Synoptic assessment of coastal total alkalinity through community science

Comprehensive sampling of the carbonate system in estuaries and coastal waters can be difficult and expensive because of the complex and heterogeneous nature of near-shore environments. We show that sample collection by community science programs is a viable strategy for expanding estuarine carbonate system monitoring and prioritizing regions for more targeted assessment. 'Shell Day' was a single-day regional water monitoring event coordinating coastal carbonate chemistry observations by 59 community science programs and seven research institutions in the northeastern United States, in which 410 total alkalinity (TA) samples from 86 stations were collected. Field replicates collected at both low and high tides had a mean standard deviation between replicates of 3.6 ± 0.3 μmol kg^-1 (σ _mean ± SE, n = 145) or 0.20 ± 0.02%. This level of precision demonstrates that with adequate protocols for sample collection, handling, storage, and analysis, community science programs are able to collect TA samples leading to high-quality analyses and data. Despite correlations between salinity, temperature, and TA observed at multiple spatial scales, empirical predictions of TA had relatively high root mean square error >48 μmol kg^-1. Additionally, ten stations displayed tidal variability in TA that was not likely driven by low TA freshwater inputs. As such, TA cannot be predicted accurately from salinity using a single relationship across the northeastern US region, though predictions may be viable at more localized scales where consistent freshwater and seawater endmembers can be defined. There was a high degree of geographic heterogeneity in both mean and tidal variability in TA, and this single-day snapshot sampling identified three patterns driving variation in TA, with certain locations exhibiting increased risk of acidification. The success of Shell Day implies that similar community science based events could be conducted in other regions to not only expand understanding of the coastal carbonate system, but also provide a way to inventory monitoring assets, build partnerships with stakeholders, and expand education and outreach to a broader constituency.

Synoptic assessment of coastal total alkalinity through community science

Comprehensive sampling of the carbonate system in estuaries and coastal waters can be difficult and expensive because of the complex and heterogeneous nature of near-shore environments. We show that sample collection by community science programs is a viable strategy for expanding estuarine carbonate system monitoring and prioritizing regions for more targeted assessment. 'Shell Day' was a single-day regional water monitoring event coordinating coastal carbonate chemistry observations by 59 community science programs and seven research institutions in the northeastern United States, in which 410 total alkalinity (TA) samples from 86 stations were collected. Field replicates collected at both low and high tides had a mean standard deviation between replicates of 3.6 ± 0.3 μmol kg-1 (σ mean ± SE, n = 145) or 0.20 ± 0.02%. This level of precision demonstrates that with adequate protocols for sample collection, handling, storage, and analysis, community science programs are able to collect TA samples leading to high-quality analyses and data. Despite correlations between salinity, temperature, and TA observed at multiple spatial scales, empirical predictions of TA had relatively high root mean square error >48 μmol kg-1. Additionally, ten stations displayed tidal variability in TA that was not likely driven by low TA freshwater inputs. As such, TA cannot be predicted accurately from salinity using a single relationship across the northeastern US region, though predictions may be viable at more localized scales where consistent freshwater and seawater endmembers can be defined. There was a high degree of geographic heterogeneity in both mean and tidal variability in TA, and this single-day snapshot sampling identified three patterns driving variation in TA, with certain locations exhibiting increased risk of acidification. The success of Shell Day implies that similar community science based events could be conducted in other regions to not only expand understanding of the coastal carbonate system, but also provide a way to inventory monitoring assets, build partnerships with stakeholders, and expand education and outreach to a broader constituency.

Microscopic polyarteritis presenting with skin necrosis in a patient with sickle-cell disease

A 20-year-old Caribbean woman with sickle cell anaemia was admitted with a 4-day history of fever and a painful swollen right ankle. She rapidly developed skin necrosis. The differential diagnosis is discussed. This case illustrates the difficulty in identifying the cause of cutaneous necrosis in an acutely ill patient. In our patient, histopathology implicated a vasculitic process, which was subsequently identified as a manifestation of microscopic polyarteritis.

PNP with Waldenstrom's macroglobulinaemia

We describe a 65-year-old Caucasian man with Waldenstrom's macroglobulinaemia who developed paraneoplastic pemphigus (PNP) 3 years after his haematological diagnosis. This is a very rare malignancy that is associated with PNP. The evolution of PNP in this patient appears to exhibit the postulated immunological phenomenon of epitope spreading.

