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Biomedical subjects

H Altman

Publications and source records attributed to H Altman.

At least 19 recordsLinked to original sources
PubMed2006

In vitro assessment of antimicrobial peptides as potential agents against several oral bacteria.

BACKGROUND: Antimicrobial peptides are components of the innate immunity that play an important role in systemic and oral health. OBJECTIVES: The antibacterial activity of the amphibian-derived K4 -S4(1-15)a antimicrobial peptide was tested against oral pathogens associated with caries and periodontitis and compared with the activities of the human-derived antimicrobial peptides LL-37 and dhvar4a. METHODS: Growth inhibition of planktonic bacteria was tested using standard microdilution assays. Live/Dead staining followed by confocal scanning laser microscopy (CSLM) was used to determine the bactericidal effect of K4 -S4(1-15)a on Streptococcus mutans attached to a glass surface or grown as biofilm. RESULTS: The cariogenic species S. mutans, Streptococcus sobrinus, Lactobacillus paracasei and Actinomyces viscosus were resistant to LL-37 found in the oral cavity. Porphyromonas gingivalis was the species most resistant to the three tested peptides. K4 -S4(1-15)a demonstrated the highest activity against the tested planktonic bacteria. In addition, K4 -S4(1-15)a was bactericidal to surface-attached S. mutans as well as to S. mutans biofilms grown in vitro. However, surface attachment increased S. mutans resistance to the antimicrobial peptide. CONCLUSIONS: Our results support growing evidence suggesting the use of antimicrobial peptides for prevention and treatment of oral disease.

Anti-Bacterial Agents↗
PubMed2004

Food-drug interaction: grapefruit juice augments drug bioavailability--mechanism, extent and relevance.

More than a decade has passed since it was unintentionally discovered that grapefruit juice interacts with certain drugs. The coadministration of these drugs with grapefruit juice can markedly elevate drug bioavailability, and can alter pharmacokinetic and pharmacodynamic parameters of the drug. The predominant mechanism for this interaction is the inhibition of cytochrome P-450 3A4 in the small intestine, resulting in a significant reduction of drug presystemic metabolism. An additional mechanism is, presumably, the inhibition of P-glycoprotein, a transporter that carries drug from the enterocyte back to the gut lumen, resulting in a further increase in the fraction of drug absorbed. Some calcium channel antagonists, benzodiazepines, HMG-CoA reductase inhibitors and cyclosporine are the most affected drugs. A single exposure to one glass of the juice can usually produce the maximal magnitude of the interaction. The data available so far, concerning this interaction and its clinical implications, are reviewed in this article. It is likely that more information regarding this interaction will accumulate in the future, and awareness of such is necessary for achieving optimal drug therapy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2002

Recommended micronutrient supplementation for institutionalized elderly.

A committee nominated by the Israel Ministry of Health examined the relevant literature and the local recommendations as well as the recommendations from other countries and suggested a daily micronutrient supplementation for institutionalized elderly living in institutions supervised by the Ministry of Health. The micronutrient preparatory, tailored for this population, is designed to contain about half the RDA for most of the vitamins and some microelements. Biotin and vitamins C, D and B12 as well as zinc, copper, chromium and molybdenum are suggested at a level higher than half the RDA, whereas fluorine, at a lower level. Major elements (calcium, magnesium and phosphorus) are excluded and should be supplied separately. Vitamin K and iron are also excluded. Fat-soluble vitamins should be microencapsulated. Micronutrient supplementation for institutionalized elderly is part of the Ministry of Health s balanced nutrition policy. The committee s recommendations are also applicable to the free-living elderly population.

Journal Article↗
PubMed2001

[Micronutrient (vitamins and minerals) supplementation for the elderly, suggested by a special committee nominated by Ministry of Health].

The elderly tend to be at a higher risk for nutritional deficiencies and in particular for micronutrient deficiencies. A committee nominated by Ministry of Health examined the relevant literature and the local recommendations as well as the recommendations from other countries and suggested a daily special micronutrient supplementation for institutionalized elderly. The preparatory will contain about half the RDA for most of the micronutrients, except for fluorine that is recommended at a lower level and biotin, vitamins D, C, B12 as well as zinc, copper and molybdenum at a level higher than half the RDA. Major elements such as calcium, are not included in the preparatory and would be supplied separately when needed. Vitamin K and iron are excluded as well. The suggested preparatory composition, mg: vitamin A, 0.450; vitamin D, 0.015; vitamin E, 10; thiamin, 0.6 Pound riboflavin, 0.7; biotin, 0.030; pantothenic acid, 3; niacin, 8; vitamin C, 60; vitamin B6, 0.8; folic acid, 0.120; vitamin B12, 0.0024; choline up to 275; zinc, 8; copper, 0.9; fluorine, 0.5; manganese, 1.2; chromium 0.020; molybdenum, 0.045; selenium, 0.030; and iodine, 0.075. Fat-soluble vitamins should be microencapsulated. Micronutrient supplementation is part of Ministry of Health balanced nutrition policy. The committees recommendations are also applicable for the free-living elderly.

