Hyperbaric oxygen therapy effectively alleviates D-galactose-induced-age-related cardiac dysfunction via attenuating mitochondrial dysfunction in pre-diabetic rats

Currently, the prevalence of obesity in aging populations is fast growing worldwide. Aging induced by D-galactose (D-gal) is proven to cause the worsening of cardiac dysfunction in pre-diabetic rats via deteriorating cardiac mitochondrial function. Hyperbaric oxygen therapy (HBOT) has been shown to attenuate D-gal-induced cognitive deterioration through decreased inflammation and apoptosis. We tested the hypothesis that HBOT alleviates D-gal induced cardiac dysfunction via improving mitochondrial function in pre-diabetic rats. Wistar rats (n=56) were fed normal diet or high-fat diet for 12 weeks. For subsequent 8 weeks, they were subcutaneously injected either vehicle (0.9% normal saline) or D-gal (150mg/kg/day). Rats were randomly subdivided into 7 groups at week 21: sham-treated (normal diet fed rats with vehicle (NDV), high-fat diet fed rats with vehicle (HFV), normal diet fed rats with D-gal (NDDg), high-fat diet fed rats with D-gal (HFDg)) and HBOT-treated (HFV, NDDg, HFDg). Sham rats received ambient pressure of oxygen while HBOT-treated ones received 100% oxygen given once daily for 60 minutes at 2 atmosphere absolute. HBOT reduced metabolic impairments, mitochondrial dysfunction and increased autophagy, resulting in an improvement of cardiac function in aged pre-diabetic rats.

Hyperbaric oxygen therapy restores cognitive function and hippocampal pathologies in both aging and aging-obese rats

The population of obese-elderly has increased prominently around the world. Both aging and obesity are major factors of neurodegeneration. The present study hypothesizes that HBOT attenuates metabolic disturbance, cognitive decline, hippocampal pathologies in aging and aging-obese model. Sixty Wistar rats were separated into 2 groups to receive normal-diet (ND) or high-fat diet (HFD) for 22 weeks. At week 13, ND rats were divided into two subgroups to receive vehicle (0.9 % NSS, s.c) or d-gal (150 mg/kg/d, s.c) for total 10 weeks. HFD rats were injected only d-gal (150 mg/kg/d, s.c; HFDD) for total 10 weeks. At week 20, rats in each subgroup were given sham-treatment (1ATA, 80 L/min, 80 min/day), or HBOT (2ATA, pure O₂, 250 L/min, 80 min/day) for 14 days. Novel object location test, metabolic parameters, and hippocampal pathologies were determined after HBOT. d-gal induced insulin resistance, increased oxidative stress, autophagy impairment, microglial hyperactivation, apoptosis, synaptic dysplasticity which resulted in cognitive impairment. d-gal-treated HFD-fed rats had the highest levels of oxidative stress, apoptosis, dendritic spine loss. HBOT attenuated insulin resistance, cognitive impairment, hippocampal aging and pathologies in both models. These findings suggest that HBOT restored insulin sensitivity, hippocampal functions, cognition in aging and aging-obese models.

Hyperbaric oxygen therapy attenuates D-galactose-induced-age-related cardiac dysfunction through mitigating cardiac mitochondrial dysfunction in pre-diabetic rats

Background

D-galactose (D-gal) induced ageing has been shown to exacerbate left ventricular (LV) dysfunction via worsening of apoptosis and mitochondrial dysfunction in the heart of obese rats. Hyperbaric oxygen therapy (HBOT) has been demonstrated to exert anti-inflammatory and anti-apoptotic effects in multiple neurological disorders. However, the cardioprotective effect of HBOT on inflammation, apoptosis, LV and mitochondrial functions in D-gal induced ageing rats in the presence of obese-insulin resistant condition has never been investigated.

Purpose

We sought to determine the effect of HBOT on inflammation, apoptosis, mitochondrial functions and LV function in pre-diabetic rats with D-gal induced ageing. We hypothesized that HBOT attenuates D-gal induced cardiac mitochondrial dysfunctions and reduces inflammation and apoptosis, leading to improved LV function in pre-diabetic rats.

Methods

Forty-eight male Wistar rats were fed with either normal diet or high-fat diet for 12 weeks. Then, rats were treated with either vehicle groups (0.9% NSS, subcutaneous injection (SC)) or D-gal groups (150 mg/kg/day, SC) for 8 weeks. At week 21, rats in each group were equally divided into 6 sub-groups: normal diet fed rats treated with vehicle (NDV) sham, normal diet fed rats treated with D-gal (NDDg) sham, high fat diet fed rats treated with D-gal (HFDg) sham, high fat diet fed rats treated with vehicle (HFV) + HBOT, NDDg + HBOT and HFDg + HBOT. Sham treated rats were given normal concentration of O2 (flow rate of 80 L/min, 1 ATA for 60 minutes), whereas HBOT treated rats were subjected to 100% O2 (flow rate of 250 L/min, 2 ATA for 60 minutes), given once daily for 2 weeks.