The joint vulval clinic: a review of the first three years

This aim of this study was to undertake a retrospective analysis of the notes of all new patients who attended the joint vulval clinic between 1994 and 1997. One hundred and forty-five patients were seen, and data analysed for 133 (92%). The study identified the range of diagnoses seen; treatment modalities undertaken; and enabled comparisons to be made between our findings and those of other workers.

Epstein-Barr virus-related post-transplant lymphoproliferative disorder with t(9;14)(p11-12;q32)

The immunoglobulin heavy chain gene locus on 14q32 is known to be involved in translocations that are associated with B-lymphoproliferative disorders, typically Burkitt lymphoma and B-cell acute lymphoblastic leukemia. Several cytogenetic abnormalities have been described in post-transplant lymphoproliferatve disease (PTLD), some of which include this locus. To our knowledge, we report the first case of translocation t(9;14)(p11-12;q32) in a PTLD that developed after orthoptic liver transplantation.

Functional and compositional studies of arteries stored in University of Wisconsin solution compared with Krebs-Bülbring buffer

Endothelium-dependent and -independent vasorelaxation in ring segments of rabbit thoracic aorta is reduced and noradrenaline-induced vasoconstriction unaltered after prolonged storage in University of Wisconsin solution (UW) compared to arteries stored in extracellular-type solutions such as Krebs-Bülbring buffer (KBB). The aims of the present study were to determine whether angiotensin-II-induced vasoconstriction, alterations in myosin light chains, protein synthetic capacity, and subcellular structures are altered after 8 days of UW storage at 4 degrees C. The present study showed reduced contractility to angiotensin II, following 8 days of cold storage in UW, that was not reversed in the presence of a nitric oxide synthase inhibitor, N(G)-nitro-l-arginine methyl ester (100 microM). Measurements of contractile protein ratios in the same tissues after cold storage in UW or KBB did not show any significant alterations in smooth muscle myosin light chains or protein synthetic capacity (reflected by total RNA). It is concluded that reductions in vasoconstriction in UW-stored tissue are unlikely to be due to increased release of nitric oxide nor reduced availability of myosin light chains for phosphorylation and vasoconstriction.

Characterisation of molecular alterations in microdissected archival gliomas

Classification of gliomas according to their molecular characteristics may be important in future histopathological diagnosis. However, gliomas frequently display heterogeneity at the histological, biological and molecular level. In this study of archival diagnostic gliomas, precision microdissection was used to enrich samples in the most malignant cells or to investigate intratumoural histological heterogeneity. Analysis of tumour samples microdissected from the most aggressive regions, representative of the histopathological diagnosis, revealed PTEN mutations in 4/14 anaplastic astrocytomas, 4/13 glioblastomas and 1 gliosarcoma, but not in 19 low-grade gliomas. Using a novel PCR procedure and direct sequence analysis of the entire coding sequence, TP53 mutations were detected in 1/3 pilocytic astrocytomas, 3/13 astrocytomas, 4/14 anaplastic astrocytomas, 5/13 glioblastomas and 1 gliosarcoma. All but one of the tumours with TP53 mutation showed p53 immunopositivity, but 5 low-grade and 10 high-grade gliomas had p53 protein nuclear accumulation in the absence of detectable mutation. p53 status was unrelated to p21 expression. Neither PTEN nor TP53 mutations influenced the proliferative index or microvessel density of high-grade astrocytomas. Unusual findings include: TP53 mutation in a juvenile pilocytic astrocytoma; TP53 and PTEN mutations in a de novo glioblastoma, a gliosarcoma with identical mutations in gliomatous and sarcomatous components, and an infratentorial anaplastic astrocytoma with an earlier supratentorial grade II astrocytoma bearing the same TP53 mutation but not the PTEN mutation or loss of heterozygosity (LOH) of 10q23. Similarly, the transition to high-grade histology was associated with acquisition of PTEN mutations and 10q23.3 LOH in two de novo high-grade tumours with regions of low-grade histology.

