Autogreffe de cartilage costal après échec d’une trapézectomie-ligamentoplastie

We report the case of a 48-year-old woman who underwent a revision procedure to insert a costochondral autograft after failed trapeziectomy-ligamentoplasty. Clinical outcome was assessed at 3, 6, 12, and 24 months and compared with the preoperative situation. Pain (VAS), force (key pinch and grasp), writing capacity, use of an ignition key, and range of motion of the trapeziometacarpal joint in abduction and opposition were noted. The VAS demonstrated improvement in pain and the patient was able to use an ignition key but grasp force and joint range of motion remained unchanged. There was no complication at the graft harvesting site. This technique appears to be a useful salvage method after failed trapiezectomy.

La distraction osseuse progressive au niveau métacarpien ou phalangien chez l'enfant

We report the results of bone lengthening using progressive distraction performed for congenital hand deformities in 12 children between 1998 and 2004. The series is retrospective. Patients were aged between 2 and 11 years. The distraction site was metacarpal in 9 cases and phalangeal in 3 cases. The Mondéal micro distraction device was used. The lengthening procedure was a callotasis with a 0.25 to 0.5 mm/day distraction pace in all cases. The final mean lengthening was 16 mm, and the mean treatment duration was 107 days. The complication rate was 33%. The distraction procedure is described in detail. It is feasible in very young patients as a micro distraction device is used. Family education may prevent complications. This therapeutic procedure gave functional improvement without impairment of distal sensitivity.

Niosomes as carriers for tretinoin. III. A study into the in vitro cutaneous delivery of vesicle-incorporated tretinoin

The influence of drug thermodynamic activity and niosome composition, size, lamellarity and charge on the (trans)dermal delivery of tretinoin (TRA) was studied. For this purpose, tretinoin was incorporated at saturated and unsaturated concentrations in both multilamellar (MLV) and unilamellar (UV) vesicular formulations using two different commercial mixtures of alkyl polyglucosides: octyl-decyl polyglucoside and decyl polyglucoside. Positively and negatively charged vesicular formulations were prepared using either stearylamine or dicetylphosphate as a charge inducer. Niosomes made with polyoxyethylene (4) lauryl ether and liposomes made with soy phosphatidylcholine were also prepared and studied. Vesicular formulations were characterised by transmission electron microscopy and optical and light polarized microscopy for vesicle formation and morphology, and by dynamic laser light scattering for size distribution. The effect of the vesicular incorporation of tretinoin on its (trans)dermal delivery through the newborn pig skin was also investigated in vitro using Franz cells, in comparison with a commercial formulation of the drug (RetinA). The amount of tretinoin delivered through and accumulated in the several skin layers was detected by HPLC. Overall, obtained results showed that tretinoin cutaneous delivery is strongly affected by vesicle composition and thermodynamic activity of the drug. In particular, small, negatively charged niosomal formulations, which are saturated with tretinoin, have shown to give higher cutaneous drug retention than both liposomes and commercial formulation. Moreover, interactions between skin and vesicles seem to depend on physico-chemical properties of the main component of the vesicular bilayer.

Diclofenac-beta-cyclodextrin binary systems: physicochemical characterization and in vitro dissolution and diffusion studies

The aim of this work was to study the influence of beta-cyclodextrin (beta-CD) on the biopharmaceutic properties of diclofenac (DCF). To this purpose the physicochemical characterization of diclofenac-beta-cyclodextrin binary systems was performed both in solution and solid state. Solid phase characterization was performed using differential scanning calorimetry (DSC), powder x-ray diffractometry (XRD), and Fourier transform infrared spectroscopy (FTIR). Phase solubility analyses, and in vitro permeation experiments through a synthetic membrane were performed in solution. Moreover, DCF/beta-CD interactions were studied in DMSO by 1H nuclear magnetic resonance (NMR) spectroscopy. The effects of different preparation methods and drug-to-beta-CD molar ratios were also evaluated. Phase solubility studies revealed 1:1 M complexation of DCF when the freeze-drying method was used for the preparation of the binary system. The true inclusion for the freeze-dried binary system was confirmed by 1H NMR spectroscopy, DSC, powder XRD, and IR studies. The dissolution study revealed that the drug dissolution rate was improved by the presence of CDs and the highest and promptest release was obtained with the freeze-dried binary system. Diffusion experiments through a silicone membrane showed that DCF diffusion was higher from the saturated drug solution (control) than the freeze-dried inclusion complexes, prepared using different DCF-beta-CD molar ratios. However, the presence of the inclusion complex was able to stabilize the system giving rise to a more regular diffusion profile.

