Core outcome set for perinatal interventions for congenital diaphragmatic hernia

OBJECTIVE

To develop a core set of prenatal and neonatal outcomes for clinical studies evaluating perinatal interventions for congenital diaphragmatic hernia, using a validated consensus-building method.

METHODS

An international steering group comprising 13 leading maternal-fetal medicine specialists, neonatologists, pediatric surgeons, patient representatives, researchers and methodologists guided the development of this core outcome set. Potential outcomes were collected through a systematic review of the literature and entered into a two-round online Delphi survey. A call was made for stakeholders with experience of congenital diaphragmatic hernia to review the list and score outcomes based on their perceived relevance. Outcomes that fulfilled the consensus criteria defined a priori were discussed subsequently in online breakout meetings. Results were reviewed in a consensus meeting, during which the core outcome set was defined. Finally, the definitions, measurement methods and aspirational outcomes were defined in online and in-person definition meetings by a selection of 45 stakeholders.

RESULTS

Overall, 221 stakeholders participated in the Delphi survey and 198 completed both rounds. Fifty outcomes met the consensus criteria and were discussed and rescored by 78 stakeholders in the breakout meetings. During the consensus meeting, 93 stakeholders agreed eventually on eight outcomes, which constituted the core outcome set. Maternal and obstetric outcomes included maternal morbidity related to the intervention and gestational age at delivery. Fetal outcomes included intrauterine demise, interval between intervention and delivery and change in lung size in utero around the time of the intervention. Neonatal outcomes included neonatal mortality, pulmonary hypertension and use of extracorporeal membrane oxygenation. Definitions and measurement methods were formulated by 45 stakeholders, who also added three aspirational outcomes: duration of invasive ventilation, duration of oxygen supplementation and use of pulmonary vasodilators at discharge.

CONCLUSIONS

We developed with relevant stakeholders a core outcome set for studies evaluating perinatal interventions in congenital diaphragmatic hernia. Its implementation should facilitate the comparison and combination of trial results, enabling future research to better guide clinical practice. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Hyperammonaemia in Neonates and Young Children: Potential Metabolic Causes, Diagnostic Approaches and Clinical Consequences

Hyperammonaemia is a metabolic disturbance characterized by accumulation of ammonia in the blood. Entry of ammonia into the brain via the blood-brain barrier leads to hyperammonaemic encephalopathy. The causes of hyperammonaemia in paediatric patients vary. We present 3 cases of hyperammonaemia in critically ill children in whom an inborn metabolic disorder was identified and provide insights into the phenotypes, diagnostic approaches and management. In children with acute overwhelming illness and progressive neurological deterioration plasma ammonia measurement should be included in the urgent diagnostic work-up. We here raise the awareness that hyperammonaemia is a metabolic emergency requiring prompt recognition and treatment to avoid subsequent complications.

Assessing the Appropriateness of Oral Anticoagulation for Atrial Fibrillation in Advanced Frailty: Use of Stroke and Bleeding Risk-Prediction Models

BACKGROUND

Atrial fibrillation (AF) is common among frail older adults. Oral anticoagulation (OAC) is particularly challenging for these due to overlapping stroke and bleeding risk factor profiles.

OBJECTIVE

To compare the utility of stroke and haemorrhage risk-prediction instruments in the treatment of AF among frail older adults.

DESIGN

Cross-sectional study.

SETTINGS AND PARTICIPANTS

Frail residents in four nursing homes with a Clinical Frailty Scale score ≥5 (median 7±0).

MEASUREMENTS

The prevalence of AF was assessed by ECG and chart review. Stroke (CHADS2 and CHA2DS2-VASc) and bleeding (HASBLED and HEMORR2HAGES) risk-prediction scores were then applied. A validated, risk-based, colour-coded decision support tool, incorporating these instruments, was then used to create a risk matrix and assess the appropriateness of OAC.

RESULTS

In total, 225 patients were included. The distribution of CFS scores was similar irrespective of AF status. In all, 86/225 (38%) had any history of AF. Of these, only 15/86 (17%) were prescribed OAC. All those in AF scored ≥2 on the CHA2DS2-VASc. One-third also scored high-risk of bleeding using HAS-BLED or HEMORR2HAGES. Risk-prediction scores were similar between those with 'known' (documented) and occult (only on ECG) AF. The colour-coded decision tree suggested that OAC would be recommended for the majority in AF when HAS-BLED (60/86, 70%) was used as the bleeding risk-prediction instrument. Despite this, only 12/60 (20%) were anticoagulated. When HEMORR2HAGES was incorporated instead, one patient was advised OAC, the remainder no treatment (57%) or an antiplatelet (42%).

