Quantification of left ventricular fibrosis in arrhythmic mitral valve prolapse patients: comparison of different semi-automated techniques assessed by cardiac magnetic resonance

Background

Left ventricular (LV) fibrosis has a key role in arrhythmogenesis in mitral valve prolapse (MVP) patients. Cardiac magnetic resonance (CMR) demonstrated able to clearly identify LV fibrosis with the post-contrast late gadolinium enhancement (LGE) images. Despite the pivotal role of LV fibrosis in the arrhythmogenesis, a quantification and identification of reproducible method able to accurately measure LGE in arrhythmic MVP patients has not been recognized.

Purpose

We aimed to measure and compare different semi-quantitative methods for LGE quantification assessed by CMR, in order to identify the most reproducible one, in arrhythmic MVP patients.

Methods

66 arrhythmic MVP patients with normal systolic function and without significant regurgitation were enrolled. Semi-automated gray-scale thresholding technique using full with at half maximum (FWHM) and 2, 3 and 5 standard deviation (SD) above the remote myocardium were used and compared with visual assessment (Fig. 1).

Results

LGE was identified in 41 arrhythmic MVP patients (62%) and quantified (Fig. 2). The mean quantity of LGE visually assessed was 2.40±1.07% or 1.40±0.82 g. With FWHM, LGE resulted 3.56±1.23% or 1.99±1.13 g. Using thresholding, the mean LGE quantity was 9.2±3.1% or 4.82±2.28 g for 2-SD, 5.72±1.75% or 3.06±1.47 g for 3-SD and 2.36±0.99% or 1.29±0.79 g for 5-SD. The 5-SD measurement in percentage demonstrated a good correlation with LGE quantification visually assessed (2.402±1.075 vs 2.363±0.9909, p: 0.543). Despite all semi-quantitative methods for LGE quantification demonstrated a good intra and inter-observer agreement, the 5-SD threshold quantification, both in percentage and in grams, revealed the less intra-observer (respectively, ICC: 0.976 and 0.966) and inter-observer variability (respectively ICC: 0.948 and 0.935) when compared with visual assessment.

Conclusion

This is the first study that quantified and compared different CMR semi-automated methods for LGE assessment in a population of arrhythmic MVP patients. The 5-SD gray-scale threshold technique in percentage revealed the best correlation with the visual assessment and an optimal reproducibility.

Funding Acknowledgement

Type of funding sources: None.

P129 IMPACT OF THE ATHEROSCLEROTIC PABULUM ON IN–HOSPITAL MORTALI–TY FOR SARS–COV–2 INFECTION. IS CALCIUM SCORE ABLE TO IDENTIFY AT RISK PATIENTS?

Background

Although the primary cause of death in COVID–19 infection is respiratory failure, there are evidences that cardiac manifestations may contribute to overall mortality and can even be the primary cause of death. More importantly, it is recognised that COVID–19 is associated with a high incidence of thrombotic complications.

Aim of the Study

evaluate if CAC score was useful to predict in–hospital mortality and complications in patients with COVID infection

Methods

Two–hundred–eighty–four patients with proven SARS–CoV2 infection who had a non–contrast Chest CT at our facility were retrospective analysed for coronary artery calcium (CAC) score. Primary endpoint was in–h mortality. Secondary end–points were need for mechanical ventilation and Intensive Care Unit admission. Clinical and radiological data were retrieved.

Results

Patients with coronary calcium had higher inflammatory burden at admission (D–dimer, CRP, Procalcitonin) and higher high–sensitive Troponin I (HScTnI) at admission and at peak. While there was no association with presence of consolidation and ground glass opacities, patients with coronary calcium had higher incidence of bilateral infiltration and higher in–hospital mortality. The main finding of our research is that CAC alone does not completely identify all the population at risk of events in the setting of COVID 19 patients. Peak HScTnI was associated with higher mortality, intensive care unit admission and mechanical ventilation in both univariable at multivariable analysis.

Conclusions

Together with the presence of higher inflammation burden CAC may be a useful marker in identifying patients at risk of cardiovascular complications and in hospital mortality.

C47 CORO–CT PLAQUE ANALYSIS IN ASSESSMENT OF CARDIOVASCULAR RISK

Background

Computed tomographic (CT) coronary angiography represents a non–invasive approach to assess plaque characteristics that provides information to change treatment of coronary artery disease (CAD) and to asses risk stratification.

Purpose

Analyze the differences in plaque composition between patients with different plaque features: soft unstable plaques, hard stable plaques and no plaques; identify whether there is a relationship between the plaque density and the pericoronary fat attenuation index (pFAI). Materials and methods: 372 patients retrospectively analyzed who underwent CTCA for exclusion of CAD. They were divided into three groups: 37 (10%) patients with high attenuated plaques (> 60HU), 137 (37%)with low attenuated plaques (<29 HU and a volume of at least 15 mm3 and/or 30–59 HU with a volume greater than 52 mm3) and 198 (53%) patients without significant CAD. For each patients we collected clinical, radiological and follow–up data.

Results and Discussion

Low–attenuated plaques are significantly associated with older age, male sex, dyslipidemia and diabetes mellitus (p < 0.001). Higher values of pFAI were more present in patients with soft plaques than in those with stable plaques and without plaques (p = 0.005). It was also found that soft plaques were present in more CA segments compared to stable plaques. Overall volume of soft plaque appears greater than hard plaques and mainly localized in the anterior descendant coronary artery with higher stenosis values (p < 0.001). Presence of plaques with soft or high–risk features predisposes significantly and independently (p < 0.001) to a composite outcome (death, in–hospital admissions for percutaneous angioplasty or by–pass procedures) at the follow up.

Conclusions

Coronary plaque analysis showed a good correlation between high–risk plaques and pFAI, supporting the hypothesis that the presence of high–risk plaques can be correlated to inflammatory burden. Furthermore, the presence of high risk plaques predispose to death or hospitalization for coronary intervention.

Coronary perivascular inflammation in type 2 diabetes mellitus patients: the missing piece in the puzzle of their increased cardiovascular risk?

Background

Coronary atherosclerosis is a frequent complication of type 2 diabetes mellitus (DM2). Considering the contiguity with the vascular wall, perivascular adipose tissue (PVAT) could play a crucial role in the pathogenic microenvironment of atherosclerosis. The PVAT attenuation index (p-FAI) is a non-invasive marker that reveals the change in peri-coronary adipose tissue (PCAT). High values of p-FAI are associated with increased cardiovascular mortality and poor prognosis. Emerging as an indication, contributor to, and therapeutic target for atherosclerosis, PCAT warrants further investigation in DM2.

Purpose

We aimed to characterize the association of PCAT by p-FAI and DM2, and to compare coronary inflammation in DM2 versus non DM2 patients with coronary artery disease (CAD), and versus healthy controls.

