First Measurement of Near-Threshold J/ψ Exclusive Photoproduction off the Proton

We report on the measurement of the γp→J/ψp cross section from E_{γ}=11.8  GeV down to the threshold at 8.2 GeV using a tagged photon beam with the GlueX experiment. We find that the total cross section falls toward the threshold less steeply than expected from two-gluon exchange models. The differential cross section dσ/dt has an exponential slope of 1.67±0.39  GeV^{-2} at 10.7 GeV average energy. The LHCb pentaquark candidates P_{c}^{+} can be produced in the s channel of this reaction. We see no evidence for them and set model-dependent upper limits on their branching fractions B(P_{c}^{+}→J/ψp) and cross sections σ(γp→P_{c}^{+})×B(P_{c}^{+}→J/ψp).

A perspective on global access to insulin: a descriptive study of the market, trade flows and prices

AIM

To describe the global insulin market.

METHODS

Market intelligence data, United Nations Commodity Trade Statistics for insulin trade, the International Medical Products Price Guide for prices of human insulin and additional web searches were used as data sources. These sources were combined to gain further insight into possible links among market, trade flows and prices. Descriptive statistics and Spearman's rank order correlation were used for the analysis.

RESULTS

A total of 34 insulin manufacturers were identified. Most countries and territories are reliant on a limited number of supplying countries. The overall median (interquartile range) government procurement price for a 10-ml, 100-IU/ml vial during the period 1996-2013 equivalent was US$4.3 (US$ 3.8-4.8), with median prices in Africa (US$ 4.7) and low- (US$ 6.9) and low- to middle- (US$ 4.7) income countries being higher over this period. The relationships between price and quantity of insulin (Spearman's r=0.046; P>0.1) and number of import links (Spearman's r=0.032; P>0.1) were weak. The links between price and percentage of total insulin from a country where a 'big three' manufacturer produces insulin (Spearman's r=0.294; P<0.05) and total insulin from the main import link (Spearman's r=-0.392; P<0.05) were stronger.

CONCLUSIONS

This research shows the high variability of insulin prices and the reliance on a few sources, both companies and countries, for global supply. In addressing access to insulin, countries need to use existing price data to negotiate prices, and mechanisms need to be developed to foster competition and security of supply of insulin, given the limited number of truly global producers.

High-intensity functional training improves functional movement and body composition among cancer survivors: a pilot study

This pilot study investigated feasibility and preliminary efficacy of a high-intensity functional training (HIFT) group-exercise programme among adult cancer survivors within 5 years of last cancer treatment. Eight participants were assigned to a 5-week, 3 days/week HIFT intervention with four testing sessions and 12 workouts along with mobility and stretching exercises. Feasibility was assessed by initiation, adherence, and acceptability. Efficacy was determined by changes from baseline to post-test in health-related quality of life, body composition and functional movement. The recruitment rate was 80% and the adherence rate was 75%. Significant improvements were found for emotional functioning (P = 0.042) and body composition (lean mass +3.8 ± 2.1 kg, P = 0.008; fat mass -3.3 ± 1.0 kg, P = 0.001; body fat percentage -4.7 ± 1.2%, P < 0.001). Participants also significantly improved on five of seven functional movements: balance (P = 0.032), carrying a weighted object (P = 0.004), lower body strength and power (P = 0.009), aerobic capacity and endurance (P = 0.039), and perceived difficulty for flexibility (P = 0.012). Five weeks of HIFT training was well-received and feasible for most cancer survivors, and effective for improving emotional functioning, body composition and functional movement.

Abstract C26: A phase 1 multiple ascending dose study of cabozantinib (XL184) monotherapy in Japanese patients with advanced solid tumors

Background: Cabozantinib is a potent orally available small molecule inhibitor of multiple receptor tyrosine kinases with growth promoting and angiogenic properties. The primary targets of cabozantinib are MET and VEGFR2. In preclinical models, cabozantinib demonstrated significant tumor growth inhibition in multiple tumor models including human medullary thyroid cancer (MTC), human breast cancer, human lung carcinoma and rat glioblastoma. Anti-tumor activity in patients has been observed across a broad range of tumor types including MTC, prostate, ovarian and breast cancer, non-small cell lung cancer (NSCLC), hepatocellular carcinoma, melanoma and glioblastoma. The primary objectives of this open-label phase 1 study are determination of the maximum tolerated dose (MTD) and recommended phase 2 dose in Japanese patients.