Aged↗
PubMed1997

Subclinical hallucinations and delusions in nonpsychotic adolescents.

A number of studies have suggested that clinical populations of adolescents may report hallucinations and/or delusions without meeting criteria for a psychotic disorder. The purpose of this study was to provide information about the prevalence and symptom correlates of these subclinical hallucinations and delusions that occur in a nonpsychotic population of adolescents. Thirty-eight adolescents from a residential program and day treatment center were assessed with respect to hallucinatory experiences, ideas of reference, paranoid ideation, dissociative experiences, depressive symptomatology, and schizotypal cognitions. Results of this study indicated that 33% of the participants reported having experienced auditory hallucinations, and 24% reported having had delusional ideas. In addition, the results suggest that subclinical auditory hallucinations may have an especially strong relation with dissociative processes, whereas subclinical delusions appeared to be most strongly correlated with schizotypal thought processes. The results of this study begin to clarify the phenomenon of hallucinatory and delusional experiences in a nonpsychotic population.

Adolescent↗
PubMed1987

Erythromycin-induced drug interactions. An illustrative case and review of the literature.

The authors report a case of erythromycin-induced carbamazepine toxicity in a 6-year-old child following use of erythromycin ethylsuccinate (50 mg/kg/day). Within 5 days of erythromycin use, vomiting, weakness, lethargy, ataxia, nystagmus, and cogwheeling movements developed. A serum carbamazepine concentration had increased from 11.9 mg/L (measured 1 week prior to antibiotic use) to 25.8 mg/L. Following erythromycin withdrawal, serum concentrations returned toward baseline, and symptoms resolved. Erythromycin has known effects on hepatic enzyme function, with altered cytochrome P-450 function. The dramatic reduction in carbamazepine clearance observed in this patient is similar to that reported when erythromycin is used concurrently with other drugs. A brief review of potentially significant erythromycin drug interactions is presented.

Carbamazepine↗
PubMed1986

Proactive and retroactive effects of repeated electroconvulsive shock on passive avoidance retention in rats.

In spite of technical modifications, the therapeutic administration of electroconvulsive shock (ECS) to humans is still associated with significant memory impairment. Studies aimed at elucidating the neurobiologic basis of this impairment and developing appropriate treatment approaches have been limited by the absence of an appropriate animal model. We report here that ECS administered daily for 1-7 days to male albino rats (ECS X 1-ECS X 7) cumulatively impaired retention of passive avoidance when animals were trained 24 hours after the last ECS and tested 24 hours after training. Retention was directly proportional to the interval between training and testing; animals trained 24 hours after ECS X 7 and tested 1 hour later showed no deficit while animals tested after 24 hours showed maximal impairment. Retention was significantly improved by 10 days following the last of ECS X 7 and intact by 21 days. These findings parallel the effects of ECS on memory function in humans. The retrograde effects of ECS also paralleled those demonstrated in humans; while retention of a passive avoidance task learned 24 hours before ECS X 7 was grossly impaired, retention was intact if learning took place 7 days before the ECS course. The application of these findings as an animal model of ECS-induced memory impairment in humans, is discussed.

Amnesia↗
PubMed1984

Electroconvulsive shock and brain muscarinic receptors: relationship to anterograde amnesia.

Rats were administered one electroconvulsive shock daily for 7 days (ECS X 7) and were killed 24 hours after the last treatment. Muscarinic cholinergic receptor number, as determined by [3H] quinuclidinyl benzilate [( 3H]QNB) binding, was significantly reduced in the cerebral cortex. A parallel group of rats was trained on a passive avoidance task 24 hours following the last ECS and tested for retention of the original avoidance response 24 hours later; these animals exhibited a profound amnesia. Animals tested 1 hour following training were not amnestic, indicating that learning was unimpaired. Animals trained 7 days following ECS X 7 were not amnestic and [3H] QNB binding changes were not demonstrable at this time. A single ECS which does not significantly affect cortical [3H] QNB binding, did not induce amnesia in rats trained 24 hours after the treatment and tested 24 hours later. The parallel, cumulative nature of ECS-induced muscarinic receptor down-regulation and ECS-induced anterograde amnesia suggests a possible causative relationship.

