Long term effects of lipopolysaccharide on satellite glial cells in mouse dorsal root ganglia.

Lipopolysaccharide (LPS) has been used extensively to study neuroinflammation, but usually its effects were examined acutely (24h<). We have shown previously that a single intraperitoneal LPS injection activated satellite glial cells (SGCs) in mouse dorsal root ganglia (DRG) and altered several functional parameters in these cells for at least one week. Here we asked whether the LPS effects would persist for 1 month. We injected mice with a single LPS dose and tested pain behavior, assessed SGCs activation in DRG using glial fibrillary acidic protein (GFAP) immunostaining, and injected a fluorescent dye intracellularly to study intercellular coupling. Electron microscopy was used to quantitate changes in gap junctions. We found that at 30 days post-LPS the threshold to mechanical stimulation was lower than in controls. GFAP expression, as well as the magnitude of dye coupling among SGCs were greater than in controls. Electron microscopy analysis supported these results, showing a greater number of gap junctions and an abnormal growth of SGC processes. These changes were significant, but less prominent than at 7 days post-LPS. We conclude that a single LPS injection exerts long-term behavioral and cellular changes. The results are consistent with the idea that SGC activation contributes to hyperalgesia.

Necessity of therapy for post-thyroidectomy hypocalcaemia: a multi-centre experience.

PURPOSE: Hypoparathyroidism is one of the most common and most feared complications of total thyroidectomy (TT). The aim of this study is to detect possible markers that may facilitate early tracing of hypocalcaemia-prone patients in order to reduce clinical cost by optimizing patient discharge and to avoid unnecessary treatment. METHODS: Over an 18-month period, 995 patients, 23 % male and 77 % female, aged 52.9 ± 13.4 years, underwent TT in ten Lombardy hospitals. The following parameters were analyzed: calcaemia before and 12-24 and 48 h after surgery, pre- and post-operative parathyroid hormone (PTH) at 24 h and pre-operative 25OH vitamin D. RESULTS: Mortality was nil and morbidity was 22.4 %. Mean 24-h calcaemia and PTH were 2.17 ± 0.15 mmol/l and 31.81 ± 20.35 pg/ml, respectively; mean 24-h PTH decay was 36.7 ± 34.12 %. Four hundred seventy-three (47.5 %) patients were hypocalcaemic at discharge; 142 of whom had transient hypoparathyroidism that became permanent in 27. Patients developing hypocalcaemia had significantly higher values of PTH and calcium decay. At multiple logistic regression, only 24-h calcium decay, PTH drop and the presence of symptoms and parathyroid auto-grafting were significantly related to hypoparathyroidism. The association of these factors had a 99.2 % negative predictive value (NPV) for the development of hypoparathyroidism. A 70 % PTH drop had a 93.75 NPV for transient hypoparathyroidism. A 12 % calcaemia decay had a 95.7 NPV for hypoparathyroidism. CONCLUSIONS: Hypocalcaemic asymptomatic patients with less than 70 % PTH and 12 % calcaemia decay may be safely discharged without treatment. Symptomatic patients and those with parathyroid grafting should receive calcium and vitamin D.

Motor regulation results in distal forces that bend partially disintegrated Chlamydomonas axonemes into circular arcs.

The bending of cilia and flagella is driven by forces generated by dynein motor proteins. These forces slide adjacent microtubule doublets within the axoneme, the motile cytoskeletal structure. To create regular, oscillatory beating patterns, the activities of the axonemal dyneins must be coordinated both spatially and temporally. It is thought that coordination is mediated by stresses or strains, which build up within the moving axoneme, and somehow regulate dynein activity. During experimentation with axonemes subjected to mild proteolysis, we observed pairs of doublets associating with each other and forming bends with almost constant curvature. By modeling the statics of a pair of filaments, we show that the activity of the motors concentrates at the distal tips of the doublets. Furthermore, we show that this distribution of motor activity accords with models in which curvature, or curvature-induced normal forces, regulates the activity of the motors. These observations, together with our theoretical analysis, provide evidence that dynein activity can be regulated by curvature or normal forces, which may, therefore, play a role in coordinating the beating of cilia and flagella.

