[Carotid stenosis and lacunar infarct]

INTRODUCTION

Perforating artery disease is still the main cause of lacunar infarcts (LI), while the relationship between this type of ischemia and carotid stenosis (CS) is controversial.

OBJECTIVE

To assess the association between CS and LI in patients with criteria of localized ischemia in the carotid territory separately analyzing isolated LI and multiples LIs.

PATIENTS AND METHODS

Three hundred and thirty patients with a first episode of cerebral infarct in the area supplied by the carotid artery were registered prospectively. There were 205 LI (135 isolated and 70 multiple) which could be differentiated from 125 non-lacunar infarcts (NLI). The vascular risk factors were determined and the degree of carotid stenosis measured by duplex-colour ultrasound exploration.

RESULTS

In the isolated LI group the frequency of presentation of CS greater than 50% was 22% for the artery ipsilateral to the LI and 8% for the contralateral artery. For significant CS (> 70%) frequencies of 14% (ipsilateral) and 8% (contralateral) were observed. On comparative analysis with the NLI group, the presence of stenosis greater than 50 to 70% was significantly higher in these for both ipsilateral and contralateral arteries. In the LI group, isolated CS was significantly more frequent on the side which was homolateral to the ischemia as compared to its isolated presence on the contralateral side (22/30 vs 4/12; OR: 5.5 [95% CI: 1.2-23]). Ipsilateral CS greater than 70% behaved as a factor which was significantly associated with the multiple LI subtype with a unilateral pattern.

CONCLUSION

CS should be considered a risk factor for LI.

Increased number of chromosomal imbalances and high-level DNA amplifications in mantle cell lymphoma are associated with blastoid variants

Mantle cell lymphomas (MCLs) are characterized by 11q13 chromosomal translocations and cyclin D1 overexpression. The secondary genetic and molecular events involved in the progression of these tumors are not well known. In this study, we have analyzed 45 MCLs (32 typical and 13 blastoid variants) by comparative genomic hybridization (CGH). To identify the possible genes included in the abnormal chromosome regions, selected cases were analyzed for P53, P16(INK4a), RB, C-MYC, N-MYC, BCL2, BCL6, CDK4, and BMI-1 gene alterations. The most frequent imbalances detected by CGH were gains of chromosomes 3q (49%), 7p (27%), 8q (22%), 12q (20%), 18q (18%), and 9q34 (16%) and losses of chromosomes 13 (44%), 6q (27%), 1p (24%), 11q14-q23 (22%), 10p14-p15 (18%), 17p (16%), and 9p (16%). High-level DNA amplifications were identified in 11 different regions of the genome, predominantly in 3q27-q29 (13%), 18q23 (9%), and Xq28 (7%). The CGH analysis allowed the identification of regional consensus areas in most of the frequently involved chromosomes. Chromosome gains (P =. 02) and losses (P =.01) and DNA amplifications (P =.015) were significantly higher in blastoid variants. The significant differences between blastoid and typical tumors were gains of 3q, 7p, and 12q, and losses of 17p. CGH losses of 17p correlated with P53 gene deletions and mutations. Similarly, gains of 12q and high-level DNA amplifications of 10p12-p13 were associated with CDK4 and BMI-1 gene amplifications, respectively. One of 2 cases with 8q24 amplification showed C-MYC amplification by Southern blot. Alterations in 2p, 3q, 13, and 18q were not associated with N-MYC, BCL6, RB, or BCL2 alterations, respectively, suggesting that other genes may be the targets of these genetic abnormalities in MCLs. Increased number of gains (0 v 1-4 v >4 gains per case) (P =.002), gains of 3q (P =.02), gains of 12q (P =.03), and losses of 9p (P =. 003) were significantly associated with a shorter survival of the patients. These results indicate that an increased number of chromosome imbalances are associated with blastoid variants of MCLs and may have prognostic significance.

