Observation and properties of the X(3872) decaying to J/psipi(+)pi(-) in pp collisions at sqrt[s]=1.96 TeV

We report the observation of the X(3872) in the J/psipi(+)pi(-) channel, with J/psi decaying to mu(+)mu(-), in pp collisions at sqrt[s]=1.96 TeV. Using approximately 230 pb(-1) of data collected with the Run II D0 detector, we observe 522+/-100 X(3872) candidates. The mass difference between the X(3872) state and the J/psi is measured to be 774.9+/-3.1(stat)+/-3.0(syst) MeV/c(2). We have investigated the production and decay characteristics of the X(3872) and find them to be similar to those of the psi(2S) state.

Search for doubly charged higgs boson pair production in the decay to mu(+)mu(+)mu(-)mu(-) in pp collisions at sqrt[s]=1.96 TeV

A search for pair production of doubly charged Higgs bosons in the process pp -->H(++)H(--) -->mu(+)mu(+)mu(-)mu(-) is performed with the D0 run II detector at the Fermilab Tevatron. The analysis is based on a sample of inclusive dimuon data collected at an energy of sqrt[s]=1.96 TeV, corresponding to an integrated luminosity of 113 pb(-1). In the absence of a signal, 95% confidence level mass limits of M(H(+/-+/-)(L))>118.4 GeV/c(2) and M(H(+/-+/-)(R))>98.2 GeV/c(2) are set for left-handed and right-handed doubly charged Higgs bosons, respectively, assuming 100% branching into muon pairs.

Injuries in youth amateur soccer and rugby players--comparison of incidence and characteristics

OBJECTIVES

In reviewing the literature on sports injuries, few studies could be found in which exposure related incidences of injury in different types of sport were compared. These studies indicated that ice hockey, handball, basketball, soccer, and rugby are popular team sports with a relatively high risk of injury. The aim of the study was to compare the characteristics and incidence of injuries in male youth amateur soccer and rugby players.

METHODS

This prospective cohort study comprised an initial baseline examination to ascertain the characteristics of the players and their level of performance, and a one season observation period during which a physician visited the team weekly and documented all occurring injuries. Twelve soccer and 10 rugby school teams with male amateur players aged 14-18 years were selected for the study. 145 soccer and 123 rugby players could be followed up over one season.

RESULTS

Comparison of the incidence of soccer and rugby injuries indicated that rugby union football was associated with a significantly higher rate of injury than soccer. The differences were pronounced for contact injuries, injuries of the head, neck, shoulder, and upper extremity, as well as for concussion, fractures, dislocations, and strains. Rugby players incurred 1.5 times more overuse and training injuries in relation to exposure time, and 2.7 times more match injuries than soccer players. Three rugby players but no soccer players had to stop their participation in sport because of severe injury.

CONCLUSION

The incidence of injury in New Zealand school teams playing soccer or rugby union is high, probably in part because of the low ratio of hours spent in training relative to hours spent playing matches. The development and implementation of preventive interventions to reduce the rate and severity of injury is recommended.

The Role of Central μ Opioid Receptors in Opioid-Induced Itch in Primates

Pruritus (itch sensation) is a significant clinical problem. The aim of this study was to elucidate the roles of opioid receptor types and the site of action in opioid-induced itch in monkeys. Observers who were blinded to the conditions counted scratching after administration of various drugs. Intravenous (i.v.) administration of mu opioid receptor (MOR) agonists (fentanyl, alfentanil, remifentanil, and morphine) evoked scratching in a dose- and time-dependent manner. However, the kappa opioid agonist U-50488H [trans-(+/-)-3,4-dichloro-N-methyl-N-(2-[1-pyrrolidinyl]-cyclohexyl)-benzeneacetamide] and delta opioid agonist SNC80 [(+)-4-[(alphaR)-alpha-[2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl]-3-methoxybenzyl]-N,N-diethylbenzamide] did not increase scratching. Intrathecal (i.t.) administration of peptidic MOR agonist [D-Ala2,N-Me-Phe4,Gly5-ol]-enkephalin (DAMGO, 0.00032-0.01 mg) evoked scratching, but i.v. DAMGO (0.01-1 mg/kg) did not increase scratching. A similar difference between i.t. and i.v. effectiveness was seen with morphine. Antagonist studies revealed that i.v. administration of an opioid receptor antagonist (naltrexone, 0.0032-0.1 mg/kg) dose dependently attenuated scratching induced by i.v. fentanyl (0.018 mg/kg) or morphine (1 mg/kg). However, a peripherally selective opioid antagonist (quaternary naltrexone, 0.0032-0.32 mg/kg) did not block i.v. fentanyl- or morphine-induced scratching. Moreover, a histamine antagonist (diphenhydramine, 0.1-10 mg/kg), failed to attenuate scratching induced by i.t. morphine (0.032 mg) or i.v. morphine (1 mg/kg). Pretreatment with a selective MOR antagonist (clocinnamox, 0.1 mg/kg), but not kappa or delta opioid antagonists (nor-binaltorphimine or naltrindole), blocked i.t. morphine-induced scratching. Together, these data suggest that MOR, not other opioid receptor types or histamine, mediates scratching evoked by opioid analgesics. More important, this study provides in vivo pharmacological evidence that activation of central MOR plays an important role in opioid-induced itch in primates.