The perineuronal glial tissue of spinal ganglia. Quantitative changes in the rabbit from youth to extremely advanced age.

The volumes of the nerve cell bodies and those of the enveloping satellite cell sheaths from spinal ganglia were determined by morphometric methods applied to electron micrographs in young, adult, old and very old rabbits. The mean volume of the nerve cell bodies increased progressively with age; this is probably related to the increase with age of the body size of the rabbits studied. The mean volume of the satellite cell sheaths did not differ significantly in young, adult and old animals, but was significantly smaller in very old animals. It is extremely unlikely that this marked reduction in the volume of the satellite cell sheath is the result of a pathological process. The mean value of the volume ratio between the satellite cell sheaths and the related nerve cell bodies did not differ significantly in young and adult animals, but was significantly smaller in old and very old animals. This ratio was particularly low in very old animals. Our analysis showed that in each age group the volume of the satellite cell sheath is linearly related to the volume of the related nerve cell body. This result suggests that in rabbit spinal ganglia the quantitative relations between glial and nervous tissue are tightly controlled throughout life. It is suggested that ganglionic neurons release signals to influence and control the volume of their associated glial tissue. Since satellite cells have important support roles for the neurons they surround, it is likely that the marked reduction in the volume of perineuronal sheaths in the extremely advanced age is accompanied by a reduction of those roles, with negative consequences for neuronal activity.

A study of mitochondria in spinal ganglion neurons during life: quantitative changes from youth to extremely advanced age.

In view of the central role that mitochondria are thought to play in the ageing process, we investigated changes in mitochondria of spinal ganglion neurons in rabbits aged 1, 3.6, 6.7, and 8.8 years (the latter extremely old). Mitochondrial size increased significantly with age, while mitochondrial structure did not change. The total volume of mitochondria within the perikaryon did not change significantly during life. This indicates that in these neurons mitochondrial degradation was completely compensated by the production of new mitochondria even in the extremely advanced age. We also found that the mean volume of neuronal perikaryon increased markedly with age, so that the mean percentage of perikaryal volume occupied by mitochondria decreased significantly with a difference of about 33% between the youngest and the oldest animals. This decrease is only in very small part due to lipofuscin accumulation, so that the ratio of the total volume of mitochondria to the volume of functionally active cytoplasm decreased with age. The mitochondria of the neurons studied seem therefore unable to adapt their total volume to the volume of functionally active cytoplasm, that increases with age. This result is consistent with the observation that the neurons of old animals have a reduced ability to respond to high energy demands.

Seasonal variation of aryl hydrocarbon hydroxylase activity in human lymphocytes.

A seasonal variation was observed when aryl hydrocarbon hydroxylase (AHH) activity was measured in the cultured lymphocytes of 977 donors over a period of 2 1/2 years. The variation was strongest in AHH activity induced by 3-methylcholanthrene and was less apparent for AHH activity in lymphocytes grown without any inducer. The period of the seasonal variation is 1 year, and maximal induced AHH activity occurs during late summer and early fall with minimal activity 6 months later. Based on the average of all individuals tested during the highest and lowest weeks, induced AHH activity can be as much as 10-fold higher during the peak season. It is not possible to tell from these experiments whether the seasonal variation is tissue specific, occurring only in lymphocytes, or characteristic of microsomal oxidases in other tissues as well.

Increase in number of the gap junctions between satellite neuroglial cells during lifetime: an ultrastructural study in rabbit spinal ganglia from youth to extremely advanced age.

