Construction and validation of a multi-epitope in silico vaccine model for lymphatic filariasis by targeting Brugia malayi: a reverse vaccinology approach

BACKGROUND

Lymphatic filariasis (LF), often referred to as elephantiasis, has been identified as one of the 17 neglected tropical diseases by the World Health Organization. Currently, there are no vaccines available to treat this infection in humans. Therefore, with the objective of devising a novel preventive measure, we exploited an immunoinformatics approach to design a multi-epitope-based subunit vaccine for LF, that can elicit a variety of immune responses within the host. In this study, different B cell, T_C cell, and T_H cell-binding epitopes were screened from the antigenic proteins of Brugia malayi and they were passed through several immunological filters to determine the optimal epitopes.

RESULTS

As a result, 15 CD8+, 3 CD4+, and 3 B cell epitopes were found to be prominent, antigenic, non-toxic, immunogenic and non-allergenic. The presence of conformational B cell epitopes and cytokine-inducing epitopes confirmed the humoral and cell-mediated immune response that would be triggered by the constructed vaccine model. Following that, the selected epitopes and TLR-4-specific adjuvant were ligated by appropriate peptide linkers to finalize the vaccine construct. Protein-protein docking of the vaccine structure with the TLR4 receptor predicted strong binding affinity and hence putatively confirms its ability to elicit an immune response. Further, the efficiency of the vaccine candidate to provide a long-lasting protective immunity was assessed by in silico immune simulation. The reverse translated vaccine sequence was also virtually cloned in the pET28a (+) plasmid after the optimization of the gene sequence.

CONCLUSION

So taken together, by monitoring the overall in silico assessment, we hypothesize that our engineered peptide vaccine could be a viable prophylactic approach in the development of vaccines against the threat of human lymphatic filariasis.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1186/s42269-023-01013-0.

Wucherria bancrofti glutathione S-Transferase: Insights into the 2.3 Å resolution X-ray structure and function, a therapeutic target for human lymphatic filariasis

The notoriety of parasitic nematode survival is directly related to chronic pathogenicity, which is evident in human lymphatic filariasis. It is a disease of poverty which causes severe disability affecting more than 120 million people worldwide. These nematodes down-regulate host immune system through a myriad of strategies that includes secretion of antioxidant and detoxification enzymes like glutathione-S-transferases (GSTs). Earlier studies have shown Wuchereria bancrofti GST to be a potential therapeutic target. Parasite GSTs catalyse the conjugation of glutathione to xenobiotic and other endogenous electrophiles and are essential for their long-term survival in lymph tissues. Hence, the crystal structure of WbGST along with its cofactor GSH at 2.3 Å resolution was determined. Structural comparisons against host GST reveal distinct differences in the substrate binding sites. The parasite xenobiotic binding site is more substrate/solvent accessible. The structure also suggests the presence of putative non-catalytic binding sites that may permit sequestration of endogenous and exogenous ligands. The structure of WbGST also provides a case for the role of the π-cation interaction in stabilizing catalytic Tyr compared to stabilization interactions described for other GSTs. Hence, the obtained information regarding crucial differences in the active sites will support future design of parasite specific inhibitors. Further, the study also evaluates the inhibition of WbGST and its variants by antifilarial diethylcarbamazine through kinetic assays.

A study of help seeking behavior of psychiatric patients

Background: A large number of mentally ill patients prefer to visit non-medical practitioners such as faith healers becauseof the stigma attached to mental illness and/or belief that mental illness are caused by supernatural powers. Faith healersare more convenient to be approached fi rst because of ease of availability and prevalent cultural belief and persuasion.Objective: The current study aims to fi nd the help seeking behavior of patients suffering from mental illness and whomthey approach fi rst once affected, either psychiatrists or faith healers.Methods: A cross sectional study was conducted among patients admitted in the psychiatric ward of Kathmandu MedicalCollege Teaching Hospital during 1st January to 30th July 2012. All patients admitted in the ward during that period wereinformed about the purpose of the study and a written informed consent was taken. In case of psychotic patients, theconsent was obtained from nearby relatives.Results: Among 54 patients enrolled in the study, signifi cant number of psychotic patients (n=15) visited faith healersin comparison to only 4 non-psychotic patients. Number of females (n=12) visiting faith healers in comparison to males(n=7) was higher. Patients having belief in black magic were more likely to visit faith healers than those who were nonbelievers.In contrary to the popular belief, patients approaching the faith healers spent more money (>$20) in the treatment thanwho approached psychiatrists (<$20).Conclusion: The study shows that most of the patients suffering from mental illness prefer to approach faith healers fi rstbecause of the prevailing trust on faith healers, because they are locally available and because of a prevailing belief insupernatural causation of mental illness.DOI: http://dx.doi.org/10.3126/jkmc.v2i1.10538 Journal of Kathmandu Medical College, Vol. 2, No. 1, Issue 3, Jan.-Mar., 2013: 21-24

Depression in Elderly

DOI: http://dx.doi.org/10.3126/jpan.v1i1.9921 Journal of Psychiatrists' Association of Nepal Vol.1(1) 2011: 13-14

DNA vaccination with VP2 gene fragment confers protection against Infectious Bursal Disease Virus in chickens

