Diagnosis and treatment of hepatocellular carcinoma

Several advances have been produced in the diagnosis and treatment of patients with hepatocellular carcinoma. It is possible to diagnose the neoplasm at an early stage when radical treatment options may be applied. The criteria to apply them successfully have been refined and the expected outcome has been improved, but we still lack a useful treatment for the vast majority of patients who are still diagnosed at an advanced stage. Efforts have to be done during the next years to develop such an option (perhaps based on gene manipulation) and until then the management of this tumour will still constitute a challenge for physicians taking care of patients with this neoplasm.

Torsional stability of primary total knee replacement tibial prostheses: a biomechanical study in cadaveric bone

The significance of torsional loads on the tibial component of total knee replacement prostheses is not clearly established. This study investigated the micromotion induced by torsion, under physiologic loads. Three forms of fixation were sequentially tested in cadaveric tibiae: press-fit, press-fit plus 4 peripheral corticocancellous screws, and horizontally cemented. The implanted tibia was loaded with an axial force between 0.5 and 2.2 kN and a cyclic torque of +/- 5 Nm. The relative motion between the prosthesis and the bone was measured. Our results show little difference between the 3 methods of fixation at high axial loads. At low axial loads, however, the press-fit prosthesis may permit micromotions high enough to interfere (theoretically) with bone ingrowth. Motion is reduced when the same prosthesis is augmented with screws. The cemented prosthesis produces the lowest average micromotion. Our study indicates that rotational micromotion is unlikely to contribute to the failure of ingrowth into the uncemented tibial prosthesis under normal physiologic loads. At low axial loads, which may be encountered in the immediate postoperative period, ingrowth may be compromised. Thus, initial rotational stability is an important consideration in uncemented total knee replacement design and postoperative management. In poor-quality tibiae, cementation may be the only method of fixation to provide sufficient torsional stability.

Tumour markers CEA, NSE, SCC, TPA and CYFRA 21.1 in resectable non-small cell lung cancer

BACKGROUND

In the last few years, several prognostic factors have been investigated in order to identify among patients with completely resected non-small cell lung cancer (NSCLC) subsets at high risk of recurrence. In this context, the actual role of serum tumour markers is still unclear. The aim of this study was to evaluate the prognostic significance of preoperative CEA, NSE, SCC, TPA and CYFRA 21.1 serum levels in 62 patients submitted to radical surgery for non-small cell lung cancer (NSCLC). The predicting ability of these tumour markers with respect to histological type and pathological stage was also assessed.

PATIENTS AND METHODS

After informed consent was obtained, the preoperative serum concentrations of the tumour markers CEA, NSE, SCC, TPA and CYFRA 21.1 were measured by means of immunometric assays in 62 patients referred to our Institutions from January to December 1992. All patients had resectable, histologically proven NSCLC and were submitted to radical surgery. Overall survival (OS) was calculated as the time elapsed from surgery to the date of death or last clinical evaluation; the prognostic effect of the tumour markers was investigated by Cox multiple regression models.

RESULTS

Fifty-six patients were male and 6 female; median age was 62 years. Thirty-four patients had a histological diagnosis of adenocarcinoma and 28 of squamous cell carcinomas. With regard to pathological stage, 32 patients had stage I, 4 patients had stage II and 23 patients had stage IIIA disease. In this series of patients, at a median follow-up of 55 months after surgery, we found that both TPA and CYFRA 21.1 serum levels at the time of diagnosis were reliable predictors of overall survival high values of these markers being associated with worse prognosis.

CONCLUSIONS

Our findings suggest that in completely resected NSCLC, TPA and CYFRA 21.1 preoperative serum levels might provide a useful tool for stratifying subgroups of patients with different chances of disease recurrence after surgery.

New case of the Richieri-Costa/Guion-Almeida syndrome

We describe a boy with multiple congenital anomalies/mental retardation (MCA/MR) syndrome. He has growth retardation, microbrachycephaly, coloboma of the iris, and typical facial anomalies including cleft lip/palate. This phenotype overlaps with that described by Richieri-Costa and Guion-Almeida in three Brazilian brothers. The new patient provides further evidence of the existence of this rare clinical entity.

Urinary porphyrin excretion in a human population highly exposed to hexachlorobenzene

BACKGROUND

Data from an epidemic reported in Turkey (1955-1959) is the only information about the relationship between hexachlorobenzene (HCB) intake and porphyria cutanea tarda in humans. No information is available on the HCB threshold exposure level to induce porphyria cutanea tarda.

OBJECTIVES

To study HCB serum levels and urinary porphyrin excretion in the inhabitants of a village located near an organochlorine compound factory with high HCB concentrations in the air and to detect possible alterations in urinary porphyrin excretion and examine their relationship with HCB serum levels.

DESIGN

Cross-sectional study.

SETTING

Unit of Porphyrias of a tertiary care facility in Barcelona, Spain.

PARTICIPANTS

Six hundred four inhabitants of the village who were older than 14 years provided serum and urine samples (185 participants were factory workers).

MAIN OUTCOME MEASURES

Serum HCB was analyzed by gas chromatography coupled to electron capture detection. Quantification of urinary total porphyrins was performed by spectrofluorimetry. Porphyrin profile was determined by high-pressure liquid chromatography.

RESULTS

Hexachlorobenzene was detected in all serum samples (mean, 39.8 ng/mL; range, 1.1-1616.0 ng/mL), and levels were higher in factory workers. Mean +/- SD level urinary total porphyrin average concentration was 98 +/- 69 nmol/L (range, 9-1009 nmol/L). Only the urine sample with the highest porphyrin concentration showed an increase of highly carboxylated porphyrins, with a typical profile of porphyria cutanea tarda. In the remaining 603 urine samples, coproporphyrin was the predominant fraction.

CONCLUSION

The airborne exposure to and increased body burden of HCB in the Flix village population are not enough to trigger a significant alteration of the heme biosynthesis pathway.

Health effects of chronic high exposure to hexachlorobenzene in a general population sample

Hexachlorobenzene, an organochlorine compound that accumulates in humans, is widespread throughout the environment. In this study, we describe the health status of inhabitants of a rural village that surrounds an electrochemical factory characterized by high levels of hexachlorobenzene in the air. During 1994, we conducted a cross-sectional study of 1 800 inhabitants in the south of Catalonia, Spain, who were older than 14 y of age. We obtained information on lifestyles and occupational and medical histories via questionnaire. Self-reported health outcomes were validated against clinical records and cancer registry data. Serum levels of hexachlorobenzene were very high in males who worked in the electrochemical factory (geometric mean = 54.6 ng/ml in randomized participants). Levels were lower among subjects who had never worked in the electrochemical factory (females, 14.9 ng/ml; males, 9.0 ng/ml). Levels of other organochlorine compounds (i.e., beta-hexachlorocy-clohexane, 2,2-bis[p-chlorophenyl]-1,1-dichloroethylene) were in the same range found in other communities. Perceived health, prevalence of self-reported common chronic conditions, and porphyria cutanea tarda, thyroid pathology, Parkinson's disease, cancer, and reproductive outcomes were within the ranges observed in other studies. Employment in the plant, however, was associated with having any of the a priori selected health outcomes that were potentially related to exposure to hexachlorobenzene (odds ratio for cancer prevalence = 1.9; 95% confidence interval = 0.5, 7.6). Our population of workers and nonworkers had the highest levels of hexachlorobenzene ever described. The results suggest that exposure to hexachlorobenzene did not affect the general health status of the this population, but it was associated with specific health effects of the most highly exposed subjects.

