Cardiovascular structure and function assessed by MRI in healthy South Asians compared to White Europeans: a UK Biobank study

Background

There is limited data on ethnic specific comparisons for measures of cardiovascular structure and function in healthy cohorts. Echocardiographic data indicate South Asian's (SAs) have smaller mass and evidence of more concentric remodelling compared to White Europeans (WEs). Furthermore, there is no data published for strain or strain rates.

Purpose

To compare Cardiac Magnetic Resonance (CMR) derived measures of structure and function between age and sex matched healthy SAs and WEs from the UK biobank cohort.

Methods

South Asian and WE participants from the UK Biobank who underwent CMR imaging were included. Individuals with a history of cardiovascular disease, hypertension, obesity (BMI ≥30 kg/m2 in WEs and ≥27 kg/m2 in SAs) and diabetes were excluded. Ethnic groups were matched according to age and sex at recruitment. Cine images (bSSFP) were analysed blinded to participant details using commercially available software. Left ventricular (LV) mass, LV volumes, global longitudinal and circumferential systolic strain (GLS and GCS), together with peak early diastolic strain rates (PEDSR), were obtained. Data distributions were assessed and T-Test or Man Whitney U conducted as appropriate.

Results

Datasets from the UK biobank were screened (n=45000). After applying exclusion criteria, 111 pairs of matched SAs and WEs were available for analysis (n=69 male and n=42 female matched pairs). Mean age of the entire cohort was 58±8 years. Data has been corrected according to body surface area (BSA),(males: WE 2.0±0.1 vs SA 1.8±0.1 m2, p≤0.001; females: WE 1.7±0.2 vs SA 1.6±0.1 m2, p≤0.001). There was no difference in heart rate (males: WE 64.5±9.3 vs SA 65.8±9.6 bpm, p=0.113; females: WE 66.2±7.8 vs SA 69.5±10.3 bpm, p=0.125). Results by sex and ethnicity are displayed in table 1. In males there was no difference in ejection fraction (EF) or indexed LV end diastolic volume (LVEDV). However indexed mass and mass/volume ratio were significantly lower in SAs, and GLS but not GCS was significantly higher than in SAs. Longitudinal PEDSR were significantly higher in SAs than in WE. By contrast, SA females had significantly lower EF with no difference in indexed LVEDV compared to WE females. However, as seen with the males SA females had significantly lower indexed LV mass and mass/volume ratio compared to WE females. Finally, both GLS and GCS were significantly higher in SAs compared to WE females, whereas there was no difference in longitudinal PEDSR.

Conclusion

Substantial differences in cardiovascular structure and function exist between SA and WE ethnic groups, in both men and women. Contrary to previous echocardiographic studies, LV volumes were similar between ethnicities and SA have less, not increased, concentric remodelling than WE. These findings highlight the need for ethnicity and sex-specific healthy reference ranges derived from CMR.

Funding Acknowledgement

Type of funding sources: None.

The amplifying influence of increased ocean stratification on a future year without a summer

In 1816, the coldest summer of the past two centuries was observed over northeastern North America and western Europe. This so-called Year Without a Summer (YWAS) has been widely attributed to the 1815 eruption of Indonesia's Mt. Tambora and was concurrent with agricultural failures and famines worldwide. To understand the potential impacts of a similar future eruption, a thorough physical understanding of the YWAS is crucial. Climate model simulations of both the 1815 Tambora eruption and a hypothetical analogous future eruption are examined, the latter occurring in 2085 assuming a business-as-usual climate scenario. Here, we show that the 1815 eruption drove strong responses in both the ocean and cryosphere that were fundamental to driving the YWAS. Through modulation of ocean stratification and near-surface winds, global warming contributes to an amplified surface climate response. Limitations in using major volcanic eruptions as a constraint on cloud feedbacks are also found.

Abstract P5-09-02: Impact of therapeutic complexity on practice patterns for metastatic breast cancer (MBC) in the United States: Results of a 2-phase national study

Background: The rapidly changing clinical management of MBC has challenged the ability of clinicians to understand and integrate new data, which relates directly to the quality of clinical care and is a key determinant of patient outcomes. This study was designed to determine the potential impact of the increased clinical complexity of decision making in MBC on optimal patient care by quantifying professional practice gaps and barriers among oncology specialists at academic medical centers and community clinic settings in the United States.

