PubMed Health⌕ Search

Biomedical subjects

H Falk

Publications and source records attributed to H Falk.

At least 19 recordsLinked to original sources
PubMed1992

Survey of advertising for nutritional supplements in health and bodybuilding magazines.

The use of food supplements by the general public is poorly quantified, and little information on this subject is available in the medical literature. We surveyed 12 recent issues of popular health and bodybuilding magazines (1) to quantify the number of advertisements for food supplements, the number of products advertised, and the number and type of ingredients in these products; (2) to identify the purported health benefits of these products; and (3) as a preliminary effort to identify areas for future research. We counted 89 brands, 311 products, and 235 unique ingredients, the most frequent of which were unspecified amino acids; the most frequently promoted health benefit was muscle growth. We also found many unusual or unidentifiable ingredients, and 22.2% of the products had no ingredients listed in their advertisements. Health professionals may not be aware of how popular food supplements are or of a particular supplement's potential effects or side effects. In addition, patients may be reluctant to discuss their use of these products with traditional medical practitioners. We recommend that routine history taking include specific questions about patients' use of food supplements and that any possible adverse effects or side effects be reported to public health authorities.

Advertising↗
PubMed1992

Eosinophilia-myalgia syndrome in L-tryptophan-exposed patients.

OBJECTIVES: To study the incidence of eosinophilia-myalgia syndrome, the risk factors associated with the syndrome, and the clinical spectrum of illness associated with L-tryptophan use in an exposed population. DESIGN: Retrospective cohort and nested case-control studies of risk factors for eosinophilia-myalgia syndrome using inpatient and outpatient chart reviews, telephone interviews, and in-person patient interviews. Descriptive study of clinical course of L-tryptophan users. SETTING: Office practice of one psychiatrist based in a small city (population 43,467) in South Carolina. PATIENTS: Eligible subjects were all patients from the practice who used L-tryptophan during the 1989 study interval. Of these, 418 (87%) were interviewed. MAIN OUTCOME MEASURES: Clinical spectrum of illness associated with L-tryptophan use, including definite and possible cases of eosinophilia-myalgia syndrome. RESULTS: Among the 418 interviewed L-tryptophan users, we identified 47 definite cases (11%) and 68 possible cases (16%) of eosinophilia-myalgia syndrome, most of which involved patients who were using one retail brand of L-tryptophan (brand A). Among the 157 brand A users, we identified 45 definite cases (29%) and 36 possible cases (23%) of eosinophilia-myalgia syndrome, and the risk for the syndrome increased as the brand A dose increased. Fifty percent (19 of 38) of those using more than 4000 mg/day developed definite eosinophilia-myalgia syndrome, and 84% (32 of 38) developed either definite or possible eosinophilia-myalgia syndrome. On multivariate analysis, risk for definite eosinophilia-myalgia syndrome was associated with brand A dose and age of the patient; however, gender, race, and use of other medications were not associated with the syndrome. CONCLUSIONS: These results suggest that many people exposed to the agent causing eosinophilia-myalgia syndrome may develop illness, and dose of presumably contaminated L-tryptophan is the single most important predictor of eosinophilia-myalgia syndrome. The broad range of signs and symptoms reported by patients using L-tryptophan illustrates that a strict case definition may identify only about half of those affected.

Adult↗
PubMed1991

Long-term prognosis of extensive polyunit cantilevered fixed partial dentures.

The aim of this retrospective study was to elucidate the long-term prognoses of extensive fixed partial dentures including unilateral or bilateral polyunit cantilevers in patients with healthy but reduced periodontal support. Following periodontal therapy 36 cross-arch fixed partial dentures with two or more cantilever units unilaterally or bilaterally were fitted in 34 patients. In the prosthodontic design, special attention was given to the retention to long parallel preparations, to the dimensions of the framework, and to the occlusal design. After completion of therapy, the patients were enrolled in a regular maintenance care program and followed up for a period of 5 to 12 years. During this follow-up period one abutment tooth was fractured in one patient. One fixed partial denture with extremely reduced periodontal support was lost as a result of complete periodontal breakdown from occlusal trauma. For 33 fixed partial dentures, neither periodontal nor technical complications occurred.

Dental Abutments↗
PubMed1991

cis Acting RNA sequences control the gag-pol translation readthrough in murine leukemia virus.

