Nerve biopsy in T-cell lymphoma with neurolymphomatosis: where and when

Peripheral T-cell lymphomas are rare heterogeneous haematological malignancies that may also involve peripheral nerves in a very small subset of cases. We report a patient with a diagnostically challenging cutaneous T-cell lymphoma and multifocal mononeuropathies in whom a targeted nerve biopsy identified lymphomatous infiltration of nerves and expedited combination treatment with chemotherapy and an autologous stem cell transplant. She showed an excellent response with a complete metabolic response on positron emission tomography imaging and significant clinical improvement, maintained 5 years post-treatment.

Depression and anxiety symptoms remained elevated after 10 months of the COVID-19 pandemic in southern Brazil: findings from the PAMPA cohort

Objectives

This study aimed to examine the changes in depression and anxiety symptoms among Brazilian adults over 10 months of the COVID-19 pandemic.

Study design/Methods

The present study used data from wave 1 (June/July 2020) and wave 2 (December 2020/January 2021) of the Prospective Study About Mental and Physical Health (PAMPA) Cohort, a state-level, ambispective longitudinal study with adults from southern Brazil. The frequency of anxiety and depressive symptoms was assessed using the Hospital Anxiety and Depression Scale. Anxiety and depressive symptoms before social distancing were retrospectively assessed during wave 1.

Results

Most of the 674 participants were classified as non-symptomatic for depressive (85.0%) and anxiety symptoms (73.2%) before the COVID-19 pandemic. At wave 1, there were increases in symptoms of depression (7.6% [95% confidence interval [CI]: 7.2%, 8.1%]) and anxiety (9.1% [95% CI: 8.6%, 9.5%]). These decreased at wave 2 (depression: 6.9% [95% CI: 6.5%, 7.2%]; anxiety: 7.4% [95% CI: 7.1%, 7.8%]) although they were still elevated compared with pre-COVID (depression: 4.5% [95% CI: 4.2%, 4.8%]; anxiety: 5.8% [95% CI: 5.5%, 6.1%]). Adults living alone (b = 0.44 [95% CI: 0.07, 0.82]) had a faster trajectory in anxiety symptoms than their counterparts. Cohort members who were living alone (b = 0.24 [95% CI: 0.06, 0.42]) and with diagnosed chronic disease (0.32 [95% CI: 0.18, 0.46]) had a faster increase in depressive symptoms than their respective counterparts. Participants aged ≥60 years showed a slower trajectory of depressive (b = −0.46 [95% CI: −0.73, −0.18]) and anxiety (b = −0.61 [95% CI: −1.20, −0.02) symptoms.

Conclusions

During 10 months of COVID-19, anxiety and depression symptoms improved but were still higher than before COVID-19.

Prevalence and Severity of Ratoon Stunt in Commercial Brazilian Sugarcane Fields

Brazil has 9 million ha of sugarcane, 85% of which are located in the Center-South area of the country. Field trials and surveys around the globe have shown that ratoon stunt disease (RSD), caused by Leifsonia xyli subsp. xyli, can severely reduce tonnage yield. Previous small-scale studies in Brazil have demonstrated RSD infection in all varieties, with values varying from 25 to 68%. Nevertheless, the prevalence and severity of RSD in commercial fields had not previously been assessed. To address this issue, we surveyed 13,173 ha in 1,154 fields of the eight main sugarcane varieties of the Center-South area, taking 92,114 samples from 50 mills in five different states. Our data showed that 10% of fields were infected, and that 58% of mills had at least one RSD-infected field. The variety RB92579 had the highest proportion of infected fields (17%) and, on average, the prevalence and severity in these fields was high compared with other varieties. RB867515, the most cultivated in Brazil, showed infection in 6.2% of sampled fields (5.5% of sampled area) causing an estimated annual economic loss of over US$1 million. This was the first time the economic importance of RSD on Brazilian commercial sugarcane production was estimated. The Cerrado region had the highest prevalence of RSD: 16% of fields, 17% of the cultivated area, and 82% of mills. The use of diseased planting material was identified in 9% of plant cane fields, representing 10% of the cultivated area. Copyright © 2017 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Rosiglitazone modulates pigeon atherosclerotic lipid accumulation and gene expression in vitro

Atherosclerosis is a major contributor to the overall United States mortality rate, primarily in the form of heart attacks and stroke. Unlike the human disease, which is believed to be multifactorial, pigeon atherosclerosis is due to a single gene autosomal recessive trait. The White Carneau (WC-As) strain develops atherosclerotic plaques without the presence of known environmental risk factors such as diet and classic predictors such as blood pressure or blood cholesterol levels. With similar parameters, the Show Racer (SR-Ar) is resistant to plaque development. Thiazolidinediones, including rosiglitazone, activate the peroxisome proliferator-activated receptor gamma (PPARγ) raising cellular sensitivity to insulin. The effect of rosiglitazone was evaluated in aortic smooth muscle cells (SMC) from these 2 pigeon breeds. Primary SMC cultures were prepared from WC-As and SR-Ar squabs. Cell monolayers, which achieved confluence in 7 d, were treated with 0 or 4 µM rosiglitazone for 24 h. Cellular lipid accumulation was evaluated by oil red O staining. Control WC-As cells had significantly higher vacuole scores and lipid content than did the SR-Ar control cells. Rosiglitazone treatment decreased WC-As lipid vacuoles significantly compared with the control cells. On the other hand, lipid vacuoles in the treated and untreated SR-Ar cells did not differ significantly. The effect of rosiglitazone on WC-As SMC gene expression was compared with control SMC using representational difference analysis. Significant transcript increases were found for caveolin and RNA binding motif in the control cells compared with the rosiglitazone-treated cells as well as cytochrome p450 family 17 subfamily A polypeptide 1 (CYP171A) in the rosiglitazone-treated cells compared with the control cells. Although rosiglitazone was selected for these experiments because of its role as a PPARγ agonist, it appears that the drug also tempers c-myc expression, as genes related to this second transcription factor were differentially expressed. Both PPARγ and c-myc appear to affect WC-As SMC gene expression, which may relate to disease development, progression, or both.

