Using a random laser to measure the content of protein in skim milk

The luminescence of skim milk samples with distinct protein content doped with rhodamine B was investigated. The samples were excited by a nanosecond laser tuned at 532 nm, and the emission was characterized as a random laser. Its features were analyzed as a function of the protein aggregate content. The results showed a linear correlation between the random laser peak intensity and the protein content. This paper proposes a rapid detection photonic method to evaluate the protein content in skim milk based on the intensity of the random laser emission.

Chitosan-functionalized nanostructured lipid carriers containing chloroaluminum phthalocyanine for photodynamic therapy of skin cancer

The objective of this study was to obtain optimized nanostructured lipid carriers (NLC) functionalized with chitosan containing chloroaluminum phthalocyanine (ClAlPc) as a photosensitizer. Initially, the optimization of the preparation method of the NLC was performed, where the influence of different surfactants such as PVA and Tween 80, as well as different solid lipids such as stearic acid and Glycerol Monostearate (GM) was evaluated. The formulation containing GM and PVA (NLC10) was considered promising. Following, by the adsorption method (NLC10q), the formulation was functionalized with chitosan and characterized. NLC10 and NLC10q presented sizes of 131.5 and 231.5 nm, and ZP of -24.30 and + 19.96 mV, respectively. The encapsulation efficiency of NLC10q was 96 %, higher than NLC10 (79 %). The formulations were able to promote significant cutaneous retention of ClAlPc, after 2 h and 4 h of the study, and showed to be non-toxic to fibroblasts (biocompatible). PDT in BF16-F10 melanoma resulted in reduced cell viability to 70 % and 50 % for NLC10 and NLCq, respectively. In view of the results obtained, NLC showed to be promising in the treatment of skin cancer through PDT. NLC10q showed higher encapsulation efficiency and stability than NLC10, but, contrary to what was expected, it presented lower photodynamic efficiency.

Chalcone-based molecules: Experimental and theoretical studies on the two-photon absorption and molecular first hyperpolarizability

Five chalcone-based molecules denominated by C-3 ((E)-1-(4-methoxyphenyl)-3-phenylprop-2-en-1-one), C-4 ((E)-1,3-bis(4-methoxyphenyl)prop-2-en-1-one), C-5 ((E)-1-(benzo[d][1,3]dioxol-5-yl)-3-(4-methoxyphenyl)prop-2-en-1-one), C-6 ((E)-3-(naphthalen-1-yl)-1-phenylprop-2-en-1-one) and C-7 ((E)-1-(4-methoxyphenyl)-3-(naphthalen-1-yl)prop-2-en-1-one) were synthesized by Claisen-Schmidt reaction in solution of NaOH in water/ethanol 2:1. The aldehydes used were benzaldehyde, anisaldehyde, and β-naphthaldehyde, while the used ketones were acetophenone, p-methoxyacetophenone, and 3,4-methylenedioxyacetophenone. Z-scan and hyper-Rayleigh scattering techniques were used to study the nonlinear optical properties of these compounds in dichloromethane medium. By using Z-scan technique with femtosecond pulses, two-photon absorption cross-sections (σ^TPA) were determined, while the first molecular electronic hyperpolarizabilities (β^HRS) were evaluated by the hyper-Rayleigh scattering technique, with picosecond pulses. From the recorded two-photon absorption spectra, it was identified that compound C-7 presented the highest σ^TPA, regarding the HOMO-LUMO transition, with a value of 40 GM, while C-6 achieved the lowest value for the same transition with 13 GM. Concerning the values of the first molecular hyperpolarizability, compound C-4 presented the highest value, 38 × 10^-30 cm⁴ statvolt^-1, while C-3 presented the lowest β^HRS value of about 16 × 10^-30 cm⁴ statvolt^-1. Time-dependent density functional theory calculations were used to simulate the one- and two-photon absorption spectra, as well to predict the theoretical value of β^HRS in dichloromethane and vacuum medium.