Liposomal incorporation of Artemisia arborescens L. essential oil and in vitro antiviral activity

The effect of liposomal inclusion on the in vitro antiherpetic activity of Artemisia arborescens L. essential oil was investigated. In order to study the influence of vesicle structure and composition on the antiviral activity of the vesicle-incorporated oil, multilamellar (MLV) and unilamellar (SUV) positively charged liposomes were prepared by the film method and sonication. Liposomes were obtained from hydrogenated (P90H) and non-hydrogenated (P90) soy phosphatidylcholine. Formulations were examined for their stability for over one year, monitoring the oil leakage from vesicles and the average size distribution. The antiviral activity was studied against Herpes simplex virus type 1 (HSV-1) by a quantitative tetrazolium-based colorimetric method. Results showed that Artemisia essential oil can be incorporated in good amounts in the prepared vesicular dispersions. Stability studies pointed out that vesicle dispersions were very stable for at least six months and neither oil leakage nor vesicle size alteration occurred during this period. After one year of storage oil retention was still good, but vesicle fusion was present. Antiviral assays demonstrated that the liposomal incorporation of A. arborescens essential oil enhanced its in vitro antiherpetic activity especially when vesicles were made with P90H. On the contrary, no significant difference in antiviral activity was observed between the free and SUV-incorporated oil.

Liposomes as carriers for dermal delivery of tretinoin: in vitro evaluation of drug permeation and vesicle-skin interaction

The influence of liposome composition, size, lamellarity and charge on the (trans)dermal delivery of tretinoin (TRA) was studied. For this purpose we studied both multilamellar (MLV) or unilamellar (UV) liposomes. Positively or negatively charged liposomes were obtained using either hydrogenated (Phospholipon90H) or non-hydrogenated soy phosphatidylcholine (Phospholipon90) and cholesterol, in combination with stearylamine or dicetylphosphate. Liposomal formulations were characterized by transmission electron microscopy (TEM) and optical and light polarized microscopy for vesicle formation and morphology, and by dynamic laser light scattering for size distribution. In order to obtain more information about the stability and the thermodynamic activity of the liposomal tretinoin, TRA diffusion through a lipophilic membrane was investigated. The effect of the vesicular incorporation of tretinoin on its accumulation into the newborn pig skin was also studied. The experiments were performed in vitro using Franz cells in occlusive conditions and were compared to three different controls. The tretinoin amount delivered through and accumulated in the several skin layers was detected by HPLC. Furthermore, TEM in combination with osmium tetroxide was used to visualize the skin structure after the liposomal administration. Overall obtained results showed that liposomes may be an interesting carrier for tretinoin in skin disease treatment, when appropriate formulations are used. In particular, negatively charged liposomes strongly improved newborn pig skin hydration and TRA retention, though no evidence of intact vesicle penetration was found.

Noise in ecosystems: a short review

Noise, through its interaction with the nonlinearity of the living systems, can give rise to counter-intuitive phenomena such as stochastic resonance, noise-delayed extinction, temporal oscillations, and spatial patterns. In this paper we briefly review the noise-induced effects in three different ecosystems: (i) two competing species; (ii) three interacting species, one predator and two preys, and (iii) N-interacting species. The transient dynamics of these ecosystems are analyzed through generalized Lotka-Volterra equations in the presence of multiplicative noise, which models the interaction between the species and the environment. The interaction parameter between the species is random in cases (i) and (iii), and a periodical function, which accounts for the environmental temperature, in case (ii). We find noise-induced phenomena such as quasi-deterministic oscillations, stochastic resonance, noise-delayed extinction, and noise-induced pattern formation with nonmonotonic behaviors of patterns areas and of the density correlation as a function of the multiplicative noise intensity. The asymptotic behavior of the time average of the i(th) population when the ecosystem is composed of a great number of interacting species is obtained and the effect of the noise on the asymptotic probability distributions of the populations is discussed.

Phospholipid Vesicles as Carriers in Aquaculture: Preparation and Stability Study of Thiamine Hydrochloride-Loaded Liposomes

The aim of this work is to study liposomes as carriers of nutrients and therapeutic agents in aquaculture with Venerupis decussatus and Venerupis pullastra larvae. Multilamellar (MLVs) and large unilamellar (LUVs) vesicles were prepared from a commercial mixture of soy phosphatidylcholine, rich in unsaturated and polyunsaturated fatty acids, cholesterol, and hydrated with a solution of vitamin B1 both in distilled and sea water. Carboxyfluorescein-loaded liposomes were also prepared in order to test the uptake of vesicles by larvae. The stability of formulations was checked by monitoring the size of vesicles and their drug leakage. In order to limit the vitamin loss, liposome freeze-drying was studied. Dried formulations were also prepared by using different amounts of trehalose as cryoprotectant. We found that freeze-dried vesicles, rehydrated after two weeks, had a vitamin retention (R%) equal to 95%, while their diameter significantly increased. By contrast, liposomes freeze-dried in the presence of trehalose displayed a lower R%, but higher bilayer stability. Finally, when CF-loaded vesicles were added to Venerupis decussatus and Venerupis pullastra larvae incubated in filtered sea water, a bright and diffused fluorescence was present in most of the larvae, a fact which can be regarded as evidence of liposome uptake by Venerupis larvae.