Results

Under obese-insulin resistant condition, D-gal-induced ageing aggravated LV dysfunction (Fig 1A) and impaired cardiac mitochondrial function, increased cardiac inflammatory and apoptotic markers (Fig 1B). HBOT markedly reduced cardiac TNF-α level and TUNEL positive apoptotic cells, and improved cardiac mitochondrial function as indicated by decreased mitochondrial ROS production, mitochondrial depolarization and mitochondrial swelling, resulting in the restoration of the normal LV function in HFV and NDDg rats, compared to sham NDDg rats. In addition, in HFDg treated rats, HBOT attenuated cardiac TNF-α level, TUNEL positive apoptotic cells and cardiac mitochondrial dysfunction, compared to sham HFDg rats, leading to improved cardiac function as indicated by increased %LV ejection fraction (LVEF) (Figure 1).

Conclusion

HBOT efficiently alleviates D-gal-induced-age-related LV dysfunction through mitigating inflammation, apoptosis and mitochondrial dysfunction in pre-diabetic rats.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): 1. The National Science and Technology Development Agency Thailand, 2. Thailand Research Fund Grants

Aging induced by D-galactose aggravates cardiac dysfunction via exacerbating mitochondrial dysfunction in obese insulin-resistant rats

The prevalence of obesity and an aging population are increasing worldwide. Both obesity and aging are independently known to be associated with cardiac dysfunction. However, in obese insulin-resistant subjects, the effects of aging on metabolic status and cardiac and mitochondrial functions are not completely understood. We hypothesized that in the obese insulin-resistant condition, aging induced by D-galactose increases cardiac senescence markers and aggravates the impairment of metabolic parameters, cardiac and mitochondrial function, and increases oxidative stress, inflammation, apoptosis, and autophagy. Sixty-four male Wistar rats were fed with either normal diet (ND) or high-fat diet (HFD) for 12 weeks. Then, rats were divided into vehicle groups (0.9% NSS, subcutaneous injection (SC)) or D-galactose groups (150 mg/kg/day, SC). After 0.9%NSS or D-galactose treatment for 4 weeks and 8 weeks, metabolic and cardiac functions were determined. The heart was then removed to determine mitochondrial functions and enable biochemical studies. After 4 weeks of D-galactose injection, ND rats treated with D-galactose (NDD4), HFD rats treated with vehicle (HFV4), and HFD rats treated with D-galactose (HFD4) had reduced cardiac function, impaired cardiac mitochondrial function and autophagy, and increased oxidative stress, inflammation, and apoptosis. Interestingly, after 8 weeks, HFD rats treated with D-galactose (HFD8) had the worst impairment of cardiac and mitochondrial function, autophagy, and apoptosis in comparison to the other groups. Aging induced by D-galactose aggravated cardiac dysfunction in obese insulin-resistant rats through the worsening of cardiac mitochondrial function, autophagy, and increased apoptosis in a time-dependent manner.

Prediction of 'highly skin smear positive' cases among MB leprosy patients using clinical parameters

Although 'highly skin smear positive' MB leprosy cases are known to be at high risk of relapse after release from treatment, and have been recommended to receive 'prolonged duration' MDT, government field-based control programmes without skin smear facilities have no simple alternative method to detect such cases. This study reports a significant prevalence of 'highly smear positive' cases amongst 2374 new multibacillary cases recently surveyed by skin smears in Nepal, and retrospectively analyses 555 newly detected, previously untreated BL and LL cases to identify clinical and laboratory parameters that may be associated with a 'highly positive skin smear'. While some parameters showed high sensitivity in predicting 'highly positive smear' status, none showed both high sensitivity and high specificity simultaneously.

A comparative study of intervention methods (full, partial and non-integration) on late case detection and treatment irregularity in Yangon, Myanmar

The high percentage (20%) of new cases with grade 2 disabilities, and a low treatment regularity of 47% indicated problems in case detection and case holding in Urban Yangon. The fact that Urban Health Centers (UHCs) were not involved in leprosy control programme might have had an adverse influence. To compare the effectiveness of two methods of integration (full and partial) of urban leprosy services in terms of early case detection and regularity of treatment this study was conducted, in an urban area. Two townships with similar leprosy prevalence, staff infrastructure, socio-economic status, transport, communication and working capacity of the Township Medical Officers (TMOs) were chosen for this intervention study: UHC-A(Thingangyun) for full integration and UHC-B(Tamwe) for partial integration and the remaining 14 townships as non-integrated areas served by the Central Special Skin Clinic (CSSC). This study has shown that it was possible to fully integrate Leprosy Control Programme (LCP) into the Urban Health Centres [Basic Health Services (BHS)] in Urban Yangon. Case detection could be improved by active case finding such as contact examination and school examination conducted by the personnel of UHCs. Treatment regularity was found to be directly proportional to prompt defaulter retrieval action and the motivational level of the TMO and peripheral BHS workers. There were more complaints from patients (8.1%) treated at UHC-A when compared to CSSC (6.7%). Among defaulters there were more adults than children, more males than females and more PB than MB patients.