Organochlorine in the serum of inhabitants living near an electrochemical factory

OBJECTIVES

To measure the impact of occupational and lifestyle factors on concentrations of organochlorine compounds in a general population sample living near an electrochemical factory with a high airborne concentration of hexachlorobenzene (HCB).

METHODS

Serum samples from 608 people (328 selected from a random sample) were collected in 1994. Information on lifestyles, occupation, and medical condition was obtained by questionnaire.

RESULTS

HCB and polychlorinated biphenyls (PCBs) were detected in all samples (means 36.7 ng/ml and 4.3 ng/ml respectively), followed by dichlorodiphenyl dichloroethane (DDE) and beta-hexachlorocyclohexane (beta-HCH), found in 98.7% and 87.3% of the samples respectively (means 4.6 ng/ml and 2.5 ng/ml, respectively). Concentrations of HCB were the highest ever reported. Occupation in the factory was the main determinant of the variation in concentrations of HCB (regression coefficients 1.52 (SEM 0.14) in 1n (HCB) for workers in the production department, and 2.13 (0.23) for workers in maintenance department) and explained the highest concentrations of HCB found in men of middle age. In retired workers, concentrations of HCB declined with time since retirement. The PCBs, dichlorodiphenyl trichloroethane (DDT), and beta-HCH were independent of the occupation and concentrations were similar to those found in other populations. Concentrations of beta-HCH and DDE in the whole population, and HCB among non-workers, were higher in women than in men. Concentrations of all measured organochlorine compounds increased with age and body mass index. Consumption of locally caught fish was an independent determinant of HCB and PCB concentrations.

CONCLUSIONS

This population incorporated HCB directly through occupation in the electrochemical factory, by airborne pollution, and consumption of locally caught fish. Concentrations of other common organochlorine compounds were not higher than expected. Environmental exposures to these compounds deserve attention due to their persistence and potential health effects.

Natural history of untreated nonsurgical hepatocellular carcinoma: rationale for the design and evaluation of therapeutic trials

This study analyzed the natural history and prognostic factors of patients with nonsurgical hepatocellular carcinoma (HCC). Twenty variables from 102 cirrhotic patients with HCC who were not treated within prospective randomized controlled trials (RCT) were investigated through uni- and multivariate analyses. None of them was suitable for radical therapies (surgical resection, liver transplantation, or ethanol injection) or presented end-stage disease as reflected by an Okuda stage 3 or a Performance Status >/=3. Sixty-five patients were Child-Pugh A, 34 were B, and 3 were C. Most of them exhibited a preserved Performance Status Test (PST) (0 = 56; 1 = 38; 2 = 8). Tumor was solitary in 26 (</=5 cm in 16) and multinodular/massive in 76. After a median follow-up of 17 months, 79 patients died, the 1-, 2-, and 3-year survival being 54%, 40%, and 28%. The multivariate study identified PST (P =.01), constitutional syndrome (P =.04), vascular invasion (P =.001), and extrahepatic spread (P =.04) as independent predictors for mortality. The 1-, 2-, and 3-year survival for the 48 patients without adverse factors (Stage 0) was 80%, 65%, and 50%, respectively, and 29%, 16%, and 8% in the 54 patients with at least one adverse parameter (Stage I). Therefore, Stage 0 would correspond to an intermediate stage, while Stage I would represent an advanced status, before reaching an end-stage phase. In conclusion, the outcome of nonsurgical HCC is not homogeneously grim and may be predicted by assessing the presence of symptoms and of an invasive tumoral pattern. Therapeutic trials should be designed and evaluated considering these characteristics.

[Screening for colorectal cancer in Catalonia. Results of a population survey]

BACKGROUND

In recent years, the usefulness of programs for the prevention of colorectal cancer has been demonstrated in the general population as well as on specific risk groups. However, its implantation rate is unknown in our area. This study was aimed at evaluating the level of introduction of colorectal cancer screening.

METHOD

A telephonic survey has been carried out using a pre-established questionnaire to find out if the interviewed had undergone a fecal occult blood test, digital rectal examination, barium enema and/or colorectal endoscopy with the final aim of colorectal cancer prevention. Moreover, the knowledge of both above mentioned explorations and the colorectal cancer clinical manifestations have also been evaluated. Individual characteristics determining these aspects have also been investigated.

RESULTS

Only two (0.8%) of the 250 subjects included had undergone a screening procedure (digital rectal examination). In contrast, in female population, 142 women (82%) had been included in a surveillance program to detect early signs of breast or gynecological cancer. In addition, a low level of knowledge of these explorations has been observed (digital rectal examination: 58%; colorectal endoscopy: 56%; barium enema: 44%; fecal occult blood test: 41%). This low level was also observed regarding to clinical manifestations associated with colorectal cancer.

CONCLUSIONS

In contrast with gynecological cancer, colorectal cancer screening has not yet been introduced in Catalonia. Moreover, the knowledge of the available information regarding to preventive strategies is very low.

A novel method for self-administering addicting drugs intracerebroventricularly in a free-choice procedure

This paper describes a safe method for long term intracerebroventricular (i.c.v.) drug administration. Employing a non-preferred lever to control the self-administration the technique offers advantages over existing experimental methods. To check for any innate preference for one of two levers, male Wistar rats were allowed during the training procedure, to press two levers (L1 and L2) for one hour/day to obtain water as reinforcer for one week in a continuous reinforcement schedule (CRF). One week after surgery, during which a double-guide stainless steel cannula was inserted into both lateral ventricles, rats received 2 microliter of sterile cerebrospinal fluid (CEPH) each time they pressed one of two levers during the daily one-hour session. When a stable baseline was reached, rats were divided into three groups on the basis of their lever preference, and submitted to the testing procedure. A potent mu-opiate receptor agonist, etonitazene (0.1-0.2-1 microgram/infusion), was always associated with the non-preferred lever for each rat. When no obvious preference was shown for either lever the opiate was firstly delivered by L1(for 11 days) and then by L2 (for 20 days). The results indicate that, regardless of which lever had been preferred initially, the rats increased the pressing of only the lever associated with the opiate. The daily amount taken increased linearly and was behaviorally active. This model highlights for the first time the reinforcing properties of drugs given i.c.v. in a free-choice situation.

