Piperacillin/tazobactam (Tazocin™) seems to be no longer responsible for false-positive results of the galactomannan assay.

OBJECTIVES: Galactomannan (GM) testing is extremely useful for diagnosing invasive aspergillosis in high-risk patients, but false-positive results have been reported in patients treated with piperacillin/tazobactam. The aims of this study are to test if the recent piperacillin/tazobactam (Tazocin™; Pfizer) preparation still contains GM, and if serum GM positivity in haematopoietic stem cell transplant (HSCT) recipients receiving piperacillin/tazobactam can be attributed to this treatment. PATIENTS AND METHODS: Serum samples obtained from 1 October 2009 to 31 October 2010 from HSCT recipients for GM testing were analysed. The difference in the rate of positive results (defined as GM ≥ 0.5) in patients receiving and not receiving piperacillin/tazobactam was evaluated. Piperacillin/tazobactam vials from randomly selected batches were tested. RESULTS: Of 1606 samples drawn in the absence of piperacillin/tazobactam therapy, 25 (1.6%) tested positive for GM versus 10 of 394 samples (2.5%) drawn while on piperacillin/tazobactam (P = 0.18). The median GM result of samples drawn on piperacillin/tazobactam was slightly higher than that of samples drawn in the absence of piperacillin/tazobactam (0.141 versus 0.122; P < 0.001). All 90 piperacillin/tazobactam vials from 30 randomly selected batches tested negative for GM, with a median GM value of 0.057 (range: 0.011-0.320). CONCLUSIONS: Although some residual GM might still be present in piperacillin/tazobactam, currently available brand piperacillin/tazobactam preparations seem no longer responsible for false-positive GM results.

Consequences of stable transduction and antigen-inducible expression of the human interleukin-7 gene on tetanus-toxoid-specific T cells.

Interleukin-7 (IL-7) has previously been shown to increase antigen-specific immune responses; the effect of IL-7 on human antigen-specific T cell lines has not directly been addressed. A tetanus-toxoid (TT)-specific T cell line exhibited increased proliferation in the presence of exogenous IL-7, suggesting that IL-7 may be useful in the potentiation of immune responses to defined microbial antigens. Murine retroviral vectors encoding the human IL-7 gene and the neomycin phosphotransferase gene (neoR) were packaged into murine retroviral particles, and supernatants containing these retroviral vectors were used to infect a CD4+ lymphoblastoid cell line. Stable integration of the retroviral vector and constitutive expression of the IL-7 gene were observed. Successful IL-7 gene transduction into TT-specific T cells was also accomplished. Detection of neoR DNA sequences and expression of IL-7-specific mRNA increased with selection in geneticin. Production of IL-7 in these cells was induced by exposure to TT. Production of IL-4, IL-6, and interferon-gamma (IFN-gamma) was detected after antigenic stimulation; there was, however, no effect of IL-7 on the pattern or kinetics of cytokine production by these cells. Human IL-7 transduced cells showed greater proliferation to TT than control T cells, particularly at subthreshold TT concentrations. These dta imply that genetic modification of antigen-specific T cells may be a plausible strategy for the study and manipulation of the immune responses to microbial pathogens.

Assessment of motor neuron excitability in parkinsonian rigidity by the F wave.

F-wave responses from abductor pollicis brevis muscle occurred more frequently, with a larger amplitude and longer duration in rigid parkinsonian patients than in age-matched normal controls. F-wave potentiation during voluntary contraction was impaired in parkinsonian patients. These findings suggest that spinal motor neuron excitability is enhanced in rigidity. F-wave amplitude was significantly correlated to the clinical evaluation of motor disability, so that the F wave may be regarded as a useful approach to quantitative evaluation of rigidity.

[Motor rehabilitation in spontaneous cerebral hematomas]. / Rieducazione motoria degli ematomi intracerebrali spontanei.

Author discuss problems of rehabilitation in patients affected by intracerebral hemorrhage. In the first, acute, phase attention has to be pointed on the prevention of osteoarticular lesions, pulmonary dysfunctions and sphincteric disturbances. In a second phase the most important topic is represented by a complete functional recovery. It is of great importance an intensive treatment of aphasia also in patients presenting a complete deficit.

[Granulomatous hepatitis. Apropos of a case with difficult etiological diagnosis]. / Le epatiti granulomatose. A proposito di un caso di difficile inquadramento eziologico.

Hepatic granulomatosis is an anatomo-pathologic feature, rising from the aspecific answer of the liver to various antigenic, toxic and infectious noxae. One of the most frequent symptoms of this disease is a some weeks lasting fever. The most frequent etiology is proved to be infectious, particularly tuberculosis, and sarcoidosis. In this paper an analysis of the various diseases which can produce hepatic granulomas is presented, as well as the clinical case of patient with fever and hepatic disease for whom it has been possible to get to an etioilogic diagnosis of tuberculosis only through an hepatic biopsy and culture of liver tissue.

Therapeutical aspects and outcome of HIV/HCV coinfected patients treated with pegylated interferon plus ribavirin in an Italian cohort.