Marked inactivation of O6-alkylguanine-DNA alkyltransferase activity with protracted temozolomide schedules

Temozolomide, an oral DNA methylator that inactivates the DNA repair enzyme O(6)-alkylguanine-DNA alkyltransferase (AGAT), has demonstrated anticancer activity on protracted schedules. Protracted schedules may lead to an 'autoenhancement' of temozolomide's inherent cytotoxic potential by cumulative reduction of the cell's capacity for AGAT-mediated DNA repair and resistance. This study was undertaken to characterise AGAT inactivation and regeneration in the peripheral blood mononuclear cells (PBMCs) of patients treated on two protracted temozolomide schedules. O(6)-alkyl guanine-DNA alkyltransferase activity was measured in the PBMCs of patients treated on two phase I protracted temozolomide studies. Patients were treated daily for either 7 days every 2 weeks (Schedule A) or 21 days every 4 weeks (Schedule B). The effects of various temozolomide doses (75-175 mg m(-2)), treatment duration (7-21 days), and temozolomide plasma levels on AGAT inactivation and regeneration, as well as the relation between AGAT inactivation and toxicity, were studied. O(6)-alkyl guanine-DNA alkyltransferase activity in PBMCs was measured serially in 52 patients. Marked inactivation of AGAT occurred following 7 days of temozolomide treatment, with mean AGAT activity decreasing by 72% (P<0.0001). Similarly, mean AGAT activity decreased by 63 and 73% after 14 and 21 days of treatment, respectively (P<0.001 for both comparisons). O(6)-alkyl guanine-DNA alkyltransferase inactivation was greater after 7 days of treatment with higher doses of temozolomide than lower doses and remained markedly reduced 7 days post-treatment. However, AGAT inactivation following temozolomide treatment for 14 and 21 days was similar at all doses. On the continuous 21-day schedule, AGAT inactivation was significantly greater in patients who experienced severe thrombocytopenia than those who did not (90.3+/-5.5 vs 72.5+/-16.1%, P<0.045). In conclusion, protracted administration of temozolomide, even at relatively low daily doses, leads to significant and prolonged depletion of AGAT activity, which may enhance the antitumour activity of the agent.

Inhibition of the aminopeptidase from Aeromonas proteolytica by L-leucinephosphonic acid. Spectroscopic and crystallographic characterization of the transition state of peptide hydrolysis

The nature of the interaction of the transition-state analogue inhibitor L-leucinephosphonic acid (LPA) with the leucine aminopeptidase from Aeromonas proteolytica (AAP) was investigated. LPA was shown to be a competitive inhibitor at pH 8.0 with a K(i) of 6.6 microM. Electronic absorption spectra, recorded at pH 7.5 of [CoCo(AAP)], [CoZn(AAP)], and [ZnCo(AAP)] upon addition of LPA suggest that LPA interacts with both metal ions in the dinuclear active site. EPR studies on the Co(II)-substituted forms of AAP revealed that the environments of the Co(II) ions in both [CoZn(AAP)] and [ZnCo(AAP)] become highly asymmetric and constrained upon the addition of LPA and clearly indicate that LPA interacts with both metal ions. The X-ray crystal structure of AAP complexed with LPA was determined at 2.1 A resolution. The X-ray crystallographic data indicate that LPA interacts with both metal centers in the dinuclear active site of AAP and a single oxygen atom bridge is absent. Thus, LPA binds to the dinuclear active site of AAP as an eta-1,2-mu-phosphonate with one ligand to the second metal ion provided by the N-terminal amine. A structural comparison of the binding of phosphonate-containing transition-state analogues to the mono- and bimetallic peptidases provides insight into the requirement for the second metal ion in bridged bimetallic peptidases. On the basis of the results obtained from the spectroscopic and X-ray crystallographic data presented herein along with previously reported mechanistic data for AAP, a new catalytic mechanism for the hydrolysis reaction catalyzed by AAP is proposed.

