Proline restores mitochondrial function and reverses aging hallmarks in senescent cells

Mitochondrial dysfunction is a hallmark of cellular senescence, with the loss of mitochondrial function identified as a potential causal factor contributing to senescence-associated decline in cellular functions. Our recent findings revealed that ectopic expression of the pluripotency transcription factor NANOG rejuvenates dysfunctional mitochondria of senescent cells by rewiring metabolic pathways. In this study, we report that NANOG restores the expression of key enzymes, PYCR1 and PYCR2, in the proline biosynthesis pathway. Additionally, senescent mesenchymal stem cells manifest severe mitochondrial respiratory impairment, which is alleviated through proline supplementation. Proline induces mitophagy by activating AMP-activated protein kinase α and upregulating Parkin expression, enhancing mitochondrial clearance and ultimately restoring cell metabolism. Notably, proline treatment also mitigates several aging hallmarks, including DNA damage, senescence-associated β-galactosidase, inflammatory cytokine expressions, and impaired myogenic differentiation capacity. Overall, this study highlights the role of proline in mitophagy and its potential in reversing senescence-associated mitochondrial dysfunction and aging hallmarks.

Skeletal muscle reprogramming enhances reinnervation after peripheral nerve injury

Peripheral Nerve Injuries (PNI) affect more than 20 million Americans and severely impact quality of life by causing long-term disability. The onset of PNI is characterized by nerve degeneration distal to the nerve injury resulting in long periods of skeletal muscle denervation. During this period, muscle fibers atrophy and frequently become incapable of "accepting" innervation because of the slow speed of axon regeneration post injury. We hypothesize that reprogramming the skeletal muscle to an embryonic-like state may preserve its reinnervation capability following PNI. To this end, we generated a mouse model in which NANOG, a pluripotency-associated transcription factor can be expressed locally upon delivery of doxycycline (Dox) in a polymeric vehicle. NANOG expression in the muscle upregulated the percentage of Pax7+ nuclei and expression of eMYHC along with other genes that are involved in muscle development. In a sciatic nerve transection model, NANOG expression led to upregulation of key genes associated with myogenesis, neurogenesis and neuromuscular junction (NMJ) formation, and downregulation of key muscle atrophy genes. Further, NANOG mice demonstrated extensive overlap between synaptic vesicles and NMJ acetylcholine receptors (AChRs) indicating restored innervation. Indeed, NANOG mice showed greater improvement in motor function as compared to wild-type (WT) animals, as evidenced by improved toe-spread reflex, EMG responses and isometric force production. In conclusion, we demonstrate that reprogramming the muscle can be an effective strategy to improve reinnervation and functional outcomes after PNI.

Wnt/BMP Mediated Metabolic Reprogramming Preserves Multipotency of Neural Crest-Like Stem Cells

Neural crest-like stem cells resembling embryonic neural crest cells (NCs) can be derived from adult human tissues such as the epidermis. However, these cells lose their multipotency rapidly in culture limiting their expansion for clinical use. Here, we show that the multipotency of keratinocyte-derived NCs (KC-NCs) can be preserved by activating the Wnt and BMP signaling axis, promoting expression of key NC-specifier genes and ultimately enhancing their differentiation potential. We also show that transcriptional changes leading to multipotency are linked to metabolic reprogramming of KC-NCs to a highly glycolytic state. Specifically, KC-NCs treated with CHIR and BMP2 rely almost exclusively on glycolysis for their energy needs, as seen by increased lactate production, glucose uptake, and glycolytic enzyme activities. This was accompanied by mitochondrial depolarization and decreased mitochondrial ATP production. Interestingly, the glycolytic end-product lactate stabilized β-catenin and further augmented NC-gene expression. Taken together, our study shows that activation of the Wnt/BMP signaling coordinates the metabolic demands of neural crest-like stem cells governing decisions regarding multipotency and differentiation, with possible implications for regenerative medicine.