Methods: Patients with advanced solid malignancies are enrolled in successive cohorts to receive escalating doses of cabozantinib in a 3+3 trial design. Patients are treated with continuous 4-week cycles of cabozantinib administered orally (PO) once daily (QD). Dose limiting toxicities (DLTs) are determined using Cycle 1 data. Response is assessed on Day 29 and every 8 weeks thereafter by modified RECIST v1.0 criteria and patients with stable disease (SD) or objective response receive continued therapy. Pharmacokinetic (PK) parameters of cabozantinib and relevant plasma markers including VEGF-A, sVEGFR2 and PlGF are being evaluated.

Results: As of 1 September 2011, 6 patients with advanced malignancies have been enrolled: NSCLC (n=3), colorectal cancer, gastrointestinal stromal tumor (GIST), leiomyosarcoma (n=1 each). Patients were pretreated with a median of 3 prior regimens (range, 2 − 7). Patients have been treated at 2 dose levels of 40mg and 60mg free base equivalents (salt strengths of 50mg and 75mg, respectively) PO QD. There have been no DLTs or serious adverse events reported to date. The MTD has not yet been defined. Observed adverse events were generally mild to moderate and include hypertension, palmer-plantar erythrodysesthesia, diarrhea, mucositis, rash, edema and headache. Laboratory abnormalities include elevated AST/ALT, neutropenia, thrombocytopenia and increases in alkaline phosphatase, LDH, lipase and TSH. Results of preliminary PK analysis at the 40mg QD dose level showed that cabozantinib appeared to reach steady-state plasma concentrations by Day 15 and there was evidence of 6- to 7-fold accumulation on Day 19. One patient with NSCLC has had a confirmed partial response with 38% reduction in the sum of target lesions. Three pretreated patients including 2 with NSCLC and 1 with GIST have had SD with reductions in the sum of target lesions of 20, 13 and 16% respectively, and continue treatment with cabozantinib.

Conclusions: Cabozantinib appears well tolerated at doses tested to date. Early signs of antitumor activity including prolonged stable disease and response have been observed in the initial dosing cohorts. Determination of the MTD is ongoing.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C26.

Anastomotic leakage after resection of colorectal cancer generates prodigious use of hospital resources

OBJECTIVE

The aim of this study was to determine the demand for hospital resources generated by anastomotic leakage, including surgical, medical, imaging, pathology, and other allied health consultations or services and length of postoperative hospital stay.

METHOD

Data were obtained from a comprehensive, prospective hospital registry of all resections for colorectal cancer from January 1995 to December 2004 and from retrospective review of patients' notes.

RESULTS

Forty-one patients with a leak spent 92 days in intensive care, required 129 days of total parenteral nutrition, 69 days of enteric feeding and 41 days on ventilation and had a median postoperative hospital stay of 28 days (range 11-104). These patients required 24 re-operations and 2273 separate medical consultations or allied services.

CONCLUSION

Anastomotic leakage generates a very considerable demand for hospital resources and diverts these resources from the hospital population at large.

Inhalation efficacy of RFI-641 in an African green monkey model of RSV infection

Human respiratory syncytial virus (RSV) is a major cause of acute upper and lower respiratory tract infections. RFI-641 is a novel RSV fusion inhibitor with potent in vitro activity. In vivo efficacy of RFI was determined in an African green monkey model of RSV infection involving prophylactic and therapeutic administration by inhalation exposure. Inhalation was with an RFI-641 nebulizer reservoir concentration of 15 mg/ml for 15 minutes (short exposure) or 2 hours (long exposure). Efficacy and RFI-641 exposure was determined by collection of throat swabs, nasal washes and bronchial alveolar lavage (BAL) on selected days. The short-exposure group (15 minutes) exhibited no effect on the nasal, throat or BAL samples. The throat and nasal samples for the long-exposure group failed to show a consistent reduction in viral titers. RFI-641 2 hours exposure-treated monkeys showed a statistically significantly log reduction for BAL samples of 0.73-1.34 PFU/ml (P-value 0.003) over all the sampling days. Analysis indicates that the long-exposure group titer was lower than the control titer on day 7 and when averaged across days. The results of this study demonstrate the ability of RFI-641 to reduce the viral load of RSV after inhalation exposure in the primate model of respiratory infection.

