The ameloblast movement in rat incisor. L.M., S.E.M. and C.L.S.M. study

The internal epithelium of enamel organ and the below enamel surface during growth of the lower incisor, were examinated in ten Wistar rat 12-27 weeks old and weighing between 150/200 gr, by means of immuno histochemical, light and scanning electron microscopy techniques. Our specimens indicate that during the outer enamel secretion the anti-actin positivity goes from distal terminal web to infra nuclear region of cell body. The results of the present study do not support the active movement hypothesis, conversely they support the Warshawsky (1992) hypothesis, i.e. the distal terminal web permits the maintenance and the assembling of ameloblasts during enamel growth. Hence we do agree with Osborn (1970) who reported that, during secretion, ameloblasts move passively in response to secretory forces.

Short-term clinical outcome of patients with acute pulmonary embolism, normal blood pressure, and echocardiographic right ventricular dysfunction

BACKGROUND

The role of echocardiographic right ventricular (RV) dysfunction in predicting clinical outcome in clinically stable patients with pulmonary embolism (PE) is undefined. In this study, we assessed the prevalence and clinical outcome of normotensive patients with RV dysfunction among a broad spectrum of PE patients.

METHODS AND RESULTS

This prospective clinical outcome study included cohort of 209 consecutive patients (age, 65+/-15 years) with documented PE. Acute RV dysfunction was diagnosed in the presence of >/=1 of the following: RV dilatation (without hypertrophy), paradox septal systolic motion, and Doppler evidence of pulmonary hypertension. Four groups were identified: 28 patients presenting with shock or cardiac arrest (13%), 19 hypotensive patients without shock (9%), 65 normotensive patients with echocardiographic RV dysfunction (31%), and 97 normotensive patients without RV dysfunction (47%). Among normotensive patients with RV dysfunction, 6 (10%) developed PE-related shock after admission: 3 of these patients died, and 3 were successfully treated with thrombolytic agents. In comparison, none of the 97 normotensive patients without RV dysfunction developed shock or died as a result of PE.

CONCLUSIONS

A significant proportion (31%) of normotensive patients with acute PE presents with RV dysfunction; these patients with latent hemodynamic impairment have a 10% rate of PE-related shock and 5% in-hospital mortality and may require aggressive therapeutic strategies. Conversely, normotensive patients without echocardiographic RV dysfunction have a benign short-term prognosis. Thus, early detection of echocardiographic RV dysfunction is of major importance in the risk stratification of normotensive patients with acute PE.

Treatment of pulmonary artery stenosis after arterial switch operation: stent implantation vs. balloon angioplasty

The development of pulmonary artery stenosis is a potential complication during the mid- to long-term follow-up after arterial switch operation (ASO) for transposition of the great arteries. Surgical results have been disappointing and conventional balloon dilation yields a fairly important incidence of failures and recurrences. We evaluated our results with implantation of balloon-expandable stents in 5 out of 13 patients with a previously attempted unsuccessful conventional balloon dilation of pulmonary artery branch stenosis after ASO. In two more cases, stents were used as a primary procedure. Balloon angioplasty achieved a 15% increase in mean diameter of the stenosis vs. 124% with the use of stents (P< 0.01), a 10% decrease of the pressure gradient across the stenosis vs. 71% of stents (P<0.01), and a 10% drop in RV/aorta pressure ratio vs. 43% of stents (P<0.01). Compared to conventional balloon angioplasty in our series, stents were more effective in the treatment of patients with peripheral pulmonary artery stenosis after ASO. Balloon dilation should be considered in selected cases unsuitable for treatment with endovascular stents.

Immunofluorescence distribution of actin-associated proteins in human seminiferous tubules of adolescent testes, normal and pathologic

