Clinical cross-reactivity between amoxicillin and cephadroxil in patients allergic to amoxicillin and with good tolerance of penicillin

In recent years, patients allergic to amoxicillin (AX) but with good tolerance of penicillin G (PG) have been described. It has been suggested that the epitope implicated in this type of sensitization might be located on the side-chain of the AX molecule. Thus, cross-reactivity between AX and cephadroxil (CEPH), a cephalosporin which shares an identical side-chain with AX, is suspected. This study aimed to demonstrate clinical cross-reactivity between AX and CEPH in patients allergic to AX and showing good tolerance of PG. In 76 of 576 subjects with suspected allergic reaction to PG and/or AX, the diagnosis of allergy was confirmed. All of these had specific IgE to PG, penicillin V, or AX, and/or positive skin tests to PPL (penicilloyl-polylysine), or MDM (minor determinant mixture), or PG, or AX, and/or positive challenge tests with PG and/or AX. Sixteen subjects (21%) allergic to AX (11 with positive skin test and five with positive challenge test to AX) and good tolerance of PG (all with negative parenteral challenge test) were selected. These 16 patients were subsequently challenged with CEPH (up to 500 mg). Fourteen patients tolerated CEPH, and two (12%) had an immediate allergic reaction. Our study indicates that allergy to the side-chain of aminopenicillins seems to have little clinical relevance in patients with allergic reactions to aminopenicillins but with good tolerance of PG, as 88% of patients with this clinical characteristic tolerate a cephalosporin which shares an identical side-chain. It seems that IgE from most of these patients recognizes an epitope different from the side-chain and the beta-lactam ring.

Clinical experience with transcranial cerebral oximetry

Transcranial cerebral oximetry based on the principle of near-infrared spectroscopy has been successfully used in a variety of neurosurgical conditions, primarily those associated with disturbed cerebral circulation. The non-invasive technique of cerebral oximetry provides valuable information about brain oxygenation in patients with cerebral ischemia (due to occlusion or stenosis of the internal carotid artery). It is also used in intraoperative monitoring of carotid endarterectomy and surgical procedures performed under deep hypothermia and circulatory arrest, during neuroendovascular procedures, and in critical care settings (in patients with arterial vasospasm and during the terminal period). This article describes our preliminary clinical experience with the use of this new technique and summarizes the current literature on clinical and experimental use of transcranial cerebral oximetry.

Periovulatory LHRH, LH and FSH secretion in cyclic rats treated with RU486: effects of exogenous LHRH and LHRH antagonist on LH and FSH secretion at early oestrus

The antiprogesterone RU486 injected on the morning of pro-oestrus blunts the preovulatory secretion of LH and FSH and abolishes the secondary secretion of FSH during oestrus without affecting ovulation in the rat. To ascertain whether the secretion of LHRH is involved in these effects, we studied the effects of RU486 (4 mg/0.2 ml oil), given s.c. at 0800 h on pro-oestrus, on LHRH secretion into the pituitary stalk blood vessels and on peripheral plasma concentrations of LH and FSH at 1800 h on pro-oestrus and 0200 h on oestrus. Furthermore, we determined the effects of an s.c. injection of 1 mg of an LHRH antagonist (LHRH-A; ORG30276) at 2000 h on pro-oestrus and those of an i.p. injection of 100 ng LHRH (Peninsula 7201) at 0100 h on oestrus on serum concentrations of LH, FSH and oestradiol at 0200 h on oestrus in oil- and RU486-treated rats. RU486 decreased LHRH secretion at 1800 h on pro-oestrus while this was increased at 0200 h on oestrus. While the reduction of preovulatory LHRH secretion in RU486-treated rats coincided with a reduction in both LH and FSH surges during the evening of pro-oestrus, the increased LHRH secretion during the early hours of oestrus was only accompanied by an increased concentration of LH. An injection of LHRH stimulated, while that of LHRH-A inhibited serum concentrations of LH at 0200 h on oestrus in both oil- and RU486-treated rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Electro-optic high-resolution Fabry-Perot spectrometer

A single-crystal lithium niobate dtalon suitable for high-spectral-resolution studies has been operated successfully. This étalon with a 5-cm clear diameter and a gap equivalent to 2 cm in air has been found to have very linear response in wave number as a function of voltage. The combined advantages of adjustment-free operation, linearity in operation, and high luminosity in a small size (as a result of the μ(2) gain in the instrumental throughput caused by the large index of refraction of the lithium niobate substrate) make for a rugged instrument that is ideal for long-term unattended field operation.