Lameness in feedlot cattle

This article examines the various causes of lameness in feedlot cattle, with an emphasis on clinical signs, treatment, and prevention. Specific conditions are discussed, including interdigital necrobacillosis, laminitis, feedlot injuries, and feedlot lameness associated with Mycoplasma bovis. Immune management of the foot is also reviewed.

Patterns of changes in human immunodeficiency virus type 1 V3 sequence populations late in infection

We have used a V3-specific heteroduplex tracking assay (V3-HTA) with probes from two different human immunodeficiency virus type 1 (HIV-1) subtypes to examine the extent and pace of HIV-1 evolution late in infection. Twenty-four subjects with advanced HIV-1 infection (CD4(+) T-cell count, <100/microl) and stable viral loads were studied using blood plasma samples collected over a study period of approximately 9 months, during which time most of the subjects were treated with reverse transcriptase inhibitors. The V3-HTA patterns from the first and last time points were evaluated initially to determine the amounts of change in V3 sequence populations, which were primarily changes in abundance in preexisting sequence populations. Three of the 24 subjects had major changes (greater than 50% total change in the relative abundance of the sequence populations), 11 subjects had intermediate changes (10 to 50% total change), and 10 subjects had minimal changes (less than 10% total change). The average total amount of change was between two- and threefold greater in subjects with X4-like variants, although there was no correlation between average viral load and the presence of X4-like variants. V3-HTA patterns in monthly samples from 11 of the subjects were also compared. In two subjects, the amount of change exceeded 40% in a 1-month period. Overall, the pace of change in V3 populations varied between subjects and was not constant within a subject over time. Sequence analysis of the V3 variants showed that R5-like variants (not containing any X4-associated substitutions) continued to be maintained in three subjects in the presence of X4-like variants, indicating that X4 variants do not always outgrow R5 variants. The coreceptor usage of the V3 sequences from two subjects was determined using a cell fusion assay. One subject had an X4 variant that was maintained at a low level for at least 9 months, during which time the predominant variants were R5X4 (dualtropic), while in the second subject the reverse situation was observed. One of the dualtropic variants had a novel sequence motif in V3, suggesting another evolutionary pathway to altered tropism. These studies begin to probe the complexities and pace of V3 evolution in vivo, revealing dynamic patterns of change among multiple V3 sequence variants in a subset of subjects.

Continuous-wave, singly-resonant, optical parametric oscillator based on periodically poled KTiOPO4

A continuous-wave singly-resonant optical parametric oscillator (SRO) has been implemented using a 20 mm long crystal of periodically poled KTiOPO 4 (PPKTP) intracavity-pumped at room temperature within a Ti:sapphire laser. The device delivers a maximum output power of 455 mW at a non-resonant idler wavelength of 2.47 microm. The 28.5-microm grating PPKTP crystal provides SRO tuning over 1.14-1.27 microm (signal) and 2.23-2.73 microm (idler) limited by optical coating bandwidths and corresponding to a pump tuning range of 805.5-811.2 nm. Temperature tuning of the device generated signal and idler ranges of 1.18-1.26 microm and 2.29-2.57 microm, respectively, corresponding to an average tuning rate of 1.2 nm/degree (signal) and 4.5 nm/degree (idler). Ring-cavity configuration of the device resulted in generation of 115 mW of single-frequency idler output at 2.35 microm.