Acceptance of short course artesunate plus mefloquine drug combination by malaria patients in rural Myanmar

A cross sectional study was carried out in a rural area of Myanmar to identify malaria patients' acceptance of artesunate plus mefloquine drug combination and to determine the cost borne by patients. The majority (88.5%) preferred this new regimen rather than the other ones they had used before; conviction of drug efficacy was the reason given for the preference by most of them. Traveling on foot to rural health centers or a health assistant's residence for getting the drugs was found to be the main route. Average cost incurred by a patient to get the drug was found to be 274.22 Kyats. Among the cost items, drug cost was the highest item that they had used.

Leprosy elimination through integrated basic health services in Myanmar: the role of midwives

Myanmar is one of the top 16 countries identified by WHO as being hyperendemic for leprosy. Multi-drug therapy (MDT) was introduced in 1988 as a vertical programme and gradually integrated into the basic health services (BHS), achieving 100% coverage over the registered cases by 1995. To achieve maximum coverage of and benefit for patients, both leprosy vertical staff and BHS staff were trained to implement MDT whilst performing routine BHS activities. This included a total of 8615 trained midwives who were mobilized for the nationwide leprosy elimination programme (LEP). They worked at village level in various parts of the country and were willing and able to carry out basic tasks in leprosy management, such as the implementation of MDT using blister-calender packs carrying a month's supply of drugs. This study was performed to assess the workload of midwives and their attitude towards LEP. The authors conclude that midwives in Myanmar show a high level of commitment and reliability, which are essential contributing factors to achieve the current goal of leprosy elimination by the year 2000. Along with the present trend of decreasing prevalence rate, leprosy could no longer be considered as a public health problem at national level by the year 2000 in Myanmar. However, because of its long incubation period, new leprosy patients may arise even after the elimination target is achieved, whilst many other patients may become disabled. A community-based sustainable approach for the post-elimination phase, after the year 2000, will be essential and the contribution of the midwives may be of considerable importance.

Serum cortisol levels in patients with uncomplicated and cerebral malaria

Ten patients with uncomplicated malaria, ten with cerebral malaria and 37 controls (blood donors from blood bank) were included in the study. The serum cortisol levels of the patients were determined daily for 7 days while they were at the hospital. A radio-immunoassay method was used for quantitative measurement of cortisol in human serum. The mean serum cortisol level of patients with uncomplicated malaria was 528.2 +/- 123.9 nmol/l, with cerebral malaria was 516.0 +/- 80.5 nmol/l, and in controls was 393.8 +/- 141.0 nmol/l. There was a significant rise of serum cortisol levels in patients with malaria when compared to controls at the day of admission to hospital. There was no significant difference between uncomplicated malaria patients and those with cerebral malaria. There was also no significant difference between the different days of treatment up till day 7. We found no cortisol insufficiency in cases with falciparum malaria during acute and convalescent stages of illness.

Influence of blister packaging on the efficacy of artesunate + mefloquine over artesunate alone in community-based treatment of non-severe falciparum malaria in Myanmar

Three studies were carried out to determine the need, acceptability, and efficacy of adding mefloquine to artemisinin derivatives (AD) for the first-line treatment of uncomplicated falciparum malaria. The first was a retrospective study of 255 basic health workers which showed that their recommendation of AD to patients depended on their level of training. None of the paramedics/midwives and only 9% of 129 doctors had prescribed AD, and no one had recommended AD in combination with mefloquine; 72% of patients used courses that were too short for parasitological cure. To promote the addition of mefloquine to AD regimens we conducted intervention workshops with health care providers and subsidized the cost of mefloquine to patients. In the second study, we interviewed 200 patients before and after the intervention to evaluate drug compliance with full doses of AD and use of subsidized mefloquine. After the intervention, we found that only 3.6% had used mefloquine and 62% had taken non-curative doses of AD. In the third study, we provided blister packs of medication in daily doses and compared the intake of AD + placebo (158 patients) with that of AD + mefloquine (222 patients) for 5 days. The compliance with both regimens was 99%. Blood smears for parasites on day 28 showed one positive in the AD + mefloquine group and 7 positive in the AD group. We conclude that provision of blister packs of daily doses is a very effective way to improve compliance with short courses and drug combinations, but the efficacy of the combination in Myanmar in this particular study was only marginally higher than that of AD alone.

