Futuristic Alzheimer's therapy: acoustic-stimulated piezoelectric nanospheres for amyloid reduction

The degeneration of neurons due to the accumulation of misfolded amyloid aggregates in the central nervous system (CNS) is a fundamental neuropathology of Alzheimer's disease (AD). It is believed that dislodging/clearing these amyloid aggregates from the neuronal tissues could lead to a potential cure for AD. In the present work, we explored biocompatible polydopamine-coated piezoelectric polyvinylidene fluoride (DPVDF) nanospheres as acoustic stimulus-triggered anti-fibrillating and anti-amyloid agents. The nanospheres were tested against two model amyloidogenic peptides, including the reductionist model-based amyloidogenic dipeptide, diphenylalanine, and the amyloid polypeptide, amyloid beta (Aβ42). Our results revealed that DPVDF nanospheres could effectively disassemble the model peptide-derived amyloid fibrils under suitable acoustic stimulation. In vitro studies also showed that the stimulus activated DPVDF nanospheres could efficiently alleviate the neurotoxicity of FF fibrils as exemplified in neuroblastoma, SHSY5Y, cells. Studies carried out in animal models further validated that the nanospheres could dislodge amyloid aggregates in vivo and also help the animals regain their cognitive behavior. Thus, these acoustic stimuli-activated nanospheres could serve as a novel class of disease-modifying nanomaterials for non-invasive electro-chemotherapy of Alzheimer's disease.

First Evidence of Axial Shape Asymmetry and Configuration Coexistence in ^{74}Zn: Suggestion for a Northern Extension of the N=40 Island of Inversion

The excited states of N=44 ^{74}Zn were investigated via γ-ray spectroscopy following ^{74}Cu β decay. By exploiting γ-γ angular correlation analysis, the 2_{2}^{+}, 3_{1}^{+}, 0_{2}^{+}, and 2_{3}^{+} states in ^{74}Zn were firmly established. The γ-ray branching and E2/M1 mixing ratios for transitions deexciting the 2_{2}^{+}, 3_{1}^{+}, and 2_{3}^{+} states were measured, allowing for the extraction of relative B(E2) values. In particular, the 2_{3}^{+}→0_{2}^{+} and 2_{3}^{+}→4_{1}^{+} transitions were observed for the first time. The results show excellent agreement with new microscopic large-scale shell-model calculations, and are discussed in terms of underlying shapes, as well as the role of neutron excitations across the N=40 gap. Enhanced axial shape asymmetry (triaxiality) is suggested to characterize ^{74}Zn in its ground state. Furthermore, an excited K=0 band with a significantly larger softness in its shape is identified. A shore of the N=40 "island of inversion" appears to manifest above Z=26, previously thought as its northern limit in the chart of the nuclides.

Lead-Free Perovskite Cs3Bi2I9-Derived Electroactive PVDF Composite-Based Piezoelectric Nanogenerators for Physiological Signal Monitoring and Piezo-Phototronic-Aided Strain Modulated Photodetectors

In recent years, lead-free perovskite materials are exponentially emerging in photovoltaic and optoelectronic applications due to their low toxicity and superior optical properties. On the other hand, the demand for flexible, wearable, and lightweight optoelectronic devices is significantly growing in sensor and actuator technologies. In this scenario, lead-free perovskite-based flexible piezoelectric polymer composites have sparked considerable attention in this field due to their excellent piezo-, pyro-, ferroelectric, and photovoltaic properties. Thus, in this work, a long-term stable lead-free Cs₃Bi₂I₉-PVDF composite is introduced. The in situ growth of the Cs₃Bi₂I₉ perovskite induces 92% yield of the electroactive phase in the PVDF matrix. The possible mechanism behind the electroactive β-phase transformation is presented via interfacial interactions of PVDF moieties with the Cs₃Bi₂I₉ (CBI) perovskite, which also give rise to long-term environmental stability. Next, a piezoelectric nanogenerator (PNG) has been fabricated with the Cs₃Bi₂I₉-PVDF composite for mechanical energy harvesting, biophysiological motion monitoring, and voice recognitions that have potential utility in the health-care sector. Furthermore, a photodetector is developed to realize the piezo-phototronic effect. It exhibits a fast photoswitching behavior with rise and decay times of 141 and 278 ms, respectively. Thus, it is confirmed that the flexible Cs₃Bi₂I₉-PVDF composite has shown tremendous potential to be used as an optical signal-modulated piezo-responsive wearable sensor.

