Antimicrobial properties of Allium sativum (garlic)

Although garlic has been used for its medicinal properties for thousands of years, investigations into its mode of action are relatively recent. Garlic has a wide spectrum of actions; not only is it antibacterial, antiviral, antifungal and antiprotozoal, but it also has beneficial effects on the cardiovascular and immune systems. Resurgence in the use of natural herbal alternatives has brought the use of medicinal plants to the forefront of pharmacological investigations, and many new drugs are being discovered. This review aims to address the historical use of garlic and its sulfur chemistry, and to provide a basis for further research into its antimicrobial properties.

The spectrum of inherited mutations causing HPRT deficiency: 75 new cases and a review of 196 previously reported cases

In humans, mutations in the gene encoding the purine salvage enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT) are associated with a spectrum of disease that ranges from hyperuricemia alone to hyperuricemia with profound neurological and behavioral dysfunction. Previous attempts to correlate different types or locations of mutations with different elements of the disease phenotype have been limited by the relatively small numbers of available cases. The current article describes the molecular genetic basis for 75 new cases of HPRT deficiency, reviews 196 previously reported cases, and summarizes four main conclusions that may be derived from the entire database of 271 mutations. First, the mutations associated with human disease appear dispersed throughout the hprt gene, with some sites appearing to represent relative mutational hot spots. Second, genotype-phenotype correlations provide no indication that specific disease features associate with specific mutation locations. Third, cases with less severe clinical manifestations typically have mutations that are predicted to permit some degree of residual enzyme function. Fourth, the nature of the mutation provides only a rough guide for predicting phenotypic severity. Though mutation analysis does not provide precise information for predicting disease severity, it continues to provide a valuable tool for genetic counseling in terms of confirmation of diagnoses, for identifying potential carriers, and for prenatal diagnosis.

Dopamine transporters are markedly reduced in Lesch-Nyhan disease in vivo

Dopamine (DA) deficiency has been implicated in Lesch-Nyhan disease (LND), a genetic disorder that is characterized by hyperuricemia, choreoathetosis, dystonia, and compulsive self-injury. To establish that DA deficiency is present in LND, the ligand WIN-35,428, which binds to DA transporters, was used to estimate the density of DA-containing neurons in the caudate and putamen of six patients with classic LND. Comparisons were made with 10 control subjects and 3 patients with Rett syndrome. Three methods were used to quantify the binding of the DA transporter so that its density could be estimated by a single dynamic positron emission tomography study. These approaches included the caudate- or putamen-to-cerebellum ratio of ligand at 80-90 min postinjection, kinetic analysis of the binding potential [Bmax/(Kd x Vd)] using the assumption of equal partition coefficients in the striatum and the cerebellum, and graphical analysis of the binding potential. Depending on the method of analysis, a 50-63% reduction of the binding to DA transporters in the caudate, and a 64-75% reduction in the putamen of the LND patients was observed compared to the normal control group. When LND patients were compared to Rett syndrome patients, similar reductions were found in the caudate (53-61%) and putamen (67-72%) in LND patients. Transporter binding in Rett syndrome patients was not significantly different from the normal controls. Finally, volumetric magnetic resonance imaging studies detected a 30% reduction in the caudate volume of LND patients. To ensure that a reduction in the caudate volume would not confound the results, a rigorous partial volume correction of the caudate time activity curve was performed. This correction resulted in an even greater decrease in the caudate-cerebellar ratio in LND patients when contrasted to controls. To our knowledge, these findings provide the first in vivo documentation of a dopaminergic reduction in LND and illustrate the role of positron emission tomography imaging in investigating neurodevelopmental disorders.

Self-injurious behavior: gene-brain-behavior relationships

This paper summarizes a conference held at the National Institute of Child Health and Human Development on December 6-7, 1999, on self-injurious behavior [SIB] in developmental disabilities. Twenty-six of the top researchers in the U.S. from this field representing 13 different disciplines discussed environmental mechanisms, epidemiology, behavioral and pharmacological intervention strategies, neurochemical substrates, genetic syndromes in which SIB is a prominent behavioral phenotype, neurobiological and neurodevelopmental factors affecting SIB in humans as well as a variety of animal models of SIB. Findings over the last decade, especially new discoveries since 1995, were emphasized. SIB is a rapidly growing area of scientific interest to both basic and applied researchers. In many respects it is a model for the study of gene-brain-behavior relationships in developmental disabilities.