Reversine ameliorates hallmarks of cellular senescence in human skeletal myoblasts via reactivation of autophagy

Cellular senescence leads to the depletion of myogenic progenitors and decreased regenerative capacity. We show that the small molecule 2,6-disubstituted purine, reversine, can improve some well-known hallmarks of cellular aging in senescent myoblast cells. Reversine reactivated autophagy and insulin signaling pathway via upregulation of Adenosine Monophosphate-activated protein kinase (AMPK) and Akt2, restoring insulin sensitivity and glucose uptake in senescent cells. Reversine also restored the loss of connectivity of glycolysis to the TCA cycle, thus restoring dysfunctional mitochondria and the impaired myogenic differentiation potential of senescent myoblasts. Altogether, our data suggest that cellular senescence can be reversed by treatment with a single small molecule without employing genetic reprogramming technologies.

Inhibition of glutaminolysis restores mitochondrial function in senescent stem cells

Mitochondrial dysfunction, a hallmark of aging, has been associated with the onset of aging phenotypes and age-related diseases. Here, we report that impaired mitochondrial function is associated with increased glutamine catabolism in senescent human mesenchymal stem cells (MSCs) and myofibroblasts derived from patients suffering from Hutchinson-Gilford progeria syndrome. Increased glutaminase (GLS1) activity accompanied by loss of urea transporter SLC14A1 induces urea accumulation, mitochondrial dysfunction, and DNA damage. Conversely, blocking GLS1 activity restores mitochondrial function and leads to amelioration of aging hallmarks. Interestingly, GLS1 expression is regulated through the JNK pathway, as demonstrated by chemical and genetic inhibition. In agreement with our in vitro findings, tissues isolated from aged or progeria mice display increased urea accumulation and GLS1 activity, concomitant with declined mitochondrial function. Inhibition of glutaminolysis in progeria mice improves mitochondrial respiratory chain activity, suggesting that targeting glutaminolysis may be a promising strategy for restoring age-associated loss of mitochondrial function.

National audit of seven-day working care in radiology

Objectives

To evaluate the extent to which our current provision of diagnostic and interventional radiology services matches existing clinical demand and future government proposals as set out in the Royal College of Radiologists published guidance on providing seven-day acute care.

Methods

In June 2018, all UK radiology department audit leads were sent a questionnaire designed to assess compliance for each standard of the Royal College of Radiologists published guidance on providing seven-day acute care.

Results

135 hospitals (68%) responded. Of those that responded, 96% of departments have a diagnostic radiologist rota for clinicians to discuss acute cases and review imaging and 48% of departments do not have a fully staffed consultant rota 24 h a day, seven days a week for interventional radiology. There is significant variance in MRI radiographer availability within departments, ranging from 18.8% during Saturday/Sunday evening/overnight up to a maximum of 63.9% during Saturday daytime. 11% of departments participate in a regional out of hours cross-organisation reporting rota. 40% of departments have no 24/7 RIS technical support and 34% have no PACS technical support out of hours.

Conclusion

There is a wide variation in practice across radiology departments in the UK. Although there are some standards that the majority of hospitals are achieving, there is a significant short-fall in fundamental aspects of providing acute seven-day care. The multifactorial nature in which these problems have arisen means there is no easy solution to combat these issues. There is a requirement for significant investment and political commitment to improve staffing and infrastructure in order to address the current situation.

Advances in knowledge

A UK wide evaluation of the current provision of seven-day working in radiology showing 54% of hospitals do not have a UK working-time regulations compliant Interventional radiology rota, severe lack of availability of acute MRI out of hours and significant deficiencies in providing technical support out of hours. A sustainable and efficient seven-day service is currently not being provided.

Adult tissue-derived neural crest-like stem cells: Sources, regulatory networks, and translational potential

Neural crest (NC) cells are a multipotent stem cell population that give rise to a diverse array of cell types in the body, including peripheral neurons, Schwann cells (SC), craniofacial cartilage and bone, smooth muscle cells, and melanocytes. NC formation and differentiation into specific lineages takes place in response to a set of highly regulated signaling and transcriptional events within the neural plate border. Premigratory NC cells initially are contained within the dorsal neural tube from which they subsequently emigrate, migrating to often distant sites in the periphery. Following their migration and differentiation, some NC‐like cells persist in adult tissues in a nascent multipotent state, making them potential candidates for autologous cell therapy. This review discusses the gene regulatory network responsible for NC development and maintenance of multipotency. We summarize the genes and signaling pathways that have been implicated in the differentiation of a postmigratory NC into mature myelinating SC. We elaborate on the signals and transcription factors involved in the acquisition of immature SC fate, axonal sorting of unmyelinated neuronal axons, and finally the path toward mature myelinating SC, which envelope axons within myelin sheaths, facilitating electrical signal propagation. The gene regulatory events guiding development of SC in vivo provides insights into means for differentiating NC‐like cells from adult human tissues into functional SC, which have the potential to provide autologous cell sources for the treatment of demyelinating and neurodegenerative disorders.