Surface Potential Tuned Single Active Material Comprised Triboelectric Nanogenerator for a High Performance Voice Recognition Sensor

To fabricate a high-performance and ultrasensitive triboelectric nanogenerator (TENG), choice of a combination of different materials of triboelectric series is one of the prime challenging tasks. An effective way to fabricate a TENG with a single material (abbreviated as S-TENG) is proposed, comprising electrospun nylon nanofibers. The surface potential of the nanofibers are tuned by changing the voltage polarity in the electrospinning setup, employed between the needle and collector. The difference in surface potential leads to a different work function that is the key to design S-TENG with a single material only. Further, S-TENG is demonstrated as an ultrahigh sensitive acoustic sensor with mechanoacoustic sensitivity of ≈27 500 mV Pa^-1 . Due to high sensitivity in the low-to-middle decibel (60-70 dB) sounds, S-TENG is highly capable in recognizing different voice signals depending on the condition of the vocal cord. This effective voice recognition ability indicates that it has high potential to open an alternative pathway for medical professionals to detect several diseases such as neurological voice disorder, muscle tension dysphonia, vocal cord paralysis, and speech delay/disorder related to laryngeal complications.

Can echocardiographic parameters predict mortality in COVID-19?

Introduction

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), otherwise known as the coronavirus (COVID-19) pandemic presents one of the greatest medical challenges of our generation. Whilst commonly causing a viral pneumonitis, myocardial damage has also been suggested by elevated serum troponin values greater than the 99th centile in up to 30% of individuals who require hospitalisation and correlates with increased mortality.

Purpose

We aim to identify whether transthoracic echocardiography (TTE) parameters can elucidate the phenomenon of abnormal troponin levels. Furthermore, we seek to characterise the most frequent demographic, biochemical, echocardiographic features and co-morbidities associated with adverse outcomes in this cohort.

Methods

A retrospective analysis was conducted utilising electronic patient records of consecutive hospitalised patients with a positive COVID-19 swab between 1st March and 31st October 2020 who underwent a TTE at our institution. Pertinent variables were collected including: the clinical indication, demographics including cardiovascular (CV) risk factors, peak troponin values and fundamental echocardiographic parameters.

Results

During this 8-month period, a total of 90 patients underwent a TTE. The mean age of the cohort was 63 years of age and 56% were male. More than half (56.6%) were admitted to the intensive care unit (ICU). A salient 41.1% (n=37) of our cohort succumbed to this devastating virus. Notably, 38.9% (n=35) were of black and minority ethnic origin (BAME). A striking 64.9% (n=24) of patients who died had hypertension. The mean troponin levels were 168.7 ng/L and 176.6 ng/L (0–34 ng/L) in the survivors and non-survivors group respectively. With regards to TTE, the left ventricular parameters were similar between both groups with a mean left ventricular ejection fraction (LVEF) of 60.6% in the non-survivors. Conversely, both right ventricular (RV) dysfunction (37.8%) and raised pulmonary artery systolic pressures (PASP) (51.4%) were markedly more frequent in the patients who perished due to COVID-19 infection.

Conclusion

Remarkably, in this extremely ill group of patients who died, 91.9% of patients had a preserved LVEF. There were no overt differences between troponin levels in the survivors and non-survivors. However, hypertension, RV dysfunction and raised PASP were distinctly more prominent in the non-survivors. Thus, providing insight that a normally functioning left ventricle does not preclude to poor outcomes. Overall, this single-centre retrospective study demonstrates that the echocardiographic phenotype associated with mortality is consistent with a severe respiratory illness rather than direct myocardial injury from COVID-19. A multi-modality imaging approach may facilitate the identification of adverse tissue characterisation changes associated with this novel virus as well as guiding further risk stratification and patient management on a case-by-case basis.

Funding Acknowledgement

Type of funding sources: None.