Synthesis of allysine ethylene acetal using phenylalanine dehydrogenase from Thermoactinomyces intermedius

Allysine ethylene acetal [(S)-2-amino-5-(1,3-dioxolan-2-yl)-pentanoic acid (2)] was prepared from the corresponding keto acid by reductive amination using phenylalanine dehydrogenase (PDH) from Thermoactinomyces intermedius ATCC 33205. Glutamate, alanine, and leucine dehydrogenases, and PDH from Sporosarcina species (listed in order of increasing effectiveness) also gave the desired amino acid but were less effective. The reaction requires ammonia and NADH. NAD produced during the reaction was recyled to NADH by the oxidation of formate to CO(2) using formate dehydrogenase (FDH). PDH was produced by growth of T. intermedius ATCC 33205 or by growth of recombinant Escherichia coli or Pichia pastoris expressing the Thermoactinomyces enzyme. Using heat-dried T. intermedius as a source of PDH and heat-dried Candida boidinii SC13822 as a source of FDH,98%, but production of T. intermedius could not be scaled up. Using heat-dried recombinant E. coli as a source of PDH and heat-dried Candida boidinii 98%. In a third generation process, heat-dried methanol-grown P. pastoris expressing endogenous FDH and recombinant Thermoactinomyces98% ee.

Craniocerebral magnetic resonance imaging measurement and findings in Lesch-Nyhan syndrome

OBJECTIVE

To provide the first comprehensive magnetic resonance imaging (MRI) assessment of brain in a series of patients with Lesch-Nyhan syndrome (LNS), with emphasis on basal ganglia measurements.

DESIGN

Routine readings of MRI studies, repeated reading in random order blinded to subject diagnosis, and 3-dimensional volumetric measures of basal ganglia regions.

SETTING

The Johns Hopkins Hospital, Baltimore, Md.

PATIENTS

Seven patients with LNS who have hypoxanthine guanine phosphoribosyltransferase levels less than 1.6% and characteristic clinical features of the disorder, which include hyperuricemia, cognitive impairment, and dystonic movement disorder, were compared with 7 age-matched control subjects. Five of the 7 patients demonstrated self-injurious behavior. MRI studies were performed using general anesthesia because of the severity of the movement disorder.

MAIN OUTCOME MEASURES

Measurement of brain regions from MRI-obtained images.

RESULTS

Routine readings described mild cerebral atrophy in 2 of 7 patients, but no caudate or putamen abnormalities were reported. However, on the directed blinded rereading, small caudates were suspected in 5 of 7 cases, and abnormalities in cerebral size and cranium were identified. Volumetric studies of the patients with LNS confirmed a 34% decrease in caudate volume (P<.001), a 17% decrease in total cerebral volume (P<.03), and a 12% decrease in putamen volume (P=.19).

CONCLUSIONS

To our knowledge, this is the first demonstration of consistent neuroanatomic abnormalities in LNS. The findings of reduced basal ganglia volume are consistent with the dystonic movement disorder.

Hyperlexia in infantile autism

Twenty boys meeting the current DSM III criteria for infantile autism at the time of diagnosis were found to be hyperlexic in childhood and have been followed up for 7-17 years. The most striking feature of the group was the compulsion to decode written material without comprehension of its meaning, and this constituted a behavioral phenotype for this population. On word recognition tests such as the WRAT, they scored significantly higher than would be predicted on the basis of intelligence but demonstrated severe reading retardation on tests of reading comprehension such as the Gates-McGinitie. Major differences in intelligence were detected, ranging from severe mental retardation to very superior intelligence. Major differences in verbal and nonverbal abilities were also noted. Many were found to have unusually good memory, both visual and auditory, and the majority possessed an excellent stored vocabulary that could be used with written words despite the poverty of their expressive language. It is suggested that the presence of hyperlexia may identify a subgroup of autistic children.

The spectrum of mutations causing HPRT deficiency: an update

Mutations in the gene encoding hypoxanthine-guanine phosphoribosyltransferase (HPRT) cause Lesch-Nyhan disease, which is characterized by hyperuricemia, severe motor disability, and self-injurious behavior. Mutations in the same gene also cause less severe clinical phenotypes with only some portions of the full syndrome. A large database of 271 mutations associated with both full and partial clinical phenotypes was recently compiled. Since the original database was assembled, 31 additional mutations have been identified, bringing the new total to 302. The results demonstrate a very heterogeneous collection of mutations for both LND and its partial syndromes. The differences between LND and the partial phenotypes cannot be explained by differences in the locations of mutations, but the partial phenotypes are more likely to have mutations predicted to allow some residual enzyme function. The reasons for some apparent exceptions to this proposal are addressed.