Does elastography reduce the need for thyroid FNAs?

OBJECTIVE

Ultrasound elastography (USE) assesses lesion stiffness by evaluating tissue distortion in response to stress; it is emerging as a potentially useful tool to augment the ultrasound characterisation of thyroid nodules. The aim of this study was to assess the accuracy of USE examination of thyroid nodules compared with pathological outcome, especially to determine whether USE could reliably detect benign nodules and reduce the numbers of ultrasound guided fine needle aspiration cytology (USgFNAC).

DESIGN

Over a three-year period, thyroid nodules were initially characterised by B-mode ultrasound (US) findings. Where USgFNAC was indicated by clinical concern and/or the sonographic appearances, the lesion was then subjected to USE by an experienced operator prior to the USgFNAC.

PATIENTS

147 thyroid nodules were examined by USE and USgFNAC in 146 patients.

MEASUREMENTS

The elastographic appearance was subjectively categorized at the time of the examination (soft, intermediate or hard) and subsequently compared with the cytological/histological outcome.

RESULTS

A total of 122 nodules were non-neoplastic, 5 nodules were benign neoplasms, 10 nodules had indeterminate cytology and 10 were malignant neoplasms. The sensitivity of USE for malignancy was 90.0%, specificity was 79.6%, PPV was 24.3%, NPV was 99.1% and accuracy was 80.3%.

CONCLUSION

Thyroid nodules that are soft at USE have a high likelihood of being non-neoplastic and subjective USE assessment of thyroid nodules by an experienced operator can be a useful means of avoiding USgFNAC for benign nodules. In contrast, we suggest that all nodules that are intermediate or hard on USE undergo USgFNAC.

Differential regulation of free radicals (reactive oxygen and nitrogen species) by contact allergens and irritants in human keratinocyte cell line

Immune responses to chemicals resulting in sensitization and the appearance of allergic responses following subsequent exposures are dependent upon activation of T lymphocytes. On the contrary, irritant responses are independent of immune response. The aim of this project was to identify the differential signaling cascade operated in allergic and irritant contact dermatitis. Recently, we have shown that keratinocyte cell line A431 can function as an antigen presenting cell (APC) and hence can be used as a model to differentiate between an allergen and irritant molecule. Allergen- and irritant-induced regulation of reactive oxygen species (ROS) and nitric oxide (NO) has been explored. Irritants induce release of ROS even at noncytotoxic concentration. ROS generation by allergens was not detected at nontoxic concentration but as the concentration was increased to a toxic dose there was a drastic increase in the ROS level compared to the untreated cells. Hence, the regulation of ROS is not significant in allergic responses but important in irritant responses. The major difference exists in the fact that the source of ROS for irritants is mitochondria, while that of allergens is mostly cytosolic. Antioxidant-induced protection from irritant-induced cell death has also been demonstrated. NO level was found to increase by allergens and irritants in a concentration-dependent manner. Hence, the regulation of ROS and NO can be used as important mediators in contact allergic and irritant dermatitis.

