Comparative quantitative analysis of sucrose and related compounds using ion exchange and reverse phase chromatographic methods

Two analytical methods of sugar determination, namely ion exchange chromatography on an anionic resin coupled with electrochemical detection, and reverse phase chromatography on Nucleosil-NH2 resin equipped with a light scattering detector were tested and compared as regards their rapidity, sensitivity and accuracy with sucrose, fructose, glucose, raffinose, maltose, arabinose, fucose, rhamnose and xylose. Excellent resolution and highly reproducible results were obtained in both cases. Greater sensitivity up to the picomolar range was possible however only with ion exchange chromatography. Reverse phase chromatography was successfully applied to the time course of sucrose hydrolysis under chemical (acid) and enzymatic (invertase) conditions. The hydrolysis was monitored by determining sucrose degradation and the corresponding formation of glucose and fructose.

Multicomponent acoustic distortion product otoacoustic emission phase in humans. I. General characteristics

Phase characteristics and latency of 2f1-f2, 3f1-2f2, and 2f2-f1 acoustic distortion product otoacoustic emissions (DPOAEs) have been analyzed in 12 adults with normal hearing. Phase-versus-frequency functions (PFF) have been recorded at each of ten pairs of primary frequencies, by two methods, depending on which one of the primary frequencies f1 or f2 was swept in frequency. Whichever sweep method was used, local phase irregularities were found in the PFF and were shown to be independent of the phase variability due to the measured noise, to be reproducible and frequency specific. Phase irregularities were significantly greater in subjects exhibiting spontaneous otoacoustic emissions. The latency calculation was unaffected by phase irregularities provided that a suitably large range of f2/f1 ratio was used. The DPOAE latencies that were obtained at low ratios of primaries were significantly longer than those obtained at higher ratios. For all DPOAE components and sweep methods used, the latency decreased as frequency increased from 750 Hz to 6 kHz. Substantial intersubject differences were found. They might be due to two main factors: differences in middle ear acoustic properties and in cochlea mechanical characteristics. The influence of pressure in the outer ear canal increased the DPOAE latencies recorded with both the f1 and f2 sweep methods at low frequencies. Men showed significantly longer 2f2-f1 DPOAE latencies than women, especially at low frequencies, which can be attributed to the difference in length of the cochlea according to gender. Lastly, the latencies measured using the f2 sweep were consistently longer than the latencies obtained using an f1 sweep for lower sideband DPOAEs, but no difference was observed for upper sideband DPOAEs.

Multicomponent acoustic distortion product otoacoustic emission phase in humans. II. Implications for distortion product otoacoustic emissions generation

Phase characteristics and latency of 2f1-f2, 3f1-2f2, and 2f2-f1 acoustic distortion product otoacoustic emissions (DPOAEs) recorded in normally hearing adults have been described in a companion paper [Moulin and Kemp, "Multicomponent acoustic distortion product otoacoustic emission phase in humans. I. General characteristics," J. Acoust. Soc. Am. 100, 1617-1639 (1996)]. Phase-versus-frequency functions (PFF) have been recorded using two methods, depending whether f1 or f2 was swept in frequency, defining, respectively, an "f1 sweep" and an "f2 sweep" method. The present study compares 2f1-f2, 3f1-2f2, 4f1-3f2, and 2f2-f1 DPOAEs phase characteristics, and latencies obtained by these two methods. For lower sideband DPOAEs, the f2 sweep gave consistently longer latencies than the f1 sweep method, whereas no difference was obtained for the 2f2-f1 DPOAE. This suggests that the lower sideband DPOAEs and the 2f2-f1 DPOAE do not come from the same aspect of the traveling wave. The longer delay obtained with an f2 sweep is suggested to be due to an additional delay added by the proximity of the peak of the f2 traveling wave. The place-fixed and the wave-fixed models of DPOAE generation are discussed, and an "intermediate" model of DPOAE generation is introduced to explain such additional delay and the existence of phase irregularities which were observed in the PFF. The ratio of the latencies obtained by the two sweep methods is frequency dependent and a relation to cochlear frequency selectivity is suggested. Finally, analysis of the differences in latency of the different lower sideband DPOAE components allowed an estimation of the return latency of DPOAEs.