Tunable, conductive, self-healing, adhesive and injectable hydrogels for bioelectronics and tissue regeneration applications

Conductive hydrogels are attracting considerable interest in view of their potential in a wide range of applications that include healthcare and electronics. Such hydrogels are generally incorporated with conductive materials/polymers. Herein, we present a series of conductive hydrogels (Ch-CMC-PDA), prepared with no additional conductive material. The hydrogels were synthesized using a combination of chitosan, cellulose (CMC) and dopamine (DA). The conductivity (0.01-3.4 × 10^-3 S cm^-1) in these gels is attributed to ionic conductivity. Very few conductive hydrogels are endowed with additional properties like injectability, adhesiveness and self-healing, which would help to widen their scope for applications. While the dynamic Schiff base coupling in our hydrogels facilitated self-healing and injectable properties, polydopamine imparted tissue adhesiveness. The porosity, rheological, mechanical and conductive properties of the hydrogels are regulated by the CMC-dialdehyde-polydopamine (CMC-D-PDA) content. The hydrogel was evaluated in various bioelectronics applications like ECG monitoring and triboelectric nanogenerators (TENG). The ability of the hydrogel to support cell growth and serve as a template for tissue regeneration was confirmed using in vitro and in vivo studies. In summary, the integration of such remarkable features in the ionic-conductive hydrogel would enable its usage in bioelectronics and biomedical applications.

How common is aortic dilatation?

Funding Acknowledgements

Type of funding sources: None.

Introduction

Aortic dilatation is most commonly associated with hypertension, bicuspid aortic valve and connective tissue diseases such as Marfan’s. It is a precursor to life threatening complications such as rupture or dissection of the aorta. The current ESC Guidelines recommend surgical intervention once the aortic diameter is >50 mm in patients with Marfan syndrome (Ic) and >55 mm in patients with a bicuspid or normal aortic valve morphology (IIb). There is currently a lack of literature on the prevalence of aortic dilatation in the general or even hospital population although there is historical data suggesting the incidence of thoracic aortic aneurysm to be 5.9 cases per 100,000.

Purpose

The aim is to investigate the prevalence of aortic dilatation by echocardiography in our hospital population which may help lay the foundation for population studies and identify prognostic factors which may determine the time of surgical intervention.

Methods

We carried out a retrospective survey using the digital echocardiogram archive and the electronic patient record system at our hospital. This survey covered the period between 1st October 2016 and 1st November 2018. For randomisation  purposes, all transthoracic echocardiograms (TTE) performed on every Thursday during this period were included. All patients with an echocardiographic report of aortic root or ascending aorta dilatation were enrolled. Other information including echocardiographic dimensions along with demographics and past medical history was collected.

Results

During this 24-month period, we analysed a total of 3019 TTEs. 209 patients (6.9%) were reported to have aortic dilatation. 137 (66%) were male and the median age was 67 years. The mean height and weight were 169cm and 80kg, respectively.  A bicuspid aortic valve was confirmed in 10 (4.8%) patients. 132 (63%) patients had a history of hypertension. On echocardiogram, 75 (36%) patients had septal hypertrophy and 26 (12.4%) had a dilated left ventricle.  

Conclusion

Our findings are unique and for the first time, to our knowledge, we report the echocardiographic prevalence of aortic dilatation in the hospital population (6.9%). It is a staggering 40-fold increase when compared to the the prevalence of aortic aneurysm, the most likely end point of aortic dilatation. Based on our figures, there would be at least 400 patients with a dilated aorta in a year in our hospital alone. The prevalence of bicuspid aortic valve in our cohort (4.8%) was nearly three times higher than the general population where it is quoted as 1-2%. Our study also emphasised the established link between hypertension and aortic dilatation with an increased frequency in our cohort (63%) compared to the global prevalence (31%). Given the devastating sequelae of aortic dilatation and its increased prevalence in our patient population, it will be very important to keep these patients under routine surveillance and particularly those with hypertension.

Erratum: Direct Observation of Proton Emission in ^{11}Be [Phys. Rev. Lett. 123, 082501 (2019)]

This corrects the article DOI: 10.1103/PhysRevLett.123.082501.

Direct Observation of Proton Emission in ^{11}Be

The elusive β^{-}p^{+} decay was observed in ^{11}Be by directly measuring the emitted protons and their energy distribution for the first time with the prototype Active Target Time Projection Chamber in an experiment performed at ISAC-TRIUMF. The measured β^{-}p^{+} branching ratio is orders of magnitude larger than any previous theoretical model predicted. This can be explained by the presence of a narrow resonance in ^{11}B above the proton separation energy.