Atherosclerosis-susceptible and atherosclerosis-resistant pigeon aortic cells express different genes in vivo

Spontaneous atherosclerosis in the White Carneau (WC-As) pigeon is inherited as a single gene disorder, and its progression closely mirrors the human disease. Representational difference analysis and microarray were used to identify genes that were differentially expressed between the susceptible WC-As and resistant Show Racer (SR-Ar) aortic tissue. The RNA extracted from 1-d-old squab aortas was used to make cDNA for each experiment. Fifty-six unique genes were found using representational difference analysis, with 25 exclusively expressed in the WC-As, 15 exclusive to the SR-Ar, and 16 nonexclusive genes having copy number variation between breeds. Caveolin and β-actin were expressed in the WC-As, whereas the proteasome maturation protein and the transcription complex CCR4-NOT were exclusive to the SR-Ar. Microarray analysis revealed 48 genes with differential expression. Vascular endothelial growth factor and p53 binding protein were among the 17 genes upregulated in the WC-As. Thirty-one genes were upregulated in the SR-Ar including the transforming growth factor-β signaling factor SMAD2 and heat shock protein 90. Genes representing several biochemical pathways were distinctly different between breeds. The most striking divergences were in cytoskeletal remodeling, proteasome activity, cellular respiration, and immune response. Actin cytoskeletal remodeling appears to be one of the first differences between susceptible and resistant breeds, lending support to the smooth muscle cell phenotypic reversion hypothesis of human atherogenesis.

Objectively measured patterns of physical activity in primary school children in Coventry: the influence of ethnicity

AIMS

The aetiology of increased metabolic risk in South Asians is incompletely understood, but may include modifiable factors such as physical activity. This study assessed patterns of physical activity in UK primary school children and examined the influence of ethnicity.

METHODS

We studied a community sample of children aged 8-9 years attending primary schools in Coventry, UK. One hundred and sixty-one children wore combined physical activity and heart rate monitors for 7 days. Levels of activity and energy expenditure were compared between White European (n = 96) and South Asian children (n = 65). Patterns of physical activity during the school week were also described.

RESULTS

Seventy-three per cent of White Europeans compared with only 35% of South Asians achieved international recommendations of 60 minutes of moderate to vigorous physical activity daily (P < 0.0000). South Asians were less active during the week (106 ± 28 vs. 120 ± 32 counts/min, respectively, P = 0.0054) and at weekends (92 ± 34 vs. 108 ± 54 counts/min, P = 0.0118) compared with White Europeans. There were differences in energy expenditure with lower physical activity levels in South Asians (daily average 1.68 ± 0.13 vs. 1.76 ± 0.17, P < 0.0001). Differences were attributable to less activity after school in South Asians (97 ± 29 vs. 120 ± 43 counts/min, P < 0.0000) as daytime activity was comparable between groups (120 ± 41 vs. 124 ± 39 counts/min, P > 0.05).

CONCLUSION

South Asian children in Coventry do significantly less physical activity than White Europeans, mainly attributable to differences in after-school activity. Ethnically tailored interventions should explore whether physical activity can be increased in South Asian children and, if so, whether this increased physical activity improves metabolic health.

Ethnicity and long-term heart rate variability in children

BACKGROUND

Low heart rate variability (HRV) is associated with increased cardiovascular disease risk. South Asians are at increased risk of cardiovascular disease.

METHODS

This cross-sectional, observational study compared long-term HRV between South Asian and White European (EU) children. 155 children (92 White EU, 63 South Asian) aged 8±1 years wore a combined heart rate and activity monitor for 7 days. From 24-h beat-to-beat heart rate recordings, long-term HRV was calculated as the SD of the average RR intervals in each 5 min period (SDANN). Physical activity, daily energy expenditure, percentage body fat and maximal oxygen consumption (VO2max) were calculated using published or commercial algorithms.

RESULTS

SDANN was significantly lower during the 24-h period in South Asian compared with White EU children (113±27 vs 130±28 ms, p<0.01, mean±SD) and during sleep (44±12 vs 54±16 ms, p<0.01, mean±SD). Ethnic differences in HRV were associated with lower levels of physical activity, daily energy expenditure, VO2max, and higher percentage body fat and resting heart rate, in South Asian children. Ethnic differences in HRV persisted despite statistical adjustment for these factors. SDANN was significantly lower in girls, but sex differences were no longer apparent when VO2max, physical activity and energy expenditure were statistically controlled for.