Two-dimensional crystallization of streptavidin: in pursuit of the molecular origins of structure, morphology, and thermodynamics

The streptavidin two-dimensional (2D) crystallization model has served as a paradigm for molecular self-assembly at interfaces. We have developed quantitative Brewster angle microscopy for the in situ measurement of spatially resolved relative protein surface densities. This allows investigation of both the thermodynamics and morphologies of 2D crystal growth. For crystal structure analysis, we employ TEM on grown crystals transferred to solid substrates. Comparison of results between commercially available streptavidin, recombinant streptavidin, and site-directed streptavidin mutants has provided insight into the protein protein and protein-lipid interactions that underlie 2D crystallization.

Severe respiratory depression in a patient with gastroparesis while receiving opioids for pain

OBJECTIVE

To increase awareness of the possibility of severe respiratory depression when oral opioids are used in patients with gastrointestinal motility disorders.

SETTING

A major county hospital affiliated with a university.

PATIENT

A patient with severe pain from diabetic muscle necrosis with a history of gastroparesis.

INTERVENTIONS

Attempted pain control with oral and transdermal opioids.

RESULTS AND CONCLUSIONS

Pain control in our patient was attempted using potent oral opioids on two occasions. However, this patient suffered severe respiratory depression after each attempt. Transdermal delivery of fentanyl eventually provided satisfactory pain relief without side effects. We conclude that patients with gastrointestinal motility disorders may be at high risk for side effects of oral opioids due to altered absorption kinetics. Suggestions are made for alternative strategies for opiate delivery in patients with gastrointestinal motility disorders.

Inhibition of the aminopeptidase from Aeromonas proteolytica by aliphatic alcohols. Characterization of the hydrophobic substrate recognition site

Seven aliphatic and two aromatic alcohols were tested as reporters of the substrate selectivity of the aminopeptidase from Aeromonas proteolytica (AAP). This series of alcohols was chosen to systematically probe the effect of carbon chain length, steric bulk, and inhibitor shape on the inhibition of AAP. Initially, however, the question of whether AAP is denatured in the presence of aliphatic alcohols was addressed. On the basis of circular dichroism (CD), electronic absorption, and fluorescence spectra, the secondary structure of AAP, with and without added aliphatic alcohols, was unchanged. These data clearly indicate that AAP is not denatured in aliphatic alcohols, even up to concentrations of 20% (v/v). All of the alcohols studied were competitive inhibitors of AAP with K(i) values between 860 and 0.98 mM. The clear trend in the data was that as the carbon chain length increases from one to four, the K(i) values increase. Branching of the carbon chains also increases the K(i) values, but large bulky groups, such as that found in tert-butyl alcohol, do not inhibit AAP as well as leucine analogues, such as 3-methyl-1-butanol. The competitive nature of the inhibition indicates that the substrate and each alcohol studied are mutually exclusive due to binding at the same site on the enzyme. On the basis of EPR and electronic absorption data for Co(II)-substituted AAP, none of the alcohols studied binds to the dinuclear metallo-active site of AAP. Thus, reaction of the inhibitory alcohols with the catalytic metal ions cannot constitute the mechanism of inhibition. Combination of these data suggests that each of these inhibitors bind only to the hydrophobic pocket of AAP and, consequently, block the binding of substrate. Thus, the first step in peptide hydrolysis is the recognition of the N-terminal amino acid side chain by the hydrophobic pocket adjacent to the dinuclear active site of AAP.

Trauma 24-hour observation critical path

BACKGROUND

The 24-hour observation critical pathway for trauma is a clinical tool developed to expedite health care delivery to minimally injured patients. The use of patient care, BS, guidelines and physician-approved standing orders was implemented in a Level I trauma center.

METHODS

A retrospective chart review was performed of 122 patients admitted via the emergency department between December 1, 1993, and May 31, 1994. All patients were evaluated in the emergency department by emergency medicine and trauma physicians and deemed appropriate for 24-hour observation. The information collected included patient demographics, hospital charges, injuries, length of stay, diagnostic tests, consultations, and variances from the critical pathway.

RESULTS

During the 6-month study period, there were 600 trauma admissions. Of those admissions, 122 patients (20%) were evaluated in the emergency department and deemed appropriate for enrollment in the 24-hour observation pathway. The charts of these patients were reviewed. Fourteen admissions were determined inappropriate for the critical pathway because of the severity of injuries or discharge against medical advice. One hundred eight charts were evaluated further. Eighty-nine patients (80%) completed the critical pathway with a length of stay of 24 hours.

