Sleeve resection and prosthetic reconstruction of the pulmonary artery for lung cancer

BACKGROUND

Lobectomy associated with reconstruction of the pulmonary artery (PA) is a technically feasible alternative to pneumonectomy in patients with lung cancer. However, concern about postoperative complications and long-term survival limited its acceptance so far.

METHODS

Between 1989 and 1996, we performed a PA reconstruction in 52 patients (41 men, 11 women; age range 35 to 75 years, mean 60 years) with lung cancer. Eleven patients had induction chemotherapy. We performed 15 PA sleeve resections, 34 PA reconstructions by a pericardial patch, and three PA reconstructions by a pericardial conduit, associated with a bronchial sleeve lobectomy or bilobectomy (33), or with standard lobectomy (19). Immediate and long-term postoperative evaluation included spirometry, echocardiography, perfusion lung scans, computed tomography, and PA angiography. The follow-up ranged between 27 and 96 months and is complete for all patients.

RESULTS

We had one specific postoperative complication (PA thrombosis) and no mortality. Perfusion scans and PA angiography were normal in all but the 1 patient having thrombosis. Mean forced expiratory volume (FEV) in 1 s and forced vital capacity (FVC) were, respectively, 72% and 80% preoperatively, 65% and 76% 1 month after surgery, and then they plateaued at 70% and 78% after 6 months. Echocardiography showed patterns in the normal range and normal estimates of PA pressures in all but 2 patients. Five-year survival was 38.3% for the entire group, 18.6% for stages IIIA and B, and 64.4% for stages I and II.

CONCLUSIONS

Morbidity, mortality, and functional data do not differ from what is currently reported for standard lobectomy. Long-term survival is in line with that reported for standard resection. These data support PA reconstruction as a viable option in the treatment of lung cancer.

Functional alpha6-containing nicotinic receptors are present in chick retina

Despite the fact that the neuronal chick alpha6 subunit was first cloned several years ago and recently has been shown to form acetylcholine (ACh)-activated channels in heterologous systems, no information is yet available concerning the structure and function of the alpha6-containing nicotinic receptors in neuronal tissues. Using subunit-specific antibodies directed against two different epitopes of the chick alpha6 subunit, we performed immunoprecipitation experiments on immunopurified alpha6-containing receptors radiolabeled with the nicotinic agonist [3H]epibatidine (Epi): almost all of the alpha6 receptors contained the beta4 subunit, 51% the beta3 subunit, 42% the alpha3 subunit, and 7.5% the beta2 subunit. Western blot analyses of the purified receptors confirmed the presence of the alpha3, beta3, beta2, and beta4 subunits, and the absence of the alpha4, alpha5, and alpha7 subunits. The alpha6-containing receptors bind [3H]Epi (Kd = 35 pM) and a number of other nicotinic agonists with very high affinity, the rank order being Epi >> cytisine > nicotine > 1, 1-dimethyl-4-phenylpiperazinium > acetylcholine > carbamylcholine. The alpha6 receptors also have a distinct antagonist pharmacological profile with a rank order of potency of alpha-conotoxin MII > methyllycaconitine > dihydro-beta-erythroydine > MG624 > d-tubocurarine > decamethonium > hexamethonium. When reconstituted in lipid bilayers, the alpha6-containing receptors form functional cationic channels with a main conductance state of 48 pS. These channels are activated by nicotinic agonists in a dose-dependent manner, and blocked by the nicotinic antagonist d-tubocurarine.

Continuing drug therapy while breastfeeding. Part 2. Common misconceptions of physicians

QUESTION

Is there any way to predict whether a drug taken by a mother is safe for a suckling baby, or is it just trial and error? One of my patients is receiving lithium for manic depression. She wishes to breastfeed, but clinically there is no way she can discontinue the drug. My sources say the drug is incompatible with breastfeeding.

ANSWER

The amount of drug available to a baby through breastmilk is estimated as the percentage of maternal dose per kg ingested by the baby. Because infants' clearance rate of many drugs is slower than adults', however, the true level of the drug circulating in the infant's blood might be much higher. Because lithium can be measured in plasma, it is prudent to measure it in milk and to estimate the "baby dose." If a baby shows any adverse effects, lithium levels should be measured in its blood.

