[Characterization of de novo malignancies in liver transplantation]

INTRODUCTION

The incidence of de novo malignancies after liver transplantation varies from 3-15%, and is greater than that in the general population. Immunosuppression may play a significant role in the development of most of these tumors.

OBJECTIVE

To evaluate the incidence and clinical features of de novo tumors in liver transplant recipients in our center as well as to assess survival.

PATIENTS AND METHODS

We retrospectively analyzed 437 liver transplantations (380 patients) performed from April 1990 to July 2001. The incidence of de novo malignancies was 7.4% (n = 28). Four patients presented two different tumors during their lifetime. The etiology of the underlying disease was alcoholic cirrhosis (45.8%), hepatitis C virus cirrhosis (20.8%), hepatitis B virus cirrhosis (12.5%), autoimmune disease (8.4%) and other causes (12.5%). The most frequent neoplasms were cutaneous and epidermoid tumors (21.4% of the malignancies both groups). All the patients with epidermoid tumors and adenocarcinomas were active smokers. The mean age at diagnosis was 58 9 years and this was a factor that influenced tumoral type (adenocarcinomas in older patients and epidermoid tumors in younger patients; p = 0.04).

RESULTS

Sarcomas and adenocarcinomas appeared sooner after transplantation than epidermoid and cutaneous tumors (p = 0.04). Fifty percent of the malignancies developed in the second and third year after transplantation. The type of immunosuppression did not influence tumoral type, although most patients received cyclosporin A in combination with azathioprine and/or corticoids. The mean duration of follow-up after diagnosis of the tumor was 23.1 28 months (range, 1-81). Mortality was 58.4% with a median survival of 9 16 months. The actuarial probability of survival at 1, 3 and 5 years was 46.1, 27.7 and 27.7%, respectively.

CONCLUSIONS

De novo malignancies are frequent after liver transplantation and their clinical course differs from that in the general population. Because their clinical course is more aggressive, regular follow-up of these patients is essential for early diagnosis.

P53 overexpression predicts endometrial carcinoma recurrence better than HER-2/neu overexpression

OBJECTIVE

to investigate the prognostic value of p53 and HER-2/neu overexpression in endometrial cancer.

STUDY DESIGN

p53 and HER-2/neu immunostaining was performed in 114 paraffin-embedded specimens of endometrial cancer diagnosed and treated between 1990 and 1997. Nuclear p53 and membrane HER-2/neu immunostaining were used.

RESULTS

p53 and HER-2/neu overexpression was observed in 17 cases (14.9%) and in 19 cases (16.7%), respectively. In univariate analysis p53 (P<0.001) and HER-2/neu (P=0.018) overexpression had a positive correlation with a high risk of recurrence. In multivariate analysis, age (P<0.001), FIGO stage (P<0.001), differentiation (P=0.013), non-endometrioid subtypes (P<0.001) and p53 overexpression (P<0.001), but not HER-2/neu overexpression, were independent prognostic indicators of recurrence. Simultaneous p53 and HER-2/neu overexpression made worse the prognostic (P<0.001).

CONCLUSIONS

p53 overexpression was an independent predictor of recurrent disease in endometrial cancer. HER-2/neu overexpression had a more limited effect but enhance the effect of p53.

A comparison of epithelial membrane antigen overexpression in benign and malignant endometrium

OBJECTIVE

The aim of this study was to analyze the value of epithelial membrane antigen (EMA) overexpression in benign and malignant endometrium and its prognostic significance.

METHODS

EMA immunostaining was performed in 178 paraffin-embedded specimens including 105 endometrial cancers, 40 endometrial hyperplasias, and 33 benign endometriums. EMA immunostaining was correlated with traditional prognostic factors and progression-free survival in endometrial cancer specimens.

RESULTS

EMA overexpression was observed more frequently in adenocarcinomas (60%) than in hyperplasias (15%) or benign endometrium (9.1%). EMA overexpression was observed in two patients with endometrial hyperplasia who progressed to carcinoma. In adenocarcinomas, EMA overexpression had a positive correlation with nonendometrioid subtypes (P = 0.012). In multivariate analysis, FIGO stage (P = 0.025) and EMA overexpression (P = 0.017) were independent prognostic factors for progression-free survival.