Methods: From October 2014 to February 2015, 216 actively practicing US oncology specialists with a caseload of ≥1 patient/year with MBC were recruited to participate in a 2-phase national needs assessment study. In the first, qualitative phase, 35 participants consented to a 45-minute telephone interview focused on the personal, contextual, and behavioral factors that influence their clinical reasoning process in diagnosis and treatment of MBC. Findings from this initial phase informed the second phase of the study. This quantitative phase included an online survey comprising specific multiple choice questions, semantic differential rating scales, and case vignettes. Respondents' (N = 181) answers to these questions were compared with optimal answers, as identified by treatment guidelines and MBC experts.

Results: Eight core practice gaps were identified through combined analysis of data from the in-depth interviews and online surveys. Of note, only 15% of respondents agreed with the experts' choice of letrozole + palbociclib as initial treatment for a postmenopausal patient with HR+ MBC with bone and visceral lesions after a prolonged response to adjuvant endocrine therapy. Survey respondents indicated that they use chemotherapy substantially more frequently than experts when treating patients with HR+ MBC. Only 36% of respondents' current practice matched expert recommendations regarding management of toxicity associated with exemestane + everolimus and 32% opted for management strategies with a risk of worsening treatment-related toxicity. Just over 30% of respondents agreed with the expert choice of ado-trastuzumab emtansine as second-line therapy for HER2+ MBC after progression on trastuzumab/paclitaxel. In addition, a minority of respondents knew the mechanisms of action of newly approved (palbociclib [45%]) and investigational agents, including dovitinib (19%), neratinib (30%), pembrolizumab (49%), and pictilisib (28%).

Conclusions: A significant percentage of US oncology specialists are not applying optimal care in patients with MBC. Most notably, this study indicated that participants overuse chemotherapy in patients with HR+ MBC, suboptimally manage treatment-related toxicities, and are challenged to select optimal therapy for HER2+ MBC patients who progress on previous therapy. Finally, a lack of familiarity with mechanisms of action of approved and promising investigational agents in MBC may lead to delays in the appropriate integration of new agents or indications into clinical practice. A full review of the study results and recommendations will be presented.

Citation Format: Quill TA, Jahanzeb M, Obholz KL, Brady E, Howson A, Rasulina M, Willis C, Hurvitz S. Impact of therapeutic complexity on practice patterns for metastatic breast cancer (MBC) in the United States: Results of a 2-phase national study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-09-02.

Six-year follow-up study on the effect of combined anterior and posterior spinal fusion on lung function and quality of life in young people with adolescent idiopathic scoliosis

OBJECTIVES

The effects of spinal surgery on lung function and quality of life (QoL) are important patient outcomes. Long-term follow-up of lung function and QoL in those undergoing combined anterior and posterior spinal fusion (A/PSF) for adolescent idiopathic scoliosis (AIS) is poorly documented with only one study extending beyond 2 years, though available evidence points to a decrement in lung function. Our study evaluated long-term change in lung function and QoL following A/PSF for AIS.

DESIGN

Prospective cohort study.

PATIENTS

Patients with AIS.

SETTING

Tertiary paediatric respiratory centre and national spinal service.

DESIGN

Spirometry was performed along with QoL (Scoliosis Research Society-22 (SRS-22) questionnaire). Paired t test and one-way analysis of variance were used to compare pre-A/PSF and post-A/PSF data.