The pol gene of the Moloney murine leukemia virus (M-MuLV) is expressed as a Gag-Pol fusion protein through an in-frame suppression of the UAG termination codon located between the two genes. The role of nucleotide context in suppression was investigated, in a rabbit reticulocyte lysate translation system, using site-directed mutagenesis. The results indicate that the translational readthrough is mediated by at least 50 bases long RNA sequence located 3' to the gag UAG termination codon. Within this sequence a short purine-rich sequence adjacent to the amber codon, highly conserved among different retroviruses, appears essential for M-MuLV suppression. Two alternative putative stem and loop like RNA structures can be drawn at the gag-pol junction, one abutting the gag UAG codon, and the second downstream to it. None of these structures appears to be important to the suppression process.

Animals↗
PubMed1991

Toxic oil syndrome: a current clinical and epidemiologic summary, including comparisons with the eosinophilia-myalgia syndrome.

In the spring and summer of 1981, an epidemic of a new illness now referred to as the toxic oil syndrome occurred in central and northwestern Spain, resulting in some 20,000 cases, 12,000 hospital admissions and greater than 300 deaths in the 1st year of the epidemic. The initial onset of illness was usually acute, and patients presented primarily with a respiratory syndrome involving cough, fever, dyspnea, hypoxemia, pulmonary infiltrates and pleural effusions. While approximately 50% of patients recovered from this acute phase of the illness without apparent sequelae, the remaining patients developed an intermediate or chronic phase, or both, of illness involving severe myalgia, eosinophilia, peripheral nerve damage, sclerodermiform skin lesions, sicca syndrome, alopecia and joint contractures, among other findings. Epidemiologic and analytic chemical studies have clearly linked the toxic oil syndrome to the ingestion of oil mixtures containing rapeseed oil denatured with aniline. However, the precise identity of the etiologic agent within this oil has never been determined. Aniline itself did not cause the illness, but the causal agent may be a reaction product of aniline with some oil component. Although many aspects of disease activity in the involved patients have lessened with time, the ultimate consequences of their disease are not clear and are the subject of ongoing study. The recently described eosinophilia-myalgia syndrome in the United States clinically resembles the toxic oil syndrome.

Aniline Compounds↗
PubMed1991

The effect of constant light and phase shifts on a learned time-place association in garden warblers (Sylvia borin): hourglass or circadian clock?

Garden warblers are able to learn an association between time of day and feeding place. In constant dim light and constant food availability, the learned feeding pattern (successive visits to four feeding rooms for approximately 3 hr each) persisted for at least 1 day in three birds and for at least 6 days in one bird. The free-running feeding rhythm had a period of slightly greater than 23 hr. In response to a 6-hr phase advance of the light-dark cycle, the birds advanced their learned feeding pattern by 2.6 hr on the first day, whereas a 6-hr phase delay had no significant effect. These results are consistent with the hypothesis that the birds use a circadian clock rather than an hourglass mechanism of timing. This conclusion is further supported by the response of birds to forced interruptions of the daily feeding pattern (Krebs and Biebach, 1989).

Animals↗
PubMed1991

The eosinophilia-myalgia syndrome: the Los Alamos Conference.

On June 12 and 13, 1990 the Los Alamos National Laboratory in cooperation with the New Mexico Department of Health and Environment, the Centers for Disease Control (CDC), the Food and Drug Administration (FDA), and the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health (NIH) hosted a conference on the eosinophilia-myalgia syndrome. Fifty presentations covered a variety of important issues which are summarized herein.

Centers for Disease Control and Prevention, U.S.↗
PubMed1990

Nuclear-magnetic-resonance investigations of the biliverdin-apomyoglobin complex.

The recently described biliverdin-apomyoglobin complex has been investigated by two-dimensional NMR methods and molecular modeling with respect to the geometry of the chromophore and its position within the myoglobin pocket. Nuclear Overhauser effect correlations between the ligand and apoprotein amino acid residues prove that the bile pigment assumes a cyclic helical conformation and a position similar to heme in native myoglobin.

Animals↗
PubMed1990

Eosinophilia-myalgia syndrome. Results of national surveillance.

