Self-report and urine drug screen concordance among women with co-occurring PTSD and substance use disorders participating in a clinical trial: Impact of drug type and participant characteristics

BACKGROUND

Self-report measures are important in substance use assessment, yet they are susceptible to reporting errors. Urine drug screens (UDS) are often considered a more valid alternative. However, collecting in-person UDS may not always be feasible, contributing to the need to understand factors that influence the validity of self-reported substance use.

METHODS

In this secondary analysis of data from 295 women with co-occurring PTSD and substance use disorders (SUD) who participated in a clinical trial testing behavioral interventions, we examined concordance and discordance between self-reported drug use and associated UDS results. Generalized linear mixed models were used to examine the impact of treatment type and participant characteristics on the associations between self-reported drug use and UDS results.

RESULTS

Findings revealed higher disagreement between self-report and UDS for opioids and sedatives (ranging from.77 to.90) and lower disagreement rates for cannabis and cocaine (ranging from.26 to.33). Treatment type was not a significant moderator of the associations between self-report and UDS across all drugs. Among those with a positive opioid UDS, those who reported employment in the past three years were more likely to self-report no opioid use compared to their counterparts without employment in the past three years.

CONCLUSIONS

Findings add to the literature that supports the validity of self-reported cannabis and cocaine use. The greater discrepancies between self-report and UDS test results of opioids and sedatives suggest adjunctive UDS may be required, although a variety of factors other than inaccurate self-report may be associated with this discrepancy.

Feasibility and Acceptability of a Novel Online Program for Mental Health Carers

Objective

To evaluate the feasibility and acceptability of a new online program (Minds Together ) for carers of a person with depressive or anxiety symptoms.

Methods

Using a two-arm randomised controlled trial design, 108 carers of a person with depressive or anxiety symptomology aged 16 years or over (89% female; mean age 50 years) received immediate or delayed access to the Minds Together program. Feasibility was measured using program activation and survey completion rates. Acceptability was measured using a project-specific satisfaction scale, semi-structured interviews, and program completion metadata. The study used intention-to-treat (ITT) analysis for participant-reported outcomes (carer burden, coping self-efficacy) across groups.

Results

Feasibility and acceptability thresholds were consistent with similar studies: 59% activated their program account, 47% met the program completion threshold, and almost all reported satisfaction with the program. The ITT indicated trends in increased coping self-efficacy and reduced carer burden for the Intervention group, compared to the Waitlist control.

Conclusions

The Minds Together program is a feasible and acceptable program for carers supporting a person with depressive or anxiety symptomology. Results support exploration of the program's efficacy in a full-scale RCT.

Paving the way for application of next generation risk assessment to safety decision-making for cosmetic ingredients

Next generation risk assessment (NGRA) is an exposure-led, hypothesis-driven approach that has the potential to support animal-free safety decision-making. However, significant effort is needed to develop and test the in vitro and in silico (computational) approaches that underpin NGRA to enable confident application in a regulatory context. A workshop was held in Montreal in 2019 to discuss where effort needs to be focussed and to agree on the steps needed to ensure safety decisions made on cosmetic ingredients are robust and protective. Workshop participants explored whether NGRA for cosmetic ingredients can be protective of human health, and reviewed examples of NGRA for cosmetic ingredients. From the limited examples available, it is clear that NGRA is still in its infancy, and further case studies are needed to determine whether safety decisions are sufficiently protective and not overly conservative. Seven areas were identified to help progress application of NGRA, including further investments in case studies that elaborate on scenarios frequently encountered by industry and regulators, including those where a ‘high risk’ conclusion would be expected. These will provide confidence that the tools and approaches can reliably discern differing levels of risk. Furthermore, frameworks to guide performance and reporting should be developed.