Comparative effects of acute ethanol dosage on liver and muscle protein metabolism

Experiments were performed to address some outstanding issues and investigate possible mechanisms relating to the acute comparative effects of ethanol on liver and skeletal muscle protein metabolism. Ethanol (EtOH)-treated rats were injected (i.p.) with a bolus of EtOH (75 mmol/kg body weight) and sacrificed at 20 min, 1-, 2.5-, 6-, and 24-hr time points. Control rats were injected with saline (Con-Sal; 0.15 mmol/L NaCl). All 24-hr ethanol-treated animals were compared with saline-injected rats subjected to controlled feeding (i.e. pair-fed controls for 24 hr EtOH). At 24 hr, there was no measurable alcohol in the plasma, whereas high levels were seen from 20 min to 6 hr (up to 448 mg/dL). Plasma levels of albumin were reduced at initial time points, and activities of aspartate aminotransferase increased, but there was no histological evidence of overt tissue damage either in muscle or liver. Hepatic protein and RNA contents and indices of tissue (C(s) and k(s)) and whole-body (V(s)) protein synthesis were significantly increased in ethanol-dosed rats relative to saline-injected pair-fed controls at 24 hr. In the liver, four of the seven cytoplasmic proteases investigated (alanyl-, arginyl-, and pyroglutamyl-aminopeptidases and proline-endopeptidase) showed significant increases in activity at 24 hr relative to pair-fed controls; four of the six lysosomal proteases showed significant decreases in activity (dipeptidyl-aminopeptidase II and cathepsins B, L, and H). In skeletal muscle, k(s) fell progressively between 1 and 24 hr (-25 to -69%; P < 0.001), but no significant changes in skeletal muscle protease activities were seen at 24 hr. At 24 hr after ethanol dosage in vivo, there were no significant increases in protein carbonyl content in liver or skeletal muscle compared to pair-fed controls (muscle levels actually decreased slightly). However, using either rat or human tissue, both liver and muscle carbonyl increased in vitro in response to superoxide and hydroxyl radicals: muscle was more susceptible to carbonyl formation than liver and both tissues were more sensitive to hydroxyl compared to superoxide radicals. These results show divergent effects of acute ethanol treatment on liver and skeletal muscle protein metabolism, which may not be linked to in vivo free radical-mediated protein damage (as indicated by carbonyl formation), at least in the short term.

Global water resources: vulnerability from climate change and population growth

The future adequacy of freshwater resources is difficult to assess, owing to a complex and rapidly changing geography of water supply and use. Numerical experiments combining climate model outputs, water budgets, and socioeconomic information along digitized river networks demonstrate that (i) a large proportion of the world's population is currently experiencing water stress and (ii) rising water demands greatly outweigh greenhouse warming in defining the state of global water systems to 2025. Consideration of direct human impacts on global water supply remains a poorly articulated but potentially important facet of the larger global change question.

Novel polymerase chain reaction approach for full-coding p53 mutation detection in microdissected archival tumors

Evidence suggests that up to 25% of p53 mutations are outside of exons 5-8 and that insertions, deletions, and polymorphic sites in the p53 gene may play a significant role in the process of carcinogenesis. A novel polymerase chain reaction (PCR) approach for the analysis of the entire p53 coding and splice site regions from microdissected, formalin-fixed, paraffin-embedded tumor tissues has been developed which allows multiple genetic analyses to be performed from one primary amplification reaction. The method was initially evaluated using well-characterized cell lines. In addition to confirming the published p53 mutations for HT29, Molt 4, A431, and HN5, a 16 base pair (bp) duplication within intron 3 was detected in both the A431 and HT29 cell lines. Analysis of archival samples of ovarian cancer identified the same 16-bp duplication and coding region variations. In all samples, using GenBank submission U94788 as a reference, a C-insertion was detected at nucleotide positions 11818 and 11874 within intron 2. At nucleotide position 14168, within intron 7, a T-to-G base change was found. This novel PCR approach has the potential to reduce the amount of clinical material required by up to 95%, thus facilitating retrospective studies on archival tumor collections. Furthermore, a wider analysis of the p53 gene, including splice sites and intronic regions, may yield additional information regarding cancer predisposition, response to therapy, and progression.

