Dynamics of conjunctival impression cytologic changes after vitamin A supplementation

To investigate the chronological changes in conjunctival epithelium after supplementation with a massive oral dose of vitamin A, conjunctival impression cytology (CIC) with transfer was carried out repeatedly among 200 children aged 6-120 months in a randomized, double-blind, placebo-controlled study in Chandigarh (India). Significant conversion to normal CIC started 71-80 d after vitamin A supplementation and by 101-110 d conversion had taken place in all children. Compared with the placebo group, plasma retinol concentration at 100 d post-supplement was found to be significantly higher in the vitamin A-supplemented group P = 0.04. This study demonstrates that CIC responds to a massive oral dose of vitamin A 3-4 months after supplementation. These findings should guide future studies and evaluations in which CIC is used to assess response to vitamin A interventions.     

Treatment with interleukin-4 prolongs allogeneic neonatal heart graft survival by inducing T helper 2 responses

BACKGROUND: Eosinophils are a prominent feature of chronic hyperplastic sinusitis with nasal polyposis (CHS/NP). Our previous studies showed that their presence was associated with the expression of GM-CSF and RANTES mRNA. In allergic NP, increased expression of IL-5 was also found. OBJECTIVE: We wished to examine cytokine immunoreactivity for IL-5, GM-CSF and RANTES mRNA in allergic and non-allergic NP and compare immunoreactivity with expression of cytokine mRNA by in situ hybridization. Methods NP were obtained from five allergic and eight non-allergic subjects with CHS/ NP. Middle turbinate tissue from eight normal subjects were used as controls. Cell-associated cytokine mRNA was detected by in situ hybridization (ISH). Cytokine immunoreactive cells were enumerated by immunostaining. Colocalization immunostaining was also performed to identify specific cell types producing IL-5. RESULTS: Immunostaining for GM-CSF, IL-5 and RANTES protein was increased in both allergic and non-allergic NP compared with control middle turbinates. Allergic polyps contained greater numbers of IL-5 immunoreactive cells (P = 0.01), whereas non-allergic polyps contained greater numbers of GM-CSF immunoreactive cells (P = 0.04). Immunostaining was primarily associated with inflammatory cells, but immunostaining for RANTES and, to a lesser extent GM-CSF, was also seen in the epithelium. The density of immunoreactive cells was variably correlated with cytokine mRNA+ cells (GM-CSF: R=0.56, P=0.05; IL-5: R=0.76, P=0.003; and RANTES: R=0.89, P=0.0005). Colocalization immunostaining revealed that the majority of IL-5 immunoreactive cells in both allergic and non-allergic NP were T lymphocytes. However, allergic NP contained greater numbers of IL-5+/CD3+ T lymphocytes and IL-5+ mast cells, whereas non-allergic NP contained greater numbers of IL-5+ eosinophils. CONCLUSION: We conclude that GM-CSF, IL-5 and RANTES are produced in increased amounts in both allergic and non-allergic NP. Distinguishing features of non-allergic NP include fewer numbers of CD3 T lymphocytes, fewer IL-5+/CD3+ T lymphocytes and greater numbers of IL-5+ eosinophils. These differences may suggest different mechanisms of eosinophil accumulation and activation in allergic vs non-allergic NP.     

Haemorrhagic septicaemia vaccines

Haemorrhagic septicaemia (HS), an economically important disease of cattle and buffaloes, is caused by Pasteurella multocida (6:B). Vaccination against this disease is widely practised. Plain broth bacterins, or alum precipitated and aluminium hydroxide gel vaccines are administered twice a year since these vaccines offer an immunity of 4-6 months. Many countries use oil adjuvant vaccine (OAV), which gives both a higher degree and a longer duration of immunity up to 1 year. A double emulsion and multiple emulsion vaccine consisting of a thin viscosity have also been experimentally developed that gave an immunity parallel to OAV. Recently, a live vaccine developed from a fallow deer strain (B:3,4) has been used in Myanmar that offers an immunity for more than a year but is not free from constraints. The present review provides information on HS vaccines developed from time to time using whole bacteria or their components. The kinetics and isotype of antibody and cell-mediated immune responses have also been poorly understood so far, and hence information on their role in protection against HS is reviewed.     

Characterization of superplastic deformation behavior of a fine grain 5083 Al alloy sheet

Superplastic deformation behavior of a fine grain 5083 Al sheet (Al-4.2 pct Mg-0.7 pct Mn, trade name FORMALL 545) has been investigated under uniaxial tension over the temperature range of 500 °C to 565 °C. Strain rate sensitivity values >0.3 were observed over a strain rate range of 3 × 10⁻⁵ s⁻¹ to 1 × 10⁻² s⁻¹, with a maximum value of 0.65 at 5 × 10⁻⁴ s⁻¹ and 565 °C. Tensile elongations at constant strain rate exceeded 400 pct; elongations in the range of 500 to 600 pct were obtained under constant crosshead speed and variable strain rates. A short but rapid prestraining step, prior to a slower superplastic strain rate, provided enhanced tensile elongation at all temperatures. Under the two-step schedule, a maximum tensile elongation of 600 pct was obtained at 550 °C, which was regarded as the optimum superplastic temperature under this condition. Dynamic and static grain growth were examined as functions of time and strain rate. It was observed that the dynamic grain growth rate was appreciably higher than the static growth rate and that the dynamic growth rate based on time was more rapid at the higher strain rate. Cavitation occurred during superplastic flow in this alloy and was a strong function of strain rate and temperature. The degree of cavitation was minimized by superimposition of a 5.5 MPa hydrostatic pressure during deformation, which produced a tensile elongation of 671 pct at 525 °C. R. VERMA, formerly Visiting Scientist, Department of Materials Science and Engineering, University of Michigan     