Disregulation of p16MTS1/CDK4I protein and mRNA expression is associated with gene alterations in squamous-cell carcinoma of the larynx

To determine the relationship between p16MTS1/CDK4I expression, gene inactivation and 9p21 loss of heterozygosity (LOH) in the development of laryngeal carcinomas, we have examined p16MTS1/CDK4I protein and mRNA expression in a series of 7 normal and 36 tumoral tissues, and the presence of gene alterations and 9p21 LOH. Fifteen tumors (42%) showed low levels of pl6MTS1/CDK4I protein expression (similar to normal samples), 7 carcinomas (19%) expressed higher levels, and no protein expression was seen in 14 tumors (39%). No gene alterations were detected in 11 of the 15 tumors (73%) with protein levels similar to normal tissues. Most of the cases with absence of protein expression (86%) had gene alterations. Of the 7 tumors with protein over-expression, 4 showed frameshift or point mutations (2 cases each). mRNA analysis showed pl6MTS1/CDK4I -gene expression in 12 of 17 carcinomas examined. Gene alterations were detected in 9 of the 12 mRNA-positive tumors and in 2 of the 5 negative carcinomas. Concordant expression of p16alpha and p16beta transcripts was observed in all tumors. 9p21 LOH was detected in 23 carcinomas, 18 of which (78%) showed associated p16MTS1/CDK4I -gene alterations. These results indicate that disregulation of p16MTS1/CDK4I protein and mRNA expression is a frequent phenomenon in laryngeal carcinomas commonly associated with gene alterations and 9p21 LOH. The relative number of discrepancies between protein and mRNA expression and the presence of genetic alterations indicate that a comprehensive study of the gene including all these parameters may be necessary to assess the role of this gene in the pathogenesis of such tumors.

Bilateral lymphocytic alveolitis: a common reaction after unilateral thoracic irradiation

The main aim of the present study was to assess the early diagnostic value of bronchoalveolar lavage (BAL) in radiation-induced lung injury in patients with breast carcinoma. Twenty-six females receiving postoperative radiotherapy for breast cancer were evaluated before and 0, 15, 30, 60, and 180 days after radiotherapy. History, physical examination, chest radiographs, and pulmonary function tests were obtained. BAL, including lymphocyte subsets analysis, was limited to the second evaluation after radiotherapy. A group of 21 healthy females were used as control. Findings after radiotherapy in asymptomatic patients were compared with findings in a group of patients with radiation pneumonitis. Irradiated patients showed a significantly (p<0.01) greater percentage (29.5+/-15.7%) of BAL lymphocytes than controls (6.2+/-3.3%). No statistical differences existed in BAL findings between the irradiated and unirradiated sides of the chest. Percentages of BAL lymphocytes did not differ significantly between patients who developed subsequent pneumonitis (24.5+/-13.5%) and those who did not develop pneumonitis (32.8+/-16.5%). Patients with pneumonitis at the time of BAL had significantly higher (p<0.05) alveolar CD4 subset cells (24.8+/-10.2%) than asymptomatic patients (15.2+/-8.9%). Maximal reductions in total lung capacity (p<0.01), and residual volume (p<0.05) occurred 60 days after irradiation. The early lymphocytic alveolitis induced by unilateral thoracic radiotherapy in most patients with breast cancer is always bilateral and does not predict the subsequent development of radiological evidence of pneumonitis.

Antipsychotic drugs and reproductive hormones: relationship to body weight regulation

Excessive body weight gain is an undesirable side effect of prolonged administration of antipsychotic drugs (AP), which affects health and interferes with treatment compliance. It has been suggested that hyperprolactinemia-induced endocrine and metabolic abnormalities, particularly in the gonadal steroids, might be involved in the development of this type of weight gain. To test this hypothesis, reproductive hormones, cortisol, dehydro-epiandrosterone-sulfate (DHEA-S), thyroid hormones, and body weight gain were assessed in 18 patients (9 men, 9 women) with mental disorders receiving AP who had been medication-free for at least 3 months before the study, and in 27 placebo-treated subjects (10 men, 17 women). In women, hormones were evaluated during several phases of the menstrual cycle. A significant weight gain was observed in men but not in women. Under AP administration, women displayed significantly lower serum levels of estradiol and progesterone, whereas in men the levels of free testosterone and DHEA-S were significantly lower than in controls. Hyperprolactinemia was observed in both sexes. The levels of follicle-stimulating hormone in women and luteinizing hormone in men were significantly elevated by treatment, thus suggesting that the functioning of the hypothalamus-pituitary gonads was preserved. In men, such an endocrine profile resembles that observed in subjects with primary obesity. Women under AP administration were found to be relatively hyperandrogenic because of decreased serum estradiol levels, whereas women with primary obesity are known to display actual increased levels of androgens. These endocrine abnormalities may contribute to the excessive weight gain observed after AP treatment, and these could be the target of novel pharmacological treatments.

