Fourier transform infrared spectrometry: a versatile technique for real world samples

The versatility of FTIR spectrometry was explored by considering a variety of samples drawn from industrial applications, materials science and biomedical research. These samples included polymeric insulators, bauxite ore, clay, human hair and human skin. A range of sampling techniques suitable for these samples is discussed, in particular FTIR microscopy, FTIR emission spectroscopy, attenuated total reflectance and photoacoustic FTIR spectrometry. The power of modern data processing techniques, particularly multivariate analysis, to extract useful information from spectral data is also illustrated.

How to hire great employees

The average dentist (as well as the average business person) tends to treat the hiring decision as a random event. However, it is relatively easy to update your hiring skills so that you can consistently select excellent employees. Hiring good employees is critical, because hiring poor ones can bring a practice to its knees. Many employers have a difficult time interviewing applicants, and many good employees have a difficult time being interviewed. The first step in successful hiring is to look carefully at the resumes you have on hand. After you've narrowed the field down to six or 10 potential candidates, you should consider the specific competencies required to do the job and develop relevant interview questions to ask the candidates. When you finally conduct interviews, your overall objective is to give the candidate an opportunity to tell you about their skills and experience, and how they apply to your operation. The interview is your time to get to know everything you can about the candidate, so use it wisely. Finally, you must make your decision.

High-volume nonionic dimeric contrast medium: first experiences during complex coronary interventions

Interventional cardiology is a rapidly developing field of medicine with annually increasing numbers of coronary interventions. Especially through the development of alternative techniques for coronary angioplasty, new indications have been found and more difficult lesions are tackled. Inevitably, such complex interventions are time-consuming and require high amounts of contrast medium. Newer, mostly nonionic agents have been developed with improved tolerability as well as fewer cardiac and renal side effects due to their nonionic, hydrophilic structure, and their osmolality isotonic to plasma. This study sought to investigate the effects of high-volume nonionic, dimeric contrast medium during coronary interventions with special emphasis on renal and hemodynamic side effects during routine hospital stays. Retrospectively, 25 consecutive patients (age 56 +/- 10 yr) with normal renal and cardiac function receiving > 500 ml of the nonionic dimeric contrast medium iodixanol during complex coronary interventions were analyzed. The analysis was based on serum creatinine levels 1 day before and 2 days after contrast medium administration for the monitoring of renal function. Additionally, heart rate and left ventricular pressures were evaluated before and after left ventricular angiography. Mean serum creatinine rose from 0.9 +/- 0.2 mg/dl to 1.1 +/- 0.2 mg/dl (P < 0.05) after 2 days of coronary intervention. Heart rate, left ventricular systolic pressure, and left ventricular end-diastolic pressure did not change significantly. No major side effects were encountered in the short follow-up period of 2 days. Based on this retrospective analysis, high-volume nonionic, dimeric contrast medium administration in patients without preexisting renal insufficiency is associated with little impairment of renal function, and has only minor hemodynamic and general side effects. Iodixanol 320 mg I/ml is well-tolerated and effective for the use of cardioangiography. Given the limitations of this retrospective analysis, future prospective studies should systematically address the effects of high-volume contrast medium administration in otherwise healthy patients as well as in high-risk patients undergoing coronary interventions.

Neck pain as a presenting symptom in malignant hypertension

Neck pain, unrelated to trauma, is relatively common and is usually presumed to be musculoskeletal in origin. A patient presented with an unusual and serious cause of neck pain-malignant hypertension. The mechanism of the neck pain may be incipient tonsillar herniation of the cerebellum caused by raised intracranial pressure.

Congestive cardiac failure and aortic dissection in a young man with Marfan's syndrome

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Age, smoking and the activity of the mono-oxygenase aryl hydrocarbon hydroxylase in isolated human peripheral blood monocytes

Age-associated changes in the microsomal mono-oxygenase enzyme, aryl hydrocarbon hydroxylase (AHH), were investigated in peripheral blood monocytes isolated from young and elderly subjects. Young subjects were selected from the age group < 35 years; elderly subjects were > 70 years. AHH activity, expressed as nM 3-hydroxy benzopyrene formed/10(6) cells/h of incubation, was similar in young and elderly non-smokers (elderly = 6.7 +/- 1.8; young = 9.1 +/- 0.9; p > 0.05). In smokers, contrary to some previous reports, AHH activity was not significantly higher than in non-smokers of similar age (elderly smokers = 8.6 +/- 1.0; young smokers = 10.5 +/- 2.4; p > 0.05). There was no significant difference between young and elderly smokers (p > 0.05). We conclude that: (a) AHH activity is similar in young and old non-smoking individuals; (b) no significant differences were detected in in vivo induction of this enzyme activity between smokers and non-smokers.