Ontogeny of noradrenergic effects on ultrasonic vocalizations in rat pups

The ontogeny of noradrenergic effects and the interaction of opioid and noradrenergic systems on vocalizations in rat pups from Day 10 to Day 18 were evaluated. Day 10 pups given clonidine (0.05 or 0.5 mg/kg) ip showed a sustained high level of calling throughout a 25-min isolation period that was reversed with yohimbine (0.1 mg/kg). Day 15 pups showed identical profiles with a lower baseline rate. Day 17 pups' calls were differentially affected according to dose; Day 18 pups reduced vocalizing with clonidine. In addition, it was found that at all ages when clonidine increased calling during isolation, the pups vocalized in the nest as well. Naltrexone, an opioid antagonist, lost its effectiveness to increase vocalizations after Day 15 unless it was given subsequent to clonidine. These results suggest that pups' vocalizations are differentially affected by noradrenergic and opioid stimulation or inhibition with developmental changes.

Neurocognitive functioning in Lesch-Nyhan disease and partial hypoxanthine-guanine phosphoribosyltransferase deficiency

Lesch-Nyhan disease (LND) is a rare, X-linked genetic disorder that involves the nearly complete absence of an enzyme (hypoxanthine-guanine phosphoribosyltransferase, or HPRT) that is essential for purine salvage. In addition to hyperuricemia, all patients with classic LND suffer from movement disorder and compulsive self-injury, and most have mental retardation. Patients with partial HPRT deficiency (variants) always have hyperuricemia and often have neurologic abnormalities, but do not self-injure and usually are described as having normal intelligence. Here we compare 15 patients with LND to 9 variants and 13 normal adolescents and adults. Testing revealed unambiguous and qualitatively similar cognitive deficits in both patient groups. The variants produced scores that were intermediate between those of patients with LND and normal participants on nearly every cognitive measure. We discuss these findings in terms of what is known about the neuropathology of LND.

Mediation of separation distress by alpha 2-adrenergic mechanisms in a non-human primate

This study provides the first behavioral evidence in support of an alpha-adrenergic mechanism underlying imipramine's amelioration of separation distress. The rate of separation-induced vocalization by adult squirrel monkeys was decreased by imipramine and the alpha 2-adrenergic agonist clonidine, and increased by the alpha 2-adrenergic antagonist yohimbine. Yohimbine, but not the alpha 1-antagonist prazosin, reversed the clonidine effect suggesting that drugs acting directly on alpha 2-receptors may have a role in management of separation anxiety.

Is excessive daytime sleepiness characteristic of Prader-Willi syndrome? The effects of weight change

OBJECTIVES

To assess nighttime and daytime sleep patterns in patients with Prader-Willi syndrome and to examine the effects of weight change on excessive daytime sleepiness in patients with this disorder.

DESIGN

Case series (within-subject design).

SETTING

A university sleep disorders center.

PATIENTS

Eight patients (5 males and 3 females), ranging in age from 5.5 to 21 years, who met the diagnostic criteria for Prader-Willi syndrome.

INTERVENTIONS

Overnight sleep polysomnographic recording and daytime Multiple Sleep Latency Test. Four of the 8 patients were restudied after their weight had changed.

MAIN OUTCOME MEASURES

Changes in the sleep disordered breathing rate and Multiple Sleep Latency Test measures.

RESULTS

Sleep-disordered breathing occurred in all patients and was principally characterized by obstructive hypoventilation or episodes of apnea that occurred primarily during rapid eye movement sleep. After weight reduction, 3 patients had respiratory values that were within the broad normal range (disordered breathing rate, < 15 breaths per hour). Statistically significant (P < .05) weight loss effects occurred during nonrapid eye movement sleep (decrease with weight loss, F = 6.243). Excessive daytime sleepiness was documented in 6 of 7 patients who completed the Multiple Sleep Latency Test. Excessive daytime sleepiness was not consistently correlated with body weight or any of the nocturnal sleep variables.

CONCLUSIONS

A sleep-related breathing disorder occurred during rapid eye movement and nonrapid eye movement sleep and improved with weight change in patients with Prader-Willi syndrome, emphasizing the importance of weight reduction in clinical management. However, excessive daytime sleepiness persisted despite a reduction in sleep-disordered breathing after weight loss, suggesting a primary disturbance of sleep. Our findings provide additional support for the view that primary hypersomnia is a characteristic feature of the Prader-Willi syndrome.

Antigiardial drugs

Giardia intestinalis is a world-wide cause of intestinal infection. Treatment of this debilitating disease is usually accomplished using one of several drugs. Metronidazole is the treatment of choice, but benzimidazoles are now being used more frequently. Other treatments include quinacrine, paromomycin and furazolidone. Even though these drugs are all used to treat the same disease, their modes of action differ in all cases. However, resistance is increasing and new alternatives are being sought. New wave antigiardials all appear to have their roots in natural herbal remedies. This mini-review looks at the current treatments available, their efficacy, side effects and different modes of action and addresses a possible way forward using natural products.