A death certificate-based study of occupation and mortality from reproductive cancers among women in 24 US states

We conducted a study of occupation and mortality from reproductive cancers among women, based on death certificates from 24 US states for the period 1984-1993. There were 9,523 cervical cancer deaths, 12,335 endometrial cancer deaths, and 25,212 ovarian cancer deaths. Usual occupation and industry, which were obtained from death certificates, were coded using the 1980 Bureau of Census classification system. Mortality odds ratios (MORs) and 95% confidence intervals (CIs) were calculated, using all non-cancer deaths as the referent disease category. In general, jobs involving professional or administrative occupations were related to increased risk of mortality from endometrial and ovarian cancer, while cervical cancer mortality was increased among women employed in manufacturing, service, farm work, and health care technician and aide occupations. Associations with some occupations involving exposure to chemicals and metals, such as the associations between cervical cancer and employment in printing, typesetting, and machine operating occupations, deserve further attention. Similarly, further investigations should be made into the excess of ovarian cancer observed in several occupations in health care, an industry that has numerous hazardous exposures, including radiation, chemotherapeutic drugs, and viruses. The study results reflect, in part, socioeconomic factors and reproductive patterns but may also indicate a possible etiologic role for occupational chemical exposures.

Long-lasting antiamnesic effect of a novel anticholinesterase inhibitor (MF268)

In the present study a short (120 min) and long-lasting (360 min) antagonism of scopolamine-induced amnesia in rats was investigated in an eight-arm radial maze, by (3a S, 8a R)-1,2,3,3a,8,8a-hexahydro-1,3a,8-trimethylpyrrolo[2,3-b]indol-5-o l[8-(cis2,6-dimethyl-morpholin-4-yl)octyl]-carbamate L-bitartrate hydrate (MF268), a new cholinesterase inhibitor. Upon completing the training session, the rats were orally administered increasing doses of MF268 (2, 3, 6, 7, and 8 mg/kg) 60 min prior to s.c. injection of scopolamine (0.25 mg/kg). Following a further 60 min the rat was placed in the maze. The reversal of scopolamine-induced impairment was characterized by an inverted U-shaped dose-response curve. A significant reduction in the number of errors, and time taken to complete the maze was observed with a dose of 6 mg/kg. The compound improved memory retention without affecting scopolamine-induced hypermotility. When the same dose was administered 360 min prior to the test a significant reduction in the number of amnesic animals was observed, whereas no cognitive improvement was detected when either 1-Benzil-4-[(5,6-dimethoxy-1-indanon)-2-yl]-methyl piperidine hydrochloride (E2020) (0.25 mg/kg) or tacrine (0.5 mg/kg) were administered 360 min prior to the test. The kinetics of whole-brain cholinesterase confirmed the long-lasting activity for MF268. A clinical relevance for the use of MF268 in AD treatment is suggested.

Vertebral fracture in a fused spine for scoliosis. A case report

STUDY DESIGN

A case report.

OBJECTIVES

To document a fracture of the 11th thoracic vertebra after spine fusion for adult idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

Three cases of vertebral fractures associated with spine fusion for scoliosis were found in the literature.

METHODS

Medical and radiologic records and related literature were reviewed.

RESULTS

A 30-year-old woman had undergone anterior and posterior fusion with Cotrel-Dubousset instrumentation for progressive idiopathic scoliosis. Two years after surgery, she was in a car accident. A radiographic study and computer tomographic scanning depicted a fracture of T11 and bending of the rods. Observation was instituted and symptoms resolved.

CONCLUSIONS

Fracture of a vertebra within an extensive spine fusion for scoliosis is rare. The 360 degrees solid fusion together with strong posterior instrumentation may have had some protective effect in this patient.

Original Digital Technique to Isolate Santorini'S Plexus and Membranous Urethra during Radical Retropubic Prostatectomy and Radical Cystectomy

The authors give the results obtained with their digital technique for isolating Santorini's plexus during radical retropubic cystectomy or radical prostatectomy. Objectives: to reduce bleeding during surgery; to respect anatomic structures; greater safety during resection of the urethra; to respect the neurovascular erectile bundles; to assess post-operative erection. This technique was used in 46 operations (32 cystectomies and 14 radical prostatectomies) between January 1997 and February 1998. Blood loss from the plexus was 150 ml max. Operating time was reduced by about 15 minutes. Although the number of cases is still small, this digital isolation technique can be considered safe, almost bloodless and should preserve erection in a higher percentage of patients compared to the “classic” nerve-sparing technique.

Cancer risk in the rubber industry: a review of the recent epidemiological evidence

OBJECTIVES

To examine the recent epidemiological evidence on cancer risk among workers in the rubber industry.

METHODS

Epidemiological studies published after the last detailed review by the International Agency for Research on Cancer (IARC) in 1982 were reviewed. 12 cohort studies in nine countries that examined distinct populations of workers in the rubber industry, seven industry based nested case-control studies, 48 community based case-control studies in 16 countries, and 23 studies based on administrative data that reported risks for employment in the rubber industry were identified.

RESULTS

Excess risks of bladder cancer, lung cancer, and leukaemia were found in most studies, with risks above 1.5 in about half of the studies. A moderate excess risk for laryngeal cancer was consistent across studies. Excess risks were found in a few studies for cancers of the oesophagus, stomach, colon, liver, pancreas, skin, prostate, kidney, brain, and thyroid, and for malignant lymphoma and multiple myeloma, but overall results were not consistent for these neoplasms.

CONCLUSIONS

Magnitude of the observed risks varied considerably between studies, but overall the findings indicate the presence of a widespread moderate increased cancer risk among rubber workers. The most consistent results were for bladder, laryngeal, and lung cancer and for leukaemia. Excess risks were also found for other neoplasms but an evaluation of the consistency of the findings is difficult because of the possible selective reporting of results. Recent studies do not provide information associating specific exposures with cancer risk. The preventive measures taken in the rubber industry in recent years may decrease risks, but this has not been documented yet in epidemiological studies.

Acute pancreatitis after long-term 5-aminosalicylic acid therapy

Acute pancreatitis is a known, although rare, complication of mesalamine treatment. This complication typically appears within the first days or weeks after initiation of therapy. We describe two cases of acute pancreatitis that occurred after long term mesalamine therapy for ulcerative colitis. A rechallenge, performed in both patients, confirmed the diagnosis of mesalamine-induced pancreatitis. These case reports provide evidence that 5-aminosalicylic acid may induce acute pancreatitis after long term treatment.

Impact of abomasal nematodes on roe deer and chamois body condition in an alpine environment

Abomasal helminths were examined from 101 roe deer and 43 chamois, shot or found-dead, in the period July-November 1993-95, in the Parco Naturale Paneveggio Pale di San Martino (Italian Eastern Alps). Twelve helminth species were observed in both roe deer and chamois. For both host species, discriminant analysis, using the abundance of each parasite species in the hosts, failed to distinguish between subjects from each of the three study years. For 44 roe deer and 27 chamois data on body weight, body length, foot length, withers height, thoracic circumference and kidney fat index were also available. Principal Component Analysis was performed on the biometrical data in order to group related variables into a few compound variables. In both host species it was possible to identify two principal components, with an explained variance > 80%: the first component, led by body length, was an expression of skeletal development and the second, led by kidney fat index, of nutritional status. Parasite abundance and richness appeared to be negatively correlated with the scores of both skeletal and nutritional Components in the two host species, although only the correlation between parasite abundance and the scores of the nutritional component in roe deer was statistically significant (Spearman r = -0.411; p < 0.05). These results support the susceptibility of roe deer to abomasal helminths, which could be important considering the spatial and nutritional interspecific competition between domestic and wild ruminants often recorded in alpine environments.