Nutritional and immune status following spinal cord injury: a case controlled study

STUDY DESIGN

Case controlled study.

OBJECTIVE

To compare nutritional status and immune response in a group of spinal cord injured (SCI) patients with age and gender matched non SCI control subjects.

METHOD

Thirty past patients of the Burwood Hospital Spinal Injuries Unit living locally were enrolled in the study. Age and gender matched non SCI control subjects were selected volunteers from hospital staff. Nutritional status was assessed by generating a Nutritional Risk Score (NRS, Appendix 1) and drawing blood for full blood count, iron studies, red blood cell folate, vitamin B12, ferritin, magnesium, and zinc. Immune status was assessed by vaccination response index (VRI) to Pneumovax 23 vaccine.

RESULTS

Full blood count, iron studies, and testing for red blood cell folate, albumin, prealbumin, vitamin B12, ferritin, magnesium and zinc were normal range for both groups. The SCI group had significantly different median values than controls (P < 0.01) for haemoglobin concentration, white blood cell count, albumin, prealbumin, serum iron and % saturation. Body Mass Index (weight kg/(height cm(2)) was 22.2 (range 15-30) for the SCI group, significantly less than the paired control group index of 26 (range 20-32, P = 0.0004). Median NRS for SCI patients was 2 (range 0-6), compared to 0 (range 2-4) for paired controls (P < 0.0001). Scores ranged from 0 to 2 for each of the five NRS components for the SCI patients and 0 to 3 for the control group. There was no significant difference in the pre- and post-vaccination ratio for IgG, IgA, and IgM response to Pneumovax 23 vaccine.

CONCLUSION

We have not identified any nutritional or immune status abnormality in SCI patients, however the SCI patients have a lower value for certain nutritional parameters and BMI. SCI patients however are at only slight risk of nutritional problems given their NRS and their lower normal values for certain nutritional factors.

New opportunities for high-resolution solid-state NMR spectroscopy of oxide materials at 21.1- and 18.8-T fields

We present here high-resolution solid state NMR spectra of several oxide and silicate materials that illustrate the improvements obtainable with very high external fields (18.8 and 21.1 T), with probes capable of tuning to a wide frequency range that allow observations of nuclides from high to low magnetogyric ratio. We discuss 27Al MAS spectra for the zeolite scolecite (CaAl2Si3O10 x 3H2O), 17O MAS data for analcime (NaAlSi2O6 x H2O), calcium monoaluminate (CaAI2O4), and titanite (CaTiSiO5), 39K spin-echo spectra for leucite (KAlSi2O6), microline (KAlSiO8), muscovite (KAl2(AlSi3O10)(OH2) and a potassium aluminosolicate glass, and preliminary 73Ge spin-echo MAS spectra for crystalline and glassy germanium dioxide (GeO2).

Cerebral cell adhesion molecule: a novel leukocyte adhesion determinant on blood-brain barrier capillary endothelium

The tight junctions of the cerebral capillary endothelium form the highly restrictive blood-brain barrier. Migration of leukocytes across this unique barrier may involve ligation of elements in addition to those of the fenestrated capillaries of the peripheral vascular system. An antibody raised against a bacterial adhesive protein and shown to have cross-reactivity with brain capillaries and to block leukocyte migration into the brain was used to identify and clone a novel determinant on brain microvessels. This cDNA was sequenced, and the expressed protein supported leukocyte adhesion in a CD18-dependent fashion. The high level of brain microvessel expression of this adhesion molecule, termed the cerebral cell adhesion molecule, implicates it in leukocyte transmigration across the blood-brain barrier.