Glucose tolerance and serum insulin levels in an animal model of obesity induced by sub-acute or chronic administration of antipsychotic drugs

1. To assess the role of insulin in the development of the obesity induced by antipsychotic drugs, a glucose tolerance test was conducted in female rats after 0 or 30 days of sulpiride administration. 2. At day 10, the area under the glucose curve did not differ between sulpiride and vehicle-treated rats, however, the area under the insulin curve was significantly decreased by sulpiride. At day, 30 the insulin response was similar in both groups, but the area under the glucose curve was significantly lower in the sulpiride-treated rats. 3. The results suggest that insulin resistance and hyperinsulinemia are not involved in the development and maintenance of the obesity induced by sulpiride. Contrarily, these findings may be related to an increased insulin sensitivity. 4. The absence of hyperinsulinemia and insulin resistance indicates important differences between primary obesity in humans and rodents and this model of drug-induced excessive weight gain.

Evidence of the effectiveness of continuous positive airway pressure in the treatment of sleep apnea/hypopnea syndrome

Continuous positive airway pressure (CPAP) is worldwide considered as the standard treatment of sleep apnea/hypopnea syndrome (SAHS) although studies on the effectiveness of this treatment are limited. The aim of our study was to evaluate the effectiveness of CPAP in improving SAHS-related symptoms, daytime function, perceived health status, and quality of life in patients with moderate to severe SAHS. The effect of conservative treatment (CT) measures-sleep hygiene and weight loss- was compared with CT + CPAP. We included 105 consecutive patients (13 females, age 53 +/- 10 yr, body mass index [BMI] = 32 +/- 6 kg/m2, apnea/hypopnea index [AHI] = 56 +/- 20, Epworth sleepiness scale [ESS] = 12 +/- 5) who met our criteria for CPAP treatment. Patients were randomly allocated in two groups of similar characteristics. Group 1 (n = 37) was asked to improve sleep hygiene and started a weight loss program. Group 2 (n = 68) received, in addition, treatment with CPAP. Both groups were followed through weekly telephone calls and appointments. Sleepiness, other symptoms related to SAHS, daytime function, perceived health status, and quality of life were assessed through questionnaires at inclusion and after 3 mo of treatment. The relief of sleepiness and other SAHS-related clinical symptoms and improvement in perceived health status was much greater in Group 2 receiving CT + CPAP compared with Group 1, only receiving CT. The odds of experiencing a treatment response with CPAP + CT compared with CT alone was 6.52 (odds ratio [OR] = 2.51 to 17.6, 95% confidence interval [95% CI]). CPAP is currently the treatment of choice. At this time, the indication of CPAP treatment in moderate to severe SAHS is adequately supported.

Substitution of Asp-309 by Asn in the Arg-Asp-Pro (RDP) motif of Acetobacter diazotrophicus levansucrase affects sucrose hydrolysis, but not enzyme specificity

beta-Fructofuranosidases share a conserved aspartic acid-containing motif (Arg-Asp-Pro; RDP) which is absent from alpha-glucopyranosidases. The role of Asp-309 located in the RDP motif of levansucrase (EC 2.4.1.10) from Acetobacter diazotrophicus SRT4 was studied by site-directed mutagenesis. Substitution of Asp-309 by Asn did not affect enzyme secretion. The kcat of the mutant levansucrase was reduced 75-fold, but its Km was similar to that of the wild-type enzyme, indicating that Asp-309 plays a major role in catalysis. The two levansucrases showed optimal activity at pH 5.0 and yielded similar product profiles. Thus the mutation D309N affected the efficiency of sucrose hydrolysis, but not the enzyme specificity. Since the RDP motif is present in a conserved position in fructosyltransferases, invertases, levanases, inulinases and sucrose-6-phosphate hydrolases, it is likely to have a common functional role in beta-fructofuranosidases.