Techniques for deriving Doppler temperatures from multiple-line Fabry-Perot profiles: an analysis

Two techniques for recovery of the Doppler temperature from Fabry-Perot spectrometer observations of multiple-line profiles are tested. A direct fit of a modeled profile to the data is found to produce more consistent results and is less sensitive to noise than the method of least-squares fitting to low-order Fourier-transform coefficients derived from the data. This result is unexpected since the Fouriertransform method permits the reduction of noise by truncating the series of coefficients used to determine the temperature.

A rare case of a multicentric peripheral ameloblastoma of the gingiva. A light and electron microscopic study

A rare case of a multicentric peripheral ameloblastoma of the gingiva in a 54-year-old male patient is described along with a light and electron microscopic study of the excised tumors. The peripheral ameloblastoma is considered to be the gingival counterpart of the more common intraosseous ameloblastoma. Although both tumors have similar histomorphologic characteristics, their clinical appearance and behavior are completely different. The peripheral ameloblastoma is slow growing and non-invasive, and recurrence is uncommon following excision. The more common central ameloblastoma, is locally invasive and can destroy large segments of the jaw. The histogenesis of the peripheral ameloblastoma and several other odontogenic tumors of the gingiva serves to illustrate the proliferative potential of the basal cell layer of gingival epithelium.

Aggressive periodontal destruction and herpes zoster in a suspected AIDS patient

An unusual case of spontaneous and rapidly destructive lesions involving the periodontal structures is described in a 54 year old, bi-sexual patients suspected of having AIDS. Concomitant with the periodontal breakdown, the patient developed a severe case of Herpes Zoster involving the area of the face innervated by the 5th cranial nerve. The dermal lesions involved the face, nose, eyes and scalp. Similar lesions were noted on the gingival and palatal mucosa on the same side of the jaw as the skin lesions. The differences between this type of periodontal destruction and more conventional forms of periodontitis are discussed.

Comparison of dipyridamole-echocardiography with dipyridamole-thallium scintigraphy for the diagnosis of myocardial ischemia

After an intravenous infusion of dipyridamole (0.56 mg/kg), we performed both echocardiography and thallium scintigraphy in 63 patients who were referred for known or suspected coronary artery disease. Of those patients, 25 returned for coronary arteriography within 1 month after the tests, thus forming the study group for this report. Sensitivity for detection of coronary artery disease, when analyzed region-by-region, was 80% for thallium scintigraphy and 57% for echocardiography, whereas specificity was 85% and 98%, respectively. When evaluating individual patients for the presence or absence of ischemia, we found a sensitivity of 95% for scintigraphy and 58% for echocardiography; corresponding specificities were 50% and 100%. By using arteriography as the gold standard for comparison, it appears that thallium scintigraphy has a significantly higher sensitivity but lower specificity for the detection of coronary artery disease than does echocardiography. Echocardiography may, however, be a useful adjunct to thallium scintigraphy in the evaluation of patients with coronary artery disease.

Radiosurgical treatment of low flow carotid-cavernous fistulae

The good results obtained by stereotactic radiosurgery in arteriovenous malformations has led the authors to expect similar results in low flow carotid-cavernous fistulae. In this paper, 20 cases who underwent radiosurgery with a conventional gamma source are presented. The total dose delivered was 36 to 40 Gy. 90% of the patients were cured after radiosurgery after a mean time of 7 months. Those presenting a mild improvement after a mean time of 2 months and those with a marked improvement after 4 months.