Early experience with the minimal extracorporeal circulation system (MECC) during thoracoabdominal aortic aneurysm repair

AIM

The purpose of this report is to describe our early experience with a minimal extracorporeal circulation system (MECC), a compact closed heparin coated system consisting of a centrifugal pump and a membrane oxygenator, during thoracoabdominal aortic aneurysm (TAAA) repair.

METHODS

Between January and December 2002 the MECC system was employed in seven consecutive patients (four TAAA type II, two TAAA type I and one TAAA type III according to the Crawford classification). In all patients distal aortic, selective renal and visceral perfusion was performed with this compact closed heparin coated system consisting of a centrifugal pump and a membrane oxygenator.

RESULTS

The MECC system was used in all cases with no technical malfunctions. Six out seven patients were discharged from the unit. One patient developed paraplegia after TAAA repair and died on the third post-operative day from multi-organ failure. In this case the total spinal ischaemic time was 120 min and the distal aortic perfusion pressure was <50 mmHg. No cardiac, cerebral, renal, hepatic or bleeding complications were recorded in the remaining six patients.

CONCLUSION

Our early experience with MECC during TAAA repair showed that it is feasible for distal aortic spinal and visceral selective perfusion. Further large clinical trials are required to determine the efficacy of this technique.

Niosomes as carriers for tretinoin. II. Influence of vesicular incorporation on tretinoin photostability

In this work, we compared the chemical stability of tretinoin (TRA) in methanol and in vesicular suspensions exposed both to UV and artificial daylight conditions with the aim of evaluating the potential of niosomes as topical carriers capable of improving the stability of photosensitive drugs. Tretinoin-loaded niosomes were prepared from polyoxyethylene (4) lauryl ether (Brij 30), sorbitan esters (Span 40 and Span 60) and a commercial mixture of octyl/decyl polyglucosides (Triton CG110). Liposomes made from hydrogenated (P90H) and non-hydrogenated (P90) soy phosphatidylcholines were also prepared and studied. In order to evaluate the influence of vesicle structure on the photostability of tretinoin, TRA-loaded vesicles were prepared by the film hydration method, extrusion technique and sonication. After UV irradiation, TRA dissolved in methanol degraded very quickly while the incorporation in vesicles always led to a reduction of the photodegradation process. The photoprotection offered by vesicles varied depending on the vesicle structure and composition. After fluorescent light irradiation for 21 days, not all the studied vesicular formulations improved TRA stability when compared with the free drug in methanol. Tretinoin incorporated in P90 or Span vesicles presented a half-life shorter or very close to that of the free drug. However, the inclusion of TRA in P90H liposomes and Brij 30 or Triton CG110 niosomes retarded the drug photodegradation.

Intra-operative assessment of technical defects after carotid endarterectomy: a comparison between angiography and colour duplex scan

We compared the intra-operative diagnostic value of CDS vs IA-DSA in identifying major and minor technical defects after CEA. Between August 1997 and December 1998, 138 consecutive patients undergoing 141 carotid endarterectomies were intra-operatively investigated with colour duplex scan and intra-arterial digital subtraction angiography. Thirty-six (25.5%) technical defects were identified. Four (11.1%) major defects were detected by both methods and they were immediately corrected. Fifteen (41.6%) minor defects were detected by both methods, thirteen (36.1%) minor defects were detected by colour duplex but ignored by angiography. Angiography detected four (11.1%) kinkings missed with the colour duplex. The overall sensitivity of both methods for major defect was 100%. The sensitivity of colour duplex for minor defects was 87% vs 59% for angiography. On the basis of our study, colour duplex could be considered the choice method for quality control after carotid endarterectomy.

Niosomes as carriers for tretinoin. I. Preparation and properties

Tretinoin-loaded niosomes were prepared from polyoxyethylene (4) lauryl ether, sorbitan esters and a commercial mixture of octyl/decyl polyglucosides, in the presence of cholesterol and dicetyl phosphate. Liposomes made of hydrogenated and non-hydrogenated phosphatidylcholine were also prepared as a comparison reference. A study was made of the influence of vesicle composition and preparation method on the vesicle structure (MLV, LUV, SUV), size distribution, entrapment efficiency and in vitro release of incorporated tretinoin. Results showed that in the presence of cholesterol all the amphiphiles used were able to form stable vesicle dispersions with or without tretinoin. Vesicle sizes were dependent on the preparation method, bilayer composition and drug load. Multilamellar (MLV) vesicles were larger than extruded (LUV) and sonicated (SUV) vesicles while drug-loaded vesicles were generally smaller than empty ones. Entrapment efficiencies of tretinoin were always very high especially for multilamellar (91-99%) and extruded (88-98%) vesicles. The in vitro release of tretinoin from the prepared vesicular formulations was studied using the vertical Franz diffusion cells. The rate of drug release through a Silastic membrane from a liposomal and niosomal tretinoin dispersion was generally faster than from a tretinoin solution. Release data showed that tretinoin delivery is mainly affected by the vesicular structure and that tretinoin delivery increased from MLVs to LUVs to SUVs.