CONCLUSIONS

EMA overexpression appears to be a marker of malignant transformation in the endometrium and it is an independent predictor of recurrent disease in endometrial cancer.

Morphological identification of nitric oxide sources and targets in the cat oculomotor system

Nitric oxide (NO) production by specific neurons in the prepositus hypoglossi (PH) nucleus is necessary for the correct performance of eye movements in alert cats. In an attempt to characterize the morphological substrate of this NO function, the distribution of nitrergic neurons and NO-responding neurons has been investigated in different brainstem structures related to eye movements. Nitrergic neurons were stained by either immunohistochemistry for NO synthase I or histochemistry for reduced nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase. The NO targets were identified by cyclic guanosine monophosphate (cGMP) immunohistochemistry in animals treated with a NO donor immediately before fixation of the brain. Connectivity between cells of the NO-cGMP pathway was analyzed by injections of the retrograde tracers horseradish peroxidase or fast blue in different structures. The motor nuclei commanding extraocular muscles did not contain elements of the NO-cGMP pathway, except for some scattered nitrergic neurons in the most caudal part of the abducens nucleus. The PH nucleus contained the largest number of nitrergic cell bodies and a rich neuropil, distributed in two groups in medial and lateral positions in the caudal part, and one central group in the rostral part of the nucleus. An abundant cGMP positive neuropil was the only NO-sensitive element in the PH nucleus, where no cGMP-producing neuronal cell bodies were observed. The opposite disposition was found in the marginal zone between the PH and the medial vestibular nuclei, with a large number of NO-sensitive cGMP-producing neurons and almost no nitrergic cells. Both nitrergic and NO-sensitive cell bodies were found in the medial and inferior vestibular nuclei and in the superior colliculus, whereas the lateral geniculate nucleus contained nitrergic neuropil and a large number of NO-sensitive cell bodies. Some of the cGMP-positive neurons in the marginal zone and medial vestibular nucleus projected to the PH nucleus, predominantly to the ipsilateral side. These morphological findings may help to explain the mechanism of action of NO in the oculomotor system.

The relevance of flow cytometry for biochemical analysis

Flow cytometry (FCM) allows the simultaneous measurement of multiple fluorescences and light scatter induced by illumination of single cells or microscopic particles in suspension, as they flow rapidly through a sensing area. In some systems, individual cells or particles may be sorted according to the properties exhibited. By using appropriate fluorescent markers, FCM is unique in that multiple structural and functional parameters can be quantified simultaneously on a single-particle basis, whereas up to thousands of biological particles per second may be examined. FCM is increasingly used for basic, clinical, biotechnological, and environmental studies of biochemical relevance. In this critical review, we summarize the main advantages and limitations of FCM for biochemical studies and discuss briefly the most relevant parameters and analytical strategies. Graphical examples of the biological information provided by multiparametric FCM are presented. Also, this review contains specific sections on flow cytoenzymology, FCM analysis of isolated subcellular organelles, and cell-free FCM.

[Esophageal fibrovascular polyp: report of 2 cases]

Fibrovascular esophageal polyps are benign intraluminal tumors that, although of slow growth, may become large. We describe the features of two cases, diagnosed in our department, and emphasize the endoscopic aspects of the lesion.

Prognostic factors in invasive lobular carcinoma of the breast: a multivariate analysis. A multicentre study after seventeen years of follow-up

BACKGROUND AND GOALS

The purpose of this study was to characterize the biologic determinants that affect the behavior of invasive lobular carcinoma of the breast.

MATERIAL AND METHODS

A prospectively accrued data base containing 9,619 breast cancer cases was queried for specific pathological features. From this data base, 390 patients with invasive lobular carcinoma of the breast treated and followed at any of these three centers: San Carlos Hospital, Doce de Octubre Hospital or The Jimenez Diaz Foundation in Madrid (Spain) were reviewed and results, in terms of overall survival and disease-free survival were recorded for a long-term follow-up of 206 months (17 years).

RESULTS

The parameters that showed an important statistical influence on survival were the stage at diagnosis, the tumor size and nodal status, as well as the tumor grade. Age showed a limited influence, and multicentricity, or the type of surgical procedure had no statistical impact on survival.