Castration reduces the nocturnal rise of pineal melatonin levels in the male rat by impairing its noradrenergic input

Abstract The effects of castration and testosterone treatment on pineal day-night rhythms were studied in male rats. Bilateral gonadectomy was performed at 21 days of age. Testosterone propionate was given subcutaneously to castrated animals in a dose of 10 mug/100 g body weight during two consecutive days before sacrifice. Animals were killed 40 days after gonadectomy at four different times of a 12:12 h light-dark cycle (1600, 2400, 0400 and 0800h). Tyrosine hydroxylase activity was measured in individual pineals by means of high-performance liquid chromatography determination of L-DOPA formed. Pineal levels of norepinephrine, dopamine, 5-hydroxytryptamine and 5-hydroxyindole acetic acid were determined by high-performance liquid chromatography with amperometric detection, while pineal melatonin content was measured by radioimmunoassay. Castration abolished the day-night rhythms of pineal tyrosine hydroxylase activity and norepinephrine content, both by elevating their daytime levels and by blocking their nocturnal rise. In addition, gonadectomy drastically modified pineal indoleamine metabolism by increasing daytime levels of both 5-hydroxytryptamine and 5-hydroxyindole acetic acid, and by reducing the nocturnal elevation of pineal melatonin content. Testosterone treatment was unable to prevent the effect of orchidectomy on pineal rhythms of tyrosine hydroxylase activity, 5-hydroxytryptamine or 5-hydroxyindole acetic acid content, however it partially restored the day-night pineal rhythms of both norepinephrine and melatonin content. These results are indicative of a possible participation of reproductive hormones in the control of pineal rhythmic activity in the male rat. Apparently, since gonadectomy abolished the nocturnal rise of both pineal tyrosine hydroxylase activity and norepinephrine content, the primary site of action of reproductive hormones could be at the level of the superior cervical ganglion.

Ovarian steroids block the isoproterenol-induced elevation of pineal melatonin production in the female rat

Changes in pineal indole metabolism during the estrous cycle, as well as in response to estrogen administration, were studied in female rats. Tyrosine hydroxylase (TH) activity, norepinephrine (NE) and indoleamine levels were determined by high-performance liquid chromatography (HPLC). Pineal melatonin was measured by radioimmunoassay (RIA). Both 5-hydroxytryptamine (5-HT) and melatonin levels, but not TH activity or NE content, were reduced during proestrus. Ovarian hormones blocked the isoproterenol-induced elevation of pineal melatonin, and reduced 5-HT levels in ovariectomized rats. These results suggest that an estrogen-induced inhibition of the pineal response to adrenergic stimulation, could be responsible for the reduction in pineal melatonin production occurring during the proestrus stage of the rat estrous cycle.

Recurrent left ventricular pseudoaneurysm: diagnosed by color-flow Doppler echocardiography

The effects of left ventricular pseudoaneurysm following transmural myocardial infarction can be devastating; therefore, prompt diagnosis and surgical resection are warranted. We report a rare case of recurrent left ventricular pseudoaneurysm in which color-flow Doppler echocardiography was useful in establishing the diagnosis.

Determination of pineal melatonin by high-performance liquid chromatography with electrochemical detection: application for rhythm studies and tissue explants

High-pressure liquid chromatography with electrochemical detection has been used for the determination of melatonin in rat pineal glands and tissue explants. Rat pineal melatonin content was measured at 2-hr intervals during a 24-hr period by direct injection of supernatants from centrifuged pineal homogenates into a reversed-phase C18 column. The lower limit of sensitivity was 32 pg per gland for a 2:1 signal-to-noise ratio, which allows melatonin measurements during daytime. Both absolute values and circadian rhythmicity obtained with the present method are in agreement with previously validated radioimmunoassays. In addition, isoproterenol-induced release of melatonin from individual rat pineal explants was measured after chloroform extraction of the incubation medium.