Stability studies of new cosmetic formulations with vegetable extracts as functional agents

A formulation study, using increasing amounts of Sepigel 305 as an emulsifier, has been carried out to find new O/W emulsions and value their stability also in presence of vegetable extracts. Stability results have been compared with those obtained from formulations described in the National Formulary of Italian Pharmacopoeia X and functionalised by us with the same vegetable extracts. By using centrifugation and accelerated ageing tests capable of bringing out the gelling and thermostability properties of Sepigel 305, the study emphasised that the new gel emulsions have a greater stability compared to the other formulations.

A sensitive method to assay the xanthine oxidase activity in primary cultures of cerebellar granule cells

Since xanthine oxidase (XO, Xanthine:oxidoreductase, E.C.1.2.3.22) is a key enzyme in reactive oxygen specie formation which plays a major role in cell oxidative stress, the availability of a sensitive and simple assay useful to detect its activity in monolayer cell cultures is worthwhile. In order to achieve this, we developed a method in which the conversion of pterine into isoxanthopterin is monitored fluorimetrically. Temperature assay was 50 degrees C. The activity of XO was detected in cerebellar granule cells exposed to glutamate. Since XO is formed from protease-dependent xanthine dehydrogenase processing, its activity appearance was found to be prevented by the protease inhibitor, leupeptin, as well as the glutamate NMDA-receptor inhibitor, MK-801, and the Ca(++) complexing agent, EGTA. The reported novel protocol, at variance with a conventional method, is shown to be a simple, fast, sensitive and relatively cheap method to assay XO activity. In addition, the reported assay can be applied to any cell type in culture.

The riboflavin/FAD cycle in rat liver mitochondria

Here we provide evidence that mitochondria isolated from rat liver can synthesize FAD from riboflavin that has been taken up and from endogenous ATP. Riboflavin uptake takes place via a carrier-mediated process, as shown by the inverse relationship between fold accumulation and riboflavin concentration, the saturation kinetics [riboflavin Km and Vmax values were 4.4+/-1.3 microM and 35+/-5 pmol x min(-1) (mg protein)(-1), respectively] and the inhibition shown by the thiol reagent mersalyl, which cannot enter the mitochondria. FAD synthesis is due to the existence of FAD synthetase (EC 2.7.7.2), localized in the matrix, which has as a substrate pair mitochondrial ATP and FMN synthesized from taken up riboflavin via the putative mitochondrial riboflavin kinase. In the light of certain features, including the protein thermal stability and molecular mass, mitochondrial FAD synthetase differs from the cytosolic isoenzyme. Apparent Km and apparent Vmax values for FMN were 5.4+/-0.9 microM and 22.9+/-1.4 pmol x min(-1) x (mg matrix protein)(-1), respectively. Newly synthesized FAD inside the mitochondria can be exported from the mitochondria in a manner sensitive to atractyloside but insensitive to mersalyl. The occurrence of the riboflavin/FAD cycle is proposed to account for riboflavin uptake in mitochondria biogenesis and riboflavin recovery in mitochondrial flavoprotein degradation; both are prerequisites for the synthesis of mitochondrial flavin cofactors.

AZT inhibition of the ADP/ATP antiport in isolated rat heart mitochondria

In order to gain insight into the mechanism by which AZT affects mitochondrial metabolism in heart, leading to the ATP deficiency syndrome, the capability of AZT to affect certain mitochondrial translocators was checked in coupled mitochondria isolated from rat heart. AZT was found to strongly inhibit the ADP/ATP antiport, in a competitive manner (Ki 7 microM), as photometrically measured. Contrarily, the rate of the succinate/malate exchange via the dicarboxylate carrier, of the oxaloacetate uptake via the oxodicarboxylate carrier and of cis-aconitate uptake via the tricarboxylate carrier was found to be unchanged in the presence of AZT.

Warfarin induced skin necrosis

BACKGROUND

Warfarin induced skin necrosis is a rare complication with a prevalence of 0.01-0.1 per cent. It was first described in 1943.

METHODS

A literature review was undertaken using Medline; all relevant papers on this rare compli-cation of warfarin therapy were used.

RESULTS

There are several adverse skin manifestations associated with the use of oral anticoagulants, ranging from ecchymoses and purpura, haemorrhagic necrosis, maculopapular vesicular urticarial eruptions to purple toes. This article concentrates mainly on warfarin induced skin necrosis. The syndrome typically occurs during the first few days of warfarin therapy, often in association with the administration of a large initial loading dose of the drug. Although the precise nature of the disease is still unknown, advances in knowledge about protein C, protein S and antithrombin III anticoagulant pathways have led to a better understanding of the mechanisms involved in pathogenesis. Differential diagnosis between warfarin induced skin necrosis and necrotizing fasciitis, venous gangrene and other causes of skin necrosis may be difficult; the disease may also be confused with other dermatological entities.