Effect of nedocromil sodium on bronchial hyperreactivity in children with nonatopic asthma

BACKGROUND AND OBJECTIVES

Although cromones inhibit immediate bronchial responses to both allergen and nonspecific challenge, their effectiveness in treating nonatopic childhood asthma is unknown. We therefore investigated a possible effect of nedocromil sodium on bronchial hyperreactivity and asthmatic symptoms in a group of children receiving this drug for nonatopic asthma.

STUDY DESIGN AND METHODS

A double-blind, placebo-controlled, randomized trial of two parallel groups was carried out in our pediatric respiratory disease clinic. Twenty children with mild, nonatopic asthma hyperreactive to fog-induced challenge were treated with inhaled nedocromil sodium 16 mg each day for 6 weeks (group N) or with a placebo (group P). Five girls and five boys (7 to 13 years of age) were randomly assigned to group N, and three girls and seven boys (aged 6 to 16 years) to group P. Symptoms and bronchodilator use were reported on diary cards. Ultrasonic nebulized distilled water PD10 was measured administering increasing doses of nebulized distilled water (2.5, 5, 10, 20, and 40 L).

RESULTS

Symptom scores were significantly affected by the active treatment. Baseline lung function was normal and remained unaltered after treatment with nedocromil sodium. Nonspecific reactivity was significantly reduced over time only in the active treatment group.

CONCLUSIONS

Nedocromil sodium can reduce the severity of asthmatic symptoms and nonspecific bronchial hyperreactivity at fog-induced challenge in children with stable, nonatopic asthma.

Polydeoxyribonucleotide (defibrotide) protects against post-ischemic behavioral, electroencephalographic and neuronal damage in the gerbil

The effectiveness of defibrotide, a single-stranded polydeoxyribonucleotide compound, in preventing damage caused by cerebral ischemia was studied. Global ischemia was induced in anesthetized gerbils by bilateral carotid artery occlusion for 10 min. Defibrotide (100 mg/kg) or saline was injected, i.v., immediately after reperfusion. The following parameters were evaluated simultaneously: (1) electroencephalographic (EEG) spectral power, recorded before, during and after the ischemic period; (2) body temperature, monitored with a rectal thermistor probe after reperfusion for 120 min; (3) spontaneous motility, evaluated through a photocell system and quantified in terms of total distance travelled in 30 min, 1 h after recirculation and at periods over 15 days; (4) mnemonic functions assessed by passive avoidance test from 3 to 15 days after ischemia; (5) histological examination, 7 days after reperfusion, counting CA1 hippocampal neuronal cells. The ischemia-induced complete flattening of spectral power was significantly reversed (P < 0.01) by post-ischemic treatment with defibrotide between 30 and 90 min after ischemia. A complete recovery of total EEG spectral power was seen in the defibrotide group at 6 h and the saline ischemic group at 1 day. Seven days after bilateral carotid occlusion, there was a significant decrease in spectral power (-70% +/- 6) together with a loss of the number of CA1 cells in the saline ischemic group (-64%). Treatment with defibrotide significantly protected against the decrease in spectral power (-30% +/- 7) and cell loss (-9%). Finally, the number of animals found to be protected against the ischemia-induced flattening was significantly larger for defibrotide-treated gerbils than for saline-treated animals throughout the experiment except for the third day. Body temperature was significantly decreased only at 30 min after reperfusion in both ischemic and sham-operated groups. Defibrotide reduced ischemia-induced hypermotility but only 6 h after the insult. The ischemia-induced impairment of memory was partially reversed within 3 days in the defibrotide-treated animals and fully reversed within 7 days in the defibrotide group and 15 days in the saline group. Our results demonstrate that defibrotide, even when administered after the post-ischemic period, possesses anti-ischemic properties. The mechanism by which defibrotide protects the ischemic reperfused brain is still largely unknown. However, a neuroprotection via adenosine A1 and A2 subtype receptor interaction can be put forward.

Ultrasonography-detected macroregenerative nodules in cirrhosis: a prospective study

BACKGROUND & AIMS

The preneoplastic role of macroregenerative nodules in cirrhosis is still debated. Thirty-two consecutive ultrasonography-detected macronodules were followed up to evaluate whether and which lesions are the actual precursors of hepatocellular carcinoma, if histology can identify preneoplastic macronodules, and whether additional parameters are related to neoplastic evolution.

METHODS

Macroregenerative nodule classification was based on recently proposed histological criteria. Extranodular liver cell dysplasia was also evaluated. The follow-up included ultrasonography and serum alpha-fetoprotein level determination every 3 months.

RESULTS

Twenty-two macronodules (78%) were classified as typical and 7 (22%) as atypical. Twenty-one were hypoechoic, and 11 were hyperechoic. Extranodular dysplasia was more frequently associated with atypical than typical macronodules (5 of 7 vs. 6 of 22). After 28 +/- 15 months, neoplastic transformation occurred in 8 macronodules (25%) and was more frequent in atypical than in typical (5 of 7 vs. 3 of 25), in hyperechoic than in hypoechoic (5 of 11 vs. 3 of 21), and in extranodular dysplasia-associated macronodules than in extranodular dysplasia-free macronodules (5 of 11 vs. 2 of 18). Five hepatocellular carcinomas appeared outside the original macronodule.

CONCLUSIONS

Atypical macroregenerative nodules can be considered precursors of hepatocellular carcinoma. Histology is useful in identifying preneoplastic macronodules, and hyperechoic pattern and extranodular dysplasia are additional risk factors for neoplastic transformation.

[Clinical response and survival in metastatic renal carcinoma during subcutaneous administration of interleukin-2 alone. Subcutaneous Il-2 in renal carcinoma]

Several clinical studies have demonstrated the efficacy of subcutaneous immunotherapy with Il-2 alone in metastatic renal cell carcinoma (RCC). In an attempt to better define the clinical parameters which may predict the efficacy of treatment, the present study shows the results obtained with subcutaneous Il-2 alone in 91 evaluable metastatic RCC patients. IL-2 was injected subcutaneously at 3 million IU twice/day for 5 days/week for 6 weeks, corresponding to one immunotherapeutic cycle. In nonprogressing patients, a second cycle was given after 28-day rest period. A complete response (CR) was achieved in 2/91 patients. Moreover, 19/91 patients had a partial response (PR). Therefore, objective response (OR) rate was 21/91 (23%) patients. Stable disease (SD) was achieved in 41 patients, while the remaining 29 patients had a progressive disease (PD). OR rate was significantly higher in patients with a long disease-free survival than in patients with synchronous metastases, in nephrectomized patients than in the non-nephrectomized ones, and in patients with high than in those with low PS. The survival obtained in patients with CR or PA was significantly longer with respect to that found in patients with SD or PD. The toxicity was substantially low in all patients. This study confirms that the subcutaneous immunotherapy with IL-2 alone is an effective and well tolerated therapy of metastatic RCC.

