Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment.

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment.

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Interobserver variation in the classification of thymic tumours--a multicentre study using the WHO classification system.

AIMS: To test the reproducibility of the current World Health Organization (WHO) classification of thymic epithelial tumours and to determine the level of interobserver variation within a group of pathologists, all with experience and expertise in thoracic pathology. METHODS AND RESULTS: Ninety-five thymic tumours were circulated to a group of 17 pathologists in the UK and The Netherlands over a 1-year period. Participants were asked to classify them according to WHO criteria. The diagnoses were subjected to statistical analysis and kappa values calculated. The overall level of agreement was moderate (kappa 0.45). When the categories were reduced in number by creating two groups, (A + AB + B1 + B2 and B3 + C), the level of agreement increased to 0.62. An alternative grouping (A + AB + B1 and B2 + B3 + C) increased it slightly further. The best agreement was in tumour types A and AB. Difficulties arose in distinguishing B1 tumours from B2 tumours and B2 tumours from B3 tumours. CONCLUSIONS: Although the WHO system describes a number of well-defined tumour types with clear diagnostic criteria, the overall level of agreement was moderate and improved if some groups were amalgamated.

Segmental pulmonary veno-occlusive disease secondary to lung cancer.

This report describes two cases of segmental pulmonary vein occlusion secondary to lung malignancy in which lung biopsies showed histological features of veno-occlusive disease. These are the first cases to be reported in the literature in which such lung parenchymal histological changes are described in association with lung malignancy.

Low-grade B-cell lymphoma of mucosa-associated lymphoid tissue arising in the thymus. A thymic lymphoma mimicking myoepithelial sialadenitis.

We describe two cases of primary low-grade B-cell lymphoma of the thymus that showed histological features of low-grade B-cell lymphoma arising in mucosa-associated lymphoid tissue (MALT). The appearances most closely resembled MALT lymphoma arising in myoepithelial sialadenitis (MESA). In both cases, the tumor was excised. In one case, there has been no recurrence in 4 years of follow-up without further treatment; in the second case, the tumor has involved an axillary lymph node. Immunohistochemistry showed light-chain restriction in both cases, and the B-cell phenotype was similar to that previously described in MALT lymphomas. The occurrence of MALT lymphoma in the thymus is consistent with the presence of mucosal structures (Hassall's corpuscles) and with recent descriptions of a native B-cell population in this organ. The relationship of this previously undescribed thymic low-grade B-cell MALT lymphoma arising in the thymus has not yet been clarified.

Thymolipoma in association with Hodgkin's disease.

Thymolipomas are rare mediastinal tumors. They have been described with a variety of systemic diseases. To our knowledge they have never been described in association with Hodgkin's disease. The significance of this association is unknown.

Epithelial hyperplasia and malignant change in congenital lung cysts.

Patients with congenital lung cysts are at increased risk of developing carcinoma, but the mechanisms concerned are not clear. The case of a young adult who developed a bronchioloalveolar carcinoma associated with a cystic congenital adenomatoid malformation is reported. The adjacent lung showed an unusual intra-alveolar hyperplasia of mucous cells. Two further cases of congenital adenomatoid malformation are also described; both patients presented in infancy and showed similar mucous cell hyperplasia in alveoli surrounding the cysts. In all three cases the staining characteristic of the mucus was identical with that of normal bronchial mucous glands. It is suggested that the benign proliferation represents a premalignant lesion. Its presence in infants shows that it may occur at an early age and reinforces the need for early removal of congenital lung cysts.

Immunohistochemistry in the distinction between malignant mesothelioma and pulmonary adenocarcinoma: a critical evaluation of new antibodies.