The aim of our study on human seminiferous tubules of adolescent testes was to study the localization of two actin-associated proteins of the adherens junctions, such as vinculin and talin, and to verify if there were modifications in their pattern in varicocele, a frequent disease of the testis in adolescent age. The study group consisted of 8 biopsies from normal testes (i.e., adolescents operated on for hydrocele or inguinal hernia) and 20 biopsies from pathological testes (i.e., adolescents operated on for idiophatic left varicocele). Biopsies were evaluated by indirect immunofluorescence using anti-human vinculin and anti-human talin antibodies. Observation was recorded with a Leica TCS 4D upright confocal microscope. In the normal testes, there was a strong positive immunoreactivity for vinculin, which was localized in the interstitial cells of Leydig, and both basal pole and lateral cell surface of Sertoli cells; the pattern of talin immunoreactivity was the same except that the lateral cell surface of Sertoli cells was not stained. In the varicocele group the pattern was different. Vinculin immunoreactivity showed small patches of fluorescence only in the cytoplasm of Sertoli cells while talin immunoreactivity showed a scanty distribution at the basal surface of Sertoli cells. These results confirm that, similarly to other tissues, vinculin is expressed at cell-cell and cell-matrix adherens junctions, while talin is present at cell-matrix adherens junctions in human seminiferous tubules of normal adolescents. Varicocele alters the patterns of these two proteins both quantitatively and qualitatively.

Ultrastructural and immunohistochemical study of basal lamina of the testis in adolescent varicocele

OBJECTIVE

To evaluate a possible involvement of the extracellular matrix (ECM) in the testes of adolescents with varicocele.

DESIGN

Cross-sectional study.

SETTING

University-based medical center.

PATIENT(S)

Twenty-four adolescents aged between 13 and 18 years underwent surgical treatment for repair of left idiopathic varicocele.

INTERVENTION

A testis biopsy was performed at time of surgery.

MAIN OUTCOME MEASURE(S)

Transmission electron microscopy study of basal lamina and immunofluorescence studies of collagen type IV and laminin, two major components of basal lamina.

RESULT(S)

Transmission electron microscopy observations showed an uneven profile of the basal lamina with a variable thickness. Immunofluorescence studies showed an irregular immunofluorescent line that appeared interrupted in some observations. Collagen type IV showed some areas of strong immunostaining with other areas with reduced immunoreactivity.

CONCLUSION(S)

Our ultrastructural and immunohistochemical observations highlight focal damage at the level of peritubular basal lamina, but this damage is not as severe as that described in adult varicocele. Initial involvement of basal lamina could represent one of the mechanisms responsible for varicocele-induced histologic alterations of the testes.

[Diabetic foot. Physiopathology, clinical aspects, and recent therapeutic approaches]

Diabetic foot is a complication of diabetes mellitus occurring in 15% of patients that is of specific surgical interest. Over the past few years, preventive measures and the use of new therapeutic resources has reduced the number of patients undergoing demolitive surgery. The authors present a concise but at the same time sufficiently detailed picture of modern knowledge of the physiopathology, clinical aspects and current therapeutic guidelines for diabetic foot. In particular, they analyse the validity of various forms of complementary treatment to surgery, including techniques to stimulate tissue repair processes, hyperbaric oxygen therapy and laser therapy, and they underline the importance of using a multidisciplinary approach to this pathology. To this end, they review all the articles on the subject reported on Medline from 1992 to June 1998, presenting and commenting on the most significant results.

[Axillary lymphadenectomy and its complications]

Local and regional complications of axillary dissection are evaluated. According to other authors, the most frequent ones are infections, seroma and lymphoedema. Sentinel node biopsy can reduce the number of dissections and their complications.

Critical left ventricular outflow tract obstruction due to accessory mitral valve tissue

Left ventricular outflow tract (LVOT) obstruction due to anomalous tissue tag arising from the mitral valve is a rare congenital cardiac anomaly. It generally becomes symptomatic during the first decade of life as exercise intolerance, chest pain, or syncope at effort. To date, only a few cases of critical systemic obstruction due to isolated mitral valve anomaly in neonates have been reported. We report the case of a neonate who was a few hours old and was referred in severe clinical condition due to critical left ventricular outflow obstruction resulting from an anomalous tissue tag of mitral valve origin.

Myofibroblasts in adolescent varicocele: an ultrastructural and immunohistochemical study

Myofibroblasts of the testes play an important role in the morphofunctional integrity of the seminiferous tubule. Previous studies in adults with varicocele have demonstrated an involvement of this cell population that tends to transform into fibroblasts. The aim of the present study was to try and verify the morphological features of myofibroblasts in the adolescent with left idiophatic varicocele. Twenty-two testicular biopsies were obtained from adolescents (aged 13-18 years, mean 15.8) and operated for left idiophatic varicocele. Biopsies were processed for electron microscopy (TEM) and immunofluorescence studies. The latter determined the level of myofibroblasts by using alpha-smooth muscle isoactin, a specific marker of myofibroblasts and, hence, excluding fibroblasts. TEM observations revealed a normal ultrastructure of myofibroblasts that was similar to that for the controls but an increased presence of extracellular matrix. The immunofluorescence study always demonstrated strong cell positivity to anti alpha-smooth muscle isoactin as also seen in the controls. This study demonstrates that adolescents with varicocele have well preserved myofibroblasts and do not show any evidence of transformation into fibroblasts, this has already been demonstrated in adult varicocele. These observations could represent an important factor for the understanding of the reversal of growth failure of the testes observed after early treatment.