CONCLUSIONS

Our analysis specifies the clinico-pathological features that influence the prognosis of invasive lobular carcinoma of the breast, and confirms that conservative therapy may be an appropriate treatment for this type of cancer.

[The prolonged administration of intravenous immunoglobulins as a treatment for refractory fistulous Crohn's diseases]

Fistulating Crohn's disease is present in 17-35% of non-surgically treated patients and in up to 45% of surgically treated ones. Among the several therapeutic alternatives for this disease is intravenous immunoglobulin administration. We present a 28-year-old woman with refractory fistulating Crohn's disease who improved after prolonged immunoglobulin administration (32 months).

Mechanisms of action and targets of nitric oxide in the oculomotor system

Nitric oxide (NO) production by neurons in the prepositus hypoglossi (PH) nucleus is necessary for the normal performance of eye movements in alert animals. In this study, the mechanism(s) of action of NO in the oculomotor system has been investigated. Spontaneous and vestibularly induced eye movements were recorded in alert cats before and after microinjections in the PH nucleus of drugs affecting the NO-cGMP pathway. The cellular sources and targets of NO were also studied by immunohistochemical detection of neuronal NO synthase (NOS) and NO-sensitive guanylyl cyclase, respectively. Injections of NOS inhibitors produced alterations of eye velocity, but not of eye position, for both spontaneous and vestibularly induced eye movements, suggesting that NO produced by PH neurons is involved in the processing of velocity signals but not in the eye position generation. The effect of neuronal NO is probably exerted on a rich cGMP-producing neuropil dorsal to the nitrergic somas in the PH nucleus. On the other hand, local injections of NO donors or 8-Br-cGMP produced alterations of eye velocity during both spontaneous eye movements and vestibulo-ocular reflex (VOR), as well as changes in eye position generation exclusively during spontaneous eye movements. The target of this additional effect of exogenous NO is probably a well defined group of NO-sensitive cGMP-producing neurons located between the PH and the medial vestibular nuclei. These cells could be involved in the generation of eye position signals during spontaneous eye movements but not during the VOR.

Prognostic value of motor evoked potential obtained by transcranial magnetic brain stimulation in motor function recovery in patients with acute ischemic stroke

BACKGROUND AND PURPOSE

The early prognostic application of transcranial magnetic brain stimulation (TMS) for assessing motor and functional recovery in ischemic stroke patients has yielded contradictory results. We performed a prospective study of patients with acute ischemic stroke and motor deficit to evaluate the early prognostic value of TMS in motor and functional recovery.

METHODS

Fifty patients with different degrees of hemiparesis were studied in the first week after ischemic stroke and evaluated by clinical scales (Medical Research Council Scale, Canadian Neurological Scale, Barthel Index), with clinical follow-up over 6 months. TMS (Magstim 200) was performed at the same time, recording the motor evoked potential (MEP) in the thenar eminence muscles, with facilitation by voluntary contraction.

RESULTS

Of the total group of 50 patients, MEP was absent in 20 and present in 30 (17 with normal and 13 with delayed central conduction time [CCT]). The patients with MEP showed better motor and functional recovery than those without. The MEP provided information on patient recovery, regardless of the initial strength and/or Barthel values. The degree of recovery was better in those patients with normal CCT than in those with delayed CCT.

CONCLUSIONS

MEP obtained by TMS in patients with hemiparesis after acute ischemic stroke is useful as an early prognostic indicator of motor and functional recovery. This technique would allow the early identification of those patients who will have a good recovery, particularly among those with severe initial paresis.

Nitric oxide production by brain stem neurons is required for normal performance of eye movements in alert animals

Although nitric oxide (NO) is produced by discrete groups of neurons in the brain, participation of NO in premotor structures directly involved in reflexively evoked, sensory-motor functions has not been demonstrated so far. We now show that NO is a physiological mediator in the generation of a specific motor response in alert behaving animals. In the oculomotor system, numerous neurons expressing nitric oxide synthase (NOS) are located in the prepositus hypoglossi, a nucleus involved in the control of horizontal eye movements. Unilateral inhibition of NOS within this nucleus results in severe ocular nystagmus with slow phases directed to the contralateral side. Accordingly, local increases of NO or cyclic GMP produced a nystagmus in the opposite direction. It is concluded that a balanced production of NO by prepositus hypoglossi neurons is a necessary condition for the normal performance of eye movements in alert animals.