Gingival Fibroma: An Emerging Distinct Gingival Lesion with Well-Defined Histopathology

Gingival growths, barring a few are mostly reactive and seldom exhibit significant true neoplastic potential. The common etiology is local irritation from dental plaque/calculus, trauma as well as medication-related overgrowth. Such lesions are easily distinguishable and categorized into diagnoses such as pyogenic granuloma, peripheral ossifying fibroma, etc. We present a previously undescribed, but commonly encountered, reactive gingival growth with unique histologic features and suggest the diagnostic term "gingival fibroma." An IRB approved retrospective review of the University of Florida Oral Pathology Biopsy Service encompassing years 2010-2019, was performed to select cases. Demographics, clinical data, and microscopic diagnoses were recorded and analyzed. Four board-certified oral and maxillofacial pathologists agreed upon and established the diagnostic criteria. These are: a prominent fibromyxoid stroma, variable cellularity, a whorled or storiform pattern of arrangement of the cellular elements, lack of significant inflammation or vascularity, and complete absence of calcification, and/or odontogenic islands. A total of 60 cases met all criteria and were included in the study. Age range in years was 14-87 with the mean at 45.11 years. A striking female predilection (90%) was noted. Approximately 62% of cases were reported on the maxillary gingiva, followed by 38.3% in the mandibular gingiva. Majority, 66.7% were in the anterior incisor region followed by 11.7% in the canine/first premolar areas. All lesions were submitted as excisional biopsy, and 4 cases recurred within 2-3 years of excision. In all cases, lesional tissue appeared to extend to the surgical base of the specimen. We present 60 cases of a histologically unique entity occurring exclusively on the gingiva and introduce the diagnostic term "Gingival Fibroma" for these lesions. Further studies with adequate clinical follow-up may help understand the exact clinical behavior of these lesions.

Neurosurgical aspects of abusive head trauma management in children: a review for the training neurosurgeon

The management of head trauma in children from suspected abuse is multidisciplinary. The primary role of neurosurgeons is to manage the acute clinical situation. They also have a secondary role in assisting others to determine the cause of the injury and prevent recurrences. This article aims to guide the trainee neurosurgeon on management of this patient group according to current literature.

Clear cell changes in salivary gland neoplasms: A 20-year retrospective study

BACKGROUND

Clear cells are observed histopathologically in both benign and malignant neoplasms but their presence in salivary gland tumors has not been extensively documented.

MATERIAL AND METHODS

With IRB approval, the archive of the University of Florida College of Dentistry oral pathology biopsy service was retrospectively searched from 1994-2014 for all benign and malignant salivary tumors. Epidemiological data, tumor location and duration, and type of tumor were recorded. A four reviewer panel examined the original slides. Reviewers scaled each case as 0 (no clear cells present), 1 (few to focal clear cells), 2 (less than 50% clear cells), and 3 (greater than 50% clear cells).

RESULTS

A total of 535 cases were included of which 48% of tumors displayed 0 clear cells (257/535), 31.4% (168/535) scored 1, 13.6% (73/535) scored 2, and 7% (37/535) scored 3. Of the 251 (47%) malignant neoplasms, 64% (160/251) demonstrated 0-1 clear cell change, while 36% (91/251) showed a score of 2-3. For the total 284 (53%) benign tumors, 93% (265/535) scored 0-1 and 7% (19/535) scored a 2-3 range. No statistical difference was noted for gender, age, or duration of time present in regards to presence or absence of clear cells. Statistically significant differences in clear cell presence were found between location groups, between benign and malignant diagnosis, and between specific diagnostic groups.

CONCLUSIONS

This study demonstrates the frequent presence of increased numbers of clear cells in oral salivary malignancies and highlights salivary gland differential diagnoses when presented with clear cell changes.

Obesity is associated with increased asthma severity and exacerbations, and increased serum immunoglobulin E in inner-city adults

BACKGROUND

Obesity is associated with increased asthma and atopy.

OBJECTIVE

To determine whether or not obesity in inner-city adults is associated with increased asthma prevalence, severity and exacerbations and IgE responses.