Lipases of the euphorbiaceae family: purification of a lipase from Euphorbia characias latex and structure-function relationships with the B chain of ricin

A lipase from the latex of Euphorbia characias was purified using a method involving extraction with apolar solvent and adsorption chromatography on silica gel. The lipase (specific activity, 1500 international units/mg of protein) was eluted from silica gel complexes with a lipid. The main protein fraction, which had a molecular mass of 38 kDa, was inactive when dissociated from the lipid fraction. When the lipid and protein fractions were reassociated, 72% of the lipolytic activity was recovered. This lipolytic activity was inhibited by diethyl p-nitrophenyl phosphate, which was shown to bind the lipase with a molar ratio of 0.75. High specific activities (1000 international units/mg) were measured for the lipase of E. characias on lipid extracts rich in galactosyl diacylglycerols. The apolipase was sequenced up to residue 23. The B chain of ricin has a strong homology (43.5%) with that sequence and cross-reacted with antibodies raised against the purified lipase from E. characias. The activity of the B chain of ricin was comparable (54 international units/mg) to that of the apolipase of E. characias (100 international units/mg) mixed with the same lipid cofactor complex. The primary structure (residues 68-72) of the B chain of ricin contains the lipase consensus sequence Gly-Xaa-Ser-Xaa-Gly. Its reactivity with diethyl p-nitrophenyl phosphate indicates the presence of an activated serine that, in addition to its well-documented lectin activity for galactosides, suggests that the B chain of ricin may be a galactosyl diacylglycerol lipase, closely analogous to the lipase from E. characias.

Distortion product otoacoustic emissions and sensorineural hearing loss

As other types of otoacoustic emissions, distortion product otoacoustic emissions (DPOAEs) allow the exploration of the active cochlear mechanisms known to take place in the outer hair cell system. Most authors consider that 2f1-f2 DPOAEs are generated in a cochlear region corresponding to the geometric mean (GM) of the primary frequencies. To verify the relevance of this hypothesis in clinical practice, DPOAEs were recorded at seven different frequencies, ranging from 0.5 to 4 kHz, in 81 hearing-impaired patients and in 24 normally hearing subjects. To test the hypothesis that DPOAEs reflect the hearing threshold at the frequency of the GM rather than at the 2f1-f2 frequency, this study compares the 2f1-f2 frequency and the GM of the primaries to the frequency of hearing loss. DPOAEs can be used to explore a large range of frequencies, especially at high frequencies, but responses at low frequencies are less reliable due to noise contamination. Secondly, DPOAEs can be recorded in ears that have a hearing threshold as high as 65 dB HL at the frequency corresponding to the GM of the primaries. Finally, DPOAE recordings show frequency specificity: i.e., hearing loss at a specific frequency correlates best with DPOAEs whose GM of primary frequencies corresponds to the frequency of the hearing loss. However, this frequency specificity is still unsatisfactory and decreases as the levels of primaries increase above 60 dB SPL. Moreover, DPOAE amplitude is too variable to predict hearing loss at a particular frequency, whereas DPOAE threshold allows a correct prediction of abnormal auditory threshold in more than 80% of the cases at frequencies above 1 kHz.

High-performance liquid chromatographic determination of oxodipine enantiomers, a new 1,4-dihydropyridine, applied to stereoselectivity studies in man and dog

A specific and reproducible HPLC method using a Chiral-AGP column and UV detection was developed for the evaluation of the pharmacokinetic profile of oxodipine enantiomers in dog and man. Each enantiomer was determined in plasma in the concentration range 1-400 ng/ml using the internal standard calibration method with linear regression analysis. After extraction of oxodipine and the internal standard at alkaline pH with diethyl ether-n-hexane (50:50, v/v), this method permitted the determination of each enantiomer at levels down to 10 ng/ml in dog plasma and 25 ng/ml in human plasma with sufficient accuracy (relative error < 11%, n = 6) and precision (coefficient of variation < 16%, n = 6). The extracted plasma volume was 500 microliters and after evaporation of the organic phase, the dry residue was dissolved in 100 microliters of water-2-propranol; an aliquot of 80 microliters was injected into the HPLC system.