Extracorporeal lithotripsy in ureteral stones: Our experience with Dornier HM3, EDAP LT02, Piezolith 2300 lithotripters

We present our experience with three different lithotriptors: Dornier HM3, EDAP LT02 and Piezolith 2300. Materials and methods: 1876 patients with ureteral stones were treated between 1 January 1988 and 1 January 1996. The above 3 lithotriptors were used. In 925 patients the stones were located in the upper ureter, in 182 in the middle ureter and in 769 in the pelvic ureter. Auxiliary procedures were performed in 37% of patients. A DJ stent was used to catheterise 299 (16%) patients and a nephrostomy was performed in 19 (1%). Catheterisation was carried out in 247 (13.1%) ureters to localise the stones, plus 83 (4.4%) push ups and 52 (2.7%) Dormia baskets. Results: one treatment was sufficient in 1395 (74.3%) patients, 2 treatments in 335 (29.1%), 3 in 114 (6%), 4 in 21 (1.1%), 5 in 10 (0.5%) and 6 in 1 (0.05%). Patients were considered stone-free when they had negative X-ray and sonography two months after treatment; stones smaller than 3 mm, capable of being spontaneously eliminated without retrograde dilatation, were considered as fragments. The results were 1475 (78.6%) stone-free patients, 246 (13.1%) with fragments and 117 (6.2%) failures. 38 patients failed to appear at follow-up. Complications: complications were considered as hyperpyrexia and colics. There was very little hematuria, which regressed spontaneously in any case within the first 24 hours. Conclusion: side effects were few and required no treatment, so in our experience lithotripsy is the first choice treatment for ureteral stones. Particular attention, however, must be paid to the size of the stone in predicting the number of treatments.

Effects of nedocromil sodium on the oxidative burst of polymorphonuclear leukocytes: comparison with salbutamol

The effects of nedocromil sodium and of salbutamol on the generation of oxygen-derived free radicals in human polymorphonuclear leukocytes (PMNs) were compared in vitro by the luminol-amplified-chemiluminescence (LACL) assay induced by both particulate (Candida albicans) and soluble formyl-methionyl-leucyl-phenylalanine (fMLP) stimulants. Inhibitory dose-effect linear regressions were observed from 10(-3) to 10(-8) M for nedocromil and salbutamol after a 3' period of incubation with either C. albicans or fMLP. There was a linear regression with nedocromil sodium after 30' incubation, but desensitization was observed with salbutamol after this longer period of incubation. The generation of oxygen-derived free radicals was significantly greater for asthmatic patients than for normal subjects; therefore antiasthmatic drugs with this inhibitory activity could be an extra pharmacological benefit in the treatment of asthmatic patients.

Metabolism of hexachlorobenzene in humans: association between serum levels and urinary metabolites in a highly exposed population

Serum and urine from 100 subjects of a general population highly exposed to airborne hexachlorobenzene (HCB) were analyzed to obtain new insights into the metabolism of this ubiquitous compound. HCB was detected in all serum samples with concentrations ranging between 1.1 and 953 ng/ml. The major known metabolites of HCB were investigated in urine collected over 24 hr. Pentachlorophenol (PCP) was detected in all urines with values ranging between 0.58 and 13.9 micrograms excreted in 24 hr [mean +/- standard deviation (SD), 2.52 +/- 2.05; geometric mean, 2.05]. A sulfur derivative that, after hydrolysis, yielded pentachlorobenzenethiol (PCBT) could also be identified and quantified in all the urines with values ranging between 0.18 and 84.0 micrograms of PCBT excreted in 24 hr (mean +/- SD, 3.47 +/- 10.8; geometric mean, 1.39). The sulfur derivative assessed as PCBT appeared to be the main metabolite, with urinary concentrations surpassing those of PCP in the subjects with higher HCB accumulation (HCB in serum > 32 ng/ml). PCBT concentration in urine collected over 24 hr showed a very strong association with HCB concentration in serum; the association was stronger in males than in females. An increase of 1 ng/ml of HCB in serum led to an increase of 2.12 micrograms of PCBT excreted in urine collected over 24 hr in males (95% CI, 1.82-2.44) and to an increase of 0.67 microgram of PCBT in females (CI, 0.33-1.09). A weaker association was found between PCP in urine and HCB in serum, which was only statistically significant in males (an increase of 1 ng/ml of HCB in serum led to an increase of 0.63 microgram of PCP excreted in urine collected over 24 hr; (CI, 0.34-0.95). These results show that the formation of the cysteine conjugate is a quantitatively more important metabolic pathway in humans than the formation of PCP. Moreover, the association found suggests that PCBT is a good urinary marker of HCB internal dose and glutathione-mediated metabolism.

Naltrexone, naltrindole, and CTOP block cocaine-induced sensitization to seizures and death

I.c.v. injection for 9 days of either naltexone (NTX) (5, 10, 20, 40 micrograms/rat) or a selective mu peptide (CTOP) (0.125, 0.25, 0.5, 1, 3, 6 micrograms/rat) or delta (naltrindole) (NLT) (5, 10, 20 micrograms/rat) subtype opioid receptor antagonist affected sensitization to cocaine (COC) (50 mg/kg, i.p.) administered 10 min after. NTX (5 and 40 micrograms/rat), NLT (10 and 20 micrograms/rat), and the peptide CTOP (0.25-0.5 microgram/rat) attenuated seizure parameters (percent of animals showing seizures, mean score and latency) in a day-related manner. The DD50 (days to reach 50% of death) value for COC was 2.69, whereas it was 9.67 and 7.27 for NTX 5 and 40 micrograms/rat, 8.59 for NLT (10 micrograms/rat), and 6.11, 5.95, and 4.30 for CTOP (0.25, 0.5, and 1 microgram/rat respectively). These findings suggest a concurrent involvement of mu- and delta-opioid receptor subtype in COC-induced sensitization to toxic effects.

Ambiguous base pairing of the purine analogue 1-(2-deoxy-beta-D-ribofuranosyl)-imidazole-4-carboxamide during PCR

In principle the hydrogen bonding capacities of 1-(2-deoxy-beta-D-ribofuranosyl)-imidazole-4-carboxamide (dY), and its N-propyl derivative (dYPr), allow them to pair to all four deoxynucleosides. Their triphosphate derivatives (dYTP and dYPrTP) are preferentially incorporated as dATP analogues in a PCR reaction. However, once incorporated into a DNA template their ambiguous hydrogen bonding potential gave rise to misincorporation at frequencies of approximately 3 x 10(-2) per base per amplification. Most of the substitutions were transitions resulting from rotation about the carboxamide bond when part of the template. Between 11-15% of transversions were noted implying rotation of purine or imidazole moieties about the glycosidic bond. As part of a DNA template, dYPr behaved in the same way as dY, despite its propyl moiety. These deoxyimidazole derivatives are among the most radical departures from the canonical bases used so far as substrates in PCR and could be used to generate mutant gene libraries.

