Interrater reliability of roentgenological evaluation of the lumbar spine in lateral bending

Interrater reliability is described for the evaluation of lumbar motion and motion coupling patterns in lateral bending. Upright neutral and lateral bending lumbar films of 58 student volunteers were marked by three examiners. Segmental tilt, segmental rotation and motion categories were computed. The performance of the examiners was evaluated using the Kappa statistic and a comparison of rater discrepancy to the experimental measurement error. Although all three raters were proficient within the context of calculated measurement error, good reliability was not universally demonstrated. Concordance for rotation was moderate to good, while agreement for lateral bending was of questionable interpretation. Reliability for the segmental motion categories was good for L1-L4, but unacceptable at L5. The poor reliability at L5 resulted in unacceptable concordance for the lumbar global motion category for three raters. The use of lateral bending radiographs for categorization of the lumbar spine in clinical practice is questioned.

The physics of spinal manipulation. Part I. The myth of F = ma

The product of the adjusting physician's mass and acceleration does not quantify the adjustive force as popularly believed, an error stemming from a misunderstanding of Newton's second law. In this paper, a gedanken experiment illustrates the misapplication of F = ma and suggests that the adjustive force depends on the impact velocity, mass of the doctor, and intrinsic physical properties of the doctor and patient.

Calcium antagonists show two modes of protection in ischemic heart failure

Retrogradely perfused, isovolumically beating, paced rat hearts were subjected to 30 min of global ischemia in the absence and presence of nifedipine, verapamil, bepridil and quaternary bepridil at a concentration ranging from 3 to 10,000 nmol/l. Under constant pressure conditions, the arrest of coronary flow and the reduction of ventricular contraction during global ischemia were readily reversible and quickly returned at reperfusion. During ischemia, however, a diastolic contracture developed, which was slowly reversible upon reperfusion. The calcium antagonists studied appeared to delay and diminish in a concentration-dependent way the diastolic contracture during ischemia. Furthermore, they accelerated the reduction of this contracture at reperfusion. Nifedipine, bepridil and quaternary bepridil showed a 100 to 1000 times higher potency in accelerating the recovery of the diastolic contracture during the reperfusion phase than in reducing the development of diastolic tension during the ischemic period itself, whereas verapamil hardly discriminated these two phases. When the hearts were reperfused with nifedipine under constant flow conditions, reduction of the diastolic contracture during ischemia could still be observed, but the accelerated reduction of end-diastolic pressure during reperfusion was no longer present. The results are discussed in relation to the energy saving, negative inotropic activity of the drugs before the ischemic period and the strong coronary vasodilation, which seems to be involved in the protective activity of the drugs, especially during reperfusion.

Stereoisomers of calcium antagonists distinguish a myocardial and vascular mode of protection against cardiac ischemic injury

Concentration-dependent effects of the enantiomers of the calcium antagonists, gallopamil, diltiazem, and bepridil have been studied in the Langendorff-perfused rat heart, subjected to 30 min of global ischemia. It is shown that the time course, as well as the height of the energy deprivation-induced left ventricular diastolic contracture that develops during ischemia, can be selectively inhibited by negative inotropic concentrations of the calcium antagonist enantiomers. The time needed for recovery from the diastolic contracture during the reperfusion phase can be shortened significantly by lower, vasodilating concentrations of the drugs. In normoxically perfused hearts, stereoselectivity factors (sf) of the enantiomers of the compounds amounted to 63, 10, and 2 for the negative inotropic and 12.6, 79, and 4 for the vasodilating activities of gallopamil, cis-diltiazem, and bepridil, respectively. The sf values of negative inotropism proved to be remarkably similar to sf values of 50 and 7.9 for gallopamil and cis-diltiazem in the protection of the ischemic contracture during ischemia, whereas the sf values of coronary flow increase closely paralleled the values of 7.9, 63, and 2.5 for gallopamil, cis-diltiazem, and bepridil, respectively, in protection during the reperfusion phase. The results strongly suggest that at reperfusion the vasoselective enantiomers of calcium antagonists provide protection related to improved tissue perfusion, and thereby possibly restoring the distorted ionic and energetic homeostasis, whereas the other enantiomers are more involved in a direct energy-saving activity, resulting in protection during the ischemic period.