Contralateral auditory stimulation and otoacoustic emissions: a review of basic data in humans

The influence of contralateral auditory stimulation on otoacoustic emissions (OAE), spontaneous OAE, evoked OAE and acoustic distortion products, can be summarized as follows: (1) alteration (mainly a decrease) of OAE amplitude; (2) alteration of response spectrum (upward shift frequency of SOAE); (3) alteration of phase; (4) effect dependent on intensity of contralateral stimulation; (5) effect inversely dependent on intensity of ipsilateral stimulation; (6) frequency specificity of the suppressive effect. Involvement of the medial olivocochlear bundle is highly probable but one cannot exclude a double pathway including also the acoustic reflex.

Is the test of medial efferent system function a relevant investigation in tinnitus?

The present results are drawn from preliminary observations made in 28 patients suffering from unilateral, permanent, non-pulsatile tinnitus, who were systematically submitted to an investigation of their otoacoustic emissions in both ears. Spontaneous otoemissions (SOAE) were carefully looked for, before recording of transient evoked otoemissions (TEOAE). The effectiveness of the medial olivo-cochlear efferent system (MOC) was also tested. The comparison between TEOAE input/output curves obtained with and without contralateral stimulation allowed a global assessment of the functioning of MOC. Additional information relating to the MOC functioning at the precise frequency of tinnitus and/or around it, was available from the comparison of analogous curves obtained using distortion product otoacoustic emissions (DPOAE) instead of TEOAEs. The results show that: (1) when the amplitude of otoacoustic emissions differs between the two ears, the tinnitus is generally lateralized on the side where amplitude was the lowest, which seems to be related to a greater hearing loss; (2) no general law concerning tinnitus can be drawn from the global testing of MOC functioning; the only result is that the slope of TEOAE input/output function appears as a deciding factor for efficiency of MOC, the least efficiency almost always occurring on the side where the slope is greater, and (3) even in the case of proved global effectiveness of MOC activation, there is, at least in the vicinity and in at least one ear, a part of the cochlea where its functioning is altered. A better comprehension of the mechanisms underlying this symptom will probably come from exhaustive exploration of individual cases rather than a rougher investigation of large samples in which different aetiologies are likely to be mixed.

Evoked and spontaneous otoacoustic emissions. A comparison of neonates and adults

Evoked otoacoustic emissions (EOAEs) and spontaneous otoacoustic emissions (SOAEs) were compared between neonates and adults. Several differences were seen for EOAEs: (i) the occurrence of EOAEs was significantly greater in adults than in neonates, and in neonates it increased with extra-uterine age; (ii) the high frequency EOAE intensity was greater in neonates than in adults; (iii) the EOAE intensity was significantly greater in neonates than in adults. No age-related differences for SOAEs were found: (i) age was not significantly related to the presence/absence of SOAEs in neonates or adults; (ii) the occurrence of SOAEs was, however, significantly greater in females than in males in both neonates and adults.

Effect of contralateral sound stimulation on the distortion product 2f1-f2 in humans: evidence of a frequency specificity

The frequency characteristics of the suppression by contralateral stimulations, of the cubic 2f1-f2 distortion products (DPOAEs), were studied during 63 sessions performed in 39 humans with normal hearing. Each session consisted of exposure to five successive series of randomized contralateral NBN frequencies centered between 0.25 and 8 kHz, while measuring 2f1-f2 set at one of the four studied frequencies, i.e., 1, 2, 3 or 5 kHz. For each value of 2f1-f2, analysis of variance and Student's t-test were used in order to indicate and, if necessary, to localize, a possible significant frequency specificity. Results showed that the suppression exerted on 2f1-f2 DPOAEs by contralateral sound stimulation, is frequency specific, at least for middle frequencies of 1 and 2 kHz. The frequency specificity is specially marked when 2f1-f2 = 1 kHz with contralateral NBN central frequencies around 1 kHz. When 2f1-f2 = 2 kHz, central frequencies which induced a significant suppressive effect include frequencies around 2 kHz and also lower frequencies around 1 kHz. These observations support the interpretation that the suppression of the DPOAE is mediated by the medial olivo-cochlear efferent system.