Clusterin (SGP-2) gene expression is cell cycle dependent in normal human dermal fibroblasts

In confluent human dermal fibroblasts brought to quiescence (G0) by serum starvation, the S phase peaked at 24 h after serum re-addiction and G2/M phase peaked at 36 h. This was confirmed by titration of h-gas1 mRNA (a marker of G0 phase) and histone H3 (a marker of S phase). Clusterin mRNA accumulation progressively increased in cells proceeding to confluence after seeding and to quiescence upon serum starvation, and peaked at around G0, in parallel with h-gas1 mRNA. At 6 h (roughly G1 phase) clusterin transcript formed a second peak, followed by a gradual decrease until 36 h. Correspondence of clusterin protein accumulation to its mRNA occurred solely with regard to the G0 peak but not to the second one. The possible meaning of the cell cycle related clusterin gene expression is discussed.

Selective effects of a 4-oxystilbene derivative on wild and mutant neuronal chick alpha7 nicotinic receptor

1. We assessed the pharmacological activity of triethyl-(beta-4-stilbenoxy-ethyl) ammonium (MG624), a drug that is active on neuronal nicotinic receptors (nicotinic AChR). Experiments on the major nicotinic AChR subtypes present in chick brain, showed that it inhibits the binding of [125I]-alphaBungarotoxin (alphaBgtx) to the alpha7 subtype, and that of [3H]-epibatidine (Epi) to the alpha4beta2 subtype, with Ki values of respectively 106 nM and 84 microM. 2. MG624 also inhibited ACh elicited currents (I(ACh)) in the oocyte-expressed alpha7 and alpha4beta2 chick subtypes with half-inhibitory concentrations (IC50) of respectively 109 nM and 3.2 microM. 3. When tested on muscle-type AChR, it inhibited [125I]-alphaBgtx binding with a Ki of 32 microM and ACh elicited currents (I(ACh)) in the oocyte-expressed alpha1beta1gammadelta chick subtype with an IC50 of 2.9 microM. 4. The interaction of MG624 with the alpha7 subtype was investigated using an alpha7 homomeric mutant receptor with a threonine-for-leucine 247 substitution (L247T alpha7). MG624 did not induce any current in oocytes expressing the wild type alpha7 receptor, but did induce large currents in the oocyte-expressed L247T alpha7 receptor. The MG624 elicited current (I(MG62)) has an EC50 of 0.2 nM and a Hill coefficient nH of 1.9, and is blocked by the nicotinic receptor antagonist methyllycaconitine (MLA). 5. These binding and electrophysiological studies show that MG624 is a potent antagonist of neuronal chick alpha7 nicotinic AChR, and becomes a competitive agonist following the mutation of the highly conserved leucine residue 247 located in the M2 channel domain.

Natural killer cell cytotoxicity and paternal lymphocyte immunization in women with recurrent spontaneous abortions

PROBLEM

Natural killer (NK)-cell cytotoxicity in women undergoing lymphocyte immunization prior to and following treatment was investigated.

METHOD OF STUDY

A cohort of 33 women with a history of two or more recurrent spontaneous abortions was prospectively studied. NK-cell cytotoxicity was determined at effector-to-target ratios of 50:1 and 25:1. Peripheral blood CD56+ NK-cell, CD19+ B-cell, CD19+/5+ B-1-cell, and CD3+ pan T-cell levels were studied by flow cytometry before and after lymphocyte immunization treatment. Maternal antipaternal T- and B-cell antibody levels were measured before and after lymphocyte immunization by flow cytometric analysis. Paternal lymphocyte immunizations were given two times with a 4-week interval. Post-lymphocyte immunization testing was done 4 weeks after the second lymphocyte immunization. The controls were 8 normal healthy women. NK assays were done twice with an interval of 8 weeks.