CONCLUSIONS

Our data confirm that South Asian children have lower HRV and reveal the novel information that the reduction is partially independent of physical activity and aerobic fitness.

Investigation of contact acoustic nonlinearities on metal and composite airframe structures via intensity based health monitoring

Nonlinear structural intensity (NSI) and nonlinear structural surface intensity (NSSI) based damage detection techniques were improved and extended to metal and composite airframe structures. In this study, the measurement of NSI maps at sub-harmonic frequencies was completed to provide enhanced understanding of the energy flow characteristics associated with the damage induced contact acoustic nonlinearity mechanism. Important results include NSI source localization visualization at ultra-subharmonic (nf/2) frequencies, and damage detection results utilizing structural surface intensity in the nonlinear domain. A detection metric relying on modulated wave spectroscopy was developed and implemented using the NSSI feature. The data fusion of the intensity formulation provided a distinct advantage, as both the single interrogation frequency NSSI and its modulated wave extension (NSSI-MW) exhibited considerably higher sensitivities to damage than using single-sensor (strain or acceleration) nonlinear detection metrics. The active intensity based techniques were also extended to composite materials, and results show both NSSI and NSSI-MW can be used to detect damage in the bond line of an integrally stiffened composite plate structure with high sensitivity. Initial damage detection measurements made on an OH-58 tailboom (Penn State Applied Research Laboratory, State College, PA) indicate the techniques can be transitioned to complex airframe structures achieving high detection sensitivities with minimal sensors and actuators.

Differentially expressed genes in aortic smooth muscle cells from atherosclerosis-susceptible and atherosclerosis-resistant pigeons

Susceptibility to spontaneous atherosclerosis in the White Carneau (WC-As) pigeon shows autosomal recessive inheritance. Aortic smooth muscle cells (SMC) cultured from susceptible WC-As and resistant Show Racer (SR-Ar) pigeons exhibit developmental and degenerative features corresponding to the respective SMC at atherosclerosis-prone sites in vivo. We used representational difference analysis to identify differentially expressed genes between WC-As and SR-Ar aortic SMC. Total RNA was extracted from cultured primary SMC of each breed, converted to double-stranded cDNA, followed by direct comparison in reciprocal representational difference analysis experiments. Difference products were cloned, sequenced, and identified by BLAST against the chicken genome. Six putative biochemical pathways were distinctly different between breeds with genes involved in energy metabolism and contractility exhibiting the most striking disparity. Genes associated with glycolysis and a synthetic SMC phenotype were expressed in WC-As cells. In contrast, SR-Ar cells expressed genes indicative of oxidative phosphorylation and a contractile SMC phenotype. In WC-As cells, the alternatives of insufficient ATP production limiting contractile function or the lack of functional contractile elements downregulating ATP synthesis cannot be distinguished due to the compressed in vitro versus in vivo developmental time frame. However, the genetic potential for effectively coupling energy production to muscle contraction present in the resistant SR-Ar was lacking in the susceptible WC-As.

Myasthenic syndrome caused by plectinopathy

BACKGROUND

Plectin crosslinks intermediate filaments to their targets in different tissues. Defects in plectin cause epidermolysis bullosa simplex (EBS), muscular dystrophy (MD), and sometimes pyloric atresia. Association of EBS with a myasthenic syndrome (MyS) was documented in a single patient in 1999.

OBJECTIVES

To analyze the clinical, structural, and genetic aspects of a second and fatal case of EBS associated with a MyS and search for the genetic basis of the disease in a previously reported patient with EBS-MD-MyS.

METHODS

Clinical observations; histochemical, immunocytochemical, and electron microscopy studies of skeletal muscle and neuromuscular junction; and mutation analysis.

RESULTS

An African American man had EBS since early infancy, and progressive muscle weakness, hyperCKemia, and myasthenic symptoms refractory to therapy since age 3 years. Eventually he became motionless and died at age 42 years. At age 15 years, he had a marked EMG decrement, and a reduced miniature endplate potential amplitude. The myopathy was associated with dislocated muscle fiber organelles, structurally abnormal nuclei, focal plasmalemmal defects, and focal calcium ingress into muscle fibers. The neuromuscular junctions showed destruction of the junctional folds, and remodeling. Mutation analysis demonstrated a known p.Arg2319X and a novel c.12043dupG mutation in PLEC1. The EBS-MD-MyS patient reported in 1999 also carried c.12043dupG and a novel p.Gln2057X mutation. The novel mutations were absent in 200 Caucasian and 100 African American subjects.

CONCLUSIONS

The MyS in plectinopathy is attributed to destruction of the junctional folds and the myopathy to defective anchoring of muscle fiber organelles and defects in sarcolemmal integrity.

Trichothiodystrophy with dysmyelination and central osteosclerosis

Trichothiodystrophy (TTD) is a rare group of autosomal recessive disorders of DNA repair unified by the presence of sulfur-deficient brittle hair. We report a 3-year-old boy with classic clinical features of TTD, including ichthyosis, alopecia, developmental delay, and tiger-tail banding of the hair shaft on polarizing microscopy. Brain MR imaging showed both diffuse dysmyelination and osteosclerosis, findings that, in combination, may be specific for TTD.