FITC-poly-D-lysine conjugates as fluorescent probes to quantify hapten-specific macrophage receptor binding and uptake kinetics

A series of fluorescein derivatized poly-D-lysine (FITC-PDL) probes were used to elucidate the role of fluorescein in receptor binding of fluorescein-conjugated macromolecules to J774 murine macrophages. Poly-D-lysine served to eliminate receptor recognition of the carrier due to the biologically inert nature of the D-isomer. This concept enabled the focused investigation of the role played by fluorescein in receptor recognition, binding and internalization. Results revealed dependency of cellular uptake on polymer concentration, hapten density and accessibility. The results differed from those previously obtained with FITC-BSA in that saturating fluorescein densities on the poly-D-lysine polymer resulted in diminished rates of uptake by macrophages. Receptor-mediated endocytosis via clathrin-coated pits was concluded based on results that showed inhibition of FITC-PDL uptake by intracellular K+ depletion but not by the macropinocytosis inhibitor, amiloride. Further, FITC-PDL was found to inhibit the endocytic uptake of FITC-BSA suggesting competition between the two probes at the level of a macrophage receptor. Association rates (kon) for binding to the macrophage surface were measured for the various FITC-PDL probes based on fractional receptor occupancies. Results are discussed on the basis of receptor recognition of fluorescein in J774 macrophages and the requirements for this recognition which include appropriate spacing and accessibility of the hapten moieties to facilitate receptor crosslinking.

Homeopathy in office practice

Homeopathy is widely used around the world and is regaining popularity in the United States where it enjoyed popular and therapeutic success in the 1800s. Relying on systematic principles of health and disease first set forth by Samuel Hahnemann in 1810, it offers a powerful and inexpensive means of promoting self-care and of augmenting therapeutic options for the family physician. History, theory and practical considerations are reviewed.

Transforming growth factor-beta expression in macrophages during hypercholesterolemic states

Macrophage infiltration into the glomerular mesangium is a prominent feature of various glomerulopathies. Recent evidence suggests that infiltrating macrophages may play a role in propagating initial glomerular injury to the development of glomerulosclerosis via transforming growth factor-beta (TGF-beta)-stimulating matrix accumulation. Rats with the acute puromycin aminonucleoside (PA) nephrosis exhibit an elevated gene expression of glomerular TGF-beta 1; however, the cellular origin of this upregulation is unknown. Using polymerase chain reaction (PCR), we detected that the TGF-beta 1 isoform is expressed in glomerular macrophages isolated from experimental rats made hypercholesterolemic by either diet or by induction of PA nephrosis. Peritoneal macrophages from nephrotic or dietary-hypercholesterolemic animals also exhibited a significant increment in the expression of TGF-beta 1 mRNA on Northern analysis, in contrast to similar cells obtained from normal control rats. PCR analysis of glomerular RNA also detected the expression of the TGF-beta 2 mRNA isoform. TGF-beta 2 mRNA expression was not observed in isolated glomerular macrophages from either glomeruli of PA-nephrotic rats or from glomeruli of animals with dietary hypercholesterolemia. Expression of the TGF-beta 3 mRNA isoform was only observed by PCR in J774 A.1 cells. Thus the as a cellular source for the enhanced expression of TGF-beta 1 during the acute nephrotic phase of our toxic, progressive glomerulopathy model and within several days of inducing only hypercholesterolemia by dietary means.

The incidence of spontaneous subarachnoid hemorrhage with change in barometric pressure

The authors' observation of an apparent increased incidence of patients presenting with spontaneous subarachnoid hemorrhage (SAH) during stormy weather prompted them to retrospectively review admissions data during an 18-month period to look for an association between SAH and changes in barometric pressure (BMP). Of the 39,049 cases examined, 76 had confirmed SAH. Continuous graphs of BMP were used to categorize days as being "flat" days (change in BMP < or = 0.15; dpHg) or "change" days (change in BMP > 0.15; dpHg). Days on which patients presented with SAH were significantly correlated with change days (P < .004). There was significantly more SAH during the winter months (October to March), than during the remaining summer months (P < .02). The correlation of SAH with change in BMP did not hold if these summer months were examined alone. The risk ratio of having an SAH on an inclement day during the winter months was 1.99 (95% confidence interval, 1.11 to 3.60). The reason for this association is not clear at this time.