EMMPRIN is secreted by human uterine epithelial cells in microvesicles and stimulates metalloproteinase production by human uterine fibroblast cells

Endometrial remodeling is a physiological process involved in the gynecological disease, endometriosis. Tissue remodeling is directed by uterine fibroblast production of matrix metalloproteinases (MMPs). Several MMPs are regulated directly by the protein extracellular matrix metalloproteinase inducer (EMMPRIN) and also by proinflammatory cytokines such as interleukin (IL)1-α/β. We hypothesized that human uterine epithelial cells (HESs) secrete intact EMMPRIN to stimulate MMPs. Microvesicles from HES cell-conditioned medium (CM) expressed intact EMMPRIN protein. Treatment of HES cells with estradiol or phorbyl 12-myristate-13-acetate increased the release of EMMPRIN-containing microvesicles. The HES CM stimulated MMP-1, -2, and -3 messenger RNA levels in human uterine fibroblasts (HUFs) and EMMPRIN immunodepletion from HES-cell concentrated CM reduced MMP stimulation (P < .05). Treatment of HUF cells with low concentrations of IL-1β/α stimulated MMP production (P < .05). These results indicate that HES cells regulate MMP production by HUF cells by secretion of EMMPRIN, in response to ovarian hormones, proinflammatory cytokines as well as activation of protein kinase C.

Waterpipe tobacco and cigarette smoking among university students in Jordan

SETTING

While waterpipe and cigarette smoking have been well studied in Syria and Lebanon, data from Jordan are limited.

OBJECTIVES

To characterize the relative prevalence of waterpipe tobacco and cigarette smoking among university students in Jordan, and to compare the demographic and environmental factors associated with each form of tobacco use.

DESIGN

We surveyed 1845 students randomly recruited from four universities in Jordan. We used multivariable logistic regression controlling for clustering of individuals within universities to determine associations between demographic and environmental covariates and waterpipe tobacco and cigarette use.

RESULTS

Waterpipe tobacco smoking rates were 30% in the past 30 days and 56% ever, while cigarette smoking rates were 29% in the past 30 days and 57% ever. Past 30-day waterpipe tobacco smoking rates were 59% for males and 13% for females. Females had substantially lower odds than males of being current waterpipe (OR 0.12, 95%CI 0.10-0.15) or cigarette (OR 0.08, 95%CI 0.05-0.14) smokers. Current cigarette smoking was more significantly associated with markers of high socio-economic status (SES) than waterpipe tobacco smoking.

CONCLUSION

Waterpipe tobacco smoking is as common as cigarette smoking among Jordanian university students. While cigarette smoking is consistently associated with high SES, waterpipe tobacco smoking is more evenly distributed across various populations.

Vitamin D nutritional status of exclusively breast fed infants and their mothers

BACKGROUND

Vitamin D nutrition has a profound effect on the development of an infant. Vitamin D status of mothers and their infants are closely correlated. While hypovitaminosis D has emerged as a significant public health problem across all age groups, there is limited information of this condition in lactating mothers and their breast fed infants.

AIM

To evaluate the vitamin D status of lactating mothers and their breast fed infants.

SUBJECTS AND METHODS

180 healthy lactating mothers and exclusively breast fed infants, 2-24 weeks old, were recruited for the study. The mother-infant pairs underwent concurrent clinical, biochemical and hormonal evaluation for calcium-vitamin D-PTH axis.

RESULTS

The mean serum 25(OH)D values in lactating mothers was 27.2 +/- 14.6 nmol/l (10.9 +/- 5.8 ng/ml), while that of their infants was 28.9 +/- 20.8 nmol/l (11.6 +/- 8.3 ng/ml). Serum 25(OH)D levels <25 nmol/l (10 ng/ml) were found in 47.8% of the mothers and 43.2% of the infants. Among these, elevated PTH levels (>54 pg/ml) were seen in 59.3% of the mothers and 69.6% of the infants. A highly significant negative correlation was found between serum 25(OH)D and PTH in mothers (r = -0.480, p = 0.01) and their infants (r = -0.431, p = 0.01). A strong positive correlation was seen of 25(OH)D levels in mother-infant pairs (r = 0.324, p = 0.001).

CONCLUSIONS

A high prevalence of vitamin D deficiency was found in lactating mothers and their exclusively breast fed infants. Infants born to mothers with hypovitaminosis D had 3.8 times higher risk of developing hypovitaminosis D as compared to those born to mothers with normal vitamin D levels.

Obstructive nephropathy and chronic kidney disease secondary to uterine leiomyomas

We present three cases of chronic kidney disease secondary to large fibroid uterus. The difficulties experienced in their clinical management and a review of literature is outlined.