RESULTS

Data were available for 12 patients (9 female) who underwent A/PSF at mean 13.8 (range 11.8-15) years. Mean follow-up was undertaken 5.8 (range 4.1-6.8) years postoperatively. Height increased from mean (SD) 169 (9) cm preoperatively to 175 (5) cm at follow-up (p<0.01). Scoliosis corrected from 100 (15)° to 29 (11)° (p<0.001). Mean (SD) forced expiratory volume in 1 s was -3.4 (1.4) z scores preoperatively versus -3.3 (1) z scores postoperatively (p=0.85); and forced vital capacity was -3.4 (1.7) ) z scores pre-A/PSF and -3.4 (1.1) z scores post-A/PSF (p=0.83). SRS-22 scores improved mean (SD) of 3.6 (0.3) preoperatively to 4.2 (0.3) at 2 years postoperatively, and 4.4 (0.4) at 6 year follow-up (p<0.001, analysis of variance). High patient satisfaction rates (4.8 (0.3)) were recorded. No correlation was noted between changes in forced expiratory volume in 1 s (r=-0.15, p=0.63) or forced vital capacity (r=-0.12, p=0.71) and change in long-term SRS-22 score.

CONCLUSIONS

Long-term follow-up of patients with AIS suggests no deficit in pulmonary function, while QoL shows incremental improvement and patient satisfaction is high over 6 years after A/PSF.

Clinical characteristics of people experiencing biochemical hypoglycaemia during an oral glucose tolerance test: cross-sectional analyses from a UK multi-ethnic population

AIMS

People who experience biochemical hypoglycaemia during an oral glucose tolerance test (OGTT) may be insulin resistant, but this has not been investigated robustly, therefore we examined this in a population-based multi-ethnic UK study.

METHODS

Cross-sectional data from 6478 diabetes-free participants (849 with fasting insulin data available) who had an OGTT in the ADDITION-Leicester screening study (2005-2009) were analysed. People with biochemical hypoglycaemia (2-h glucose <3.3mmol/l) were compared with people with normal glucose tolerance (NGT) or impaired glucose regulation (IGR) using regression methods.

RESULTS

359 participants (5.5%) had biochemical hypoglycaemia, 1079 (16.7%) IGR and 5040 (77.8%) NGT. Biochemical hypoglycaemia was associated with younger age (P<0.01), white European ethnicity (P<0.001), higher HDL cholesterol (P<0.01), higher insulin sensitivity (P<0.05), and lower body mass index (P<0.001), blood pressure (P<0.01), fasting glucose (P<0.001), HbA1C (P<0.01), and triglycerides (P<0.01) compared with NGT and IGR separately in both unadjusted and adjusted (age, sex, ethnicity, body mass index, smoking status) models.

CONCLUSIONS

Biochemical hypoglycaemia during an OGTT in the absence of diabetes or IGR was not associated with insulin resistance, but instead appeared to be associated with more favourable glycaemic risk profiles than IGR and NGT. Thus, clinicians may not need to intervene due to biochemical hypoglycaemia on a 2-h OGTT.

Chronic treatment with a glucagon receptor antagonist lowers glucose and moderately raises circulating glucagon and glucagon-like peptide 1 without severe alpha cell hypertrophy in diet-induced obese mice

AIMS/HYPOTHESIS

Antagonism of the glucagon receptor (GCGR) represents a potential approach for treating diabetes. Cpd-A, a potent and selective GCGR antagonist (GRA) was studied in preclinical models to assess its effects on alpha cells.

METHODS

Studies were conducted with Cpd-A to examine the effects on glucose-lowering efficacy, its effects in combination with a dipeptidyl peptidase-4 (DPP-4) inhibitor, and the extent and reversibility of alpha cell hypertrophy associated with GCGR antagonism in mouse models.

RESULTS

Chronic treatment with Cpd-A resulted in effective and sustained glucose lowering in mouse models in which endogenous murine Gcgr was replaced with human GCGR (hGCGR). Treatment with Cpd-A also led to stable, moderate elevations in both glucagon and glucagon-like peptide 1 (GLP-1) levels, which were completely reversible and not associated with a hyperglycaemic overshoot following termination of treatment. When combined with a DPP-4 inhibitor, Cpd-A led to additional improvement of glycaemic control correlated with elevated active GLP-1 levels after glucose challenge. In contrast to Gcgr-knockout mice in which alpha cell hypertrophy was detected, chronic treatment with Cpd-A in obese hGCGR mice did not result in gross morphological changes in pancreatic tissue.