Methods

15 consecutive DM2 patients (9 male, age 63±10 years) without symptoms/signs of cardiovascular disease were included in the study and compared to 8 non DM2 patients with CAD and 13 healthy volunteers without cardiovascular diseases, matched for age and sex. All patients and controls underwent coronary computed tomography angiography (CCTA) for the evaluation of coronary arteries and p-FAI. All scans were performed using a 320-slice multidetector computed tomography (Toshiba Aquilion) and a prospective ECG-triggered sequential acquisition. p-FAI analysis was performed using a dedicated workstation (Aquarius iNtuition Edition version 4.4.13. P3; TeraRecon Inc., Foster City, CA, USA). The proximal 40-mm segment of the right coronary artery (RCA) was identified and the inner and the outer wall were automatically traced, excluding the 10 mm from the ostium. The adipose tissue localized within a radial distance from the outer wall equal to a medium diameter of the RCA was evaluated. Voxel histograms of CT attenuation were traced and included between −190 to −30 HU within the PCAT volume. p-FAI was calculated as the median CT attenuation value of PCAT of the proximal 40-mm segment of the RCA (Figure 1).

Results

CAD was present in 10 DM2 patients (5 males, aged 63.1±10.5 years); in 5 DM2 patients (4 males, aged 63±11 years) epicardial coronary arteries were normal. p-FAI was higher in DM2 patients than in healthy controls (p=0.004). The presence of CAD did not impact on p-FAI in DM2 patients, presenting a comparable value (p=0.37). p-FAI was higher in DM2 patients with CAD than in non DM2 patients with CAD (p=0.04). Moreover, p-FAI was higher in DM2 patients without CAD than in non DM2 patients with CAD (p=0.002, Figure 2). Finally, p-FAI was not different in non DM2 patients with CAD compared to healthy controls (p=0.65), suggesting the limited role of CAD in the progression of peri-coronary inflammation when compared to DM2.

Conclusions

Coronary inflammation evaluated by p-FAI measurement was higher in DM2 patients, also without CAD. Therefore, our results suggest that DM2 is a determinant of coronary inflammation stronger than CAD.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Left ventricular thrombosis following apical myocardial infarction: may CMR strain analysis tell us something?

Funding Acknowledgements

Type of funding sources: None.

Background

 Left ventricular thrombosis (LVT) is a possible complication following myocardial infarction (MI). Besides infarct size, risk factors for LVT include ST-elevated MI (STEMI), anterior and apical location, reduced left ventricular ejection fraction (LVEF) and the presence of microvascular obstruction. Echocardiography quantified myocardial strain has been associated with LVT following MI. Recently, global longitudinal strain, calculated with feature tracking (FT) - CMR, emerged as an independent predictor of major cardiovascular events following MI. Anyway, the relationship between abnormalities on FT-CMR and LVT following MI is still unexplored. Aim of our study is to investigate the possible association between abnormal strain on FT-CMR and LVT following apical STEMI.

Methods

 We performed a retrospective analysis including all patients with a previous apical STEMI, who underwent CMR at our Institute between August 2013 and October 2020. Patients with ongoing anticoagulant therapy were excluded. Differences in global and segmental strain on CMR between patients with and without LVT were tested in a propensity-matched sample, using LVEF, age, gender, time from MI diagnosis and number of LV segments with transmural late gadolinium enhancement (LGE) as covariates to assign propensity score. Furthermore, difference in terms of apical to global radial strain percentual deviation (AGD), calculated as [(Global Radial Strain – Apical Radial Strain)/Global Radial Strain] * 100, was tested. 

Results

 Of 356 patients with apical STEMI undergoing CMR at our center, 37 (10.4%) were diagnosed with LVT. After performing a propensity score matching, we obtained a sample of 36 pairs, with a mean age of 65 (SD 11) years, and a median EF of 35% (IQR 27-42); 59 (82%) of them were male. A significant difference in terms of apical radial strain was found between the two groups, with a median strain of 10.75 (IQR 6.8–16.5) in patients without LVT compared to a value of 5.25 (IQR 2.7–9-6) in patients with LVT (p = 0.007). No differences were found in terms of global longitudinal, radial and circumferential strain (p = 0.19, p= 0.2 and p= 0.49 respectively) and segmental circumferential and longitudinal strain. When considering the AGD parameter, a significant difference was found between the two groups, with a median deviation of 12% (IQR -20; +48) in patients without LVT and 51% (IQR +47; +75) in patients with LVT (p= 0.0003). Furthermore, an AGD value of 26% was found to be the most accurate in terms of sensitivity and specificity applying a Receiver Operating Characteristic (ROC) curve analysis (AUC 0.74; CI 0.62-0.85).

Conclusions

 Among patients with transmural MI involving LV apex, reduced apical radial strain on FT-CMR is associated with the presence of LV thrombosis. Furthermore, among patients developing LV thrombi, a greater apical radial strain deviation from the global one was found, with a threshold value of 26% at ROC curve analysis.

Left ventricular myocardial deformation abnormalities in arrhythmic mitral valve prolapse: which comes first?

Funding Acknowledgements

Type of funding sources: None.

Background. Arrhythmic mitral valve prolapse (MVP) is characterized by left ventricular (LV) fibrosis in the basal inferolateral wall and papillary muscles. We hypothesized that LV fibrosis are driven by excessive mechanical forces acting on myocardial susceptible cells, representing the last step in the MVP-induced myocardial stretch process. Purpose. We aimed to evaluate the LV myocardial deformation, using strain assessed with cardiac magnetic resonance (CMR), in arrhythmic MVP patients with normal LV ejection fraction (LVEF) and absent/trivial mitral regurgitation (MR) and its correlation with the presence of LV fibrosis, detected by late gadolinium enhancement (LGE) in post-contrast CMR images. Methods. We enrolled consecutive arrhythmic MVP patients with normal LVEF and no/trivial MR. Sixty-nine (39 female; median age: 40 years) patients without MVP, arrhythmias or cardiovascular history served as control group. All patients underwent CMR for identification of LGE and evaluation of LV myocardial deformation. Results. A total of 66 patients were enrolled (47 female; median age: 44 years). In the overall MVP population, LGE was present in 41 patients (62.1%). MVP patients without LGE (25 patients, 37.9%) presented a higher global radial (median: 42.19 vs 33; p: <0.0001) and higher global longitudinal strain (median: -21.61 vs -18.10; p: <0.0001), compared to the control group. A reduction of regional basal posterolateral radial (BPL median: 50.60 vs 67.30; p: 0.0015) and longitudinal strain (BPL median: -23.50 vs -26.70; p: 0.0186) were observed in the MVP patients as compared with controls (Figures A-D). Conversely to the basal region, mid anterolateral and posterolateral region presented a higher radial (MAL median: 52.60 vs 31.10; p: < 0.0001 and MPL median: 52.80 vs 21.50; p: < 0.0001) and longitudinal strain (MAL median: -24.80 vs -18.30; p: < 0.0001 and MPL median: -25.30 vs -14.80; p: < 0.0001), when compared to control group. MVP patients with LGE had a lower global radial (median: 36.48 vs 42.19; p: <0.0047), longitudinal (median: -19.18 vs -21.61; p: 0.0013) and circumferential strain (median: -17.80 vs -19.28; p: 0.0134) compared with those without fibrosis. According to MVP patients without LGE, the presence of fibrosis is associated with a lower regional radial (BAL median: 64.40 vs 82.80; p: 0.0481; MAL median: 42.60 vs 52.60; p: 0.0287) and circumferential strain (BAL median: -21.90 vs -24.20; p: 0.0174; BPL median: -16.80 vs -18.80; p: 0.0411; MPL median: -15.50 vs -19.40; p: 0.0077) in the LV basal-mid lateral walls (Figures E-I). Conclusions. Arrhythmic MVP patients with normal LV systolic function and absent/trivial MR presented an abnormal myocardial deformation pattern. The reduced strain in BPL wall of MVP patients without LGE could be considered as an early marker of MVP-induced myocardial stress, that could promote, time by time, LV fibrosis and arrhythmias in MVP patients.