Ruptured maxillary retention cyst: cause of unilateral rhinorrhea after trauma

This study describes a case of a patient with traumatic rupture of a maxillary sinus retention cyst, which had an interesting clinical presentation of unilateral rhinorrhea, mimicking a CSF leak. The diagnosis was made fortuitously by comparison of a posttraumatic CT brain examination with a CT sinus study performed 1 day earlier.

Cardiac ECMO for biventricular hearts after paediatric open heart surgery

OBJECTIVE

To delineate predictors of hospital survival in a large series of children with biventricular physiology supported with extracorporeal membrane oxygenation (ECMO) after open heart surgery.

RESULTS

81 children were placed on ECMO after open heart surgery. 58% (47 of 81) were transferred directly from cardiopulmonary bypass to ECMO. Hospital survival was 49% (40 of 81) but there were seven late deaths among these survivors (18%). Factors that improved the odds of survival were initiation of ECMO in theatre (64% survival (30 of 47)) rather than the cardiac intensive care unit (29% survival (10 of 34)) and initiation of ECMO for reactive pulmonary hypertension. Important adverse factors for hospital survival were serious mechanical ECMO circuit problems, renal support, residual lesions, and duration of ECMO.

CONCLUSIONS

Hospital survival of children with biventricular physiology who require cardiac ECMO is similar to that found in series that include univentricular hearts, suggesting that successful cardiac ECMO is critically dependent on the identification of hearts with reversible ventricular dysfunction. In our experience of postoperative cardiac ECMO, the higher survival of patients cannulated in the operating room than in the cardiac intensive care unit is due to early effective support preventing prolonged hypoperfusion and the avoidance of a catastrophic cardiac arrest.

Susceptibility to spontaneous atherosclerosis in pigeons: an autosomal recessive trait

The inheritance pattern for susceptibility to spontaneous (noninduced) aortic atherosclerosis in pigeons was determined by crossbreeding and backcrossing experiments with atherosclerosis-susceptible White Carneau and atherosclerosis-resistant Show Racer breeds. Susceptibility, assessed by the presence of grossly visible lesions at the celiac bifurcation of the aorta at 3 years of age, demonstrated an inheritance pattern consistent with an autosomal recessive Mendelian trait. Cell culture studies indicated that susceptibility is a constitutive property of aortic cells as evidenced by vacuole formation and lipid content in smooth muscle cells from various tissues in susceptible pigeons.

Peripheral versus central muscarinic effects on blood pressure, cardiac contractility, heart rate, and body temperature in the rat monitored by radiotelemetry

Our laboratory has found that the organophosphate pesticide chlorpyrifos elicits an elevation in blood pressure that persists for approximately 24 hr after exposure. Since organophosphate pesticides inhibit acetylcholinesterase activity and cause cholinergic stimulation in the central nervous system and peripheral tissues, we suspect that the hypertensive response from chlorpyrifos is elicited by activation of pressor areas in the brain stem, specifically muscarinic receptors which are known to mediate hypertensive responses. Oxotremorine, a muscarinic agonist, should elicit a blood pressure response similar to organophosphate pesticides. This study used radiotelemetry to assess the effects of oxotremorine on blood pressure, heart rate, core temperature, QA interval (a measure of cardiac contractility), and motor activity in the male, Long-Evans rat. Subcutaneous co-administration of 0.2 mg/kg oxotremorine with 1.0 mg/kg methyl scopolamine (i.e., to block oxotremorine's peripheral effects) caused a marked elevation in blood pressure that developed concomitantly with a 2 degrees decrease in core temperature, 60 beats/min. increase in heart rate, increase in cardiac contractility but no change in motor activity. Overall, blood pressure increased by 19 mmHg from baseline and the response persisted for approximately 12 hr after injection. Methyl scopolamine alone increased heart rate but had no effect on blood pressure, core temperature, and motor activity. Oxotremorine injected without methyl scopolamine led to a relatively minor increase in blood pressure and hypothermia. Overall, central muscarinic stimulation with oxotremorine and methyl scopolamine leads to a vigorous hypertensive response that is associated with increased cardiac contractility, suggesting an increase in cardiac output. Combined central and peripheral cholinergic stimulation following oxotremorine without methyl scopolamine, as would also occur with exposure to chlorpyrifos and other organophosphate pesticides, did not elicit as much of a hypertensive response. This would suggest pathways other than those controlled directly with muscarinic receptors are operative in the development of chlorpyrifos-induced hypertension.