Effect of perfusate albumin on organ viability and vascular responses in the in vitro dual-perfused rat liver

Inclusion of albumin in the perfusate has been previously shown to be detrimental to liver function, but its effect on hepatic vascular reactivity remains unknown. The aim of this study was to determine the effects of albumin on hepatic arterial vascular reactivity and liver viability in the isolated dual-perfused rat liver. A total of 12 rat livers were perfused with Krebs-Bülbring buffer without (Group 1) and with (Group 2) addition of 1% bovine serum albumin (BSA) through the hepatic artery and portal vein for up to 5 h. Hepatic arterial responses to acetylcholine and sodium nitroprusside were studied at 30-min intervals. Liver viability was assessed by bile volume production, release of aspartate serine aminotransferase (AST) and lactic acid dehydrogenase (LDH), and histological examination. Hepatic arterial responses to acetylcholine were significantly attenuated in Group 2. No significant differences in sodium nitroprusside responses were noted. However, bile volume production in Group 2 was significantly decreased compared to Group 1. Effluent AST and LDH release increased significantly in Group 1 but not in Group 2. Histological results showed that sinusoidal endothelial cells and hepatocytes were well preserved without significant deterioration in either group, although there was a marked decrease in vasodilatation to acetylcholine in Group 2. This data suggested that the presence of albumin in the perfusate did not improve retention of smooth muscle reactivity and reduced endothelium-dependent vasodilatation and bile volume production during perfusion. However, improved liver parenchymal cell function was observed.

Paradoxical cholinergic and purinergic vascular reactivity of rabbit thoracic aorta cold-stored in University of Wisconsin solution

Endothelial dysfunction has been reported in donor blood vessels destined for organ transplantation following cold-storage preservation with University of Wisconsin solution (UW). This was investigated in the present work. Segments of rabbit thoracic aorta were mounted on isometric fine-wire myographs at 37 degrees C and gassed with 95% O2/5% CO2. Concentration-dependent vasodilatations to acetylcholine and adenosine-5'-triphosphate (ATP) were obtained in freshly-harvested rabbit aortic rings, with and without the endothelium, and after 8 days of cold-storage, at 4 degrees C, in either UW, Krebs-Bülbring buffer (KBB) or saline. The action of the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) (100 microM) was evaluated upon the concentration-response curves to determine whether nitric oxide (NO) exerted any modulatory actions. Endothelium-dependent, NO-mediated responses to acetylcholine were unaltered after eight days of storage in UW, reduced after storage in KBB and absent after removal of the vascular endothelium, saline storage or after testing in the presence of L-NAME, suggesting improved NO-mediated endothelial function with the use of UW. Structural preservation was also confirmed using scanning electron microscopy. In contrast, endothelium-dependent responses to ATP were unchanged after eight days of storage in KBB but were reduced after storage in UW and saline, suggesting purinergic (ATP) endothelial dysfunction after storage in UW. L-NAME markedly reduced vasodilatation to ATP in freshly harvested rings and after eight days of storage in KBB. This reduction was statistically significant (P < 0.05, Student's two tailed, unpaired t-test) at -log (M) ATP concentrations of 5.5, 5.0, 4.5, 4.0 and 3.5. NO-dependent vasodilatation to ATP was not attenuated by L-NAME in UW-stored rings. Eight days' UW-storage of rabbit thoracic aortic rings appeared to have differential and paradoxical effects upon NO-dependent vasodilatation to acetylcholine and ATP. Morphological observations using electron microscopy suggested that UW preserved the vascular endothelium and this was verified by retained vascular reactivity of endothelium-dependent vasodilatations to acetylcholine. UW-storage however, significantly reduced endothelium-dependent relaxation to ATP thereby suggesting that P2Y-purinoceptors, which are located on the vascular endothelium, may be more susceptible to biodegradation than cholinergic receptors and may be responsible for endothelial dysfunction following transplantation.

