Choice of frequency weighting for the evaluation of weapon noise

This paper describes a laboratory study to choose an appropriate frequency weighting network for predicting the annoyance caused by the noise from small, medium, and large weapons. The results indicate that the annoyance of all three weapon types is the same if the blasts are heard at identical A-weighted SEL's. On the other hand, equal C-weighted SEL's result in large differences in annoyance between the weapon types. The implications of these results for outdoor noise criteria depend on the assumption concerning window condition. If one assumes that people hear the blasts predominantly through open windows, then A-weighted criteria should be appropriate for all the weapon types without any correction (penalty or bonus) for weapon type. On the other hand, if the blasts are heard predominantly through closed windows a penalty of about 5 dB should be applied to the outdoor levels of the large weapons to account for the poorer low-frequency attenuation of the windows.

[Limb salvage in critical ischemia. Our experience]

The aim of this paper is to present our six-year experience in the treatment of critical limb ischaemia, even if in the period (1987-1993) considered the definition of critical ischaemia had been partly reviewed in the publication of the "European Consensus Document on Critical Limb Ischaemia" (March 1989). Two hundred thirty-nine patients have been treated in our Unit for critical limb ischaemia: reconstructive surgery was used in 34% of cases, lumbar sympathectomy or spinal cord stimulation in 17% of cases and pharmacotherapy in 14% of cases. Taking into account arterial and graft patency as well as the percentage of limb salvage, our results were similar to those presented in the literature.

COL1A2 gene (alpha 2 gene of type I collagen) at the haplotype level as a new valuable anthropogenetic marker: a study on Sardinians

Sardinians, a population with many distinct anthropogenetic features, has been studied for the COLIA1 and COLIA2 genes at the DNA level for two purposes: to look for new RFLPs (restriction fragment length polymorphisms) and to study the distribution of three known COLIA2 RFLPs (EcoRI, RsaI, MspI) at both the allele and the haplotype levels. None of the eleven enzyme-probe systems examined led to the discovery of a new polymorphism. The following frequency q was found for the less common allele of the three RFLPs: EcoRI, q(+) = 0.178 +/- 0.031; RsaI, q(-) = 0.316 +/- 0.038; MspI, q(-) = 0.046 +/- 0.017. EcoRI turned out to be the most discriminant of the three polymorphisms because the frequency of the (+) allele in Sardinians was about half that estimated for a large homogeneous white sample (0.18 +/- 0.03 vs. 0.30 +/- 0.01). So far as the haplotype level is concerned, the sample is made up of triplets (parents and child). Therefore all the haplotype frequencies and delta values (degrees of disequilibrium, D) were obtained by direct counting of the unambiguously identified haplotypes rather than being based on their maximum-likelihood estimates. This together with their analytical and detailed presentation makes these data comparable with future findings, provided that the two data sets are presented in a comparable way. At this level the three RFLPs are efficient in distinguishing Sardinians from Calabrians (southern Italy) but not from the central Italian population. The present results, besides adding a further discriminative criterion between Sardinians and Italians (and whites on the whole), identify the complex COLIA2 locus as a valuable anthropogenetic marker.

[Arterial recanalization with the Kensey catheter. Preliminary results]

Fifteen patients with chronic obstruction of leg arteries (mean length: 6 cm) were treated with the Kensey catheter and then with PTA. In 11 cases the procedure was successful (74%) and in 2 it was interrupted--in one case for dissection and in the other for vessel perforation. Two maneuvers, after dissection, were ended with PTA and stent placement (overall success rate: 87%). Emergency surgery was never needed. In the cases solved with the Kensey catheter, the cumulative patency rate was 51% at 6, 12 and 24 months. The Kensey catheter did not improve the results of conventional PTA, which means its role is complementary to that of PTA and an alternative to more expensive laser systems, if PTA fails.

[Loco-regional thrombolysis in deep venous thrombosis]