A role for cytokines in potentiation of malaria vaccines through immunological modulation of blood stage infection

Malaria is the world's major parasitic disease, for which effective control measures are urgently needed. One of the difficulties hindering successful vaccine design against Plasmodium is an incomplete knowledge of antigens eliciting protective immunity, the precise types of immune response for which to aim, and how these can be induced. A greater appreciation of the mechanisms of protective immunity, on the one hand, and of immunopathology, on the other, should provide critical clues to how manipulation of the immune system may best be achieved. We are studying the regulation of the balance between T helper 1 (Th1) and T helper 2 (Th2) CD4+ T lymphocytes in immunity to asexual blood stages of malaria responsible for the pathogenicity of the disease. Protective immunity to the experimental murine malarias Plasmodium chabaudi and Plasmodium yoelii involves both Th1 and Th2 cells, which provide protection by different mechanisms at different times of infection characterised by higher and lower parasite densities, respectively. This model therefore facilitates a clearer understanding of the Th1/Th2 equilibrium that appears central to immunoregulation of all host/pathogen relationships. It also permits a detailed dissection in vivo of the mechanisms of antimalarial immunity. Here, we discuss the present state of malaria vaccine development and our current research to understand the factors involved in the modulation of vaccine-potentiated immunity.

A dichotomous role for nitric oxide in protection against blood stage malaria infection

Nitric oxide (NO) is cytotoxic and cytostatic to blood stage malaria parasites in vitro, but the precise mechanism(s) by which it mediates an effect in vivo is not known. In particular, whether or not control of acute parasitemia depends on the presence of NO is unclear. We have shown previously that blocking NO synthesis at the time of its induction may cause an increase in peak primary parasitemia during infection of mice with Plasmodium chabaudi, suggesting that NO may be parasiticidal in vivo. However, as recent data indicate that NO suppresses Th1 cell proliferation in vitro by downregulating IL-2 production, we have investigated whether this immunoregulatory function of NO affects its capacity for anti-malarial activity. Treatment of P. chabaudi-infected mice with the iNOS inhibitor aminoguanidine hemisulfate (AG) starting just prior to the peak of primary parasitemia caused a significant elevation and extension of the acute infection and led to a partial but significant abrogation of the suppression of spleen cell proliferation to both mitogen and specific antigen observed when NO synthesis was not blocked. In the absence of NO, levels of IL-2, but not of IFN-gamma, TNF-alpha, or of any Th2-regulated cytokines examined, increased significantly. However, when AG treatment was brought forward to the early ascending phase of primary parasitemia, significantly increased levels of IFN-gamma and TNF-alpha, as well as of IL-2, were observed over those for infected control mice similarly treated with phosphate-buffered saline. Moreover, despite the absence of NO, parasitemias of AG-treated mice were not significantly elevated. The effect of AG therefore appeared to be dependent upon the timing of its administration in vivo. We propose that during malaria infections, there is a dynamic balance between the regulatory and anti-parasitic roles of NO. While the immunosuppressive function of NO leads to a downregulation in vivo of production of IL-2, and indirectly of IFN-gamma and TNF-alpha, this perceived weakening of the host cell-mediated immune response is in part masked by the protective anti-malarial effects of NO itself.

Modulation of experimental blood stage malaria through blockade of the B7/CD28 T-cell costimulatory pathway

Recent studies have implicated cytokines associated with CD4+ T lymphocytes of both T helper (Th)1 and Th2 subsets in resistance to experimental blood stage malaria. As the B7/CD28 costimulatory pathway has been shown to influence the differentiation of Th cell subsets, we investigated the contribution of the B7 molecules CD80 and CD86 to Th1/Th2 cytokine and immunoglobulin isotype profiles and to the development of a protective immune response to malaria in NIH mice infected with Plasmodium chabaudi. Effective blockade of CD86/CD28 interaction was demonstrated by elimination of interleukin (IL)-4 and up-regulation of interferon (IFN)-gamma responses by P. chabaudi-specific T cells and by reduction of P. chabaudi-specific immunoglobulin G1 (IgG1). The shift towards a Th1 cytokine pattern corresponded with efficient control of acute parasitaemia but an inability to resolve chronic infection. Moreover, combined CD80/CD86 blockade by using anti-CD80 and anti-CD86 monoclonal antibodies raised IFN-gamma production over that seen with CD86 blockade alone, with augmentation of this Th1-associated cytokine reducing levels of peak primary parasitaemia. These results demonstrate that IL-4 production by T cells in P. chabaudi-infected NIH mice is dependent upon CD86/CD28 interaction and that IL-4 and IFN-gamma contribute significantly, at different times of infection, to host resistance to blood stage malaria. In addition, combined CD80/CD86 blockade resulted in preferential expansion of IFN-gamma-producing T cells during P. chabaudi infection, suggesting that costimulatory pathways other than B7/CD28 may contribute to T-cell activation during continuous antigen stimulation. This study indicates a role for B7/CD28 costimulation in modulating the CD4+ T-cell response during malaria, and further suggests involvement of this pathway in other infectious and autoimmune diseases in which the Th cell immune response is also skewed.