Infectious Bursal Disease Virus (IBDV) causes immunosuppression in young chickens by destruction of antibody producing B cells in the Bursa of Fabricius and poses a potential threat to the poultry industry. We have examined the protective efficacy of a subunit DNA vaccine against IBDV infection in chickens in this study. An immunodominant VP2 gene fragment (VP252-417) was cloned into CMV promoter based DNA vaccine vector pVAX1 and in vitro expression of the DNA encoded antigens was confirmed by transfection of CHO cells with vaccine constructs followed by RT-PCR and western blot analysis using IBDV-antiserum. Two weeks old chickens were immunized intramuscularly with pVAXVP252-417 and the in vivo transcription of the plasmid DNA was confirmed by RT-PCR analysis of DNA injected muscle tissue at different intervals of post immunization. Tissue distribution analysis revealed that the plasmid DNA was extensively distributed in muscle, spleen, kidney, liver, and bursa tissues. Chickens immunized with pVAXVP252-417 developed high titer (1:12,000) of anti-VP252-417 antibodies. Further, chicken splenocytes from pVAXVP252-417 immunized group showed a significantly high proliferation to the whole viral and recombinant antigen (P<0.01) compared to control groups, which implies that pVAXVP252-417 codes for immunogenic fragment which has epitopes capable of eliciting both B and T cell responses. This is evident by the fact that, pVAXVP252-417 immunized chicken conferred 75% protection against virulent IBDV (vIBDV) challenge compared to the control group. Thus, the present study confirms that the immunodominant VP2 fragment can be used as a potential DNA vaccine against IBDV infection in chickens.

A study of depression among patients of substance use disorder

Background: Depressive disorder is frequently found as a comorbidity among patients with substance abuse. Most of the time it is reported as underdiagnosed and a majority of patients go untreated. Many studies have indicated that comorbid depressive symptoms play a major role in the prognosis of substance use disorder and the relapse has been found to be greater in patients who have a comorbid depression. The present study seeks to determine the comorbidity of depression in cases with substance abuse and their sociodemographic characteristics. Objective: The current study is aimed to determine the relationship between various drug abusing patterns and comorbidity of depression with substance use disorders. Methods: This was a cross-sectional study. The study was carried out in 42 patients, who were consecutively admitted in psychiatric ward of Kathmandu Medical College Teaching Hospital and Punarjeevan Hospital with the diagnosis of mental and behavioural disorder due to use of psychoactive substances, according to ICD-10. The study was carried out from 1st January 2010 to 30th December 2010. All patients were rated using Hamilton Depression Rating Scale. Results: Among all subjects, 31 (73.8 %) were found to be suffering from Depression among which 19 (45.2%) had mild to moderate depression and 12 (28.6%) had severe depression. Depression was seen among 80% of unemployed subjects, followed by 75% employed subjects and 68.8% students. In method of drug intake, 21 (50%) subjects used oral drugs, 12 (28.6%) subjects used intravenous route and 5 (11.9%) subjects used inhalational drugs. All patients using intravenous drugs were found to have depression. Among drugs abused, 22 (52.4%) patients used multiple substances like alcohol and cannabis, 11 (26.2%) patients used Heroin, 6 (14.3%) patients used drugs like Diazepam, Dextropropoxyphene, Nitrazepam and Promethazine, followed by 3 (7.1%) patients using Buprenorphine. Depression was found in 6 (54.54%) out of 11 subjects who used Heroin followed by 19 (86.63%) out of 22 subjects who were dependent on alcohol, cannabis and other substances. Conclusion: The result showed strong correlation between depressive symptoms and substance abuse, which draws attention to the need of taking into consideration the comorbidity and its management. Clinicians should routinely assess for depression in patients with substance abuse disorders. DOI: http://dx.doi.org/10.3126/jkmc.v1i2.8145 Journal of Kathmandu Medical College, Vol. 1, No. 2, Oct.-Dec., 2012: 96-99

Study of personality factors in attempted suicide

BACKGROUND

Suicidal attempt is becoming a major problem in the world, as it affects the person's career, life style, and family dynamics. Comorbid personality disorders are a risk factors for suicidal behavior. The aim of this study was to determine the various personality factors involved in attempted suicide.

METHODS

This is a descriptive study. This study was carried out in the patients, who attempted suicide, who were admitted in the wards of Kathmandu Medical College Teaching Hospital during 1st January 2010 to 30th July 2010. The 16-PF scale was used in all the subjects.

RESULTS

Total 46 cases were studied. Six (13%) subjects were seen as having "schizothymic" traits. Sixteen(34.8%) of the subjects were seen as having low intelligent traits. Total 14 (30.4%) were seen as having affected by feelings. Seven (15.2%)were seen as having humble traits. Fifteen (32.6%) were seen as having sober traits and there are no cases of happy-go-lucky. Three (6.5%) were seen as having expedient. Eight (17.4%) were seen as having shy traits and there are no cases seen of venturesome traits. Total 14 (30.4%) were seen as having tough-minded traits. Eight (17.4%) were seen as having suspicious personality traits while nine(19.6%) were seen as having practical personality traits. Ten (21.7%) were seen as having shrewd personality traits. Total 17 (37.0%) were seen as having apprehensive personality traits. Twelve (26.1%) were seen as having experimenting personality traits and 6 (13.0%) were seen having group dependent personality traits. Among the patients, 10 (21.7%) were seen having undisciplined personality traits. Seven (15.2%) were seen having relaxed personality traits. Total 12 (23.1%)were seen having extroversion traits. Six (13.0%) were seen having low anxiety traits. Ten (21.7%) were seen having tender-minded emotionality personality traits. Seven (15.2%) were seen having subduedness personality traits.

CONCLUSIONS

Our study highlights the importance of personality factors in attempted suicide and these factors are at risk in attempting suicide, therefore, which can be implemented in prevention of suicide.

A study of severity of intention of suicide in various psychiatric diagnoses

BACKGROUND

Suicidal intent has been described as the seriousness or intensity of the patient's wish to terminate his or her life. Suicide has become an important public health issue throughout the world. It is important to evaluate the intentions of suicide attempts and various psychiatric diagnostic perspectives to understand the multiple dimensions of suicide.