AIM: The value of immunohistochemical staining in differentiating between malignant mesothelioma and pulmonary adenocarcinoma was re-examined using newly available commercial antibodies, with the aim of increasing the sensitivity and specificity of diagnosis, and simplifying the antibody panel required. METHODS: Forty one malignant mesotheliomas and 35 lung adenocarcinomas were studied. Commercial antibodies to calretinin, E-cadherin, N-cadherin, surfactant apoprotein A (SP-A), thyroid transcription factor 1 (TTF-1), thrombomodulin, and cytokeratin 5/6 were applied using the streptavidin-biotin-peroxidase complex procedure on formalin fixed, paraffin wax embedded tissue. RESULTS: E-cadherin was expressed in all adenocarcinomas and in 22% of the mesotheliomas. TTF-1 expression was detected in 69% of the adenocarcinomas and none of the mesotheliomas. Positive staining with polyclonal anticalretinin was detected in 80% of the mesotheliomas and 6% of the adenocarcinomas. N-cadherin was expressed in 78% of mesotheliomas and 26% of adenocarcinomas. Thrombomodulin was expressed in 6% of the adenocarcinomas and in 53% of the mesotheliomas. Cytokeratin 5/6 expression was detected in 6% of the adenocarcinomas and 63% of the mesotheliomas. The results were compared with the standard laboratory panel for mesothelioma diagnosis: anticarcinoembryonic antigen (anti-CEA), LeuM1, BerEP4, and HBME-1. CONCLUSION: Of the antibodies used in this study, E-cadherin was 100% sensitive for pulmonary adenocarcinoma and TTF-1 was 100% specific for pulmonary adenocarcinoma. The application of these two antibodies alone was adequate for the diagnosis of 69% of adenocarcinomas and 78% of mesotheliomas. Where TTF-1 is negative and E-cadherin is positive, a secondary panel of antibodies, including BerEP4 and LeuM1 (CD15) and antibodies directed against CEA, calretinin, cytokeratin 5/6, thrombomodulin, and N-cadherin, is required for differentiation between malignant mesothelioma and pulmonary adenocarcinoma.

The role and histological classification of needle core biopsy in comparison with fine needle aspiration cytology in the preoperative assessment of impalpable breast lesions.

AIMS: To investigate the role of needle core biopsy (NCB) in the preoperative assessment of impalpable breast lesions, mainly derived from the NHS Breast Screening Programme (NHSBSP) and to assess our own modifications to a suggested system for the classification of breast NCBs. METHODS: The NCB, fine needle aspiration cytology (FNAC), and radiology scores from 298 women with non-palpable breast lesions presenting between January 1997 and December 1998, together with the open biopsy results (where available) were collated and analysed. RESULTS: The mean follow up period was 15.8 months (range, 5-28). The 298 NCB specimens were categorised as follows: unsatisfactory/non-representative (B1; n = 61; 20.5%), benign but uncertain whether representative (B2r; n = 52; 17.4%), benign (B2; n = 103; 34.6%), lesions possibly associated with malignancy but essentially benign (B3a; n = 9; 3.0%), atypical epithelial proliferations (B3b; n = 10; 3.4%), suspicious of malignancy (B4; n = 7; 2.3%), and malignant (B5; n = 56; 18.7%). Excision biopsy was performed in 43 cases within the B1 (n = 19), B2r (n = 8), B2 (n = 8), and the B3a (n = 8; data unavailable in one case) categories, revealing malignancy in 18 (42.8%) cases and in 65 cases within the B3b, B4, and B5 categories, revealing malignancy in 64 cases (98.5%). The sensitivity of NCB for malignancy was 87.7%, with a specificity and positive predictive value of 99.3% and 98.5%, respectively. FNAC had an inadequacy rate of 58.7%, a complete sensitivity of 34.5% and a specificity of 47.6%. CONCLUSIONS: This study confirms the value of NCB in the preoperative assessment of impalpable breast lesions. Two new categories are suggested for the NCB classification; category B2r for benign breast tissue where representativeness is uncertain, and the subdivision of category B3 into B3a for benign lesions potentially associated with malignancy (for example, radial scars and intraduct papillomas) and B3b for more worrisome atypical epithelial proliferations. These will aid the accurate audit of NCB and identify more clearly the intellectual pathway leading to a particular assessment.

Pulmonary involvement in systemic sclerosis: the detection of early changes by thin section CT scan, bronchoalveolar lavage and 99mTc-DTPA clearance.