Interrelations between transiently evoked otoacoustic emissions, spontaneous otoacoustic emissions and acoustic distortion products in normally hearing subjects

Active cochlear mechanisms and especially outer hair cells seem to be involved in oto-acoustic emissions (OAEs) genesis. This study sought to investigate basic characteristics of spontaneous otoacoustic emissions (SOAEs), click-evoked otoacoustic emissions (TOAEs) and interrelations between SOAEs, TOAEs and 2f1-f2 and 2f2-f1 distortion product OAEs (DPOAEs) in 135 normally hearing subjects. A gender effect was shown on TOAEs and DPOAEs amplitude, and is attributed to the higher incidence of SOAEs in women (58%) than in men (22%). Moreover, SOAEs presence seems to mask the age effect found, especially at high frequency components, on TOAEs amplitude. A general influence of SOAEs on TOAEs and DPOAEs is shown, especially at frequencies ranging from 1 kHz to 3 kHz, collecting more than 66% of the SOAEs peaks recorded. Lastly, correlations between TOAEs frequency band amplitude and 2f1-f2 DPOAEs amplitude, shows frequency specificity, at least at low frequencies (i.e., from 0.5 to 2 kHz) in agreement with previous works suggesting that the 2f1-f2 DPOAEs generation site is at the geometric mean of the primaries. The same correlations calculated with 2f2-f1 DPOAEs amplitude show frequency specificity at low frequencies i.e., at 800 Hz and 1600 Hz. 2f2-f1 DPOAEs in humans are shown to be generated near the 2f2-f1 frequency region on the cochlear partition.

Contralateral auditory stimulation alters acoustic distortion products in humans

It is now generally accepted that otoacoustic emissions (OAE) represent the only objective and non-intrusive means of functional exploration of the active micromechanical characteristics of the outer hair cells of the organ of Corti. Previous studies showed a decrease of the transiently evoked otoacoustic emissions and spontaneous otoacoustic emissions in humans, during acoustic stimulation of the contralateral ear, and attributed this effect to the medial efferent system. Such an effect has been shown on acoustic distortion product otoacoustic distortion emissions (DPOAE) in guinea pigs, but has not been investigated for DPOAEs recorded in humans, although DPOAEs represent the easiest means of exploring active micromechanical cochlear properties both in humans and in laboratory animals. The present study sought to investigate the existence and characteristics of a contralateral auditory stimulation effect on DPOAEs recorded in humans. This study shows that contralateral broad-band noise (BBN) has a suppressive effect on DPOAEs recorded from 0.5 kHz to 5 kHz. This effect is not due to air conduction, as no change in the noise floor occurred under increasing contralateral stimulation, and as no reduction in DPOAE amplitude was obtained in subjects whose contralateral ear was sealed with a plastic ear plug. Moreover, cross-over attenuation by bone transmission has been ruled out, as no change in DPOAE amplitude was recorded in the healthy ear of total unilaterally deaf patients during acoustic stimulation of the deaf ear. The effect seen was not entirely due to the acoustic reflex, as it was found and could indeed be even greater in subjects with no acoustic reflex. Results presented here show that the contralateral BBN effect is greater at low levels of ipsilateral stimulation, which leads us to discuss the involvement of both passive and active mechanisms in DPOAE generation at high stimulation levels. The contralateral BBN effect seems to be greater in mid frequency cochlear regions. There is strong evidence that the medial efferent system is involved and that afferent and efferent inputs are, at least partly, integrated at a brainstem level in order to ensure cochlear interaction. DPOAEs provide an interesting model for functional exploration of the efferent system, since they seem to be the only type of otoacoustic emission that can be recorded in both humans and in the majority of animals, and since results are obtained in the same way from both animals and humans, which allows experimental animal models very close to the human model.

Influence of spontaneous otoacoustic emissions (SOAE) on acoustic distortion product input/output functions: does the medial efferent system act differently in the vicinity of an SOAE?

Otoacoustic emission (OAE) generation mechanisms reside in the active micromechanical properties of the organ of Corti, and especially in the outer hair cells (OHCs). OHCs are strongly innervated by medial efferent olivo-cochlear fibres. Decrease of the intensity of transiently evoked otoacoustic emissions (TOAEs) and modification of spontaneous otoacoustic emissions (SOAEs) during acoustic stimulation of the contralateral ear have already been shown in humans. Similar results were obtained in guinea pigs with a decrease of 2F1-F2 acoustic distortion products (DPOAEs) and a suppression of the effect with sectioning of the floor of the fourth ventricle. The present study sought to investigate the influence of contralateral auditory stimulation on DPOAEs recorded in humans. It shows a decrease in DPOAE intensity for all frequencies, at levels above 45 dB SPL of contralateral broad band noise. This effect was found at levels of contralateral BBN well below the acoustic reflex threshold, and in subjects without acoustic reflex. Moreover, the influence of transcranial transmission could be ruled out since no effect was found when contralateral BBN applied to the altered ear of totally unilaterally deaf patients. Thus, the contralateral acoustic stimulation effect on DPOAEs provides a new means of functional exploration of the medial efferent system in humans. The effect obtained is more ample at low primary frequency levels. Moreover, as DPOAEs are known to be stronger and to show more irregular input/output function patterns in the vicinity of an SOAE, the influence of contralateral auditory stimulation was studied for DPOAEs recorded at 10 Hz, 50 Hz and 150 Hz from an SOAE frequency.