BACKGROUND: One-third of HIV-infected individuals suffer from chronic hepatitis C virus infection (HCV) in Europe. Recommendations from HCV-HIV International Panel advise current treatment with pegylated interferon plus ribavirin. We assessed the impact of interferon and ribavirin combination in 43 patients between 2002 and 2006. PATIENTS AND METHODS: All coinfected patients treated for HCV during the 5-year period were included in retrospective data collection. CD4+ T-lymphocyte count, HAART discontinuation, reasons for treatment interruption and factors correlated to sustained virological response (SVR) were monitored. RESULTS: The mean age was 41 +/- 6.7 years; the risk factor for coinfection was intravenous drug abuse in 32/43 (74%). The baseline CD4+ T-lymphocytes cell count was > 500 in 51% (22/43). Genotype 3a represented 51% (22/43); 37% were on HAART at baseline (16/43) and half of patients showed high HCV RNA levels (> 800,000 IU/ml). High rates of treatment discontinuation were observed (27/43, 63%), caused by voluntary interruptions in 52% (14/27) and virological failure in 26% (7/27). The overall population had an SVR of 30%; genotypes 3a and 1 had SVR of 38% and 24%, respectively. The SVR was significantly lower in three groups: high HCV RNA viral load (chi2 = 6, p < 0.0025), CD4+ T-lymphocyte historical nadir <350 cells/mm3 (chi2 = 3.26, p < 0.01) and genotype 1 with high viral load (chi2 = 4.8, p < 0.005). CONCLUSIONS: Although factors such as HCV viral load rates and genotype 1 have been confirmed to threaten the response to therapy, we observed a significant response rate when patients had a history of CD4+ T-lymphocyte nadir >350 per mm3. The high dropout rates due to voluntary discontinuations complicated the patients' case management.

Soft-tissue infection with Absidia corymbifera and kidney complications in an AIDS patient.

We describe a case of primary cutaneous Absidia corymbifera infection in an AIDS patient with renal complications. The Sensititre YeastOne panel was adopted to determine antifungal susceptibility and liposomial amphotericin B was used which initially produced a significant clinical response.

Electroneurographic correlates of the monosynaptic reflex: experimental studies and normative data.

The neurographic concomitants of the monosynaptic reflex, evoked either by electrical stimulation of the tibial nerve at the popliteal fossa or by percussion of the Achilles tendon, have been recorded from the sciatic nerve in the lower and middle thigh. Neurographic recordings were characterised by two travelling waves (P1 and P2), respectively increasing and decreasing in latency in the proximal direction, that showed the same chronological trend of the propagated action potentials concurrently recorded in the dorsal and ventral spinal roots at the lumbar level. At variance with P2, the speed of propagation of the P1 volley was stimulus-related, being faster on mechanical than on electrical stimulation, probably because in the latter case the latency of the fastest afferents is overestimated. The P2 volley is subserved by alpha-efferent fibres in either case as suggested, inter alia, by the strict parallelism between the P2 volley and the monosynaptic reflex under appropriate experimental conditions. Simultaneous recordings of spinal root and sciatic nerve action potentials allowed the direct assessment of afferent and efferent conduction velocities, both in the proximal (that is from the middle thigh to the spinal recording site and vice-versa) and in the distal (that is from the lower to the middle thigh recording site and vice versa) segments of the reflex arc. As expected, the speed of propagation of impulses was significantly higher in the proximal than in the distal segments, as well as in the afferent than in efferent limb of the monosynaptic pathway. The P1-P2 time interval was longer on mechanical than on electrical stimulation, probably due to the increased spinal delay of the T versus the H reflex. The present study provides a reliable method for the direct assessment of alpha-efferent as well as of Ia afferent group fibres conduction velocity, provided that in the latter case mechanical stimuli be used.

[Recurrent Salmonella dublin infections]. / Infections récidivantes par Salmonella dublin.

A recurrent septicemia in a 8-year old child is reported. Blood and lymphnode tissue cultures permitte the isolation of Salmonella dublin. Despite the in vitro susceptibility of the isolated bacteria and the prolonged antimicrobial therapy, sepsis had a protracted course with relapses.

A comparative electrophysiological and histological study of sensory conduction velocity and Meissner corpuscles of the median nerve in pneumatic tool workers.

The sensory conduction velocity of the median nerve has been determined according to the technique described by Buchthal and Rosenfalck in 32 pneumatic tool workers and in 32 normal controls of the same age group. In each worker and in 8 normals of the same age group the Meissner corpuscles of the skin of the thumb of the side investigated were studied according to the technique described by Ridley and Dickens et al. The only relevant electrophysiological finding was represented by a decreased amplitude of the evoked response of the median nerve at the wrist, probably pointing to some degree of distal axonal degeneration. As to the histological findings, no significant variations from normal were found in the Meissner corpuscles of the workers. A trend towards a quantitative reduction of the corpuscles in those subjects who showed a decreased amplitude of the evoked response did not reach the level of significance.

Investigations on the nervous mechanisms underlying the somatosensory cervical response in man.