Prevalence of colour blindness among patients with leprosy

Using Ishihara test plates the prevalence of colour blindness was studied on six hundred and ninety-seven leprosy patients and two hundred and ninety-two normal healthy controls. 7.88% of male patients with tuberculoid leprosy, 12.18% of male patients with lepromatous leprosy, and 0.67% of male controls were detected to be colour blind (red-green deficiency or total colour weakness). The differences between the different groups are significant. Among female patients and controls, only one lepromatous leprosy patient was detected to have red-green deficiency. This suggests the possibility of a genetic predisposition to Mycobacterium leprae infection in patients with leprosy.

The effect of artemether plus mefloquine on Myanmar patients with complicated falciparum malaria

The effect of artemether plus mefloquine versus quinine on 35 patients with complicated falciparum malaria including 5 patients with cerebral malaria were studied. All patients treated with the artemether-mefloquine combination survived and all were free from toxic effects of the drugs. Three patients on quinine therapy died. The mortality rate was 8.5%. The mean parasite clearance time of patients treated with artemether plus mefloquine was significantly shorter than those treated with quinine but there was no significant difference in the mean fever clearance of the two groups of patients. There was no recrudescence with artemether and mefloquine; the recrudescence rate was 5.5% with quinine. The study showed that the artemether-mefloquine combination is superior to quinine for the treatment of patients with complicated falciparum malaria, including cerebral malaria.

Estimation of leprosy prevalence in Bago and Kawa townships using two-stage probability proportionate to size sampling technique

Two surveys to estimate leprosy prevalence using two-stage probability proportionate to size sampling technique were conducted in Bago and Kawa townships. A total of 3519 and 3739 individuals were examined in each township. The two surveys were finished within 25 (Bago) and 30 (Kawa) working days at a cost of Kyats 10,000 (US $1500) for each survey. The estimated leprosy prevalence obtained in Bago was 9.95 per 1000 population (95% confidence interval (CI): 7.11-12.78) and in Kawa it was 12.04 per 1000 population (95% CI: 8.85-15.22). A total of 30 (Bago) and 34 (Kawa) new leprosy cases were detected in the two surveys. Grade I disability was seen to be 20% in Bago and 18.78% in Kawa, whereas grade II disability was 17.14% in Bago and 15.56% in Kawa.

The effect of tetanus toxoid in leprosy patients

Since cases of lepra reaction following smallpox vaccination and BCG vaccination had been reported the effect of tetanus immunisation on leprosy patients (whether it may provoke a lepra reaction or not) was studied. Three doses of purified tetanus toxoid (one ml initially, one ml after six weeks and one ml after six months) were given to 357 leprosy patients and 60 patients living in the same environ were followed as controls. The antibody response following immunisation was followed in six lepromatous leprosy patients using toxin antitoxin neutralisation test at the Lf/1000 level in mice and in three of them the antibody titre of leprosy patients rose to satisfactory level. The number of lepra reactions in these patients was monitored for nine months (two months before vaccination, during the six months period of vaccination and one month after the last dose of vaccine). There was no significant rise in the number of patients with reaction following the vaccination.

The effect of mefloquine-sulfadoxine-pyrimethamine vs quinine on patients with complicated falciparum malaria

Sixty-six patients with complicated falciparum malaria (defined as anaemia, hyperpyrexia, jaundice, or more than 2% of RBC parasitised) were studied. Patients with cerebral signs and symptoms were not included in the study. Patients were randomised in pairs to receive either mefloquine 750 mg, sulfadoxine 1500 mg and pyrimethamine 75 mg (MSP) single oral dose or quinine (10 mg/kg tds X 7 days oral therapy). All the patients were admitted in hospital for 7 days and were followed on days 14, 21 and 28. All patients survived. The parasite clearance times in MSP treated patients were significantly shorter then those treated with quinine. There was no difference in fever clearance time in the two groups of patients. One patient was resistant to MSP at RII level and 5 patients were resistant at RI level. Among patients treated with quinine 3 patients were resistant at RI level.

Australia antigen and antibody in British patients with leprosy

Seventy-five sera collected from leprosy patients in England were tested for Australia antigen and antibody. Australia antigen was detected in only two patients with lepromatous leprosy and in one patient with borderline pure leprosy. Antibody to Australia antigen was found in one patient with lepromatous leprosy. These findings differ from previous reports and it is suggested that the frequency of Australia antigen in lepromatous leprosy is a function of the incidence of this antigen in the general population rather than increased genetic susceptibility to chronic infection.

Nephrotic syndrome in monkey infected with human quartan malaria

A splenectomized aotus monkey infected with human quartan malaria (Plasmodium malariae) developed oedema and proteinuria. Histological examination revealed a generalized diffuse glomerulonephritis and immunofluorescent staining showed granular deposits of IgM in the glomeruli. The pathological picture resembled that shown by human patients with the quartan malaria nephrotic syndrome.