Primary carcinoid tumor of kidney: Light and electron microscopy, and immunohistochemical study

We present a case of primary renal carcinoid tumor with the appearance of type B carcinoid with trabecular and ribbon-like structure. All the immunohistochemical stains were negative. Electron microscopy revealed numerous cytoplasmic granules with polar distribution and masses of intermediate microfilaments. We believe only 8 cases have been reported in the literature.     

Patients on renal replacement therapy for 20 or more years: a clinical profile.

BACKGROUND: Long-term survivors are living evidence of the goals and limits of renal replacement therapy (RRT). METHODS: A cross-sectional study was performed on all cases (188 patients) with RRT follow-up >/=20 years in Piemonte, northern Italy (4 350 000 inhabitants, 22 dialysis centres). Study included revision of clinical charts and assessment of functional (Karnofsky scale, Ks) and nutritional status (subjective global assessment, SGA). According to treatment history, patients were sorted into three groups: group 1, 56 patients always on dialysis; group 2, 40 patients on dialysis with previous graft; group 3, 92 grafted patients. RESULTS: Age differed between group 1 and groups 2 and 3 (59.5+/-11.5 vs 51.5+/-7.9 and 51.0+/-9.0 years; P=0.001). Prevalence of comorbidity was higher in groups 1 and 2 (94.6% and 95%) compared with group 3 (81.5%), reflecting selection during follow-up. Twenty-two cases (11.7%) had no comorbidity; these patients were younger (44.3+/-8.5 years) and 17 out of 22 had a functioning graft. The most common comorbidities were vasculopathy (73.4%), bone disease (72.9%) and cardiopathy (33.5%). Severe visual impairment was a common problem (18%), with a higher prevalence in patients with cardiovascular comorbidity (32%). Severe depression was found in 13.3% of cases. Despite comorbidity, functional scores (Ks) were good (higher in group 3 (88.1+/-15) than in groups 1 and 2 (67.9+/-21.9 and 75.5+/-18, respectively); P=0.000) and 64% of patients were well nourished. The combination of cardiovascular comorbidity, bone disease and visual impairment may reflect the premature ageing of RRT patients. CONCLUSION: Despite the high prevalence of comorbidity, long-term follow-up may promote good clinical conditions at least in some patients, highlighting the therapeutic potentials of dialysis in an era of reconsideration of open acceptance of RRT.     

Isolated femoral mononeuropathy to the vastus lateralis: EMG and MRI findings

A 16-year-old female track athlete experienced sudden onset of right anterolateral thigh pain, initially thought to be cramping. After 2 months of continued postexercise pain she sought medical evalution. A 3-cm thigh circumference discrepancy was noted on physical exam. She was referred for electromyography (EMG) and magnetic resonance imaging (MRI) studies. Femoral and screening nerve conduction studies were normal. Needle EMG revealed acute neuropathic changes confined to the right vastus lateralis only. These findings were confirmed by MRI, including short T₁ inversion recovery (STIR) sequences. All other medical work-up was normal, including lumber and pelvic MRI, and complete serologic studies. This case represents a unique presentation of an idiopathic femoral mononeuropathy isolated to the vastus lateralis only, which has not been previously reported. The highly unusual anatomical presentation of this case illustrates the emerging complementary usefulness of EMG and MRI in delineating neuromuscular pathology.© 1995 John Wiley &Sons, Inc.     

Gas chromatography-mass spectrometry determination of ethylenethiourea hemoglobin adducts: a possible indicator of exposure to ethylene bis dithiocarbamate pesticides

 Ethylenebisdithiocarbamates (EBDC) are an important class of fungicides used to control crop diseases and prevent mold. Ethylenethiourea (ETU), reported to be their main degradation and metabolic product in animals and man, may have teratogenic and carcinogenic properties. The feasibility of monitoring exposure to ETU on the basis of the formation of adducts to hemoglobin (Hb) was investigated. Rats given a single oral dose of ETU (from 62.5 to 500 mg/kg body wt) formed stable covalent ETU-Hb adducts. Mild acid hydrolysis of the protein regenerated ETU, allowing its detection by isotope dilution gas chromatography-mass spectrometry (GC-MS). The amount of released ETU increased with the dose. The dose-response curve fitted a linear model only between 62.5 mg/kg and 250 mg/kg. Acid-releasable ETU was also positively identified in the hemoglobin of workers exposed to Mancozeb, an EBDC formulation. In the exposed group, 40% had ETU-Hb adducts levels ranging from 0.5 to 1.42 pmol ETU/mg Hb. Such adducts might be useful for measuring EBDC exposure in humans. Received: 18 July 1994/Accepted: 19 October 1994     