METHODS

This retrospective study involved 246 adults with asthma and other atopic disorders who were seen at an asthma clinic in New York City between 1997 and 2010. Height, weight, asthma diagnosis and symptoms, peak flow (PF), spirometry, serum IgE levels and white blood cell differentials were recorded.

RESULTS

Asthmatic patients had higher body mass index than non-asthmatics (median, interquartile range: 30.5, 10.2 vs. 27.8, 8.8; Mann-Whitney U-test, P = 0.0006). Class I and II/III obesity were associated with increased asthma (I: OR: 2.35, 95% CI: 1.04-5.34, P = 0.04; II/III: OR: 3.25, 95% CI: 1.36-7.74, P = 0.008). Class I and II/III obesity were associated with worsened asthma severity (ordinal logistic regression; I: OR: 4.23, 95% CI: 1.61-11.06, P = 0.003; II/III: OR: 2.76, 95% CI: 1.08-7.09, P = 0.03). Class II/III obesity was associated with increased asthma exacerbations requiring oral corticosteroids (repeated measures logistic regression, OR: 1.13, 95% CI: 1.03-1.25; P = 0.01) and increased requirement of inhaled corticosteroid for long-term asthma management (OR: 1.45, 95% CI: 1.29-1.62; P < 0.0001). In asthmatics, class II/III obesity was associated with decreased PF (general linear model, least squares mean ± SEM: 333.8 ± 37.4 vs. 396.2 ± 32.1 L/min; P = 0.007), forced expiratory volume in 1 s (75.2 ± 4.6 vs. 88.4 ± 5.6%; P = 0.03) and forced vital capacity (83.2 ± 4.7 vs. 109.2 ± 6.0%; P = 0.0002) and increased serum IgE (480.2 ± 88.3 vs. 269.0 ± 66.6 IU/mL; P = 0.04) and neutrophils (66.6 ± 3.7 vs. 60.1 ± 3.8%; P = 0.02). Class I obesity was also associated with increased serum IgE (458.7 ± 68.9, P = 0.03).

CONCLUSION AND CLINICAL RELEVANCE

Obesity in inner-city adults may be both a risk and exacerbating factor for atopic asthma.

Copper(II)-selective chelation improves function and antioxidant defences in cardiovascular tissues of rats as a model of diabetes: comparisons between triethylenetetramine and three less copper-selective transition-metal-targeted treatments

AIMS/HYPOTHESIS

Treatment with the Cu(II)-selective chelator triethylenetetramine (TETA) improves cardiovascular disease in human patients, and cardiac and vascular/renal disease in rats used as a model of diabetes. Here we tested two hypotheses: first, that TETA elicits greater improvement in organ function than less Cu-selective transition-metal-targeted treatments; second, that the therapeutic actions of TETA are consistent with mediation through suppression of oxidative stress.

METHODS

Rats were made diabetic with streptozotocin (55 mg/kg, i. v.) and treated from 8 weeks after disease induction for the following 8 weeks with effective dosages of oral TETA, or one of three less Cu-selective transition-metal-targeted treatments: D-penicillamine, deferiprone or Zn acetate. Treatment effects were measured in ex vivo cardiac and aortic tissues, plasma and urine.

RESULTS

Diabetes damaged both cardiac and renal/vascular function by impairing the ability of cardiac output to respond physiologically to rising afterload, and by significantly elevating the urinary albumin/creatinine ratio. Diabetes also lowered total antioxidant potential and heparan sulphate levels in cardiac and arterial tissues, and serum ferroxidase activity, whereas it elevated urinary heparan sulphate excretion. TETA treatment rectified or partially rectified all these defects, whereas the other three experimental treatments were ineffectual. By contrast, none of the four drug treatments lowered diabetes-mediated elevations of plasma glucose or lipid concentrations.

CONCLUSIONS/INTERPRETATION

TETA may limit the cardiac and renal/vascular damage inflicted by diabetes through its actions to reinforce antioxidant defence mechanisms, probably acting through selective chelation of 'loosely-bound'/chelatable Cu(II). It may also improve heparan sulphate homeostasis and bolster antioxidant defence by increasing vascular extracellular superoxide dismutase activity. Urinary albumin/creatinine ratio might prove useful for monitoring TETA treatment.