This study investigated quantitative aspects of the gap junctions between satellite neuroglial cells that envelope the spinal ganglion neurons in rabbits aged 1 year (young), 3.6 years (adult), 6.7 years (old), and 8.8 years (very old). Both the total number of gap junctions present in 30,000 microm2 of surface area occupied by perineuronal satellite cells, and the density of these junctions increased throughout life, including the extremely advanced age. By contrast, the mean length of individual gap junctions did not change with age. Thus, the junctional system which provides morphological support for the metabolic cooperation between satellite cells in rabbit spinal ganglia becomes more extensive as the age of the animal increases. These results support the hypothesis that the gap junctions between perineuronal satellite cells are involved in the spatial buffering of extracellular K+ and in neuroprotection.

Active site titration of bovine beta-trypsin by N alpha-(N,N-dimethylcarbamoyl)-alpha-aza-lysine p-nitrophenyl ester: kinetic and crystallographic analysis.

Kinetics of bovine beta-trypsin (trypsin) with the N alpha-(N,N-dimethylcarbamoyl)-alpha-aza-lysine p-nitrophenyl ester (Dmc-azaLys-ONp) was obtained at pH 6.2 and 21.0 degrees C. Dmc-azaLys-ONp shows the characteristics of an optimal active site titrant in that it (i) gives titrations in a short time, (ii) is a stable and soluble compound with a stoichiometric reaction that is easily and directly detectable, and (iii) allows titrations over a wide range of enzyme concentration. Moreover, the three-dimensional structure of the trypsin.N alpha-(N,N-dimet hylcarbamoyl)-alpha-aza-lysine acyl.enzyme adduct has been solved by X-ray crystallography at 2.0 A resolution (R = 0.145). The Dmc-azaLys moiety of the active site titrant is sited in the serine proteinase reaction center, and is covalently linked to the OG atom of the Ser195 catalytic residue.

Comparison of benzo[a]pyrene metabolism by human peripheral blood lymphocytes and monocytes.

Here we report a more sensitive high-pressure liquid chromatographic (HPLC) assay of benzo[a]pyrene (BP) metabolites elaborated by human monocytes and lymphocytes using only 10 X 10(6) cells for HPLC analysis. The major metabolites formed by both lymphocytes and monocytes were 3-hydroxy-BP, 9-hydroxy-BP and quinones. BP-dihydrodiols were also found by HPLC analysis, the major one being BP-7,8-dihydrodiol for both cell types. In addition, a peak slightly more polar than 9,10-dihydrodiol was formed by lymphocytes. The 7,8-diol peak was eliminated by the addition of 1,1,1-trichloropropene oxide to the incubation mixture. The presence of alpha-napthoflavone resulted in an overall decrease in metabolite production.

Age-related decrease in the overall extent of perikaryal projections in rabbit spinal ganglion neurons.

The overall extent of the perikaryal projections of sensory neurons from spinal ganglia of young adult and aged rabbits was estimated by a stereological method using the electron microscope. The extent of perikaryal projections was significantly smaller in the aged animals. This age-related decrease did not seem to depend on factors intrinsic to the neuron, but on the absence of a satellite cell covering over extensive portions of the nerve cell body surface. This decrease may influence the organization of the subplasmalemmal cytoskeleton, metabolic exchange between the nerve cell body and its environment and perhaps also neuronal metabolism.

Age-related quantitative changes in mitochondria of satellite cell sheaths enveloping spinal ganglion neurons in the rabbit.

We studied mitochondria in the satellite cell sheaths which envelope the spinal ganglion neurons of rabbits aged 12, 42, and 79 months. While the mean cytoplasmic volume of satellite cell sheaths did not change significantly with age, the mean percentage of cytoplasmic volume occupied by mitochondria decreased with age. This decrease is mainly due to a reduction in the total mitochondrial mass and only in minor part is a consequence of lipofuscin accumulation. Mitochondrial structure did not change, while mitochondrial size increased with age. Comparison between mitochondria in nerve cell bodies and those in satellite cell sheaths showed that: (1) the mean percentage of cytoplasmic volume occupied by mitochondria was greater in nerve cell bodies than satellite cell sheaths and the ratio between these two percentages remained constant with advancing age; (2) the total mitochondrial mass was much greater in nerve cell bodies than satellite cell sheaths and the ratio between these two values increased with age; (3) the extent of increase of mitochondrial size with age was similar in nerve cell bodies and satellite cell sheaths. The results of the present study suggest that: (1) the ability of satellite cell sheaths to produce energy decreases with age; (2) the decreased ability of sensory neurons in old animals to meet high energy demands may be partly due to the diminished contribution of their associated satellite cell sheaths.