RESULTS

NK-cell activity at effector-to-target ratios of 50:1 (P = 0.005) and 25:1 (P = 0.001) were significantly suppressed after lymphocyte immunization. CD3+ pan T-cell levels after lymphocyte immunization were significantly increased compared with levels before lymphocyte immunization (P = 0.008). CD56+ NK-cell levels were significantly suppressed after lymphocyte immunization (P = 0.016). There was no correlation between changes in NK cytotoxicity and differences in antipaternal lymphocyte antibody levels before or after lymphocyte immunization.

CONCLUSION

Lymphocyte immunization suppresses NK-cell cytotoxicity and CD56+ NK-cell levels and increases the peripheral blood CD3+ T-cell population in women with recurrent spontaneous abortions.

In vitro genotoxic effects of the insecticide deltamethrin in human peripheral blood leukocytes: DNA damage ('comet' assay) in relation to the induction of sister-chromatid exchanges and micronuclei

Deltamethrin, a synthetic dibromo-pyrethroid insecticide, is extensively used in agriculture, forestry and in household products because of its high activity against a broad spectrum of insect pests (both adults and larvae), its low animal toxicity and its lack of persistence in the environment. Data on the genotoxicity and carcinogenicity of deltamethrin are rather controversial, depending on the genetic system or the assay used. The aim of this study was to further evaluate the potential genotoxic activity of deltamethrin. The in vitro genotoxicity of deltamethrin has been evaluated by assessing the ability of the insecticide to damage DNA (as evaluated using the single-cell microgel-electrophoresis or 'comet' assay) or induce sister-chromatid exchanges (SCE) and micronuclei (MN) in human peripheral blood leukocytes. All treatments were conducted with and without the presence of an external bioactivation source (+/- S9mix). The results indicate that deltamethrin, in the presence of metabolic activation (+ S9mix), is able to induce DNA damage (double- and single-strand breaks, alkali-labile sites and open excision repair sites) as revealed by the increasing tail moment values observed with increasing doses. The frequency of SCE and MN were not statistically increased in deltamethrin-treated cells as compared to controls, both with and without S9mix. However, lower deltamethrin doses were tested, as compared to 'comet' assay, because of cytotoxicity.

Radio-frequency thermal ablation of liver metastases with a cooled-tip electrode needle: results of a pilot clinical trial

The aim of this study was to evaluate feasibility, safety, and effectiveness of radio-frequency (RF) thermal ablation, performed by using a cooled-tip electrode needle, in the treatment of liver metastases. Twenty-nine patients (20 males and 9 females; age range 43-77 years) with one to four hepatic metastases 1.1-4.8 cm in diameter (mean 2.9 +/- 0.8 cm) from previously resected intra-abdominal primary malignancies were treated. All patients were excluded from surgery and had partial or no response to chemotherapy. Radio-frequency ablation was performed by using a 100-W generator and 17-gauge, dual-lumen, cooled-tip electrode needles with a 2- to 3-cm exposed tip. Exposure time was 12 min for each needle insertion. Findings at spiral CT were used to assess the therapeutic response. A total of 127 insertions were performed (mean 2.4 +/- 1.7 insertions/lesion) during 84 treatment sessions (mean 1.6 +/- 0.7 sessions/lesion) in absence of major complications. Complete tumor response (i. e., unenhancing area of thermal necrosis larger than the treated tumor) was seen in 41 (77 %) of 53 lesions, including 33 (87 %) of 38 lesions 3 cm or less in diameter. After a mean follow-up period of 6.5 +/- 2.1 months (range 3-9 months), recurrence of the treated lesion was seen in 5 (12 %) of the 41 cases. New metastatic lesions appeared in 7 patients. Two patients died after 6 and 8 months, respectively. Of the 27 patients still in follow-up, 14 are currently free of disease. Radio-frequency thermal ablation with a cooled-tip electrode needle is a safe and effective local treatment for hepatic metastases 3 cm or less in greatest dimension.