Radiomics: a new tool to differentiate adrenocortical adenoma from carcinoma

Background

The main challenge in the management of indeterminate incidentally discovered adrenal tumours is to differentiate benign from malignant lesions. In the absence of clear signs of invasion or metastases, imaging techniques do not always precisely define the nature of the mass. The present pilot study aimed to determine whether radiomics may predict malignancy in adrenocortical tumours.

Methods

CT images in unenhanced, arterial, and venous phases from 19 patients who had undergone resection of adrenocortical tumours and a cohort who had undergone surveillance for at least 5 years for incidentalomas were reviewed. A volume of interest was drawn for each lesion using dedicated software, and, for each phase, first-order (histogram) and second-order (grey-level colour matrix and run-length matrix) radiological features were extracted. Data were revised by an unsupervised machine learning approach using the K-means clustering technique.

Results

Of operated patients, nine had non-functional adenoma and 10 carcinoma. There were 11 patients in the surveillance group. Two first-order features in unenhanced CT and one in arterial CT, and 14 second-order parameters in unenhanced and venous CT and 10 second-order features in arterial CT, were able to differentiate adrenocortical carcinoma from adenoma (P < 0.050). After excluding two malignant outliers, the unsupervised machine learning approach correctly predicted malignancy in seven of eight adrenocortical carcinomas in all phases.

Conclusion

Radiomics with CT texture analysis was able to discriminate malignant from benign adrenocortical tumours, even by an unsupervised machine learning approach, in nearly all patients.

Relationship between papillary muscles abnormalities and apparently unexplained infero-lateral T-wave inversion in athletes

Aims

To evaluate by cardiac magnetic resonance (CMR) if left ventricle papillary muscle abnormalities, such as hypertrophy and abnormal location, may be the anatomo-functional substrates responsible for TWI inversion in lateral or infero-lateral leads in otherwise healthy athletes.

Methods

We included competitive athletes with TWI in lateral or infero-lateral leads in the absence of cardiac diseases detected by CMR. The control population included healthy athletes with normal ECG, matched for age and gender. We compared thickness, volume (both absolute and relative to the cardiac mass) and position of the papillary muscles between cases and controls.

Results

We included 53 athletes with apparently unexplained TWI in the lateral or infero-lateral leads (median age 20 years (17–42), 86.8% males) and 53 athletes with no TWI matched for age and gender. 4 patients (7.6%) had family history for cardiomyopathy or sudden cardiac death. Athletes with TWI showed more hypertrophic papillary muscles compared to controls, with statistically significant difference in diameter, area and volume (p&lt;0.01). The median ratio between the papillary muscles and the left ventricular mass was 4.4% among athletes with TWI versus 3% among those without TWI (p&lt;0.001). Papillary muscles showed apical displacement in 47% of cases, compared to 17% in the control group (p=0.001).

Conclusions

Idiopathic TWI in lateral or infero-lateral leads is associated with left ventricle papillary muscle hypertrophy and their apical displacement detected by CMR. The comprehension of clinical and prognostic significance of papillary muscle abnormalities responsible for these ventricular repolarization alterations requires further studies.

Example

Funding Acknowledgement

Type of funding source: None

Changes of forest cover and disturbance regimes in the mountain forests of the Alps

Natural disturbances, such as avalanches, snow breakage, insect outbreaks, windthrow or fires shape mountain forests globally. However, in many regions over the past centuries human activities have strongly influenced forest dynamics, especially following natural disturbances, thus limiting our understanding of natural ecological processes, particularly in densely-settled regions. In this contribution we briefly review the current understanding of changes in forest cover, forest structure, and disturbance regimes in the mountain forests across the European Alps over the past millennia. We also quantify changes in forest cover across the entire Alps based on inventory data over the past century. Finally, using the Swiss Alps as an example, we analyze in-depth changes in forest cover and forest structure and their effect on patterns of fire and wind disturbances, based on digital historic maps from 1880, modern forest cover maps, inventory data on current forest structure, topographical data, and spatially explicit data on disturbances. This multifaceted approach presents a long-term and detailed picture of the dynamics of mountain forest ecosystems in the Alps. During pre-industrial times, natural disturbances were reduced by fire suppression and land-use, which included extraction of large amounts of biomass that decreased total forest cover. More recently, forest cover has increased again across the entire Alps (on average +4% per decade over the past 25-115 years). Live tree volume (+10% per decade) and dead tree volume (mean +59% per decade) have increased over the last 15-40 years in all regions for which data were available. In the Swiss Alps secondary forests that established after 1880 constitute approximately 43% of the forest cover. Compared to forests established previously, post-1880 forests are situated primarily on steep slopes (>30°), have lower biomass, a more aggregated forest structure (primarily stem-exclusion stage), and have been more strongly affected by fires, but less affected by wind disturbance in the 20th century. More broadly, an increase in growing stock and expanding forest areas since the mid-19th century have - along with climatic changes - contributed to an increasing frequency and size of disturbances in the Alps. Although many areas remain intensively managed, the extent, structure, and dynamics of the forests of the Alps reflect natural drivers more strongly today than at any time in the past millennium.

Calcium metabolism & hypercalcemia in adults

Calcium is essential for many metabolic process, including nerve function, muscle contraction, and blood clotting. The metabolic pathways that contribute to maintain serum calcium levels are bone remodeling processes, intestinal absorption and secretion, and renal handling, but hypercalcemia occurs when at least 2 of these 3 metabolic pathways are altered. Calcium metabolism mainly depends on the activity of parathyroid hormone (PTH). Its secretion is strictly controlled by the ionized serum calcium levels through a negative feed-back, which is achieved by the activation of calcium-sensing receptors (CaSRs) mainly expressed on the surface of the parathyroid cells. The PTH receptor in bone and kidney is now referred as PTHR1. The balance of PTH, calcitonin, and vitamin D has long been considered the main regulator of calcium metabolism, but the function of other actors, such as fibroblast growth factor-23 (FGF-23), Klotho, and TPRV5 should be considered. Primary hyperparathyroidism and malignancy are the most common causes of hypercalcemia, accounting for more than 90% of cases. Uncontrolled hypercalcemia may cause renal impairment, both temporary (alteration of renal tubular function) and progressive (relapsing nephrolithiasis), leading to a progressive loss of renal function, as well as severe bone diseases, and heart damages. Advances in the understanding of all actors of calcium homeostasis will be crucial, having several practical consequences in the treatment and prevention of hypercalcemia. This would allow to move from a support therapy, sometimes ineffective, to a specific and addressed therapy, especially in patients with chronic hypercalcemic conditions unsuitable for surgery.

