Effect of non-ß-lactams on stable variants of inhibitor-resistant TEM ß-lactamase in uropathogenic Escherichia coli: implication for alternative therapy.

AIMS: ß-lactamase inhibitor resistance (BLIR) among the uropathogenic Escherichia coli (UPEC) minimizes treatment options. This study aimed to identify inhibitor-resistant TEM (IRT) ß-lactamase that impart BLIR phenotype and explore non-ß-lactams as alternative therapeutics. METHODS AND RESULTS: Thirty BLIR UPEC isolates were detected by Kirby-Bauer disc diffusion technique using ß-lactam-ß-lactamase inhibitor combination. Conjugal transfer of BLIR was successful from 17 isolates. PCR and sequencing of the TEM ß-lactamases from the transconjugants indicated 14 TEM-84 (IRT) and three novel IRT variants (pUE184TEM, pUE203TEM, pUE210TEM). Three-dimensional models of the latter were predicted and validated. Molecular docking of selected non-ß-lactams (morin, catechin, naringenin triacetate) with the variants using AutoDock 4.2 showed comparable docking scores with significant hydrogen bond and hydrophobic interactions. Molecular dynamics simulation study confirmed stability of the non-ß-lactams inside the catalytic pocket of the enzymes. Moreover, all three non-ß-lactams were found to inhibit the purified TEM ß-lactamase variants in vitro. Microbroth dilution method indicated naringenin triacetate 64 µg ml-1 in combination with ceftazidime (CAZ) 30 µg ml-1 to be most effective against the BLIR transconjugants. CONCLUSIONS: BLIR phenotypes were primarily attributed to the production of IRT ß-lactamases. Administration of the non-ß-lactams with CAZ demonstrated an alternative therapeutic strategy against the IRT ß-lactamase producers. SIGNIFICANCE AND IMPACT OF THE STUDY: This study indicates high risk of transmission of IRT ß-lactamases and suggests ß-lactam-non-ß-lactam combination therapy to combat BLIR.

Iron deficiency anaemia in sickle cell disorders in India.

BACKGROUND & OBJECTIVE: Iron deficiency anaemia (IDA) is uncommon in individuals with sickle cell disease (SCD) because of availability of an adequate iron source potentially from increased red cell turnover and from blood transfusions. Also, iron deficiency anaemia can often go unnoticed because the sickle cell disease patients are already anaemic. Iron deficiency in sickle cell patients may result in lowering the intracellular haemoglobin concentration and this may ameliorate sickling. The present study was undertaken to determine the prevalence of iron deficiency anaemia and the response of iron supplementation in sickle cell disorders in tribal population of the four States viz. Maharashtra, Gujarat, Orissa and Tamil Nadu. METHODS: A total of 8434 individuals (7105 AA, 1267 AS and 62 SS) were tested for zinc protoporphyrin/haem (ZPP/H) ratio and haemoglobin levels. Twenty two sickle cell anaemia (SS), 47 sickle cell trait (AS) and 150 normal control (AA) individuals who were iron deficient, were given iron therapy for a period of 12 wk and the laboratory investigations were repeated at the 13th wk. RESULTS: Sixty seven per cent of subjects with sickle cell anaemia and 26 per cent with sickle cell trait had elevated ZPP/H ratios (>80 micromol/mol) as against 22.8 per cent of normal individuals. The elevated ZPP/H ratios is an indicator of microcytic anaemia of iron deficiency. Following iron therapy, an improvement in the Hb levels and ZPP/H ratios was observed in both sickle cell disorders and normal individual cases. INTERPRETATION & CONCLUSION: This study suggests that iron deficiency anaemia is an important problem in Indian sickle cell anaemia patients and iron supplementation should be given only in proven cases of iron deficiency anaemia.

Encoding, rehearsal, and recall in signers and speakers: shared network but differential engagement.

Short-term memory (STM), or the ability to hold verbal information in mind for a few seconds, is known to rely on the integrity of a frontoparietal network of areas. Here, we used functional magnetic resonance imaging to ask whether a similar network is engaged when verbal information is conveyed through a visuospatial language, American Sign Language, rather than speech. Deaf native signers and hearing native English speakers performed a verbal recall task, where they had to first encode a list of letters in memory, maintain it for a few seconds, and finally recall it in the order presented. The frontoparietal network described to mediate STM in speakers was also observed in signers, with its recruitment appearing independent of the modality of the language. This finding supports the view that signed and spoken STM rely on similar mechanisms. However, deaf signers and hearing speakers differentially engaged key structures of the frontoparietal network as the stages of STM unfold. In particular, deaf signers relied to a greater extent than hearing speakers on passive memory storage areas during encoding and maintenance, but on executive process areas during recall. This work opens new avenues for understanding similarities and differences in STM performance in signers and speakers.

Role of peritoneal macrophages and lymphocytes in the development of hypogonadal osteoporosis in an ovariectomized rat model: possible phytoestrogenic efficacy of oil extract of garlic to preserve skeletal health.