Mutation in the PTEN/MMAC1 gene in archival low grade and high grade gliomas

The PTEN gene, located on 10q23.3, has recently been described as a candidate tumour suppressor gene that may be important in the development of advanced cancers, including gliomas. We have investigated mutation in the PTEN gene by direct sequence analysis of PCR products amplified from samples microdissected from 19 low grade (WHO Grade I and II) and 27 high grade (WHO grade III and IV) archival, formalin-fixed, paraffin-embedded gliomas. Eleven genetic variants in ten tumours have been identified. Eight of these are DNA sequence changes that could affect the encoded protein and were present in 0/2 pilocytic astrocytomas, 0/2 oligoastrocytomas, 0/1 oligodendroglioma, 0/14 astrocytomas, 3/13 (23%) anaplastic astrocytomas and 5/14 (36%) glioblastomas. PTEN mutations were found exclusively in high grade gliomas; this finding was statistically significant. Only two of the PTEN genetic variants have been reported in other studies; two of the genetic changes are in codons in which mutations have not been found previously. The results of this study indicate that mutation in the PTEN gene is present only in histologically more aggressive gliomas, may be associated with the transition from low histological grade to anaplasia, but is absent from the majority of high grade gliomas.

Cutaneous Rosai-Dorfman disease

We report a patient with purely cutaneous Rosai-Dorfman disease (RDD) who presented with a solitary, asymptomatic plaque on the back of her left thigh, with characteristic, large histiocytoid cells exhibiting emperipolesis histologically. Cutaneous lesions occur in 27% of patients with lymph node involvement in RDD however purely cutaneous disease has only been reported on 18 previous occasions. The aetiology is unknown, although it is though to be a reactive disorder rather than neoplastic, possibly an immunological response to an infectious agent.

Cold-storage of rabbit thoracic aorta in University of Wisconsin solution reduces endothelium-independent vasodilation

Optimum preservation conditions for storage of donor livers and blood vessels are essential for successful transplantation. The blood vessels are used as vascular conduits to facilitate anastomosis of the liver to the recipient's systemic vasculature. Failure of some transplants has been ascribed to thrombosis of these vascular conduits possibly because of alterations in vascular reactivity owing to inadequate storage techniques. To restrict data variability previously associated with studies using a heterogeneous sample of vessels from man, this study investigated changes in vascular reactivity in segments of rabbit thoracic aorta from male, age-matched, New Zealand White rabbits stored at 4 degrees C in either University of Wisconsin solution (UW; Du Pont Pharmaceuticals, UK) or Krebs-Bülbring buffer (KB). Percent vasodilation to acetylcholine remained significantly greater in UW than in KB at -log (M) concentrations of 7.0 (UW = 47.05 +/- 4.26 compared with KB = 13.20 +/- 7.20%; P < 0.001), 6.5 (UW = 66.82 +/- 4.83 compared with KB = 26.60 +/- 9.48%; P < 0.01), and 6.0 (UW = 83.68 +/- 5.26 compared with KB = 31.20 +/- 9.83%; P < 0.001). This was not significantly different to relaxation in unstored arteries and suggested improved endothelial function and structure, confirmed by electron microscopy. Percent vasodilation to sodium nitroprusside was significantly lower in UW than in unstored (D0) arteries at -log (M) concentrations of 7.5 (D0 = 28.27 +/- 4.02 compared with UW = 15.21 +/- 1.82%; P < 0.01), 7.3 (D0 = 52.58 +/- 5.05 compared with UW = 29.23 +/- 1.94%; P < 0.01), 7.0 (D0 = 69.70 +/- 4.85 compared with UW = 49.72 +/- 2.49%; P < 0.05), and 6.4 (D0 = 93.16 +/- 2.93 compared with UW = 71.29 +/- 5.20%; P < 0.05). Percent vasodilation was also lower in UW- compared with KB-stored arteries at -log (M) sodium nitroprusside concentrations of 7.0 (UW = 49.72 +/- 2.49 compared with KB = 64.11 +/- 5.03%; P < 0.05) and 6.4 (UW = 71.29 +/- 5.20 compared with KB = 96.91 +/- 5.96; P < 0.05). Electron microscopy confirmed that this was not a result of degradation of smooth muscle structure. The nitric oxide synthase inhibitor L-NG-nitro-L-arginine methyl ester (100 microM) did not significantly modulate sodium nitroprusside-induced vasodilation in unstored arteries, when endothelial function was maximum, or in UW-stored arteries, suggesting that the reduced responses in UW-stored arteries were not because of increased synthesis of nitric oxide. This reduced relaxation to sodium nitroprusside was therefore nitric oxide-independent and not a result of competition between sodium nitroprusside and endothelial 'nitric oxide donation' for cGMP. In summary, cold-storage preservation with UW reduced endothelium-independent vascular relaxation by mechanisms other than competition with NO; this requires further evaluation.