Predictive Value of History and Clinical Examination in Diagnosing Female Stress Incontinence

History, clinical examination, imaging and urodynamics are useful steps in diagnosing female stress urinary incontinence; there is however no single specific test for grading and staging incontinence. We studied 75 patients with stress urinary incontinence to evaluate the predictive value of history and clinical examination in diagnosis, compared to imaging and urodynamics. We considered parity, concurrent pathologies and therapies or surgery, 24-hour PAD-test, Q-tip test and pubo-coccigeal test versus translabial introital ultrasonography and urodynamics. Patients were divided into one group with cysto-rectocele and another without prolapse; we found no meaningful correlations except for 7 patients with sphincter damage. In the other women, history and clinical examination may only be helpful to choose proper diagnostic tools.

4-Oxystilbene compounds are selective ligands for neuronal nicotinic alphaBungarotoxin receptors

1. Starting from the structure of an old 4-oxystilbene derivate with ganglioplegic activity (MG624), we synthesized two further derivates (F2 and F3) and two stereoisomers of F3 (F3A and F3B), and studied their selective effect on neuronal nicotinic acetylcholine receptor (AChR) subtypes. 2. MG 624, F3, F3A and F3B inhibited of 125I-alphaBungarotoxin (alphaBgtx) binding to neuronal chick optic lobe (COL) membranes, with nM affinity, but inhibited 125I-alphaBgtx binding to TE671 cell-expressed muscle-type AChR only at much higher concentrations. 3. We immobilized the alpha7, beta2 and beta4 containing chick neuronal nicotinic AChR subtypes using anti-subunit specific antibodies. MG 624, F3, F3A and F3B inhibited 125I-alphaBgtx binding to the alpha7-containing receptors with nM affinity, but inhibited 3H-Epi binding to beta2-containing receptors only at very high concentrations (more than 35 microM); their affinity for the beta4-containing receptors was ten times more than for the beta2-containing subtype. 4. Both MG624 and F3 compounds inhibited the ACh evoked currents in homomeric oocyte-expressed chick alpha7 receptors with an IC50 of respectively 94 and 119 nM. 5. High doses of both MG 624 and F3 depressed the contractile response to vagus nerve stimulation in guinea pig nerve-stomach preparations although at different IC50s (49.4 vs 166.2 microM) The effect of MG624 on rat nerve-hemidiaphragm preparations was 33 times less potent than that of F3 (IC50 486 vs 14.5 microM). 6. In conclusion, MG624 and F3 have a high degree of antagonist selectivity for neuronal nicotinic alphaBgtx receptors containing the alpha7 subunit.

Pregnancy outcome following gestational exposure to fluoroquinolones: a multicenter prospective controlled study

Concerns regarding the teratogenicity of fluoroquinolones have resulted in their restricted use during gestation. This is despite an increasing need for their use due to emerging bacterial resistance. The objectives of the present investigation were to evaluate pregnancy and fetal outcomes following maternal exposure to fluoroquinolones and to examine whether in utero exposure to quinolones is associated with clinically significant musculoskeletal dysfunctions. We prospectively enrolled and followed up 200 women exposed to fluoroquinolones (norfloxacin, ciprofloxacin, ofloxacin) during gestation. Pregnancy outcome was compared with that for 200 controls matched for age and for smoking and alcohol consumption habits. Controls were exposed to nonteratogenic, nonembryotoxic antimicrobial agents matched by indication, duration of therapy (+/- 3 days), and trimester of exposure. Rates of major congenital malformations did not differ between the group exposed to quinolones in the first trimester (2.2%) and the control group (2.6%) (relative risk, 0.85; 95% confidence interval, 0.21 to 3.49). Women treated with quinolones had a tendency for an increased rate of therapeutic abortions compared with the rate among women exposed to nonteratogens (relative risk, 4.50; 95% confidence interval, 0.98 to 20.57), resulting in lower live-birth rates (86 versus 94%; P = 0.02). The rates of spontaneous abortions, fetal distress, and prematurity and the birth weight did not differ between the groups. Gross motor developmental milestone achievements did not differ between the children of the mothers in the two groups. We concluded that the use of fluoroquinolones during embryogenesis is not associated with an increased risk of major malformations. There were no clinically significant musculoskeletal dysfunctions in children exposed to fluoroquinolones in utero. The higher rate of therapeutic abortions observed in quinolone-exposed women compared to that for their controls may be secondary to the misperception of a major risk related to quinolone use during pregnancy.