AIMS

The aim of the work was to study the severity of suicidal intention among suicide attempters in different psychiatric diagnoses and different mode of attempted suicide.

MATERIALS AND METHODS

This study was carried out in the patients, who attempted suicide, by various modes, who were admitted in the wards of KMCTH during 1st January 2007 to 30th December 2007. Suicide Intent Scale (SIS) was used in all the cases that had attempted suicide.

RESULTS

Total numbers of patients was 43. Mean SIS was 13.88. The results have shown that majority of cases were female 69.8% (n=30) and male were 30.2% (n=13). The commonest mode of suicide was poisoning 83.7% (n=36) in which moderate suicide intent was 58.3% (n=21); mild suicide intent 33.3% (n=12) and severe suicide intent 8.3% (n=3) (p value < .004). Pesticide (organophosphorus) ingestion was the commonest mode of suicide 44.4% (n=16), followed by pharmacological drugs 33.3% (n=12) (p value < 0.267). The commonest psychiatric diagnosis was depressive disorders 62.9% (n=27), in which moderate suicide intent was found to be maximum 70.4% (n=19) followed by mild suicide intent 14.8% (n=4) and severe suicide intent 14.8% (n=4) (p value < 0.002).

CONCLUSION

The increasing problem of pesticide poisoning and drug overdose demands strict legal scrutiny in the availability of common means of attempting suicide.

Experiencing stigma: Nepalese perspectives

BACKGROUND

Experiencing stigma by patients with mental illness in their day to day lives has substantial importance in treatment, compliance and quality of life. There is dearth of information and researches in experiences/ perceptions and coping of stigma in Nepal.

AIMS

The objective of this study was to find out experiences/ perceptions and coping of stigma and stigmatizations among patients with mental illness.

MATERIALS AND METHODS

This is a retrospective, cross sectional study of patients admitted in psychiatry ward. Patients were assessed using self-report questionnaire which focused on beliefs about discrimination against mental illness, rejection experiences, and ways of coping with stigma. Patient's socio demographic profiles were also assessed.

RESULTS

Fifty three patients completed questionnaire concerning various constructs of stigma. There were 29 male patients and 24 female patients. Majority (N=45; 84.9%) were of Hindu religion but there were mixed numbers regarding caste. Most of the patients were aware of the stigma associated with mental illness. There were experiences of rejection by family members and colleagues (N=23; 43.4%) and health care professional (N=16; 30.2%). There were strong perceptions of stigmatization felt by patients in different social circumstances. Though maintaining secrecy and avoidance/withdrawal of stigma provoking scenario were not experienced much, there was a strong sense of advocacy whenever there was any negative view of mental illness. Some of the questionnaire items in "perception", "rejection" and "coping" showed statistical significance (p=0.001).

CONCLUSION

People with mental illness experience stigma during their course of illness and treatment and it is an important determinant for the relapse of symptoms and non-compliance to treatment. Despite experiencing stigma, patients were generally treated fairly by other people. Patients develop various mechanisms to cope with stigma, mostly secrecy and avoidance. Advocacy and anti-stigma campaign along with positive attitudes of health professionals play important role in decreasing stigmatizing experiences in patients.

Rare codon priority and its position specificity at the 5' of the gene modulates heterologous protein expression in Escherichia coli

Rare codons and their effects in heterologous protein expression in Escherichia coli were addressed by many investigators. Here, we propose that not all rare codons of a foreign gene have negative effect but selective codon among them and its specific position in the downstream of the start codon modulates the expression. In our study, streptokinase (47 kDa), encoded by skc gene of Streptococcus equisimilis was expressed in E.coli. The analysis of relative codon frequency of skc gene in E.coli reveals the presence of 30% of rare codons in it. Nevertheless, E.coli managed to yield over-expression of this target protein. To explore the codon bias in expression, we have introduced the selective AGG codon at different positions of skc gene such as +2,+3,+5,+8,+9 and +11. The results revealed that at +2 position "AGG" aided over-expression while shifting to +3 and +5 positions it rendered nil expression. In contrary, shifting of AGG codon to later positions like +9 and +11 the inhibitory effect was reversed and resulted in over-expression. The effect of 'AGG' rare codon was further studied in GFP expression. In conclusion, besides the choice of rare codons, their precise positions in the foreign gene dictate the level of protein expression.

Modified Welsh regimen: a promising therapy for actinomycetoma

BACKGROUND

Mycetoma has a worldwide geographical distribution which is extremely uneven; however, it is a common disease in India and responsible for causing significant morbidity. Treatment of this condition is often a challenge for the treating dermatologist. The authors report a promising therapy for patients of actinomycotic mycetoma.

METHODS

This assessment series included 18 patients with a confirmed diagnosis of actinomycetoma, and who had shown a poor response to previous treatments. Patient received a combination therapy of the Welsh regimen (amikacin along with cotrimoxazole) to which rifampicin was added as a third drug. Clinical evaluation included radiology and laboratory investigations.

RESULTS

Sixteen patients out of 18 completed the combination therapy, which lead to remission. Two patients were lost to follow-up. Of the 16 patients in remission, no recurrence was observed during a follow-up period of up to 18 months.

Diagnostic variability and therapeutic efficacy of ECT in Nepalese sample

BACKGROUND

Though electroconvulsive therapy (ECT) has been used in Nepal for last twenty years, researches regarding its use, its efficacy and other data are non-existent.

AIMS

The objective of this study was to know about diagnostic variability and therapeutic efficacy of the use of ECT in hospitalized patients.