Second generation cephalosporin antibiotic prophylaxis and Clostridium difficile infection in hip and knee arthroplasty

Introduction The use of broad spectrum cephalosporin antibiotics has been discouraged by the Department of Health in England because of the link to increased Clostridium difficile infection rates. The aim of this study was to evaluate whether a local protocol that included the use of second generation cephalosporin (cefuroxime) antibiotics as a prophylactic agent was associated with increased risk of C difficile in elective hip and knee arthroplasty patients. Methods A retrospective intention-to-treat study was conducted. An infection control database of all cases of C difficile infection both in hospital and in the community was reviewed and cross-referenced against surgical records. A positive correlation was identified when a C difficile positive sample was documented within eight weeks of arthroplasty surgery. Results Only 1 case (0.02%) of C difficile positive diarrhoea was identified that correlated to the 8-week postoperative period following 4,488 arthroplasty procedures. Conclusions The use of cephalosporin antibiotic prophylaxis in the elective hip and knee arthroplasty setting does not appear to be associated with increased C difficile infection rates, achieving surgical site infection rates that are comparable with the national average.

Effect of curcumin in mice model of vincristine-induced neuropathy

CONTEXT

Curcumin exhibits a wide spectrum of biological activities which include neuroprotective, antinociceptive, anti-inflammatory, and antioxidant activity.

OBJECTIVE

The present study evaluates the effect of curcumin in vincristine-induced neuropathy in a mice model.

MATERIALS AND METHODS

Vincristine sulfate (0.1 mg/kg, i.p. for 10 consecutive days) was administered to mice to induce neuropathy. Pain behavior was assessed at different days, i.e., 0, 7, 10, and 14 d. Sciatic nerve total calcium, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH), nitric oxide (NO), and lipid peroxidation (LPO) were also estimated after the 14th day of study. Pregabalin (10 mg/kg, p.o.) and curcumin (15, 30, and 60 mg/kg, p.o.) were administered for 14 consecutive days.

RESULTS

Curcumin at 60 mg/kg significantly attenuated the vincristine-induced neuropathic pain manifestations in terms of thermal hyperalgesia (p < 0.001) and allodynia (p < 0.001); mechanical hyperalgesia (p < 0.001); functional loss (p < 0.001); and in the delayed phase of formalin test (p < 0.001). Curcumin at 30 and 60 mg/kg exhibited significant changes (p < 0.001) in antioxidant levels and in total calcium levels in vincristine-injected mice.

CONCLUSION

Curcumin at 30 and 60 mg/kg dose levels significantly attenuated vincristine-induced neuropathy which may be due to its multiple actions including antinociceptive, calcium inhibitory, and antioxidant effect.

Emergence of Lineage IV Peste des Petits Ruminants Virus in Ethiopia: Complete Genome Sequence of an Ethiopian Isolate 2010

Isolates of peste des petits ruminants virus (PPRV) can be segregated genetically into four lineages. For decades, lineages I-III have been reported across Africa whilst lineage IV has predominantly circulated across Asia. However, the lineage distribution is currently changing in Africa. Importantly, full genome sequence data for African field isolates have been lacking. Here, we announce the first complete genome sequence of a field isolate of peste des petits ruminants virus (PPRV) from East Africa. This isolate was derived from the intestine of a goat suffering from severe clinical disease during the 2010 outbreak in Ethiopia. The full genome sequence of this isolate, PPRV Ethiopia/2010, clusters genetically with other lineage IV isolates of PPRV, sharing high levels of sequence identity across the genome. Further, we have carried out a phylogenetic analysis of all of the available African partial N gene and F gene PPRV sequences to investigate the epidemiology of PPRV with a focus on the emergence of different lineages of PPRV in Africa.

Tablet in the bronchus--an unusual cause for persistent cough in a 64 year old gentleman

Foreign body aspiration in adults without any background risk factors is uncommon. We report a 64 year gentleman evaluated for persistent cough incidentally detected to have a foreign body (FB) in the left main bronchus (LMB), which after removal by rigid bronchoscopy turned out to be a tablet. This demonstrates the possible risk of silent aspiration of solid foreign bodies and in our case presenting as a persistent cough after months of aspiration. Bronchoscopic evaluation should be carried out in the differential diagnosis of persistent or recurrent pulmonary symptoms.