CONCLUSION

Warfarin induced skin necrosis, while rare, is an important complication. All surgeons should be aware of its existence.

Inhibition of nucleoside diphosphate kinase in rat liver mitochondria by added 3'-azido-3'-deoxythymidine

The effect of 3'-azido-3'-deoxythymidine on nucleoside diphosphate kinase of isolated rat liver mitochondria has been studied. This is done by monitoring the increase in the rate of oxygen uptake by nucleoside diphosphate (TDP, UDP, CDP or GDP) addition to mitochondria in state 4. It is shown that 3'-azido-3'-deoxythymidine inhibits the mitochondrial nucleoside diphosphate kinase in a competitive manner, with a Ki value of about 10 microM as measured for each tested nucleoside diphosphate. It is also shown that high concentrations of GDP prevent 3'-azido-3'-deoxythymidine inhibition of the nucleoside diphosphate kinase.

Mitochondria as cell targets of AZT (zidovudine)

1. The subject of this review is the interaction between AZT (zidovudine) and mitochondria as described in papers dealing with AZT therapy both in AIDS patients and in model systems--that is, in cultured cells and in isolated mitochondria. 2. The structure and function of mitochondria are briefly described with discussion of the theoretical frame for a detailed bioenergetic investigation. 3. Experimental work is reported showing that mitochondria are cell AZT targets: changes in the structure and function induced by long-term AZT therapy as investigated both in AIDS patients and in model systems. 4. The AZT inhibition of energy-supplying reactions is considered in detail in studies dealing with long-term treatment and studies in which AZT was added to isolated mitochondria. In particular, adenylate kinase, ADP/ATP translocase and DNA polymerase gamma are reported as molecular targets of AZT. 5. Some perspectives of AZT therapy from the study of the effect of AZT on mitochondrion biochemistry are briefly reported.

Rat liver mitochondria can hydrolyse thiamine pyrophosphate to thiamine monophosphate which can cross the mitochondrial membrane in a carrier-mediated process

We show here that TPP --> TMP conversion can take place in rat liver mitochondria. This occurs via the novel, putative TPP pyrophosphatase localised in the mitochondrial matrix, as shown both by digitonin titration and by an HPLC enzyme assay carried out on the mitochondrial matrix fraction. Certain features of the reaction, including the substrate and pH dependence, are reported. Additional evidence is given that externally added TMP can cross the mitochondrial membrane in a manner consistent with the occurrence of a carrier-mediated process. This can occur both via the TPP translocator and via a novel translocator, inhibited by CAT but different from the ADP/ATP carrier.

3'-Azido-3'-deoxythmidine uptake into isolated rat liver mitochondria and impairment of ADP/ATP translocator

To gain some insight into the mechanism by which 3'-azido-3'-deoxythymidine (AZT) impairs mitochondrial metabolism, [14C]AZT uptake by rat liver mitochondria (RLM) in vitro was investigated. AZT accumulated in mitochondria in a time-dependent manner and entered the mitochondrial matrix. The rate of AZT uptake into mitochondria showed a hyperbolic dependence on the drug concentration and was inhibited by mersalyl, a thiol reagent that cannot enter mitochondria, thus showing that a membrane protein is involved in AZT transport. Investigation into the capability of AZT to affect certain mitochondrial carriers demonstrated that AZT was able to impair the ADP/ATP translocator, but had no effect on Pi, dicarboxylate, tricarboxylate, or oxodicarboxylate carriers. AZT inhibited ADP/ATP antiport in either mitochondria or mitoplasts in a competitive manner with different sensitivity (Ki values were 18.3 +/- 2.9 and 70.2 +/- 5.8 microM, respectively). Consistent with this were isotopic measurements showing that AZT accumulates in the intermembrane space. AZT does not use ADP/ATP carrier to enter mitochondria, as shown by the failure of both carboxyatractyloside (CAT) to inhibit AZT transport into mitochondria and AZT to induce ATP efflux from ATP-loaded mitochondria. ADP/ATP translocator impairment by AZT as one of the biochemical processes responsible for the ATP deficiency syndrome is discussed.

[Genetic damage in human tumors associated with particular behavioral or occupational exposures]

We have conducted a review of the literature on chemical exposures (known carcinogens), mutations in oncogenes/tumor suppressor genes and the occurrence of malignancies. The underlying hypothesis of the studies on this issue is that specific carcinogenic chemicals induce specific mutations in relevant genes ("fingerprints") and that the latter are involved in the causal pathway that leads to cancer. The confirmation of such hypothesis is conditioned by limitations of the available techniques, and by the design of the epidemiological studies. We discuss methodological problems inherent in the identification of oncogene mutations within studies in humans, such as the limited sensitivity of molecular techniques, which may lead to a bias toward the null. Although several studies--concerning mainly lung or bladder cancer and tobacco smoking or some occupational exposures--give support to the theory of "fingerprints", further evidence is warranted.