Serological Immunoglobulin G antibody titers to Helicobacter pylori in Japanese Brazilian and Non-Japanese Brazilian gastric cancer patients and controls in São Paulo

Helicobacter pylori (H. pylori) infection is considered a cause of gastric cancer (GC), though evidence for this association is scarce in high-risk areas. Possible case control and/or ethnic differences were investigated as to the presence of H. pylori and its immunogloblin G antibody titer in the multi-ethnic city of São Paulo, where the incidence of GC is relatively high. We performed a cross-sectional comparison of antibody titers to H. pylori in Japanese Brazilian, and non-Japanese Brazilian GC patients and their controls. Japanese Brazilian patients were matched by age, sex and ethnicity with two controls, while non-Japanese Brazilian patients were matched as above with one control. Among Japanese Brazilians, 59 of 93 (63.4%) patients with GC and 127 of 186 (68.3%) controls were positive for H. pylori-specific antibody (odds ratio (OR) = 0.80, 95% confidence interval (CI) = 0.47 - 1.36), while among non-Japanese Brazilians, 171 of 228 patients with GC (75.7%) and 178 of 226 controls (78.8%) were positive (OR = 0.84, 95% CI = 0.54 - 1.30). The median serum antibody titer was lower in cases than in controls in both ethnic groups. A high titer (H. pylori titer > or = 50) was associated with less likelihood of GC for both ethnic groups (for Japanese Brazilians, OR = 0.39, 95% CI = 0.16 - 0.92; for non-Japanese Brazilians, OR = 0.56, 95% CI = 0.31 - 1.02). The high titer can be regarded as a sign of the necessity of eradication, and low titer is regarded as a sign of the necessity of close screening for GC in both ethnic groups, because extended atrophy may cause spontaneous disappearance of H. pylori from the stomach.

Echinococcus granulosus: Cloning and Functional in Vitro Characterization of an Actin Filament Fragmenting Protein

We report the isolation and characterization of an Echinococcus granulosus gene that codes for a protein with actin filament fragmenting and nucleating activities (EgAFFP). The genomic region corresponding to the EgAFFP gene presents a coding sequence of 1110 bp that is interrupted by eight introns. The EgAFFP deduced amino acid sequence is about 40% homologous to those of several members of the gelsolin family, such as Physarum polycephalum fragmin, Dictyostelium discoideum severin, and Lumbricus terrestris actin modulator. As do other proteins of the same family, EgAFFP presents three repeated domains, each one characterized by internal conserved amino acid motifs. Assays with fluorescence-labeled actin showed that the full-length recombinant EgAFFP effectively binds actin monomers in both a calcium-dependent and calcium-independent manner and also presents actin nucleating and severing activities.

Increasing trend of HIV seroprevalence among pulmonary tuberculosis patients in Pune, India

A total of 4618 tuberculosis patients attending the TB clinic at the Sassoon General Hospitals, Pune between 1991 and 1996 were screened for anti-HIV antibodies. Of these 694 were found reactive in enzyme immuno assay (EIA) and 624 were further confirmed by a second test, either rapid EIA or Western blot. HIV-1 reactivity was predominant among tuberculosis patients with HIV-2 reactivity appearing only in 1995. HIV-2 seroreactivity accounted for 0.54 and 1.02 per cent of all HIV reactive samples in 1995 and 1996. HIV-1 and HIV-2 dual reactivity accounted for 1.63 and 2.04 per cent of all infections in 1995 and 1996. The overall seroprevalence of HIV among newly diagnosed tuberculosis patients rose from 3.2 per cent in 1991 to 20.1 per cent in 1996.