Anticoagulation, by means of heparin and warfarin is, till now, the most common treatment in deep venous thrombosis. Although thrombolytic agents have been available for over 10 years, their use remains quite low, ranging from 15 to 20% of deep venous thromboses. This is due to the relatively high incidence of contraindications as well as to the fact that the potential advantages versus heparin are diminished by the increased bleeding risk and by the potential risk of pulmonary embolism (migration of partially lysed thrombi). Following the example of the "triple armed therapy" proposed by Rosenthal for the treatment of pulmonary embolism, we will evaluate if loco-regional thrombolysis, with the catheter wedged against the thrombus, associated with a temporary vena cava interruption by means of an intraluminal filter, can achieve a better lysis of the thrombus without pulmonary embolism. In our Unit 18 patients affected by proximal deep venous thrombosis were submitted to thrombolytic therapy, 6 to systemic treatment, 3 to local treatment and the last 9 to loco-regional thrombolysis, using recombinant tissue-type Plasminogen Activator. We obtained 10 complete lyses, 1 with systemic and 9 with loco-regional treatment. There were no major complications. Thus, we think that venous loco-regional thrombolysis with rt-PA at lower doses, associated with temporary caval interruption, can probably achieve a better lysis than systemic treatment without risk of pulmonary embolism and with a very low haemorrhagic risk, as in arterial loco-regional thrombolysis. Furthermore, loco-regional thrombolysis, by means of a faster thrombus dissolution, could better prevent post-phlebitic syndrome.

Percutaneous embolization of subclavian pseudoaneurysmatic arteriovenous iatrogenic fistula by steel coils

A case of iatrogenic subclavian arterio-venous fistula with pseudoaneurysm formation is described. Treatment by means of percutaneous embolization, on the venous side, with steel coils has been successful; in order to avoid complications, the arterial side was blocked by an angioplasty balloon. After discussing the more common complications of subclavian vein puncture, the Authors conclude that percutaneous embolization is a valuable alternative to surgery even in such a lesion, especially when the surgical risk is high.

Mechanisms of perturbation of erythrocyte calcium homeostasis in favism

Favism is an acute hemolytic anemia triggered by ingestion of fava beans in genetically susceptible subjects with severe deficiency of glucose-6-phosphate dehydrogenase (G6PD) activity. Erythrocytes from 10 favic patients had constantly and markedly increased calcium levels, as compared with values detected in 4 asymptomatic G6PD-deficient controls. Correspondingly, the calcium permeability of erythrocytes, estimated as the fraction of intracellular calcium exchangeable with externally added 45Ca2+, was invariably enhanced in favism and returned to normal patterns after several months from the acute hemolytic crisis. In favic patients, the levels of erythrocyte calcium ATPase activities showed wide variability, ranging from 2.0-12.9 mumol Pi/ml RBC/h, while control values in asymptomatic G6PD-deficient subjects were 10.62 +/- 2.03 mumol Pi/ml RBC/h. Analysis of the calcium ATPase in situ in erythrocyte membranes from favic patients showed the same molecular mass of 134 kD as observed in the control subjects. Exposure of G6PD-deficient erythrocytes in vitro to autoxidizing divicine, a pyrimidine aglycone strongly implicated in the pathogenesis of favism which leads to late accumulation of intracellular calcium, caused: (i) a marked inactivation of calcium ATPase, without changes in the molecular mass of 134 kD; and (ii) the concomitant loss of spectrin, band 3 and band 4.1, all known substrates of the calcium activated procalpain-calpain proteolytic system. Thus, the increased intraerythrocytic calcium apparently results in the degradation of calcium ATPase observed in some favic patients. It is proposed that both enhanced calcium permeability and a calcium-stimulated degradation of the calcium pump are the mechanisms responsible for the perturbation of erythrocyte calcium homeostasis in favism.

[Arterial embolism, venous thrombosis, pulmonary embolism: a suggestive triad]

The aim of this study is to present a relatively rare case of paradoxical arterial embolism, found in a patient who was sent to us for serious pulmonary embolism. Taking into account that the foramen ovale, despite being functionally competent, remains anatomically patent in 30% of the adult population, we cannot neglect the possibility of a paradoxical embolism, in the presence of a sudden embolic limb ischemia unless heart pathology or aortic lesions can be held responsible. Furthermore it must not be forgotten that deep venous thrombosis in the lower limbs or in the pelvic plexus may go unobserved on a purely clinical evaluation.

Molecular analysis of clonality in plasma cell dyscrasias

It has been suggested that multiple myeloma, generally considered a neoplastic disorder of mature plasma cells, may arise from a pluripotent haemopoietic stem cell. The possibility that circulating lymphocytes derive from the same neoplastic progenitor has been tested in a large number of studies in the past few years, as proof of the interest that this subject is raising among scientists, and also of its elusiveness. We studied a group of 29 patients with plasma cell dyscrasias in order to evaluate clonality of haemopoietic cell populations. The X-linked markers hypoxantine phosphoribosyltransferase (HPRT) and phosphoglycerate kinase (PGK) disclosed no monoclonal component in seven heterozygous women. Analysis of immunoglobulin gene rearrangement with four probes showed a germline configuration in samples from 25/29 patients. Only four bone marrow samples from subjects with aggressive disease had rearranged C mu sequence; one had rearrangement of JH and C mu.