Prevalence of Dirofilaria immitis in a stray dog population in western New York.

In a survey in 1973 undertaken to determine the prevalence of Dirofilaria immitis in 100 dogs from a public pound in western New York, 2 dogs were found to be positive. Microfilariae of Dipetalonema sp were not present. Hearts and pulmonary blood vessels were dissected for adult worms, and blood samples were examined for microfilariae, using a modified Knott technique. Although adult heartworms and microfilariae have been recovered from wild foxes, coyotes, and wolves in New York, this is the first report of heartworm in domesticated dogs in the state.

Gap junctions between perineuronal satellite cells increase in number with age in rabbit spinal ganglia.

The gap junctions between perineuronal satellite cells were studied in the spinal ganglia of 12, 42, and 79-month-old rabbits. The mean number of gap junctions per 100 microm2 of surface of the section occupied by satellite cells was significantly greater in old rabbits than young adults. Since the mean length of individual gap junctions did not change with age, the increase in number of gap junctions cannot be due to fragmentation of pre-existing gap junctions but is very likely due to the formation of new gap junctions. The increase in number of gap junctions cannot be related to an increase in number of perineuronal satellite cells since the mean number of these cells is significantly smaller in aged rabbits than in young adults. It is suggested that the increase in number of gap junctions with age may enhance the suggested neuroprotective role of satellite cells towards ganglionic neurons. The present findings, together with previous observations, suggest that the gap junctions between perineuronal satellite cells are dynamic structures, able to adapt to varying neuronal demands and varying environmental conditions.

Gastrointestinal carcinoids. Prognosis and survival.

BACKGROUND: Gastrointestinal carcinoid tumors are rare and little is known about factors related to prognosis in patients with carcinoid disease. Aim of this study is to determine the impact of clinical presentation variables on the management and survival. METHODS: We have evaluated 31 consecutive patients with gastrointestinal carcinoid tu-mours who underwent surgical intervention at the I Department of Surgery of Milano-Bicocca University over 15 years (1985-1999). Tumor distribution, hormone production, prognostic factors and survival were analysed. RESULTS: Carcinoid syndrome was the only clinical pattern diagnostic of carcinoid tumour. Most common symptoms were abdominal pain (64%), nausea and vomiting (48%). High levels of urinary 5-hydroxyindolacetic acid were significantly associated with carcinoid syndrome and metastatic disease. Tumor size, depth and gender were significant predictors of metastases. Age, gender, tumor size, metastatic spread and location were statistically significant predictors of death. CONCLUSIONS: Clinical presentation was non specific except for those patients affected by carcinoid syndrome. Ten years overall survival was 43%, with 52% metastatic spread incidence. The extent of surgical resection should be modulated on patient related risk factors. Poor prognostic factors affecting survival were: age, gender, metastatic disease, depth of invasion and tumour size.

[Stomach lymphoma]. / Linfoma a localizzazione gastrica.