CONCLUSIONS/INTERPRETATION

A GRA lowered glucose effectively in diabetic models without significant alpha cell hypertrophy during or following chronic treatment. Treatment with a GRA may represent an effective approach for glycaemic control in patients with type 2 diabetes, which could be further enhanced when combined with DPP-4 inhibitors.

Treatment of poxvirus infections in rabbits with 9-beta-D-arabinofuranosyladenine

The antiviral efficacy of 9-beta-d-arabinofuranosyladenine (ara-A) was evaluated in localized lesions produced by the intradermal inoculation of rabbits with vaccinia virus (VV) and rabbit Shope fibroma virus (SFV). Ara-A administered intraperitoneally suppressed or significantly reduced the cutaneous pustular lesions produced by VV as well as the benign skin tumors caused by the SFV. With a daily dose of 300 mg/kg given for 5 days starting at the time of infection, or with 600 mg/kg daily starting 3 days after inoculation, we were able to suppress completely the formation of tumors induced by the SFV. The appearance of pustular lesions induced by VV was completely suppressed by a dose of 600 mg of ara-A per kg given for 3 days when the treatment was initiated at the time of infection, but a significant reduction in the number of pustular lesions was obtained with a single dose of 600 mg/kg, or with five doses of 300 mg/kg starting 24 h after inoculation. No toxic effect of ara-A was noted in the treated rabbits.

Beta(3)-adrenoceptor agonist-induced increases in lipolysis, metabolic rate, facial flushing, and reflex tachycardia in anesthetized rhesus monkeys

The effects of two beta(3)-adrenergic receptor agonists, (R)-4-[4-(3-cyclopentylpropyl)-4,5-dihydro-5-oxo-1H-tetrazol-1-yl]-N-[4-[2-[[2-hydroxy-2-(3-pyridinyl)ethyl]amino]ethyl]phenyl]benzenesulfonamide and (R)-N-[4-[2-[[2-hydroxy-2-(3-pyridinyl)- ethyl]amino]ethyl]phenyl]-1-(4-octylthiazol-2-yl)-5-indolinesulfonamide, on indices of metabolic and cardiovascular function were studied in anesthetized rhesus monkeys. Both compounds are potent and specific agonists at human and rhesus beta(3)-adrenergic receptors. Intravenous administration of either compound produced dose-dependent lipolysis, increase in metabolic rate, peripheral vasodilatation, and tachycardia with no effects on mean arterial pressure. The increase in heart rate in response to either compound was biphasic with an initial rapid component coincident with the evoked peripheral vasodilatation and a second more slowly developing phase contemporaneous with the evoked increase in metabolic rate. Because both compounds exhibited weak binding to and activation of rhesus beta(1)-adrenergic receptors in vitro, it was hypothesized that the increase in heart rate may be reflexogenic in origin and proximally mediated via release of endogenous norepinephrine acting at cardiac beta(1)-adrenergic receptors. This hypothesis was confirmed by determining that beta(3)-adrenergic receptor agonist-evoked tachycardia was attenuated in the presence of propranolol and in ganglion-blocked animals, under which conditions there was no reduction in the evoked vasodilatation, lipolysis, or increase in metabolic rate. It is not certain whether the beta(3)-adrenergic receptor-evoked vasodilatation is a direct effect of compounds at beta(3)-adrenergic receptors in the peripheral vasculature or is secondary to the release or generation of an endogenous vasodilator. Peripheral vasodilatation in response to beta(3)-adrenergic receptor agonist administration was not attenuated in animals administered mepyramine, indomethacin, or calcitonin gene-related peptide(8-37). These findings are consistent with a direct vasodilator effect of beta(3)-adrenergic receptor agonists.