Inactivation of gastric and pancreatic lipases by diethyl p-nitrophenyl phosphate

Reacting gastric and pancreatic lipases with mixed diethyl p-nitrophenyl phosphate/bile salt micelles resulted in a stoichiometric inactivation of these enzymes as tested on emulsified tributyroylglycerol and trioleoylglycerol as substrates. Diethyl p-nitrophenyl phosphate treated gastric lipases were also inactive on water-soluble p-nitrophenyl acetate, whereas the modified pancreatic lipase was still able to hydrolyze this water-soluble substrate. The binding of diethyl p-nitrophenyl phosphate modified pancreatic and gastric lipases to tributyroylglycerol/water interface was comparable to that of native lipases. The essential free sulfhydryl group of gastric lipases underwent no chemical changes due to the reaction with micellar diethyl p-nitrophenyl phosphate. All in all, these results indicate that, in both gastric and pancreatic lipases, the essential serine residue which was stoichiometrically labeled by this organophosphorus reagent is involved in catalysis and not in lipid binding.

Spontaneous otoacoustic emissions and sensori-neural hearing loss

This study sought to clarify the clinical relevance of spontaneous otoacoustic emissions (SOAEs) and to define the hearing loss level (and frequency) at which absence of SOAE is found. Findings from 126 ears of patients with sensori-neural hearing loss showed an incidence of SOAEs in 18.25% of the cases (23 out of 126 ears). SOAEs were never found when hearing loss at 1,000 Hz exceeded 10 dB. The presence of SOAE seems to indicate a good cochlear functioning at least in the mid-frequencies. Although the incidence of SOAEs is markedly lower than that of evoked otoacoustic emissions (EOAEs), SOAE recording is shown to be a good test, rapid, non-invasive for audiological screening, the presence of SOAE confirming a hearing threshold of less than 10 dB at 1,000 Hz, the absence of SOAE being inconclusive.

Age-related changes in evoked otoacoustic emissions

Outer hair cells of the organ of Corti play an important part in the genesis of evoked otoacoustic emissions (EOAEs), which are related to cochlear biomechanics. The aim of this study was to investigate the age factor in relation to EOAEs in 166 ears of subjects between 6 weeks and 83 years of age. The results show that when age increases, the presence of EOAEs by age group and the frequency peak in spectral analysis decrease, and EOAE threshold increases. Thus, there is an effect of age upon EOAEs, and it seems linked with alteration of cochlear biomechanics and/or hair cell loss. Such an effect has to be taken into consideration when EOAEs are used in clinical applications, and limits the use of EOAEs in older subjects.

High-performance liquid chromatographic determination of 4-amino-5-chloro-N-[(1-ethylimidazolin-2-yl)methyl]-2-methoxybenzamide and its metabolite in biological fluids. Applications in pharmacokinetic studies

A high-performance liquid chromatographic method with spectrofluorometric detection has been developed for the analysis of a new substituted benzamide and its metabolite in body fluids. The detection was performed at 270 nm for excitation, and 370 nm for emission. The proposed technique is selective, reliable, and sensitive. The detection limit is 1 ng/mL for the parent drug and 2 ng/mL for the imidazole derivative. The reproducibility of the analytical method through statistical coefficients is approximately 5%. The accuracy of the method is good; that is, the relative error is less than 2%. To validate this method, the stability of these two drugs was tested at the time of conservation of urine and plasma samples and during all steps of the analytical method.