The main features (amplitude, latency and shape) of the cervical activity evoked by stimulation of the median nerve, recorded throughout the cervical spine, have been concurrently investigated by monopolar, bipolar longitudinal and bipolar transverse recordings. In some subjects the derivation C7-Sn (suprasternal notch) has been employed as well. A comparative evaluation of the refractory period of each component of the cervical responses under investigation has been performed to differentiate presynaptic from postsynaptic events. Additional information has been obtained by cervical activity recorded by longitudinal and transverse bipolar derivations upon stimulation of the lower limb. It was thus demonstrated that both presynaptic and postsynaptic events were responsible for the cervical sensory evoked potential, as appearing when recorded against a cranial reference (that is the upper midfrontal region). The structures involved were the brachial plexus (N9), the cervical roots (P10 and a minor part of N11a), the dorsal columns both at caudal (N11a) and rostral (N11b) cervical levels, and the dorsal column nuclei (N13). However a contribution of the spinal segmental activity to the postsynaptic portion of the cervical response, more specifically to N13, should be considered as well, though direct evidence is still inadequate.

Conducted and segmental components of the somatosensory cervical response.

Cervical responses evoked by stimulation of the median nerve have been concurrently recorded from C7--Fz and C7--Sn (suprasternal notch). The existence of two different waveforms (RI and RII) has been confirmed. RI (from C7--Fz) consists of four negative peaks (N9, N11, N13, N14) followed by a large positive deflection (P16). RII (from C7--Sn) is characterised by an early positive--negative spike (P1--N1a) followed by a slow negative--positive wave (N1b--P2). The study of the most relevant parameters (polarity, latency and refractory period) of each component of RI and RII did not indicate whether the generators underlying RI differ from those responsible for RII. However, stimulation of the lower limb, which does not involve segmental events at cervical level, showed a clearcut difference: no response was recorded from C7--Sn, while evoked activity equivalent to RI was obtained from C7--Fz. Therefore it is suggested that RII is entirely generated by segmentally evoked potentials while RI is mainly due to conducted potentials.

Proprioceptive modulation of somatosensory evoked potentials during active or passive finger movements in man.

The effects of active and passive finger movements on somatosensory potentials evoked by stimulation of the median nerve at the wrist or of finger I were investigated in 15 healthy volunteers. As compared to the resting condition, both active and passive movements of the stimulated hand fingers induced a marked reduction in the amplitude of the primary cerebral response (N20-P25 complex) as well as of the N17 SEP component, which is supposed to reflect the activity of the thalamo-cortical radiation. The following cerebral SEP components, within 100 ms after the stimulus, were also depressed during motor activity. Neither N11 nor N13 components of the cervical response, reflecting the activation of dorsal columns and dorsal column nuclei respectively, were modified. The SEP changes induced by active or passive movements were absent after ischaemic block of large group I afferent fibers from the hand, thus suggesting the relevance of the feedback generated by such peripheral afferents during movement. The results indicate that the activation of peripheral receptors (probably muscle spindle endings) during both active and passive finger movement would induce a gating effect at both cortical and subcortical (thalamic) level, which might modulate selectively the different sensory inputs to the cortex.

Tonic vibration reflex in Holmes-Adie syndrome: an electrophysiological study.

The pathophysiological mechanisms underlying benign areflexia were studied in six patients with Holmes-Adie syndrome. No impairment of sensory conduction velocity of sural nerve was found. A normal tonic vibration reflex was obtained in all patients. H reflex was absent in five patients, but responses like F waves were recorded in three subjects. These findings suggest that muscle spindles are not affected and that spinal motoneurone excitability is normal.

Spinal components of the cerebral somatosensory evoked response in normal man: the "S wave".

Responses evoked over the scalp and the neck by median nerve (or finger I) stimulation were concurrently recorded in 10 subjects. It was found that the first component of the cortical SEP consists of a small amplitude polyphasic wave (S wave) which could be recorded bilaterally upon unilateral stimulation. The polarity of the S wave varied according to the reference electrode position, at variance with the P15 component which remained constantly positive. It is therefore correct to assume that different generators are responsible for these two potentials. The synchrony between the S wave and the cervical response, which is largely spinal in origin, as well as some pertinent experimental data, suggest that the S wave is a far field reflection of activity generated mainly in the cervical dorsal columns. These findings might be relevant to the diagnosis of neurological disorders.

New subcortical components of the cerebral somatosensory evoked potential in man.

Two new components of the human SEP upon stimulation of the contralateral median nerve at the wrist have been identified. Such components have been called N16 and N17, according to their polarity and latency. N16 and N17, as well as the N14-P15 complex, are generated by separate subcortical dipoles. Particularly, they are supposed to be far-field reflections of the activity of the dorsal columns nuclei or the medial lemniscus (N14-P15), the thalamus (N16) and the thalamo-cortical radiation (N17). Moreover, it has been established that N14 is the very first intracranial component of the human SEP, the main peak of S wave and the preceding ones being extracranial in origin. A new classification of SEP intracranial components including early (N14 through N17), intermediate (N20 through P30) and late events is proposed.