Birds' tails as signaling devices: markings, shape, length, and feather quality

While exaggerated length and ornamental shapes are confirmed sexually selected tail traits in birds, the signal function of tail markings has received less study. Signal roles for tail markings as amplifiers of length, shape, and feather quality are discussed, and the role of tail markings as feather-quality handicaps is proposed: absence of melanin increases damage and abrasion. Predicted correlations of tail markings with other tail traits are derived for these signal roles. A comparative study of the relationships between these tail traits in an entire avifauna, the western Palearctic, tested the predictions. Tail displays were present in nearly 80% of species, associated with greater long-tailedness, but not all displayed tails had markings or ornamental shape. The incidence of marks across tail shapes and the combinations of marks indicate that tail markings act as handicaps or amplifying handicaps of tail feather quality. Tail elongation and ornamental shapes could act as additional handicaps of feather quality-that is, they could be multipurpose signals. Incorporation of revealing indicators such as feather damage and associated handicap and/or amplifying traits may allow a reduction in the cost of signaling while maintaining signal reliability and, hence, influence sexual selection in complex signaling systems.

Plastic baton round injuries

OBJECTIVES

To review the injuries resulting from a new plastic baton round.

METHODS

Review of case notes of patients presenting with injuries caused by plastic baton rounds over a four month period in Northern Ireland.

RESULTS

Twenty nine patients were identified, 28 with 30 injuries were included in the study. Eighty nine per cent were male; the average age was 24.3 years. Seven patients required admission. There were no fatalities. Five injuries were to the upper limbs and 16 to the lower limbs. Three patients sustained pulmonary contusions. There were no head injuries.

CONCLUSIONS

Although the numbers in this study are small it should be noted that no patient suffered a face, neck, or head injury. This is in contrast with previous studies in which up to 41.4% of attendances were for face, neck, or head injuries. In this study there were seven injuries to the trunk. Of the 14 deaths attributable to plastic baton rounds in Northern Ireland, all have been the result of head or chest trauma. The use of plastic baton rounds has decreased and, while a reduction in head injuries is noted, potentially serious chest injuries are still occurring. It is vital that guidelines on firing are adhered to. A large proportion of people who have been struck by plastic baton rounds do not attend an accident and emergency department and therefore doctors must be aware of patients with potentially serious injuries presenting late.

Once-daily budesonide inhalation suspension in infants and children < 4 and > or = 4 years of age with persistent asthma

BACKGROUND

Budesonide inhalation suspension (Pulmicort Respules; AstraZeneca LP, Wilmington, DE), a nebulized corticosteroid, was developed for use in infants and young children with persistent asthma.

OBJECTIVE

To compare the efficacy and safety of once-daily budesonide inhalation suspension in children < 4 years of age and in those > or = 4 years of age with persistent asthma.

METHODS

A retrospective analysis stratified by age group was performed on data from two randomized, double-blind, placebo-controlled, parallel-group studies that evaluated the efficacy and safety of budesonide inhalation suspension 0.25 mg, 0.5 mg, or 1.0 mg once daily for 12 weeks in children 6 months to 8 years of age with persistent asthma. Clinical assessments included nighttime and daytime asthma symptoms, breakthrough medication use, adverse events, and hypothalamic-pituitary-adrenal-axis function.

RESULTS

In both randomized studies, budesonide inhalation suspension demonstrated statistically significant improvement in nighttime and daytime asthma symptom scores compared with placebo. In the retrospective analysis of pooled data from these studies, the efficacy of budesonide was maintained when children were stratified by age group. Clinical improvements from baseline in nighttime and daytime asthma symptom scores were observed in both age groups at all budesonide inhalation suspension dose levels. No significant differences were observed between age groups in breakthrough medication use in any of the treatment groups. No differences were observed in the incidence of adverse events between the two age groups, and significant (P < 0.01) effect on hypothalamic-pituitary-adrenal-axis function was apparent only in children < 4 years of age at the 0.25-mg dose level.