A protein with a novel calcium-binding domain associated with calcareous corpuscles in Echinococcus granulosus

A novel intracellular calcium-binding protein from Echinococcus granulosus is described in this work. A cDNA was isolated from a lambdagt11 protoscolex expression library and the deduced amino acid sequence has at least fifteen sequentially repeated twelve-residue repeats that resemble the calcium-binding loop of EF-hands; however, the dodecamer motif has no flanking helices. The cDNA was expressed in Escherichia coli using the pGEX vector, and a recombinant fusion protein (EgCaBP1-GST) was obtained. The recombinant fusion protein binds calcium when assayed with 45Ca. It is possible that the calcium-binding motifs present a secondary structure similar to the parallel beta roll structure described for an alkaline protease from Pseudomonas aeruginosa. A native protein of more than 300 kDa was recognized by an anti-EgCaBP1 monoclonal antibody by Western-blot analysis. Immunohistochemistry using a pool of anti-EgCaBP1-GST mouse sera demonstrated a strong association of the protein with calcareous corpuscles. The possible role of this protein and that of the calcareous corpuscles in the protoscolex are discussed.

Evidence for high prevalence & rapid transmission of HIV among individuals attending STD clinics in Pune, India

Prevalence and incidence of HIV-1 infection among persons attending two STD clinics in Pune between May 1993 and October 1995 are reported. On screening 5321 persons, the overall prevalence of HIV-1 infection was found to be 21.2 per cent, being higher in females (32.3%) than in males (19.3%). Analysis of behavioural and biological factors showed that old age, sex work, lifetime number of sexual partners, receptive anal sex, lack of circumcision, genital diseases and lack of formal education were related to a higher HIV-1 seroprevalence. The observed incidence rate of 10.2 per cent per year was very high, much higher in women than in men (14.2% and 9.5% per year respectively) and over three times higher among the sex workers. Females in sex work, males having recent contacts with female sex workers (FSWs) and living away from the family and persons with previous or present genital diseases had a higher risk of seroconversion. Condom usage was shown to have a protective effect in seroprevalence and seroincidence analysis. With limited available resources and lack of a suitable vaccine or a drug, long-term prevention policy of creating awareness in the community must be supplemented by strengthening STD control measures and promotion of condom use and safe sex. Factors related to availability and utilization of condoms must be carefully investigated.

Mimicry of the calcium-induced conformational state of troponin C by low temperature under pressure

Calcium binding to the N-domain of troponin C initiates a series of conformational changes that lead to muscle contraction. Calcium binding provides the free energy for a hydrophobic region in the core of N-domain to assume a more open configuration. Fluorescence measurements on a tryptophan mutant (F29W) show that a similar conformational change occurs in the absence of Ca2+ when the temperature is lowered under pressure. The conformation induced by subzero temperatures binds the hydrophobic probe bis-aminonaphthalene sulfonate, and the tryptophan has the same fluorescence lifetime (7 ns) as in the Ca2+-bound form. The decrease in volume (delta V = -25.4 ml/mol) corresponds to an increase in surface area. Thermodynamic measurements suggest an enthalpy-driven conformational change that leads to an intermediate with an exposed N-domain core and a high affinity for Ca2+.

Absence of wild poliovirus circulation among healthy children in a rural area with high oral poliovirus vaccination coverage

Poliovirus circulation in a rural community was studied by a stool sample survey. No acute paralytic poliomyelitis case had been reported from the study area during the previous 5 months. Immunization coverage in age groups 7 to 12 months and 12 to 60 months was 95.8 and 94 per cent, respectively. Of the 257 children from whom stool samples were collected (about 6% of the child population), 161 (62.6%) were positive for virus isolation. Poliovirus was isolated from 60 (23.3%) children. All three poliovirus types were detected (41 type 1, 16 type 2 and 3 type 3). Intratypic differentiation tests classified these isolates as vaccine-like. Among the children excreting poliovirus, the proportion of those who did not receive polio vaccine within 30 days prior to the sample collection was 46.3, and 68.7 per cent for poliovirus type 1 and 2, respectively. It was concluded that these poliovirus excreting children were infected by the vaccine strains circulating in the environment. The survey showed that wild poliovirus was not detectable within five months after the last case of acute poliomyelitis. Displacement of the wild virus from the environment and circulation of vaccine virus was achieved by high vaccination coverage in this area.