Studies on the time-course of ethanol's acute effects on skeletal muscle protein synthesis: comparison with acute changes in proteolytic activity

A study of the effects of ethanol on skeletal muscle protein synthesis and protease activities was carried out in young male Wistar rats (150 g) for up to 24 hr after a single intraperitoneal dose of 75 mmol of ethanol/kg of body weight. At 20 min, the mean blood ethanol levels were 448 mg/dl. This level dropped steadily to zero through the following 24 hr. Compared with pair-fed controls, significant reductions in total protein, RNA, and DNA contents were seen only after 24 hr in all skeletal muscles studied: changes were more marked in the muscles containing large proportions of type II fibers. In plantaris muscle, the fractional rate of protein synthesis (ks, %/day) did not fall 20 min after dosage but was reduced after 1 hr by 23% (p < 0.001), and by 63% after 24 hr, compared with control saline-injected rats (p < 0.001). This effect was independent of dietary intake because, compared with the pair-fed group, the 24-hr ethanol-treated rats still showed a 52% decrease in fractional rates of protein synthesis (p < 0.001). Smaller reductions in ks were seen in soleus muscles in response to ethanol at 24 hr (-39%, p < 0.001). The activities of a variety of lysosomal and nonlysosomal proteases in plantaris muscle of 24-hr treated rats were not significantly affected by ethanol. Only alanyl- and tripeptidyl-aminopeptidase activities were reduced significantly (26%, p < 0.05 and 39%, p < 0.01, respectively). These results suggest that the muscle compositional changes seen over acute periods of ethanol toxicity are predominantly associated with impaired synthesis of protein and that the contribution of cellular proteolytic systems may be minimal. The effects of ethanol on skeletal muscle protein metabolism are greater in muscles containing a predominance of type II fibers than in those containing mainly type I fibers. Ethanol's effects on muscle may be influenced by hormonal changes after 24 hr, because protein synthesis is still compromised and free plasma T3 and corticosterone are altered at this time-point.

Systemic bone changes accompanying early rheumatoid arthritis in patients treated with nonsteroidal antiinflammatory drugs alone

Seventeen patients suffering from early rheumatoid disease (mean duration, 3.5 years) and treated with nonsteroidal antiinflammatory drugs alone had evidence of systemic bone changes. Transiliac bone biopsies, compared with age and gender-matched controls, demonstrated reduced bone volume and increased eroded surface. In addition, the metacarpal indices were reduced in the rheumatoid patients and correlated with the iliac crest bone volume. These changes, found distal from sites of synovitis, suggest that in this group of rheumatoid patients there were systemic changes of bone metabolism. No biochemical abnormalities of calcium homeostasis were found. Collectively, present observations may be a reflection of the rheumatoid disease process itself.

Vasopressin receptor-mediated endocytosis in cells transfected with V1-type vasopressin receptors

We examined the process of receptor-mediated endocytosis in A-9 lung fibroblast and chinese hamster ovary (CHO) cells transfected with the recently cloned vasopressin V1a receptor (51). We used a fluorescent labeled vasopressin analog (rhodamine-mercaptopropionic acid lysine vasopressin) and radiolabeled vasopressin to examine this process in the two transfected cell lines. Both A-9 and CHO cells internalize vasopressin in a manner consistent with receptor-mediated endocytosis. A-9 cells internalize vasopressin more rapidly than CHO cells. The process is inhibited by vasopressin and by specific vasopressin V1 receptor antagonists but not by specific V2 receptor antagonists. Hypertonic sucrose inhibits endocytosis in both cell types suggesting a role of clathrin coated pits in the endocytosis of receptor in these cells. These cells are excellent models in which to examine the effect of receptor mutations on vasopressin receptor-mediated endocytosis.

Bilateral external chalazia presenting as granulomas of the lower eyelids

A 2-year-old oriental boy with bilateral symmetrical external chalazia is described. The diagnosis of this very unusual clinical picture became apparent only after histological examination and consultation with an eyelid specialist.