Pharmacokinetic profile and metabolism of N-nitrosobutyl-(4-hydroxybutyl)amine in rats

N-Nitrosodibutylamine and its omega-hydroxylated metabolite N-nitrosobutyl(4-hydroxybutyl)amine (NB4HBA) induce tumors in the urine bladder of different animal species through their common urinary metabolite N-nitrosobutyl(3-carboxypropyl)amine (NB3CPA), resulting from the oxidation of the alcoholic group of NB4HBA to a carboxylic group. NB4HBA disappearance from blood, the formation of its main metabolites, NB3CPA and NB4HBA-glucuronide (NB4HBA-G), and their urinary excretion, were investigated in rats after an i.v. dose of 1 mg/kg (5.7 mumol/kg). NB3CPA and NB4HBA-G formation was readily detectable 2 min after treatment and levels were still measurable at 120 and 30 min, respectively. The parent compound disappeared from blood 90 min after injection. The NB4HBA blood concentration-time profile was adequately described by a one-compartmental linear model. NB4HBA half-life was 8 min, total body clearance and renal clearance were 86.1 and 0.22 ml/min/kg, respectively. The 0-96-h urinary excretion of NB4HBA was 0.3% of the administered dose. NB3CPA half-life was 15 min; NB3CPA and NB4HBA-G urinary excretion were 36 and 11.7%, respectively, urinary excretion of known compounds accounting for less than 50%. After i.v. injection of NB3CPA equimolar to the NB4HBA dose, only 50% of unchanged compound was recovered in the urine and after NB4HBA-G, 41% of the administered dose was excreted unchanged, NB3CPA accounting for 10%. Thus NB3CPA and NB4HBA-G might undergo further biotransformation, suggesting that NB3CPA may not be the ultimate carcinogen responsible for urinary bladder tumor induction.     

Septal lesions and avoidance behavior: Genetic,neurochemical and behavioral considerations

Previous research found that the effects of septal lesions on active and passive avoidance behavior were dramatically determined by the genotype of the mouse employed. We present here a series of experiments which attempted to described how septal lesions affect these lines as reflected in behaviors known to be sensitive to such brain damage and how such changes might relate to those seen in avoidance behavior. We examined turnover rates and levels of catecholamines and changes in sensory/motor reactivity in a series of 5 experiments. Although many of our measures were markedly altered by interactions between genotype and lesion, a simple predictive relationship between such changes and avoidance behavior was not observed. Our results emphasize the critical need to establish extensive behavioral “profiles” which take into account task and genotypic considerations in the analysis and interpretation of the impact which brain damage has on behavior.     

Does speed of intrathecal injection affect the distribution of 0.5% hyperbaric bupivacaine?

We have evaluated the influence of speed of intrathecal injection on lateral distribution of 0.5% hyperbaric bupivacaine. We studied 60 patients undergoing lower limb surgery who were placed in the lateral position with the operative side in the dependent position. After dural puncture (25-gauge Whitacre spinal needle), the needle aperture was turned towards the dependent side and 0.5% hyperbaric bupivacaine 8 mg was injected randomly at a rate of 0.02 ml s-1 (group slow, n = 30) or 0.25 ml s-1 (group fast, n = 30). Lateral position was maintained for 15 min while a blinded observer recorded loss of pinprick sensation and degree of motor block on both surgical and non-surgical sides. There were no differences between the groups. Forty-five minutes after patients were turned to the supine position, spinal anaesthesia was unilateral in 17 patients in group slow (56%) and in 13 patients in group fast (43%). We conclude that using extremely low speeds for intrathecal injection were not clinically advantageous in obtaining unilateral spinal anaesthesia.      

Effect of amphetamine and cocaine on seizure in lead treated mice

Mice, genetically selected for differences in brain weight were employed. Lead administration (0.5% lead acetate) from conception increased the proportion of 21 day old mice exhibiting seizures; total duration of observed seizures was also increased. Mice from the low brain weight line more frequently exhibited seizures than either mice from the high brain weight line or the Binghamton heterogeneous stock. Although genome and lead administration after bodyweight, the inability of bodyweight to predict seizure occurrence and/or total duration of seizure within conditions also was noted. Lead administration from conception through testing increased the probability and duration of transcorneally induced electroconvulsive seizures of 21 day old mice within all three genotypes, and both cocaine and amphetamine injections 15 min prior to ECS reduced the number of animals exhibiting seizures as well as the duration of seizures in both lead treated and control mice.