Hepatitis B in ward and clinical laboratory employees of a general hospital

After a sharp increase in viral hepatitis cases, mostly type B, among the 2000 employees of a general hospital during three years, we conducted an investigation which consisted of obtaining data on employee cases and surveying many current employees. Of the 38 cases, 22 occurred in non-physician, ward employees. Of 189 current ward employees, 8% had antibody to hepatitis B surface antigen (anti-HBS) and 1% had hepatitis B surface antigen (HBSAg). Hepatitis B virus (HBV) seropositivity was highest for employees who worked closely with hemodialysis and renal transplant patients and for those who claimed that their ward was understaffed. Nine of the 38 cases occurred in clinical lab workers. Of 70 current lab employees, 17% were positive for anti-HBS and none for HBSAg. HBV seropositivity was highest for those working in the chemistry section (highest there among those performing blood-gas determinations and those working with the multi-channel autoanalyzers) and those who routinely got blood on their skin and clothes at work. All seropositive employees worked routinely with blood. These data support the hypotheses that many hospital employees contract hepatitis B from exposure to HBSAg-positive patients and many clinical laboratory employees contract it from exposure to HBV-contaminated blood.

Safeguarding children in dentistry: 2. Do paediatric dentists neglect child dental neglect?

In this second part of a two-part report, further findings of a postal questionnaire sent in March 2005 to dentists with an interest in paediatric dentistry working in varied UK settings are presented and discussed in the context of current multi-agency good practice in safeguarding and promoting the welfare of children. Using insights gained from a survey of self-reported management of children with neglected dentitions, this paper explores whether paediatric dentists neglect child dental neglect. The authors conclude that current practice already includes much that contributes to promoting children's oral health and wellbeing. However, in a society where children continue to suffer as a result of abuse and neglect, they warn that improvements are needed in communication between dentists and other health and social care professionals if children's welfare is to be safeguarded and promoted effectively and future tragedies avoided.

The plasma membrane of microaerophilic protists: oxidative and nitrosative stress

The trans-plasma-membrane electrochemical potential of microaerophilic protists was monitored by the use of voltage-sensitive charged lipophilic fluorophores; of the many available probes, the anionic oxonol dye bis(1,3-dibarbituric acid)-trimethine oxonol [DiBAC4(3)] is an example of one which has been successfully employed using fluorescence microscopy, confocal laser-scanning microscopy and flow cytometry. Several microaerophilic protists have been investigated with this dye; these were Giardia intestinalis, Trichomonas vaginalis, Tritrichomonas foetus, Hexamita inflata and Mastigamoeba punctachora. Under conditions where they exhibit normal vitality, these organisms exclude DiBAC4(3) by virtue of their maintenance of a plasma-membrane potential (negative inside). Uptake of the fluorophore is indicative of disturbance to this membrane (i.e. by inhibition of pump/leak balance, blockage of channels or generation of ionic leaks), and is indicative of metabolic perturbation or environmental stress. Here, it is shown that oxidative or nitrosative stress depolarizes the plasma membranes of the aforementioned O2-sensitive organisms and allows DiBAC4(3) influx. Oxonol uptake thereby provides a sensitive and early indication of plasma-membrane perturbation by agents that may lead to cytotoxicity and eventually to cell death by necrotic or apoptotic pathways.

Positron emission tomographic study of D2 dopamine receptor binding and CSF biogenic amine metabolites in Rett syndrome

We report on the first positron emission tomographic study of dopamine receptor binding in Rett syndrome. The patient is a 25 year old Austrian woman diagnosed at age 2 and followed since then by Rett. A computed axial tomogram (CT scan) showed cortical atrophy, and enlarged ventricles but normal structure of the caudate/putamen. Following the CT scan 20 mCi of 11 C N-methyl spiperone, a butyrophenone with a high affinity for dopamine D2 receptors was administered intravenously. The patient was found to have dopamine D2 receptor binding activity in the low normal range. The caudate/cerebellar activity ratio was below the mean regression line (p = 0.10) that relates the CA/CB ratio as a function of age. Levels of cerebrospinal fluid neurotransmitter metabolites were normal.