Combined transcatheter arterial chemoembolization and percutaneous ethanol injection for the treatment of large hepatocellular carcinoma: local therapeutic effect and long-term survival rate

The aim of our study was to investigate local therapeutic effects and long-term results of combined transcatheter arterial chemoembolization (TACE) and percutaneous ethanol injection (PEI) in the treatment of large hepatocellular carcinoma (HCC). Eight-six patients (67 males and 19 females, age range 48-75 years, mean age 65.1 years) with Child-Pugh class A (n = 48) or B (n = 38) liver cirrhosis and a large HCC (main tumor 3.1-8 cm in diameter with no more than two daughter nodules) were enrolled in a prospective study. All patients underwent a single TACE session followed by PEI. Follow-up ranged from 4 to 65 months (mean 27.8 months, median 26 months). No major complication occurred. The local therapeutic effect, as assessed on the basis of findings at CT and MR imaging, was complete response in 71 of 86 patients (82 %) and partial response in 15 of 86. Overall survival rates by the Kaplan-Meier method were 92 % at 1 year, 83 % at 2 years, 69 % at 3 years, 58 % at 4 years, and 47 % at 5 years. Survival of Child-Pugh A patients (75 % at 3 years and 59 % at 5 years) was significantly longer (p < 0.01) than that of Child-Pugh B patients (61 % at 3 years and 35 % at 5 years). Combined TACE and PEI is an effective treatment for large HCC.

Detection of DNA damage in stressed trout nucleated erythrocytes using the comet assay: protection by nitroxide radicals

Because previous literature reports have demonstrated that nucleated trout erythrocytes in conditions of oxidative stress are subjected to both membrane damage and a decrease in the enzymatic defense systems (glutathione peroxidase), which in turn lead to hemolysis, the present study was undertaken to determine whether DNA may be affected too, prior to the hemolytic event. Impairment of DNA in stressed trout erythrocytes was assessed using the comet assay--a rapid and sensitive, single-cell gel electrophoresis technique used to detect primary DNA damage in individual cells. In addition, indolinic and quinolinic nitroxide radicals were included in the study to determine their efficacy as antioxidants against free-radical-induced DNA damage. The parameters, tail length, tail intensity, and tail moment, used as an index of DNA damage, have shown that trout erythrocytes exposed to oxidative stress experience DNA damage prior to hemolysis and that the nitroxides significantly prevent this damage. This result provides further information about the potential use of these compounds as antioxidants in biological systems.

Extent of DNA damage in density-separated trout erythrocytes assessed by the 'comet' assay

The 'comet' assay is being increasingly employed for evaluating DNA damage in biological systems. Using this technique, we examined DNA damage in whole in density-separated trout erythrocytes. Results clearly show that all the three considered parameters (tail length, tail intensity and tail moment) increased with the density of the fractions, possibly reflecting different degrees of DNA damage. Probably, this behaviour is due to different periods of exposure of the density fractions to the hazard of active oxygen radicals; older cells have been exposed to oxidative stress for a longer time.

Differentiation of hepatocellular adenoma and focal nodular hyperplasia of the liver: comparison of power Doppler imaging and conventional color Doppler sonography

The aim of our study was to compare the diagnostic efficacy of power Doppler imaging and conventional color Doppler sonography for differentiating between hepatocellular adenoma (HCA) and focal nodular hyperplasia (FNH) of the liver. Thirty-one focal liver lesions (in 29 patients) with histologic proof of HCA (n = 9) or FNH (n = 22) were studied with power and color Doppler sonography according to a standardized examination protocol. The size of the lesions ranged between 1.5 and 14.5 cm (HCA, 3.5-14.5 cm, mean +/- SD 7.3 +/- 3.3 cm; FNH, 1.5-9.1 cm, mean +/- SD 5.1 +/- 2.1 cm). Intratumoral vessels with a venous Doppler spectrum, associated with either pulsatile or continuous peripheral flow, were detected in HCA (eight of nine lesions by power Doppler imaging and six of nine by color Doppler imaging) but not in FNH. In contrast, color signals with an arterial Doppler spectrum, radiating from the center to the periphery of the lesion, were depicted in FNH (20 of 22 cases by power Doppler imaging and 15 of 22 by color Doppler sonography) but not in HCA. Differentiation of HCA and FNH was achieved in 28 of 31 cases (90 %) by power Doppler imaging and in 21 of 31 (68 %) by color Doppler sonography (p < 0.01). Power Doppler imaging is superior to conventional color Doppler sonography in the depiction of the intratumoral flow characteristics of HCA and FNH, and enables a more accurate differential diagnosis than color Doppler sonography.