Incidence and predictors of human immunodeficiency virus type 1 seroconversion in patients attending sexually transmitted disease clinics in India

The first estimates of the seroincidence of human immunodeficiency virus type 1 (HIV-1) and of the risk factors for seroconversion in a cohort of high-risk patients attending sexually transmitted disease (STD) clinics in India are reported. Between 1993 and 1995, 851 HIV-1-seronegative persons were evaluated prospectively every 3 months for HIV infection and biologic and behavioral characteristics. The overall incidence of HIV-1 was 10.2/100 person-years (95% confidence interval, 7.9-13.1). The incidence among commercial sex workers (CSWs) was 26.1/100 person-years, compared with 8.4 among non-CSWs. Recurrent genital ulcer disease and urethritis or cervicitis during the follow-up period were independently associated with a 7- (P < .001) and 3-fold (P = .06) increased risk of HIV-1 seroconversion, respectively. Because of the association of recurrent ulcerative and nonulcerative STDs with HIV-1 seroconversion in this setting, behavioral and biologic measures directed at the prevention and control of STDs would be expected to greatly reduce the transmission of HIV-1 infection in similar high-risk groups.

An evaluation of cold chain in Maharashtra & Karnataka states by potency testing of field samples of oral poliovirus vaccine

The cold chain for oral poliovirus vaccine was monitored in Maharashtra and Karnataka by potency testing of vaccine vials collected from various stages of the delivery system. Results showed that cold chain maintenance improved in the state of Maharashtra within a period of three years as the monitoring began in 1987. Of the 6289 samples of trivalent OPV collected from all 30 districts of the state during 1990 to 1992, 5834 (92.8%) had retained virus titre of at least 10(5.81) TCID50/dose. In comparison, 72 per cent of the 1660 samples collected from the state of Karnataka during the same period were found to contain this minimum required virus titre. Defects in cold chain maintenance in Karnataka could be demonstrated by plotting virus titre of samples of individual batches collected from different outlets. It was concluded that potency retesting of OPV samples for cold chain monitoring will ensure proper storage, transport and use of potent vaccine in the field.

Risk factors for HIV infection in people attending clinics for sexually transmitted diseases in India

OBJECTIVE

To investigate the risk factors for HIV infection in patients attending clinics for sexually transmitted diseases in India.

DESIGN

Descriptive study of HIV serology, risk behaviour, and findings on physical examination.

SUBJECTS

2800 patients presenting to outpatient clinics between 13 May 1993 and 15 July 1994.

SETTING

Two clinics and the National AIDS Research Institute, in Pune, Maharashtra State, India.

MAIN OUTCOME MEASURE

HIV status, presence of sexually transmitted diseases, and sexual behaviour.

RESULTS

The overall proportion of patients infected with HIV was 23.4% (655/2800); 34% (184) of the women and 21% (459) of the men were positive for HIV infection. Of the 560 women screened, 338 (60%) had a reported history of sex working, of whom 153 (45%) were infected with HIV-1. The prevalence of HIV-1 infection in the 222 women who were not sex workers was 14%. The significant independent characteristics associated with HIV infection based on a logistic regression analysis included being a female sex worker, sexual contact with a sex worker, lack of formal education, receptive anal sex in the previous three months, lack of condom use in the previous three months, current or previous genital ulcer or genital discharge, and a positive result of a Venereal Disease Research Laboratory test.

CONCLUSIONS

In India the prevalence of HIV infection is alarmingly high among female sex workers and men attending clinics for sexually transmitted diseases, particularly in those who had recently had contact with sex workers. A high prevalence of HIV infection was also found in monogamous, married women presenting to the clinics who denied any history of sex working. The HIV epidemic in India is primarily due to heterosexual transmission of HIV-1 and, as in other countries, HIV infection is associated with ulcerative and non-ulcerative sexually transmitted diseases.