[Usefulness of repeated measurement of plasma levels of gentamycin]

We monitored plasma levels of gentamycin in 28 patients being treated for different infectious processes. The mean age was 53.7 years. Drug dose and administration was determined by the treating physician, without knowledge of plasma levels. Peak and through levels were measured by RIA after the third and 7th dose. No patient had adequate therapeutic levels throughout the treatment period and 6 were therapeutic failures. Patients with renal insufficiency frequently had toxic plasma levels. Monitoring gentamycin plasma levels is recommended for all patients receiving the drug, especially those with renal insufficiency or therapeutic failure.

The effect of presumptive polyadenylation signals on the expression of the CAT gene in transgenic tobacco

Promoter::gene fusions which differed only in the presumed polyadenylation signals attached to the 3' end of the gene, have been used to examine the effect of these signals on expression of the gene in protoplasts and in transgenic plants. The gene constructs were comprised of the 35S promoter, the chloramphenicol acetyl transferase (CAT) gene and DNA sequences carrying the presumed polyadenylation signals of the nopaline synthase (nos) gene or of transcript 7 (T-7) from the T-DNA ofAgrobacterium. Our results show that levels of gene expression were not significantly affected by the orientation or absence of these sequences. We therefore suggest that the practice of cloning presumptive polyadenylation sequences at the 3' end of a gene for expression in plants may be unnecessary.

Reproductive hormones control striatal tyrosine hydroxylase activity in the male rat

The effects of castration, hypophysectomy and testosterone treatment on striatal tyrosine hydroxylase (TOH) activity were examined in male rats. Enzyme activity was measured by means of high-performance liquid chromatography (HPLC) determination of L-3,4-dihydroxphenylalanine (DOPA) formed. Serum levels of both testosterone and luteinizing hormone (LH) were measured by radioimmunoassay (RIA). Castration, but not hypophysectomy, reduced TOH activity in the striatum. The administration of testosterone propionate (TP) to castrated animals in a dose of 10 micrograms/100 g b.wt. during the two days previous to sacrifice, completely prevented the castration-induced reduction of striatal TOH activity. In orchidectomized rats treated with different doses of testosterone propionate (TP) up to 20 micrograms/100 g b.wt., the levels of striatal TOH activity were apparently related to either the dose-related increase of serum testosterone or the decrease of serum LH. Higher doses of the androgen failed to further modify striatal TOH activity, in spite of the dose-related elevation of serum testosterone concentration. These results suggest that circulating levels of gonadal and/or pituitary hormones partially control dopaminergic synthesis in striatal terminals, which in turn may account for some behavioral effects of reproductive hormones.

Afocal coupled etalons: experimental confirmation of a high-resolution double-etalon modulator spectrometer

Experimental verification of the properties of a spectroscopic device consisting of two etalons coupled by an afocal system, and which behaves as a high-luminosity single-etalon single-aperture Fabry-Perot spectrometer, has been made. These preliminary results, limited by the available equipment, confirm the predicted theoretical properties of the double-etalon modulator device. As a corollary to this experimental verification, it has been found that successful operation of the device requires very close alignment of the optical axes of the etalons.

Differential effects of verapamil on various gastric lesions in rats

Verapamil (3, 10, 20 mg/kg-1) increases the necrotizing effects of oral 25% NaCl or 100% ethanol. Damage by 0.6 N HCl was not equally affected since 1 mg/kg-1 of verapamil decreased the ulcer index whereas the higher doses augmented it. Pharmacologically induced gastric lesions were also differently affected by verapamil, ulcers produced by histamine being greatly enhanced and those of reserpine inhibited. Neither indomethacin nor compound 48/80 ulcers were modified. These results suggest that verapamil modifies the susceptibility of the gastric mucosa to damage.