Molecular adsorbent recirculating system (MARS) application in liver failure: clinical and hemodepurative results in 22 patients

PURPOSE

Acute liver failure (ALF) and acute on chronic liver failure (ACLF) still show a poor prognosis. MARS was used in 22 patients with ALF or ACLF to prolong patient survival for liver function recovery or as a bridge to transplantation.

DESIGN

Evaluation of depurative efficiency, biocompatibility, hemodynamics, encephalopathy (HE) and clinical outcome.

PROCEDURES

During 71 five-hour sessions we evaluated (0', 60', 120', 180', 240', 300'): bilirubin, ammonia, cholic acid (CCA), chenodeoxycholic acid (CCDCA), leukocytes, platelets, hemoglobin and mean arterial pressure (MAP). Serum creatinine, electrolytes, cardiac output, cardiac index (bioimpedence) and HE (West Haven Criteria score) were evaluated at 0' and 300'. STATISTICAL METHODS AND OUTCOME MEASURES: Student's t-test for pre- vs. end-session values was used. For bilirubin and ammonia the correlation test was made between pre- and end-session values and between pre-session values and removal rates (RRS).

MAIN FINDINGS

Survival was 90.9% at 7 days, 40.9% at 30 days. Pre- vs. end-session: bilirubin from 37.2 +/- 12.5 mg/dL to 24.9 +/- 8.9 mg/dL (p < 0.01), ammonia from 88.0 +/- 60.4 micromol/L to 43.6 +/- 32.9 micromol/L (p < 0.01), CCA from 42.8 +/- 21.0 micromol/L 18.2 +/- 9.8 micromol/L (p < 0.01), CCDCA from 26.3 +/- 6.3 micromol/L to 15.7+/-7.6 micromol/L (p<0.01). The correlation test between pre-session values of bilirubin and ammonia vs. RR S was respectively 0.32 (p = 0.01) and 0.30 (p = 0.04). Leukocytes, platelets and hemoglobin remained stable. MAP increased from 82.0 +/- 12.0 mmHg to 87.0 +/- 13.0 mmHg (p < 0.05), West Haven Criteria score decreased from 2.7 +/- 0.7 to 0.7 +/- 0.7 (p < 0.001).

CONCLUSION

MARS treatment led in all patients to an improvement of clinical, hemodynamic and neurological conditions, with significant reduction in the hepatic toxins blood level. Treatment biocompatibility and tolerance were satisfactory.

K-Cl cotransport modulation by intracellular Mg in erythrocytes from mice bred for low and high Mg levels

Mg is an important determinant of erythrocyte cation transport system(s) activity. We investigated cation transport in erythrocytes from mice bred for high (MGH) and low (MGL) Mg levels in erythrocytes and plasma. We found that K-Cl cotransport activity was higher in MGL than in MGH erythrocytes, and this could explain their higher mean corpuscular hemoglobin concentration, median density, and reduced cell K content. Although mouse KCC1 protein abundance was comparable in MGL and MGH erythrocytes, activities of Src family tyrosine kinases were higher in MGH than in MGL erythrocytes. In contrast, protein phosphatase (PP) isoform 1 alpha (PP1 alpha) enzymatic activity, which has been suggested to play a positive regulatory role in K-Cl cotransport, was lower in MGH than in MGL erythrocytes. Additionally, we found that the Src family kinase c-Fgr tyrosine phosphorylates PP1 alpha in vitro. These findings suggest that in vivo downregulation of K-Cl cotransport activity by Mg is mediated by enhanced Src family kinase activity, leading to inhibition of the K-Cl cotransport stimulator PP1.

Audiogenic seizure sensitivity in mouse lines genetically selected for high versus low blood magnesium levels

The MGH and MGL mouse lines, genetically selected for high and low blood magnesium (Mg) levels, respectively, exhibit marked differences for characteristics expected to be related to blood Mg levels, such as increased stress sensitivity and stress-induced aggressivity in MGL mice. However, although Mg deficiency experimentally induced by low oral Mg intake has been shown previously to increase susceptibility to audiogenic seizures, MGL were less sensitive to audiogenic seizures than MGH mice. The MGH-MGL lines may, therefore, provide a beneficial and complementary model for the study of the relationships between audiogenic seizures and blood Mg levels.

The rat microphthalmia-associated transcription factor gene (Mitf) maps at 4q34-q41 and is mutated in the mib rats

The rat gene encoding the microphthalmia-associated transcription factor (Mitf) was assigned to rat Chromosome (Chr) 4q34-q41, as well as the Gata2 and Mem1 genes. Rat Chr 4 is homologous to mouse Chr 6 and human Chr 3, which carry the Mitf (MITF) gene in these species (MMU 6, 40.0 cM, and HSA 3p14.1-p12.3). mib/mib rats, which are characterized by depigmentation, microphtalmy, osteopetrosis, and neurological disorders were shown to bear a deletion covering several kilobases of genomic DNA in the Mitf gene and to lack Mitf mRNA. The Mitf mutation in the mib/mib rats is thus very likely to be a Mitf null mutation, causing a phenotype similar to the one observed in the miVGA-9 mice, but including osteopetrosis as an additional feature.

Unexpected association between reproductive longevity and blood magnesium levels in a new model of selected mouse strains

Two recently described mouse strains, with high (MGH) and low (MGL) blood magnesium (Mg) levels were obtained by selection over 19 generations. Both strains exhibit strong differences for characteristics generally known to be related to blood Mg levels, such as increased stress sensitivity and stress-induced aggressivity in MGL mice. In contrast, while experimental Mg deficiency due to low oral Mg intake has been shown to shorten life span and lower reproductive ability, reproductive longevity was longer in the MGL than in the MGH strain. Interestingly, the life spans of the two strains are very similar. Although this character could have been fixed in the strains by chance, with no relationship to the blood Mg level, the possibility of a causal link with the selection cannot be ruled out and is discussed. Regardless of the mechanisms at stake, the MGH and MGL strains appear to constitute a new model for the study of the relationships between reproductive longevity and blood Mg levels.