Nuclear morphometry of primary B cell thyroid lymphoma

Thyroid lymphoma is usually distinguished from anaplastic thyroid carcinoma and from Hashimoto's thyroiditis by morphological and immunohistochemical assessment of tissue sections. Our objective was to assess the value of nuclear morphometry in the differential diagnosis of these conditions. Nuclear area measurements were performed on 10 cases of thyroid lymphoma using an IBAS 2000 Image Analyser and compared with similar measurements performed on 10 cases of Hashimoto's thyroiditis and 2 of anaplastic thyroid carcinoma. It was found that karyometry demonstrated differences between all three conditions, the cases of thyroiditis being distinguishable from lymphoma on the basis of mean nuclear area alone. Mean nuclear area for lymphomas was greater than for Hashimoto's thyroiditis and lower than for anaplastic carcinomas. The mean nuclear area also reflected the grade of lymphoma, with the exception of one case which had a large reactive T cell population. It is concluded that nuclear morphometry provides valuable information in the diagnosis and assessment of thyroid lymphomas.

A vasopressin analog that binds but does not activate V1 or V2 vasopressin receptors is not internalized into cells that express V1 or V2 receptors

To assess whether receptor binding is sufficient to initiate vasopressin receptor endocytosis in cells expressing the vasopressin V1 or V2 receptors, we synthesized a novel fluorescent-labeled vasopressin analog, [1-(beta-mercapto-beta, beta-cyclopentamethylene propionic acid), 2-(O-ethyl)-D-tyrosine, 4-valine, 8-lysine-N6-carboxytetramethylrhodamine] vasopressin (R-CLVP), that binds to vasopressin receptors but does not activate intracellular events such as the mobilization of intracellular calcium or the activation of adenylate cyclase. We compared the manner in which this analog was endocytosed in cells expressing V1 (A-10, rat smooth muscle cells) or V2 (LLC-PK1, porcine kidney cells) receptors with that of a full agonist, [1-(beta-mercaptopropionic acid), 8-lysine-N6-carboxytetramethylrhodamine] vasopressin (R-MLVP) [Lutz et al. (1990) J. Biol. Chem. 265, 4657-4663; Lutz et al. (1990) Proc. Natl. Acad. Sci. U.S.A. 87,6507-6511]. We showed that R-CLVP bound to both types of receptors with good affinity. It failed to increase cyclic AMP concentrations in LLC-PK1 cells and did not increase the mobilization of intracellular calcium in A-10 cells. It bound to the surface of both these cell types in a diffuse manner and it did not undergo receptor endocytosis in either cell type. In contrast, R-MLVP, an agonist that bound to both receptor subtypes and elicited changes in intracellular cyclic AMP and calcium, bound to the surface of these cells in a diffuse manner at early times after exposure, and rapidly underwent endocytosis. We conclude that binding of vasopressin to its receptors alone is insufficient to cause receptor endocytosis, and other events distal to the receptor are required to initiate endocytosis. R-CLVP should be a useful analog in determining the factors responsible for initiating receptor endocytosis.

Focal nodular hyperplasia of the liver: a link with sickle cell disease?

Focal nodular hyperplasia is a benign liver tumour that is rare in children. We report the second case of a child with sickle cell disease presenting with symptomatic focal nodular hyperplasia. The possible pathogenesis of focal nodular hyperplasia and the association with sickle cell disease are discussed.

Production and specificity of monoclonal antibodies against calmodulin from Dictyostelium discoideum

Monoclonal antibodies were raised against calmodulin purified from Dictyostelium discoideum. To increase its antigenicity, the calmodulin was conjugated to keyhole limpet hemocyanin; mice were immunized with the conjugate. Hybridomas producing antibodies against calmodulin were identified by screening culture supernatants with calmodulin coupled to bovine serum albumin. The specificity of antibodies from hybridoma culture supernatants was tested by Western blot of Dictyostelium cell lysates. For the purpose, methods were developed that permitted sensitive detection of calmodulin bound to membranes. The key elements of the blotting protocol were used of PVDF membrane, transfer conducted in phosphate buffer, and glutaraldehyde fixation after transfer. These methods permitted detection of as little as 0.1 ng of calmodulin spotted directly onto the membrane, or 10 ng transferred from an SDS polyacrylamide gel. Ten calmodulin-specific antibodies were identified; most of these reacted preferentially with the calcium-containing form of Dictyostelium calmodulin. Several of the monoclonal antibodies cross-reacted with calmodulin from bovine brain.