METHODS

This is a prospective comparative study between patients who received ECT and who did not using ICD-10 as diagnostic confirmation. Psychopathology was evaluated using Brief Psychiatric Research Scale (BPRS), Hamilton Depression Rating Scale (HAM-D) and Young Mania Rating Scale (YMRS) between the groups at admission, at discharge, at 1st month, at 6th month and at 12th month. Functional assessment of patients was done using Global Assessment of Function (GAF). Modified ECT was performed using general anaesthetic agent.

RESULTS

47 patients received ECT as compared to 78 patients who were non-receivers. The patients with most common five diagnosis were paranoid schizophrenia (14.4%); psychotic depression (13.6%) ; undifferentiated schizophrenia (8.8%) ; bipolar mania (7.2% ) ;severe depression without psychosis (5.6%) . There was significant decrease in BPRS in ECT receiver as compared to non-receivers at discharge (p=0.0001), 1st month (p=0.0001), 6th month (p=0.0001) and 12th month (p=0.0001) ; in YMRS at discharge (p=.008), 1st month (p=.002) and at 12th month (p=.015) ; in HAMD-M at discharge (p=0.0001), at 1st month (p=0.0001), at 6th month (p=0.0001) and at 12th month (p=0.0001) ; in GAF at discharge (p=0.0001), at 6th month (p=0.0001) and at 12th month (p=0.0001).

CONCLUSION

There was significant improvement in overall psychopathology of patients who received ECT as compared to non-receivers. The improvement was shown by decrement in scores in BPRS, YMRS, HDRS and GAF at the time of discharge, 1st month, 6th month and 12th month which were statistically significant. Day to day functional status of patients also improved as shown by GAF. The efficacy of ECT was very significantly shown in this study with all the psychiatric spectrum disorders.

Comparative study of esmolol and labetalol to attenuate haemodynamic responses after electroconvulsive therapy

OBJECTIVE

The study was designed to evaluate the hemodynamic effects of Esmolol and labetalol in patients undergoing electroconvulsive therapy.

MATERIALS AND METHODS

Ninety patients undergoing electroconvulsive therapy treatment were studied according to randomized, double blind placebo controlled protocol. Ninety patients were divided into three groups with thirty patients in each group. Patients received either Esmolol (1 mg/kg), Labetalol (0.25 mg/kg) or Normal Saline (placebo) intravenously just after induction with propofol. The baseline heart rate and blood pressure were recorded. Hemodynamic parameters before and after drug therapy and after the ECT current application, were recorded at different time intervals.

RESULTS

It was found that Esmolol significantly attenuated the degree of tachycardia and hypertension after ECT in comparison with placebo in the first three minutes (p<0.05), whereas the rise in HR and blood pressure was significantly blunted in the labetalol group in comparison to placebo, from three minutes onward till ten minutes. (p<0.05).

CONCLUSION

It was concluded that Esmolol is effective in blunting the hemodynamic response after ECT stimulus in the first three minutes after application of the electrical current, whereas Labetalol is effective after five minutes onwards till ten minutes.

Encephalocraniocutaneous lipomatosis: a rare neurocutaneous syndrome

Encephalocraniocutaneous lipomatosis is a congenital hamartomatous disorder with unique ocular, cutaneous and neurological features. A 13-year-old boy presented with history of mental retardation and delayed developmental milestones. Bulbar conjunctiva of left eye showed hypertrophy with a soft reddish limbal nodule encroaching on the cornea. Dermatological examination showed multiple patches of alopecia, soft papules in the left perioral and periorbital areas, soft masses over the right axilla, trunk and in the lumbosacral region suggestive of lipomas. The CT scan of the brain revealed well-defined, hypodense lesions in both the cerebellar hemispheres suggestive of lipomas. The constellation of these findings led us to a diagnosis of encephalocraniocutaneous lipomatosis.

Nepal mental health country profile

The Kingdom of Nepal is situated in the heart of Asia, between its two big neighbours China and India. Nepal is home to several ethnic groups. The majority of the 23 million population reside in the countryside. Although figures on many of the health and socio-economic indicators are non-existing, some existing ones show gradual improvement over the years. However the figures for illiteracy and infant mortality are still one of the highest in the world. As per GDP, and population living below the poverty line and per capita income, Nepal still remains one of the poorest countries in the world. Despite this, it provides shelter to thousands of Bhutanese refugees in its land. Frequent natural disasters and recent violent conflicts in Nepal have further added hardship to life. Less than 3% of the national budget is allocated to the health sector. Mental health receives insignificant attention. The Government spends about 1% of the health budget on mental health. There is no mental health act and the National Mental Health Policy formulated in 1997 is yet to be fully operational. Mental ill health is not much talked about because of the stigma attached. The roles of the legal and insurance systems are almost negligible. The financial burden rests upon the family. The traditional/religious healing methods still remain actively practiced, specifically in the field of mental health. The service, comprising little more than two-dozen psychiatrists along with a few psychiatric nurses and clinical psychologists (mainly practicing in modern health care facilities) has started showing its impact--however this is limited to specific urban areas. The majority of the modern health care facilities across the country are devoid of a mental health facility. The main contextual challenges for mental health in Nepal are the provision of adequate manpower, spreading the services across the country, increasing public awareness and formulating and implementing an adequate policy.

A study of the first 350 cases referred for EEG in Kathmandu Medical College Teaching Hospital

Electroencephalography or EEG is a neurological test that uses an electronic monitoring device to measure and record electrical activity in the brain. Epilepsy is defined as a recurrent tendency to unprovoked seizure. About 0.5% to 2% of the population has epilepsy.

MATERIAL AND METHODS

This is a retrospective study of the first 350 odd cases referred for EEG at Kathmandu Medical College Teaching Hospital, Kathmandu during period November 2002- September 2002 (Mangsir 2058- Bhadra 2059).