[Intestinal carcinoid. A propos of a case]

In this paper the authors report a case of carcinoid neoplasm in a rare localization like sigmoid colon. They describe the clinical and biological aspects of this kind of tumors, with particular regard to the tumor site and its biochemical products. A rational and prompt clinical approach to this neoplasm is considered important for the good chance of long survivals, achievable in the case of early diagnosis.

Mesotheliomas following exposure to asbestos used in railroads: 130 Italian cases

The available knowledge on the oncogenic risks of asbestos, the data on the uses of asbestos in railroads, with particular regard to the Italian State Railroads (Ferrovie dello Stato = FS), and the groups at risk due to the exposure to asbestos used in railroads were briefly reviewed. The available data on the pathological effects of such exposure, and particularly on the onset of mesotheliomas among machinists and other railroad workers, were also summarized. One hundred and thirty cases of mesothelioma (122 pleural, 1 pericardial, 6 peritoneal and 1 pleuro-peritoneal), related to the exposure to asbestos used in railroads, observed in various Italian regions, were reported. Fifty-three of these cases (among which 49 reported in the Emilia Romagna Region) were submitted to a detailed study at the Bologna Institute of Oncology. Seventy-seven cases of mesothelioma occurred among occupationally exposed FS workers, in particular machinists; 45 cases occurred among rolling-stock machinists and workers engaged in the repair and demolition of the rails of workshops not belonging to the FS; 3 cases occurred among travelling workers of rolling-stock, not belonging to the FS; and 5 cases were found in family members (1 daughter, 3 wives and 1 sister) of railroad workers. This series of cases, together with similar data from the literature, proves the existence of an actual health risk due to asbestos used in railroads, and indicates its gravity. On the basis of the available data, the following steps are considered necessary: the promotion of systematic epidemiological investigations, the adoption of preventive measures, the performance of medical oncological surveillance, and the automatic compensation for tumours following the exposure to the asbestos used in railroads.

Mesotheliomas following exposure to asbestos used in sugar refineries: report of 12 Italian cases

Twelve Italian cases of mesothelioma (all the cases but one from the Emilia Romagna Region), following exposure to asbestos used in sugar refinery plants, are reported. Eleven cases arose in workers occupationally exposed, and one in the daughter of an exposed worker, following family contact. Eleven of the cases were pleural and one peritoneal. In the 11 cases following occupational exposure the average latency time was 36.0 (range 23-48) years, and the average age at onset was 63.4 years. In the case which followed family contact, the latency time and the age of the onset were 37 years. This represents the largest series of cases of mesothelioma due to the asbestos present in sugar refinery plants reported to date in the scientific literature. While these cases demonstrate the risk of asbestos mesothelioma in the sugar refinery industry, they in no way give the dimension of the pathological effects of asbestos (and man-made mineral fibres) used in this industry. To assess this risk further research is suggested.

Gastric Banding for Treatment of Morbid Obesity: Preliminary Results

BACKGROUND: gastric banding (GB) has been used for treatment of morbid obesity. METHODS: a banding device, introduced by Broadbent and consisting of a self-blocking nylon strip covered with a silicone tube, was used in 13 patients who have completed 1-year follow-up. This device was used for its mechanical properties, biocompatibility, ease of insertion and low cost. RESULTS: at 1 year, mean excess weight loss was 51.6%, with all but one patient losing more than 25% of excess weight. Associated illnesses resolved. There were two complications (15%): one patient required band removal for self-induced vomiting and one patient required repair of an incisional hernia. CONCLUSIONS: GB has had good results thus far. Reported differences depend on materials, stoma diameter, pouch size, and developing techniques.

Mechanisms of toxicity of 3'-azido-3'-deoxythymidine. Its interaction with adenylate kinase

Recent experiments from our laboratory have indicated that the inhibitory effect of 3'-azido-3'-deoxythymidine (AZT) on oxidative phosphorylation may occur directly, in addition to being brought about by its inhibition of mtDNA replication. We report here studies on the effect of AZT on adenylate kinase, an enzyme crucial to oxidative phosphorylation. AZT decreased the aromatic residues fluorescence of rabbit muscle adenylate kinase, indicating binding of AZT to the enzyme. Of three other enzymes studied as controls, AZT bound only to those that possessed ATP/ADP binding sites. Up to concentrations of 15 microM, AZT was a more potent effector of fluorescence quenching than were ATP, ADP, AMP, and the AZT control, deoxythymidine. AZT strongly inhibited adenylate kinase in the direction of ATP synthesis (Ki, 8 microM), the inhibition being of the partial competitive type, whereas deoxythymidine inhibition, also partially competitive, was much weaker (Ki, 90 microM). When measured in the direction of ADP synthesis, AZT failed to demonstrate any inhibition at concentrations up to 10 microM. Experiments on isolated intact rat liver mitochondria with the enzyme activity measured in both directions confirmed the isolated enzyme results. Respiratory control by these mitochondria was not affected by AZT. The finding of AZT affinity for ATP/ADP binding sites may open new avenues of approach to the study of AZT toxicity.