Amnesia↗
PubMed1984

Enhancement of memory by a cholinesterase inhibitor associated with muscarinic receptor down-regulation.

Rats trained on a passive avoidance task 24 hours following a single intraperitoneal injection of diisopropyl fluorophosphate (DFP, 1.2 mg/kg) showed enhanced retention when tested 7 days later. In a parallel group of rats, reduced cortical [3H] quinuclidinyl benzilate binding was demonstrable 24 hours following DFP administration. The association of reduced muscarinic receptor binding and enhanced performance on a memory task contradicts previous reports which suggested that retention was impaired by treatments which down-regulate muscarinic receptors. This contradiction may be reconciled if pre-synaptic factors such as agonist availability are considered in conjunction with post-synaptic receptor effects.

Analysis of Variance↗
PubMed1984

Late results following surgical management of vascular graft infection.

Ninety-two patients underwent surgical treatment for 59 prosthetic graft infections and 33 secondary aortoenteric fistulas. Definitive treatment was accomplished with a low perioperative mortality rate (14%). Long-term follow-up confirmed that most patients were cured of their infection or fistula, and 88% of the patients who survived the perioperative period (67 of 76) had no further evidence of infection when followed up from 10 months to 12 1/2 years postoperatively. The 12% late mortality rate (9 of 76) was secondary to persistent infection and aortic stump disruption. When perioperative and late deaths in both groups are combined, 67 of 92 patients (73%) were cured of their prosthetic graft infection. Factors associated with a favorable prognosis for survival and cure of infection were autogenous reconstruction and possibly staged operative repair. Poor prognosis for survival and cure of infection resulted from aortic stump disruption, persistent infection, and retained graft material. Significant morbidity (amputation and multiple operative procedures) was related to the severity of underlying vascular disease, the inadequacy of extra-anatomic reconstruction, and in some cases progression of vascular disease. The major challenges in the treatment of graft infection at present are the preoperative identification of limited graft infection and the successful management of the interrupted aorta. Complex and innovative reconstructive procedures continue to be necessary to ensure limb salvage and remain a considerable technical challenge. Nonetheless, the prospects for cure as reported in this series justify an aggressive operative approach. A successful outcome following definitive treatment of these devastating complications is possible for the majority of affected patients.

Aged↗
PubMed1983

Acquired angiodysplasia as a cause of gastric hemorrhage: a possible consequence of cholesterol embolization.

A patient with aortic stenosis and gastrointestinal bleeding due to angiodysplastic (telangiectatic) lesions in the stomach is presented. Biopsy of the lesions showed cholesterol emboli with granuloma formation, intramucosal vascular obstruction, subepithelial ectatic vessels, and epithelial atrophy. The case history appeared to indicate the formation of new lesions over time and a tendency to a regression of some of the least advanced lesions. It is suggested that cholesterol showers from the aortic valve or atheromatous aortic plaques may be one cause of acquired angiodysplastic lesions in the gastrointestinal tract.

Aged↗
PubMed1976

Occurrence of primary hepatocellular cancer and peliosis hepatis after treatment with androgenic steroids.

Three patients are reported in whom treatment of Fanconi's anaemia with androgenic steroids was complicated by the development of either primary hepatocellular cancer (PHC) or peliosis hepatis. The first, a White woman aged 34 years, was found to have PHC after receiving first methyltestosterone and then oxymetholone for a total period of 7 years. She died 4 months after the diagnosis was made. The other 2 patients were White children who presented with peliosis hepatis after receiving methyltestosterone and oxymetholone for 8 years and oxymetholone for 5 years, respectively. Both died from their primary diseases shortly after oxymetholone treatment was discontinued. Possible pathogenic mechanisms involved in the development of these serious complications are discussed and the therapeutic dilemma raised by their occurrence is emphasised.

Adolescent↗
PubMed1975

Accuracy of actuarial and clinical predictions for length of stay and unauthorized absence.

Multivariate-equation predictions of length of hospital stay and probability of unauthorized absence were compared with similar predictions made by clincians and actual outcome for 167 patients drawn from a random sample of admissions during a two-month period at five state hospitals. The computer proved to be about as accurate as clinicians in predicting length of stay. Neither computer nor clinician was able to usefully predict unauthorized absence because of its infrquent occurrance. Use and improvement of such actuarial predictions within the Missouri automated data base were discussed.

Diagnosis, Computer-Assisted↗