Eosinophilia-myalgia syndrome, a newly recognized disorder that occurred in epidemic proportions during 1989, is associated with ingestion of manufactured tryptophan. A case is defined by debilitating myalgias and absolute eosinophilia greater than or equal to 1.0 x 10(9) cells/L. As of July 10, 1990, a total of 1531 cases had been reported nationwide, including 27 deaths. The highest rates of reported illness are concentrated in the western states, 68% are non-Hispanic white women aged 35 years and older, and data on associated clinical findings suggest a multisystemic disorder. The most frequent features include arthralgia (73%), rash (60%), cough or dyspnea (59%), peripheral edema (59%), elevated aldolase level (46%), and elevations in the results of liver function tests (43%). Neuropathy or neuritis, resulting in paralysis and death in some patients, was seen in 27%, and chest roentgenogram abnormalities were noted in 21% of those tested. Ninety-one percent reported onset of symptoms during or after May 1989, and 97% reported having taken tryptophan before the onset of symptoms. Since the recall of over-the-counter preparations of tryptophan in November 1989, the number of new cases of this potentially fatal disorder has fallen dramatically.

Adolescent↗
PubMed1990

On occlusal forces in dentitions with implant-supported fixed cantilever prostheses.

The main aims of this thesis were (1) to study the functional characteristics of dentitions with mandibular implant-supported fixed cantilever prostheses - IFCP s- occluding with complete dentures, (2) to study in detail the magnitudes and distributions of axially directed closing and chewing forces in such dentitions, (3) to study the influence of number and distribution of occlusal contacts on the magnitude and distribution of closing and chewing forces, (4) to assess the vertical bending moment and the resulting vertical bending stress in the cantilever joints and (5) to find out whether the force distribution over the cantilever beams and the resulting vertical bending stress in the cantilever joint are influenced by the type of prosthetic construction in the opposing jaw. Closing and chewing forces were registered in altogether seventeen subjects by means of miniature strain gauge transducers mounted bilaterally and symmetrically in performed matrices in prosthetic appliances. Four, six or eight transducers, evenly distributed over the tooth-arch, permitted registrations of axially directed occlusal forces in several occluding areas simultaneously. In Papers I-IV, the implant-supported prostheses were installed in the mandible and occluded with complete dentures. In Paper V, group A, the fixture-supported prostheses were installed in the maxilla and occluded with tooth-supported fixed partial dentures whereas in group B, the arrangements were analogous to those in Papers I-IV. All subjects exhibited a rhythmic chewing pattern and preferred one side for chewing although both sides were used. Most chewing sequences were terminated with swallowing with occlusal force development. The mean total forces acting over the tooth-arch varied somewhat between groups and occlusal arrangements but averaged 350 and 170 N for closing and chewing respectively. Closing and chewing forces increased distally along the cantilever beams when occluding with complete dentures and decreased distally when occluding with fixed partial dentures. The distally increasing force distribution pattern could be altered to a distally decreasing force distribution pattern by infraoccluding the second cantilever unit by as little as 100 microns. Calculated vertical bending moments and stresses in the cantilever joints of the preferred chewing sides created by closing and chewing forces were larger in dentitions where the IFCP occluded with a complete denture than in dentitions where the IFCP occluded with a tooth-supported fixed partial denture.

Adult↗
PubMed1990

Genetic loci ordering instability: an example.

In attempting to establish the order of genetic loci by constructing a map from pairwise linkage data, one assumes that the loci satisfy a linear-order relation. If the data utilized in the construction are not consistent with the linear-order assumption, then a very small change in the data may lead to a large qualitative change in the map. An example of such an instability is presented in this paper.

Chromosome Mapping↗
PubMed1990

Occlusal interferences and cantilever joint stress in implant-supported prostheses occluding with complete dentures.

Naturally occurring closing and chewing forces were measured in dentitions with mandibular fixture-supported bilateral distal two-unit cantilever fixed prostheses occluding with complete dentures, and the vertical bending stress in the cantilever joint of the preferred chewing side was assessed. Occlusal forces were measured using eight miniature strain gauge transducers bilaterally and symmetrically mounted in complete dentures. Occlusal forces over the entire prosthesis were registered in basic (habitual) occlusion and with a 100-microns-high premature occlusal contact on the second cantilever unit. Closing and chewing forces increased distally. The premature occlusal contact did not significantly influence the total forces over the entire dentition but increased the local forces over the second cantilever unit. The group mean maximal vertical bending stress for closing forces reached the fatigue limit for unhardened type III dental gold alloy in basic occlusion. Although the interfered occlusion resulted in a significant redistribution of forces and significantly altered the stress contributions from each cantilever unit, maximal vertical bending stress in the cantilever joint was not significantly influenced. During chewing, the fatigue limit was not reached in basic or in interfered occlusion.