An inverted U-shaped curve for heptylphysostigmine on radial maze performance in rats: comparison with other cholinesterase inhibitors

The potential of heptylphysostigmine tartrate (pyrrolo [2,3b] indol-5-ol, 3,3a,8,8a-hexahydro-1,3a,8-trimethylheptylcarbamate [ester, (3aS-cis)]) (MF201), a new second-generation cholinesterase inhibitor, to antagonize scopolamine-induced amnesia in rats was assessed in an 8-arm radial maze. Upon completing the training session, the rats were orally administered increasing doses of MF201 (2, 3, 4, 6 and 8 mg/kg) 60 min prior to a s.c. injection of scopolamine (0.25 mg/kg). 9-Amino-1,2,3,4-tetrahydroamino-acridine hydrochloride hydrate (tacrine) (0.25, 0.37, 0.5, 1 and 2 mg/kg), 1-benzil-4-[(5,6-dimethoxy-1-indanon)-2-yl]-methyl piperidine (E2020) (0.125, 0.18, 0.25 and 0.5 mg/kg) and physostigmine (0.15, 0.25, 0.5 and 1 mg/kg) were orally administered and rats were tested in the same task. As previously described, scopolamine induced an impairment in radial maze performance, measured in terms of total number of errors, total time taken to complete the task and the percentage of amnesic animals. The reversal of scopolamine-induced impairment was characterized by the presence of an inverted U-shaped dose-response curve. A significant antagonistic effect was achieved with a dose (mg/kg) of 0.25 for E2020, 0.5 for tacrine and physostigmine and 3, 4 and 6 for MF201, the latter manifesting a broader spectrum of activity (3-6 mg/kg). While the maximal active doses restored the scopolamine-induced modified pattern of arm entry, they were ineffective in reducing hypermotility, suggesting the drugs have a specific effect on cognitive function.

Human immunodeficiency virus type 1 reverse transcriptase tG:T mispair formation on RNA and DNA templates with mismatched primers: a kinetic and thermodynamic study

The relationship between human immunodeficiency virus (HIV) type 1 reverse transcriptase tG:T mispair formation and base pair stability was investigated using DNA and RNA templates with 15 bp matched or mismatched DNA primers. tG:T mispair formation during primer elongation was undetectable on tDNA-DNA duplexes but occurred with a frequency of 10(-4) on matched tRNA-DNA duplexes. The frequency increased to 7.0 x 10(-4) and 1.3 x 10(-3) on tRNA-DNA duplexes with tG:T mismatches located 6 and 9 bp beyond the polymerization site. From Km values at 37 degrees C, the free energy change upon dissociation (delta G degrees 37) of the tG:T mispair increased from matched to mismatched tRNA-DNA duplexes by 0.36-1.21 kcal/mol. delta G degrees 37 for a correct tG:C pair decreased by 0.06-1.00 kcal/mol. In comparison with DNA-DNA duplexes, thermal melting measurements on RNA-DNA duplexes demonstrated smaller enthalpy (delta delta H degrees = -17.7 to -28.1 kcal/mol) and entropy (delta delta S degrees = -59.3 to -83.4 cal/mol/K) components. A strong entropy-enthalpy compensation resulted in small free energy differences (delta delta G degrees 37 = 0.8 to -2.2 kcal/mol). Thus, although DNA-DNA and RNA-DNA duplexes are of comparable stability in solution, the RNA-DNA duplex presents more facile base pair opening and higher conformational flexibility. The release of helical strain at constant helix stability in RNA-DNA duplexes may facilitate base mispairing during reverse transcription, particularly in the context of lentiviral G-->A hypermutation.

Interleukin-6 production by human liver (myo)fibroblasts in culture. Evidence for a regulatory role of LPS, IL-1 beta and TNF alpha

BACKGROUND/AIMS

Interleukin-6 is a major trigger for the synthesis of acute phase proteins by liver parenchymal cells. Acute phase proteins may contribute to the regulation of liver fibrosis by inhibition of proteases (e.g. collagenase) and by binding of cytokines. Since liver (myo)fibroblasts play an important role in the production of extracellular matrix in fibrotic livers, a study was undertaken into whether these cells are able to synthesize interleukin-6, which would give them the opportunity to contribute to regulation of synthesis of acute phase proteins by neighbouring parenchymal cells.

METHODS

In the present study we investigated interleukin-6 production by two cell types obtained from human liver tissue: human fat-storing cells obtained from 5-15% Percoll fractions, which transformed in culture into myofibroblasts co-expressing alpha-smooth muscle actin and vimentin (VA cells) and fibroblasts obtained from 30-40% Percoll fractions which express vimentin only (V vells). Interleukin-6 production was measured in culture media of these cells using an enzyme-linked immunosorbent assay after incubation with lipopolysaccharide, and mediators like interleukin-1 beta, tumor necrosis factor-alpha, transforming growth factor-beta and interferon-gamma, known to be present in elevated concentrations in fibrotic livers.

RESULTS

Unstimulated human liver (myo)fibroblasts produced considerable amounts of interleukin-6 (287 ng/mg cellular protein (VA cells), and 54 ng/mg cellular protein (V cells), within 48 h). Biological activity of these high concentrations of interleukin-6 measured in the enzyme-linked immuno-sorbent assay was confirmed in the B9-bioassay for interleukin-6 and by stimulation of alpha 2-macroglobulin production in rat liver parenchymal cell cultures. Lipopolysaccharide, interleukin-1 beta and tumor necrosis factor-alpha were potent stimulators of basal interleukin-6 production by VA and V cells, 1 microgram/ml lipopolysaccharide enhanced basal interleukin-6 production 3-fold within 48 h. 100 U/ml interleukin-1 beta and 1000 U/ml tumor necrosis factor-alpha each stimulated basal interleukin-6 production by VA cells 2-5 fold, whereas V cells were stimulated 10-25 fold. These effects were specific since the stimulation by lipopolysaccharide was completely inhibited by polymyxin B and the enhancing effects of interleukin-1 beta and tumor necrosis factor-alpha were neutralized by specific antibodies. Transforming growth factor-beta and interferon gamma did not influence interleukin-6 synthesis by either cell type in culture.

CONCLUSIONS

These results indicate that transformed fat-storing cells (VA cells) and fibroblasts (V cells) may function as a local source of interleukin-6 in the human liver. Since interleukin-6 plays a key role in the regulation of the production of acute phase proteins by liver parenchymal cells, we hypothesize that human liver (myo)fibroblasts may stimulate local production of acute phase proteins in the fibrotic liver, thus contributing to local regulation of inflammatory and fibrogenic reactions.

Collagen synthesis by human liver (myo)fibroblasts in culture: evidence for a regulatory role of IL-1 beta, IL-4, TGF beta and IFN gamma

BACKGROUND/AIMS

Different cytokines have been described in fibrotic livers, including interleukin-1, interleukin-4 and interferon gamma, which are capable of regulating collagen production in human skin and lung fibroblasts.