DISCUSSION

Stroke risk was high and bleeding risk levels comparatively low, suggesting that the balance of risk may favor OAC for AF in this cohort of patients with advanced frailty. Despite this and the high prevalence of AF, OAC prescription rates were low. The decision-support tool used showed mixed results, depending on the bleeding-risk score incorporated, suggesting that while useful, they should not replace clinical judgement.

A Comparison of Perceived and Measured Paternal Weight and BMI, and Relationship to Weight and BMI of his Children

INTRODUCTION

Nineteen percent of 9 years old Irish children are overweight; seven percent are obese. Our aims were: to examine whether differences exist between paternal self-reported and measured height, weight and BMI in a population representative sample; and to explore paternal perceptions of their own weight status.

METHODS

Measures of height and weight for fathers and for their children from the National Longitudinal Study of Children Growing Up in Ireland were obtained using validated methods.

RESULTS

Three quarters of fathers (6,263 of 8,568 study children) with a mean age of 42 years (SD 5.04) responded. The mean difference between self-reported and measured weight was -1.03kg (SD=4.52), indicating that weight was underestimated. Obese fathers were more likely to have an obese son (9.4% compared to 5.3% for the full cohort) and an obese daughter (12.4% compared to 7.7%).

DISCUSSION

These data suggest that there is a strong relationship between fathers' weights and his childrens' weights. A leading factor in the development of childhood obesity is parental obesity. Targeting overweight and obesity in the child should occur simultaneously with tackling overweight and obesity in the parents; in this study, the fathers.

Closing system-wide yield gaps to increase food production and mitigate GHGs among mixed crop-livestock smallholders in Sub-Saharan Africa

In this study we estimate yield gaps for mixed crop-livestock smallholder farmers in seven Sub-Saharan African sites covering six countries (Kenya, Tanzania, Uganda, Ethiopia, Senegal and Burkina Faso). We also assess their potential to increase food production and reduce the GHG emission intensity of their products, as a result of closing these yield gaps. We use stochastic frontier analysis to construct separate production frontiers for each site, based on 2012 survey data prepared by the International Livestock Research Institute for the Climate Change, Agriculture and Food Security program. Instead of relying on theoretically optimal yields-a common approach in yield gap assessments-our yield gaps are based on observed differences in technical efficiency among farms within each site. Sizeable yield gaps were estimated to be present in all of the sites. Expressed as potential percentage increases in outputs, the average site-based yield gaps ranged from 28 to 167% for livestock products and from 16 to 209% for crop products. The emission intensities of both livestock and crop products registered substantial falls as a consequence of closing yield gaps. The relationships between farm attributes and technical efficiency were also assessed to help inform policy makers about where best to target capacity building efforts. We found a strong and statistically significant relationship between market participation and performance across most sites. We also identified an efficiency dividend associated with the closer integration of crop and livestock enterprises. Overall, this study reveals that there are large yield gaps and that substantial benefits for food production and environmental performance are possible through closing these gaps, without the need for new technology.

Aunties and Uncles Co-operative Family Project: the experiences of children, volunteers and parents

BACKGROUND

This paper reports on the experiences of the children (nieces and nephews), volunteers (aunts and uncles) and parents involved in the Aunties and Uncles Co-operative Family Project in Sydney, Australia. The project has run for 30 years as an extended family network of community volunteers and has never been evaluated.

METHODS

A survey comprising open-ended and closed questions relating to the service was administered to all stakeholders. Demographic data were collected on all respondents. The text from answers to open-ended questions on the survey was coded for similarities and differences and was categorized. From the categories, the experiences of children, volunteers and parents were written with exemplars from the respondents' text.

RESULTS

Three major categories emerged from the text: enjoyment/satisfaction of the experience for volunteers, children and parents; family relationships; and the difference it has made to me (children, parents and volunteers).

CONCLUSIONS

The long-term benefits of a supportive 'extended family type' relationship were recognized by all participants. Although the children were the primary focus of the project, parents and volunteers also described the rewards they experienced. The volunteer element was integral to providing the wide-ranging, ongoing supports which would not be possible from a paid staff basis.