Effect of contralateral auditory stimuli on active cochlear micro-mechanical properties in human subjects

The present study investigates the possibility that contralateral auditory stimulation along medial efferent system pathways may alter active cochlear micromechanics and hence affect evoked oto-acoustic emissions in humans. A first experiment, involving 21 healthy subjects showed reduction of oto-acoustic emission amplitude under low intensity contralateral white noise (from 30 dB SPL, 10 dB SL, upwards). The effect is found for intensities below the acoustic reflex threshold (85.2 dB HL). A second experiment, involving 10 of the above 21 subjects, sought to rule out any technical artefact. Recording was again carried out, but after sealing of the contralateral ear with a silicon putty plug. No contralateral intensity effect on oto-acoustic emission amplitude was found for contralateral intensities below 65 dB SPL. In subjective perception terms (dB SL) an effect was found under sealing when the sound reached or passed above the 10 dB SL level. These two findings confirm the preceding experiment. The third experiment investigated the role of transcranial transmission of the contralateral auditory stimulus. 16 subjects having total unilateral deafness and one healthy ear were tested by the same procedure as above. No fall-off in oto-acoustic emission amplitude was found for contralateral stimuli equal to or less than 80 dB SPL. There is thus a contralateral auditory stimulus effect on active cochlear micromechanics. The most appropriate explanation involves the medial cochlear efferent system, excited at brainstem level via the afferent auditory pathways. Alteration of active cochlear micromechanics seems promising at a basic level, pointing, as it does, to an interactive cochlear functioning which can be investigated by simple, non-intrusive, objective techniques which can be used with human subjects. We have here a model for functional exploration of the medial olivocochlear efferent system.

Evoked otoacoustic emissions and sensorineural hearing loss

Following Kemp's original studies, several others have confirmed the existence of otoacoustic emissions. Their clinical relevance remains, however, to be clarified. The various published studies have concerned small series. This study sought to specify otoacoustic emission characteristics in relation to sensorineural hearing loss (148 ears of 76 subjects). The results show that the presence of otoacoustic emissions drops as a function of hearing loss and that there is a highly statistically significant correlation between otoacoustic emission threshold and hearing loss at the 1000-Hz frequency. Otoacoustic emissions are never found when hearing loss at 1000 Hz exceeds 40 dB hearing level and when the mean audiometric hearing loss (at 500, 1000, 2000, and 4000 Hz) exceeds 45 dB hearing level. The main practical conclusion is that otoacoustic emission presence indicates middle frequency functional integrity of the outer hair cells of Corti's organ. Absence of otoacoustic emissions is harder to interpret.

Interface-mediated inactivation of pancreatic lipase by a water-reactive compound: 2-sulfobenzoic cyclic anhydride

2-Sulfobenzoic cyclic anhydride (SBA) rapidly and selectively inactivates porcine pancreatic lipase (PPL) only when added during the hydrolysis of an emulsified ester such as tributyrin or dodecyl acetate. The present data suggest that the inactivation of PPL occurs preferentially at the oil/water interface and not in the aqueous phase, since colipase and bile salt were found to adversely affect the inhibition process. Moreover, it is shown that at a molar ratio of SBA to pure PPL of 1, 40% of the lipase activity was already irreversibly lost. Complete inactivation was observed at SBA to pure PPL molar ratios of 120. A 60% inactivation occurred when 0.5 mol of 3H-labeled SBA was attached per mole of PPL. The SBA-inactivated PPL competes for binding to the dodecyl acetate/water interface as efficiently as the native enzyme. Larger SBA concentrations are required when crude lipase preparations are used as well as with pure PPL in the presence of bile salts and colipase. Lipases were found to have variable sensitivities to SBA inactivation, depending on their origin. In the presence of bile salts and tributyrin at pH 6.0, human gastric lipase activity was not affected by the presence of a 10(6) molar excess of SBA.

Pharmacokinetics and metabolism of the anti-arrhythmic carocainide in man

The pharmacokinetics and metabolism of the anti-arrhythmic drug carocainide have been investigated in six healthy adult volunteers following single 100 mg intravenous and oral doses. Carocainide was labelled with 14C in the benzofuran ring. After i.v. administration, plasma concentration/time decay of carocainide was triexponential. Mean plasma elimination half-life of the drug was 5.0 +/- 2.2 h (i.v.) and 5.4 +/- 1.1 h (p.o.). Carocainide was virtually completely absorbed after the oral dose. The drug was eliminated mostly as unchanged drug in urine by the two routes of administration. There was some evidence that carocainide underwent enterohepatic cycling. Binding of carocainide to plasma proteins was saturable although not in the concentration range found in vivo. The drug was bound almost entirely to the alpha 1-acid glycoprotein fraction, to one class of binding sites with a moderate affinity constant (5.5 X 10(-4) M-1). Metabolism of carocainide, a secondary elimination process, occurred by oxidative cleavage of the benzofuran ring and by N-oxidation of the pyrrolidine ring.