Mutagenicity and clastogenicity of gas stove emissions in bacterial and plant tests

The aim of this research was to study the gaseous and particulate emissions of genotoxic substances during cooking with two types of methane stoves (a new one and an old one). The particulates were sampled both with a cascade impactor air sampler and an impinger with ice trap and analyzed by two bacterial mutagenicity tests (Ames and Kado tests) and by HPLC for polycyclic aromatic hydrocarbons (PAH). Gaseous emissions were studied in situ using the Ames test, a clastogenicity plant test (Tradescantia-micronucleus test), and in an automated system for chemical analyses. Clear indirect mutagenicity was found only with the Kado test (TA98-S9) in extracts of particulates emitted from the old methane stove and collected with the impinger. Similar mutagenicity (TA98+S9) was also found for the finest fraction of particulates (<0.5 um) collected from both stoves. Gaseous emissions of both stoves caused clastogenicity in the in situ experiments with the Tradescantia-micronucleus test. The physico-chemical analyses of the emissions showed also the presence of very fine particulates and trace amounts of PAH. The exposure of these genotoxins could be particularly important for occupationally exposed individuals in homes and businesses and for susceptible subjects living indoors for long periods (infants, children, the sick, and the elderly).

Lansoprazole and ethanol metabolism: comparison with omeprazole and cimetidine

Since some antisecretory drugs such as cimetidine and ranitidine, interfere with ethanol metabolism by inhibition of hepatic and/or gastric alcohol dehydrogenase, we investigated the effect of lansoprazole, a new protonic pump inhibitor, on gastric and hepatic alcohol dehydrogenase activity. We also compared the lansoprazole effect with that of omeprazole and cimetidine, respectively. Ethanol blood concentration after oral intake or intravenous administration of ethanol was estimated either in normal male human volunteers or in male rats before and after one week pretreatment with lansoprazole, omeprazole and cimetidine. Furthermore, the in vitro effect of these drugs was studied on both human and rat gastric and hepatic alcohol dehydrogenases. Finally, we measured the effect of the treatment on the reduced hepatic glutathione to test the effects of the drugs on first-pass metabolism of ethanol. The results reported in this paper indicate that lansoprazole, as well as omeprazole, does not affect ethanol metabolism, and that protonic pump inhibitors seem to be safer than imidazole-derived drugs in subjects unable to reduce ethanol intake during conditions requiring acid secretion inhibition.

Applicability of aspecific noninvasive methods for biomonitoring of occupational exposure to deltamethrin: preliminary study using an animal model