METHODS

To investigate possible involvement of interleukin-1, interleukin-4 and interferon gamma in the regulation of collagen production in human liver fibrosis, we studied the effects of these cytokines on collagen synthesis by nonparenchymal human liver cells in vitro. The effects of interleukin-1, interleukin-4 and interferon gamma were compared with the effect of transforming growth factor-beta, a well-known stimulator of collagen synthesis in liver fibrosis. Using a Percoll gradient we isolated two types of fibroblast-like cells from human liver tissue: fat-storing cells, which transformed in culture into myofibroblasts co-expressing vimentin and alpha-smooth muscle actin (VA-cells), and fibroblasts expressing vimentin only (V-cells). Production of collagen was measured in confluent cell cultures by incorporation of 3H-proline into collagenase degradable proteins.

RESULTS

The cytokines studied had comparable effects on collagen synthesis in confluent cultures of VA-cells obtained from three different human livers and in confluent cultures of V-cells. Interleukin-1 beta and interleukin-4 enhanced collagen synthesis dose-dependently. 100 U/ml interleukin-1 beta stimulated collagen synthesis up to 174 +/- 25% (mean +/- sd, VA-cells) and 140 +/- 7% (V-cells) of control values. 1000 U/ml interleukin-4 enhanced collagen formation up to 195 +/- 58% (mean +/- sd, VA-cells) and 153 +/- 4% (V-cells) of control values after 48 h. These values were comparable to the stimulatory effects induced by transforming growth factor-beta (235 +/- 33% (mean +/- sd, VA-cells) and 150 +/- 18% of control values (V-cells) after incubation with 10 ng/ml transforming growth factor-beta for 48 h). Interferon gamma reduced both basal (36 +/- 29% (mean +/- sd) of control values in VA-cells, and 59 +/- 9% in V-cells) and transforming growth factor-beta induced collagen synthesis.

CONCLUSIONS

These results indicate that in addition to the well-known role of transformed fat-storing cells (VA-cells) in collagen synthesis, fibroblasts (V-cells) may contribute to collagen production in human liver tissue. Moreover, these data demonstrate that in addition to the extensively documented collagen-inducing mediator transforming growth factor-beta, other cytokines present in fibrotic liver tissue like interleukin-1 beta and interleukin-4 may contribute to the enhanced synthesis of collagen, whereas interferon gamma may reduce collagen formation during liver fibrosis in man.

Reverse transcriptase and substrate dependence of the RNA hypermutagenesis reaction

G-->A hypermutation is a remarkable phenomenon resulting from retroviral reverse transcription in the presence of highly biased dNTP concentrations. Of the three reverse transcriptases (RTases) available, those of human immunodeficiency virus type 1 (HIV-1), avian myeloblastosis virus (AMV) and Moloney murine leukemia virus (MoMLV), the HIV-1 enzyme showed the greatest sensitivity to biased [dCTP]/[dTTP] ratios. The HIV-1 RTase was able to discriminate between dUTP, dITP and the four DNA precursors and was insensitive to pH. There was little preference for nucleotide contexts. A few exceptionally modified sequences were found presumably resulting from G-->A hypermutation and multiple strand transfer. This particular predilection of the HIV-1 and, by extrapolation, the lentiviral RTases towards G-->A hypermutation suggests that the phenomenon may have contributed to the remarkably elevated A content of these retroviral genomes.

EEG power spectra and behavioral correlates in rats given chronic morphine. Lack of residual long-term EEG and neuronal changes

The short-term (during tolerance to behavioural effects and withdrawal) and long-term (3, 6, 9 and 12 months after treatment) effects of morphine on mean total electroencephalographic spectral power (analysed by means of fast Fourier transform) and band distribution (delta, theta, alpha, beta) were studied in freely moving young rats implanted with chronic cortical bilateral recording electrodes. Morphine was administered i.p. daily for 1 month at weekly increasing doses of 20, 50, 100 and 200 mg kg-1, and the electroencephalogram was evaluated for 2 h at every change of dose. Treatment with 20, 50 and 100 mg kg-1 led to a significant increase in mean total spectral power 30-60 min from treatment. However, the dose of 100 mg kg-1 led to a smaller increase than that obtained with 50 mg kg-1 and no change was shown with the highest dose, suggesting the progressive development of tolerance. The modification observed for 100 mg kg-1 was accompanied by a relative increase in the delta and decrease in the theta and alpha power spectra. Between the last day of morphine and the first 3 days of abstinence, a progressive decrease in mean total spectral power accompanied by a significant increase in delta and beta and a decrease in theta and alpha frequency was observed. Long-term EEG activity and the counting of the pyramidal cells of the hippocampus failed to reveal any pathological findings after 3, 6, 9 and 12 months.

Behavioral and biochemical evidence of opioidergic involvement in cocaine sensitization

Chronic administration of cocaine produces sensitization to its behavioral effects in humans and experimental animals. In the present study, rats treated with cocaine (10 mg/kg, i.p.) once daily for 10 days showed an enhancement in the acute drug stimulation of locomotor activity and stereotypy. Biochemical analysis in the nucleus accumbens of chronic cocaine-treated animals indicated that sensitization of D1 dopamine (DA) receptors had also developed. In fact, stimulation of adenylyl cyclase activity by DA was increased in nucleus accumbens membranes from sensitized rats. Our findings suggest that a novel postsynaptic mechanism, i.e., an increased DA-D1 receptor function, may play a role in the sensitization. A causal relationship between the two events is supported by the observation that neither motor behavioral sensitization nor DA-dependent adenylyl cyclase hyperactivity developed when the opiate antagonist naltrexone (2 mg/kg, s.c.) was given daily for 10 days before cocaine. When given alone, naltrexone was inactive in all respects, which rules out any unspecific action and suggests that its effects may be due to competition at receptors with endogenous opioids mobilized by cocaine. This was indirectly supported by the finding that desensitization of opioid inhibition of adenylyl cyclase developed in nucleus accumbens membranes of cocaine-sensitized rats. Chronic blockade of opioid receptors by naltrexone also counteracted the reinforcing properties of cocaine; conditioned place preference, clearly displayed by cocaine-treated animals, was antagonized in a dose-related manner. Overall, these results confirm that endogenous opioid peptides play an important role in cocaine addiction.

Different kinetics of tolerance to behavioral and electroencephalographic effects of chlordiazepoxide in the rat

The daily oral administration of chlordiazepoxide (40 mg/kg) over 9 weeks in rats elicited full tolerance to muscle relaxant effects within 7 weeks, as revealed by twice weekly evaluations of abdominal tone myorelaxation and decreased grip strength. No full tolerance was achieved, however, during the 9 weeks of treatment in terms of ataxia. Electroencephalographic (EEG) studies showed that this tolerance to the behavioural effects was accompanied by a progressive decrease in mean power spectra, associated with a progressive decrease in the beta band, but in this case, full tolerance was reached within 4 weeks. Once weekly evaluations of the ability of chlordiazepoxide to protect the animals against pentylenetetrazole seizures revealed a similar pattern. Treatment with flumazenil (50 mg/kg p.o.) 24 h after the last chlordiazepoxide administration induced a clear withdrawal syndrome associated with EEG changes which consisted of an increase in total power spectra associated with an increase in the delta band (in comparison with chlordiazepoxide-dependent rats not given the antagonist). These findings suggest that the different kinetics of the tolerance to anticonvulsant and EEG effects in comparison to myorelaxant effects can be attributed to a different involvement of benzodiazepine receptor subtypes.

