4-Substituted trinems as broad spectrum beta-lactamase inhibitors: structure-based design, synthesis, and biological activity.

A wide variety of pathogens have acquired antimicrobial resistance as an inevitable evolutionary response to the extensive use of antibacterial agents. In particular, one of the most widely used antibiotic structural classes is the beta-lactams, in which the most common and the most efficient mechanism of bacterial resistance is the synthesis of beta-lactamases. Class C beta-lactamase enzymes are primarily cephalosporinases, mostly chromosomally encoded, and are inducible by exposure to some beta-lactam agents and resistant to inhibition by marketed beta-lactamase inhibitors.

EFNS guideline on mild traumatic brain injury: report of an EFNS task force.

In 1999, a Task Force on Mild Traumatic Brain Injury (MTBI) was set up under the auspices of the European Federation of Neurological Societies. Its aim was to propose an acceptable uniform nomenclature for MTBI and definition of MTBI, and to develop a set of rules to guide initial management with respect to ancillary investigations, hospital admission, observation and follow-up.

Design, synthesis and bioactivity evaluation of tribactam beta lactamase inhibitors.

Known carbapenem compounds with inhibitory effect towards beta-lactamase enzymes are formed from bicyclical beta lactam structural scaffolds. On the basis of results from theoretical computational methods and molecular modelling we have designed and developed a synthetic route towards novel, biologically active tricyclic derivatives of carbapenems.

Can somatosensory system generate frequency following response?

The aim of this study was to establish whether functional characteristics of the somatosensory system structures in man comply with the frequency following response (FFR) generators. Somatosensory cerebral evoked potentials (SsCEP) were recorded by skin electrodes, and spinal somatosensory evoked potentials (SpEP) both by epidural and skin electrodes. In SpEP and SsCEP to trains of electrical or mechanical stimuli, a decrease of the amplitude to subsequent stimuli was found.

A noninvasive method of neurography in meralgia paraesthetica.

The lateral femoral cutaneous nerve (LFCN) becomes superficial 10 cm distal to the anterior superior iliac spine, where it can be located and stimulated by superficial electrodes. This is not the case in the inguinal region. In the present study the LFCN compound nerve action potential (NAP) was recorded with a pair of 8-cm-long strip electrodes placed on the anterolateral aspect of the thigh 25 cm distal to the stimulating electrodes.

Measurement of light touch perception threshold by contingent negative variation.

An objective method developed to measure the threshold of light touch perception using contingent negative variation (CNV) is described. The light touch stimulus was a slight indentation of the skin produced through a displacement controlled stimulating probe (tip diameter of 2 mm). It was applied as the conditioning (S1) stimulus of the classical CNV paradigm of S1, S2, and R.

Epidurally recorded cervical spinal activity evoked by electrical and mechanical stimulation in pain patients.

Spinal SEPs to electrical and mechanical stimulation of the upper limb of the non-painful side in 7 pain patients were recorded from the cervical epidural space. In response to electrical stimulation of the median nerve, the longitudinal distribution of the spinal postsynaptic negativity (N13) along the cord had a distinct level of maximal amplitude at the C5 vertebral body. When recorded at increasing distances cranial or caudal to this level, the latency of N13 was successively prolonged, in agreement with a spread-out near-field generator in the dorsal horn.

Epidurally recorded cervical somatosensory evoked potential in humans.

Three slow wave components, P10, N13 and P18, can be seen in the cervical somatosensory evoked potential (CSEP) in response to median nerve stimulation recorded by an electrode in the epidural space at the dorsal aspect of the cervical spinal cord referenced to an electrode at the suprasternal notch. In the region of high CSEP amplitude, which extends over several cervical segments, the peak-to-peak amplitude is more than 10 microV, permitting observation of the CSEP slow waves in single, unaveraged records. The CSEP to finger nerve stimulation had a similar wave form and the same latencies (referred to the Erb's potential) as the CSEP to median nerve stimulation.

Maturation of cortical potentials evoked by tibial-nerve stimulation in newborns, infants and children aged four and eight years.

This study traced changes in cortical activity (SsCEP) evoked by electrical stimulation of leg nerves during the period of fast morphological and functional development of the nervous system from birth to eight years of age. The study revealed complex waveform changes in the SsCEP during this period. At birth low-amplitude potentials with well-defined, simple, three-phasic waveform (P1, N2P2N3, P3) were present in only eight of 26 newborns: no SsCEP could be detected in 13 cases.

