient sleep and likelihood of having a diagnosis of hypertension.

[Benefits of continuous subcutaneous insulin infusion in children with type 1 diabetes mellitus]. / Bénéfices de l'insulinothérapie par pompe chez les enfants diabétiques de type 1.

BACKGROUND: The Diabetes Control and Complications Trial clearly demonstrated the benefits of blood glucose control, especially in children and adolescents, in the prevention of long-term complications of type 1 diabetes (T1D). This can be achieved with intensive insulin treatment with either multiple daily insulin injections (MDI) or continuous subcutaneous insulin infusion (CSII), also known as insulin pump. The aim of this study was to compare glycemic control of T1D children treated with either CSII or MDI. PATIENTS AND METHODS: Thirty-eight T1D children treated with CSII were compared to 38 children treated with MDI, matched for age, gender, and duration of diabetes. Collected data, including daily doses of insulin in IU/kg/d, HbA1c levels, body mass index expressed in standard deviation/age, number of severe hypoglycemia episodes and of admissions related to T1D expressed in events/patient/year, were retrospectively collected every 3 months. RESULTS: There was no difference between the 2 groups at baseline. During the 3 years of follow-up, patients treated with CSII had lower daily doses of insulin (0.78 ± 0.19 vs. 0.87 ± 0.22 IU/kg/d, p<0.05), significantly lower levels of HbA1c (7.5 ± 0.6 vs. 8.0 ± 1.3 %, p<0.05), and a decreased number of admissions related to T1D (0.07 ± 0.14 vs. 0.17 ± 0.22 events/patient/year, p<0.05) than children treated with MDI. In contrast, body mass index and number of severe hypoglycemic episodes did not differ between the two groups. No diabetic ketoacidosis episode was recorded in either group. CONCLUSION: The results from this study suggest that treatment with CSII provided better metabolic control than treatment with MDI, in spite of lower daily doses of insulin and without increasing acute complications, in children with T1D.

Resistant hypertension and obstructive sleep apnea in the primary-care setting.

We ascertained the prevalence of resistant hypertension (RH) among blacks and determined whether RH patients are at greater risk for obstructive sleep apnea (OSA) than hypertensives. Method. Data emanated from Metabolic Syndrome Outcome Study (MetSO), a study investigating metabolic syndrome among blacks in the primary-care setting. Sample of 200 patients (mean age = 63 ± 13 years; female = 61%) with a diagnosis of hypertension provided subjective and clinical data. RH was defined using the JNC 7and European Society guidelines. We assessed OSA risk using the Apnea Risk Evaluation System ARES), defining high risk as a total ARES score ≥6. Results. Overall, 26% met criteria for RH and 40% were at high OSA risk. Logistic regression analysis, adjusting for effects of age, gender, and medical co morbidities, showed that patients with RH were nearly 2.5 times more likely to be at high OSA risk, relative to those with hypertension (OR = 2.46, 95% CI: 1.03-5.88, P < .05). Conclusion. Our findings show that the prevalence of RH among blacks fell within the range of RH for the general hypertensive population (3-29%). However, patients with RH were at significantly greater risk of OSA compared to patients with hypertension.

Evaluation of preoperative high magnetic field motor functional MRI (3 Tesla) in glioma patients by navigated electrocortical stimulation and postoperative outcome.

OBJECTIVES: The validity of 3 Tesla motor functional magnetic resonance imaging (fMRI) in patients with gliomas involving the primary motor cortex was investigated by intraoperative navigated motor cortex stimulation (MCS). METHODS: Twenty two patients (10 males, 12 females, mean age 39 years, range 10-65 years) underwent preoperative fMRI studies, performing motor tasks including hand, foot, and mouth movements. A recently developed high field clinical fMRI technique was used to generate pre-surgical maps of functional high risk areas defining a motor focus. Motor foci were tested for validity by intraoperative motor cortex stimulation (MCS) employing image fusion and neuronavigation. Clinical outcome was assessed using the Modified Rankin Scale. RESULTS: FMRI motor foci were successfully detected in all patients preoperatively. In 17 of 22 patients (77.3%), a successful stimulation of the primary motor cortex was possible. All 17 correlated patients showed 100% agreement on MCS and fMRI motor focus within 10 mm. Technical problems during stimulation occurred in three patients (13.6%), no motor response was elicited in two (9.1%), and MCS induced seizures occurred in three (13.6%). Combined fMRI and MCS mapping results allowed large resections in 20 patients (91%) (gross total in nine (41%), subtotal in 11 (50%)) and biopsy in two patients (9%). Pathology revealed seven low grade and 15 high grade gliomas. Mild to moderate transient neurological deterioration occurred in six patients, and a severe hemiparesis in one. All patients recovered within 3 months (31.8% transient, 0% permanent morbidity). CONCLUSIONS: The validation of clinically optimised high magnetic field motor fMRI confirms high reliability as a preoperative and intraoperative adjunct in glioma patients selected for surgery within or adjacent to the motor cortex.

Ontogeny of cytosolic proteins capable of modulating sarcoplasmic reticulum calcium transport in heart muscle.

In a previous study we described the inhibitory action of a cytosolic protein fraction from heart muscle on ATP-dependent Ca2+ uptake by sarcoplasmic reticulum (SR); further, this inhibition was shown to be blocked by an inhibitor antagonist, also derived from the cytosol (Narayanan et al. Biochim Biophys Acta 735: 53-66, 1983). The present study investigated the ontogenetic expression of the activities of Ca2+ transport inhibitor and inhibitor antagonist in heart cytosol during fetal and postnatal development of the rat. The SR Ca2+ transport inhibitor activity was undetectable in the cytosol of fetal (15- or 20-days gestation) rat heart but was manifested in the cytosol as early as one day after birth and increased progressively thereafter to reach almost adult levels within the first two weeks of postnatal development. The activity of the SR Ca2+ transport inhibitor antagonist was barely detectable in the near-term (20 days gestation) fetus but increased substantially during early postnatal development, in parallel with the rise in activity of the inhibitor. The ontogenetic appearance and increase in the activities of the Ca2+ transport inhibitor and its antagonist correlated well with the concurrent appearance and increase in the amounts of two polypeptides of apparent molecular weights 43 kDa and 64 kDa, which we have tentatively identified as the inhibitor and inhibitor antagonist, respectively. The co-ordinated expression of both the inhibitor and inhibitor antagonist activities in the cytosol during the early postnatal period parallels the morphogenesis and functional maturation of SR in cardiac muscle suggesting likely involvement of these cytosolic proteins in the physiological regulation of SR function.