Ethnic differences in testicular structure and spermatogenic potential may predispose testes of Asian men to a heightened sensitivity to steroidal contraceptives

Spermatogenesis in Asian men appears to be more susceptible to suppression by steroidal contraceptives administered in clinical trials than spermatogenesis in Caucasian men. The objective of this study was to determine whether ethnic differences exist in testicular structure and spermatogenic potential that might predispose Asians to a high sensitivity to steroidal contraceptives. Testes from 12 Chinese men were compared to those from 8 Hispanic men and 12 non-Hispanic Caucasian men of ages 29+/-3, 30+/-2, and 29+/-3 years, respectively. Testes were fixed by vascular perfusion with glutaraldehyde, further fixed in osmium, embedded in Epon, and evaluated by stereology using 0.5-microm sections stained with toluidine blue. Homogenates of fixed testes were evaluated for the number of Sertoli cells and the daily sperm production based on pachytene primary spermatocytes (PDSP) or spermatids with spherical nuclei (DSP). Paired parenchymal weight was less (P < 0.05) in Chinese men than in Hispanic or Caucasian men. The PDSP per gram of parenchyma was lower (P < 0.05) and the DSP per gram tended to be lower in Chinese men than in other groups. The histologic appearance, volume density, and length per man of seminiferous tubules were the same among the ethnic groups; however, the diameter of seminiferous tubules was less (P < 0.05) in Chinese than in Hispanic or Caucasian men. The PDSP per man and the DSP per man were lower (P < 0.05) in Chinese than in Hispanic or Caucasian men. The number of Sertoli cells per gram was higher (P < 0.05) in Chinese or Caucasian men than in Hispanic men, but the number of Sertoli cells per man was lower (P < 0.05) in Chinese men than in Hispanic or Caucasian men. Sertoli cell function, measured as the number of germ cells accommodated by a single Sertoli cell, was lower (P < 0.05) in Chinese men than in Caucasian men. The volume density of Leydig cell cytoplasm was greatest (P < 0.05) in Chinese men, but the number of Leydig cells was similar among the ethnic groups. Hence, smaller testes coupled with reduced Sertoli cell number and function and reduced daily sperm production could predispose Asian men to have a heightened negative response of testes to steroidal contraceptives, as compared to Caucasian men. Dampening (by exogenous androgens) of any physiological benefit to spermatogenesis that a high volume density of Leydig cell cytoplasm may bestow on the human testis (that Asian men may have evolved to require) would exacerbate ethnic differences in the spermatogenic response to hormonal contraceptives.

Structure-activity relationships of a series of 1-substituted-4-methylbenzimidazole neuropeptide Y-1 receptor antagonists

The characterization of a novel series of NPY-1 receptor antagonists derived from the 4-methylbenzimidazole 4 is described. Appropriate substitution on the piperidyl nitrogen of 4 led to systematic increases in Y-1 receptor affinity, to approximately 50-fold, and to the discovery of the importance of a second basic substituent.

Synthesis and 5 alpha-reductase inhibitory activity of 8-substituted benzo[f]quinolinones derived from palladium mediated coupling reactions

Benzoquinolinones have been shown to be potent, selective inhibitors of the Type I 5 alpha-reductase enzyme, which is responsible for the production of dihydrotestosterone from testosterone localized in the scalp. In an effort to identify compounds that demonstrate inhibition of both 5 alpha-reductase isozymes, we have employed 8-bromobenzoquinolinone as an advanced intermediate for participation in a variety of palladium mediated carbon-carbon bond forming reactions. By varying the 8-substituent it is possible to alter the selectivity profile of the series.

Intra-specific variation in the photosynthetic responses of cyanobiont lichens from contrasting habitats

The photosynthetic properties of cyanobiont lichens from contrasting habitats were measured to identify whether the increased assimilation rates which characterized Peltigera membranacea (Ach.) Nyl. from an exposed habitat were correlated with increased carbon-concentrating mechanism (CCM) activity. The results were contrasted with data obtained from two populations of Peltigera praetextata (Flörke ex Sommerf.) Zopf collected from dry and damp microhabitats within a shaded woodland and Peltigera leucophlebia (Nyl.) Gyelnik, which has been shown to lack a carbon-concentrating mechanism. The differences in assimilation rates between the cyanobiont lichens were not accounted for by differences in chlorophyll content. Peltigera membranacea from the exposed habitat which had the highest assimilation rates had the lowest Gamma; and K_0·5 values and accumulated the greatest C_i -pool indicating that increased C_i accumulation contributed towards the higher assimilation rates shown by these species. The convexity of the light response curve for the cyanobiont lichens decreased with increasing assimilation rates. This might have indicated a diversion of electron transport to energize the carbon-concentrating mechanism. The apparent quantum efficiency of CO₂ assimilation (ΦCO₂ ) was correlated with the genus of lichen photobiont. All cyanobiont lichens had comparable values for ΦCO₂ which were greater than that of the tripartite Peltigera leucophlebia. Light compensation points reflected the exposure of the habitats with higher compensation points characterizing the cyanobiont population from the exposed crag and the tri-partite population from the open grassland. Carbon isotope discrimination values for organic matter and measured instantaneously were the same for all cyanobiont lichens and were comparable with values recorded for species with a carbon-concentrating mechanism. Carbon isotope measurements for P. leucophlebia were typical of those recorded for species without a carbon-concentrating mechanism. Variation in source isotope signature and refixation of respiratory CO₂ were considered to be significant factors in determining organic matter and instantaneous carbon-isotope discrimination. These factors might have masked any subtle variation in carbon-isotope discrimination which resulted from variable CCM activity. The functional significance of increased carbon-concentrating mechanism activity in cyanobiont lichens occupying exposed habitats is discussed.