Discharge properties of brain stem neurons projecting to the flocculus in the alert cat. II. Prepositus hypoglossal nucleus

1. The aim of this study was to characterize the signals transmitted by the neurons of the nucleus prepositus hypoglossal (NPH) to the middle zone of the flocculus of the cat. The methods, the behavioral testing, and the animals used in this study were the same as those used in the accompanying paper on medial vestibular nucleus neurons. 2. The rostral two-thirds of the NPH was explored in alert animals with microelectrodes during stimulation of the middle zone of both flocculi. Discharges of neurons were analyzed during spontaneous eye movements (head fixed) and during horizontal vestibuloocular reflex (VOR) activity elicited by sinusoidal stimulation (10, 20, 30, or 40 degrees at 0.1 Hz). Forty neurons were found to be antidromically activated from only one or the other of the two flocculi (latency: 0.99 +/- 0.17 ms, mean +/- SD): 37 from the contralateral flocculus and 3 from the ipsilateral one. None of the neurons could be activated antidromically from both flocculi. Floccular stimulation never resulted in direct inhibition of these NPH neurons. 3. Of the 37 units antidromically activated from the contralateral flocculus, 26 were recorded sufficiently long to allow full quantitative analysis. Most of these (20 neurons) were classified as burst-tonic (BT) neurons. The BT neurons exhibited during each saccade made in one direction (the ON direction) a burst of spikes, and during postsaccadic fixation a tonic activity that increased with gaze displacement in the ON direction. The mean sensitivity of the neurons to eye velocity during the "ON" saccades was 3.3 +/- 1.6 spikes.s-1.deg-1.s-1. During intersaccadic fixation, the mean sensitivity to eye position was 3.6 +/- 2.5 spikes.s-1.deg-1. During the VOR, the majority showed modulation in relation to both eye position and eye velocity. The mean sensitivity to eye position during the VOR was 3.4 +/- 2.6 spikes.s-1.deg-1 (range: 0.2-8.1 spikes.s-1.deg-1). The mean sensitivity to eye velocity during the VOR was 2.1 +/- 1.3 spikes.s-1.deg-1.s-1. The mean phase lead of with respect to eye position was 16.4 +/- 6.8 degrees (range: 6.0-28.9 degrees). Eighty percent of the BT neurons behaved as type I neurons. Forty-seven percent of the BT neurons also presented some head velocity sensitivity (1.48 +/- 0.6 spikes.s-1.deg-1.s-1, mean +/- SD). 4. Other NPH cells antidromically activated from the contralateral flocculus were classified in two groups: bidirectional burst (BB) neurons (n = 4) and burst-driving (BD) neurons (n = 2). The BB neurons were characterized by a burst discharge during every horizontal saccade or VOR quick phase, irrespective of the direction. The mean sensitivity of the BB neurons to eye velocity during saccades was 3.3 +/- 7.8 (SD) spikes.s-1.deg-1.s-1. Both BD neurons increased their firing rate during the slow VOR phases induced by an ipsilateral rotation (type I neurons) and exhibited high-frequency bursts in association with ipsilaterally directed quick phases. 5. The results indicate that the main projection of the NPH onto the middle zone of the flocculus comes from contralaterally located type I BT neurons. Signals transmitted in this path associate a high sensitivity for eye velocity with a high sensitivity for eye position. This type of input is consistent with the suggestion that the main function of the flocculus is to control the gain of downstream reflexes and to perform a fine adjustment of the gaze holding command.