Basiliximab with delayed introduction of calcineurin inhibitors as a renal-sparing protocol following liver transplantation in children with renal impairment

Renal impairment is frequently compromised in patients with end-stage liver disease and is associated with increased long-term mortality post-LT. In contrast to CNI, basiliximab is an immunosuppressive agent with minimal nephrotoxic potential. This study reviews the experience of a single pediatric liver transplant center's renal-sparing approach with the use of basiliximab and MMF to compensate for delayed entry of CNI in children with renal impairment at the time of organ availability. There were no differences in renal function between pediatric patients with and without pre-LT renal impairment within the first year (cGFR: 135 mL/min/1.73 m2 vs. 144 mL/min/1.73 m2 ; p = 0.56) or at 5-8 yr following LT, (129 mL/min/1.73 m2 vs. 130 mL/min/1.73 m2 ; p = 0.97). In addition, there was no difference in ACR rates (50% vs. 43%, p = 0.62) between patients in the basiliximab group and those patients receiving standard CNI and steroid strategies. The utilization of a renal-sparing approach with basiliximab alongside delayed entry and lower early target trough levels of CNI in children with renal impairment at the time of LT is safe and maintains excellent long-term kidney function.

Canagliflozin for the treatment of type 2 diabetes

Canagliflozin, an oral inhibitor of sodium/glucose cotransporter 2 (SGLT2) in the kidneys, leads to glucosuria and provides a unique mechanism to lower blood glucose levels in diabetes. It corrects a novel pathophysiological defect, has an insulin-independent action, reduces HbA1c by 0.5 to 1.1%, promotes weight loss, has a low incidence of hypoglycemia, complements the action of other antidiabetic agents, can be used at any stage of diabetes and appears to be safe in patients with compromised renal function. Due to side effects such as urinary tract and genital infections and decrease in blood pressure, proper patient selection for drug initiation and close monitoring will be important. Results of ongoing cardiovascular safety trials are important to determine the risk-benefit ratio. Canagliflozin is the first oral SGLT2 inhibitor approved in the U.S. market and it represents a promising approach for the treatment of diabetes in this era of increasing obesity.

Cerebral infarction in patient with minimal change nephrotic syndrome

We report a case of 68-year-old Caucasian man who presented with cerebral infarcts secondary to arterial thrombosis associated with nephrotic syndrome. His initial presentation included edema of legs, left hemiparesis, and right-sided cerebellar signs. Investigations with computed tomography and magnetic resonance imaging of brain showed multiple cerebral infarcts in middle cerebral and posterior cerebral artery territory. Blood and urine investigations also showed impaired renal function, hypercholesterolemia, hypoalbuminaemia, and nephrotic range proteinuria. Renal biopsy showed minimal change disease. Cerebral infarcts were treated with antiplatelet agents and nephrotic syndrome was treated with high dose steroids. Patient responded well to the treatment and is all well till date.

Traumatic rupture of the tibialis anterior tendon associated with chronic tibialis posterior dysfunction

Isolated rupture of the tibialis anterior and tibialis posterior tendon is uncommon with approximately 25 cases reported in the English literature. Rupture of the tibialis anterior in the presence of chronic tibialis posterior dysfunction has not been reported to date. We present a patient with a closed traumatic rupture of the tibialis anterior tendon which occurred on a background of a pre-existing tibialis posterior dysfunction which was being treated non-operatively and discuss the successful operative management that was performed to reconstruct both tendons.

Behavioral and electroantennographic responses of the tea mosquito, Helopeltis theivora, to female sex pheromones

Responses of the tea mosquito, Helopeltis theivora (Waterhouse) (Hemiptera: Miridae), a major pest of tea, to female sex pheromone compounds were measured using wind tunnel and electroantennogram (EAG) bioassays. In the wind tunnel, male tea mosquitoes were found to be most attracted to a dichloromethane extract of the female thorax. Gas chromatography-mass spectrometry (GC-MS) analysis of female thoracic extracts and dynamic head space samples of virgin females showed the presence of five compounds: (Z)-3 hexenyl acetate, (Z)-3 hexenyl butanoate, (E)-2 hexenyl pentanoate, 2,4 dimethyl pentanal, and (E)-2-hexenol. Male tea mosquitoes were attracted to blends of (Z)-3 hexenyl acetate and (E)-2-hexenol in the wind tunnel with a 1:5 ratio eliciting the greatest response. EAG recordings of male antenna confirmed the ability of this blend to evoke antennal responses in male insects. Similarly active EAG responses were recorded toward female thoracic extract and a blend of (Z)-3 hexenyl acetate and (E)-2-hexenol. Behavioral responses of adult males are mediated by a blend of volatile female sex pheromone compounds, (Z)-3 hexenyl acetate and (E)-2-hexenol, at a ratio of 1:5. This female sex pheromone blend may be useful for tea mosquito control and management programs.