Deltamethrin (CAS registry No. 52918-63-5), a synthetic dibromo-pyrethroid insecticide is highly effective against a broad spectrum of insects, and is widely used on crops and in public health programs. Data on the genotoxicity and carcinogenicity of deltamethrin are rather controversial, depending on the genetic system or the assay used. The aim of the present study was to analyze previously demonstrated metabolic changes using aspecific noninvasive methods in rats which are potentially applicable for monitoring occupational exposure. Since human exposure to pesticides occurs not only to active principles but to all chemicals present in a commercial formulation, we tested both the pure compound and a deltamethrin-based commercial formulation. Groups of rats were treated, i.p., consecutively for 7 days. The daily doses tested were 5 and 10 mg/kg body weight for pure deltamethrin, corresponding to volumes of 178.57 and 377.14 microliter/kg body weight for the commercial formulation (containing 2.8% deltamethrin). Urine was analyzed for mutagenic metabolites, thioethers, and D-glucaric acid content. Faeces extracts were tested for mutagenicity. Results show that DGA urinary excretion values did not mirror the phase I enzyme induction capability of the insecticide. Results obtained for urinary thioethers do not agree completely with those obtained on the influence of deltamethrin on glutathione S-transferase activity in rat liver. In fact, after administration of the deltamethrin commercial formulation, highest thioether excretion values were obtained during the treatment time for treated animals, as compared to controls. The mean values (+/-SEM) of thioether excretion were 0. 033 +/- 0.002 micromole -SH/24 h for control animals, 0.122 +/- 0. 004 and 0.185 +/- 0.025 for the two treatment groups. Thence, thioether determination in urine samples seems to be a suitable aspecific noninvasive method for assessing exposure to deltamethrin-based formulations, particularly those containing xylene and mesitylene as solvents, as in the tested formulation. Negative or toxic results obtained in the urinary and faecal mutagenicity test seem to exclude the formation and excretion of mutagenic metabolites following treatment with deltamethrin.

Submicroscopic mathematical evaluation of spermatozoa in assisted reproduction. 4. The bovine fertilization (Notulae seminologicae 10)

In this paper we apply a modification of the formula of Baccetti et al. (1995) in the evaluation of submicroscopical characteristics of bull spermatozoa used in assisted reproduction. In the present experiment sperm quality is proposed as a useful parameter in predicting the success of fertilization. Our results demonstrate that the percentage of spermatozoa devoid of submicroscopic defects, according to the particular Bayesan formula proposed by us, is clearly correlated with the result of artificial insemination. In fact, the parameter concerning sperm quality obtained in variously successful donors shows a large correlation with fertility power. The synthetic parameters observed are therefore a good tool in the prediction of sperm power in artificial fertilization. The evaluation is mainly concerned with the quality of the acrosomal characters, the status of the chromatin, the shape of mitochondria, the position of the postacrosomal sheath, the perinuclear space and the axonemal pattern. All these characters are expressed with different means in ejaculates. All these data confirm that submicroscopic-mathematical evaluation offers a convincing and reliable diagnosis based upon sperm structure and functions such as acrosomal reaction and cell motility. It has been also demonstrated that sperm quality is a major factor in the success of artificial insemination and it is clearly revealed in the integrity of most of sperm organelles.

Comparison of the diagnostic performance of high-frequency ultrasound as a first- or second-line diagnostic tool in non-palpable lesions of the breast

To compare the diagnostic performance of high-frequency ultrasound (HFU) as a first- or second-line diagnostic tool in non-palpable lesions (NPL) of the breast and to define the place of HFU in the diagnostic process, 89 women with this kind of lesion, previously detected by mammography, underwent HFU with 7.5-13 MHz transducers. The examinations were performed by two equally experienced operators of which only one (operator I) was aware of the mammographic findings. The mammographic examinations revealed the following non-palpable lesions: asymmetry-hyperdensity (17 cases), nodule (44 cases), stellate lesion (5 cases), microcalcifications (23 cases). Total sensitivity of HFU in the examinations performed by operator I was 83 %, while in the examinations performed by operator II (unaware of the mammographic findings) it was only 35 %. In all cases HFU allowed the operators to determine the basic features of the lesions. Our experience confirms that ultrasonography, even if performed with high frequency, cannot be proposed as a screening examination but may profitably be employed as a second-step technique to characterize NPL previously identified by mammography. This 'second-step' role can do the following: rule out true pathology (cases of false-positive mammography findings); furnish some basic features in the case of focal lesions; show other findings in the case of microcalcifications, such as microcysts, 'filled duct' appearance, parenchymal inhomogeneities and nodules; guide interventional procedures; and localize lesions preoperatively.

[The correct mammographic exam: the usefulness of additional views]

INTRODUCTION

Till 20 years ago, physical examination of the breast was the fundamental procedure for the diagnosis of breast conditions, but mammography has now become the only examination to diagnose infraclinical carcinoma. High quality mammographic images enhance the radiologist's skill.