CONCLUSION

The 24-hour observation critical pathway was designed and used appropriately as exemplified by an overall 80% completion rate. The critical pathway offers a mechanism to streamline care of the minimally injured trauma patient. It also serves as a quality-improvement tool for increasing efficiency, decreasing utilization of resources, and decreasing length of stay.

Mechanistic studies on the aminopeptidase from Aeromonas proteolytica: a two-metal ion mechanism for peptide hydrolysis

The aminopeptidase from Aeromonas proteolytica (AAP) is uncompetitively inhibited by fluoride ion at pH 8.0 with an inhibition constant (Ki) of 30 mM. Thus, fluoride inactivates AAP only after substrate binding, and only a single fluoride ion binds to AAP. On the other hand, chloride ion does not inhibit AAP up to concentrations of 2 M at pH 8.0. The pH dependence of fluoride inhibition of AAP was measured over the pH range 6.0-9.5. Between pH values of 6.0 and 9.0, fluoride ion acts as a pure uncompetitive inhibitor of AAP, and the Ki increases from 1.2 to 370 mM. From a plot of pKi vs pH, a pKa value of 7.0 +/- 0.3 was extracted which corresponds to a single deprotonation process. At pH values higher than 9.0, the fluoride inhibition pattern changes to competitive. This change in inhibition pattern was attributed to a change in ionic strength or perhaps pH of the solution since fluoride ion was also found to become a competitive inhibitor of AAP at pH 8.0 in the presence of 2 M NaCl. These data, taken together with previous kinetic studies of mono- and dinuclear hydrolases with fluoride ion, suggest that a Zn(II)-bound water/hydroxide exists at the dimetal active site of AAP with a pKa of 7.0 and that this water/hydroxide acts as the active site nucleophile. The hydrolysis of L-leucine-p-nitroanilide was measured spectrophotometrically in triplicate between 25 and 85 degrees C at eight substrate concentrations ranging from 5 to 800 microM. From these data, Km values were derived at each temperature studied and were found to increase exponentially with increasing temperature. Moreover, the calculated Vmax values were also found to increase over this temperature range, mimicking the Km values. An Arrhenius plot was constructed from k(cat) values and was found to be linear over the temperature range 25-85 degrees C, indicating that the rate-limiting step in AAP peptide hydrolysis is product formation and does not change as a function of temperature. From the slope of the line, the activation energy (Ea) was calculated to be 36.5 kJ/mol. The enthalpy and entropy of activation at 25 degrees C calculated over the temperature range 298-358 K were found to be 34.0 kJ/mol and -94.2 J/(mol x K), respectively. The free energy of activation at 25 degrees C was found to be 62.1 kJ/mol. Combination of the available X-ray crystallographic data with the present kinetic and thermodynamic results, as well as the previously reported kinetic and spectroscopic data, has allowed a detailed catalytic mechanism for AAP to be proposed.

Expression of members of a novel membrane linked metalloproteinase family (ADAM) in human articular chondrocytes

Using resting chondrocytes derived from human articular femoral head and a conditionally immortalised human articular chondrocyte cell line we have studied the expression of members of the novel metalloproteinase/disintegrin family termed ADAM. Using RT-PCR we can detect the expression of ADAM-12 a novel family member isolated from myeloma cells [1]. We also find expression of ADAM 10 a functional metalloproteinase/disintegrin first isolated from bovine brain and ADAM-15 a metallodisintegrin isolated from mammary derived epithelial cells. Northern blotting was used to confirm expression. One main transcript is visible for ADAM-12 whereas both ADAM-10 and ADAM-15 have multiple transcripts indicating possible RNA variants potentially derived from alternative splicing or alternative use of polyadenylation sites. Since chondrocytes are proposed as an important source of metalloproteinase enzymes involved in joint pathology the potential relevance of the expression of these molecules to connective tissue disorders is discussed.

Cloning of a novel membrane-linked metalloproteinase from human myeloma cells

We have isolated a novel cDNA from human myeloma cells encoding a member of the reprolysin family of metalloproteinases. Derived amino acid sequence predicts a protein of approx. 76 kDa. The open reading frame predicts the presence of a leader peptide, a pro-peptide with a 'cysteine switch', a metalloproteinase domain, a disintegrin-like domain, a cysteine-rich domain, an epidermal growth factor-like domain and a putative transmembrane sequence. Expression of the mRNA for this metalloproteinase has been demonstrated in human myeloma cells.