MDT-MB therapy in paucibacillary leprosy: a clinicopathological assessment

BACKGROUND

The World Health Organization recommends treatment regimens for paucibacillary (PB) and multibacillary (MB) leprosy, which differ in their duration and components. Hence accurate classification of the disease is required. To overcome difficulties in classification Uniform Multi Drug Therapy (U-MDT) has been recommended.

AIM

To evaluate the benefit of adding clofazimine to paucibacillary regimens in leprosy patients by measuring clinical and histological resolution.

METHODS

Forty-four paucibacillary patients were included in the study. Twenty-two patients were given MDT-PB regimen and the remaining MDT-MB regimen for six months . Skin biopsies were done before the commencement and at the end of treatment. Clinical and histological resolutions were measured according to the standard criteria a laid down. The results were analyzed using Fishers' test and Crammers' V test.

RESULTS

Clinical improvement was observed in 90.9% in the MB group as compared to 27.3% in the PB group. Regression in the nerve swelling was observed in 70% in the MB group and in 37.5% in the PB group while histological resolution was observed in 72.8% and 54.5% respectively.

CONCLUSIONS

Addition of clofazimine helps to resolve leprosy lesions both clinically and histologically, thus justifying the concept of Uniform MDT regimen for all patients.

Polycystic kidneys and del (4)(q21.1q21.3): further delineation of a distinct phenotype

A three year-old boy was evaluated because of growth and developmental delay, hypotonia and dysmorphic features. G-banding analysis revealed a small interstitial deletion of the long arm of chromosome four described as 46,XY,del (4)(q21.1q21.3). This patient's findings on physical exam included relative macrocephaly, frontal bossing, short fingers with clinodactyly and were consistent with the phenotypes of previously reported deletions involving the 4q21--> 4q22 band region (Am. J. Med. Genet. 68 (1997) 400-405). To date there are 10 reported live-born cases with such deletions and similar features. The case reported here delimits a minimal critical region for this phenotype to chromosomal region 4q21. Our patient was also found to have cysts in both his kidneys. The gene for type II polycystic kidney disease (PKD2) has been mapped to chromosomal region 4q21--> 4q23. FISH analysis, with a probe including the PKD2 gene, demonstrated hemizygosity at this locus. Thus the absence of one of the PKD2 alleles in the case reported here is associated with early bilateral cyst development. Kidney ultrasound/autopsy studies were reported in seven of the patients with the characteristic phenotype, and were positive for cysts in four cases including the one presented here (Clin. Genet. 31 (1987) 199-205; Am. J. Med. Genet. 68 (1997) 400-405; Am. J. Med. Genet. 40 (1991) 77-790. Our report supports the presence of a distinct phenotype associated with a deleted chromosomal region within 4q21. Hemizygosity for the PKD2 gene is likely in such deletions and may lead to renal cyst formation.

Sources of semiochemicals mediating host finding in Callosobruchus chinensis (Coleoptera: Bruchidae)

Bruchid pests such as Callosobruchus chinensis (Linnaeus) endanger stored legume seeds throughout the tropical belt. The chemical composition of the headspace volatiles from healthy and fourth instar larvae-infested cowpea seeds were identified, characterized, and compared using gas chromatography-mass spectrometry. Y-tube olfactometer bioassays were performed to evaluate the effect of these chemicals on the orientation of conspecific adult females. Analysis of volatiles released from healthy and infested seeds revealed qualitative differences for three out of the 17 compounds identified. Dimethyl disulphide, isobutenyl methyl ketone and methyl trisulphide were found only in the blend emitted from infested but not from healthy seeds. Quantitative differences were apparent for tridecane which was released in larger amounts from infested seeds. While volatiles collected from healthy seeds were attractive to female bruchids, volatiles collected from infested seeds were repellent. To test the hypothesis that the qualitative differences in the chemical composition found may be due to insect-derived components, the volatiles from frass and fourth instar larvae combined were analysed. These volatiles contained both of the sulphides emitted from infested seed but not from healthy seeds. Although a limited induction of volatiles from cowpea seeds cannot be excluded, it is postulated that behavioural differences of the female weevils are largely due to insect-derived semiochemicals. The potential use of such semiochemicals as part of an integrated pest management strategy is discussed.