Plasma serotonin monitoring by blood microdialysis coupled to high-performance liquid chromatography with electrochemical detection in humans

Plasma serotonin (5-HT) active pool was monitored in male volunteers by intravenous microdialysis coupled to HPLC-EC with 98.6% efficient probes. 5-HT was monitored from 60 min before to 360 min after an oral dose of fluoxetine, a 5-HT uptake inhibitor, or vehicle. The basal values were within nanomolar range (0.55 to 4.6 ng/ml). After administration of fluoxetine, there was a significant increment of 5-HT with respect to controls. These results showed that intravenous microdialysis is an alternative efficient technique to monitor endogenous unbound 5-HT changes in plasma without extracting blood or sample pretreatment procedures before the chemical analysis.

In vivo monitoring of gabapentin in rats: a microdialysis study coupled to capillary electrophoresis and laser-induced fluorescence detection

Gabapentin (GP) is a new anticonvulsant used in refractory epilepsy. Few studies have monitored the drug in vivo. We report the combination of capillary electrophoresis and laser-induced fluorescence detection (CZE-LIFD) with brain microdialysis and plasma ultrafiltration in an attempt to measure GP and offer an alternative technique for pharmacokinetic studies. We found that CZE-LIFD is capable of linearly measuring 10(-7)-10(-9) M GP in a 1 nL volume. It was also demonstrated that it is possible to monitor GP in prefrontal cortex dialysates and plasma in rats. It is concluded that the method permits in vivo monitoring of the drug in pharmacological as well as in clinical studies.

Collagenase-3 expression is associated with advanced local invasion in human squamous cell carcinomas of the larynx

Collagenase-3 (MMP-13) is a matrix metalloproteinase recently identified on the basis of differential expression in normal breast tissues and in breast carcinoma. To date, collagenase-3 expression has been reported only in breast carcinomas and in articular cartilage of arthritic patients; the presence and possible implication of this enzyme in the progression of other malignant tumours are unknown. In this study collagenase-3 mRNA expression has been analysed by northern blot in a series of 35 matched squamous cell carcinomas of the larynx and the corresponding adjacent non-neoplastic tissues. In addition, mRNA expression of membrane type 1-matrix metalloproteinase (MT1-MMP) and gelatinase A, two matrix metalloproteinases which have the ability to activate collagenase-3 in vitro, was also examined in the same cases. No collagenase-3 expression was detected in any of the 35 normal mucosae, but collagenase-3 mRNA was observed in 20 of the 35 carcinomas (57 per cent). Western blot analysis revealed the presence of collagenase-3 protein in those carcinomas with high levels of mRNA expression, whereas no protein was detected in the carcinomas with negative mRNA expression, or in any of the normal tissues. The protein was localized predominantly in tumour epithelial cells. Collagenase-3 expression correlated significantly with better histological differentiation of the tumours (p = 0.026), as well as with advanced local invasion (p = 0.026). Collagenase-3 upregulation was also significantly associated with MT1-MMP and gelatinase A overexpression. These findings suggest that collagenase-3 expression may contribute to the progression of a significant subset of squamous cell carcinomas of the larynx and that its coordinate overexpression with MT1-MMP and gelatinase A may have a cooperative effect in the progression of the tumours.

Glucose tolerance and serum insulin levels in an animal model of obesity induced by the antipsychotic drug, sulpiride

To assess the role of insulin in the development of obesity induced by antipsychotic drugs, a glucose tolerance test was conducted in 40 female rats during the peak of sulpiride-induced weight gain and in 40 vehicle-treated animals. The glucose area under the curve did not differ between the groups (P = 0.24), however, the area under the insulin curve was significantly decreased by sulpiride (55.2 +/- 2.8 versus 115.6 +/- 18.9, P = 0.007). The results suggest that insulin resistance and hyperinsulinaemia are not involved in the excessive weight gain observed in this animal model of drug-induced obesity. Alternatively, the insulin-dampened response observed in the sulpiride-treated rats may be related to increased insulin sensitivity, which may promote weight gain as proposed by Ravussin (1995).