A method of detecting the muscle pain threshold using an objective software-mediated technique

This paper describes the reliability of a new procedure of applying force to a muscle site using a computer-mediated myometric procedure to measure a discomfort-pain threshold. 24 female subjects were divided into four groups. Each group was tested on three occasions (trial) at four muscle sites (site) repeated daily over four days (day). Each group received one of four different rates of force application (ramp). Analysis of variance (ramp by day by site by trial) showed a significant main effect for trials and discomfort-pain threshold at different muscle sites, but no significant main effect for days or ramps. Intraclass correlations for each muscle site were in the range of R = 0.73 to 0.98. This procedure appears to be a valid, reliable and nonintrusive means of assessing the muscle discomfort-pain threshold.

Membrane-interactive phospholipids inhibit HIV type 1-induced cell fusion and surface gp160/gp120 binding to monoclonal antibody

Membrane-interactive phospholipids (PLs), previously evaluated for activity against HIV-1 in vitro, are known to affect late steps in viral replication. Studies were done to determine the effects of PL analogs on post-translational processing of HIV-1 proteins, binding of viral surface gp160/gp120 to CD4 receptor, and HIV-1-induced cell fusion. Results of this investigation indicated that PL alone (1-octadecanamido-2-ethoxypropyl-rac-3-phosphocholine, CP-51) and PL-AZT conjugate (1-octadecanamido-2-ethoxypropyl-rac-3-phospho-3'- azido-3'-deoxythymidine, CP-92) have no effect on HIV-1-induced syntheses or processing of gp160/gp120, pr51, p24, or p17 (including myristoylation) in infected cells. Progeny HIV-1 particles made in CP-92-treated H9IIIB cells contained gp120, pr51, and p24; however, these virus particles had reduced capacity to bind to CD4+ cells. Both CP-51 and CP-92 inhibited syncytium (cell fusion) formation between treated HIV-1-infected cells and uninfected CD4+ cells, and, they reduced HIV-1 gp160/gp120 binding to CD4+ cells and monoclonal antibody. These results suggest that anti-HIV-1 activity of PL compounds involves alteration of cell surface membranes and viral envelopes. Phospholipid compounds are a novel class of membrane interactive compounds with potential use in blocking the spread of HIV-1 infection and pathogenesis in AIDS.

Evaluation of sensitivity and specificity of six D-dimer latex assays

The results of six commercially available D-Dimer latex assays were compared with those obtained by two D-Dimer enzyme-linked immunosorbent assay; this comparison was done by assessing the sensitivity and specificity of the assays. Results indicated that five of the six latex assays were unable to detect consistently D-Dimer levels (ie, equal to the claims stated in the manufacturers' package inserts). Performance, in order of decreasing sensitivity ([true positive/(true positive+false negative)] as compared with the enzyme-linked immunosorbent assay results), was as follows: ACCUCLOT D-Dimer (Sigma Diagnostics, St Louis, Mo) (93.8%) greater than Fibrinosticon (Organon Teknika Corp, Durham, NC) (81.3%) greater than D-Di Test (Diagnostica Stago, Asnières, France) (68.8%) greater than Dade Dimer-test Latex Assay (Baxter Diagnostics Inc, Miami, Fla) (59.4%) greater than Dimertest Latex Kit (American Diagnostica Inc, Greenwich, Conn) and DimerKlone (Ortho Diagnostic Systems Inc, Raritan, NJ) (56.3%). The estimated sensitivity for the lowest sensitivity assays (group 1) (American Diagnostica Inc, Ortho Diagnostic Systems, and Dade Diagnostics) was approximately 1.5 mg/L; the estimated sensitivity for the moderate sensitivity assays (group 2) (Organon Teknika Corp and Diagnostica Stago) was approximately 1.0 mg/L; and the estimated sensitivity for the highest sensitivity assay (group 3) (Sigma Chemical Co) approached a detection limit in the 0.25- to 0.50-mg/L range.