Plasma aspirin esterase activity in elderly patients undergoing elective hip replacement and with fractured neck of femur

Plasma aspirin esterase activity was measured in eight elderly patients undergoing elective hip replacement, and in 11 presenting with femoral-neck fracture. Elective hip surgery was associated with a marked and significant decline in esterase, from 330 +/- 35.9 (SE) (nmol salicylate/ml plasma/min) pre-operatively to 236 +/- 35.6 on the third post-operative day, and returning to normal (359 +/- 24.3) at recovery phase. Patients with fractured neck of femur showed a depressed esterase activity on admission (221 +/- 12.7), rising towards normal (290 +/- 15.4) on recovery. All of these changes were accompanied by a marked acute-phase response, both to injury and surgery. The data suggest that elderly patients experiencing injury or undergoing surgery may have significantly impaired drug metabolism, at least as far as this enzyme is concerned.

[Attention deficit disorder and anxiety disorders: a co-occurrence study]

Recent epidemiological studies have evaluated the concomitant occurrence of several disorders in children. Over the last few years there have been reports from Anglo-Saxon investigators that many children with attention deficit disorder-hyperactivity also have anxiety disorders. This is the first French study addressing this issue. The prevalence and types of anxiety disorders were determined in 50 children with attention deficit disorder-hyperactivity using a questionnaire and a semi-structured interview. Over 40% of subjects had at least one concomitant anxiety disorder meeting DSM-III-R criteria. Hyperanxiety and separation anxiety were the most common anxiety disorders. Among patients with anxiety, over 40% had more than one anxiety disorder. These data are consistent with earlier Anglo-Saxon reports. Symptoms of anxiety which discriminated hyperactive children with and without anxiety disorders were identified.

Dose dependent induction of the microsomal monooxygenase aryl hydrocarbon hydroxylase in isolated peripheral blood monocytes: the influence of age

The induction of the microsomal monooxygenase benzo(alpha)pyrene hydroxylase was investigated in isolated peripheral blood monocytes from young and old donors, after exposure to different concentrations of benzanthracene as an inducing agent. The sensitivity of the cells to the inducing stimulus was not dependent on the age of the donor. The mechanisms underlying impaired monooxygenase induction in the elderly remain to be clarified.

Age and the rate of induction of aryl hydrocarbon hydroxylase in isolated peripheral blood monocytes

We have measured the rate of induction of the microsomal monooxygenase enzyme aryl hydrocarbon hydroxylase (AHH) in isolated peripheral blood monocytes from young and elderly donors. There was no effect of age on rate of induction. The mechanisms underlying impaired induction of drug metabolism in elderly people remain to be clarified.

The association of age with the induction of drug-metabolizing enzymes in human monocytes

In vivo studies in man suggest that the enzyme-inducing effect of environmental influences such as drugs or smoking may be reduced in elderly people. We have investigated the basal activity and response to induction of the oxidative enzyme, aryl hydrocarbon hydroxylase (AHH) in human monocytes. Three groups were studied: ten fit young, ten fit elderly and eight frail elderly subjects. Significant induction of AHH activity in response to the hydrocarbon benz(a)anthracene was achieved in all three groups. No impairment of basal AHH activity or in the synthesis of new enzyme protein was noted with age or frailty. There is still no direct evidence of an age-associated fall in drug metabolizing enzyme activities in man.

Nuclear imaging and the assessment of human Fc receptor function: studies in systemic lupus erythematosus

In vivo immune clearance of immunoglobulin G sensitized autologous erythrocytes (rbc) was studied in nine patients who fulfilled American Rheumatism Association (ARA) criteria for systemic lupus erythematosus (SLE). Opsonized rbc were radiolabelled with technetium 99. The rate of radioactive blood clearance was measured, as was organ-specific radioactive uptake utilizing area-of-interest (AOI) measurements in a computerized scintigraphic imaging system. It was shown that dynamic quantitation of an AOI corresponding to the heart generated time-activity curves which approximated blood-clearance curves. Calculation of first order clearance (min per 50% decrease in counts) showed a highly significant correlation between rates derived from heart AOI curves and those derived from blood-clearance curves (r = 0.9483, P = 0.0003). Clearance curves showed a monoexponential slope in most patients. Further exploration of organ-specific AOI curves showed that percent splenic uptake and the nature of the splenic uptake curves varied between patients. These studies point toward a variable splenic role in Fc receptor function for SLE patients and further demonstrate the utility of nuclear imaging in studying immune clearance.