Cytogenetic investigations on patients with oral submucous fibrosis

Lymphocyte cultures were set up from venous blood samples collected from 23 patients of submucous fibrosis (SMF) and 10 normal controls. Slides, thus prepared, were processed and screened for G-, C-banding and sister chromatid exchange (SCE) frequency analysis. No gross chromosomal anomalies except that a few breaks and gaps were observed to be randomly distributed throughout the genome. However, a proportionate increase in SCE frequency in SMF patients as compared to the normal control individuals was observed. An attempt has been made to correlate the period of betel leaves, nuts, quid and tobacco chewing with the incidence of chromosomal anomalies and increase in SCE frequency and its sexwise distribution in these patients.     

Importance measures in ranking piping components for risk informed in-service inspection

Risk informed in-service inspection aims at prioritising the components for inspection within the permissible risk level thereby avoiding unnecessary inspections. Various methods have been evolved for prioritisation, in which the importance measure approach has gained a wide popularity. This paper presents an importance measure that can be employed to prioritise components of any dimension, which is normally required from the point of view of carrying out a risk informed in-service inspection of nuclear power plants.     

Diagnostic acceptability of FFT-based ECG data compression

There are three signal domains in which ECG data compression can be performed, namely time domain, frequency domain and parameter extraction. The present paper deals with the frequency domain method of compression using fast Fourier transform. The algorithm has been tested on the third set of the CSE database library. A performance evaluation has been made using two important parameters, namely compression ratio and percent root-mean-square difference besides visual comparison. Further, in order to know the clinical acceptable quality of the reconstructed signal peak, boundary and interval measurements were made both on the reconstructed and the original signal of the same record for comparison. The visual examination reveals that most of the noise in the original signal had been filtered out during the compression. This amounts to reduction of electromyographic noise to a considerable extent. The experimental observations show that a compression ratio of 8 is feasible while ensuring clinical acceptability.     

Teenage primigravidae: a comparative study

A review of history sheets of obstetric cases recorded in a district hospital in 1992 was done to compare the obstetric outcome in 200 teenage first pregnancies (Study group) with that in Control group i.e. 20 years to 29 years. It revealed that incidence of complications of pregnancy like anaemia, pregnancy induced hypertension (PIH) and preterm labour were significantly higher among teenage mothers. The normal mode of delivery was commoner in teenagers (82.5%) in comparison to control group (76.5%), probably because of higher number of low birth weight babies. The fetal outcome was significantly worse in teenage mothers with high incidence of perinatal mortality (8%) and low birth weight babies (35%). There was not a single newborn with birthweight above 3500 gms, in teenage group, whereas, control group had 5 babies (2.5%) in the category.     

An experimental cum numerical technique to determine dynamic interlaminar fracture toughness

A method combining experimental and finite element analysis is developed to determine interlaminar dynamic fracture toughness. An interlaminar crack is propagated at very high speed in a double cantilever beam (DCB) specimen made of two steel strips which are bonded together by epoxy with a precrack of about 40 mm length. The face of the front cantilever is bonded to a large solid block and a special fixture is designed to apply impact load to the rear cantilever through a load bar. In the load bar, a compressive square shaped elastic stress pulse is generated by impacting it with a striker bar which is accelerated in an air gun. The rear cantilever is screwed to the load bar; when the incident compressive pulse reaches the specimen, a part of the energy is reflected into the load bar and the rest of it passes to the specimen. By monitoring the incident and the reflected pulses in the load bar through strain gauges, deflection of cantilever-end is determined. The crack velocity is determined by three strain gauges of 0.2 mm gauge length bonded to the side face of the rear cantilever. Further, the first strain gauge, bonded very close to the tip of the precrack, and the crack velocity determine the initiation time of crack propagation.

The experimental results are used as input data in a finite element (FE) code to calculate J-integral by the gradual release of nodal forces to model the propagation of the interlaminar crack. The initiation fracture toughness and propagation fracture toughness are evaluated for an interlaminar crack propagating with a velocity in the range of 850 to 1785 m/s. The initiation toughness and propagation toughness were found to vary between 90–200 J/m² and 2–13 J/m², respectively.     

A comprehensive framework for evaluation of piping reliability due to erosion–corrosion for risk-informed inservice inspection

Mathematical models described by multivariable functions f(x) where x=(x₁,…,x_n) are investigated. If the model output is influenced mainly by low order combinations of input variables x₁,…,x_n, an attempt can be made to construct a low order approximation to the model using values of f(x) only.