This study was to examine whether skeletal health deterioration in the hypogonadal situation is a consequence of an alteration in the functional status of peripheral mononuclear cells and its amelioration, if any, by an oil extract of garlic. The results suggest that hypogonadism-induced oxidative stress of peritoneal macrophages and lymphocytes could be reduced by supplementation with an oil extract of garlic. However, estrogen deficiency did not cause any significant change in DNA fragmentation of peritoneal macrophages. The hypogonadism-induced increase in the serum levels of IL-6 and TNF-alpha were significantly reduced by an oil extract of garlic. Further, such supplementation could revive the hypogonadism-induced decrease in serum estrogen titer and counter-balance the increase in bone turnover as determined by low bone tensile strength and alterations in bone related biochemical variables such as urinary calcium, hydroxyproline, calcium to creatinine ratio and serum tartrate resistant acid phosphatase activity (TRAP). The garlic oil supplemented partial recovery of the serum estrogen titer in hypogonadal rats was found to be persistently associated with reduced oxidative stress of peritoneal macrophages and lymphocytes, reduced serum interleukins and better preservation of bone mass. This study proposes that the hypogonadism-induced bone loss has a direct correlation with the functional status of lymphocytes and peritoneal macrophages, and garlic can prevent this.

Effects of garlic oil on postmenopausal osteoporosis using ovariectomized rats: comparison with the effects of lovastatin and 17beta-estradiol.

The purpose of this study was to examine the antiosteoporosis effects of garlic oil in an ovariectomized (Ovx) rat model of osteoporosis and to compare its efficacy with lovastatin (a synthetic hypocholesterolemic drug) and 17beta-estradiol (a potent antiosteoporotic agent). Animals were divided into five groups: sham-operated control, ovariectomized, ovariectomized supplemented with lovastatin, ovariectomized supplemented with garlic oil and ovariectomized supplemented with 17beta-estradiol. In our study, the development of a high rate of bone turnover and osteoporosis in the ovariectomized animals were confirmed by significant alterations of serum alkaline phosphatase activity, serum tartrate-resistant acid phosphatase activity, urinary excretion of calcium, phosphate, hydroxyproline and urinary calcium to creatinine ratio, when compared with the sham-operated control group. Supplementation of these animals with either garlic oil or lovastatin or 17beta-estradiol, in addition to their hypocholesterolemic effect, could counterbalance all these changes. The results revealed that all three compounds significantly protected the hypogonadal bone loss as reflected by higher bone densities and higher bone mineral contents than the ovariectomized group of animals. The results emphasize that, like 17beta-estradiol, the hypocholesterolemic compounds garlic oil and lovastatin are also effective in suppressing bone loss owing to estrogen deficiency and their efficacy in the order of lower to higher is garlic < lovastatin < 17beta-estradiol.

Prevention of bone loss by oil extract of garlic (Allium sativum Linn.) in an ovariectomized rat model of osteoporosis.

The effects of oil extract of garlic (Allium sativum Linn.) on different primary and secondary osteoporotic marker changes were tested in an ovariectomized rat model of osteoporosis. Experiments were performed on three different rat models: sham-operated control, ovariectomized and ovariectomized supplemented with garlic oil. In ovariectomized group, there has been a significant increase in different relative organ weights compared to sham-operated control, while the uterine weight was found to be decreased. Supplementation with oil extract of garlic could effectively reverse these changes. Also low bone densities that developed in the ovariectomized group were significantly recovered in the garlic oil supplemented group. In our study, the development of high rate of bone turnover and osteoporosis in the ovariectomized animals were confirmed by significant alteration of serum alkaline phosphatase activity, serum tartrate resistant acid phosphatase activity, urinary excretion of calcium, phosphate, hydroxyproline and urinary calcium to creatinine ratio, when compared with the sham-operated control group. Garlic oil extract supplementation, apart from its unique influence in lowering blood cholesterol, could also prevent ovariectomy-induced rise in all the above-mentioned marker changes. The results of this study emphasize that oil extract of garlic possibly has a positive role in suppressing ovariectomy-induced bone resorption.

Central cooling effects in patients with hypercholesterolaemia.

1. A prospective study has been carried out, and 68 patients with hypercholesterolaemia have been investigated to study the effects of central cooling on serum lipid levels. 2. Central cooling was obtained by the exposure of the whole body to cold water. All patients were trained to gradually reduce the water temperature from 22 to 14 degrees C and to increase the time of exposure from 5 to 20 min over a period of 90 days. The 33 male and 35 female patients were aged between 40 and 60 years at entry with total cholesterol of 6.0 mmol/l or greater and low-density lipoprotein (LDL)-cholesterol of 4. 0 mmol/l or greater. Thyroid-stimulating hormone, free thyroxine (FT4), total T3, total cholesterol, LDL-cholesterol, high-density lipoprotein (HDL)-cholesterol, triacylglycerols and total fat mass (determined by dual-energy X-ray absorptiometry scan) were obtained at baseline and after 3 months treatment with hydrotherapy. 3. Central cooling obtained by hydrotherapy results in a median fall in tympanic temperature from 0.2 degrees C (P<0.001) to 0.8 degrees C (P<0.001). We have observed in these patients a significant reduction in total cholesterol (-0.2 mmol/l, P=0.006) and LDL-cholesterol (-0.2 mmol/l, P=0.004). Serum FT4 level was higher than baseline results in 30 of these hypercholesterolaemic patients (15.5 pmol/l to 17.3 pmol/l) and there was no significant change in serum thyroid-stimulating hormone and total T3. 4. In conclusion, in our patients with hypercholesterolaemia we have observed a significant reduction of total cholesterol and LDL-cholesterol after body temperature regulation.