Ameloblast morphogenesis during amelogenesis. S.E.M. study

A study has been carried out on the S.E.M. on the enamel of an albino rat's inferior incisor. The observations concern almost the entire ameloblastic cycle, specifically, from the end of the cellular differentiation phase (pre-ameloblasts III) to the end of the modulation phase. The authors have pointed out some morphogenetical variations which during the depositing phase, are manifested on the distal extremity of the cells and are concentrated at this level in the differentiation of the Tomes' processes. Successively, during the transitional post-secretory and cellular modulation phases, the morphogenetical differences at the distal extremities also involve the lateral walls of the ameloblasts and their spatial relationships. Some morphological differences are correlated with different functional moments and revealed by an examination of the corresponding superficial areas of the enamel in the course of its formation. In this study, the constant orientation of the perpendicular is evident at the secretion plane in opposition with other studies that propose a 'pendulum movement' theory of these cells during the depositing phase of the prismatic layers. In addition, a morphological classification is proposed consisting of four types of modulative ameloblasts.

[Buschke and Loewenstein tumors (giant condyloma acuminata). Immunologic features]

The Buschke-Loewenstein tumor, also called giant condyloma acuminatum, is generally observed in male subjects, usually on the penis and rarely occurs in women. A case of Buschke-Loewenstein tumor located on the vulva is reported. It is a cauliflower-like tumor which behaves clinically in a malignant fashion, although it shows no histomorphological criteria of malignancy. Histologically it is a benign papillomatous growth characterized predominantly by epithelial hyperplasia, hyperacanthosis and hyperkeratosis. The assessment of humoral and cellular immunity demonstrated an unusual circulating increase of CD4+ lymphocytes suggesting their major role in the very slow progression of the disease. Surgery remains the treatment of choice for this tumor.

[Should the patient with an interatrial defect recognized in adulthood always be operated on?]

BACKGROUND

Atrial septal defect (ASD) can be recognized in adult age, mostly in asymptomatic or scarcely symptomatic patients. These patients differ from patients in "historical" clinical series, in whom diagnosis was done on the basis of clinical evidence, and their natural history is probably different.

AIM OF THE STUDY

Our aim was to verify retrospectively results of surgery versus medical follow-up in an adult population with ASD with age at first diagnosis > or = 30 years.

PATIENTS AND METHODS

Seventy-two patients with ASD, 52 females (72%), observed at our Institution since 1978, were considered. Mean age at diagnosis was 48 +/- 12 years (range 30-79); 36 patients (50%, group A) are still on medical therapy, 36 patients (group B) were operated. As groups A and B did not differ significantly in any demographic, clinical or echocardiographic parameter, they were compared for the incidence of complications.

RESULTS

During follow-up (100 +/- 70 months, range 12-240), the incidence of major clinical events showed no significant differences in the two groups, as cardiac death or cardiovascular complications (cerebral ischemic events, severe mitral insufficiency, reoperation) occurred in 4 patients in group A (11%) and in 4 patients in group B (11%). Worsening of NYHA class was observed in 3 patients from group A (8%) and 2 patients from group B (5.5%; p = ns). New onset of supraventricular arrhythmias occurred more frequently in group B (14 patients, 39%) than in group A (5 patients, 14%) (p = 0.01; OR = 3.9; CI 95%: 1.2-12.6).

CONCLUSIONS

In an adult population affected with asymptomatic or mildly symptomatic ASD and age at first diagnosis > or = 30 years, surgical closure of the defect did not modify morbidity and mortality at a mid-term follow-up. We suggest that, mostly in older asymptomatic patients, surgery should not be a routine choice and clinical decision-making should be individualized in each case.

[Local recurrence of breast cancer]

The Authors analyse the prognostic value of the breast cancer local recurrence which not influence survival. For this reason the surgical treatment sometime can be conservative like the first treatment.