[Role of surgical therapy in the treatment of refractory ascites]

In 5-10% of cases ascites is not controlled by medical therapy and is defined refractory. These patients may be submitted to one of the four following surgical options: portal-systemic shunt, peritoneo-venous shunt, transjugular intrahepatic portal-systemic shunt, orthotopic liver transplantation. Although the portal-systemic shunt is efficient in clearing ascites, it does not improve the survival, which depends on liver function, and it is complicated by an important incidence of encephalopathy. Since the patients with refractory ascites and good hepatic risk are not usually many, it is possible to understand why derivative surgery has been disappointing with this indication. Although the peritoneo-venous shunt is associated with a significant rate of valve obstruction, it is an easy, effective and not expensive treatment. So, till now, it has been considered the first choice procedure of refractory ascites, if any situations, determinating the onset of postoperative complications, are not present. Recently a new method has been introduced in the therapy of portal hypertension, the transjugular intrahepatic portal-systemic shunt. This is a bloodless portal-systemic derivation and so it has caused great enthusiasm even if the available data are insufficient to give a definitive opinion on its role in management of ascites. Certainly the liver transplantation, which presents the great advantage to treat both the cirrhosis and its complications, seems to be the most rational therapy for these patients. However, at least for this moment, the well-known absence of organ donors makes still actual the palliative surgical measures.

Mice selected for low and high blood magnesium levels: a new model for stress studies

Extra- and intracellular magnesium levels have previously been shown to be genetically controlled in humans and in the mouse. To further study this genetic regulation, mice were selected from a heterogeneous population, for low (MGL mice) and high (MGH mice) red blood cell (RBC) magnesium values. These values diverged rapidly in the two strains, to reach a stable difference between the 14th and 18th generations. MGL mice also exhibited significantly lower plasma, kidney, and skull bone magnesium contents and higher urinary magnesium excretion and total brain weights. Moreover, in stressful conditions, MGL mice displayed a more aggressive behavior that the control MGH strain. Altogether, MGL mice showed a more restless behavior, a higher rectal temperature, and much higher brain (+17%) and urine (+200%) noradrenaline levels than the MGH animals. These strains, thus, constitute a new animal model for the study of magnesium metabolism and its relationships with catecholamines, stress sensitivity, and aggressive behavior.

A combined regimen of cyproterone acetate and testosterone enanthate as a potentially highly effective male contraceptive

In this study we tested the effectiveness of the combined administration of cyproterone acetate (CPA) and testosterone enanthate (TE) in suppressing spermatogenesis. After a control phase of 3 months, 15 normal men were randomized to receive TE (100 mg/week) plus CPA at a dose of 100 mg/day (CPA-100; n = 5) or 50 mg/day (CPA-50; n = 5) or TE (100 mg/week) alone (n = 5) for 16 weeks. Semen analysis was performed every 2 weeks. Every 4 weeks, fasting blood samples were drawn for the measurement of LH, FSH, testosterone, estradiol, and biochemical and hematological parameters; subjects underwent a physical examination; and they and their partners filled in a sexual and behavioral questionnaire. Regardless of the dose, each of the 10 subjects receiving CPA plus TE became azoospermic, whereas only 3 of 5 subjects treated with TE alone achieved azoospermia. Times to azoospermia were 6.8 +/- 0.5, 8.4 +/- 1.0, and 14.0 +/- 1.2 weeks in groups CPA-100, CPA-50, and TE alone, respectively (P = NS). Throughout treatment, both gonadotropins tended to be higher in the TE alone group than in the other groups. This difference was mostly due to the higher gonadotropin levels present in the 2 men treated with TE alone that remained oligospermic. No difference in testosterone or estradiol levels was found among the groups. No significant change in lipoprotein levels or liver function tests could be detected. In the CPA-100 and CPA-50 groups, hemoglobin, hematocrit, and red blood cells were lower at the end of the treatment phase, whereas no change was detected in TE alone group. A tendency for a decrease in body weight was detected in subjects treated with CPA, whereas there was no change in subjects receiving TE alone. At the end of the treatment phase, a decrease in testis size was present in all groups. There was no significant change in sexual function, aggressive behavior, mood states, or satisfaction with relationship in any group. These results suggest that the combined administration of CPA and TE is very effective in suppressing spermatogenesis and may represent a promising regimen for reversible contraception in males.

Imbalance towards Th1 predominance is associated with acceleration of lupus-like autoimmune syndrome in MRL mice

To investigate the respective roles of Th1 and Th2 cells in the pathogenesis of lupus-like autoimmune disease, we have analyzed the spontaneous and antigen-induced productions of IgG1 vs IgG2a and IgG3 subclasses in relation to the mRNA expression of INF-gamma (Th1 cytokine promoting IgG2a and IgG3 production), IL-4 (Th2 cytokine promoting IgG1 production), and IL-10 (Th2 cytokine) in CD4+ T cells from lupus-prone MRL mice. For this purpose, two paired sets of MRL mice were chosen for the comparison of these parameters: (a) MRL-lpr/lpr (lpr for lymphoproliferation) and its recently described substrain with a prolonged survival, termed MRL-lpr/lpr.ll (ll for long lived) and (b) MRL male mice bearing the Yaa (Y-linked autoimmune acceleration) gene (MRL.Yaa) with an accelerated disease and their male counterparts lacking the Yaa gene. We demonstrate herein that the accelerated development of lupus-like autoimmune disease in MRL-lpr/lpr and MRL.Yaa mice, as compared with MRL-lpr/lpr.ll and MRL-+/+ mice, respectively, was correlated with an enhanced expression of IFN-gamma vs IL-4 and IL-10 mRNA in CD4+ T cells, which paralleled with an increase of spontaneous and foreign T cell-dependent antigen-induced productions of IgG2a and IgG3 vs IgG1 antibodies. These data suggest that an imbalance towards Th1 predominance may play a significant role in the acceleration of lupus-like autoimmune disease in MRL mice.

[The correlation between morphology, electrolytic content and risk factors in breast cysts]

Many studies on the biochemical composition of the liquid aspirated from breast cysts have identified three types of cysts: type I (apocrine) cysts, with a high concentration of K+ and low levels of Na+ and C1-; type II (transudate) cysts, with an electrolytic content similar to that of plasma and high Na+ levels and, finally, type III cysts, with intermediate characteristics. The literature data appear to indicate that the women with type I cysts are at higher risk for breast cancer. The authors report the results of a study carried out on 143 women from October, 1991, through October, 1994, in the Radiology Department of the University of Bologna, to investigate the correlations between some risk factors for breast cancer, the characteristics of cyst fluid and the morphology of the cysts after pneumocystography. Of 186 cysts, 104 (55.9%) were type I, 49 (26.4%) were type II, and 33 (17.7%) were type III. Among the risk factors we considered, only the premenopausal state (41 to 45 years of age) exhibited a statistically significant correlation with the presence of type I cysts. The morphological study of the cysts after pneumocystography showed a surprisingly high correlation between the honeycomb pattern and type I cysts. The constant correlation between cyst morphology and electrolytic content may allow the easy identification of the subgroups of patients eligible for a closer follow-up.