[Clarithromycin in the treatment of oral infections]

The authors show the results of a clinical study to test the efficacy and the tolerance of clarithromycin when used in the treatment of odontological infections. Forty-one subjects were selected for the study. All the subjects were affected by odontological infections and needed antibiotic therapy. The results obtained are satisfactory and demonstrate the effectiveness of the use of clarithromycin in the treatment of odontological infections.

Study of spermine and spermidine effects on Saccharomyces cerevisiae. Polyamine production in different growth conditions and in the presence of interleukin-2

The role of polyamines during cell growth is still uncertain. Yeast cells possess an amine pathway similar to that described for animal cells. We studied the relationship between growth and polyamine production in yeast cells of Saccharomyces cerevisiae grown under various conditions. Polyamines were determined in homogenates of yeast cells by a rapid enzymatic assay, confirmed by thin-layer chromatography. Polyamine production is dependent on the growth conditions. The effects of spermine, spermidine, and interleukin-2 on yeast cells were investigated. Exogenous polyamines affected the endogenous pathway, and interleukin-2 treatment increase yeast growth and polyamine production.

Immediate electronystagmography in the diagnosis of the dizzy patient

STUDY OBJECTIVES

To determine whether the results of electronystagmography (ENG) testing improve an emergency physician's diagnosis of dizziness.

DESIGN

Prospective, one-year.

SETTING

University and three community hospital emergency departments.

TYPE OF PARTICIPANTS

Ninety-three consecutive patients presenting with dizziness.

INTERVENTIONS

ED impression was recorded after complete ED evaluation. An ENG was performed within one hour by an audiologist, who gave a reading of "central," "peripheral," or "normal." The result was given to the emergency physician, who was invited to revise his or her impression (the "ED impression after ENG result"). Final diagnosis was based on the ED impression and by contact with the patient's physician(s) as well as the patient by telephone after one and four weeks. Accuracy of ENG was assessed by comparing ENG reading with the final diagnosis using the chi(2) test. In addition, the contribution of ENG to ED diagnosis was assessed by comparing the accuracy of the ED impression after ENG reading with the ED impression alone using McNemar's test (hit versus no-hit).

MEASUREMENTS AND MAIN RESULTS

Both ED impression and the ENG significantly correlated with the final diagnostic category (chi(2) = 104.9, P < .001; chi(2) = 70.79, P < .001, respectively). ENG correctly diagnosed nine of 11 patients with central dizziness. Of 23 patients with undetermined cause after ED evaluation, ENG correctly identified seven patients with peripheral dizziness and three with central dizziness. ED impression after ENG reading was more accurate than ED impression alone (chi(2) = 6.13, P < .05).

CONCLUSION

Emergency physicians correctly categorized most dizzy patients, but audiologist performance and interpretation of an ENG significantly improved this categorization. ENG may have the potential to identify clinically unsuspected central dizziness and to categorize dizziness of "unknown" cause. Further study is needed to determine whether ENG could be performed by modifying certain types of heart monitors available in the ED.

[Postoperative venous thromboembolism in bariatric surgery]

The authors discuss the problem of venous thromboembolism as a complication of bariatric surgery. They consider obese patients at risk for these complications, even if different opinions exist about this topic in the literature. They report their experience in bariatric surgery consisting of 53 patients submitted to biliopancreatic diversion. Antithrombotic prophylaxis consisted for every patient in elastic bandaging of the lower limbs, preoperative hemodilution, early post-operative mobilization, and subcutaneous heparin. Complications consisted in one popliteo-femoral deep venous thrombosis (DVT) (1.6%), and two pulmonary embolisms (PE) (3.2%) of which one caused patient's death; total morbidity for venous thromboembolism. These results compared with literature are similar with other series of bariatriac surgery and slightly higher than general surgery series. This difference is not however significant. Even in the absence of this significance, thromboembolism, as desumed from more than 2900 cases considered in the literature, remains the main cause of morbidity and mortality in the post-operative course of bariatric surgery patients, deserving particular attention in terms of prevention, also because of difficulty existing in early clinical diagnosis of DVT in obese people. Further studies intended to identify pathogenesis and risk factors of venous thromboembolism in obese people will allow a more correct prophylactic and therapeutic approach.

[Autotransfusion in bariatric surgery]

The authors, after some brief remarks on homologous blood transfusion discuss autotransfusion techniques, and haemodilution principles, they report their experience of autohemotransfusion with preoperative sampling in bariatric surgery, pointing out physiopathologic mechanisms and many advantages.