Prevalence of antibodies to polioviruses & enteroviruses excreted by healthy children in Bombay

A total of 132 healthy children between the ages one month and 12 yr were surveyed to determine the prevalence of antibodies to the three poliovirus serotypes. Among infants up to six months of age, 73.2, 85.4 and 56.1 per cent had antibodies to poliovirus types 1, 2 and 3, respectively. In children of age groups 7 months to 3 yr and above 3 yr, antibody prevalence to the three poliovirus serotypes was 90.2, 86.9 and 57.4, and 83.3, 96.7 and 76.7 per cent, respectively. Immunization coverage with three doses of OPV exceeded 85 per cent in children above 7 months of age. Low seroprevalence to type 3 poliovirus in the children was conspicuous. Of the 80 faecal samples studied from these children, 24 (30%) were positive for virus. Among these isolates, 16 were poliovirus type 1 and three type 2. Intratypic differentiation revealed that 15 of the 16 poliovirus type 1 isolates were of wild origin. Two out of the three poliovirus type 2 isolates were of oral poliovaccine origin. Our data indicate that in spite of good vaccination coverage wild poliovirus type 1 circulation was endemic in Bombay and; that a large number of children were susceptible to poliovirus type 3 infections.

Cell lines used for the selection of recombinant baculovirus

Four insect cell lines were used to isolate two recombinant baculoviruses which had the beta-galactosidase (beta-gal) gene for colorimetric assay purposes. Plaque assays were performed using two Trichoplusia ni cell lines: BTI-TN-5B1-4 and TN-368, and two Spodptera frugiperda cell lines: IPLB-SF-21AE and SF9. The number of plaques (occlusion positive and blue beta-gal+ recombinants) formed in the Trichoplusia cells was higher than in the Spodoptera cells. The appearance of Autographa californica NPV polyhedra was also faster in the T. ni cell lines. The effect of cell passage on the plaque formation proved to be critical when two different passages of the SF9 cells were tested. The higher passage produced a lower viral titration. The size and time of appearance of the plaques was also different.

Susceptibility of BL6 nude (congenitally athymic) mice to Japanese encephalitis virus by the peripheral route

Studies on the susceptibility of adult BL6 nude (congenitally athymic, nu/nu) mice, their euthymic littermates (+/nu) and Swiss mice to Japanese encephalitis (JE) virus inoculated subcutaneously were carried out. The mice were observed over a period of 60 days p.i. for sickness and/or death, which was noticed only in nu/nu mice. However, the onset and the duration of sickness varied and no definite pattern was observed. Thirty four of 53 nu/nu, 28 of 42 +/nu and 30 of 52 Swiss mice bled during the first 5 days p.i. exhibited viraemia. Interestingly, only nu/nu mice had secondary viraemia during the period of sickness. The cause of sickness and death in nu/nu mice was confirmed by recovering the virus from the blood, the brain and other organs. Antibodies were detected in the sera of +/nu and Swiss mice from the 10th day p.i. onwards but not in nu/nu mice. These findings indicate the important role of functional T cells both in induction of active immunity and protection against JE virus infection in mice.

Two-way cross-protection between West Nile and Japanese encephalitis viruses in bonnet macaques

Cross-protection between Japanese encephalitis (JE) and West Nile (WN) viruses was tested in bonnet macaques (Macaca radiata) immunized either with JE virus (JEV) or WN virus (WNV). JEV immunized monkeys were challenged by intranasal (i.n.) route with WNV and vice versa. Four control unimmunized monkeys were similarly infected either with WNV or JEV. Two of three control monkeys infected with WNV, developed paralysis followed by death. Virus was recovered from the central nervous system (CNS) of the both dead control monkeys and the histopathological examination of CNS revealed changes suggestive of viral encephalitis. The control monkey infected with JEV developed encephalitis and the virus was recovered from the blood and CNS. All the 3 JEV-immunized monkeys withstood WNV challenge, whereas only 2 of the 5 WNV immunized monkeys withstood the challenge with JEV. Out of 3 WNV-immunized monkeys surviving challenge with JEV, 2 revealed symptoms suggestive of mild encephalitis followed by complete recovery. The third monkey died on the 60th day post-infection (p.i.) without any symptoms and virus was recovered only from the olfactory lobe. These studies indicate that the immunization with JEV protects the bonnet macaques against WNV, whereas the WNV immunization only reduces the severity of the disease due to JEV.