A single VH-gene associated with a variety of D- and J-segments encodes for a large family of ABPC48-related antibodies induced by antiidiotypic immunization

Two series of monoclonal antibodies have been obtained from BALB/c mice immunized against two antiABPC48 antiidiotypic antibodies. They are divided into two serologically different classes. Class I antibodies bind only the immunizing antibody; class II antibodies display a broad binding capacity to various antiidiotypic antibodies, and some bind levan, as does ABPC48. Northern blot analyses and partial mRNA sequencing show that all class II antibodies express the VH-gene coding for ABPC48 and UPC10 antilevan antibodies associated with a variety of D- and J-segments. The third hypervariable region of the sequenced antibody with antilevan activity is structurally related to that of ABPC48 and UPC10 antibodies but has a different genetic origin. This study indicates that the identification of idiotype-related antibodies arising from antiidiotypic immunization may be misleading, if based on their antigen-binding properties; and it stresses the importance of structural approaches for the analysis of regulatory mechanisms ruling immune responses.

V kappa gene family in (Glu60 Ala30 Tyr10)n (GAT)-specific antibodies that express CGAT (or pGAT) public idiotypic specificities. Protein and mRNA sequencing of eight monoclonal V kappa chains

A large proportion of (Glu60 Ala30 Tyr10)n (GAT)-specific antibodies expresses public idiotypic specificities, termed CGAT (or pGAT), that require the presence of both the heavy and the light chains in order to be expressed. We report in this paper the complete sequence of eight V kappa regions pertaining to eight anti-GAT monoclonal antibodies derived from three strains of mice: BALB/c, DBA/2, and C57BL/6. The methodology used a combination of NH2-terminal amino acid and mRNA nucleotide sequencing. All eight sequences analyzed, although highly homologous and all pertaining to the same V kappa 1 subgroup, allowed definition of three germline genes that are likely to be present in all three strains of mice and also in NZB. It seems likely, however, that any given strain may not necessarily use all three genes for making anti-GAT antibodies. The search for structural correlates of idiotypes could not be framed in a simple picture, but our data suggest that similar idiotopes may result from different interacting primary structures, leading to structural homologies that should be visualized at three-dimensional level.

[Study of the spermatic bacterial flora in infertile males (author's transl)]

Two groups of infertile males (65 and 132 patients) have been investigated in two different laboratories, with two different methods to obtain semen. The bacteriological results are quite similar in the two groups. The microorganisms which have been isolated are : beta-hemolytic Streptococcus, Proteus, Epidermidis staphylococcus, Micrococcus, Corynebacter, Viridans streptococcus, Klebsiella, Pseudomonas, Enterobacter, Bacillus, Neisseria, Escherichia coli, anaerobic Staphylococcus, anaerobic Streptococcus, anaerobic Corynebacter type IV. Fungus, Achromobacter, 20 p. cent of the patients are chronically infected without any clinical signs. This infection is probably of prostatic origin with an important number of bacteria in the semen (more than 3 000/ml). No relation has been shown between the bacteriological data and the physical and cytological characteristics of the sperm, except the pH : semens with a low pH are generally azoospermic and highly contaminated.

[Study of the spermatic bacterial flora in infertile males (author's transl)]

Two groups of infertile males (65 and 132 patients) have been investigated in two different laboratories, with two different methods to obtain semen. The bacteriological results are quite similar in the two groups. The microorganisms which have been isolated are : beta-hemolytic Streptococcus, Proteus, Epidermidis staphylococcus, Micrococcus, Corynebacter, Viridans streptococcus, Klebsiella, Pseudomonas, Enterobacter, Bacillus, Neisseria, Escherichia coli, anaerobic Staphylococcus, anaerobic Streptococcus, anaerobic Corynebacter type IV, Fungus, Achromobacter. 20 p. cent of the patients are chronically infected without any clinical signs. This infection is probably of prostatic origin with an important number of bacteria in the semen (more than 3,000/ml). No relation has been shown between the bacteriological data and the physical and cytological characteristics of the sperm, except the pH : semens with a low pH are generally azoospermic and highly contaminated.