Internalization of vasopressin analogs in kidney and smooth muscle cells: evidence for receptor-mediated endocytosis in cells with V2 or V1 receptors

To determine whether receptor-mediated endocytosis occurs in vasopressin-responsive cells, we developed a model system using synthetic fluorescent-labeled vasopressin analogs and A10 (smooth muscle) and LLC-PK1 (kidney epithelial) cells in culture; these cell lines express V1 and V2 vasopressin cell surface receptor types, respectively. We used epifluorescence microscopy to examine the binding, internalization, and intracellular destination of [1-(2-mercapto)propionic acid,8-lysine-N6-carboxytetramethylrhodamine] vasopressin (R-MLVP) and [1-(2-mercapto)propionic acid,8-lysine-N6-carboxyfluorescein]vasopressin (F-MLVP) in these cells. The rhodamine-labeled fluorescent vasopressin analog, R-MLVP, initially bound in a diffuse manner at the cell surface of both A10 and LLC-PK1 cells and could be displaced by excess unlabeled [8-arginine]vasopressin. After incubation at 37 degrees C, bound ligand rapidly aggregated into small clusters or patches, which were internalized in a manner consistent with receptor-mediated endocytosis. Subsequent processing of internalized ligand-receptor complexes appeared to differ between A10 and LLC-PK1 cells. In the case of LLC-PK1 cells, ligand was delivered to a tightly focused lysosome compartment in the perinuclear region of the cell, and receptor molecules were replenished at the cell surface. The lysosomal location of ligand was supported by the quenching of fluorescence in the internalized vesicles when F-MLVP was used as a fluorescent tracer. In the case of A10 cells, ligand became localized to a vesicular compartment and reappearance of receptor at the cell surface was limited. Our data are consistent with the occurrence of receptor-mediated endocytosis of vasopressin in cells with V1 and V2 receptors.

Epidemic Norwegian scabies in a geriatric unit

Norwegian scabies is highly contagious and presents with a psoriasiform dermatosis. It afflicts particularly the elderly and patients with immunosuppression. Two weeks after the admission of an index case of Norwegian scabies to a geriatric ward, 13 and 25 patients and 6 of 18 ward nurses developed scabies. Despite comprehensive treatment, the ward epidemic recurred 6 weeks later probably as a result of inadequate treatment of the index case. This diagnosis should be considered when patients from high-risk groups present with an undiagnosed rash.

Interleukin 3 alone does not support the proliferation of bone marrow cells from A/J mice: a novel system for studying the synergistic activities of IL-3

The number of colonies produced by bone marrow cells in response to interleukin 3 (IL-3) in soft agar cultures varies according to the strain of the donor mice. A/J, AKR, A.TH and A.TL bone marrow cells are particularly hyporesponsive, producing only occasional colonies in the presence of IL-3. Bone marrow cells from all strains of mice, including A/J, produce distinctively large colonies in response to the combination of IL-3 and macrophage colony stimulating factor (M-CSF). In cultures of A/J bone marrow cells, the synergy between IL-3 and M-CSF is further reflected in an increase in both the number and the variety of colonies produced. The increase in colony numbers may be due to the priming of a population of A/J colony-forming-cells (CFCs) by IL-3, enabling them to respond to M-CSF. In support of this notion, IL-3 enhanced the level of c-fms (M-CSF receptor) messenger RNA in cultures of A/J bone marrow cells. It is also possible that a subpopulation of CFCs requires both IL-3 and M-CSF as co-mitogens. The A/J strain provides a novel system for studying the mechanisms involved in the interaction between IL-3 and M-CSF in haemopoiesis.

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Ruptured abdominal aortic aneurysm in Marfan's syndrome

A rare case of ruptured abdominal aortic aneurysm in Marfan's syndrome is described. The patient was treated successfully with a straight aortic tube graft. Histology of the aneurysm wall showed changes typical of cystic medial necrosis.

Acropustulosis of infancy

Acropustulosis of infancy is a syndrome characterized by recurrent pruritic acral vesicopustules. It occurs primarily in black male infants and hitherto has been described mainly in the North American literature. We describe four cases seen in London. This entity, therefore, should be recognized in the U.K., particularly in the differential diagnosis of infantile scabies.