Buckling of cylinders may cause prolonged penile pain after prosthesis implantation: a case control study using magnetic resonance imaging of the penis

PURPOSE

We identify risk factors associated with chronic postoperative penile pain after inflatable prosthesis insertion.

MATERIALS AND METHODS

We performed a case control study to determine the incidence of prolonged penile pain in 65 men who underwent prosthesis insertion. The association of various potential risk factors, including diabetes mellitus, incision site, prosthesis type, patient age and history of pelvic surgery, was assessed. In addition, the penis was examined for physical findings, and penile magnetic resonance imaging (MRI) was done as an in situ evaluation of the anatomical position and functional status of the inflatable prosthesis.

RESULTS

A total of 14 patients (21.5%) with prolonged pain were compared to the remaining 51 with no pain. All parameters evaluated were similar in both groups except for MRI findings. Of the 14 patients with pain 12 (85.7%) had buckling of the cylinders in the flaccid state compared to only 1 of the 51 controls (1.9%). Statistical analysis showed a highly significant association between buckling and penile pain (odds ratio 300, p <0.0001). Surgical correction of buckling resolved pain in 5 patients.

CONCLUSIONS

Prolonged postoperative penile pain after prosthesis insertion is strongly associated with cylinder buckling. This buckling may be the consequence of an excessively long cylinder or an appropriate size cylinder that fails to reach the crural end. The method of accurately diagnosing these alterations is MRI of the penis.

Functional Bradyrhizobium japonicum NifA expression under a hybrid nptII-nifH promoter in E. coli and Acetobacter diazotrophicus SRT4

A hybrid promoter consisting of the in tandem fusion of the Tn5 nptII and the Klebsiella pneumoniae nifH promoters was constructed to study the functionality of the nif genes transcriptional activator NifA from Bradyrhizobium japonicum in two different host bacteria. beta-galactosidase experiments in E. coli revealed that the hybrid nptII-nifH promoter can behave as a constitutive or a NifA-inducible promoter depending on the aeration conditions. Expression of the B. japonicum NifA from the hybrid nptII-nifH promoter (plasmid pBPF204) induced "in trans" lacZ transcription from the Azotobacter chroococcum nifH promoter in E. coli and A. diazotrophicus cells grown at low pO2. Similarly, the plasmid pBPF204 increased nitrogenase activity in A. diazotrophicus cells grown under microaerobic conditions. Based on these results, we suggest that the B. japonicum NifA could function as an efficient O2-sensitive transcriptional activator of nif genes in genetically distant diazotrophic bacteria.

Importance of the pulse oximeter averaging time when measuring oxygen desaturation in sleep apnea

The accuracy of pulse oximeters in measuring transient changes in oxygen saturation (SaO2) may be affected by the oximeter time response. The aim of this study was to assess the effect of modifying the pulse oximeter averaging time (T) on the measurement of SaO2 in patients with the sleep apnea-hypopnea syndrome (SAHS). Twelve patients with severe SAHS were studied during a nap with conventional oximeters: Ohmeda 3740 and Criticare 501. We compared the readings of each patient's oxygen desaturation measured simultaneously with two identical pulse oximeters. One oximeter was the control (T = 3 seconds), and in the other T was set from 3 seconds to 21 seconds. No significant differences in SaO2 were found when both oximeters were set to the same T (3 seconds). In contrast, increasing T to 12 seconds and 21 seconds in one of the oximeters resulted in considerable and significant differences in the measured SaO2: oxygen desaturation was underestimated by up to 60% when compared with the control. The misestimation of SaO2 induced by settings of T which are within the range selectable in conventional oximeters may be of epidemiological significance when pulse oximetry is used as a complementary diagnostic tool to classify sleep events in SAHS.

Diagnostic imaging of lipoma arborescens

OBJECTIVE

The imaging characteristics of lipoma arborescens using plain radiographs, computed tomography (CT), and magnetic resonance imaging (MRI) are described.