Guanidinoacetate methyltransferase deficiency masquerading as a mitochondrial encephalopathy

Guanidinoacetate methyltransferase (GAMT) deficiency is a rare disorder of creatine synthesis. We report a patient who presented at 10 months of age with hypotonia and global developmental delay. Subsequently, she developed seizures and choreoathetosis. Magnetic resonance imaging showed high signal bilaterally in the globus pallidus on T2-weighted images. Mitochondrial respiratory chain studies revealed low complex I activity (in muscle 0.052 nmol NADH oxidized per min per unit citrate synthase, controls 0.166 +/- 0.047; in fibroblasts 0.080 nmol NADH oxidized per min per unit citrate synthase, controls 0.197 +/- 0.034). The true diagnosis was suspected at 21 months of age because of persistent low plasma and urine creatinine concentrations. GAMT activity was undetectable in fibroblasts and compound heterozygous mutations were found in the GAMT gene (c.327G>A and c.522G>A). The patient was treated with creatine, dietary arginine restriction and ornithine supplements. Her movement disorder and seizures resolved but she still has severe cognitive impairment and no expressive language. The occurrence of secondary respiratory chain abnormalities in GAMT deficiency may lead to misdiagnosis, particularly as the clinical and radiological features resemble those seen in mitochondrial encephalopathies. It is important to establish the correct diagnosis because specific treatment is available.

Perception of the risks of smoking in the general population and among general practitioners in Ireland

BACKGROUND

Data on perception of smoking risk amongst the Irish population are sparse.

AIMS

To study the accuracy and determinants of the perceived risk of premature death due to smoking in the general population and amongst general practitioners (GPs).

METHODS

Telephone surveys of a representative sample of Irish adults (1,247) and GPs (171; 85% response rate) asked participants to estimate how many of 1,000 20-year-old life-long smokers would die from smoking-related disease before the age of 70 and to identify the main cause of death from a list of seven causes: smoking, road traffic accidents, accidents at work, AIDS, homicide, illicit drugs and alcohol misuse.

RESULTS

In the population and GP samples, perception of the risk of smoking-related death was similar (median 200 and 150 deaths per 1,000 smokers respectively, epidemiological estimates 250/1000). Only 43% of the population identified smoking as the most important cause of death compared with 87% of GPs. Current smoking status, younger age, female gender, lower educational attainment and lower income were associated with failure to identify smoking as the main cause of death.

CONCLUSION

Despite decades of health promotion, the general public underestimates the relative importance of smoking as a cause of death.

Canadian Cardiovascular Society Consensus Conference 2002: Management of heart disease in the elderly patient

Cardiovascular disease is a major health issue for the elderly patient. Many diagnostic, therapeutic and ethical issues are specific for the the older adult with heart disease. The Canadian Cardiovascular Society 2002 Consensus Conference provides recommendations for the most frequently encountered cardiac problems in the elderly patient. A common theme of the recommendations is the need to apply the best evidence based medicine together with an assessment of frailty, comorbidity and quality of life. A major goal of the conference was to identify treatments that are not optimally used in the older patient.

A case of Histoplasma capsulatum causing granulomatous liver disease and Addisonian crisis

A 56-year-old man with persistently elevated liver enzyme levels, fatigue, lethargy and a 9.0 kg weight loss over six months underwent a percutaneous liver biopsy that demonstrated multiple granulomas. Screening serologies were positive for histoplasmosis, and he was started on itraconazole treatment. He returned to hospital the same night with coffee-ground emesis and in Addisonian crisis requiring parenteral steroids and intensive care unit support. An abdominal computed tomography scan revealed bilaterally enlarged, nonenhancing adrenal glands suggestive of infarcts, presumed secondary to histoplasmosis. Treatment was initiated with amphotericin B, and Histoplasma capsulatum was cultured from his urine and cerebrospinal fluid. A serum immunodiffusion test was also positive for both H and M bands, indicating active infection with Histoplasmosis species. His serum and urine samples were also weakly positive for the antigen. Despite complications of renal failure, pneumonia and congestive heart failure, he recovered with medical therapy and was discharged home to complete a prolonged course of itraconazole therapy. While hepatic granulomas often reflect an occult disease process, the cause may remain undiscovered in 30% to 50% of patients despite exhaustive investigations. H capsulatum is an uncommon cause of granulomatous liver disease, and with its protean clinical presentation, a high index of suspicion is needed to make the diagnosis and avoid the potentially high fatality rate associated with disseminated infection.

Intermittent subcutaneous opioids: using an algorithm

Nurses and patients prefer the administration of injections via an indwelling subcutaneous cannula. Patients undergoing intermediate and minor surgery need improved pain relief. The algorithm provides a safe and acceptable mechanism for administering subcutaneous opioids more frequently.