Fully and long-term xenogeneic hematopoietic chimeras created in poorly concordant rat-mouse combinations: expression of hereditary donor characteristics

We created fully and stable xenogeneic hematopoietic chimeras in "poorly concordant" rat-mouse strain combinations defined by their high histocompatibility-antigen disparity and by the high titer of mouse-serum natural cytotoxic antibodies (NcAb) to rat donor bone marrow cells (BMC). Recipients were adult male (C57BL/6 x DBA/2)F1 (BDF1) mice, and donors of untreated BMC were adult male WAG strain rats. We tried several approaches to improve the quality and the stability of the rat-cell engraftment and to avoid the risk of graft-vs.-host reaction (GVHR). Best results were obtained when: 1) BDF1 recipients were previously thymectomized and then heavily irradiated to lower their immunocompetence; 2) irradiated recipients were implanted with a newborn BDF1 thymus, which allows maturing rat T lymphoid cells to be made tolerant to mouse antigens in vivo, which lowered the risk of GVHR; and 3) recipients were given a high number of untreated rat BMC (4-5 injections of 1.6 x 10(7) cells) to reduce the risk of rejection of rat BMC by mouse NcAb. We found that rat BMC engraftment was highly effective (75 to 100% rat hemoglobin and 100% rat IgG) and long-lasting (more than 10 months). The grafted rat cells were very tolerant toward host histocompatibility antigens but maintained all their immunological potentialities. Moreover, using the "poorly concordant" Wistar Furth (WF)-BDF1 combination, we showed that a genetically controlled characteristic of the hematopoietic system of the WF rat donor was maintained and functionally expressed in the xenogeneic environment of BDF1 mice.

Sclerotherapy plus octreotide versus sclerotherapy alone in the prevention of early rebleeding from esophageal varices: a randomized, double-blind, placebo-controlled, multicenter trial. New Italian Endoscopic Club

Because of its ability to decrease portal pressure, azygos blood flow, and postprandial splanchnic hyperemia, octreotide administration could be effective in reducing early rebleeding in patients undergoing endoscopic variceal sclerotherapy (EVS). We report the results of a trial comparing EVS + octreotide versus EVS alone. Consecutive patients with cirrhosis and endoscopically proven variceal hemorrhage were considered eligible for the trial if hemodynamically stable for at least 24 hours after bleeding stopped. Patients with advanced liver cancer or having received EVS treatment in the past were not enrolled. After enrollment patients were submitted to EVS (day 1); all patients were randomized to receive octreotide, 100 micrograms three times a day subcutaneously, or an identical placebo, up to day 29; EVS was repeated at days 8, 15, and 29. Fifty-eight patients were randomized to receive either EVS + octreotide (n = 26) or EVS alone (n = 32). The two groups were evenly balanced for sex, age, Child-Pugh class, history of previous bleeding, endoscopic appearance of varices, or treatment received in emergency. Eight of 26 (31%) patients in the EVS + octreotide group rebled, compared with 11 of 32 (34%) in the EVS group. Four of the eight (50%) patients in the former group and 8 of 11 (73%) in the latter, respectively, bled within day 15. There were 10 (38.5%) deaths in the EVS + octreotide group (seven bleeding-related), compared with seven (21.9%) (five bleeding-related) in the EVS group; these differences did not reach statistical significance. Administration of octreotide, 100 micrograms three times a day, subcutaneously, to patients undergoing EVS for prevention of recurrent variceal bleeding does not decrease the incidence of early rebleeding.

Effects of aerobic and nonaerobic exercise on anxiety, absenteeism, and job satisfaction

The effects of aerobic and nonaerobic exercise on employee state and trait anxiety levels, absenteeism, job satisfaction, and resting heart rate were investigated within a worksite setting. Results indicated that aerobic subjects significantly reduced their state anxiety levels over a single exercise session. Post-exercise state anxiety decreased over the 8 weeks for both groups. Aerobic subjects who were not previous exercisers decreased their trait anxiety. No changes in job satisfaction, absenteeism, or resting heart rate were evident. These results support past findings that concluded that aerobic exercise is superior to nonaerobic exercise for anxiety reduction. Tentative evidence was found to oppose the hypothesis that cardiovascular conditioning is the mechanism responsible for the psychological benefits because no significant cardiovascular changes occurred.

Evidence for a multigenic system controlling methyl-beta-carboline-3-carboxylate (beta-CCM)-induced seizures

beta-CCM is a beta-carboline known to have properties opposite to those of benzodiazepines. Our approach was to analyze, in mice, the genetic mechanisms involved in beta-CCM-induced myoclonic seizures using recombinant congenic strains and F1 hybrids issued from these strains. Our aim was to define the extent of the multigenic character of beta-CCM-induced myoclonic seizures, while also evaluating the distribution of the strength of the genes implicated in this trait. The results show that the control of reactivity to beta-CCM is multigenic with notable epistatic involvement.

Prevention of reperfusion syndrome in acute muscular ischaemia with free radical scavengers and membrane-protecting compounds: an experimental study

The prevention of oxidant-induced damage following reperfusion was experimentally evaluated. Two pharmacological regimens containing different combinations of antioxidant factors and membrane-stabilizing compounds, such as alpha-tocopherol (vitamin E), methionine, dexamethasone, mannitol and cysteine, were administered. The reduced/oxidized glutathione (GSH/GSSG) ratio in muscle was used to evaluate oxidative stress. Ischaemia was induced by occluding the aorta and the inferior vena cava with an irrigation-occlusion catheter. After 4 h of ischaemia, five sheep were reperfused without any treatment (control group) and five treated with an endoaortic bolus administered at declamping (treatment 1). In five other sheep, treatment started during ischaemia (treatment 2). Ischaemia and, in particular, reperfusion significantly reduced the muscle GSH content, compared with the basal value in the control group; thus the GSH/GSSG ratio decreased significantly in the control group from 10.5(2.2) (mean(s.e.) basal value) to 0.687(0.3) at reperfusion (P < 0.009). Both treatments 1 and 2 significantly prevented a reduction in GSH content induced by reperfusion following ischaemia; the GSH/GSSG ratio (10.5(2.2) basal value) increased to 19.67(4.6) with reperfusion in the treatment group 1, mainly because of a lower decrease of GSH and a lower level of GSSG while it did not change in treatment group 2 (10.7(5.0)). Levels of creatine phosphokinase did not change in the treated groups, although they increased significantly in the control group (P < 0.006). Although oxidative stress is not the only cause of damage in revascularization, this study confirms the protective ability of treatment with free radical scavengers and membrane-stabilizing compounds.