[Experimental endocrinological studies in gilts near the time of ovulation using Gn-RH vet. "Berlin Chemistry"]

Knowledge of endocrine processes in pro-oestrus and oestrus in conjunction with physiological alterations is of greatest importance to biotechnological control of follicular maturation and ovulation. Methods of hormonal analysis and ovarian diagnosis were used to check on the effectiveness of Gn-RH vet. "Berlin-Chemie" for induction of the luteinising hormone (LH) peak and ovulation. Release in gilts of LH was found to depend on dosage, after 100, 300, and 900 micrograms Gn-RH had been administered at 3 p.m. on the 4th day after synchronisation of ovulation. LH release and induction of ovulation due to these variants were insufficient in some of the animals. Ovulation was then decisively improved in animals with LH peak by subsequent injection of 300 or 900 micrograms Gn-RH at 8 a.m. on the 5th day. Repetitive injections of 300 micrograms Gn-RH at 8 and 8.45 a.m. on the 5th day did not trigger off increased LH release from the pituitary gland. The Gn-RH effect was substantially improved by use of an absorption-retarding preparation (polystyrene sulphonic acid).

Marketing a practical health care policy for the United States

A policy for universal health care in the United States has been proposed by leading health planners. All citizens of the United States should be entitled to basic health care of adequate quality. Basic care should include physicians, hospitals, and clinic services, emergency and preventive care, and certain other treatments and services. Key to this practical health care policy is the method by which it will be financed. This policy combines several widely discussed financial methods such as Medical Individual Retirement Accounts, catastrophic health insurance, and the combination of what is now known as Medicare and Medicaid into one umbrella package. Active competition within the health care delivery system is essential. To prepare the health care consumer for this competitive environment, an active marketing program by providers, corporations, and all levels of government is basic. For such a policy to be implemented, it must be marketed to the legislature, professional organizations within the health and insurance fields, to educators and to the public.

Pulmonary macrophages are attracted to inhaled particles through complement activation

Pulmonary macrophages play a central role in clearing inhaled particles from the lung. Previously, we showed that inhaled asbestos fibers activate complement-dependent chemotactic factors on alveolar surfaces to facilitate macrophage recruitment to sites of fiber deposition. In the studies presented here, we have tested a variety of inorganic particles for complement activation in vitro and correlated these data with results on particle-induced macrophage accumulation in vivo. We found that significant chemotactic activity was activated in rat serum and concentrated lavaged proteins by chrysotile and crocidolite asbestos, iron-coated chrysotile asbestos, fiberglass, and wollastonite fibers, as well as by carbonyl iron and zymosan particles. Ash from the Mt. St. Helens volcano did not induce chemotactic activity in either the serum or lavaged proteins. Rats were exposed to brief aerosols of each of the particles listed above (except zymosan). All the particle types studied were deposited primarily at first alveolar duct bifurcations. In addition, all of the particles, except Mt. St. Helens ash, induced at 48 h postexposure significant accumulations of macrophages at these sites. Time-course studies of carbonyl iron particle exposure demonstrated that iron induced a rapid macrophage response, but both particles and phagocytic macrophages were cleared from alveolar surfaces within 8 days after exposure. The Mt. St. Helens ash induced no macrophage accumulation at any time postexposure. We conclude that particles with a wide variety of physical characteristics are capable of activating complement and consequently attracting macrophages, both in vitro and in vivo. We suggest that complement activation is a mechanism through which pulmonary macrophages can detect inhaled particles on alveolar surfaces.

Parasuicide: interaction between inadequate parenting and recent interpersonal stress

We report a controlled study in which we searched for links between early family adversity and recent interpersonal stress in parasuicidal patients. Our subjects reported fewer adverse experiences in childhood than did the younger, predominantly female, patients investigated in previous studies. Nevertheless, 47% of our parasuicidal group, as compared to 19% of control subjects, reported a sequential pattern of relationship difficulties starting in childhood. The pattern of early exposure to neglectful and overprotective parenting followed by recent conflict or separations in adulthood was found to discriminate most clearly between the parasuicidal and control groups. We suggest that factors such as low self-esteem, a sense of helplessness in the face of adversity and an abiding insecurity in intimate relationships may variously account for this heightened vulnerability. We conclude that a history of adverse relationships beginning in childhood should alert primary care-givers to the risk of suicidal behaviour in patients who are exposed to distressing separations or interpersonal conflict.