Macrophages mediate adverse effects of cholesterol feeding in experimental nephrosis

We tested whether the deleterious effects of hypercholesterolemia, in a progressive glomerular disease model, may be mediated by infiltrating renal macrophages. A single sublethal dose of whole body X-irradiation (XI) delivered to rats with acute puromycin aminonucleoside (PA) nephrosis fed a high-cholesterol (HC) diet resulted in significantly greater inulin and p-aminohippurate (PAH) clearances at 11 days after PA without any alterations in circulating lipid levels, in contrast to nonirradiated HC-fed nephrotic controls. This functional protection was associated with significant declines in both glomerular and cortical interstitial macrophage number. Over the course of this 16-wk model, HC-fed PA rats had significantly less albuminuria as well as significantly fewer glomerulosclerosis (GS) lesions and less mesangial matrix expansion at the end of the study despite an equivalent degree of sustained hypercholesterolemia. This data suggests that reducing the infiltrating glomerular and cortical interstitial macrophage burden with XI during acute PA nephrosis, unaccompanied by any hypolipidemic effect, produces not only early salutary effects on renal function but also a significant amelioration of the progressive glomerulopathic features of this model. This is consistent with the hypothesis that the infiltrating renal macrophage, in large part, directly mediates the adverse effects of hypercholesterolemia in this model.

Glomerular macrophages and the mesangial proliferative response in the experimental nephrotic syndrome

Mesangial cell proliferation, which is a harbinger of glomerulosclerosis, occurs in both immune and nonimmune glomerulopathies. The proximity of infiltrating glomerular macrophages to the contractile mesangial cells during acute puromycin aminonucleoside (PA) nephrosis suggests the possibility of a paracrine effect on mesangial cell growth. To test this, three maneuvers to either raise or lower the glomerular macrophage number during acute PA nephrosis (2 weeks after PA) were employed: 1) an essential fatty acid-deficient (EFAD) diet; 2) a cholesterol-supplemented diet (CSD); and 3) a single dose (600 rad) whole-body X-irradiation (XI) given to CSD-fed PA rats. Both the glomerular macrophage number and proliferation within the mesangium were evaluated immunohistochemically with ED-1, a mouse monoclonal anti-rat macrophage label, and 19A2, a mouse monoclonal anti-proliferating cell nuclear antigen (PCNA)/cyclin antibody, respectively. Immunohistochemical detection of 5'-bromo-2'-deoxyuridine (BrdU) incorporation confirmed that proliferation was occurring within the mesangial zones. The EFAD diet significantly reduced both the glomerular macrophage and PCNA/cyclin-positive cell number at 2 weeks after PA with a positive correlation (r = 0.89, P < 0.05). The CSD maneuver significantly increased both the glomerular macrophage and PCNA/cyclin cell number with a strong degree of correlation (r = 0.95, P < 0.01). X-irradiation administered to CSD-fed PA rats significantly lowered both the glomerular macrophage and PCNA/cyclin-positive cell number at 2 weeks. In all groups, the glomerular tufts did not express muscle actin using HHF 35, a specific immunolabel, suggesting that the proliferation in this model is not related to direct mesangial cell injury. This study shows that maneuvers that modulate the glomerular macrophage number are also associated with corresponding changes in the number of proliferating cells within the mesangium, suggesting a paracrine growth stimulation by the infiltrating macrophage during acute PA nephrosis. The infiltrating glomerular macrophage may be an effector mechanism for the propagation of initial glomerular injury to glomerulosclerosis by augmenting mesangial cell proliferation early in the course of this nonimmune progressive glomerulopathy.