Relationship between morphine and etonitazene-induced working memory impairment and analgesia

An 8-arm radial maze task was used to assess the possible role of the opiate system in the spatial memory of the rat. Increasing doses of etonitazene (0.005-0.06 mg/kg i.p.) and morphine (2.5-100 mg/kg i.p.) significantly impaired performance in the working memory components of the task. For both drugs this impairment was linearly related to the log of the administered dose, and the log-dose relationships were parallel. The regression lines calculated for each parameter for both drugs were parallel thus allowing us to calculate the potency: etonitazene proved to about 1000 times more potent than morphine in terms of correct arm entries, the number of errors and the total time taken to complete the task. Moreover, the progressive cognitive impairment produced by both opiates was closely related to an increase in analgesic effect. Pretreatment with naloxone (5 mg/kg i.p.) completely antagonised the disruptive effect of the opiates on working memory. The importance of the mu subtype opiate receptor in cognitive processes is discussed.

Chronic morphine affects working memory during treatment and withdrawal in rats: possible residual long-term impairment

An eight-arm radial maze was used to investigate a possible short-term (during the development of tolerance and dependence) and long-term (6, 9 and 12 months after treatment) effect on working memory, in young rats, which drank morphine (0.5mg/ml) for 1 month, or to which the drug was administered by i.p. injection (at weekly increasing doses of 20, 50, 100, 200mg/kg). Tail flick test and cortically derived electroencephalographic (EEG) recordings were also carried out in the same rats to determine any modifications in analgesia and in total EEG mean power spectra during treatment and withdrawal. Complete tolerance to morphine analgesia developed during the period of drug treatment. Chronic morphine significantly impaired radial maze performance in the working memory components of the task during both treatment and early withdrawal, but only in the i.p. group. Six and 9 months after morphine treatment, both the oral and i.p. group showed a significant impairment of radial maze performance. The mean power spectra were altered during treatment but returned to baseline values during abstinence, except for the first day. These findings suggest the possibility of morphine-induced premature ageing, which is more evident in i.p. treated animals. The mechanism by which morphine treatment produces residual long-term learning impairment requires further elucidation.

Compliance with pharmacologic prophylaxis and therapy in bronchial asthma

Between January 1 and December 31, 1988, 288 children [185 boys and 103 girls, mean age 8.75 +/- 4.98 years (range 2.50 to 16.83)], followed at the Outpatient Clinic for Lung Diseases of the University of Milan 5th Pediatric Department, were interviewed blindly in order to assess their compliance with pharmacologic therapy. All children were suffering from episodic, frequent, or chronic asthma requiring therapy as needed and preventive drugs for at least 30 days. Prophylaxis (including cromolyn, beclomethasone, theophylline retard, ketotifen, oxatomide, albuterol, and prednisone, alone or in combinations) and therapy in case of symptoms (albuterol, with or without theophylline prompt or beclomethasone) were prescribed. A study questionnaire was completed 30 to 45 days after the prescription with no advance warning by a physician unaware of the prophylactic and therapeutic prescriptions. Out of the 288 patients, 31 (10.8%) failed to return for the second visit. Understanding of prophylaxis was full in 61.1% of cases, partial in 23.3% and nil in 4.9%. Therapy as needed was fully remembered by 77.1% of parents, partially by 9.4% and totally forgotten by 2.8%. Compliance with single-drug prophylaxis was full in 60.1% of cases, partial in 22.2% and nil in 6.4%. Statistical analysis showed compliance was significantly better for ketotifen than for disodium cromoglycate (chi squared 9.85, P < .02), for ketotifen than for theophylline (chi squared 9.98, P < .02), and for beclomethasone than for theophylline (chi squared 8.77, P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Spatial discontinuities in human immunodeficiency virus type 1 quasispecies derived from epidermal Langerhans cells of a patient with AIDS and evidence for double infection

A nonhomogeneous spatial distribution of human immunodeficiency virus type 1 quasispecies was observed for epidermal Langerhans cells purified from skin patches taken from a patient with AIDS soon after death. Each patch presented a unique collection of sequences, distinct from those of juxtaposed patches or those derived from the other leg. Infection of Langerhans cells by virus from underlying T cells in the dermis might explain this partition. The analysis revealed the presence of two distinct cocirculating viral strains, indicating double infection.

G-->A hypermutation of the human immunodeficiency virus type 1 genome: evidence for dCTP pool imbalance during reverse transcription

The quasispecies model for RNA viruses predicts the existence of a replication error threshold beyond which there is a melting or total loss of sequence information. Retroviral G-->A hypermutation is probably an example. Here it is shown that G-->A transitions may occur in both GpG and GpA dinucleotide contexts. Transitions in GpG preferentially occur via base mispairing at the ends of runs of G residues, whereas G-->A transitions within GpA may result from temporary dislocation of the primer and template strands by a single base. The two circumstances may be related by the local dCTP substrate concentration. An in vitro elongation assay shows that primer/template dislocation is more frequent for the human immunodeficiency virus type 1 reverse transcriptase than for murine or avian retroviral enzymes. Taken together these data suggest that G-->A hypermutation is an example of induced mutation whereby the viral reverse transcriptase is forced into making errors by imbalances in the intracellular dCTP concentration.

[Andrological complications after pancystoprostatovesiculectomy surgery: utility of the bulbocavernosus reflex]

The technique for radical cystoprostatectomy was modified to avoid injury to the branches of pelvic plexus that innervate the corpora cavernosa (monolateral neurovascular bundle preservation or "Nerve sparing technique"). The studies of Walsh and coll. demonstrated that the branches of pelvic plexus that innervate the corpora cavernosa are situated between the rectum and urethra and penetrate the urogenital diaphragm near to the muscular wall of the urethra. Injuries to the pelvic plexus can occur during 1) division of posterior pedicle of bladder (the seminal vesicle can be used as a landmark intraoperatively to avoid injury to pelvic plexus), 2) during apical dissection of prostate with transection of the urethra. The return of sexual function postoperatively is related to preservation of autonomic innervation; the excision of the neurovascular bundle on one side may prevent impotence in 68% patients. Our study was undertaken to identify the cause of impotence in men undergoing radical cystoprostatectomy with "Nerve sparing technique" using bulbo cavernous reflex. Our results suggest that bulbo cavernosus reflex may not be a sensitive clinical tool to establish a diagnosis of neurogenic erectile dysfunction after pelvic surgery. The Authors examine the recent neuro-uro-physiological diagnostic methods for the study of neurogenic erectile dysfunction.