The in vitro fate of rabbit fetal brain cells after acute in vivo hypoxia

In the investigation of ischemia-induced brain damage, traditional methods using histopathology estimate brain cell death at a time remote from ischemic insult. These observations fail to take into account endogenous repair processes or ongoing injury cascades like apoptosis. The cells that are injured but not killed initially are the population most amenable to rescue. The hypothesis was that in vivo uterine ischemia-reperfusion would result in more cell death and apoptosis in fetal brain cells cultured in vitro. Near-term, 29 d gestation, pregnant New Zealand White rabbits were subjected to repetitive uterine ischemia for a cumulative time of 40 min ischemia and 20 min reperfusion. Immediately after uterine ischemia, the fetal brains were removed and dissociated into a cell suspension. The ischemic group had more cell death than non-ischemic controls as assessed by Trypan Blue exclusion and propidium iodide (PI) uptake on a flow cytometer. Aliquots of cells were plated and cultured for 24 and 48 hr. The ischemic group had significantly more cell death (propidium iodide) than non-ischemic controls at 24 hr and significantly more apoptosis, as assessed by annexin-V binding in cells at 24 hr and caspase-3 activity at 48 hr. Fewer cells attached to the culture plates at 48 hr in the ischemia group. After uterine ischemia, certain fetal brain cells die immediately, and other cells undergo ongoing damage resulting in necrosis and apoptosis that is manifest later. This method offers insight into the fate of those cells and provides a tool for assessing interventions to decrease cell injury.

NPS 1506, a moderate affinity uncompetitive NMDA receptor antagonist: preclinical summary and clinical experience

NPS Pharmaceuticals, Inc. (NPS) has synthesized a series of open-channel blockers with varying potencies at the NMDA receptor. NPS 1506 (Fig. 1) is a moderate affinity antagonist that inhibits NMDA/glycine-induced increases in cytosolic calcium in cultured rat cerebellar granule cells (IC50 = 476nM) and displaces the binding of [3H]MK-801 to rat cortical membranes (IC50 = 664nM).

Activation of insulin signal transduction pathway and anti-diabetic activity of small molecule insulin receptor activators

We recently described the identification of a non-peptidyl fungal metabolite (l-783,281, compound 1), which induced activation of human insulin receptor (IR) tyrosine kinase and mediated insulin-like effects in cells, as well as decreased blood glucose levels in murine models of Type 2 diabetes (Zhang, B., Salituro, G., Szalkowski, D., Li, Z., Zhang, Y., Royo, I., Vilella, D., Diez, M. T. , Pelaez, F., Ruby, C., Kendall, R. L., Mao, X., Griffin, P., Calaycay, J., Zierath, J. R., Heck, J. V., Smith, R. G. & Moller, D. E. (1999) Science 284, 974-977). Here we report the characterization of an active analog (compound 2) with enhanced IR kinase activation potency and selectivity over related receptors (insulin-like growth factor I receptor, epidermal growth factor receptor, and platelet-derived growth factor receptor). The IR activators stimulated tyrosine kinase activity of partially purified native IR and recombinant IR tyrosine kinase domain. Administration of the IR activators to mice was associated with increased IR tyrosine kinase activity in liver. In vivo oral treatment with compound 2 resulted in significant glucose lowering in several rodent models of diabetes. In db/db mice, oral administration of compound 2 elicited significant correction of hyperglycemia. In a streptozotocin-induced diabetic mouse model, compound 2 potentiated the glucose-lowering effect of insulin. In normal rats, compound 2 improved oral glucose tolerance with significant reduction in insulin release following glucose challenge. A structurally related inactive analog (compound 3) was not effective on insulin receptor activation or glucose lowering in db/db mice. Thus, small molecule IR activators exert insulin mimetic and sensitizing effects in cells and in animal models of diabetes. These results have implications for the future development of new therapies for diabetes mellitus.

NPS 1506, a novel NMDA receptor antagonist and neuroprotectant. Review of preclinical and clinical studies

NPS 1506 is a moderate affinity, uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist. NPS 1506 is neuroprotective in rodent models of ischemic stroke, hemorrhagic stroke, and head trauma, with a 2-hr window of opportunity. Neuroprotectant doses of NPS 1506 ranged from approximately 0.1-1.0 mg/kg, with peak plasma concentrations ranging from 8-80 ng/mL. Even at doses producing behavioral toxicity, NPS 1506 did not elicit MK-801-like behaviors, did not generalize to phencyclidine (PCP), and did not elicit neuronal vacuolization. In a Phase I study, intravenous (i.v.) doses of NPS 1506 from 5-100 mg were well tolerated and provided plasma concentrations in excess of those required for neuroprotection in rodents. Adverse events at the 100-mg dose included mild dizziness and lightheadedness, and mild to moderate ataxia. Neither PCP-like psychotomimetic effects nor cardiovascular effects were noted. The long plasma half-life of NPS 1506 (approximately 60 hr) suggests that a single i.v. dose will provide prolonged neuroprotection in humans.