BACKGROUND: Primitive gastric lymphoma (PGL) is a rare tumour, and although its incidence is rising it is difficult to state the role of the various therapeutic methods in treating this disease. Aim of this study is to point out what sequence of treatment is more effective trying to find out some guidelines which can be useful in clinical practice. METHODS: Retrospective analysis of clinical data of 54 patients with PGL admitted at a University surgical department during 10 years. All the patients underwent neoadjuvant or adjuvant chemotherapy and D2 gastrectomy. Follow-up ranged from 6 to 120 months. Survival was related to: Mushoff's stage of disease, the grade according to the Working Formulation and the sequence of treatment. Statistical analysis was performed by Kaplan-Maier method and the difference between survival curves was compared by log-rank test. RESULTS: Mean postoperative hospital stay was 12 days and morbidity was 18%. Five and 10 years overall survival rates were 70 and 85%. There was a significant difference in survival between patients with high grade PGL and those with intermediate grade (p=0.0188) as well as in those with low grade (p=0.0435). Patients in stages IE-II1E had a significantly longer survival than those in stages IIIE-IVE (p=0.0123). Patients in stages IE-II1E underwent neadjuvant chemotherapy and surgery and survived longer than those in whom surgery preceded chemotherapy (p=0.0293) instead for patients in stages IIIE-IVE neoadjuvant chemotherapy shortened survival (p=0.0403). CONCLUSIONS: In personal opinion, in patients in stages IE-II1E chemotherapy should be carried out before surgery, while in those in stages IIIE-IVE the reverse scheme is more effective in achieving longer survival rates.

[Hernia repair with prolene mesh according to the Lichtenstein technique. Results of 692 cases]. / Ernioplastica con rete in prolene secondo Lichtenstein. Risultati su 692 casi.

BACKGROUND: Inguinal hernia repair with prolene mesh according to Lichtenstein "tension free" technique has gained great acceptance worldwide, showing efficacy to consolidate the posterior wall of the inguinal canal and to reduce recurrence risk because of tension on suture lines and postoperative pain. Personal experience of 692 hernias treated with this technique is reported. METHODS: From January 1989 to December 1997, 692 patients were treated according to Lichtenstein at the General Surgery Department of the San Gerardo Hospital. Mean age was 60 years (range 18-88) with a male: female ratio of 13:1. Surgery was performed under local anesthesia in 185 cases, under epidural anesthesia in 317 and under general anesthesia in 190. Hernia was primitive in 647 cases (411 obliquo-external and 236 direct), while in 45 patients it was a recurrent hernia. In this series, 619 patients had monolateral inguinal hernia, while 73 had a bilateral one. In 40 cases hernia was incarcerated and in 8 strangulated. RESULTS: Mean hospital stay was 2.3 days (range 1-8). Eleven (1.6%) early complications, were observed, with one periprosthetic infection which resolved after patch removal, 3 hematomas, 2 seromas and 2 wound infections. Furthermore, there were 32 (4.6%) late complications with only one recurrence (0.14%) in this series and 25 cases of persistent nerve irritation. CONCLUSIONS: The results obtained with Lichtenstein "tension free" repairs of inguinal hernias confirmed this technique as easy to perform, also under local anesthesia, and associated with low rates of complications and without recurrences.

[Sequential endo-laparoscopic treatment in patients with common bile calculi]. / Trattamento sequenziale endo-laparoscopico in pazienti affetti da calcolosi colecisto-coledocica.

BACKGROUND: Laparoscopic treatment of common bile duct (CBD) stones is gaining great acceptance worldwide, but actually it requires skills and technologies too expensive for a great part of general surgeons. So endoscopic removal of CBD stones before cholecystectomy is usually performed. Since 1991 in our department we started a policy of selective preoperative cholangiopancreatography (ERCP) in patients suspected for choledocholithiasis and waiting for laparoscopic cholecystectomy. METHODS: A retrospective study has been made on a population of 1100 patients who underwent elective laparoscopic cholecystectomy in the period between January 1991 and December 1997. They were 391 male and 719 female with a mean age of 52 years, 126 of whom (11.5%) were selected to have ERCP preoperatively because they had clinical, biochemical and ultrasound signs of the presence of common bile duct stones (CBDS). RESULTS: Successful cannulation of the CBD was achieved in 124 cases (98.4%), with failures due to ampullary diverticula. In 7 cases (5.5%) a precut was necessary to obtain cannulation. Sphincterotomy was performed in 113 patients (89.7%). In 93 patients (73.8%) stones were found (87 macrolithiasis and 6 microlithiasis); in 91 (97.8%) stones were removed in one (87) or two (4) endoscopic session. There were 2 major complications (one bleeding and one severe pancreatitis) due to ERCP or a sphincterotomy. Two patients developed symptoms from unsuspected common bile duct stones after LC and were removed endoscopically. No complications during LC were due to ERCP or ES. CONCLUSIONS: Selective preoperative ERCP is an effective way of clearing the CBD stones before laparoscopic cholecystectomy, with low rate of complications related to endoscopic and laparoscopic procedures, and short mean hospital stay (5.5 days), according to the concept of minimally invasive treatment.