Progressive albuminuria and glomerulosclerosis in a rat model of chronic renal allograft rejection

A significant proportion of renal allografts fail within several months or years after transplantation, primarily because of chronic rejection. The etiology and pathophysiology of this condition remain unclear. We studied the renal function, morphology, and immunohistology, in parallel, among F344-to-Lewis allografts (n = 23) and isografts (n = 13) over the course of 24 weeks. Only an initial 10-day course of CsA (5 mg/kg/day) was given to both groups to prevent acute rejection. Hypertension did not develop, although awake systolic blood pressure was significantly higher in allografts at the end of the study. Significant differences in urine albumin excretion (UalbV) between isografts and allografts were evident as early as 4 weeks after engraftment but rose dramatically by 20 weeks (3.3 +/- 0.7 vs. 21.2 +/- 3.7 mg/day, respectively, P < .001). This pattern continued until the conclusion of the study (5.0 +/- 1.1 vs. 53.5 +/- 7.6 mg/day, P < .001). Serum creatinine values were only significantly elevated in allografts at 16 weeks, which temporally corresponded to the dramatic increase in UalbV. However, renal blood flow and glomerular filtration rate, measured by paraaminohippurate and inulin clearances, respectively, were significantly lower in allografted organs, at 24 weeks. The frequency of glomerulosclerosis lesions was significantly increased in allografted kidneys at 24 weeks and correlated with UalbV values. Glomerular localization of mononuclear leukocyte subsets were equivalent between allografts and isografts; however, the numbers of interstitial macrophages, CD8+, and pan-T-cells were all significantly greater in allografts at 24 weeks. The infiltration of significantly greater numbers of macrophages and lymphocytes into the tubulointerstitium of the allograft group suggests a mononuclear leukocyte effector cell mediation of the progressive glomerular abnormalities in this model of chronic renal allograft rejection in the rat.

Root aeration in wetland trees by pressurized gas transport

Tracer gas studies and oxygen uptake measurements have shown that pressurized gas transport improves oxygen supply to roots in the wetland tree species Taxodium distichum L. Rich. (Taxodiaceae), Betula pubescens J.F. Ehrh. (Betulaceae), and Populus tremula L. (Salicaceae), but not in Acer pseudoplatanus L. and Ilex aquifolium L., which are found in drier habitats. In the deciduous tree species Betula pubescens and Populus tremula, pressurized gas transport was most evident during the resting period, which is characterized by soil anoxia following waterlogging of the natural habitat. Because pressurized gas transport is found in species of distantly related families, we hypothesize that it helps wetland species survive the initial period of soil flooding before acclimation to waterlogging cccurs.

Cholesterol dynamics in membranes

Time-resolved fluorescence anisotropy of the sterol analogue, cholestatrienol, and 13C nuclear magnetic resonance (NMR) spin lattice relaxation time (T1c) measurements of [13C4] labeled cholesterol were exploited to determine the correlation times characterizing the major modes of motion of cholesterol in unsonicated phospholipid multilamellar liposomes. Two modes of motion were found to be important: (a) rotational diffusion and (b) time dependence of the orientation of the director for axial diffusion, or "wobble." From the time-resolved fluorescence anisotropy decays of cholestatrienol in egg phosphatidylcholine (PC) bilayers, a value for tau perpendicular, the correlation time for wobble, of 0.9 x 10(-9) s and a value for S perpendicular, the order parameter characterizing the same motion, of 0.45 s were calculated. Both tau perpendicular and S perpendicular were relatively insensitive to temperature and cholesterol content of the membranes. The T1c measurements of [13C4] labeled cholesterol did not provide a quantitative determination of tau parallel, the correlation time for axial diffusion. T1c from the lipid hydrocarbon chains suggested a value for tau perpendicular similar to that for cholesterol. Steady-state anisotropy measurements and time-resolved anisotropy measurements of cholestatrienol were used to probe sterol behavior in a variety of pure and mixed lipid multilamellar liposomes. Both the lipid headgroups and the lipid hydrocarbons chains contributed to the determination of the sterol environment in the membrane, as revealed by these fluorescence measurements. In particular, effects of the phosphatidylethanolamine (PE) headgroup and of multiple unsaturation in the lipid hydrocarbon chains were observed. However, while the steady-state anisotropy was sensitive to these factors, the time-resolved fluorescence analysis indicated that tau perpendicular was not strongly affected by the lipid composition of the membrane. S perpendicular may be increased by the presence of PE. Both steady-state anisotropy measurements and time-resolved anisotropy measurements of cholestatrienol were used to probe sterol behavior in three biological membranes: bovine rod outer segment (ROS) disk membranes, human erythrocyte plasma membranes, and light rabbit muscle sarcoplasmic reticulum membranes. In the ROS disk membranes the value for S perpendicular was marginally higher than in the PC membranes, perhaps reflecting the influence of PE. The dramatic difference noted was in the value for tau perpendicular. In both the ROS disk membranes and the erythrocyte membranes, tau perpendicular was one-third to one-fifth of tau perpendicular in the phospholipid bilayers. This result may reveal an influence of membrane proteins on sterol behavior.