Efficacy of a filter device in the prevention of embolic events during carotid angioplasty and stenting: An ex vivo analysis

OBJECTIVE

Although percutaneous angioplasty and stenting (PTAS) of carotid bifurcation lesions is feasible and appropriate for surgically inaccessible lesions, its general role and comparative value remain unclarified. Moreover, the acceptance of carotid PTAS has been limited by its potential for producing embolic debris. This study used an ex vivo model to evaluate the efficacy of a novel filter device to entrap emboli during PTAS of human carotid plaques.

METHODS

Eight carotid bifurcation plaques were obtained from patients who underwent carotid endarterectomy for high-grade atherosclerotic stenosis (>90%). The mean age of the patients was 63 years, and six patients were symptomatic. Each plaque was encased with polytetrafluoroethylene material to simulate adventitia and was connected to a perfusion circuit, which provided continuous flow through the plaque. The filter device consisted of an expandable polymeric membrane with multiple micro pores that was attached to the distal end of a 0.014-in wire with a shapeable tip. This filter was encased in a delivery catheter. With fluoroscopic guidance, the filter wire was passed through the stenosis and the delivery catheter was then retracted to open the filter to capture particles released into the distal internal carotid artery. PTAS with a self-expandable stent then was carried out over the filter wire. The particles released during the initial filter passage, those captured in the filter, and those that flowed through or around the filter (missed) were collected and analyzed with light microscopy.

RESULTS

Filter deployment, PTAS, and filter retrieval were achieved successfully with each lesion. Because the filter has a low crossing profile, it passed through the stenoses smoothly and only produced occasional small particles. PTAS improved the angiographic stenosis from 96.2% +/- 3.7% to 1.3% +/- 1.6%. The mean number and the maximum size of the particles that were released during initial filter passage, missed, and captured by the filter device were 3.1 and 500 microm, 2.8 and 360 microm, 20.1 and 1100 microm, respectively. Most of the particles and those of large size were released during PTAS. The filter captured 88% of these particles.

CONCLUSION

These study results show that this filter device, at least in this model, did not add complexity to the interventional procedure itself. Furthermore, the filter may markedly decrease embolic events during carotid PTAS and expand the indications for this procedure.

Severe peristomal pyoderma gangrenosum: a case study

Pyoderma gangrenosum is an autoimmune disease that often manifests itself as painful ulcers. When these ulcers occur in the peristomal area, symptom management and wound care must be balanced against the need to pouch the stoma. Although the treatment of pyoderma gangrenosum is not standardized, systemic steroid therapy is frequently used as first-line therapy. The WOC nurse is often asked to manage both the pouching needs and topical therapy of the patient with peristomal pyoderma ulcerations. This article describes the management of severe pyoderma gangrenosum ulcerations in a 59-year-old woman with a long-standing ileostomy.