The implantable cardioverter defibrillator in primary prevention: a revision of monocentric study group.

AIMS: To evaluate the outcome of a population implanted with an implantable cardioverter defibrillator (ICD) for primary prevention in terms of mortality, morbidity and appropriate and inappropriate interventions. Secondly, to compare the performances of single-chamber vs. dual-chamber devices. METHODS: We examined all patients with CAD or CMD who received an ICD in primary prevention with at least 6 months of follow-up. For each patient were evaluated, primarily, survival, complications related to the implantation and performance of the device (antitachycardia pacing/shock). RESULTS: Of 193 patients, 163 were men (84.5). Mean age was 64.4 ± 10 years. One hundred and twenty patients (62%) were affected by CAD and 73 (38%) by CMD. The ejection fraction was 26 ± 6%. Fifty-three patients (27.5%) received a dual-chamber ICD, whereas 140 (72.5%) received a single-chamber ICD. There were periprocedural complications in 5.2% of the patients. At a mean follow-up of 49.9 months, 55 patients (28.5%) died. Appropriate interventions were documented in 40 patients (20.7%). In 36 patients (18%), inappropriate interventions occurred. Patients implanted with dual-chamber ICD had an overall mortality of 17% compared to 32.4% for those implanted with single-chamber ICD (P = 0.029). Mortality was higher in patients with CAD (33.9%) (P = 0.032). Among the fatalities, 69% occurred in patients who had an ejection fraction 25% or less at the time of implantation and 31% in patients with an ejection fraction greater than 25% (P = 0.013). CONCLUSIONS: The 4-year survival was 72%. The overall mortality was higher in patients with CAD. More than two-thirds of the deceased had an ejection fraction less than 25%. The dual-chamber ICD patients had a significantly lower mortality rate.

Lesiones en la sustancia blanca en el paciente anciano: Utilización de la terminología adecuada / White matter lesions in an elderly patient: Using the proper terminology

En Neurorradiología los cambios de la sustancia blanca periventricular o subcortical en pacientes ancianos son descritos generalmente con leucoaraiosis, fenómenos hipóxico-isquémicos crónicos, leucoencefalopatía microangiopática o simplemente con alteraciones en la densidad o intensidad según el método elegido. Sin embargo, ¿es correcto el empleo de estas denominaciones?, ¿funcionan como sinónimos?, ¿tienen un mismo mecanismo de producción? Las lesiones que afectan a la sustancia blanca se aprecian hipodensas en tomografía computada, hiperintensas en las secuencias ponderadas en T2 o FLAIR e hipointensas en la resonancia magnética en ponderación T1. Describimos las distintas entidades que pueden afectar selectivamente la sustancia blanca en el paciente anciano y sus probables mecanismos de acción, para establecer una correcta denominación y realizar los diagnósticos diferenciales.

In Neuroradiology the changes in the deep or sub-cortical white matter in elderly people are generally described as leukoaraiosis, chronic hypoxic-ischaemic processes, microangiopathic leucoencephalopathy, or they are simply mentioned as density or intensity changes according to the selected imaging method. However, are these terms correct?, Are they synonyms?, Do they have the same aetiology? The lesions that affect white matter are hypodense in computed tomography, hyperintense in T2-weighted or FLAIR, or hypointense in T1 images in magnetic resonance. A description is presented on the different conditions that can selectively affect the white matter in the elderly patient and their probable mechanisms of action in order to establish a correct nomenclature, as well as make differential diagnoses.