Afocal coupled etalons. DEM: a high-resolution doubleetalon modulator spectrometer

The properties of a spectroscopic device consisting of two etalons coupled by an afocal system, and which behaves as a high-luminosity single-etalon single-aperture Fabry-Perot spectrometer, have been investigated. Although the high-luminosity behavior is one of the many states in which a coupled dual-etalon system can exist, mainly the high-luminosity condition has been studied in detail here. This condition is reached when the orders of the etalons comprising the device are related by n(01) = n(02)eta(-2), where the coupling constant is defined as eta = micro(1)micro(-1)(2)f(1)f(-1)(2) micro(i) and f(i) are the indices of refraction and coupling lens focal length associated with the ith etalon. In high-luminosity conditions, one of the etalons serves as a multiple annuli mask for the other thus making it possible to use many of these annuli to achieve the desired high throughput. The limitation on the number of orders usable is given by the (small) nonlinearity in the matching of these orders, because of the different etalon gaps. The results of the study show that luminosity gains near 100 (when compared with a single-etalon single-aperture Fabry-Perot spectrometer) are possible at high resolving powers. This occurs when the coupling constant eta is not too far from unity. It is also shown that this device, or double-etalon modulator (DEM), is a compensated spectrometer since the gain increases with increasing resolving power. Other practical limitations, such as the beam walk-off from the edges of finite size etalons, are discussed.

Day-night rhythm of rat pineal tyrosine hydroxylase activity as determined by HPLC with amperometric detection

Tyrosine hydroxylase activity in the rat pineal gland was measured by means of HPLC determination of the amount of L-3,4-dihydroxyphenylalanine formed. Enzyme activity showed a clear day-night rhythm, paralleling that of plasma melatonin levels in the same animals, with values being high during the dark period apparently because of changes in Vmax. In animals maintained under constant illumination for 3 days, tyrosine hydroxylase activity and plasma melatonin level rhythms were completely abolished, a result indicating that both are under photoperiodic control.

Analytical description of a Fabry-Perot spectrometer. 8: Optimum operation with equidistant equal-noise sampling

The optimum parameters of operation for a Fabry-Perot spectrometer used in the equidistant equal-noise sampling method have been calculated. The results, expressed in terms of normalized halfwidths at half-height, are: etalon (a*) = 0.078 (0.095), linewidth (dg*) = 0.13 (0.19), and aperture (f*) = 0.10 (0.19) for temperature (wind) determinations. The etalon widths correspond to rather low reflectivities, namely, 0.62 and 0.56. The critical number of samples, required for unambiguous determinations of a measured profile, are found to be equal to 8 and 12. The usefulness of the equal-noise method in absorption measurements is discussed.

Radiosurgical treatment of epilepsy

Focal irradiation of epileptic foci has been performed in a group of 6 epileptic patients, of whom 2 presented with epilepsy and 4 with epileptic psychoses. The epileptic focus was localized by means of conventional scalp EEG, electrocorticography and stereoelectroencephalography. Radiosurgery was performed by coupling a stereoguide to a 60Co unit using a 10-mm diameter collimator. An estimated dose of 10 Gy was administered. Results are presented and the mechanism of action of radiation discussed.

Different roles of catecholaminergic and serotoninergic neurons of the medial forebrain bundle on male rat sexual behavior

The medial forebrain bundle (MFB) plays an important role in the central elaboration of male sexual behavior. However the role of its ascending monoaminergic systems is not well understood. By selective lesions of catecholaminergic and serotoninergic axons of the MFB, produced with 6-OHDA and 5-7-DHT respectively, its possible involvement in male sexual behavior was studied. The evaluation of the behavioral patterns was studied by means of a microcomputer which also permitted the quantification of sequences in the sexual behavior patterns. Lesions with 5-7 DHT increased the intromission-ejaculation sequences and the percentage of ejaculatory males, without modifying other behavioral tests. Lesions with 6-OHDA diminished the number of "active" sexual patterns and motor activity. In order to check the specificity of the chemical lesions, the in vitro uptake of labeled norepinephrine and serotonin was measured, 5-7 DHT lesioned rats show a reduction in the uptake of 5-HT-C14 in the MPOA while 6-OHDA group show a reduction of NA-H3 in the striatum.

Pineal indols and testosterone affect exploratory activity of male rats

The testosterone level has an inverse relation to activity in the open-field test. This is more important in red light than in white light. Pineal indols do not disturb this action. Some of these results are consistent with the assumption that androgens play a role on the exploratory activity of adult subjects.