Sialic acid mediates the initial binding of positively charged inorganic particles to alveolar macrophage membranes

Pulmonary macrophages phagocytize inhaled particles and are postulated to play a role in the development of pulmonary interstitial fibrogenesis. The basic biologic mechanisms through which inhaled particles bind to macrophage membranes and subsequently are phagocytized remain unclear. We hypothesize that positively charged particles bind to negatively charged sialic acid (SA) residues on macrophage membranes. Alveolar Macrophages (AM) were collected by saline lavage from normal rat lungs. The cells adhered to plastic coverslips in serum-free phosphate buffered saline at 37 degrees C for 45 min and then were maintained at 4 degrees C for the binding experiments. Even distribution of SA groups on AM surfaces was demonstrated by scanning electron microscopy of wheat germ agglutinin (WGA) conjugated to 50 nm gold spheres. The WGA is a lectin that binds specifically to sialic acid, and pretreatment of AM with this lectin prevented the binding of positively charged carbonyl iron (C-Fe) spheres, aluminum (Al) spheres, and chrysotile asbestos fibers to AM surfaces. Limulus protein, another lectin with binding specificity for SA, similarly blocked the binding of positively charged spheres and chrysotile asbestos fibers but not negatively charged glass spheres or crocidolite asbestos fibers. Con A and ricin, lectins that bind to mannose and galactose residues, respectively, did not block particle binding. When both positively charged iron spheres and negatively charged glass spheres were prebound to AM membranes, subsequent treatment with WGA displaced only the positively charged spheres from macrophage surfaces. Con A and ricin had no effect on prebound positively charged C-Fe and Al spheres.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of silica on the composition of the pulmonary extracellular lining

The effects of intratracheally injected silica on lung weights and on alveolar macrophages, polymorphonuclear leukocytes, phospholipid, protein, N-acetyl-beta-glucosaminidase, and alkaline phosphatase of the extracellular lining of rat lungs were studied as functions of dose and time. All of these parameters increased with time up to 12 days after a single injection of silica (200 mg/kg) and showed a dose dependence in their responses. Extracellular soluble protein increased 19.8-fold from 1.9 to 37.6 mg/pair of lungs. The composition of the extracellular soluble protein was very similar to that found in normal lungs as determined with two-dimensional-polyacrylamide gel electrophoresis. Although most of the soluble proteins in lavage effluents were similar to those found in serum, several serum proteins were absent, indicating that the selectivity of the lungs for certain serum proteins was maintained after treatment with silica. Increases in extracellular soluble proteins could not be accounted for by damage to the blood/air barrier. Extracellular phospholipid increased 12.1-fold from 1.74 to 21.1 mg/pair of lungs. The phosphatidylcholine content of this phospholipid resembled that of normal pulmonary surfactant but was different from that in free cells lavaged from the lungs of control and silica-treated rats. Increases in extracellular phospholipid were probably due to silica effects on the surfactant system and not to destruction of or release by free cells in the alveoli. N-Acetyl-beta-glucosaminidase and alkaline phosphatase increased approximately 33- and 6-fold, respectively, in response to silica. The number of alveolar macrophages and polymorphonuclear leukocytes increased 1.5- and 75-fold, respectively. Calculation of partial correlations revealed statistically significant relationships among extracellular phospholipids, soluble proteins, and the two hydrolytic enzymes, suggesting that these components were being released into the lung lining from a common source or by a common mechanism.

Outbreak of pulmonary tuberculosis in children

A case of miliary tuberculosis in a 4-year-old child led to contact tracing, revealing 32 children with evidence of tuberculous infection. 3 adult cases were also identified. The source case was a mother who passed on the infection at two Christmas parties. Limited exposure to the organism caused infection, suggesting a virulent strain and a susceptible subgroup. A range of complications of primary tuberculosis in children was seen. Minor side-effects of the chemotherapeutic agents occurred in most children but only 3 suffered substantial toxic effects. The limited range of agents marketed in a presentation suitable for young children was a serious difficulty.

Determination of Diagnostic Levels of Arsenic in Animal Tissue: Collaborative Study

The method chosen for this collaborative study is a modification of the AOAC method for As residues, 41.009-41.012. The tissue is dry-ashed overnight at 500°C, and then dissolved in dilute HCl. The solution is diluted and an aliquot is reacted with zinc metal to evolve arsine gas. The gas is trapped in AgDDC solution and As is quantitated at 540 nm. Nine collaborating laboratories performed single analyses on 4 blind duplicate pairs of bovine liver samples which were spiked at 0, 4.3, 10.8, or 21.6 mg As/kg liver. A National Bureau of Standards control (SRM 1566 Oyster Tissue, 13.4 ± 1.9 mg As/kg) and a 1000 mg As/L standard were also submitted to the collaborators. Intralaboratory coefficients of variation ranged from 7.7 to 17.8%; interlaboratory coefficients of variation ranged from 10.9 to 19.0%. The method has been adopted official first action.