In vivo proton magnetic resonance spectroscopy in polymyositis and dermatomyositis: a preliminary study

The aim of the study is to determine whether biochemical abnormalities, such as lipid, creatine and choline metabolites, are observed in the more distal muscles of polymyositis (PM) and dermatomyositis (DM) patients. 12 patients suffering from chronic active PM/DM and 9 controls underwent a combined proton magnetic resonance (MR) imaging and proton MR spectroscopy study of the calf muscle. From a combination of T1-weighted MR images and corresponding fat suppressed images, fat infiltration into the muscle of both PM and DM patients was consistently observed. Muscular atrophy with a variable distribution was also noted in all patients. The biochemical profile of the localised proton MR spectra of soleus muscle showed reduction of both 'choline' to lipid and 'creatine' to lipid ratios in chronic PM and DM patients when compared with controls.

Components for the implementation of free-space optical crossbars

We describe an optical system developed to form the basis of a 64 × 64 free-space optical matrix-matrix crossbar switch. The design and performance of each of the main optical components is discussed: lenses, diffractive optical elements, and polarizing beamsplitters, together with the optomechanical hardware design. For these components, throughput levels of -6.9 dB have been achieved, which is compatible with full system operation at 10(-12) bit error rates at ≥270 Mbits s(-1).

Standardising joint assessment in rheumatoid arthritis

Evaluating joint involvement in rheumatoid arthritis in a key clinical assessment. We investigated the extent of variation in measurement of joint swelling and tenderness and evaluated the impact of training to standardise methods. Eight observers (medical and nursing staff) examined eight rheumatoid patients for joint swelling and tenderness before and after training in clinical methods. The EULAR handbook for joint evaluation was used for training and assessments were based on the 28 joint count. There was extensive variability in both numbers of swollen and tender joints. Coefficients of variation for articular indices recorded by the 8 observers in individual patients were often high (up to a maximum of 204%), indicating considerable differences between observers. Training had an impact on the assessment of the numbers of swollen joints which increased by a mean of 32% (P < 0.05) and the number of tender joints which increased by 41% (p < 0.01). Training had only a limited impact on the variation among observers in determining the number of swollen and number of tender joints. After training, the mean coefficients of variation were still 59% for swollen joints and 65% for tender joints. These results highlight the extent of variation in clinical assessment of rheumatoid arthritis and show the advantages of training. It leads to increased sensitivity of measurement. Standardisation appears essential for clinical studies.

The clinical need for an acute rheumatology referral service

Should rheumatologists provide an acute referral service for general practitioners (GPs) and other clinical units? Is it cost effective? We prospectively studied acute referrals to one unit over 10 months, recording their source, diagnosis, management and outcome. Current rheumatology patients and cases only needing telephone advice were excluded. There were 253 referrals: 82 from GPs, nine from Accident and Emergency, and 162 from other hospital units. Their diagnoses comprised connective tissue diseases (22), back pain (46), inflammatory arthritis (59), osteoarthritis (22), paediatric cases (11), soft tissue problems (41) and 52 other disorders. Thirty-two needed active treatment within 24 h (classified as emergencies); examples included cerebral lupus, vasculitic pulmonary haemorrhage, retroperitoneal lymphoma with sacral plexus compression, temporal arteritis with reduced visual acuity and acute monoarthritis. All needed immediate therapy; only one died. Most (176 cases) were less urgent and needed advice in 48 h. Examples included osteoporotic vertebral collapse and acute rheumatoid disease. Forty-five could have been seen routinely; examples included lateral epicondylitis and adhesive capsulitis. The service required 1 day per week of medical staff time at an average cost of 45 pounds per case. We concluded that an acute rheumatology service is needed; it can be provided within the working day and is cost effective.

Diagnosis and management of the dry mouth: Part 1

Dry mouth is a relatively common problem, often neglected by patients and dentists alike. This article reviews the symptoms, causes and treatment of xerostomia and provides guidelines for recognizing the condition at an early stage.

The efficacy of filters used in respiratory function apparatus

The ability of two low resistance barrier filters (Collins DC-1 and Pall Pf 305) to remove bacteria from expired air was assessed. A specially designed coupling device was used to hold each filter or a disposable plain cardboard mouthpiece a fixed distance (4.5 cm) from a blood agar plate. Volunteers performed maximal forced vital capacity manoeuvres through the assembled apparatus and bacteria impinged on to the agar plate were enumerated. Both filters allowed the transmission of approximately one-third of expired colony forming units. The efficacy of these filters for reducing the likelihood of cross-infection during spirometry is not supported by this study.