Effect on verapamil on ventricular function: studies in denervated human heart

Verapamil has complex influences on ventricular function owing to its direct myocardial effects, vasodilation, and reflex activation of the sympathetic nervous system. To investigate the direct myocardial effects of verapamil in humans independent of reflex sympathetic stimulation, we administered the drug to 13 recent heart transplant recipients with denervated ventricles. Hemodynamics and radionuclide angiograms were recorded at baseline, with altered loading conditions, and after intravenous (i.v.) verapamil (median dose 4 mg). Left ventricular (LV) systolic and diastolic function was analyzed by systolic pressure-volume relations (SPVR) and peak filling rate (PFR), respectively. Verapamil caused a decrease in blood pressure (BP) and heart rate (HR) with increases in right atrial pressure (RAP 6 +/- 3-8 +/- 3, p < 0.01) and pulmonary artery wedge pressure (PAWP, 9 +/- 3-11 +/- 3 mm Hg, p < 0.01) pressures. LV ejection fraction (EF) decreased (69 +/- 7-66 +/- 8%, p < 0.02) in association with an increase in LV end-systolic counts (3.45 +/- 1.27 to 4.72 +/- 1.78 kcts, p < 0.001). In 11 of 13 patients, the SPV point after verapamil administration was decreased from the line established during altered loading conditions. PFR (4.05 +/- 0.81 to 4.11 +/- 0.76 EDV/s) was unchanged. In the denervated ventricle, verapamil has negative chronotropic and inotropic effects with minimal effects on PFR.

A technique for postoperative irradiation of carcinomas of the larynx and hypopharynx

Postoperative radiation is commonly employed for advanced lesions of the larynx and hypopharynx which have undergone a laryngectomy. It is technically difficult to achieve a homogeneous distribution of irradiation throughout the treatment volume because of the marked variation in contour across the treated area. We have described a technique which employs a 15 degrees lateral kick-out of the treatment table and a 15 degrees gantry angle above the horizontal for each of two lateral fields. This technique has certain advantages over other techniques previously described in the literature. By adding a gantry angle of 15 degrees above the horizontal to the kick-out lateral position of the table, we have found that we were able to decrease the amount of irradiation to the shoulder, to improve the dose to the posterior superior mediastinum, to lower the applied dose, and to avoid a hot spot overlying the spinal cord in the superior posterior portion of the field. This technique is particularly useful in patients who lack the flexibility to move their shoulders posteriorly and inferiorly.

Effects of acute alterations in left ventricular loading conditions on peak filling rate in the denervated (transplanted) ventricle

Peak filling rate is an indicator of left ventricular (LV) diastolic function. It is influenced by heart rate, loading conditions, sympathetic nervous system activity, ejection fraction and other factors. To determine the effect of altered loading conditions on peak filling rate, independent of heart rate and sympathetic nervous system activity, 12 patients were studied 3 weeks after orthotopic heart transplantation. Plasma catecholamine level, heart rate and ejection fraction were not changed by any maneuver. Nitroglycerin caused a decrease in pulmonary artery wedge pressure (9 +/- 2 to 6 +/- 1 mm Hg, p less than 0.001) and in absolute peak filling rate (46.0 +/- 3.0 to 42.8 +/- 2.5 kcts/s, p less than 0.01), but no change in normalized peak filling rate. Volume infusion increased pulmonary artery wedge pressure (9 +/- 2 to 12 +/- 2 mm Hg, p less than 0.001) and absolute peak filling rate (46.0 +/- 3.0 to 51.5 +/- 5.3 kcts/s, p less than 0.01), but peak filling rate normalized to stroke volume was unchanged. During nitroglycerin and volume infusions, there was a high correlation between changes in pulmonary artery wedge pressure and absolute peak filling rate (r = 0.82, p less than 0.001). With normalization of peak filling rate, these variables correlated less well. With methoxamine, 4 patients demonstrating systolic dysfunction had a decrease in absolute and normalized peak filling rate despite a large increase in pulmonary artery wedge pressure. The other 8 patients without systolic dysfunction had an increase in pulmonary artery wedge pressure with increased absolute but unchanged normalized peak filling rate.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of H-2 region and genetic background on hormone-induced ovulation rate, puberty, and follicular number in mice