Auditory potentials in profoundly deaf subjects.

In 12 healthy volunteers, and 5 prelingually and 5 postlingually profoundly deaf subjects, a 500 Hz filtered click stimulus was applied to the mastoid via the bone conductor. In all the healthy volunteers, middle latency response (MLR) was recorded. Among all profoundly deaf subjects, MLR was recorded only in 2 with prelingually deafness; these two subjects were also the only ones with normal vestibular function.

Frequency following response evoked by vibratory stimuli in profoundly deaf subjects.

A vibratory stimulus at a frequency of about 100 Hz was transmitted through a bone conductor on the mastoid in 26 profoundly deaf subjects. In all of them, the function of the vestibular apparatus was tested by means of the Fitzgerald-Hallpike caloric test. In some of the deaf subjects, evoked potentials were recorded, which following the frequency of the stimulus and which according to amplitude and latency characteristics, corresponded to the frequency following response (FFR).

Contingent negative variation audiometry in children.

The aim of the present work was to establish whether contingent negative variation audiometry (CNV-A) is applicable to children. In a group of 23 children aged 5-7 years, only 10 generated clearly recognizable CNV when tested with the method successfully used in adults. When the procedure was modified by prolonging the S1-S2 interval and by introducing attractive slides to serve as the S2 stimulus and by adopting a slower repetition rate, 9 children randomly selected from the former group generated high-amplitude CNV (10.

Frequency-following response evoked by acoustic stimuli in normal and profoundly deaf subjects.

A low-frequency acoustic stimulus was applied to the right mastoid, the right acromion and the distal phalanx of the right index finger in 10 healthy and 10 profoundly deaf subjects. The stimulus, which had a frequency of 80-120 Hz, was delivered by means of a special vibrating system, constructed for this purpose. The frequency-following response (FFR) was recorded.

Somatosensory perception and cortical evoked potentials in established paraplegia.

In 66 patients who suffered severe spinal cord injury 7 months to 28 years previously, somatosensory cortical evoked potentials were recorded to electrical stimulation of the leg nerves and compared to clinical assessment of light touch, pain, position sense and two-point discrimination. The patients were separated into 4 categories according to the degree of disintegration of the somatosensory evoked potential waveform. A clear correlation was found between the impairment of somatosensory perception and the deterioration of the somatosensory evoked potential in each group.

Distribution of scalp somatosensory potentials evoked by stimulation of the tibial nerve in man.

The scalp distribution of the response to stimulation of the tibial nerve at the medial malleolus was systematically analysed. The somatosensory evoked potential (SEP) was recorded with electrodes placed in a transversal line over the ipsilateral and contralateral postcentral gyri and in a sagittal line over the longitudinal brain fissure. The SEPs recorded over the ipsilateral hemisphere and along the sagittal line were similar to the F response (the response over the foot primary somatosensory region).

Dependence of visual evoked potentials on change of stimulated retinal area associated with different pattern displacements.

An attempt was made to distinguish between the effects of the moving edges and the change in the area of stimulated retina on pattern shift visual potentials, elicited by checkerboard pattern displacements varying through 0.25, 0.50, 0.

A study of posterior column function in familial spastic paraplegia.

A family is described in which affected members have clinical features consistent with the late onset form of Strümpell's Familial Spastic Paraplegia which is of dominant inheritance. Abnormalities in cortical somatosensory to peroneal nerve stimulation were found in all affected members of the family and in several who were clinically unaffected. In some cases responses were better defined at slow rates of stimulation.

The early negative potential evoked by stimulation of the tibial nerve in man.

The scalp response to stimulation of the tibial nerve at the level of the medial malleolus was systematically analysed. It was recorded 2 cm posterior to the vertex and at the sites corresponding to cortical representation of the hand. The existence of an early negative wave with a peak latency of 37.

Improved contingent negative variation audiometry.

In earlier reports we described contingent negative variation audiometry (CNV-A) and explored the accuracy of the method used in clinical conditions. Amplitude was found to be the factor which determines the accuracy of CNV-A. With this study we aimed to increase the amplitude of the CNV so as to improve the accuracy of CNV-A.

Improvement of gait following functional electrical stimulation. I. Investigations on changes in voluntary strength and proprioceptive reflexes.

Patients with central spastic paresis and equipped with peroneal stimulators sometimes experience an improvement in their gait, even when the stimulator has been switched off. The object of the present investigation was to reach a better understanding of the mechanisms operating in such cases. 7 patients were investigated on repeated occasions.