Homozygous deletion of the retinoblastoma gene in an acute lymphoblastic leukemia (T) cell line

Human leukemia cell lines were examined for the status of the retinoblastoma (RB) protein by immunoblotting analysis using antibodies raised against the TrpE-RB fusion protein. One of 16 cell lines examined, the T-cell acute lymphoblastic leukemia (ALL) line HSB-2, lacked the 110-Kd RB protein. Southern blot analysis of genomic DNA extracted from HSB-2 cells showed a large homozygous deletion of the RB gene, stretching from exon 18 beyond exon 27. Northern blot analysis showed multiple, abnormal RB transcripts in HSB-2. A truncated protein (72 Kd) was detected with 35S-methionine labeling but not with 32P-orthophosphate labeling of the HSB-2 cells. The genomic deletion of greater than 85 kb DNA at the RB locus (13q14) was not detectable in the karyotype of the HSB-2 cells. Among the 16 human leukemia cell lines examined for the status of the RB gene, only one, the HSB-2 line, showed an abnormal RB protein. Further study of primary leukemia and lymphoma samples appears to be warranted.

Protection by verapamil and nifedipine against ischaemia-induced loss of [3H]-(+)-PN 200-110 binding sites in the rat heart

We have studied the effects of 60 min global ischaemia and 30 min of subsequent reperfusion on the binding of [3H]-(+)-PN 200-110 and [3H]-(-)-devapamil (desmethoxyverapamil or D888) in rat heart membranes. The hearts were perfused in the Langendorff-mode and pretreated with 1 mumol/l verapamil, 30 nmol/l and 1 mumol/l nifedipine. After 60 min of global ischaemia in the absence of drugs, we found a reduction of [3H]-(+)-PN 200-110 binding sites, without changes in the equilibrium dissociation binding constant (Kd). After the subsequent reperfusion maximum specific binding (Bmax) was further reduced, whereas the Kd remained constant. [3H]-devapamil binding sites were influenced to a lower extend and showed only a decrease in Bmax at reperfusion. Pretreatment with 1 mumol/l verapamil completely prevented the changes which were observed for [3H]-(+)-PN 200-110. Pretreatment with a low, vasodilating concentration (30 nmol/l) of nifedipine displayed selective protection against the extra reduction in Bmax which was observed during reperfusion. It is concluded that calcium antagonists show protection against the ischaemia-induced loss of dihydropyridine binding sites in relation to their negative inotropic, energy-saving activity. Furthermore, nifedipine at low, vasodilating but not negative inotropic concentrations protects against further reperfusion-induced injury, which protection may be related to an improved flow during reperfusion.

Establishment of continuous cultures of T-cell acute lymphoblastic leukemia cells at diagnosis

We have devised methods facilitating the establishment of continuous cultures of T-cell blasts from patients with acute lymphoblastic leukemia of T-cell type at diagnosis. The cultured cells closely resemble those of the patients at the time of diagnosis with respect to surface markers, karyotype, and T-cell receptor gene rearrangements. Cultured T-cell acute lymphoblastic leukemia (diagnosis) cells (a) are lymphocytes with a convoluted nucleus; (b) have doubling times of 24-48 h; (c) are dependent for growth on interleukin 2; (d) are reverse transcriptase negative; (e) do not form colonies in methyl cellulose; and (f) are clonal with respect to T-cell receptor beta chain rearrangements. Three T-cell acute lymphoblastic leukemia cultures had a normal diploid karyotype, and one had a 6q- deletion which was also present at the time of diagnosis.