An MRL/MpJ-lpr/lpr substrain with a limited expansion of lpr double-negative T cells and a reduced autoimmune syndrome

The autosomal recessive mutant gene, lpr, has been shown to accelerate the progression of lupus-like autoimmune disease, which is associated with a massive expansion of a unique CD4-CD8- double-negative T cell subset, in MRL/MpJ mice. Here we report a substrain of MRL/MpJ-lpr/lpr (MRL-lpr) mice which live almost twice as long with delayed development of glomerulonephritis, compared with conventional MRL-lpr mice. This substrain, termed MRL-lpr.II (II for long-lived), develops generalized lymphadenopathy characteristically seen in MRL-lpr mice. However, the expansion of a double negative lpr T cell subset is markedly limited with a mean value of 15% in their lymph nodes compared to about 70% in conventional MRL-lpr mice. Overall production of autoantibodies, such as anti-DNA and rheumatoid factors, does not significantly differ between the two MRL-lpr mice. However, serum levels of cryoglobulins, whose major component is IgG3, are markedly diminished in MRL-lpr.II mice with a parallel decrease in IgG3. Since MRL-lpr.II mice still carry the lpr mutation, as documented by the presence of defects in the Fas antigen, a possible new mutation in this substrain may play a significant role in the pathogenesis of lupus-like autoimmune syndrome.

Strong allelic selection in the course of brother x sister matings in mice

A set of 36 recombinant congenic mouse strains, resulting from crosses between B10.D2 and DBA/2, was created. During the backcross phase, animals were selected for their sensitivity to the graft-versus-host reaction induced by a B10.D2 hematopoietic cell transplant after irradiation. The progress of inbreeding was followed throughout the brother x sister phase by determining the allelic form of 14 genetic markers. During the backcross phase, the mean selective value per generation and per marker for the heterozygous allelic combination was 2.81 (1 for the homozygous B10.D2). During the brother x sister phase, this value was 1.15 and 0.30 for the heterozygous and the DBA/2 homozygous combinations, respectively (1 for the homozygous B10.D2). The origin of this strong allelic disadvantage for the DBA/2 homozygote, in the face of countervailing selection, is discussed. These data strongly suggest coadaptation between alleles constituting the genome of the inbred strains of the laboratory mouse, resulting in strong counterselection of the alleles derived from one inbred strain when a small amount is spread over the genetic background of another inbred strain.

Recombinant congenic strains of mice from B10.D2 and DBA/2: their contribution to behavior genetic research and application to audiogenic seizures

Recombinant congenic strains (RCS) represent a series of related strains, each of which carries a small fraction of the genome of one strain ("donor" strain) on the genetic background of another strain ("background" strain). Recombinant inbred strains (RIS) are commonly used to identify major gene segregation and linkage and associations between behavior and quantitative trait loci, whereas recombinant congenic strains (RCS) open other complementary leads. The variability in the reactivity of RCS to a trait is thus the expression of few minor-effect genes originating from the donor strain, because the probability that major genes are present in any one RCS is low. Unlike RIS in which minor-effect genes are often masked by major genes, RCS enable the effects of minor genes to be studied. With our method, for a given trait, an estimate can be made of the gene strength distribution as well as an estimate of the minimal number of genes involved having a certain strength.

Lipid, lipoprotein, and apolipoprotein assessment during an 8-wk very-low-calorie diet

The influence of a very-low-calorie diet (VLCD) on lipid pattern is controversial. To evaluate the long-term effect of semistarvation on lipid patterns, a group of severely obese patients [aged 37 +/- 12 y, body mass index (BMI) 40.0 +/- 0.9] underwent a VLCD for 8 wk. Total cholesterol (TC), LDL cholesterol (LDL-C), and HDL cholesterol (HDL-C), triglycerides (TGs), apolipoproteins A1 (apo A1) and B (apo B) were analyzed every week. TC (6.07 +/- 0.23 vs 5.53 +/- 0.25 mmol/L, P less than 0.0008), HDL-C (mmol/L 1.26 +/- 0.06 vs 1.04 +/- 0.05 mmol/L, P less than 0.0001), TGs (1.46 +/- 0.19 vs 1.06 +/- 0.10 mmol/L, P less than 0.0008), and apo A1 (1.57 +/- 0.06 vs 1.32 +/- 0.06 g/L, P less than 0.0002) decreased, whereas LDL-C and apo B showed a biphasic behavior: they significantly fell during the first 3 wk, but during the last weeks returned to their initial values.

Local haemofiltration with free radical scavenger treatment during revascularisation of severe muscular ischaemia induced in sheep limbs

Many treatments have been proposed for the prevention of the revascularisation syndrome following embolectomy or thrombectomy in patients with severe ischaemia. These include the administration of diuretics, bicarbonate, buffer solutions, free radical scavengers, washing out the venous blood from the ischaemic leg, or systemic dialysis. The aim of our study was to investigate the effect of combining haemofiltration with a treatment using compound oxy-radical scavengers in order to prevent or to reduce the appearance of the revascularisation syndrome. The study was performed on 13 sheep. Eight animals underwent 4 h of aortic and vena cava occlusion using irrigation-occlusion catheters, followed by normal reperfusion (control group). Five sheep underwent the same period of ischaemia, followed by 1 h of local haemofiltration and re-oxygenation and 2 h of normal revascularisation. The priming solution for the ECC circuit consisted of 500 ml of 20% mannitol and 500 ml of 18/1000 HCO3- contained: superoxide dismutase (150,000 I.U.), methylprednisolone, 1 g, and heparin, 10,000 I.U. After the 3rd h of ischaemia, 2.1 g of acetate alpha-tocopherol (30 mg kg-1) were injected i.m. The treatment produced good protection against oxidative stress, shown by an increase in the glutathione ratio (GSH/GSSG), and reduced muscular damage, confirmed by a moderate increase in creatine phosphokinase (CPK) levels (significantly higher in the control group). Diuresis was significantly higher in the treated group, and the acid-basic and potassium balance returned to normal more rapidly. Our data suggest that this combined treatment could be effective in the prevention of the ischaemia-reperfusion syndrome.

gamma-Glutamyltransferase isoenzyme pattern in workers exposed to tetrachloroethylene

In compliance with the mandatory medical surveillance of workers exposed to tetrachloroethylene (PCE) in Italy, isoenzyme fractioning of serum gamma-glutamyltransferase (GGT) was performed on 141 workers of both sexes and on 130 control subjects. None of the workers showed any clinical symptoms of liver disease and their enzymatic profiles, including AST, ALT, 5'-NU, ALP, and GGT, were within the normal reference limits. A statistically significant increase in total GGT serum level was found in the exposed subjects, which was associated with an increase in one of the two fractions normally present in healthy individuals (GGT-2), as well as with the appearance and progressive increase of the level of a fraction (GGT-4) considered to be an expression of hepato-biliary impairment. Further research is ongoing among these workers, which will clarify whether or not electrophoretic GGT tests may be useful in detecting liver function changes due to occupational exposure to PCE.

Analysis of B10.D2 recombinant congenic mouse strains shows that audiogenic and beta-CCM-induced seizures depend on different genetic mechanisms

The rate of occurrence of audiogenic seizures and seizures induced by the benzodiazepine receptor inverse agonist methyl-beta-carboline-3-carboxylate (beta-CCM) were analyzed in several recombinant congenic strains of mice bred from B10.D2 and DBA/2J. Although both types of seizures have similar behavioral patterns and might involve GABAergic mechanisms, no correlation was observed between the occurrence of the two types of seizures across the strains, suggesting that these two types of seizures depend on different genetic mechanisms.