[The signal-averaged ECG in long-term monitoring of patients with fulminant myocarditis]

A case of a 24 year-old patient with fulminant myocarditis is described. The lymphocytic myocarditis was proved by endocardial biopsy. The patient had been followed for 15 months clinically, by transthoracic ultrasound and by the signal averaged ECG. The clinical and ultrasound parameters of the left ventricular systolic dysfunction subsided within 6 months, STT changes on the routine 12-lead ECG within 2 months. On the signal-averaged ECG, changes were observed in both the time and in the frequency domain. When the results of the initial examination (6 weeks after the beginning of the disease) were compared with the examination at the 7th month of the disease there was a prolongation of the QRS duration (from 95 ms to 104 ms), prolongation of the duration of the filtered ECG below 40 microV (from 21.5 to 36.2 microV) and the decrease of the total sum of the potential in the terminal part of the QRS. Most apparent was the decrease in the total sum of the high-frequency components (filter 70-250 Hz) of the QRS (RMSt: from 53.3 microV to 37.9 microV at the same noise level). In contrast to the changes in the time domain parameters there was no tendency in improvement of the RMSt. In patients with myocarditis the signal averaged ECG may prove to be a suitable tool for the long-term follow-up of the subclinical structural abnormalities of the left ventricular wall.

[Dysfunction of a valve prosthesis]

The authors describe the case of a haemodynamically unstable patient with dysfunction of a valvular prosthesis which was resolved by emergency surgery. In the discussion they deal with two basic causes of these dysfunctions and their possible solutions.

Efficacy of crude extracts of Andrographis paniculata nees. on Callosobruchus chinensis L. during post harvest storage of cowpea

Bioefficacy of different solvent fractions of A. paniculata was tested against the cowpea weevil, C. chinensis in terms of its effect on adult mortality, total egg output and emergence of F1 adults. All the extracts were effective against the weevil, the efficacy was however more significant with respect to methanol and ethyl acetate extracts at the highest concentrations (1,000 ppm) which lead to 72.01 and 67.69% adult mortality respectively. The efficacy was dose dependent. Total egg and percent emergence of Fl adults were lowest for methanol followed by ethyl acetate fractions. Possible role of the principal chemical constituents of this plant in bringing about mortality of the pest, reduction in egg laying and adult emergence are discussed.

Evaluation of efficacy and safety of losartan potassium in the treatment of mild to moderate hypertension as compared to enalapril maleate

AIM

To study the effect of losartan potassium in the treatment of mild to moderate hypertension and to compare its efficacy and adverse effect profile with enalaparil maleate.

MATERIAL AND METHODS

One hundred and forty five patients with mild to moderate essential hypertension were enrolled in this randomized, double blind, controlled, parallel and multicentric study. Seventy two patients received losartan potassium 50 mg and seventy three received enalapril maleate 5 mg.

RESULTS

Losartan potassium reduced the DBP to < 90 mm Hg in 59% of the patients at the end of 8 weeks compared to 45% in the enalapril maleate group. DBP was reduced by 10 or > than 10 mm Hg in 89% of the patients with losartan as compared to the baseline whereas it was 80% in the enalapril group. Percentage of side effects seen in losartan and enalapril groups were 12 and 22 respectively.

CONCLUSION

Losartan potassium is an efficacious antihypertensive agent in mild to moderate hypertension. It also has fewer side effects when compared to enalapril maleate.

Prenatal diagnosis and outcome of mosaicism for a de novo unbalanced translocation identified in amniocytes

Mosaicism for an unbalanced reciprocal translocation was identified in cultured amniocytes of a 16-week-old fetus; mos46,XX,der(4)t(4;5)(q34;q12)/46,XX. Parental karyotypes were normal, indicating a de novo origin of the unbalanced translocation in the fetus. The additional chromosomal material on the der(4) was derived from chromosome 5 as demonstrated by both GTG banding and fluorescence in situ hybridization with a chromosome 5 paint. Two subsequent amniocenteses, at 18 and 20 weeks, confirmed the presence of the abnormal cell line. A percutaneous umbilical blood sample (PUBS) contained only normal cells, 46,XX, and a high resolution ultrasound revealed no fetal abnormalities or growth retardation. The pregnancy was continued and a normal female was born at term. No evidence of the unbalanced translocation cell line was found in cord blood or placental samples at birth. The finding of mosaicism for an unbalanced translocation at amniocentesis is rare, and is associated with a high risk of fetal abnormality. This case illustrates the importance of follow-up studies by PUBS and high-resolution ultrasound for further assessing the risk of phenotypic abnormality.