Partial structure of a rat IgD molecule with a deletion in the heavy chain

The isolation, purification and characterization of the rat IR-731 monoclonal immunoglobulin is reported. The molecule is IgD-like, as appreciated from immunochemical and biochemical characteristics. H and L chains, Fab and Fc tryptic fragments have been isolated, analyzed, and partial sequence data have been obtained, including most cysteyl-containing peptides. The heavy chain contains a deletion which encompasses most of the CH2 domain and the beginning of the CH2 domain, and observation which does not reflect the intron-exon organization depicted for some murine heavy chains at the gene level. Basic structural features of the hinge region of the IgD molecule (extreme susceptibility to proteolytic enzymes, presence of basic amino acids near its COOH-terminus) have been found for the IR-731 molecule. In addition, partial sequence of the light chains points to the existence of K subgroups in the rat. Very limited amino acid changes have been identified in the K constant region, suggesting a possible--but limited--polymorphism which might be isotypic and/or allotypic in nature.

[Pneumococcal capsular types of clinical specimens. Lyon: 1972-1977 and 1978 (author's transl)]

878 strains of Streptococcus pneumoniae were tested during two periods : 667 strains from 1972 to 1977 and 211 strains during 1978. Strains were isolated from spinal fluids, blood, peritoneal fluids, urines, exudate from respiratory tract except sputum. In polymicrobial specimens, only the predominant species were serotyped. From 1972 to 1977, 53,3% of strains are typed and 6 serotypes and pools are prevalent among 68,5% of typed strains, the most frequent are : 6 - D - 18 - 19. During the second period (1978) 82,5% of strains are typed, 9 serotypes are prevalent among 68,5% of typed strains, the most frequent are : 6 - 19 - 23 - 3. During 1978, 27,6% of strains are isolated from child wards, others from adults wards. A comparison of the relative frequencies of the serotypes in the two wards shows that the following 10 serotypes are the most frequent: 6 - 19 - 23 - 3 - 18 - 1 - 8 - 9 - 14 - 4.

The surgical treatment of fractures of the upper end of the humerus by blind pinning (author's transl)

During a period of five years, the authors have treated 250 fractures of the upper end of the humerus. Fifty-one were treated by blind pinning. Six to eight Kirschner wires are passed up to the head of the humerus under X-ray control through a hole made on the posterior aspect of the lower end of the humerus just above the olecranon fossa. The functional results were satisfactory in 70% of cases. The indications for pinning were for severely displaced fractures, comminuted fractures, either impacted or not, or slipping of the upper humeral epiphysis. The results were less satisfactory in cases with an elevated greater tuberosity. The technique cannot be applied to fracture-dislocations.

Structural and functional mapping of immunoglobulin V-regions

V-regions of immunoglobulins chains contain 3 types of positions, which are equally represented: invariant and sub-group characteristic, which account for the "framework" and hypervariable positions, responsible for antigen recognition. The 3 types of positions are grouped and fall within a very few discrete stretches. Sub-group characteristic segments containing one of the 2 cysteyl residues of the V-regions may be isolated by high voltage paper electrophoresis and provide a basis to type for sub-groups in the VK and in the VH human systems. This allowed to characterize a large set of human myeloma proteins that were used in a series of competitive hybridizations which indicated that sub-groups had no influence on preferential reassociations, which occurred in 80% of the cases. This preference seems to rely mostly on individual structural differences, which may be linked to heterogeneity at the framework level. Distinction between framework heterogeneity and hypervariable regions heterogeneity may be approached by raising antibodies against a mouse myeloma protein, MOPC 173, of known sequence, by means of syngeneic and allogeneic immunizations, using Balb/c and A/J mice. Junction of distinct portions of immunoglobulin chains such as the V and the C regions raises the possibility that some recognition signals may operate at the DNA level. Since rotational symmetry regions in the DNA are known to act as such signals, it is discussed whether such regions can be expected from the amino acid sequence data, especially in the vicinity of the "switch" peptide.