Ultrasound guidance improves the adequacy of our preoperative thyroid cytology but not its accuracy

AIMS

Our thyroid cytology audit results of 1990-1995 showed an unsatisfactory rate of 43.1% and prediction of neoplasia with a sensitivity of 86.8%. Increasingly, ultrasound scan (USS)-guided core sampling for cytology is proving a valuable tool instead of freehand fine needle aspiration (FNA) or following unsatisfactory freehand FNA. We present the results of freehand FNA and USS-guided core samples for cytology in two separate patient groups in our centre.

METHODS

Patients who had a thyroid resection and preoperative thyroid cytology in our institution between 1996 and 2002 were included. The histological diagnoses were correlated with the preceding cytology results.

RESULTS

A total of 450 FNAs were performed on 394 patients. Freehand FNAs were performed for 348 (77.3%) samples and USS-guided core for 102 (22.7%) samples; 121 (26.8%) were repeat aspirates performed on 45 patients. Using aspiration cytology (AC) grading, freehand FNA was cytologically inadequate (AC0 or AC1) in 34.8% cases whereas USS-guided core was inadequate in 17.6% cases (P = 0.001). Freehand FNA (AC3, AC4, AC5) predicted neoplasia with a sensitivity of 83.2%, specificity of 46.6%, accuracy of 63.0%, positive predictive value of 56.0% and negative predictive value of 77.1%. USS-guided core sample for cytology (AC3, AC4, AC5) predicted neoplasia with a sensitivity of 93.5%, specificity of 26.0%, accuracy of 51.9%, positive predictive value of 43.9% and negative predictive value of 86.7%.

CONCLUSIONS

Although USS-guided core provides more satisfactory specimens than freehand FNA, in our centre it does not provide increased accuracy.

Galectin-3 does not reliably distinguish benign from malignant thyroid neoplasms

AIMS

To determine whether galectin-3 is a sensitive indicator of thyroid malignancy. It has been suggested as a potential marker for differentiating thyroid carcinoma from benign or non-neoplastic lesions in preoperative fine-needle aspirates (FNAs).

METHODS

Galectin-3 protein expression was assessed by immunohistochemistry in formalin-fixed thyroid tissues from 124 patients with histological diagnoses of papillary carcinoma (n = 38), follicular carcinoma (n = 19), follicular adenoma (n = 32) and dominant nodules of multinodular goitre (n = 35). Expression of galectin-3 was also assessed by Western blotting in 24 fresh thyroid tissues.

RESULTS

Galectin-3 expression was observed in the majority of carcinomas (papillary 92%; follicular 74%). However, a large proportion of follicular adenomas (72%) and multinodular goitres (57%) also expressed galectin-3. In addition, galectin-3 expression was observed in epithelial cells of normal thyroid tissue and Hashimoto's thyroiditis. Galectin-3 immunopositivity was significantly greater in papillary carcinomas than in dominant nodules or follicular adenomas (P < 0.0001, P = 0.0005, respectively). However, galectin-3 expression was no greater in follicular carcinomas than in follicular adenomas (P = 0.8735). Western blotting analysis confirmed both the specificity of the antiserum and expression of galectin-3 in multinodular goitres, follicular adenomas/carcinomas and papillary carcinomas.

CONCLUSION

The data demonstrate that galectin-3 is not a reliable immunohistochemical marker to distinguish benign from malignant thyroid follicular lesions.

Ultrasound scan-guided core sampling for diagnosis versus freehand FNAC of the thyroid gland

BACKGROUND AND AIM

Freehand fine needle aspiration cytology (FNAC) is an obligatory investigation of the thyroid nodule. Between 5.0-43.1% of FNAC samples are reported as being initially unsatisfactory. In our unit, thyroid freehand FNAs are performed with a small needle (21 or 23G). Non-dominant nodules as part of multinodular goitres, difficult to palpate nodules or nodules with previously unsatisfactory freehand FNACs are sampled under ultrasound scan (USS) guidance with the larger 20G cutting core sampling technique. We aimed to compare the satisfactory sampling rate and safety of the two different methods.

PATIENTS AND METHODS

Cytology forms were reviewed for 262 freehand FNACs and USS-guided core samples, performed in our unit over a two-year interval (1 July 1999 to 30 June 2001).