We have examined the effects of major histocompatibility (H-2) haplotypes and genetic background (all loci other than the H-2 region) on hormone-induced ovulation rate in congenic strains of mice. In comparison with the H-2a haplotype, the H-2b haplotype increased hormone-induced ovulation rate 92% on the A/J (A) genetic background. However, H-2 haplotype did not affect hormone-induced ovulation rate on the C57BL/10J (C57) genetic background. The H-2b-linked gene(s) increased hormone-induced ovulation rate on the A/J genetic background largely by (1) enhancing the maturation of follicles in response to pregnant mare's serum gonadotrophin (PMSG) and (2) altering the stages of follicular development which can be induced to ovulate in response to human chorionic gonadotrophin (hCG). The observed effects of H-2 on hormone-induced ovulation rate were not explained by differences in the timing of puberty, the number of follicles present in untreated females, or the incidence of follicular atresia. The effect of genetic background on hormone-induced ovulation rate was much greater than was the effect of the H-2 region. We found that hormone-induced ovulation rate was five- to six-fold higher on the C57 genetic background than on the A genetic background. The C57 genetic background increased hormone-induced ovulation rate by (1) enhancing the induction of follicular maturation in response to gonadotropins and (2) by reducing the incidence of follicular atresia.

Laser-induced fluorescence in high pressure solid propellant flames

The application of laser-induced fluorescence (LIF) to the study of high pressure solid propellant flames is described. The distribution of the OH and CN radicals was determined in several solid propellant flames at pressures up to 3.5 MPa. The greatest difficulty in these measurements was the separation of the desired LIF signals from the large scattering at the laser wavelength from the very optically thick propellant flames. Raman experiments using 308-nm excitation were also attempted in the propellant flames but were unsuccessful due to LIF interferences from OH and NH.

A preliminary evaluation of the Gonozyme test

Gonozyme is a solid-phase enzyme immunoassay that detects antigens of Neisseria gonorrhoeae in clinical specimens. The test was 100% sensitive and 96.8% specific when applied to 71 urethral specimens from men with symptomatic urethritis, and 89.5% specific for 19 urethral specimens from men examined after eradication of gonorrhea by antibiotics. For cervical specimens obtained before therapy from 368 women with gonorrhea, the Gonozyme test had a sensitivity of 88.5% and a specificity of 94.3%. The test was 100% specific when used for testing of 37 cervical specimens obtained after therapy of gonorrhea. The predictive values of a positive Gonozyme test were 90.5% for cervical specimens from women attending a sexually transmitted disease clinic and 97% for urethral specimens from men with urethritis. The predictive values of negative Gonozyme tests in these same circumstances were 100% for urethral specimens and 93.6% for cervical specimens.

Characterization of Bacteroides asaccharolyticus and B. melaninogenicus oral isolates

Experiments were designed to characterize a number of oral "pigmented" Bacteroides isolates with regard to their pathogenicity in an experimental model system and a number of other properties. T these include fatty acid determination, hemagglutination studies, collagenase and protease activities, and vitamin K dependency. Oral B, asaccharolyticus and B, melaninogenicus isolates differed from one another in phenylacetic acid production, hemagglutination, collagenase activity, and pathogenicity. All B. asaccharolyticus were found to be pathogenic in the vivo mixed infection model and this property could be correlated with biochemical enzymatic activities.

Spectinomycin-resistant Neisseria gonorrhoeae

Neisseria gonorrhoeae resistant to high levels of spectinomycin (more than 2,048 microng/ml), were isolated from specimens obtained from a patient with urethritis. The bacterial resistance to spectinomycin is probably due to ribosomal changes that are a result of a chromosomal mutation. If spectinomycin fails to cure gonorrhea, spectinomycin resistance should be considered.

New method for the isolation and identification of methanogenic bacteria

A new technique is reported for the rapid growth and detection of methanogenic bacteria by using petri plates. The method employs an anaerobic glove box containing an inner chamber with separate gas-flushing facilities. The numbers of methanogenic bacteria recovered from domestic sewage sludge are comparable to those recovered by other methods. The methanogenic organisms isolated from sludge include Methanosarcina, Methanospirillum, Methanobacterium strain M.o.H., and Methanobacterium formicicum. Identification of colonies containing methanogenic bacteria is facilitated by taking advantage of the unique fluorescence properties of these organisms. Colonies as small as 0.5 mm can be detected by exposing them to long-wave ultraviolet light.