CONCLUSIONS

Once-daily budesonide inhalation suspension is effective in the treatment of persistent asthma in children aged < 4 and > or = 4 years of age.

p22 is a novel plasminogen fragment with antiangiogenic activity

Tumor or tumor-associated cells cleave circulating plasminogen into three or four kringle-containing antiangiogenic fragments, collectively referred to as angiostatin. Angiostatin blocks tumor growth and metastasis by preventing the growth of endothelial cells that are critical for tumor vascularization. Here, we show that cancer and normal cells convert plasminogen into a novel 22 kDa fragment (p22). Production of this plasminogen fragment in a cell-free system has allowed characterization of the structure and activity of the protein. p22 consists of amino acid residues 78-180 of plasminogen and therefore embodies the first plasminogen kringle (residues 84-162) as well as additional N- and C-terminal residues. Circular dichroism and intrinsic fluorescence spectrum analysis have defined structural differences between p22 and recombinant plasminogen kringle 1 (rK1), therefore suggesting a unique conformation for kringle 1 within p22. Proliferation of capillary endothelial cells but not cells of other lineages was selectively inhibited by p22 in vitro. In addition, p22 prevented vascular growth of chick chorioallantoic membranes (CAMs) in vivo. Furthermore, administration of p22 at low dose suppressed the growth of murine Lewis lung carcinoma (LLC) metastatic foci in vivo. This is the first identification of a single kringle-containing antiangiogenic plasminogen fragment produced under physiological conditions.

Safety of budesonide inhalation suspension (Pulmicort Respules) after up to 52 weeks of treatment in infants and young children with persistent asthma

Three open-label extension trials evaluated the safety of budesonide inhalation suspension (BIS; Pulmicort Respules) in 670 children (8 months-9 years of age) with mild-to-severe persistent asthma. Patients were randomized to receive either BIS or conventional asthma therapy (CAT) for 52 weeks. The percentage of patients who discontinued because of clinical adverse events was low and similar among the CAT (0.4%) and BIS (0.7%) groups. After adjusting for length of time in the studies, there were no clinically relevant differences between the BIS and CAT groups in the type, incidence, or intensity of adverse events; vital signs or physical examination outcomes; or changes in clinical laboratory evaluations or oral fungal cultures.

Asthma and allergy in Albania and the UK

In the first phase of the International Study of Asthma and Allergies in Childhood, a large difference in occurrence of asthma symptoms was seen between children in Albania and the UK. We did skin-prick tests with various allergens and measured peak expiratory flow rate in about 1000 children from each country. A large difference in the proportion of exercise-induced bronchial reactivity was evident between children from Albania and the UK (0.8% vs 5.4%, respectively). However, the frequency of allergic sensitisation was closely similar (15.0% vs 17.8%, respectively). These results suggest that large geographical variations in asthma prevalence can arise without differences in frequency of atopy.

The gene encoding the immunoregulatory signaling molecule CMRF-35A localized to human chromosome 17 in close proximity to other members of the CMRF-35 family

The immunoregulatory signaling (IRS) family includes several molecules, which play major roles in the regulation of the immune response. The CMRF-35A and CMRF-35H molecules are two new members of the IRS family of molecules, that are found on a wide variety of haemopoietic lineages. The extracellular functional interactions of these molecules is presently unknown, although CMRF-35H can initiate an inhibitory signal and is internalized when cross-linked. In this paper, we described the gene structure for the CMRF-35A gene and its localization to human chromosome 17. The gene consists of four exons spanning approximately 4.5 kb. Exon 1 encodes the 5' untranslated region and leader sequence, exon 2 encodes the immunoglobulin (Ig)-like domain, exon 3 encodes the membrane proximal region and exon 4 encodes the transmembrane region, the cytoplasmic tail and the 3' untranslated region. A region in the 5' flanking sequence of the CMRF-35A gene, that promoted expression of a reporter gene was identified. The genes for the CMRF-35A and CMRF-35H molecules are closely linked on chromosome 17. Similarity between the Ig-like exons and the preceding intron of the two genes suggests exon duplication was involved in their evolution. We also identified a further member of the CMRF-35 family, the CMRF-35J pseudogene. This gene appears to have arisen by gene duplication of the CMRF-35A gene. These three loci - the CMRF-35A, CMRF-35J and CMRF-35H genes-form a new complex of IRS genes on chromosome 17.