RESULTS

Most patients fall in the age group of 11-20 years and more than 50% referred cases fall in the prime of life, i.e., 11-30) years. 16% of patients with the history of seizure did not use any AED and 32% who though had no history of seizures were actually using AED. It is seen that out of 149 reported normal, 57 (38%) had history of seizure; but out of 208 reported abnormal in EEG only 92 (42%) had history of seizure.

DISCUSSION

EEG is not a very sensitive or a specific tool; however, in our study it was seen to be more sensitive than specific. It is till very useful in classifying seizure types, in locating epileptic focus prior to surgery or in some confusing situation when movement disorder may simulate seizure disorder or vice versa.

CONCLUSION

Although EEG is not a very sensitive or specific investigation, it is more sensitive than specific.

PROFILE OF FIRST 100 IN-PATIENTS IN DE-ADDICTION WARD T.U. TEACHING HOSPITAL, NEPAL

ABSTRACTMen and women suffering from the problems of various psychoactive substance abuse were helped to comeout of the problem by the Department of Psychiatry and Mental Health since it’s establishment in 1986.Since the De-addiction ward started functioning under the Department of Psychiatry and Mental Health,T.U. Teaching Hospital (TUTH) from February, 2000 A.D., people suffering from various drugs relatedproblems have received in-patient care. This study describes the profile of first 100 psychoactive substanceabusers admitted in this ward. The first hundred patients were admitted in a period of 5 months and 2weeks, in an average of 18 patients per month. Eighty eight males, the average age being 33.3+10.98 years.Seventy were married. The average years of education was 8.56+4.94 years. Alcohol (n=58) was the commonestinitial substance, followed by cannabis (n=19) and cigarette (n=11). Currently 60 were predominantly alcoholusers and 36 predominantly opiate users. The majority were multiple substance users: 79 used alcohol, 37used opiates, 25 used cannabis and 18 used benzodiazepines. Age at first use was 19.57+5.54 years andduration of continuous use was 5.88+4.47 years. Eleven (8 males) were HIV ELISA reactive, all of whomwere parenteral opiate abusers. Thirty-nine (35 males) had fatty changes in liver and 6 (all males) hadcirrhotic changes in liver. Those 45 persons with liver abnormality were all alcohol users.Key Words: psychoactive substance, alcohol, opiates, HIV, liver changes.

Glycaemic index of conventional carbohydrate meals

The glycaemic index (GI) and the triacylglycerol response were measured in thirty non-insulin-dependent diabetes mellitus patients given 50 g portions of five different conventional Indian meals containing semolina (Triticum aestivum) cooked by two different methods, or combinations of semolina and pulse (black gram dhal (Phaseolus mungo), green gram dhal (Phaseolus aureus) or Bengal gram dhal (Cicer arietum)). There were no significant differences among meals in mean GI except for meals based on roasted semolina or semolina-black gram dhal. Compared with the blood glucose response for a 50 g glucose load, only meals based on steam-cooked semolina and semolina-Bengal gram dhal elicited a significantly lower response at 1 h postprandially, and only meals based on semolina-black gram dhal at 2 h postprandially. No significant differences were found among the meals in the triacylglycerol-response.

Behavioral effects of ethanol inhalation in rats

Behavioral effects of ethanol inhalation were studied on two fixed-ratio (FR) liquid-reinforced schedules and a continuous reinforcement (CRF) schedule intracranial self-stimulation (SS) in rats using the inhalational behavioral chamber designed in our laboratory. In the FR-24 schedule ethanol caused a decrease of reinforcement rate at 161 ppm and higher concentrations. In the FR-50 schedule decreases of the rate were observed at 102 ppm and 203 ppm. In the SS behavior ethanol produced a decrease in the rate of reinforcement at 603 ppm and higher concentrations. In rats of this schedule, blood ethanol concentrations were measured to be 393 micrograms/ml and 545 micrograms/ml after exposure to 600 ppm and 1200 ppm of ethanol respectively. Acute tolerance to ethanol was observed in these experiments, particularly in the FR-24 schedule. Thus ethanol inhalation could produce adequate blood concentrations so as to produce behavioral effects.

Effects of ethanol inhalation on EEG in rats

Effects of ethanol on duration of stages of sleep-wake cycle and EEG power spectra were measured during a 2-h exposure in a dynamic inhalational chamber in rats. Rats were exposed to one of four graded concentrations (approx. 100, 400, 800 and 1600 ppm) of ethanol on different days. Ethanol was found to increase the duration of waking (W) with a decrease in duration of rapid eye movement (REM) sleep at 100 and 400 ppm. No effect was observed at 800 and 1600 ppm on the stages of sleep-wake cycle or at 100-1600 ppm on EEG power spectra from the somatosensory or visual cortices. Results indicate that ethanol administered by inhalation could produce arousal action at low doses, but did not have any effect on EEG power spectrum at the concentrations used.

Glycemic index of traditional Indian carbohydrate foods

The glycemic index (GI) was determined in 36 non-insulin-dependent diabetes mellitus patients who were fed 50 g carbohydrate portions of six Indian conventional foods, including rice, a combination of rice-legume (Bengalgram, peas, and greengram), and a combination of rice-dal (greengram dal and redgram dal -- dal is dehusked and split legume). In addition to the GI, triglyceride (TG) responses of these foods were also determined. A higher GI was obtained for rice and for rice with peas; all other combinations yielded lower glycemic indices. However, all the foods produced significantly lower blood glucose response 2 hours postprandially as compared with blood glucose responses to a 50 g glucose load for the same group. No significant difference was observed for TG responses to the different foods.