[Laparocele. A late complication of bariatric surgery]

In this paper the authors consider the problem of incisional hernias as late complications of bariatric surgery. After a description of relationships between obesity and incisional hernias they report their experience on this topic, consisting of 56 patients submitted to bilio-pancreatic diversion between March 1989 and September 1991, for surgical treatment of morbid obesity. Incisional hernias developed in 28% of cases. Analysis of some risk factors like infections, epidemiological patterns, materials and techniques used to suture the abdominal wall, has not allowed identification of significant associations with incisional hernias occurrence. Only early reinterventions (3 cases) have always determined a subsequent development of incisional hernias. The authors confirm the close relationship existing between obesity and incisional hernias. They suggest incisional hernia repair to be undertaken once weight loss has terminated and stabilized, and in the absence of other specific or aspecific morbid obesity surgery complications.

[Prophylactic cholecystectomy in bariatric surgery]

In this paper the authors discuss about prophylactic cholecystectomy in bariatric surgery. Having analyzed the mechanisms that increase bile lithogenicity after bariatric surgery, they evaluate advantages and disadvantages of prophylactic cholecystectomy. They present 53 obese patients submitted to biliopancreatic diversion and prophylactic cholecystectomy for surgical treatment of morbid obesity, because of the high incidence of pathological findings in the specimens and the absence of surgical complications related to cholecystectomy, the authors, in agreement with the literature, suggest routine cholecystectomy as an obvious adjunct to bariatric surgery. This attitude protects against the higher risk of subsequent cholecystectomy and against the misinterpretation of non-invasive diagnostic tests too, because of known limits of echography in obese people.

Determination of heavy metals in animal tissues

During studies on the accumulation of heavy metals in animal organs and tissues, only small samples (0.5-2 g) rich in lipids and having low concentrations of metals are often available. This may lead to loss of metals in the various steps of the analytical procedure. A modified procedure of mineralization for the determination of Pb, Cd and Zn is described, as well as suitable analytical procedures used by the Authors for the determination by atomic absorption spectrophotometry. Results showed that the loss of metals is minimized with these procedures.

Prenatal management of 746 pregnancies at risk for congenital toxoplasmosis

When infection with Toxoplasma gondii occurs during pregnancy, there is a risk that the parasite will cause severe congenital toxoplasmosis. We developed a method of diagnosing and treating congenital toxoplasmosis in utero. Diagnosis was based on the identification of maternal acute infection, followed by culture of fetal blood and amniotic fluid, testing of fetal blood for toxoplasma-specific IgM and nonspecific measures of infection, and ultrasound examination of the fetal brain. Treatment included the administration of antibiotics to all mothers with confirmed acute infection during pregnancy, with more intensive antibiotic treatment of those who had infected fetuses and who chose to continue the pregnancy. We report a prospective study of 746 documented cases of maternal toxoplasma infection, in which the infants were followed for at least three months. Infection was diagnosed antenatally in 39 of 42 fetuses. Twenty-four of the 39 pregnancies were terminated, and 15 were continued. All the mothers were treated with spiramycin throughout pregnancy; if fetal infection was demonstrated, pyrimethamine and either sulfadoxine or sulfadiazine were added to the regimen. Of the 15 fetuses with congenital toxoplasmosis who were carried to term, all but 2, who had chorioretinitis, remained clinically well during follow-up. We conclude that prenatal diagnosis of congenital toxoplasmosis is practical and that prenatal therapy in women who wish to continue their pregnancies reduces the severity of the manifestations of the disease.

[An interesting case of monoclonal component]

The authors present an interesting case of monoclonal component concerning a 61 years old patient, incorrectly identifiable with the IFE technique only. Moreover they describe the analytic methodology used to identify the monoclonal component which resulted to be secreted in three different ways of polymerization.

[Right ventricular infarct and atrioventricular blocks]

Right ventricular infarction in inferior left ventricular infarction is very common. We have examined, by means of equilibrium gated radionuclide angiography, the relationship existing between right ventricular infarction and atrioventricular block. Seventy-two patients with inferior wall myocardial infarction were studied. Thirty-nine of them had ventriculographic evidence of right ventricular infarction. Fifteen of them (38%) had a-v block in the acute phase. Only 3 patients without right ventricular involvement (9%) had a-v block. The occurrence of a-v block is usually explained by the fact that the blood supply to the a-v node depends on the right coronary artery. In the patients with right ventricular involvement, the incidence of a-v block is high just because occlusion of the right coronary artery is proximal to the branch to the a-v node. However, the presence of collateral blood supply to the a-v node makes the occurrence of a-v node not so high as expected.

[Serologic study of toxoplasmosis in an ambulatory population in 1984-1986]

The authors refer the results of a serological investigation about Toxoplasmosis done on 4119 patients during 1984-1986 related to a similar research executed on 2119 patients during 1976-1979. The results show a constant yearly increase of requests of Toxoplasmosis test and a progressive increase of the serologically negative cases. The authors suggest an improvement of Toxoplasmosis epidemiology.