Myocardial metabolic and hemodynamic effects of a sustained intravenous infusion of nifedipine with and without metoprolol in patients with unstable angina

We tested the usefulness of a sustained intravenous infusion of nifedipine and a combination of nifedipine and metoprolol in the early management of 14 patients with unstable angina pectoris. After a 24-hour run-in period, nifedipine was titrated in a stepwise fashion (mean dose 27 +/- 7 micrograms/min). After nifedipine treatment coronary blood flow increased from 150 +/- 66 to 183 +/- 74 ml/min (p less than 0.05), whereas double product, myocardial oxygen consumption, and both arterial and coronary sinus (nor)epinephrine levels were unchanged. Myocardial lactate uptake increased from 3.4 +/- 26.1 to 31.3 +/- 26.6 mumol/min (p less than 0.005) and free fatty acid uptake from 7.2 +/- 22.1 to 34.5 +/- 33.7 mumol/min (p less than 0.05). A small nonsignificant improvement in amino acid metabolism was observed. Metoprolol was added in seven patients and led to a decrease in double product (-2.2 +/- 1.6 x 10(3); p less than 0.01) and myocardial oxygen consumption (-3.2 +/- 3.8 ml/min; p less than 0.05). The lactate uptake/oxygen uptake ratio increased by 18% after metoprolol (p = NS). The number of episodes of chest pain decreased from 2.4 +/- 1.1/24 hours to 0.1 +/- 0.2 in the nifedipine group and from 2.9 +/- 1.1/24 hours to 0.3 +/- 0.5 in the nifedipine plus metoprolol group (both p less than 0.01). We conclude that in the acute phase of unstable angina, intravenous nifedipine can be carefully titrated to improve coronary blood flow and oxidative metabolism. The addition of metoprolol is also associated with a reduction in myocardial oxygen demand. This treatment results in significant hemodynamic stability.

Graft-versus-host mortality induced by noncytolytic CD4+ T cell clones specific for non-H-2 antigens

The relative contribution of individual non-H-2 Ag and of T cell subsets that initiate graft-vs-host reaction (GVHR) as well as the mechanism responsible for histopathologic lesions are still a matter of debate. To address these questions and to favor the selection of T cells primed in vivo against non-H-2 Ag important in GVHR we derived T cell clones from spleens of (DBA/2 x B10.D2)F1 (H-2d) mice developing this reaction after the graft of B10.D2 (H-2d) cells incompatible for numerous non-H-2 Ag plus Mlsa. The pattern of reactivity of eight selected clones against cells from different strains of mice including (BXD)RI strains indicated that one CD4+ clone is specific for Mlsa and seven additional clones (six CD4+ and one CD8+) are specific for four different non-H-2 Ag (Ag.I-IV) and proliferate in an H-2-restricted manner. The same series of experiments suggested that Ag.I and II are poorly polymorphic and allowed to propose the localisation of the genes controlling Ag.I (chromosome 1) and Ag.III (chromosome 4). All the clones show a triple (alpha, beta, gamma) mRNA transcript for TCR but at their surface they express the alpha/beta-heterodimer. The clone specific for Mlsa expresses V beta 6 and that specific for Ag.IV expresses V beta 8.1. Rapid mortality accompanied by clinical and histologic signs of severe GVHR was observed after administration of CD4+ clones (together with host-syngeneic bone marrow) derived early after grafting and specific for Ag.I and II but not after administration of: 1) CD8+ cytolytic clone derived early after grafting and specific for Ag.IV; 2) CD4+ clones derived late after grafting and specific for Ag.III; and 3) CD4+ clone specific for Mlsa. A clear correlation was established between the capacity of CD4+ clones to induce GVHR mortality, to mediate host-specific DTH and to release a high level of TNF. In conclusion: 1) the reaction against a single non-H-2 Ag is sufficient to provoke lethal GVHR; 2) the capacity to provoke GVHR mortality depends on antigenic specificity and functional properties of the responding clones; 3) the inflammatory process mediated by CD4+ clones may play a major role whereas the specific CD8+ T cell-mediated cytolytic activity is not necessarily lethal.

Graft-versus-host mortality induced by noncytolytic CD4+ T cell clones specific for non-H-2 antigens

The relative contribution of individual non-H-2 Ag and of T cell subsets that initiate graft-vs-host reaction (GVHR) as well as the mechanism responsible for histopathologic lesions are still a matter of debate. To address these questions and to favor the selection of T cells primed in vivo against non-H-2 Ag important in GVHR we derived T cell clones from spleens of (DBA/2 x B10.D2)F1 (H-2d) mice developing this reaction after the graft of B10.D2 (H-2d) cells incompatible for numerous non-H-2 Ag plus Mlsa. The pattern of reactivity of eight selected clones against cells from different strains of mice including (BXD)RI strains indicated that one CD4+ clone is specific for Mlsa and seven additional clones (six CD4+ and one CD8+) are specific for four different non-H-2 Ag (Ag.I-IV) and proliferate in an H-2-restricted manner. The same series of experiments suggested that Ag.I and II are poorly polymorphic and allowed to propose the localisation of the genes controlling Ag.I (chromosome 1) and Ag.III (chromosome 4). All the clones show a triple (alpha, beta, gamma) mRNA transcript for TCR but at their surface they express the alpha/beta-heterodimer. The clone specific for Mlsa expresses V beta 6 and that specific for Ag.IV expresses V beta 8.1. Rapid mortality accompanied by clinical and histologic signs of severe GVHR was observed after administration of CD4+ clones (together with host-syngeneic bone marrow) derived early after grafting and specific for Ag.I and II but not after administration of: 1) CD8+ cytolytic clone derived early after grafting and specific for Ag.IV; 2) CD4+ clones derived late after grafting and specific for Ag.III; and 3) CD4+ clone specific for Mlsa. A clear correlation was established between the capacity of CD4+ clones to induce GVHR mortality, to mediate host-specific DTH and to release a high level of TNF.

IN CONCLUSION

1) the reaction against a single non-H-2 Ag is sufficient to provoke lethal GVHR; 2) the capacity to provoke GVHR mortality depends on antigenic specificity and functional properties of the responding clones; 3) the inflammatory process mediated by CD4+ clones may play a major role whereas the specific CD8+ T cell-mediated cytolytic activity is not necessarily lethal.

Therapeutic techniques vs therapeutic relationships in child behavior therapy

The parents of 56 children who had received behavior therapy rated a number of variables, including the degree to which they viewed the therapeutic relationship versus the specific techniques used in treatment as important, the extent to which the child improved in therapy, and the child's present functioning. Therapists also provided ratings of clinical improvement. Even though parents gave the highest ratings for the importance of the relationship in therapy, the correlation between technique and clinical outcome was statistically significant while the correlations between the relationship and outcome was not. These statistical associations also held when therapists rated improvement. Also, therapists saw greater improvement in children than did the parents. Over-all, the results support the view that the relationship and techniques are interwoven and are both perceived as important factors in treatment.