Comparison of twenty three nebulizer/compressor combinations for domiciliary use

We have assessed the physical and dynamic characteristics of 23 home jet nebulizer/compressor combinations currently available in the UK and Europe. The combinations were evaluated in terms of pressure-flow characteristics, aerosol mass distribution, volume output, electrical costs, and sound level. In addition, we determined the effect of nebulizer fill volume on aerosol mass distribution and volume output. One nebulizer was used with six different compressors, and four compressors were tested with three different nebulizers. The pressure-flow relationships showed a wide variation between models, as did flow-rate at the nebulizer (range 3.0-8.0 L.min-1). The mean +/- SD volume nebulized after 10 min using an initial fill volume of 2.5 and 5.0 mL was 46 +/- 9 and 34 +/- 12%, respectively. The mass median aerodynamic diameter (MMAD) over a 5 min nebulization ranged 2.6 to 10.2 microns. Nine of the nebulizations produced an MMAD of less than 5 microns at both fill volumes. Changing nebulizer/compressor combinations affected flow rate, MMAD and volume output. Sound levels varied between models. Running costs were low, with all using less than 74 kilowatt hours of energy per year. We conclude that there is a wide variation in performance of nebulizer/compressor combinations for use with nebulized bronchodilators. Correct matching of the nebulizer/compressor is seen to be important to ensure optimum performance.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of cocaine in end-stage renal disease in some hypertensive African Americans

During a period of 1 year we observed 12 African American patients who had smoked or sniffed cocaine for several years and presented to inner city hospitals with accelerated hypertension and renal insufficiency. Ten required maintenance dialysis; 1 recovered partially after a brief period of dialysis, and 1 had moderate renal insufficiency. In the absence of striking proteinuria, cardiomegaly or renal shrinkage, the probable diagnosis in most of the patients was primary accelerated hypertension. The clinical history suggested that the habitual use of cocaine had worsened the hypertension, made it more difficult to control or triggered an accelerated phase resulting in renal shutdown. At a time when billions of dollars are being spent on the treatment of end-stage renal disease, the harmful role of cocaine in susceptible individuals requires due attention.

Intra-articular injections of 750 kD hyaluronan in the treatment of osteoarthritis: a randomised single centre double-blind placebo-controlled trial of 91 patients demonstrating lack of efficacy

OBJECTIVE

To determine the safety and efficacy of intra-articular injections of hyaluronan in the treatment of osteoarthritis of the knee.

METHODS

A randomised double-blind placebo-controlled trial was carried out on 91 patients with radiologically confirmed osteoarthritis of the knee who were recruited from the outpatient clinics.

RESULTS

It was found that weekly intraarticular injections of 20 mg of hyaluronan of M(r) = 750,000 (Hyalgan) in 2 ml of buffered saline performed no better than the inert vehicle alone over a five week period. The principal side effects of a transient increase in pain and swelling in the affected knee was observed in 47% of the treatment group compared with 22% of the placebo group. A few patients with radiologically mild disease treated with Hyalgan appeared to experience medium to long-term symptomatic improvement over matched placebo controls as judged by a delayed return to previous NSAID therapy or analgesia other than paracetamol. Patient numbers in the survival groups, however, were too small to be meaningful.

CONCLUSION

It is concluded that intraarticular administration of this preparation of 750 kD hyaluronan offers no significant benefit over placebo during a five week treatment period, but incurs a significantly higher morbidity, and therefore has no place in the routine treatment of osteoarthritis.

How do inhaled bronchodilators work?

1. Beta-agonists affect bronchodilation of the airways by their action on the bronchial smooth muscles. 2. Anticholinergic drugs affect bronchodilation of the airways by blocking the effect of acetylcholine and its bronchoconstrictor action. 3. Receptors are protein molecules found in cell membranes; they can selectively bind to messenger molecules and transduce a chemical signal into a response in a target cell.

An investigation of the abnormal metabolic status of synovial fluid from patients with rheumatoid arthritis by high field proton nuclear magnetic resonance spectroscopy

The 1H Hahn spin-echo NMR profiles of rheumatoid synovial fluids have been investigated and compared with those of matched serum samples. In addition to markedly elevated lactate and diminished glucose concentrations, inflammatory synovial fluids contained (i) substantially lower levels of NMR-detectable chylomicron-and very-low-density-lipoprotein-associated triacylglycerols which appear to have a shortened mean chain-length, and (ii) high concentrations of ketone bodies (predominantly 3-D-hydroxybutyrate), relative to those of corresponding paired serum samples. These observations confirm the abnormal metabolic status of the inflamed rheumatoid joint and provide evidence for an increased utilisation of lipids for fuel therein.

Serum immunoreactive erythropoietin in patients with idiopathic aplastic and Fanconi's anaemias

In patients with idiopathic aplastic anaemia (n = 34) and Fanconi's anaemia (n = 8), sampled once or on several occasions, serum erythropoietin (Epo) increased with increasing severity of anaemia with apparently similar rates of increase in each group. However, after adjustment for Hb, log Epo values for the Fanconi's anaemics tended to be greater than those for the idiopathic aplastic anaemics (P < 0.01). Erythropoietin concentrations in serum samples from patients with Fanconi's and idiopathic aplastic anaemias tended to be greater than in samples from patients with anaemias from protein energy malnutrition, myelodysplasia and iron deficiency. The results suggest that there is no deficiency of erythropoietin in Fanconi's and idiopathic aplastic anaemias and that if exogenous erythropoietin is of any benefit it would need to be administered in doses large enough to induce a significant increase in log Epo. Results of the study illustrate the need to take account of the assumptions which underlie interpretation of the statistical analysis. Use of erythropoietin values in place of log Epo gives misleading conclusions demonstrable as invalid as the conditions for normality of distribution of the data and homogeneity of variances were not satisfied.