The dermoepidermal junction in psoriatic skin as revealed by scanning electron microscopy

Our previous ultrastructural and immunohistochemical studies, in vivo and in vitro, have shown important modifications of the basement membrane of psoriatic skin, which could play a key role in the alterations of keratinocyte adhesion, migration, proliferation and differentiation. In order to complete the morphological examination of all the structures in the dermoepidermal junction of psoriatic skin, we carried out a scanning electron microscopic study using biopsies taken from eight psoriatic patients. The biopsies were fixed in a mixture of 0.2% paraformaldehyde and 0.25% glutaraldehyde in 0.1 M cacodylate buffer at pH 7.4. The specimens were then frozen in liquid nitrogen and fractured following the natural cleavage planes and observed under a Jeol JSM-6301F field emission scanning electron microscope operating at 1.8-2.0 kV. The basal keratinocytes observed showed pore-like depressions on the lateral plasmalemma and villous-like projections in very dilated intercellular spaces. Moreover the basal cell plasma membrane was seen to rest on the papillary dermis without interposition of the lamina densa. The detachment of some keratinocytes enabled the examination of the lamina densa, which appeared slightly granular with numerous focal interruptions through which it was possible to observe the underlying collagen fibres. These findings, together with previously reported findings, support the hypothesis that in psoriasis molecular and structural alterations of the dermoepidermal junction are present, that could fundamentally alter the regulation of the cytomorphological processes and the normal functions of the basement membrane.

Repeat syncopal attacks due to postsurgical right ventricular pseudoaneurysm

Pseudoaneurysm of the right ventricular outflow tract is a rare lesion caused by disruption of the ventricular wall that allows the blood to leak into the surrounding space. It often complicates surgery involving right ventriculotomy and progressively increases in size, therefore causing airway compression, pulmonary perfusion asymmetry, thromboembolism, and rupture. We report on a patient who developed right ventricular pseudoaneurysm early after surgery for atrio-ventricular septal defect with tetralogy of Fallot and needed emergency surgical repair due to low cardiac output and repeat syncopal attacks.

Echocardiographic diagnosis of totally anomalous pulmonary venous connection to the azygos vein

Totally anomalous pulmonary venous connection to the azygos vein is a rare congenital heart malformation in which all the pulmonary venous blood returns anomalously to the azygos vein. Among 111 consecutive patients with totally anomalous pulmonary venous connection undergoing surgical correction at our institution between June 1982 and September 1997, this malformation was present in seven cases. By echocardiography, using a subxyphoid short-axis view at the atrial level and a modified suprasternal sagittal view, the malformation was diagnosed when the pulmonary venous confluence was traced posteriorly and superiorly relative to the right pulmonary artery and right bronchus, finally reaching reach the superior caval vein. Totally anomalous pulmonary venous connection to the azygos vein was misdiagnosed in the first two patients, both by echocardiography and angiocardiography. In the subsequent five patients, a precise diagnosis was obtained by echocardiography. Echocardiography, therefore, can be considered an accurate diagnostic tool permitting recognition of totally anomalous pulmonary venous connection to the azygos vein, and permitting corrective surgery without recourse to catheterization and angiography.

A morphometric and ultrastructural study of the changes in the lamina propria in adolescents with varicocele

OBJECTIVE

To verify if changes in the lamina propria and its components, reported in adults with varicocele, are already present in adolescents with idiopathic varicocele, using a morphometric and ultrastructural study.

MATERIALS AND METHODS

Twenty testicular biopsies from adolescents (mean age 15.6 years) were obtained during surgery for left idiopathic varicocele; five testicular biopsies from adolescents (mean age 16 years) undergoing surgery for hydrocele or inguinal hernia were used as controls. Biopsy specimens were processed for light and transmission electron microscopy; the sections were evaluated morphometrically using computerized image analysis.

RESULTS

Morphometric and ultrastructural examination of the testes with varicocele showed an increased thickness in the lamina propria, caused principally by an increase in the extracellular matrix components, and deep invaginations towards the germinal epithelium.

CONCLUSION

There is detectable damage of the lamina propria in adolescents affected by left idiopathic varicocele, although not as well developed or as severe as in adults.