DESIGN AND PATIENTS

Five patients with a diagnosis of lipoma arborescens are presented. Three had monoarticular involvement of the knee joint. In the remaining two patients both knees and both hips, respectively, were affected. All patients were examined using plain radiographs and MRI. CT was employed in two cases.

RESULTS AND CONCLUSIONS

A conclusive diagnosis with exclusion of other synovial pathologies having similar clinical and radiological behavior can be achieved on the basis of the MRI characteristics of lipoma arborescens. The aetiology of lipoma arborescens remains unknown, but its association with previous pathology of the affected joints in all our patients supports the theory of a non-neoplastic reactive process involving the synovial membrane.

Tuberculous pleurisy with or without radiographic evidence of pulmonary disease. Is there any difference?

SETTING

A community teaching hospital in Alicante, Spain.

OBJECTIVE

To assess the characteristics of tuberculous pleurisy (TP) in our hospital, and to evaluate the differences between primary and reactivation forms.

DESIGN

Between January 1984 and December 1993, all human immunodeficiency virus (HIV)-negative patients with TP were included in the study. From September 1987 onward, patients were prospectively studied. Charts, radiography, pleural fluid findings and diagnostic methods were evaluated. Two groups were distinguished according to chest radiographs: those patients with upper lobe lesions, calcified adenopathy and old pleural thickening were considered reactivation forms.

RESULTS

Of the 129 patients (mean age, 31 +/- 18 years), 76% had primary TP and 24% reactivation TP. Differences were found in age (28 +/- 17 vs 40 +/- 18 years, P < 0.01), smoking (43% vs 74%, P < 0.01) and alcohol abuse (23% vs 47%, P < 0.05), weight loss (29% vs 50%, P < 0.05), positive sputum smears and cultures (2% vs 16%, 7% vs 28%, P < 0.01), and number of large effusions (46% vs 26%, P < 0.05), but not in tuberculin reactivity, pleural fluid findings, positive pleural cultures, or presence of pleural granuloma.

CONCLUSION

In our setting, TP predominantly affects young adults. Clinical, immunological, and pleural findings are similar to those of patients with classic symptoms of TP. Older age, smoking and alcohol abuse, smaller effusions and sputum yield are differential characteristics of reactivation forms.

cdc25 cell cycle-activating phosphatases and c-myc expression in human non-Hodgkin's lymphomas

cdc25A, cdc25B, and cdc25C are a family of human phosphatases that activate the cyclin-dependent kinases at different points of the cell cycle. cdc25A and cdc25B have been shown to have oncogenic potential, and they have been identified as transcriptional targets of c-myc. To determine the role of cdc25 genes in the pathogenesis of human lymphomas and their possible correlation with c-myc deregulation, we have analyzed the expression of cdc25A, cdc25B, and cdc25C and c-myc genes in a series of 63 non-Hodgkin's lymphomas and 8 nonneoplastic lymphoid tissues. The mRNA levels of the three phosphatases in the nonneoplastic tissues were negative or negligible. cdc25B overexpression was detected in 35 tumors (56%). This overexpression was more frequently found in aggressive (81%) than in indolent lymphomas (36%; P < 0.01). cdc25B overexpression was also significantly associated with a higher proliferative activity of the tumors. No cdc25B gene amplification or rearrangements were detected by Southern blot analysis. A biallelic EcoRI polymorphism of cdc25B gene was identified with a similar distribution in patients with lymphoma and in a normal population. cdc25A was overexpressed in three aggressive lymphomas. No detectable cdc25C mRNA levels were seen in any of the tumors. c-myc was overexpressed in 43% of tumors, and it correlated significantly with the presence of cdc25B up-regulation. Twenty-six of 35 (74%) lymphomas with high levels of cdc25B mRNA also showed c-myc overexpression, whereas 27 of 28 (96%) tumors without detectable or with very low cdc25B expression also had undetectable c-myc levels (P < 0.0001). In addition, a significant linear correlation was found between the cdc25B and c-myc mRNA levels (r = 0.575, P < 0.001). These findings suggest that cdc25B overexpression in non-Hodkin's lymphoma may participate in the pathogenesis of aggressive variants, and it may cooperate with c-myc oncogene in the development of these tumors.