Skin blade versus deep blade: a vehicle of contamination in podiatric surgery

A total of 166 surgical blades consisting of control blades, skin blades, and deep blades were cultured from 50 elective podiatric surgical cases. Five blades from four cases cultured Staphylococcus epidermidis. The practice of changing from skin blade to deep blade to reduce contamination of a clean surgical wound is not supported by the data obtained in this study.

Discrepancies in lipolytic activities induced by beta-adrenoceptor agonists in human and rat adipocytes

A number of catecholamine and non-catecholamine beta-adrenoceptor agonists, including the lipolytically selective compound BRL 37344, were compared for lipolytic activity on human and rat adipocytes. On rat adipocytes, all compounds were full agonists, BRL 37344 being the most potent. On human adipocytes, only the catecholamines were full beta-adrenoceptor agonists. The other compounds were partial agonists, with intrinsic activities declining in the order fenoterol greater than salbutamol greater than clenbuterol greater than BRL 37344. This was the case with FFA- as well as with glycerol-production. Addition of 20 microM phentolamine did not enhance BRL 37344 activity. The isoprenaline- and BRL 37344-induced lipolysis on rat white adipocytes was stereoselectively antagonized by enantiomers of alprenolol, with atypical low potencies and stereoselectivity. It was concluded that (1) human and rat adipocyte beta-adrenoceptors mediating lipolysis are not essentially different, (2) partial agonism in human adipocytes is not explained by enhanced re-esterification and (3) BRL 37344 selectively stimulates rat adipocyte lipolysis.

The system of prosthetic treatment for CLAP patients

The prosthetic treatment of CLAP patients is usually done in three phases: an interceptive treatment during two stages of orthodontics, the definitive prosthetic treatment and usually the secondary treatment. In the interceptive phase we use clasp-retained partials; the definitive treatment is achieved mostly by telescope-retained partials. There is seldom an indication for Maryland-bridges or for dental implants.

[Periodontal aspects of removable partial dentures]

Periodontal pre-treatment of patients receiving partial dentures should involve three phases: initial therapy; periodontal surgery; home care. For periodontal surgery and/or prosthodontic treatment using precision materials, e.g. telescope retainers, the API (approximal plaque index) should not exceed 30%. To prevent further loss of gingival attachment due to iatrogenic irritation by the dentures preparation of abutments should consistently the para- or supragingival. In patients with few residual teeth telescope retainers, which can be cemented for definitive fit if indicated, are the treatment of choice.

[Periodontal aspects of care of partially edentulous jaws]

After an initial periodontal therapy to reduce bleeding a pocket depth and after reaching an AOI below 30% it is possible to make an apical reposition-flap. It is apt to supragingivalize the margins of restorations of fractured teeth or in case of subgingival lesions or preparation margins. In combination with a good recall-system thus the prognosis of periodontal treatment can be optimized.

Enterobacter sakazakii infections in neonates associated with intrinsic contamination of a powdered infant formula

We report an outbreak of Enterobacter sakazakii infection and colonization in neonates related to an infant formula contaminated during the manufacturing process. The outbreak occurred in a 20-bed neonatal intensive care unit during a six-week period in 1988, and involved a total of four infants. Three infants had sepsis and three had bloody diarrhea; all patients responded to intravenous antibiotics and recovered without complications. The E sakazakii isolated from the formula had the same plasmid and multilocus enzyme profile as those isolated from patients. This outbreak demonstrates the significance of commercially contaminated formulas and emphasizes the need to limit contamination and multiplication of bacteria in enteral formulas.