Marked decline of favism after neonatal glucose-6-phosphate dehydrogenase screening and health education: the northern Sardinian experience

Favism is a potentially fatal manifestation of glucose-6-phosphate dehydrogenase (G6PD) deficiency, and it is therefore a public health problem in areas where this genetic abnormality is common. In the district of Sassari (northern Sardinia), the frequency of G6PD male hemizygotes is approximately 7.5%, and therefore all newborns since 1971 have been screened for G6PD deficiency. We have analyzed the incidence of favism in this community in two 10-year periods: (1) 1961-1970; and (2) 1981-1990. In period 1, there were 508 cases of favism, of which 76% occurred in boys. In period (2) there were 144 cases of favism, of which only 52% in boys. Thus, between the two periods there was an overall decrease in the incidence of favism of 75%, whereas the proportion of girls affected has approximately doubled. These data suggest that neonatal screening and health education programs can produce a substantial decrease in the number of cases of favism, and that the relative increase in favism in girls is possibly due to failure of the screening method used to detect all the heterozygotes for G6PD deficiency.

A further polymorphism of the Gd locus for glucose-6-phosphate dehydrogenase present among blacks (Nigerians) and apparently absent among Caucasoids: the quantitative isoelectrophoretic variation of the Gd+ allele

A structural but isoelectrophoretic moderate variation of glucose-6-phosphate dehydrogenase (G6PD) activity is common among Nigerians (a black population exposed to a long-lasting intense Plasmodium falciparum malarial endemia). It had never even been searched for among Caucasoids and Mongoloids. In the present work, we attempted to ascertain whether this polymorphism exists among Caucasoids. With this purpose, two Caucasoid male populations were studied: Sardinians and Romans, who respectively did and did not experience an evolutionarily effective exposure to P. falciparum. The approach adopted here consisted in comparing the variations of G6PD activity observed between brothers who certainly received their Gd gene from the same grandparent (hence Gd genes identical by descent) with those between brothers who received it (in the Roman series) or may have received it (in the Sardinian series) from different grandparents. No evidence for common moderate G6PD activity variations segregating with the Gd gene was found either in Romans or Sardinians, who have both been studied with much larger samples and more sensitive approaches than those which detected such type of polymorphism among Nigerians. The upper 95% confidence limit of such zero estimates for the frequency of the isoelectrophoretic quantitative Gd variant alleles were about 0.04 and 0.025 for Romans and Sardinians, respectively. This is the first example of a genetic region (the Gd gene with its flanking sequences) apparently monomorphic in a major race and with several (four) polymorphic sites in another major race.

Increased prevalence of glucose-6-phosphate dehydrogenase deficiency in patients with cholelithiasis

The glucose-6-phosphate dehydrogenase (G6PD) enzyme activity was determined in 299 Northern Sardinian patients with cholelithiasis. Sixteen (12.80%) of the 125 male patients studied were G6PD deficient; 33 (18.96%) of the 174 females were heterozygous and 1 (0.57%) homozygous. Thus, the prevalence of G6PD deficiency in male subjects with cholelithiasis is about 35% higher (p less than 0.02) than that of a normal male control group (7.29%). As regards female patients, the incidence of the GdMed allele was also significantly different (p less than 0.05). Thus, G6PD-deficient subjects may have a predisposition to develop gallstones, even in the absence of clinical signs of chronic hemolysis.

Glucose 6-phosphate dehydrogenase deficiency and cataract of patients in northern Sardinia

We determined the activity level of glucose 6-phosphate dehydrogenase in 467 patients with cataract from northern Sardinia. Of 226 men, 18 (8%) had glucose 6-phosphate dehydrogenase deficiency. Of 241 women, 30 (12%) were heterozygous and two (1%) were homozygous for glucose 6-phosphate dehydrogenase deficiency. These prevalences were not significantly different from those expected in the general population. We concluded that patients with glucose 6-phosphate dehydrogenase deficiency do not have a higher risk of developing cataract.

Aspirin-induced acute haemolytic anaemia in glucose-6-phosphate dehydrogenase-deficient children with systemic arthritis

In a 4-year 7-month-old boy with glucose-6-phosphate dehydrogenase deficiency and systemic arthritis a severe haemolytic anaemia occurred after the administration of acetylsalicylic acid. Erythrocyte fragmentation, with haemoglobin condensation zones next to clear zones, was observed on peripheral blood smears. Since viral or bacterial infections were excluded on the basis of the laboratory data, the anaemia was ascribed to aspirin.