Ocular motor dysfunction in Lesch-Nyhan disease

Eye movements were assessed in 22 patients with varying degrees of hypoxanthine-guanine phosphoribosyltransferase deficiency. Ocular motility was clinically normal in seven patients with moderate enzyme deficiency but grossly abnormal in 15 patients with severe enzyme deficiency. In patients with severe deficiency, fixation was interrupted by frequent unwanted saccades toward minor visual distractions. Voluntary saccades were associated with an initial head movement and/or eyeblink in all of these patients. When head motion was prevented, voluntary saccades were often delayed and sometimes absent. In contrast, saccade speed, reflexive saccades, and other reflexive eye movements appeared clinically normal. Four patients with severe enzyme deficiency also experienced mild blepharospasm, and two had ocular tics. These disturbances of ocular motility are consistent with dysfunction of the basal ganglia or its connections with ocular motor centers in the prefrontal cortex or midbrain.

Are the Twelve Steps more acceptable to drug users than to drinkers? A comparison of experiences of and attitudes to Alcoholics Anonymous (AA) and Narcotics Anonymous (NA) among 200 substance misusers attending inpatient detoxification

The present study is a cross-sectional interview-based investigation comparing experiences of and attitudes towards Alcoholics Anonymous (AA) and Narcotics Anonymous (NA) in a sample of 200 patients attending inpatient substance misuse detoxification services. Two hundred consecutive admissions were recruited; 100 each from one drug and one alcohol in-patient treatment service in which attendance at AA/NA was a voluntary adjunct to a generic treatment programme. Although there were no differences in the history of AA/NA attendance, the drug users (who were on average younger) reported significantly more positive attitudes towards AA/NA, more willingness to attend during their in-patient treatment and greater intention to attend following completion of their detoxification. In particular, despite no differences in spiritual/religious orientation, the drug users reported more positive views of the Twelve Steps. As AA/NA remain popular and accessible forms of substance misuse support, it is critical that we develop a clearer understanding of their impact and of the scope for their integration with generic forms of substance misuse treatment.

Nitrosative stress induced cytotoxicity in Giardia intestinalis

AIMS

To investigate the antigiardial properties of the nitrosating agents: sodium nitrite, sodium nitroprusside and Roussin's black salt.

METHODS AND RESULTS

Use of confocal laser scanning microscopy and flow cytometry indicated permeabilization of the plasma membrane to the anionic fluorophore, DiBAC4(3) [bis(1,3-dibutylbarbituric acid) trimethine oxonol]. Loss of plasma membrane electrochemical potential was accompanied by loss of regulated cellular volume control. Changes in ultrastructure revealed by electron microscopy and capacity for oxygen consumption, were also consequences of nitrosative stress. Roussin's black salt (RBS), active at micromolar concentrations was the most potent of the three agents tested.

CONCLUSIONS

These multitargeted cytotoxic agents affected plasma membrane functions, inhibited cellular functions in Giardia intestinalis and led to loss of viability.

SIGNIFICANCE AND IMPACT OF THE STUDY

Nitrosative damage, as an antigiardial strategy, may have implications for development of chemotherapy along with suggesting natural host defence mechanisms.

Comparative efficacy of injectable calcium and magnesium salts in the therapy of hydrofluoric acid burns

Hydrofluoric acid (HF) causes severe skin burns which often progress in severity despite physiologic neutralization. The currently accepted therapy is the subcutaneous injection of calcium (Ca) gluconate to precipitate the residual free fluoride ion. Magnesium (Mg) also forms an insoluble fluoride salt and is less tissue irritating than Ca. This study compared the effects of subcutaneous injection of saline, Ca gluconate, Mg acetate (MgAc), and Mg sulfate (MgSO4) on lesions resulting from HF burns in rats. Burns treated with either Mg compound healed 3.7 +/- 1.7 days faster (p less than 0.05) developed less severe lesions (p less than 0.01) and exhibited left untreated or treated with saline. There was no difference in the incidence of infection between the study groups. The effects of burns treated with calcium were statistically similar to the control groups. This study suggests that Mg may be more effective than Ca in minimizing the duration, depth, and progression of dermal HF burns.

Solution structure of a biologically active cyclic LDV peptide analogue containing a type II' beta-turn mimetic

The solution structure of cyclo-[Gly-Leu-Asp-Val-BTD] (BTD = beta-turn dipeptide) has been determined by two-dimensional 1H-NMR (nuclear magnetic resonance) spectroscopy and systematic conformational searching combined with molecular dynamics studies. The structure contains two hydrogen bonds between the Gly and Val residues, and a type I beta-turn with Leu and Asp at the (i + 1) and (i + 2) positions of the turn. The cyclic compound shows activity in a scintillation proximity assay (SPA) for the inhibition of the interaction between the integrin alpha 4 beta 1 and vascular cell adhesion molecule-1 (VCAM-I). The structure-activity relationship of the LDV sequence is discussed.