The pharmacokinetics of benazepril relative to other ACE inhibitors

Benazepril is a prodrug that, following rapid conversion to benazeprilat, is a potent nonsulfhydryl inhibitor of angiotensin-converting enzyme. The absorption, bioactivation, distribution, and elimination of benazepril and benazeprilat have been evaluated in healthy subjects, hypertensive patients, and patients with characteristics known to alter the pharmacokinetic disposition of ACE inhibitors, such as renal impairment, hepatic impairment, and advanced age. Following oral administration, benazepril is absorbed and transformed into benazeprilat in the liver. Coadministration of benazepril with food delays absorption slightly but does not affect the ultimate bioavailability of benazeprilat. Severe hepatic impairment slows conversion of benazepril to benazeprilat but does not affect the overall bioavailability of benazeprilat; thus dosage adjustment is not necessary in the hepatically impaired population. Mild-to-moderate renal impairment (creatinine clearance greater than 30 ml/min) slightly increases benazeprilat concentrations; severe renal impairment (creatinine clearance less than 30 ml/min) reduces benazeprilat elimination and requires dosage reduction. In elderly patients, benazepril disposition is the same as in younger patients, although benazeprilat clearance is slightly reduced. No clinically significant drug-drug interactions occur with benazepril and many other medications commonly prescribed to elderly hypertensive patients. The pharmacokinetic characteristics of benazepril are stable over a wide range of conditions, and dosage adjustments for pharmacokinetic reasons are required infrequently.

Design of a selective insulin receptor tyrosine kinase inhibitor and its effect on glucose uptake and metabolism in intact cells

An inhibitor of the insulin receptor tyrosine kinase (IRTK), (hydroxy-2-naphthalenyl-methyl) phosphonic acid, was designed and synthesized and was shown to be an inhibitor of the biological effects of insulin in vitro. With a wheat germ purified human placental insulin receptor preparation, this compound inhibited the insulin-stimulated autophosphorylation of the 95-kDa beta-subunit of the insulin receptor (IC50 = 200 microM). The ability of the kinase to phosphorylate an exogenous peptide substrate, angiotensin II, was also inhibited. Half-maximal inhibition of basal and insulin-stimulated human placental IRTK activity was found at concentrations of 150 and 100 microM, respectively, with 2 mM angiotensin II as the peptide substrate. The inhibitor was found to be specific for tyrosine kinases over serine kinases and noncompetitive with ATP. The inhibitor was converted into various (acyloxy)methyl prodrugs in order to achieve permeability through cell membranes. These prodrugs inhibited insulin-stimulated autophosphorylation of the insulin receptor 95-kDa beta-subunit in intact CHO cells transfected with human insulin receptor. Inhibition of insulin-stimulated glucose oxidation in isolated rat adipocytes and 2-deoxyglucose uptake into CHO cells was observed with these prodrugs. Our data provide additional evidence for the involvement of the insulin receptor tyrosine kinase in the regulation of glucose uptake and metabolism. These results and additional data reported herein suggest that this class of prodrugs and inhibitors will be useful for modulating the activity of a variety of tyrosine kinases.

Acute hemorrhagic cholecystitis causing hemobilia and colonic necrosis

Hemorrhagic cholecystitis is an uncommon cause of hemobilia. A patient with hemorrhagic acalculous cholecystitis and erosion of a hematoma into the colon with fistula formation is reported and operative management is discussed.

Effects of topical applications of phosphonoacetate on colonization of mouse trigeminal ganglia with herpes simplex virus type 1

The effects of topical application of phosphonoacetic acid on the colonization of mouse trigeminal ganglia by herpes simplex virus type 1 were examined. The results showed that the extent of colonization of ganglia by virus is related to the time elapsed between virus inoculation and application of this agent. In most cases, treatment started up to 12 h after inoculation prevented invasion of ganglia by virus. When started up to 24 h after inoculation, treatment reduced and stabilized the amount of virus detectable in trigeminal ganglia during the acute phase of the ganglionic infection. Treatments started 24 h after virus inoculation had little influence on total virus accumulations in trigeminal ganglia. The data also indicate that virus titers in specimens of inoculated and treated skin sites are less affected by topical phosphonoacetic acid treatment than virus titers in ganglia. The experiments may represent a model system for testing effects of other antiviral compounds on colonization of ganglia by virus and may provide some clues regarding the pathogenic mechanism of herpes simplex virus infections.

Effect of acyclovir on latent herpes simplex virus infections in trigeminal ganglia of mice

The inhibition by acyclovir of the in vitro reactivation of herpes simplex virus from latently infected ganglion explant cultures is dependent on the continuous presence of this drug. Administration of acyclovir subcutaneously, orally, or by continuous perfusion to mice with established latent infections did not eliminate latent virus from the trigeminal ganglia.