Systemic sclerosis is frequently complicated by fibrosing alveolitis although clinical and radiological abnormalities are not usually apparent until the lung disease is well established. The aim of this study was to investigate pulmonary involvement in systemic sclerosis by thin section CT scan, bronchoalveolar lavage (BAL) and 99mTc-DTPA clearance studies, and assess the value of these tests in defining pulmonary abnormalities in patients with a normal chest radiograph. Patients were divided into those with an abnormal chest radiograph (Group I, n = 14) and those with a normal chest radiograph (Group II, n = 16). CT scans were abnormal in all patients in Group I and 7 of 16 (44%) in Group II. BAL inflammatory cell counts were raised in all 12 (100%) patients studied in Group I and 11 of 15 (73%) in Group II. There was no difference in the type of inflammatory cells observed between the two groups. 99mTc-DTPA clearance was faster than normal controls in ten of 14 patients (71%) in Group I and seven of 15 (47%) in Group II and correlated with carbon monoxide transfer factor (P less than 0.05). Lung biopsies were performed on nine patients in Group I and three in Group II all of whom had abnormal CT scans. Fibrosing alveolitis was confirmed in every case. Group II biopsies could not be distinguished from Group I biopsies; both showed fibrosis as well as inflammation suggesting that pulmonary fibrosis is an early abnormality in systemic sclerosis. Our results indicate that CT scans, BAL and 99mTc-DTPA are frequently abnormal in asymptomatic patients with systemic sclerosis who have normal chest radiographs. When the CT scan is normal abnormalities of BAL and/or 99mTc-DTPA (99mTechnetium diethylenetriamine pentacetate) clearance may indicate lung disease at a still earlier stage. This observation requires further investigation.

Changes in vein interstitium following distension for aortocoronary bypass.

Some patients who undergo aortocoronary bypass develop lesions in the graft and recurrence of symptoms. Hydraulic distension is used for preparation of veins. We have studied properties of vein interstitium, before and after peroperative distension, in 30 consecutive unselected patients. Segments of vein were studied for water content, swelling behaviour, tracer distribution, and uronic acid content. Initial water content was the same in distended and undistended vein; initial uronic acid content was slightly lower in distended veins, 8.7 (SD = 2.3) micrograms/m, n = 4 vs 10.5 (SD = 5.1) micrograms/mg dry weight, n = 6, not significant. The initial ratio, uronate/hydroxyproline was less in distended veins, 0.14 (SD = 0.05) n = 4 vs 0.19 (SD = 0.07), n = 6 in controls, not significant. Distended veins swelled less during incubation in saline. Average weight gain/initial weight was 0.65 (SD = 0.45), n = 27, and 1.1 (SD = 0.66), n = 25 in controls (p less than 0.01); change in water content/dry weight was 1.2 (SD = 1.1), n = 22, and 1.7 (SD = 1), n = 23 (p less than 0.02), in controls. Distended veins desorbed less uronic acid into the bath; 0.40 (SD = 0.2) microgram/mg wet tissue, n = 26 and 0.59 (SD = 0.3), n = 25 in controls (p less than 0.01). The pattern of uptake of two tracers 125I Serum albumin and 51Cr EDTA, was similar in both groups. These findings suggest alteration of the interstitial matrix of veins during distension. Histologic examination of glutaraldehyde-fixed tissue by light and electron microscopy revealed mural thinning and endothelial cell damage in distended veins.(ABSTRACT TRUNCATED AT 250 WORDS)

Papillary mesothelioma of ovary.

A case of primary papillary mesothelioma of the ovary is reported and its microscopic and ultrastructural features described. This tumour was an incidental surgical finding and was accompanied by multiple, partially cystic, peritoneal lesions with similar microscopic features. The histological pattern was predominantly papillary with well-differentiated mesothelial cells and a prominent stromal infiltrate that included large numbers of lymphocytes and lipid-filled macrophages. A comparison is made with adenomatoid tumours and with other tumours of ovarian epithelium and it is suggested that this tumour may represent the benign counterpart of one form of clear cell carcinoma of the ovary. The presence of multiple peritoneal lesions may indicate limited malignant potential comparable to some other papillary epithelial neoplasms of the ovary.

Large cell lymphoma of the mediastinum: a B-cell tumour of probable thymic origin.