Adult↗
PubMed1989

How to build an inexpensive cyclotherm instrument for automated polymerase chain reaction.

The Cyclotherm instrument is a functionally fully equivalent but inexpensive alternative to commercial instruments for automated polymerase chain reaction (PCR). It can be rebuilt under conditions of a biochemical laboratory for less than +1000. A Peltier element is used for heating and cooling of the reaction vials and the temperature and timing of the PCR cycles are controlled by a BASIC program in a SHARP PC 1600 low cost computer.

Computer Systems↗
PubMed1989

Periodontal conditions in insulin-dependent diabetics.

The aim of this study was to compare the prevalence and severity of periodontal disease in age- and sex-matched adult long- and short-duration insulin-dependent diabetics and non-diabetics. The study involved 82 subjects with long- and 72 with short-duration diabetes and 77 non-diabetics, all aged 20-70 years. The clinical and radiographic examination comprised recordings of the number of existing teeth, absence or presence of plaque and supra- and subgingival calculus, gingival conditions, probing pocket depth and alveolar bone level. There were no significant differences in the number of existing teeth or presence of plaque and supra- and subgingival calculus between long- and short-duration diabetics and non-diabetics. Diabetics, irrespective of the duration of the disease, had a higher prevalence of sites with gingivitis than non-diabetics. Overall, there were no significant differences between the groups regarding the prevalence of tooth surfaces with probing pocket depths of 4 and 5 mm. However, on comparison between age subgroups, long-duration diabetics younger than 45 years had significantly more 4 and 5 mm pockets than non-diabetics. Long-duration diabetics altogether had significantly more tooth surfaces with probing depth greater than or equal to 6 mm than non-diabetics. The radiographs of alveolar bone height exhibited significantly more extensive alveolar bone loss in long-duration diabetics aged 40-49 years than in short-duration diabetics and non-diabetics. This, together with the increased number of subjects belonging to classification groups with severe periodontal disease experience among long-duration diabetics, indicates more periodontal disease in these diabetics.

Adult↗
PubMed1989

Number of teeth, prevalence of caries and periapical lesions in insulin-dependent diabetics.

Ninety-four long and 86 short duration diabetics and 86 non-diabetics, aged 20-70 yr, participated in the study. The clinical and radiographic examination comprised recordings of the number of teeth, carious lesions, restorations, endodontically treated teeth and periapical lesions. There were no significant differences between long and short duration diabetics and non-diabetics in the number of teeth and the total number of decayed and filled tooth surfaces (DFS %). However, long duration diabetics exhibited more decayed proximal tooth surfaces (D %) than non-diabetics. There were no significant differences between long and short duration diabetics and non-diabetics in the mean number of endodontically treated teeth and periapical lesions. Women with long diabetes duration, however, exhibited more endodontically treated teeth with periapical lesions than women with short diabetes duration and women without diabetes. Long duration diabetics exhibited teeth with periapical lesions to a greater extent than the other groups. On the whole, diabetics and non-diabetics exhibited a similar caries frequency but among the diabetics there was a group of individuals who had more periapical lesions than the non-diabetics.

Adult↗
PubMed1989

Dental care habits and knowledge of oral health in insulin-dependent diabetics.

The aim of this study was to investigate dental care habits and knowledge of oral health in age- and sex-matched adult long and short duration insulin-dependent diabetics and non-diabetics. Ninety-four long and 86 short duration diabetics and 86 non-diabetics, aged 20-70 years, participated in the study. All subjects answered a questionnaire with 38 questions about dental visits, attitudes to and knowledge of dental diseases, toothcleaning, dietary and smoking habits, and oral sensations. Among the diabetics there was a rather large group that did not visit a dentist annually. The diabetics also required more emergency dental care and were not as willing as the non-diabetics to spend time and money on their teeth. The compliance with dietary advice was poor among the diabetics. Oral discomfort such as prickling and burning sensations, metallic and bad taste was rare in both diabetics and non-diabetics. In the diabetics, however, a feeling of mouth dryness was common.

Adult↗