Effects of verapamil on ischaemia-induced impairment of ATP-dependent calcium extrusion in rat heart sarcolemma

1. The effects of ischaemia and reperfusion were studied on adenosine 5'-triphosphate (ATP)-dependent 45Ca2+-transport in rat heart sarcolemma vesicles. 2. The effect of verapamil, 1 mumol l-1, was studied by pretreatment of the hearts during Langendorff-perfusion and in vitro by adding the drug after isolation of the vesicles. 3. Without drug pretreatment the Ca2+-uptake appeared to be strongly reduced after 30 and after 60 min of global ischaemia, whereas after 30 min of reperfusion it was restored to slightly above the control level. 4. Verapamil pretreatment during the Langendorff perfusion significantly increased Ca2+-uptake in sarcolemma vesicles both before the onset of ischaemia and after 30 min of reperfusion, whereas no beneficial effect was found on the impaired uptake activity during the ischaemic period. 5. When tested in vitro after the isolation of the sarcolemma vesicles, verapamil only inhibited the Ca2+-uptake activity with an IC50 of 112 mumol l-1, which was increased to 250 mumol l-1 after ischaemia and reperfusion. 6. The present study indicates that pretreatment with verapamil, 1 mumol l-1, of the intact rat heart activates an ATP-dependent Ca2+ extrusion process that may contribute to decrease cellular calcium levels in control and, more importantly, in a reperfusion situation. In contrast, in vitro only a less potent inhibition of the extrusion process was found, indicating that physiological regulatory mechanisms may be altered in the vesicles.

Stereoisomers of BAY K 8644 show opposite activities in the normal and ischaemic rat heart. A comparison with nifedipine

The effects of the stereoisomers and the racemate of the calcium agonist BAY K 8644 and the calcium antagonist nifedipine were studied on the Langendorff-perfused rat heart, subjected to 30 min of global ischaemia. The results show that (-)- and (+/-)-BAY K 8644 induced a strong positive inotropic effect at 100 and 1000 nmol/l and a vasoconstricting effect which was most prominent at 1 and 10 nmol/l, respectively. At higher concentrations the flow reduction was inverted to a flow increase, closely related to the positive inotropic activity. The inotropic status induced by the agonist before the onset of ischaemia was reflected in an accelerated development of the diastolic contracture during ischaemia. During the reperfusion, a complex triphasic effect on the recovery was found, in which probably positive inotropism, vasoconstriction, metabolic and mechanical factors are involved. The (+)-enantiomer of BAY K 8644 behaved as a weak calcium antagonist showing merely vasodilatation, which accelerated the recovery from the ischaemic contracture at reperfusion. The calcium antagonistic, vasodilating effects of the (+)-enantiomer were expressed in the racemate only during the reperfusion phase, where it took an intermediate position between the effects of the (-)- and (+)-enantiomer. In contrast, nifedipine, at negative inotropic - energy saving - concentrations, diminished the height and delayed the development of the energy deprivation-induced left ventricular diastolic contracture during ischaemia. The time needed for recovery from the contracture during reperfusion was significantly shortened already at a 100 times lower, vasodilating concentration of nifedipine.

[Bonded porcelain laminates--an alternative to anterior porcelain crowns]

The trend towards esthetic dentistry, which originates in the USA, has added new dimensions to the treatment of anterior teeth. One of it is the porcelain laminate technique. Using composites, extremely thin, manually prepared porcelain laminates with a thickness of 0.3 to 0.5 mm are bounded to the labial aspect of front teeth or laterals. On account of the low laminate thickness very little enamel preparation is needed. The residual enamel mass and the translucency of the ceramic material produce a natural appearance and optimal cosmetic results. This technique enables the dentist to restore the shape and color of esthetically compromised teeth.

The need for a search for a proximal pathogenic principle of human AIDS

Some of the unexplained aspects of HIV/AIDS epidemiology, virology, and pathology (6, 13) may thus be due to a lack of knowledge of the basic virology of the virus complex and its pathological interaction with cells of the host. There may be no need to call upon anomalous immune responses, vicious transactivating activities, or new virological or biological principles if we can first do the basic virology of the disease-inducing viruses. While we do not want to propose that working out the virology will by necessity be easy on all counts, it may lead us all to more equitable immunological, pathological, and cell biological approaches to this formidable problem. A fine beginning has been made by Fisher et al. (10), Saag et al. (11), and others. To retrovirologists the problems appear not to be insurmountable.