Comparable efficacy of administration with face mask or mouthpiece of nebulized budesonide inhalation suspension for infants and young children with persistent asthma

A randomized, double-blind, placebo-controlled, parallel-group study including 481 children at 37 centers in the United States demonstrated the efficacy and safety of budesonide inhalation suspension in doses of 0.25 mg once daily, 0.25 mg twice daily, 0.5 mg twice daily, and 1.0 mg daily in infants and young children with persistent asthma. The retrospective analysis presented here compares the efficacy of treatment with the suspension administered through a face mask or mouthpiece. All patients receiving budesonide inhalation suspension via face mask or mouthpiece showed clinical improvements in nighttime and daytime asthma symptoms as compared with administration of a placebo. The improvements were of similar magnitude as those observed in an analysis of all patients treated. Improvements in nighttime asthma symptoms were statistically significant with budesonide at 0.25 mg daily (p = 0.040), 0.25 mg twice daily (p = 0.008), and 0.5 mg twice daily (p = 0.046) delivered by face mask. In patients using mouthpieces, nighttime asthma symptoms improved significantly in the 0.25-mg twice-daily (p = 0.005) and 1.0-mg daily (p = 0.035) groups. Patients receiving budesonide at 0.5 mg twice daily via a face mask improved significantly in daytime asthma symptoms (p = 0.009). The use of breakthrough medication was reduced in patients receiving budesonide via face masks or mouthpieces relative to placebo, and treatment was well tolerated in all study groups. This retrospective analysis suggests that nebulized budesonide inhalation suspension can be administered effectively by either face mask or mouthpiece to young children with persistent asthma.

Vitamin D-deficient rickets: a multifactorial disease

We present a case of an African-American child with vitamin D-deficient rickets. In addition to being solely breast-fed for the period of 1 year, he resided in New England, where exposure to ultraviolet light is limited owing to its northern latitude and long cold winters. He presented with classical signs of nutritional rickets and was immediately responsive to treatment with vitamin D supplementation.

A transmissible trematode affects the direction and rhythm of movement in a marine gastropod

Microphallus piriformes (Trematoda) is unusual in having only two hosts and no motile free-living stages. The intermediate host, the rough periwinkle, Littorina saxatilis, is present year-round on rocky shores and has a high parasite prevalence near breeding colonies of the definitive host, the herring gull, Larus argentatus, which is present in numbers at these sites for only 4 months per year. Given the seasonal availability of gulls for infection and a low incidence of periwinkles in the normal diet of herring gulls, specialized transmission between stages appears necessary for maintenance of the parasite's life cycle. We investigated the hypothesis that M. piriformes alters its intermediate host's behaviour during the gull's breeding season in a manner that may facilitate predation of the infected periwinkle by breeding gulls. We studied the movements of periwinkles during simulated tidal cycles in the laboratory; parasite status was established subsequently. Periwinkles with mature infections moved further upwards but showed less downwards and horizontal movement than uninfected periwinkles. The movement of periwinkles with immature (nontransmissible) infections was less affected by the parasite. During the tidal cycle, infected and uninfected periwinkles differed in both timing and extent of movement. A field experiment confirmed the greater upwards movement of infected periwinkles. The parasite-induced changes in periwinkle behaviour may increase the chances of predation by the final host and could represent an important survival strategy for M. piriformes. Copyright 2000 The Association for the Study of Animal Behaviour.