Phosphorylation modulates keratin structure

Bovine hoof keratin was shown to be a substrate for cAMP-dependent protein kinase using [gamma-32P]ATP. Natural-abundance cross-polarization (CP) MAS 13C NMR was used to examine the effect of phosphorylation on keratin structure. When short contact times were used, phosphorylation was shown to increase the number of residues in the motionally restricted portions of the protein; i.e., a portion(s) of the protein became more rigid upon phosphorylation. Circular dichroism (CD) spectra showed a spectral shape characteristic of alpha helix for this keratin. Phosphorylation of the keratin by cAMP-dependent protein kinase resulted in a CD spectrum with the same shape but of greater apparent intensity. This may have been the result of an increase in the alpha-helical content of the protein. These data showed that the structure of keratin changed significantly upon phosphorylation by cAMP-dependent protein kinase. The region of the keratin molecule most likely to be altering its structure was the end of the molecule, which was involved in the formation of, and intracellular attachment of, intermediate filaments. Therefore, these data suggested that cAMP-dependent phosphorylation may produce significant changes in the intracellular organization of intermediate filaments. When the keratin was phosphorylated using cold ATP, magic-angle spinning (MAS) 31P nuclear magnetic resonance (NMR) revealed two resonances arising from the phosphorylation sites on the keratin. The more shielded resonance was shown to arise from cAMP-dependent protein kinase phosphorylation. Static 31P NMR measurements suggested that at least two classes of cAMP-dependent sites existed with the same isotropic 31P chemical shift; one was considerably motionally restricted with respect to the other.

Effects of unsaturation on 2H-NMR quadrupole splittings and 13C-NMR relaxation in phospholipid bilayers

Motional order and motional rates in unsonicated phospholipid bilayers were assessed as a function of unsaturation of the phospholipid. A measurement sensitive to motional order was obtained using 2H-NMR of 18:1, 18:1-phosphatidylcholine labelled at positions 9 and 10 with deuterium and included as a probe in phospholipid bilayers of interest at 10 mole percent. Spin lattice relaxation times from magic angle spinning 13C-NMR spectra of phospholipid dispersions of interest were used as a measure of motional rates. Measurements were made of phospholipid bilayers containing from 0 to 8 double bonds per molecule. No large effect of an increase in unsaturation was noted for the 2H-NMR quadrupole splittings or for the 13C-NMR spin lattice relaxation rate.