Experimental skin infection with an acyclovir resistant herpes simplex virus mutant: response to antiviral treatment and protection against reinfection

Skin infections induced in hairless mice with an Acyclovir resistant herpes simplex virus (HSV) mutant were not followed by the death of the animals, and the survivors had no evidence of latent infections in their sensory ganglia. However, mutant virus was detected in the ganglia during the acute phase of the infection. Mice inoculated with the mutant were fully protected against the fatal outcome of the infection when subsequently challenged with the relatively pathogenic parental virus. In addition the frequency of latent infections established after challenge was significantly reduced. Phosphonoacetic acid treatment of the primary mutant-induced infection abolished the protection against reinfection with parental virus. Acyclovir treatment of the primary infection with the mutant virus did not affect the protection against reinfection with parental virus. The results indicate that drug-resistant, latency-negative, HSV mutants are a promising starting point for the development of an attenuated HSV vaccine.

Latent infections of sensory ganglia as influenced by phosphonoformate treatment of herpes simplex virus-induced skin infections in hairless mice

Topical treatment with 3% phosphonoformate of herpes simplex virus type 1 (HSV)-induced skin infections of hairless mice reduced the severity of skin lesions when the treatment was initiated 3 h after virus inoculation in the lumbosacral area or 3 and 24 h after inoculation in the orofacial area. The mortality was significantly reduced in lumbosacral-infected mice and was completely prevented in orofacial-infected mice when the treatment was initiated with a delay of 24 h after virus inoculation. However, phosphonoformate did not prevent the establishment of latent herpes simplex virus type 1 infections in the spinal and trigeminal ganglia, even when treatment was initiated as early as 3 h after infection.

Latent herpes simplex virus in ganglia of mice after primary infection and reinoculation at a distant site

Herpes simplex virus (HSV)-infected hairless mice with evidence of latent infection in spinal ganglia did not develop latent HSV infections in trigeminal ganglia upon reinfection in the oro-facial area. HSV-infected and PAA-treated mice without evidence of latent HSV infection in spinal ganglia were resistant to reinfection in the lumbar region, but not to that performed in the oro-facial area.

Immunoglobulin content and antibody activity in an artificial body cavity

Artificial body cavities (ABC) were created by the insertion of hollow polyethylene balls in the subcutaneous tissue of rabbits. After two months no inflammatory reaction could be detected, the ABC was enveloped by a membranous structure, and the cavity contained about 20 ml of fluid. The protein concentration was about 3 times, and the IgG about 8 times, lower in the ABC fluids than in the corresponding serum. At the same time the antibody titers against sheep red blood cells (SRBC), human IgG and herpes simplex virus type 1 (HSV) were about 20 200 times lower than in the corresponding serum samples. The IgG molecules appeared to be undamaged as shown by the presence of various allotypes and by the elution pattern from G-200 column. Testing the protective activity of ABC fluids and of serum against HSV infection showed that ABC fluids had no protective activity. The experiments suggest that the membranous structure selected among classes of Ig and probably among other serum proteins. In addition, the IgG molecules with antibody activity against various inoculated antigens were selectively excluded to penetrate in the ABC. The ABC might be considered analogous to virtual cavities of the body surrounded by membranes and possibly to the extravascular compartment.

Herpes simplex virus skin infection in hairless mice: treatment with antiviral compounds

A hairless mouse-herpes simplex virus skin infection experimental model was used to evaluate the efficacy of the antiviral compounds 9-beta-d-arabinofuranosyladenine (ara-A), 5-iodo-2'-deoxyuridine (IUdR), and 6-azauridine (aza-U). Ara-A and IUdR, when administered intraperitoneally by several different dosage schedules, reduced the severity of cutaneous herpetic lesions and the incidence of paralysis and increased significantly the number of survivors. A more rapid healing of the lesions and an increase in the mean survival time also was observed. A delay of 24 to 48 h in the initiation of treatment after the infection was more effective than treatments started at the time of inoculation. Treatment with ara-A was somewhat superior to that with IUdR, but aza-U was totally ineffective. Enhancement of the evolution of the infection was noted after treatment with aza-U.