Discharge properties of brain stem neurons projecting to the flocculus in the alert cat. I. Medical vestibular nucleus

1. The aim of this study was to characterize the signals transmitted by neurons of the medial vestibular nucleus (MVN) to the middle zone of the flocculus in alert cats. 2. Bipolar stimulating electrodes were implanted into the middle zone of each flocculus, because this zone is known to be involved in the control of horizontal eye movements. Correct implantation of the stimulating electrodes was ensured by 1) recording of Purkinje cells whose activity was related to horizontal eye movements and 2) elicitation of slow abduction of the ipsilateral eye upon electrical stimulation. 3. The rostral two-thirds of the MVN were investigated by microelectrodes during stimulation of both flocculi. Antidromically activated neurons were found only in the central part of the explored area. Forty-four units were activated from the contralateral, eight from the ipsilateral flocculus. Neurons could never be activated from both flocculi. 4. Neurons included in this study were MVN neurons that had 1) to be antidromically activated from one flocculus and 2) to modulate their firing rate during the horizontal vestibuloocular reflex (VOR) elicited by sinusoidal stimulation (0.1 Hz; 10, 20, 30 or 40 degrees). The 39 neurons matching both criteria were classified in 2 groups: 22 neurons changed their firing rate during spontaneous horizontal eye movements (EM-neurons), 17 modulated their activity only during head rotation and were labeled vestibular-only neurons (VO-neurons). 5. Sufficient data were obtained from 13 EM-neurons to allow a quantitative analysis. Among those, 12 were activated from the contralateral and 1 from the ipsilateral flocculus. Their sensitivity to horizontal eye position during intersaccadic fixation was 3.54 +/- 2.75 (SD) spikes.s-1/deg. Eight EM-neurons behaved as type I neurons, five as type II neurons. During the slow phases of the VOR, all of these neurons combined some head-velocity sensitivity (1.50 +/- 0.43 spikes.s-1/deg.s-1) with some horizontal eye-position sensitivity (3.61 +/- 2.45 spikes.s-1/deg). Additionally, seven of these neurons presented a sensitivity to eye velocity (1.34 +/- 0.55 spikes.s-1/deg.s-1). The phase difference between the modulation of firing rate and eye position varied substantially between neurons. The observed phase lead with respect to eye position ranged from 2 to 110 degrees (41.9 +/- 31.8 degrees). 6. Sufficient data were obtained from 10 VO-neurons to allow a quantitative analysis. Among those, nine were activated from the contralateral and one from the ipsilateral flocculus. All of these neurons behaved as type I neurons. The sensitivity to head velocity was 1.64 +/- 1.07 spikes.s-1/deg.s-1. The phase lead of the modulation of spike activity with respect to head velocity ranged from 4.5 to 30.5 degrees (16.4 +/- 8.9 degrees). 7. We conclude that the MVN provides the horizontal zone of the flocculus (with a strong contralateral preference) with information about head velocity (through VO-neurons and EM-neurons) and about eye velocity and position (through EM-neurons).

Evaluation of flow injection sample to standard addition method for the inductively coupled plasma mass spectrometric determination of aluminium in biological tissues

An on-line flow injection sample to standard addition method was developed for the determination of aluminium in biological tissues by inductively coupled plasma mass spectrometry. The sample concentration is calculated from two transient signals obtained from the injection of the blank and the sample, using a standard solution as carrier. A flow injection manifold for the on-line injection of both solutions was used and a three-step flow injection programme allowing the two transient signals to be obtained in the same measurement process was applied. A microwave nitric acid digestion procedure in closed vessels was used for sample dissolution, and scandium was added as an internal standard to control plasma fluctuations and to correct for ion signal instability. Tissue samples from healthy rat brain, kidney, liver, lung and spleen were analysed to find their aluminium concentrations. Complete recoveries from rat liver tissue spiked with aluminium concentrations in the 0.5-10.0 micrograms g-1 level were achieved. The detection limit (3 sigma) referred to the solid sample was of 10 ng g-1 and the precision (RSD) was better than 1%. The accuracy of the proposed method was tested by determining the aluminium contents in two NIST Standard Reference Materials: SRM 1577b Bovine Liver and SRM 8414 Bovine Muscle Powder).