Fifteen cases of non-Hodgkin's lymphoma of the anterior mediastinum are reported. In the first group of four, fresh tissue was available and immunohistochemical studies demonstrated their B-cell origin, with monotypic immunoglobulin production in two. Only fixed tissue was available in the second group of 11 patients. All stained with antibody to leucocyte common antigen (PD7/26) and three showed monotypic immunoglobulin production. If the two groups are combined seven of the 15 tumours were clearly of B-cell origin. Classification on morphological grounds was difficult, with most tumours showing mixtures of centroblasts and large centrocytes, and the original diagnoses had included Hodgkin's disease (three), thymoma (one) and undifferentiated carcinoma (two). None of the patients had evidence of extra-thoracic disease at presentation and when this developed the organs involved were liver (one), kidney (two) and thyroid (one). Direct extension within the chest led to infiltration of chest wall, sternum, lung, superior vena cava and other structures. The site of origin, lack of nodal involvement and, in one case, presence of residual thymus around the tumour indicate an origin in thymic B-cells.

Pulmonary blastoma, carcinosarcoma and spindle-cell carcinoma: an immunohistochemical study of keratin intermediate filaments.

We have examined 18 primary malignant lung tumours categorized as either carcinosarcoma, blastoma or spindle-cell carcinoma according to accepted criteria. Two monoclonal antibodies to keratins, CAM 5.2 and LP 34, were used to determine whether the non-epithelial or spindle-cell components of each tumour showed evidence of keratin expression. By this means the epithelial nature of the five tumours classified as spindle-cell carcinomas was confirmed. In all four pulmonary blastomas and in five of nine carcinosarcomas, the sarcomatous elements failed to stain for keratin but in the remaining four carcinosarcomas there was focal staining. The histogenesis of these tumours is discussed and it is suggested that the sarcomatous component of a carcinosarcoma may be derived from malignant epithelial cells by a process of mesenchymal metaplasia with a switch in intermediate filament type. It remains uncertain whether blastomas are derived from both endoderm and mesoderm, or from either one of these tissues, with one component representing complete metaplastic transformation.

Thymoma: an integrated clinicopathological and immunohistochemical study.

The clinicopathological features of 32 thymomas were reviewed and tumours were staged according to their degree of invasion. Their antigenic profiles were studied using monoclonal antibodies to cytokeratins (CAM 5.2 and DAKO-CK1), HNK-1 (Leu 7), and HLA-DR (TAL-IB5). Stage I (non-invasive) tumours were mainly of the spindle cell (SC) or predominantly lymphocytic (PL) types, whilst all the predominantly epithelial (PE) tumours were either locally invasive (stage II) or showed more extensive spread (stage III). Neoplastic epithelial cells all expressed cytokeratin, but varied in their degree of positivity. CAM 5.2 was more uniformly positive with cells at the periphery of tumour nodules and lining tubulo-cystic areas staining most strongly. DAKO-CK1 gave less uniform positivity but highlighted areas of medullary differentiation. HNK-1 was variably expressed in all tumour groups but was found more often in the invasive tumours (73 per cent stage III, 62 per cent stage II, 50 per cent stage I), particularly those of PE or mixed (M) type. In general, TAL-IB5 expression was lost in the more invasive thymomas. Focal medullary differentiation in tumours suggests a common origin for cortical and medullary epithelium, indicating that sub-division of tumours into cortical or medullary types is not valid. Immunohistochemistry may usefully complement clinical and macroscopic findings in the assessment of malignancy in thymoma.

Secretory component in pulmonary adenocarcinoma and mesothelioma.

The distribution of secretory component was examined by an immunoperoxidase method in 40 pulmonary adenocarcinomas, 11 malignant pleural mesotheliomas and areas of normal lung adjacent to the tumours. Secretory component was demonstrated in tumour cells in 25 (67%) adenocarcinomas. Its presence correlated with the degree of differentiation but was not related to tumour pattern. In the normal lung secretory component can be demonstrated in bronchial ciliated cells, bronchial gland serous cells, bronchiolar epithelium and hyperplastic alveolar epithelium. Although not usually detectable in normal mucous cells it was frequently present in mucin-producing tumours. None of the mesotheliomas examined contained secretory component and this may be an additional useful feature in the differential diagnosis between mesothelioma and adenocarcinoma.

Histopathology of the pleura.

This review attempts to provide up to date information on structure/function relationships of the pleura and on the pathology of pleural effusions, pneumothorax, pleural repair, pleural infections, pleural involvement in systemic connective tissue disorders, non-malignant asbestos-induced pleural disease, mesothelioma and other pleural tumours.