Diastolic dysfunction and baroreflex sensitivity in hypertension

The determinants of diastolic dysfunction in patients with systemic hypertension are not completely known. To evaluate the possible role of age, arterial blood pressure, and baroreflex heart rate response impairment in causing diastolic dysfunction, we studied 61 patients (42 male; mean+/-SD age, 43.9+/-12 years) with newly recognized and therefore previously untreated systemic hypertension. Diastolic dysfunction was evaluated by means of Doppler echocardiography (and diagnosed as such when the early to atrial peak velocity ratio corrected to heart rate was <1), arterial blood pressure by 24-hour ambulatory monitoring, and baroreflex heart rate response by means of the spectral technique (alpha index) during paced (0.27 Hz) and spontaneous breathing (in a supine position and during tilt). Nineteen patients had diastolic dysfunction, the most powerful predictor of which was age (r=-0.63, P<0.001). The patients with diastolic dysfunction had significantly lower values for spectral baroreflex gain in the high-frequency band than those without (5.2+/-3 versus 8.4+/-5 ms/mm Hg during paced breathing, P<0.05; 7. 4+/-4 versus 13.3+/-7 ms/mm Hg in a supine position, P<0.05; 4.3+/-4 versus 5+/-2 ms/mm Hg during tilt, P<NS). Ambulatory blood pressure values were not significantly different in the patients with (137+/-14 and 89+/-9 mm Hg) and without (144+/-11 and 82+/-24 mm Hg) diastolic dysfunction. In conclusion, age and impaired baroreflex heart rate response (but not pressure overload) are determinants of left ventricular diastolic dysfunction in patients with newly recognized and untreated systemic hypertension.

[Hormone substitution therapy. Side-effects and compliance of various therapeutic regimens]

BACKGROUND

The aim of this study is to evaluate the tolerability and long-term compliance of four Estrogen Progestin treatments (HRT) for menopause.

METHODS

One hundred and ten symptomatic menopausal women were divided into four groups according to therapeutic regimens: A) Estradiol (E2) transdermal treatment 50 micrograms (TTS 50) continuously administered (cont.) plus Medroxyprogesterone Acetate (MPA) 10 mg/die for twelve days a month: 35 women. B) Conjugated Equine Estrogens (CEE) 0.625 mg/die cont. plus MPA for twelve days a month: 25 women. C) Estradiol transdermal 50 micrograms (cont.) plus MPA 2.5 mg/die cont.: 26 women. D) CEE 0.625 mg/die cont. plus MPA 2.5 mg/die cont.: 24 women.

RESULTS

Menopausal symptoms were significantly reduced with all treatments. During the first year group C and D patients showed irregular bleeding (group C: 46%, group D: 61%). After 24 months the bleeding frequency was reduced (group C: 11%, group D: 13%). Mastodynia was the more frequent side-effect in particular among women who were utilizing cont.comb. regimens. The total percentage of drop out (D.O.) after 2 years was more than 30% (Group A: 31%, Group B: 33%, Group C: 39%, Group D: 35%). The most frequent reasons for abandoning HRT (79% of all DO) were not linked to therapy side-effects. 19% of DO switched to other hormonal regimens.

Age-related decrease in cardiac tolerance to oxidative stress

Oxygen radical-mediated injury has been implicated in the process of cardiac aging. We investigated the tolerance to oxidative stress of hearts from rats of different age. Langendorff-perfused hearts from 3-12-month-old rats received a 30 min infusion of the reactive oxygen specie hydrogen peroxide (H2O2, 60 microM), followed by a 15 min wash-out. H2O2 infusion resulted in a significantly larger increase in end-diastolic pressure in hearts of 6- and 12-month-old rats than 3 months (P<0.01). In addition, developed pressure and rate-pressure product decreased more evidently in 12-month-old hearts (P<0.01 vs 3 and 6 months). Arrhythmia analysis showed higher score in hearts of 12- and 6-month-old rats with respect to 3-month-old animals (P<0.05). Cardiac release of oxidized glutathione (an index of the ability of the heart to inactivate oxygen metabolites) was significantly lower in hearts from rats of 6 and 12 months than in younger animals (P<0.001). Finally, cardiac concentrations of the scavenger enzymes glutathione peroxidase and Mn-superoxide dismutase also significantly decreased with age. In conclusion, in rat heart metabolic and functional tolerance toward oxidative stress decreases with age. This phenomenon may contribute to the development of cardiovascular alterations with increasing age.

Patent ductus arteriosus occlusion using detachable coils

Occlusion of patent ductus arteriosus was performed using detachable coils in 193 cases, with 181 successful implants and a low embolization rate. This technique is safe and effective for occlusion of ductuses of various sizes, and is low cost.