Serological studies on subacute sclerosing panencephalitis

This study reports the clinical picture and measles virus antibody titres in 32 patients with cases of suspected subacute sclerosing panencephalitis (SSPE). The history of myoclonic jerks, mental regression, inability to walk and slurred speech, were noted in these cases. The EEG showed generalised periodic complexes in twenty nine patients and only in three patients the EEG was not available. In all the above mentioned patients measles occurred at an early age (within a year).

Serological surveillance for HIV-l infection in Bombay

BACKGROUND

Screening of populations for the antibody to the human immunodeficiency virus has been recommended to be a practical method for assessing the prevalence of the infection and its potential for spread.

METHODS

Between 1987 and 1989 we carried out a serological survey for the detection of antibody to the human immunodeficiency virus type 1, using the enzyme linked immunosorbent assay, to screen 2123 persons belonging to different high-risk groups from various parts of Bombay.

RESULTS

Eighty-four repeatedly positive samples were subjected to the Western blot test for confirmation and 58 were found to be positive-4 (0.6%) out of 670 in 1987, 9(1.2%) out of 740 in 1988 and 45 (6.3%) out of 713 in 1989.

CONCLUSION

These data indicate that the human immunodeficiency virus type 1 infection has already spread in the cityof Bombay among the various high-risk groups and that its prevalence rose between 1987 and 1989.

Screening for AIDS in western India: transfusion aspects

Screening of blood donations for anti-HIV in western India has shown a rising trend of antibody-positive donors. There was a statistically significant difference between the proportion of positive reactors before 1986 and after 1986 (p less than 0.05).

Localization of arboviral antigen in brain tissues from patients with encephalitis

Brain tissues from 38 patients with a clinical suspicion of encephalitis or encephalopathy were examined by two immunoenzymatic techniques for the detection of arboviral antigen. Group B arboviral antigen was identified in 23 of these tissues. This simple method could be used for the diagnosis of the causal agent of encephalitis.

Tick-borne rickettsioses in Pune district, Maharashtra, India

An extensive study on tick-borne rickettsioses in the Pune district of Maharashtra revealed that Indian tick typhus exists as a zoonosis, which only occasionally causes disease in man. By sero-conversion in guinea pigs, presumptive isolates of Rickettsia conori and Coxiella burnetii were recovered from 4 of the 11 species of ticks examined. Boophilus microplus and Rhipicephalus haemaphysalis were found to be harbouring R. conori whereas C. burnetii was isolated from Haemaphysalis intermedia and Hyalomma hussaini in addition to the above mentioned 2 tick species. Complement fixation tests carried out on sera from various species of rodents and gerbils revealed the presence of antibodies against the R. conori antigen in the sera of Rattus blanfordi, R.r. rufescens and Suncus murinus. In the case of large mammals, similar antibodies were detected in the sera from dog, cow, horse and sheep. C. burnetii infection was found to exist in both the sylvan and domestic cycle, as evidenced from the involvement of ticks, large and small mammals and man in its natural history.

Fiberoptic endoscopy in the diagnosis of retained gastric antrum

Recurrent peptic ulcer following surgery has been extensively studied, but its causes are not always clear. Difficulties in the differential diagnosis of the various possible factors can be very puzzling, since most of the methods described fail to provide a reliable definitive diagnosis. In the present study the authors report on the results obtained with the use of fiberoptic endoscopy complemented by biopsy of the mucosa of the duodenal stump for the diagnosis of retained gastric antrum in recurrent ulcer following B-II type gastrectomy. Considering the good results obtained with this method in 20 out of 23 patients, with a high degree of accuracy in association with biopsy and without any complications, it is strongly recommended whenever there is a possibility that retained antrum is the cause of recurrent peptic ulcer.