Current status of the Maze procedure for the treatment of atrial fibrillation

Since the first patient underwent the Maze procedure on September 25, 1987, 346 patients have undergone this operation for the treatment of atrial fibrillation. The procedure was designed as an open-heart operation performed through a median sternotomy. It underwent 2 major modifications relatively early in the series, evolving into the so-called Maze-III procedure, which has been used exclusively since April 16, 1992. Since that time, the Maze-III procedure has been adapted to allow it to be done by minimally invasive techniques. In addition, we recently performed the entire procedure in 2 patients without the use of cardiopulmonary bypass. The operative mortality rate has remained at 2% to 3%. This includes patients undergoing concomitant high-risk cardiac surgical procedures and all re-do cases. The overall success rate in curing atrial fibrillation has been 99%. The procedure itself has been shown to cause no permanent damage to the sinus node. The left atrium has been documented to function long-term postoperatively in 93% of patients and the right atrium functions in 99% of patients. The Maze-III procedure remains the surgical procedure of choice for the treatment of medically refractory atrial fibrillation.

The Maze-III procedure combined with valve surgery

Previous studies have suggested that the Maze procedure is not as effective in controlling atrial fibrillation when the arrhythmia is associated with significant valvular heart disease. In this study, we evaluate our own results in 83 patients who underwent 96 valve procedures in combination with the Maze-III procedure. Our results indicate that the Maze-III procedure is just as safe and effective in controlling atrial fibrillation associated with valvular heart disease as it is in controlling atrial fibrillation not associated with valvular heart disease.

The uptake of calcium by isolated chromaffin granules of the adrenal medulla

Bovine chromaffin secretory granules were purified by isopycnic Metrizamide gradient centrifugation and their Ca2+ sequestration pathways were characterized. The rate of Ca2+ sequestration at 37 degrees C was first order, with a maximal uptake of 26.9 +/- 0.46 (mean +/- S.D., n = 3) nmol Ca2+/mg protein and a first order rate constant (k) of 0.046 +/- 0.002 min-1. At 4 degrees C the rate of uptake was substantially attenuated, with only 2.47 +/- 0.2 (mean +/- S.D, n = 3) nmol Ca2+/mg protein sequestered in 60 min. Ca2+ sequestration was 93% inhibited by 180 mM NaCl [I50% of 78.7 +/- 9.3 mM NaCl (mean +/- S.D., n = 11)] but only slightly inhibited by KCl or MgCl2. Ca2+ sequestration was not stimulated by incubation with MgATP but was inhibited by 57% after incubation with 30 microM monensin. Ca2+ sequestration was dependent on extravesicular Ca2+ with half-maximal sequestration at pCa2+ 6.81 +/- 0.028 (mean +/- S.D., n = 3). Sequestered Ca2+ could be exchanged with external 45Ca2+, the exchange rate was first order (k of 0.042 +/- 0.004: mean +/- S.D., n = 3) and saturated at 27.7 +/- 1.1 nmol Ca2+/mg (mean +/- S.D., n = 3). The Ca2+/Ca2+ exchange system was totally inhibited by NaCl or KCl but only slightly by MgCl2. About 75% of sequestered 45Ca2+ could be released by incubation with NaCl, but only 8% was released by incubation with KCl. Half-maximal release of sequestered 45Ca2+ required 69.3 +/- 12.2 mM NaCl (mean +/- S.D., n = 3). The Na+-induced release of sequestered 45Ca2+ was rapid, t0.5 of 2.80 +/- 0.63 min (mean +/- S.D., n = 3) and inhibited at 4 degrees C. The concurrent incubation of chromaffin granules with 45Ca2+ and either annexin proteins V or VI resulted in attenuated uptake of 45Ca2+. These results suggest that Ca2+ uptake in adrenal chromaffin granules is regulated by Na+ and Ca2+ gradients and also possibly by annexins V and VI.