Non-toxigenic Corynebacterium diphtheriae: two cases and review of the literature

Non-toxigenic Corynebacterium diphtheriae infections are being reported with increasing frequency. We present two cases of C. diphtheriae endocarditis requiring early valve replacement. Both cases were complicated by cerebral embolic phenomena and pseudoaneurysm formation in lower limb arterial vessels. Non-toxigenic C. diphtheriae septicaemia must be excluded when 'diphtheroids' are isolated from blood cultures.

Referral to specialized geriatric services. Which elderly people living in the community are likely to benefit?

PROBLEM BEING ADDRESSED

As the Canadian population ages, family physicians encounter increasing numbers of elderly people with medical, functional, psychological, and social difficulties. In the past two decades, most regions of Canada have developed systems of specialized geriatric services, available on a consultative basis, to assist family physicians evaluating and managing elderly patients with these difficulties. For many family physicians, however, it is often unclear which of their elderly patients are likely to benefit from referral to these geriatric services.

OBJECTIVE OF PROGRAM

Using an interdisciplinary approach, specialized geriatric services seek to optimize health, maximize function, promote independence, and prevent or delay institutionalization of elderly people. Yet not all elderly people benefit from referral to specialized geriatric services. This article offers a clear and clinically practical framework to help family physicians identify elderly patients in their practices who are likely to benefit from referral to specialized geriatric services.

MAIN COMPONENTS OF PROGRAM

By synthesizing previous work on the concept of frail elderly persons into a 2 x 2 matrix, the level and intensity of geriatric intervention most appropriate for different segments of the elderly population is clarified.

CONCLUSIONS

Using the simple approach described in this article, family physicians should be able to use available geriatric resources easily and efficiently to optimize the health and function of their elderly patients.

Grasping the marketing nettle. A professional development course for nurse practitioners in stoma care

Effective management and efficient use of resources are prerequisites for a high quality service. Marketing skills are now essential for nurses. These consist of nurses being able to prove they can offer an economically viable service and to argue the case for more resources. Regular use of patient questionnaires will elicit opinions on standards of care. The health service's biggest resource is its staff: improving channels of communication and creating areas of accountability will fulfil its potential.

Basal and stretch-augmented natriuretic peptide secretion by quiescent rat atria

Absolute rates of immunoreactive atrial natriuretic peptide (ANP) secretion were measured in vitro at 37 degrees C in noncontracting preparations of combined right and left rat atria at constant distending pressures of 0 or 5.1 mmHg in presence of 0.2 mM extracellular Ca2+ concentration [( Ca2+]o), 10 microM ryanodine, and either 1 microM saxitoxin or 10 microM tetrodotoxin. By systematic deletion of external Na+, K+, Mg2+, Cl-, or HCO3-, and reduction of [Ca2+]o, and by selective ion transport inhibitors, neither net transplasmalemmal fluxes of Na+, Cl-, HCO3-, and Mg2+ nor ryanodine-sensitive Ca2+ release from sarcoplasmic reticulum (SR) was found necessary for stretch augmentation of secretory rate (Ra). Ra 1) was near zero within 20 min when extracellular Na+ concentration = 0 and [Ca2+]o = 20 microM and within 5 min or less after preincubation with caffeine, 8-chlorophenylthioadenosine 3',5'-cyclic monophosphate, or at 18 degrees C; 2) was significantly decreased by Cd2+, Ni2+, the isoquinoline H-7, and trifluoperazine but not 100 microM ryanodine; 3) was increased by neomycin; and 4) had an apparent activation energy of 18.5 +/- 4.1 x 10(3) cal/mol between 23 and 42 degrees C. These experiments strongly implicated transplasmalemmal Ca2+ influx and cAMP but not SR Ca2+ release in control of Ra under the experimental conditions studied.

Localization of insulin-like growth factor-I mRNA in rat brain by in situ hybridization--relationship to IGF-I receptors