RESULTS

Ultrasound-guided core samples for cytology were unsatisfactory (AC0-1) in 19/121 (15.6%) of the cases, compared with 66/141 (46.8%) of freehand FNACs (p value = < 0.0001). Ten out of eleven patients (91%) had a satisfactory USS-guided core after an unsatisfactory freehand FNA; 7/15 patients (46.7%) had satisfactory repeat freehand FNACs following an initial unsatisfactory freehand FNAC (p value = 0.0191). There were no complications as a result of either freehand FNAC or USS-guided core sampling.

CONCLUSION

USS-guided cores provided more satisfactory samples for assessment than freehand FNACs. The USS-guided technique is safe despite the use of the larger cuffing needle. The USS-guided core sampling was also a useful tool for repeat thyroid nodule sampling after an unsatisfactory freehand FNAC.

Unusual presentation of blunt laryngeal injury with cricotracheal disruption by attempted hanging: a case report

The management of a patient with traumatic disruption of the cricotracheal junction in an attempted suicide by hanging is described. Such injury is uncommon, and many patients die at the scene; detailed radiologic imaging is rare because of the urgency of airway management. The delayed complete disruption of the major airway in this patient allowed adequate imaging and corrective management. Associated soft-tissue injuries of the great vessels of the neck are also described.

Two cases of ethylene dibromide poisoning

Ethylene dibromide (EDB) is commonly available as a liquid pesticide for use as fumigant and preservative for storage of cereals and grains in India. Accidental or suicidal ingestion is often associated with often fatal delayed sudden hepatic or renal failure. We report 2 cases of EDB poisoning in humans.

Association of human leucocyte-DR and DQ antigens in coeliac disease: a family study

BACKGROUND AND AIMS

No family studies regarding the association of coeliac disease with the human leucocyte antigen (HLA)-DQ locus are available. Moreover, no HLA studies have been carried out in coeliac disease patients from India. The aim of this study was to study the HLA class II (DR and DQ) antigens in children with coeliac disease and in their first-degree relatives.

METHODS

Fifteen children with coeliac disease and their first-degree relatives (birth parents of all the coeliac disease patients and fifteen siblings) were studied. A group of 123 healthy unrelated and ethnically matched subjects were used as controls. The HLA-DR and -DQ typing was carried out by a complement-dependent microlymphocytotoxicity assay. The transmission disequilibrium test was used for analysis of results.

RESULTS

There was no association of coeliac disease with DR phenotypes. Ninety-three per cent of patients (14/15) carried the DQ2 allele. DQ2 was transmitted in 15 of 19 informative cases (transmission probability of 79%, chi2 6.368 with 1 df, nominal P=0.012 and P value corrected for multiple test=0.035). The haplotype relative risk associated with DQ2 was 5.71 (95% confidence interval 1.71-16.28).

CONCLUSION

Coeliac disease in Indian children is predominantly associated with HLA-DQ2.

Need for liver transplantation in Indian children

BACKGROUND

Liver transplantation (LT) is the most successful and accepted mode of therapy for failing liver in children. Pediatric LT has neither been widely attempted nor its need objectively assessed in our country.

OBJECTIVE

To assess requirement of LT in children at a tertiary care hospital.

METHODS

Data of children admitted to pediatric GE services (January 1992 to June 1997) were retrospectively analyzed. Subgroups of children with acute liver disease (ALD), chronic liver disease (CLD), neonatal cholestasis syndrome (NCS) and other etiology were evaluated for need for LT according to established criteria.

RESULTS

Of the total 301 inpatients with liver diseases assessed at our center, ALD constituted 26% (n=79), CLD 35% (n=106), NCS 27% (n=82) and miscellaneous 11% (n=34). Among ALD, 19% (n=15) had FHF and 67% (n=10) qualified for LT (INR>4.0). Of CLD, LT was warranted in 13% (2/15) cases of Wilson's disease (Wilson's score > 6) and 60% of cirrhotics (n=40/66) with decompensation. NCS comprised extrahepatic biliary atresia (EHBA) in 43, choledochal cyst in 2, paucity of intralobular bile duct (PILBD) in 2, neonatal hepatitis in 23, and was of indeterminate etiology in 12 cases. Of NCS groups, LT was the only therapeutic option in 45% (n=36) of cases (EHBA 34, choledochal cyst 2). Of 34 cases of EHBA requiring LT, 32 presented after 4 months of age and other 2 children had decompensation before four months of age. Both children with choledochal cysts had decompensated liver disease. One patient of Crigler Najjar syndrome type I had kernicterus and qualified for LT.