MATERIAL AND METHODS

We performed 2713 mammograms in a year's work and then selected 456 patients with questionable or poor mammographic findings (craniocaudal or midlateral oblique views) for further studies. The additional examinations were performed either to show the whole gland or to clarify the following findings: hyperdensity/asymmetry, ill defined nodule/pseudonodule, stellate lesions, microcalcifications, superficial or cutaneous lesions, inflexed nipples. As additional studies, we acquired spot compression images with/without magnification, exaggerated craniocaudal and cleavage images, images with a skin marker, rolled and tangential images. Based on radiologic findings, 155 patients were submitted to US, 104 to FNAB (under US or stereotaxic guidance) and 67 to surgery.

RESULTS

The additional views proved useful in 83.2% of patients showing the whole parenchyma in 35.4%, ruling out suspected abnormalities in 28.8%, depicting and characterizing nodules and microcalcifications in 19% of patients.

CONCLUSIONS

In our study, additional views played an important role in the correct execution of mammographic studies because they: showed the whole gland; permitted to rule out suspected pathologic conditions; confirmed and defined previous questionable lesions, thus allowing the radiologist to plan the proper diagnostic route.

Detection of antibody classes and subpopulations in myasthenia gravis patients using a new nonradioactive enzyme immunoassay

To investigate the presence of antibodies in myasthenia gravis (MG) patients, we have developed a new reproducible and sensitive enzyme immunoassay (EIA-AChR), in which a beta subunit-specific monoclonal antibody (mAb 73) immobilizes fetal calf acetylcholine receptors (AChRs). We tested 92 MG patients (42 with positive and 50 with negative antibody titers), 60 healthy controls, and 40 controls with other autoimmune diseases. EIA-AChR detected immunoglobulin G (IgG) titers in all of the seropositive samples, with a significant correlation between these and those obtained using the traditional immunoprecipitation method. Moreover, 5 seronegative patients at immunoprecipitation assay were positive at EIA-AChR. EIA-AChR was also useful in revealing: (1) a seropositive patient subpopulation with generalized MG who had Abs directed against alpha-Bungarotoxin binding sites; and (2) patients with IgM directed against fetal calf AChR (detected in 13 seronegative and 16 seropositive MG patients, and in 6 of the patients with other autoimmune diseases).

Alpha7 and alpha8 nicotinic receptor subtypes immunopurified from chick retina have different immunological, pharmacological and functional properties

Nicotinic receptors are present in the chick retina, but their structure and functional characteristics are still unclear. Using anti-alpha7 and anti-alpha8 subunit-specific antibodies, we immunopurified the alpha7 and alpha8 subtypes of chick retina neuronal nicotinic receptors. When analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis, the two purified subtypes consistently showed a similar peptide composition characterized by the presence of two major peptides of M(r) 58 +/- 1 and 54 +/- 1 kDa, and two minor peptides of 67 and 61 +/- 1 kDa. In the alpha7 subtype, the 58 kDa peptide was recognized by anti-alpha7 but not by anti-alpha8 antibodies; in the alpha8 subtype, the 58 kDa peptide was recognized only by anti-alpha8 antibodies. The alpha7 subtype had a single class of [125I]alpha-bungarotoxin binding sites with a K(D) value of 1.2 nM, whereas the purified alpha8 subtype had two classes of binding sites, one with a K(D) of 5.5 nM and the other with very high affinity (KD 52 pM), but present in only 8% of the receptors. Competition binding experiments also showed the presence on the alpha8 subtype of high- and low-affinity classes of binding sites; the affinity for cholinergic drugs of the former was greater than that of the single class present on the alpha7 subtype. When reconstituted in planar lipid bilayers, both subtypes formed ligand-gated cation channels with major conductance levels of 42 and 52 pS but with different lifetimes; the two channels were activated by agonists and blocked by d-tubocurarine and the glycinergic antagonist strychnine. In line with the binding data, the reconstituted alpha8 subtype had greater agonist sensitivity than the alpha7 subtype.