Recent evidence has demonstrated regional synthesis of insulin-like growth factor I (IGF-I) in rat brain, which is also known to contain widespread specific type I IGF receptors. In order to precisely define sites of IGF-I mRNA synthesis, and their relationship to IGF-I receptor sites, we have applied the techniques of in situ hybridization and in vitro receptor autoradiography in rat brain. Frozen sections of adult rat brain and liver were hybridized with 32P-labeled cDNA inserts for human IGF-I (780 base pairs) or a positive control transthyretin cDNA (1430 base pairs) probe, or a series of negative probes, followed by film or emulsion autoradiography. Receptor autoradiography was performed on similar sections using 125I-IGF-I in buffer, some chambers containing excess unlabeled IGF-I. Hybridization of IGF-I probe was clearly seen only in three major brain regions: the olfactory bulb, hippocampus and cerebellum, whereas transthyretin only hybridized to choroid plexus as expected, and other probes showed no hybridization. In olfactory bulb, hybridization was greatest in the internal granular and mitral cell layers, with lower levels in the glomerular layer, where IGF-I receptors were concentrated. In hippocampus, hybridization was to pyramidal cells of Ammon's horn in CA1 and CA2 layers and dentate gyrus, with some labeling in CA3. IGF-I receptors were most dense in CA2, CA3, CA4, and dentate gyrus. In cerebellum, hybridization was to the granule cell layer, with IGF-I receptors primarily in the adjacent molecular layer. We have clearly demonstrated precise sites of local IGF-I synthesis in adult rat brain, adjacent to, and sometimes overlapping sites of high density IGF-I receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

The expression of transthyretin mRNA in the developing rat brain

Specific cDNA and oligonucleotide probes were used to study the appearance of transthyretin mRNA in developing rat brain using Northern gel analysis, cytoplasmic dot hybridization, and in situ hybridization. Transthyretin mRNA in embryonic rat brain was found to be confined to the epithelial layer of the choroid plexus primordia appearing first in the fourth ventricle, followed by appearance in the lateral ventricles, and subsequently in the third ventricle. Transthyretin mRNA was localized in these cells from early stages of neuroepithelium differentiation, showing that it is a sensitive marker for the differentiation of the choroid plexus within the fetal brain.

Effect of treatment on Campylobacter pylori in peptic disease: a randomised prospective trial

This study investigated the effect of colloidal bismuth subcitrate and cimetidine on Campylobacter pylori in peptic disease. In 74% of 135 patients with peptic disease diagnosed at endoscopy C pylori was detected before treatment. Compared with cimetidine, colloidal bismuth subcitrate significantly decreased the incidence of C pylori after six weeks of treatment (p less than 0.001). In the colloidal bismuth subcitrate group, subsequent healing of the lesion was correlated with the clearance of C pylori, unlike in the cimetidine group. C pylori was strongly associated with the presence of histological gastritis, which was decreased by colloidal bismuth subcitrate (p less than 0.001).

Structure and expression of the rat transthyretin (prealbumin) gene

The rat transthyretin gene, 7.3 kilobase pairs (kb) long, with 14.5 kb of 5' flanking and 12.2 kb of 3' flanking region was cloned and characterized. The gene contained four exons. A "TATA box" sequence (5'-TATATAA-3') and a "CAAT box" sequence (5'-GTCAAT-3') were located 23 and 95 nucleotides upstream, respectively, from the major transcription start site. Nucleotides -51 to -189 were highly conserved (93% homology between rats and humans, 97% homology between rats and mice). Tandem repeats of sequences of 5'-AC-3' and 5'-ACACATGC-3' in the 5' flanking region, of 5'-GAAA-3' in the first intron, and of 5'-GT-3' in the third intron of the gene were observed. Using specific cDNA probes, tissue specificity and regulation of transthyretin mRNA biosynthesis during embryogenesis were analyzed. Transthyretin expression occurred first in the yolk sac, then decreased when expression increased in fetal liver. Presumptive choroid plexus cells in the inner lining of the neural tube expressed transthyretin early in gestation (11 days before birth) with a maximum immediately preceding the spurt of brain growth around birth. Partial hepatectomy of adult rats induced both an acute phase response and regenerative growth in liver. The decrease in transcription of the transthyretin gene in liver, which is characteristic for the acute phase response, was overridden by stimulation of gene expression after partial hepatectomy. This stimulation also affected transthyretin expression in choroid plexus.

Tunneling cell processes in myocytes of stretched mouse atria

Serial section electron micrographs of mouse atria stretched in vitro show that myocytes have cell processes which tunnel into adjacent myocytes for 8 microns or more. The tunneling cell processes (TCP) (diam 4-6.2 microns) lack myofibrils and organelles associated with atrial peptide secretion. The glycogen-rich TCP cytoplasmic matrix contains conspicuous tubules and vesicles originating from endoplasmic reticulum and resembling free sarcoplasmic reticulum (SR). TCP are surrounded by a plasmalemma derived from their myocyte of origin, the plasmalemma of the tunneled myocyte, and an intervening narrow compartment continuous with the interstitial space. Profiles having the characteristics cytoplasmic structure of TCP are also found both in the interstitial space between myocytes and near the longitudinal terminations where myocyte ends about on the interstitial space. We suggest that TCP tubules and vesicles may proliferate and/or transport in response to stretch, might be free SR, and may respond to stretch-activated changes in ionic composition or potential of the surrounding myocyte and narrow intercellular compartment.