Stimulation of K-C1 cotransport in rat red cells by a hemolytic anemia-producing metabolite of dapsone

Dapsone, a sulfone compound used in the treatment of leprosy and, more recently, Pneumocystis carinii pneumonia, produces as a major side effect a hemolytic anemia. This anemia is characterized by oxidation of hemoglobin to methemoglobin and increased splenic uptake of red blood cells. Using a rat model, Grossman and Jollow (J. Pharmacol. Exp. Ther. 244: 118-125, 1988) found that dapsone hydroxylamine (DDS-NOH), a dapsone metabolite, is responsible for its hemolytic effect in vivo. DDS-NOH also promotes hemoglobin binding to SH groups on rat red cell membrane proteins (Budinsky et al., FASEB J. 2: A801, 1988). Since the binding of hemoglobin and other reagents (e.g., N-ethylmaleimide) to membrane SH groups has been associated with increased K transport in red blood cells, we examined the effect of DDS-NOH on K efflux from rat red blood cells in vitro. Cells shrink when exposed to DDS-NOH (100 microM) in media with plasma-like ionic composition. This shrinkage is prevented if extracellular K is raised to 110 mM or if intra- and extracellular Cl are replaced by methylsulfate (MeSO4), suggesting involvement of a K-Cl cotransport pathway. Indeed, 100 microM DDS-NOH produces a 4- to 5-fold increase in K efflux in cells containing Cl but less than a 2-fold increase in cells containing MeSO4. This stimulatory effect is specific for K; Na efflux is slightly inhibited by 100 microM DDS-NOH. The concentrations of DDS-NOH required for half-maximal stimulation of Cl-dependent K efflux (53 microM) is similar to its half-maximal hemolytic concentration in rats (approximately 100 microM). Furthermore, the stimulation of Cl-dependent K efflux by DDS-NOH is greater than 80% reversed by subsequent treatment of the cells with dithiothreitol, suggesting involvement of SH groups. Our results indicate that DDS-NOH exposure stimulates an apparent K-Cl cotransport in rat red blood cells, resulting in cell shrinkage under physiological ionic conditions. Since shrinkage of red blood cells renders them less deformable (Mohandas et al., J. Clin. Invest. 66: 563-573, 1980), this suggests a pathophysiological mechanism whereby DDS-NOH exposure in vivo could promote increased splenic uptake of red blood cells and hemolytic anemia.

Cation-anion cotransport

Two methods have been described for the study of cation-chloride cotransport systems. The zero-trans efflux method is designed to determine stoichiometric relationships between cotransported ions under conditions where ion exchanges cannot occur. These exchanges (e.g., Na+/Na+, K+/K+) may occur as partial or incomplete reactions of a cotransport process and can lead to erroneous determinations of the stoichiometry of the cotransport process. The zero-trans efflux method can also be used to study the effects of cell volume, pH, and intracellular ion concentrations on cotransport processes. The valinomycin method is used to determine the electrogenicity or electroneutrality of transport, and in this regard can be used in conjunction with other methods such as those employing potential-sensitive dyes or microelectrodes. Other, more recently developed ionophores with specificity for lithium rather than potassium have now been used to study the effect of Em on the ATP-dependent Na+/K+ pump. It may be possible to use such ionophores to confirm the suspected electroneutrality of (K+ + Cl-) cotransport systems, as well as for other studies of specific potassium transport processes in which valinomycin obviously cannot be used. Both methods discussed in detail in this chapter, and particularly the valinomycin method, were originally devised for use in red blood cells in order to take advantage of (or circumvent) properties of the red cell membrane, such as its low permeability to sodium and potassium and relatively high permeability to chloride. However, valinomycin has been used successfully to demonstrate the electroneutrality of (Na+ + K+ + 2Cl-) cotransport in MDCK cells, and the zero-trans efflux method should be applicable to the study of transport processes in other types of cells in suspension, so long as the transport system being studied can be accurately defined (e.g., as an inhibitor-sensitive or chloride-dependent cation flux) and comprises a significant fraction of the total salt efflux.