Sensitivity of EEG in young rats to toluene exposure

Effects of toluene on the electroencephalogram (EEG) and its power spectra were measured during a 2-hr exposure in a dynamic inhalational chamber in young rats (30-53 days old) and compared to those in adult rats (63-77 days old). Rats were exposed to one of the three concentrations [low (108-111 ppm), medium (160-163 ppm), and high (407-432 ppm)] of toluene on different days. In tests on sleep-wake cycle, in the young animals the duration of the wake stage (W) was increased with decreases of rapid eye movement (REM) and non-REM (NREM) sleep during hr 1 and hr 2 of exposure to the low concentration. These effects were marked at the medium and the high concentrations. In adult rats, at the low concentration the increase of W and the decrease of REM were observed only at hr 1; however, at medium and high concentrations these changes of W and REM sleep were marked along with a decrease of NREM. Comparison of the changes of duration of different states in rats of two age groups showed that there was a significant difference in the increase of W and the decrease of NREM sleep in young rats at hr 2 of exposure to low concentrations only compared to those in adult rats. Tested on power spectrum in young rats during REM sleep recorded from the visual cortex, the power of delta waves increased at the medium and high concentrations and that of theta wave decreased at the high concentration during hr 2 of exposure compared to the controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of toluene exposure on the spontaneous cortical activity in rats

Effects of toluene on the electroencephalogram (EEG) and its power spectra were measured during a 2-hr exposure in a dynamic inhalational chamber in rats. Rats were exposed to one of six graded concentrations (110.6, 162.5, 432, 676, 1558, 2730 ppm) of toluene on different days. It was found that the duration of waking (W) was increased with a decrease in duration of rapid eye movement (REM) sleep even at 110.6 ppm. Duration of nonrapid eye movement (NREM) sleep was decreased with an increase of W and a decrease of REM sleep at 162.5 ppm. Dose-related effects were noted in higher concentrations. The power of delta frequency band was increased with a decrease of theta frequency band power at hr 1 of exposure to 676 ppm during REM sleep recorded from the visual cortex. The power of theta frequency band was also decreased at hr 2 of exposure at 432 ppm. During W and NREM sleep power spectra were not changed significantly. Results indicate that the changes of EEG are a sensitive measure of the effects of toluene on the central nervous system (CNS).

Rebound increase of basal cAMP level in NG108-15 cells during chronic morphine treatment: effects of naloxone and chloramphenicol

The effects of morphine on the basal cAMP level in the neuroblastoma X glioma NG108-15 hybrid cell line have been studied. Morphine (10 microM) added to the incubation media at hr 0 caused a rapid and significant decrease in the cAMP level up to hr 1; the level then slowly returned to the control at hr 6, and gradually increased to its peak at hr 36, returning to the control at hr 60. These results provide the first evidence for a delayed rebound increase of cAMP during morphine treatment. Naloxone (10 microM) added at hr 0 concomitantly with morphine blocked the morphine-induced decrease in cAMP level at hr 1 and attenuated its increase at hr 36. However, when naloxone was added at hr 5.5, the cAMP level significantly increased at hr 6, and at hr 36 the cAMP level increase was the same as in the case of morphine alone. Furthermore when naloxone was added 0.5 hr prior to harvesting the cells at hr 6, 12, 24 and 36, the cAMP level showed an immediate increase at each time point up to about the same level as observed with morphine alone at hr 36. Chloramphenicol, a protein synthesis inhibitor (100 microM) itself caused little or no change in the cAMP level. Added 30 min before morphine, chloramphenicol decreased the morphine-induced rebound increase at hr 36 in a concentration-dependent manner without any significant effect on cAMP decrease at hr 1. However when chloramphenicol was added at hr 5.5, the morphine-induced rebound increase at hr 36 was also attenuated, thereby suggesting an involvement of macromolecular synthesis in the rebound increase of cAMP which may be used as a model for the development of morphine dependence.

Effect of morphine on self-stimulation in rats and its modification by chloramphenicol

The effect of morphine was studied on self-stimulation (SS) behavior in rats implanted with bipolar electrodes in the posterior hypothalamus. A single dose (10 mg/kg) of morphine decreased SS responding within 10-20 min, reaching a minimum level between 20-40 min after which the responding gradually returned to normal. The SS responding then increased above the control level at 120-180 min postdrug, then slowly returned to normal, thus showing a rebound effect. The combination treatment with morphine (10 mg/kg) and chloramphenicol (50 mg/kg) on SS behavior produced an accentuation of the initial decrease in responding, which was prolonged before gradually returning to the control levels without showing any rebound effect. The data suggest that alterations in protein synthesis may underlie the suppressed excitatory effect of a high dose of morphine on SS behavior.

Effect of inhalation of xylene on intracranial self-stimulation behavior in rat

The effect of the inhalation of xylene on intracranial self-stimulation behavior was studied in rats in a flow-through (dynamic) inhalational behavioral chamber. Rats were exposed successively to four graded concentrations (102, 192, 419 and 623 ppm) of xylene vapor during 2-hr sessions on different days. The rate of lever-pressing showed a dose-dependent decrease during exposure to 192, 419 and 623 ppm of xylene. The 4-hr exposure to the smallest concentration (106 ppm) of xylene failed to show any effect on self-stimulation behavior. During a 5-day 2 hr/day exposure, the decrease in response observed on the 1st day was further accentuated with a nadir on the 3rd day; from the 4th day onwards, the depressant effect was attenuated showing the development of tolerance.