Synthesis of a specific oligodeoxyribonucleotide probe and its use for studying proenkephalin A gene expression

A 44-mer, complementary to the coding region of bovine adrenal medullary proenkephalin A mRNA (ProEnkA mRNA) has been synthesized as a specific probe for this mRNA. Northern-blot hybridization analysis identified a single band in an RNA extract from bovine, ovine and porcine adrenal medullae. The molecular size of these hybridized bands (1400-1600 nucleotides) was in excellent agreement with that reported previously using cloned cDNA probes. In situ hybridization on bovine and ovine adrenal sections revealed that ProEnkA mRNA was localized selectively in cells at the outer margin of the medulla, a region rich in adrenaline-containing cells. This study both confirms and extends previous findings with cloned cDNA probes on the presence of high concentrations of ProEnkA mRNA in cells at the periphery of the adrenal medulla. In addition, it demonstrates the usefulness of synthetic oligodeoxyribonucleotides as specific and sensitive probes for the study of proenkephalin A gene expression.

Ultrastructural features of atrial peptide secretion

The ultrastructural bases of exocytotic extrusion of atrial peptides were reexamined in electron micrographs of thin-sectioned or freeze-fractured mouse atria. Exocytotic extrusion was demonstrated in both thin-sectioned and freeze-fractured atrial myocytes. Ultrastructural evidence suggested that the necks of plasmalemmal caveolae may constitute preformed pathways for extrusion of secretion from granules fusing with caveolae. Multiple subsarcolemmal foci with peripheral Golgi cisterns and accumulations of granules, indicating peripheral processing of secretory proteins, were striking features of mouse and rat atria, and were present but rare in sheep and dog atria. Conspicuous focal ellipsoidal deposits, a new structure, approximately 1.6-4.6 micron long and approximately 0.8-1.8 micron wide, consisting of amorphous cytoplasmic material that is penetrated peripherally by tubules connecting with secretion-containing "multivesicular bodies," were present in some mouse atrial myocytes, but were absent in myocytes of mouse ventricle and rat, dog, and sheep atria.

Utilization of psychotropic drugs in Saskatchewan: 1977-1980

Psychotropic drug use in Saskatchewan during 1977, 1978, 1979 and 1980 was determined. Approximately one in five prescriptions dispensed was for a psychotropic. About 20% of the population received psychotropic drugs in each year but use has declined slightly, especially that of tranquilizers. Psychotropic use increased with the patient's age and nearly two-thirds were women. Considerable caution should be exercised in making comparisons with other drug utilization studies. There may be substantial differences in the drugs selected for study, the categorization of these drugs, and the methodology used to analyze drug use. Also, most studies are based on data that is from a decade old or older. Moreover, most if not all other studies on drug use are based on sample surveys (from different sampling universes), whereas the present study is based on the entire population. Nevertheless, some generalizations may be valid. Since non-formulary drugs are excluded, the findings should be regarded as conservative. Examples of non-formulary drugs considered to be psychotropic include antispasmodic/tranquilizer/sedative combinations (example: Librax, Donnatal), combination hypnotics (example: Tuinal, Mandrax), and some combination analgesics (example: propoxyphene compounds, pentazocine compound, oxycodone compound).

Sterological measurements of cardiac ultrastructures implicated in excitation-contraction coupling

Electron micrographs of osmium-fixed left ventricles from 200-g female rats were analyzed by stereological techniques. By the use of equations developed by H. Sitte it was possible to determine volume fractions of organelles and absolute membrane areas per unit cell volume for cellular membrane systems implicated in excitation-contraction coupling. The fractions of cell volume were: mitochondria 0.34, myofibrils 0.481, T-system 0.012, total sarcotubules 0.035, other 0.13. The membrane areas per unit cell volume (mum(2)/mum(3)) were: external sarcolemma 0.27, external sarcolemma + T-system 0.34, total sarcotubules 1.3. Diads made up 0.08 of sarcotubular volume and 0.12 of sarcotubular membrane area. 0.14 of the external sarcolemmal membrane area was involved in diadic complexes with underlying subsarcolemmal cisterns.