Homozygosity for pericentric inversions of chromosome 9. Prenatal diagnosis of two cases

The finding of homozygosity for a pericentric inversion of chromosome 9 [inv(9)] is rare, and previously has not been reported at prenatal diagnosis. We describe two unrelated cases of homozygosity for inv(9) identified in amniocytes. In each case, both parents were heterozygotes for the inv(9); 46,XX,inv(9)(p11q13) and 46,XY,inv(9) (p11q13). Case 1 resulted in a normal term infant who at age 5 years was phenotypically and developmentally normal. Case 2 was referred for severe intrauterine growth retardation (IUGR) and oligohydramnios, and subsequently expired in utero. Even though inv(9) is a normal chromosome variant with a frequency of 1 to 3% in the general population, the finding of homozygosity for inv(9) and IUGR in this fetus suggested the possibility of uniparental disomy (UPD). Molecular studies confirmed the presence of both parental inv(9) chromosomes, excluding the possibility of chromosome 9 UPD as the cause of IUGR in this fetus. Presumably, inv(9) homozygosity results from the high frequency of inv(9) heterozygosity, and is a normal variant. However, until the effects of UPD for chromosome 9 are established, parental karyo types and, where appropriate, molecular studies should be performed to exclude UPD. In addition, more reports of inv(9) homozygosity detected prenatally are needed to assess its frequency and outcome.

Prenatal diagnosis of a familial interchromosomal insertion of Y chromosome heterochromatin

An apparently unbalanced karyotype containing an abnormal chromosome 11 was identified in a 16-week female fetus by analysis of cultured amniocytes. Fluorescence in situ hybridization (FISH) with a chromosome 11 paint identified the presence of an insertion in band 11q24. Parental karyotyping documented an unbalanced karyotype with the same der(11) chromosome in the phenotypically normal father. CBG-banding and FISH identified the insertion to be Yq12 heterochromatin: 46,XY, der(11)ins(11;Y)(q24;q12q12).ish der(11) (wcp11+,DYZ1+). The same der(11) chromosome was also found in the phenotypically normal paternal grandmother, demonstrating this additional Y chromosomal material did not affect normal female sexual development or fertility. The parents elected to continue the pregnancy and a normal girl was born at term, further confirming that this rare familial variant has no clinical significance. This case illustrates the importance of family studies, appropriate banding, and FISH analyses to accurately characterize apparent chromosomal abnormalities.

Mosaicism for a small supernumerary ring X chromosome in a dysmorphic, growth-retarded male: mos47,XXY/48,XXY, +r(X)

Supernumerary ring X [r(X)] chromosomes are often found in patients with Turner syndrome. The phenotypic effects of the r(X) chromosome are variable, and largely depend on the presence or absence of the X inactivation (XIST) locus. Ring(X) chromosomes in males are rare and have been previously reported in only four cases, with 47,XY, + r(X) or mos47,XY, +r(X)/46,XY karyotypes. These patients all had developmental delay and dysmorphic features. We describe a 2.5-year-old male patient with facial dysmorphia, growth retardation, microcephaly, global developmental delay, and microphallus. Cytogenetic analysis from peripheral blood lymphocytes and fibroblasts identified mosaicism for two cell lines: mos48,XXY, + r(?X)/47,XXY. Fluorescence in situ hybridization (FISH) with an X chromosome paint showed the ring chromosome to be X chromosome derived. This is the first case of an r(X) chromosome described in a 47,XXY patient. FISH analysis of the r(X) chromosome with an XIST probe showed that the XIST locus was absent. Functional disomy of genes in the r(X) chromosome most likely accounts for the abnormal phenotype in the proband.

Prenatal detection and molecular characterization of a de novo duplication of the distal long arm of chromosome 19

A tandem duplication of the distal long arm of chromosome 19 was identified in a 10 week fetus by analysis of chorionic villi. The fetal karyotype from two primary cultures was 46,XY,dir dup(19)(q13.2q13.4). The origin of the extra material was confirmed by fluorescence in situ hybridization using a chromosome 19 whole chromosome probe. Parental chromosomes were normal, indicating a de novo origin of the extra chromosome material. This is the first case of dup(19q) detected by prenatal diagnosis. Molecular studies demonstrated that the duplication involved a maternal chromosome 19.