Effect of xylene inhalation on fixed-ratio responding in rats

The effect of xylene inhalation was studied on operant behavior under a fixed-ratio (FR24) schedule in rats. Experiments were performed while rats were being exposed to xylene vapor in an inhalational (flow-through) behavioral chamber. Rats were exposed successively to three graded concentrations (113, 216 and 430 ppm) of xylene vapor each for 2 hr in range-finding studies during 6 1/4-hr sessions. The reinforcement rate which is correlated with FR responding was shown to be decreased at hr 1, hr 3 and hr 5. However at hr 2, hr 4 and hr 6 the reinforcement rate in rats increased approaching the control levels, thereby indicating development of tolerance. When rats were exposed to one of the three graded concentrations of xylene for 2 hr on separate days, they also showed a decrease in the reinforcement rate at hr 1; development of acute tolerance was also noted in this schedule. Exposure to the lowest (98.5 ppm) level of xylene used during 5-hr sessions caused no significant decrease in the reinforcement rate. This study thus attempts to identify a minimum effective concentration of xylene and indicates the development of acute tolerance to behavioral effect of xylene.

An inhalational behavioral chamber

An inhalational (flow-through) behavioral chamber has been designed and prepared in order to facilitate recording of the behavioral performance of a small experimental animal (e.g., rat and mouse) while the subject is being exposed to an inhalant (vapor or gas). The animal can be clearly viewed during behavioral performance inside the chamber, which consists of a cylindrical glass jar. The apparatus is made up of easily available materials (e.g., glass, metal, Teflon, etc.) that are not affected by usual industrial solvents. At the present stage of its development, three types of behavioral schedules can be performed within the chamber: schedules involving brain stimulation (e.g., self-stimulation, avoidance of aversive stimulations); liquid-reinforced schedules (e.g., fixed ratio, fixed interval, variable ratio, variable interval, differential reinforcement of low rates); shock avoidance (classical or continuous). The schedules can be microcomputer assisted. The device is suitable for study of behavioral pharmacology and toxicology of inhalants.

Long-term desipramine treatment attenuates clonidine-induced suppression of ventral tegmental self-stimulation

Long-term administration of the tricyclic antidepressant desipramine did not change the rate of self-stimulation responding in the A10 (ventral tegmental) area but significantly attenuated the suppressive effect of the selective alpha 2-adrenergic agonist clonidine on this behavior. These findings demonstrate an involvement of noradrenergic mechanisms in the regulation of ventral tegmental self-stimulation and further suggest that adaptive changes in inhibitory presynaptic noradrenergic receptors may be involved in desipramine's antidepressant effects.

Phencyclidine (PCP): some human studies

Studies on the effects of PCP have been conducted in volunteers in the Army Laboratories and elsewhere and in illicit users. The present review has summarized the observations of many investigators which showed that the acute effects of PCP following several routes of administration were shown to be dose-related. High doses of PCP produce disturbing manifestations including psychosis, numbness, light-headedness, vertigo, ataxia, and nystagmus due to acute intoxication. Furthermore, some subjects became irritable, argumentative or negative under the conditions of social stress and demanding tasks. In addition to a variety of central action, PCP has also been shown to affect cardiovascular function, heat storage, and exercise performance. PCP can also induce, although rarely, prolonged toxic psychosis in chronic abusers and precipitate psychotic episodes in psychotic and prepsychotic personalities. Tolerance, but not physical dependence, develops to the effects of PCP. Psychologic dependence as indicated by craving for the drug has however been reported.

Pharmacology of some synthetic tetrahydrocannabinols

DMHP (1-hydroxy-3-1', 2'-dimethylheptyl-6,6,9-trimethyl 7,8,9,10-tetrahydro-6-dibenzopyran or in brief dimethyl heptyl pyran, EA 1476) is a synthetic analog of delta 9-tetrahydrocannabinol (delta 9-THC). Both DMHP and its acetate, DMHPA (EA 2233) produce varying degrees of physical and mental incapacitation. Both compounds elicit orthostatic hypotension at dose levels far below those required to produce mild mental incapacitation. Compared with delta 9-THC, DMHP has clearly more potent and prolonged hypotensive action, but much less psychological effect. The potencies of DMHP and DMHPA are more or less similar, but the acetate derivative is more stable against the degrading effects of light and air. Like DMHP, DMHPA consists of eight isomers which vary in their potency. Accordingly, depending on the proportion of the isomers, the racemic mixtures show variability in their potencies. The isomers 2 and 4 have been shown to be more potent than the other isomers.

Self-stimulation responses are altered following long-term but not short-term treatment with clorgyline

Clorgyline (a selective monoamine oxidase-inhibiting antidepressant) given chronically facilitated hypothalamic self-stimulation in rats, while acute treatment was without effect. Furthermore, long-term but not short-term clorgyline treatment significantly attenuated the suppressive effect of the selective alpha 2-adrenergic agonist clonidine on this behavior. These findings suggest that adaptative alterations in the modulation of rewarded behavior by inhibitory presynaptic noradrenergic receptors may be involved in antidepressant efficacy.

Behavioral and neurochemical effects of hydergine in rats

Effects of various (20, 40 or 80 mg/kg; intragastric instillation) doses of Hydergine (dihydroergotoxine) were studied on the self-stimulation (SS) behavior (in young and old rats with electrodes implanted in the A10 area) and also on spontaneous motor activity (SMA) and stereotypy (ST) as well as on the concentrations of norepinephrine (NE), dopamine (DA), serotonin (5-HT) and gamma-aminobutyric acid (GABA) in discrete brain areas, such as caudate nucleus (CN), pons-medulla (PM) and diencephalon-midbrain (DM) in adult rats. Following Hydergine administration, SS and SMA showed a dose-dependent increase with peak effects occurring between 80-120 min and then decreased. ST was not induced at any dose. DA and NE levels in the DM also showed a dose-dependent increase at 90 min and then sharply decreased up to 120 min after drug administration. NE in the PM and DA in the CN showed a similar pattern, but to a smaller degree. GABA in the DM and CN showed marked increases up to 120 min, while 5-HT in the PM and DM showed steady declines during the same period. Thus it appears that the behavioral stimulant effects of Hydergine may be correlated to increase in NE and DA levels, particularly in the DM.