CONCLUSION

Our data shows need for LT in 30% of children with liver diseases constituted by cirrhosis (45%), biliary atresia (38%) and FHF (11%).

Multiple lymphomatous polyposis presenting as inflammatory bowel disease

Multiple lymphomatous polyposis is a rare manifestation of primary gastrointestinal lymphoma characterized by polypoidal masses involving several segments of the gastrointestinal tract. We report a case who initially presented with features resembling inflammatory bowel disease.

Non-Hodgkin's lymphoma masquerading as empyema thoracis

Non-hodgkin's lymphoma has varied presentations. Malignant lymphoma arising in chronic pyothorax is very rare and has been reported from Japan. We report a case of non-hodgkin's lymphoma presenting as empyema thoracis.

Right hepatic artery pseudoaneurysm after laparoscopic cholecystectomy

A case of pseudoaneurysm of the right hepatic artery after laparoscopic cholecystectomy is reported. The patient presented with recurrent episodes of massive upper gastrointestinal bleeding. Diagnosed on selective angiography, the patient was treated with ligation of the right hepatic artery at laparotomy.

Phenotypic and functional heterogeneity of thymic and splenic lymphokine activated killer cells relative to ornithine sensitivity

We have previously reported the selective inhibition of cytotoxic T lymphocytes (CTL) by 10 mM ornithine (ORN) relative to natural killer (NK) cell-derived lymphokine activated killer cells (LAK). To determine if this were due to differences in the progenitor cells or the type of stimulus, we used cortisone-resistant thymocytes (CRT) as a source of mature T cells for induction of LAK and CTL, and compared the results with spleen. Thymic and splenic CTL precursors (CTLp) from C57B1/6 (B6) mice were CD8+, ASGM1-, ORN sensitive. Splenic LAK precursors (LAKp) were CD8-, ASGM1+, ORN resistant when assayed against both YAC-1 and P815 tumor targets. In contrast, CRT-derived LAKp were CD8-, ASGM1+, ORN resistant against YAC-1, whereas LAKp against P815 were CD8+, ASGM1+, ORN sensitive. ORN sensitivity was also observed among CTL and LAK in DBA/2 mice and was associated with CD8+ phenotype. Therefore, our initial observation of differential ORN sensitivity in CTL vs LAK was a function of the progenitor cells; furthermore, CD8+ cytolytic cells are ORN sensitive whether activated by antigen (CTL) or IL-2 (T-LAK).

Fine needle aspiration cytology in a case of hepatoblastoma

The cytologic features of a case of hepatoblastoma diagnosed by fine needle aspiration (FNA) in an 18-month-old female infant are described. A mass detected in the left lobe of the liver on routine examination was subjected to FNA. The distinctive cytologic findings included malignant cells in small clusters and in acinar arrangements. Some of the acinar structures had bile plugs. Fat vacuoles were present within the cytoplasm of some of the malignant cells. Immature hematopoietic cells were also present.

A computerized system for localizing sources of cardiac activation

A noninvasive method for locating a source of cardiac electrical activity is described. The data acquisition and its preliminary processing is done with the aid of a microcomputer, while lengthier calculations are done on a large computer. The method was tested on 18 patients, and the results indicate that it is reliable, and with further technical refinements it could be used in research and clinical settings.

Echocardiographic diagnosis of supravalvular aortic stenosis

The echocardiographic features of supravalvular aortic stenosis seen in a patient with valvular aortic and multiple pulmonary branch stenosis are described. Since patterns of valvular, discrete subvalvular, and supravalvular aortic stenosis can be recognized by echocardiography, it is now possible to screen close relatives of patients having supravalvular aortic stenosis and pulmonary branch stenosis by this non-invasive technic.