A quantitative study of electroencephalography, eye movements and neck electromyography characterizing the sleep-wake cycle of the guinea-pig

The qualitative and quantitative characteristics of cerebral cortex electrical activity, ocular motility and muscular activity were studied in six head-restrained guinea-pigs during wakefulness, slow-wave and paradoxical sleep. Animals were chronically implanted with bipolar electrodes in the obliquus capitis muscle for electromyographic recordings and epidurally through the parietal bones for electroencephalographic (EEG) recordings. Eye movements were recorded using the scleral search-coil technique. After postoperative recovery and a short period of habituation to immobilization, head-restrained animals exhibited a polyphasic sleep-wake cycle similar to what has already been described in the unrestrained guinea-pig. Paradoxical sleep periods of mean duration 110 +/- 42 s occurred at a mean interval of 32.2 +/- 7.2 min. Amplitude and frequency components of EEG activity were different for each state of vigilance. EEG amplitude was highest and frequency range lowest-with two well-defined peaks at 4 and 10 Hz-during slow-wave sleep. During paradoxical sleep, frequencies were higher and amplitudes lower than during wakefulness. Three types of eye movement intermingled with periods of ocular fixation were recorded: saccadic movements during wakefulness and paradoxical sleep, slow drifts during slow-wave sleep and paradoxical sleep, and a new type of eye movement-bursts of high-velocity eye oscillations during paradoxical sleep. Saccadic eye movements during paradoxical sleep were more frequent and showed higher velocities and amplitudes than during wakefulness. During paradoxical sleep the episodes of eye oscillation (8-14 Hz) occurred quite regularly every 1.6 s and had a mean duration of 1.4 s. During wakefulness, the obliquus muscle activity displayed a burst-tonic pattern. Bursting components were closely related to saccadic eye movements directed to the side of the recorded muscle. The muscle activity was predominantly tonic during slow-wave sleep and was completely absent during paradoxical sleep except for small bursts or twitches. These twitches were tightly synchronized with the occurrence of the rapid eye movements oriented towards the side of the recorded obliquus muscle, as during wakefulness. These results strongly suggest that paradoxical sleep is characterized by the oscillatory discharge of at least two neuronal populations: the brainstem saccadic generators and the tecto-reticular spinal network which underlies gaze-orienting behaviour during wakefulness. The occurrence of rhythmic discharges at approximately 11 Hz may explain the spinal motoneurons' inhibition during paradoxical sleep in order to avoid anarchic motor behavior. Whether these neuronal oscillations are simply an epiphenomenon or have functional implications remains to be determined.

Comparison of the effects of nerve growth factor and superoxide dismutase on vascular extravasation in experimental burns

Superoxide dismutase (SOD), a free-radical scavenger, inhibits the increase of vascular permeability in experimental burn lesions in rats. In this study the aim was to determine whether Nerve Growth Factor (NGF), which has been implicated in the modulation of some inflammatory reactions, behaves in an analogous way. The study compares the haematocrit (Ht) and haemoglobin (Hb) variations in three groups of rats treated respectively with saline solution, SOD and NGF, immediately after causing a 25 per cent dermal burn injury. Statistical comparison (Student's t test) of the Ht and Hb variations between the Control group (Ht and Hb increase) and the NGF group (Ht and Hb decrease), shows significant differences in the intervals between 15 and 60 min (P < 0.01) and between 60 and 120 min (P < 0.05). Although SOD is able to control extravasation in the immediate postburn period (basal-15 min), NGF has a comparable effect in subsequent periods. The overall action of NGF shows that this agent is able to maintain Ht and Hb values at basal levels even after 120 min postburn. These results seem to be the first evidence of an inhibitory effect of NGF on the vascular permeability in burn lesions.

Hypoglossal nerve conduction study by transcranial magnetic stimulation in normal subjects

The introduction of transcranial magnetic stimulation has allowed the study of conduction in the proximal portions and central pathways of the cranial nerves. A study is made of cranial nerve XII with transcranial magnetic stimulation at two levels, cortical and cisternal, registering the motor evoked potential by means of surface electrodes in contact with the upper face of the tongue. Motor evoked potentials were constantly observed on cortical stimulation, in a painless, easy, and reproducible way, with mean values of 10.84 +/- 1.14 milliseconds (latency) and 7.81 +/- 1.14 mV (amplitude). Motor evoked potentials were unconstant and showed reduced amplitudes on cisternal stimulation, with mean values of 4.72 +/- 0.62 milliseconds and 0.83 +/- 1.26 mV. The magnetic stimulation technique allows the study of the entire motor pathway of cranial nerve XII (motor cortex-medulla, motoneuron-muscle). The method is efficient, noninvasive, painless, and easily reproduced, and it comes close to being an ideal clinical conduction study technique for this cranial nerve.