Inhibition of behavioral effects of cocaine by actinomycin D in rats

Interactions of actinomycin D (AD, 25 micrograms--50 micrograms/kg intraperitoneally, i.p., or 1 microgram intracerebroventricularly, i.c.v.) with repeated cocaine administration (15 mg/kg i.p. twice daily at 8-hr intervals) were investigated on the spontaneous motor activity (SMA) and stereotypy (ST) in rats. Following repeated injections of cocaine in combination with saline (i.p. or i.c.v.), both SMA and ST were gradually increased to their peaks on day 9, then decreased up to the day 19 and thereafter maintained at higher than normal levels. Given along with cocaine or saline, AD (i.p. or i.c.v.) caused gradual and significant decreases of SMA and ST. On stopping AD (i.p. on day 5 and i.c.v. on day 9) injection, both SMA and ST increased again. After stopping its i.c.v. injection both behaviors were increased to their peaks on day 10, then gradually decreased to and maintained at slightly higher than normal levels on day 18 onwards. The possible mechanisms of actions of AD as an inhibitor of cocaine-induced behavioral effects have been discussed.

Electrophysiological correlates of the behavioral effects of tubocurarine in conscious cats

The effects of tubocurarine on behavior, electrical activity, and auditory evoked potentials were studied in restrained conscious cats. Tubocurarine hydrochloride (doses of 0.05--1 micrograms intraventricularly) produced various central stimulatory effects characterized by EEG desynchronization, decrease in both low (7--9 Hz) and high (10--14 Hz) alpha waves, and decrease in the amplitude and area of the surface positive (P1) wave of auditory evoked potentials. Concomitant with the alterations in brain electrical activity tubocurarine hydrochloride produced generalized behavioral arousal phenomena and the cats became restless and exhibited miaowing and increased movement of the head and ears. Almost all parameters except behavior showed a distinct dose-response relationship. A correlation between the behavioral effects and the EEG analog was thus demonstrated.

Actions and interactions of amphetamine on self-stimulation in rats

The dose-response relationship for d-amphetamine (0.125-2 mg/kg, IP) and its l-isomer (0.125-3 mg/kg, IP) was studied in self-stimulation behavior of rats each with an electrode at posterior hypothalamus (PH, mainly monoaminergic) or area ventralis tegmentum (A10, dopaminergic). The drug effects increased with the dose reaching a peak (at 0.5 mg/kg with d-amphetamine and at 1.0 mg/kg with 1-amphetamine) and then decreased. The d-isomer was approximately twice as potent as the l-isomer in enhancing intracranial self-stimulation (ICSS) rate with electrodes at either site. Azaperone (mainly an alpha-adrenergic blocker) and haloperidol (an antidopaminergic neuroleptic) used in small doses (0.05 and 0.008 mg/kg respectively) which did not affect the baseline responding, blocked amphetamine-induced enhancement of ICSS in both groups of rats. Thus, amphetamine-induced facilitation of ICSS at both PH and A10 areas and its blockade by an alpha-adrenergic blocker as well as an antidopaminergic neuroleptic show the involvement of both noradrenergic and dopaminergic mechanisms in self-stimulation behavior.

Interactions between motor activity and sterotypy in cocaine-treated rats

Effect of a single administration of a dose (5, 10, or 15 mg/kg, i.p.) of cocaine hydrochloride on spontaneous motor activity (SMA) and stereotypy (ST), and interactions between these behaviors were investigated in rats. SMA showed peak increases within 10 min and at 120 min after cocaine injection. Drug-induced stereotypy was maximal during the interval between these two peaks in SMA. Several neurotransmitters may be involved in the interactions between SMA and ST.

Actions and interactions of cocaine on self-stimulation behavior in rats

The effect of cocaine, over a dose range of 2--60 mg/kg, i.p., on self-stimulation (SS) behavior was studied in rats with electrodes either in the posterior hypothalamus (PH, monoaminergic) or the area ventralis tegmentum (A10, dopaminergic). The drug increased SS behavior with peak effects at 30 mg/kg in PH rats and 20 mg/kg in A10 rats. Azaperone (an alpha-adrenergic blocker) and haloperidol (an antidopaminergic neuroleptic) given at doses that did not affect baseline SS responses reduced cocaine-induced enhancement of SS in both PH and A10 rats, showing the involvement of both noradrenergic and dopaminergic mechanisms in SS behavior. A scopolamine dose that itself facilitated SS responding enhanced the effect of cocaine on this behavior, thus suggesting an additional involvement of cholinergic mechanisms in cocaine effect.

Modification of behavioral and neurochemical effects of cocaine by haloperidol

Cocaine (20 mg/kg, i.p.) stimulated spontaneous motor activity (SMA) and induced stereotypy (ST) in rats. Haloperidol at 0.015 mg/kg, i.p. dose reduced or blocked cocaine-induced ST, but did not affect, drug-induced hyperactivity. At 0.03 mg/kg, i.p. dose of haloperidol, both behavioral effects were blocked. Cocaine decreased the norepinephrine (NE) and serotonin (5-HT) contents of diencephalon-midbrain (DM) and pons-medulla (PM) and increased dopamine (DA) contents in the DM and caudate nucleus (CN) at 20 min after its administration. Haloperidol (0.03 or 0.015 mg/kg) at 30 min postdrug produced opposite effects on the levels of NE, DA and 5-HT in the respective brain areas compared to cocaine. Given in combination, haloperidol reversed the effects of cocaine on the levels of NE, DA and 5-HT. Thus the cocaine-induced behavioral changes and their modification by haloperidol can be correlated to the neurochemical changes produced by these drugs alone or their combination.