Cross polarization P-31 nuclear magnetic resonance of phospholipids

P-31 single-pulse and cross-polarization (CP) nuclear magnetic resonance spectra were obtained of aqueous dispersions of pure phospholipids. Dimyristoyl phosphatidylcholine, dipalmitoylphosphatidylcholine, 1-palmitoyl-2-oleoyl phosphatidylcholine, egg phosphatidylcholine, bovine brain sphingomyelin, and transphosphatidylated (from egg phosphatidylcholine) phosphatidylethanolamine were studied. The spectra from all the phospholipids, taken in the usual single-pulse mode, showed the pseudo-axially symmetric powder pattern typical of phospholipids in a hydrated lamellar form. P-31 CP spectra of all the phosphatidylcholines and phosphatidylethanolamine revealed a decrease in intensity in the vicinity of the isotropic chemical shift as long as the lipid was above the gel-to-liquid crystalline phase transition temperature. This intensity pattern has been observed previously for C-13 CP spectra of molecules rotating rapidly about a single well-defined axis (e.g., solid benzene) (Pines, A., M.G. Gibby, and J.S. Waugh, 1973, J. Chem. Phys., 59:569-590). Pure lipid dispersions below their gel-to-liquid crystalline phase transition temperature, including dipalmitoylphosphatidylcholine and sphingomyelin, do not exhibit a local minimum in the CP spectrum at the position of the isotropic chemical shift. Thus, below the phase transition temperature, there is not the same rapid rotation of the headgroup about a well-defined axis. A dramatic change in the rate of headgroup rotation is shown to take place at the pretransition of dipalmitoylphosphatidylcholine. P-31 CP spectra were also obtained for bovine rod outer segment disk membranes, rabbit muscle sarcoplasmic reticulum membranes, a total lipid extract of the latter, and a recombined membrane containing human erythrocyte glycophorin. The CP spectra were similar to the single-pulse spectra, indicating a substantial difference in behavior from pure phospholipid dispersions. This is interpreted in terms of a slower headgroup rotation.

Analysis of solid-state Carbon-13 NMR spectra of polymorphs (benoxaprofen and nabilone) and pseudopolymorphs (cefazolin)

The solid-state 13C-NMR spectra of the polymorphs of benoxaprofen, nabilone, and cefazolin are reported using the cross-polarization/magic-angle spinning (CP/MAS) technique. In general, the spectra of the different crystal forms are different. In favorable cases the spectra of the drug in a pharmaceutical granulation can be discerned. These results provide a preliminary indication that solid-state NMR spectroscopy is a useful technique for the investigation of drug polymorphs and drugs in their dosage forms.

The role of plasma lipids in carotid bifurcation atherosclerosis

The severity of coronary artery atherosclerosis correlates with increased plasma concentrations of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides and with decreased plasma concentrations of high-density lipoprotein cholesterol (HDL-C). The role of plasma lipoproteins in the pathogenesis of cerebral atherosclerosis, however, is less clear. Several investigators report that lipoprotein abnormalities correlate inversely with the incidence of cerebral infarction. We analyzed risk factors for carotid bifurcation atherosclerosis in 121 consecutive patients who underwent cerebral angiography. This analysis revealed a significant positive correlation between the plasma TC/HDL-C ratio and the extent of carotid bifurcation atherosclerosis (p = 0.01). The extent of atherosclerosis correlated inversely with plasma concentrations of HDL-C (p = 0.02). Triglyceride concentration correlated positively with the extent of atherosclerosis with marginal significance (p = 0.07). LDL-C and TC concentrations did not correlate with bifurcation atherosclerosis (p greater than 0.1). Only 4% of the variation in the extent of bifurcation atherosclerosis was explicable on the basis of plasma lipoprotein concentrations.

Changes in surface morphology of Chinese hamster ovary cells during the cell cycle

Synchronized populations of Chinese hamster ovary (CHO) cells in confluent culture have been examined by scanning electron microscopy and their surface changes noted as the cells progress through the cycle. During G(1) it is characteristic for cells to show large numbers of microvilli, blebs, and ruffles. Except for the ruffles, these tend to diminish in prominence during S and the cells become relatively smooth as they spread thinly over the substrate. During G(2) microvilli increase in number and the cells thicken in anticipation of rounding up for mitosis. It appears that the changes observed here reflect the changing capacity of CHO cells during the cycle to respond to contact with other cells in the population, because, as noted in the succeeding paper (Rubin and Everhart), CHO cells in sparse nonconfluent cultures do not show the same wide range of changes during the cell cycle. Normal, nontransformed cells of equivalent type in confluent culture are essentially devoid of microvilli, blebs, and ruffles. The relation of these surface configurations to the internal structure of the cell is discussed.