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Biomedical subjects

D Friedman

Publications and source records attributed to D Friedman.

At least 217 records · Page 12Linked to original sources
PubMed1985

Influence of life-style on the premenstrual syndrome. Analysis of a questionnaire survey.

The premenstrual syndrome (PMS) is influenced by parameters of life-style. An analysis was done of 384 questionnaires completed by women with a wide variety of life-styles. Four measures of PMS symptomatology were developed to assess the areas of edema, autonomic responses, affect and coping mechanisms. Significance associations were found between PMS symptomatology and regularity of periods, occupational level and educational attainment. Housewives were found to report the highest levels of symptom expression. Visits to physicians due to PMS were found to be higher than is usually reported in the medical literature.

Adaptation, Psychological↗
PubMed1984

In vivo evaluation of postoperative immunosuppression by means of Multitest system.

The Multitest System, a new standardized method for evaluating delayed hypersensitivity and cell mediated immunity was carried out before surgery and throughout the postoperative care in subjects undergoing gastrointestinal surgery. In all patients significantly depressed cutaneous reactions were found in the first day after operation. Immunosuppression lasted more than four days when postoperative infection has set up, while in uneventful patients delayed hypersensitivity has returned to preoperative values from the fourth day. It would be suggested that Multitest System data in fourth postoperative day could identify subjects with uneventful recovery after surgery.

Adult↗
PubMed1984

P300 and slow wave: the effects of reaction time quartile.

Event-related potentials (ERPs) were recorded from 25 adolescents in a modification of the odd-ball paradigm. On alternate blocks subjects were required to detect either a missing stimulus or a change in pitch, each of which occurred 17% of the time and was embedded in a series of background tone pips (66% occurrence). The study was designed to assess the relationship between P300 and Slow Wave elicited by two infrequent targets which differed in the amount of temporal uncertainty (and thus, equivocation) associated with them. Principal components analyses (PCAs) were used in an attempt to reduce overlap among components. Stimulus-synchronized (SSA) and response-synchronized (RSA) averages were computed for correct trials only in association with the first (Q1) and fourth (Q4) reaction time (RT) quartiles. Measurement of the SSAs replicated the results of Roth, Ford and Kopell (1978): P300 amplitude was larger in Q1 than in Q4, while Slow Wave amplitude increased in Q4 relative to Q1. In the RSAs for Slow Wave, only the frontally negative aspect remained larger in Q4 than in Q1, while the parietally positive component did not differ between quartiles. The PCA basis waves showed that the major portions of P300 and Slow Wave followed response execution, thus precluding their involvement in the discrimination process per se. These results support the functional dissociation of P300 and Slow Wave and the functional independence of the frontal and parietal aspects of Slow Wave.

Adolescent↗
PubMed1984

Premenstrual syndrome.

Symptoms related to the premenstrual syndrome (PMS) are experienced by a large segment of the susceptible population. Its nature and the extent to which it is a problem are not well delineated and are subjects of significant controversy. Its etiology is uncertain. Cortical centers and neurotransmitters appear to play an important role. Its influence on the expression of other diseases and their influence on its presence or its severity have received insufficient study. Various approaches to therapy are commonly used, including birth control pills, diuretics, minor tranquilizers, and bromocriptine, but no single drug therapy is consistently effective. A strong placebo effect has been demonstrated with all medications that have been used.

Adolescent↗
PubMed1983

The multitest system for delayed hypersensitivity evaluation. Standardized result in an Italian adult population.

Delayed hypersensitivity was evaluated by means of Multitest System in 50 healthy Italian adults. Results were checked for homogeneity, comparability and reliability assays. Strict antigen and technique standardization warranted closely homogeneous results. Booster effect did not occur. Data evaluation was not depending on individual reader. Multitest System appears to be the most reliable method to evaluate delayed hypersensitivity and cellular immunity in man.

Adult↗
PubMed1983

Presence of a sodium-potassium chloride cotransport system in the rectal gland of Squalus acanthias.

In order to investigate whether the loop diuretic sensitive, sodium-chloride cotransport system described previously in shark rectal gland is in fact a sodium-potassium chloride cotransport system, plasma membrane vesicles were isolated from rectal glands of Squalus acanthias and sodium and rubidium uptake were measured by a rapid filtration technique. In addition, the binding of N-methylfurosemide to the membranes was investigated. Sodium uptake into the vesicles in the presence of a 170 mM KCl gradient was initially about five-fold higher than in the presence of a 170 mM KNO3 gradient. In the presence of chloride, sodium uptake was inhibited 56% by 0.4 mM bumetanide and 40% by 0.8 mM N-methylfurosemide. When potassium chloride was replaced by choline chloride or lithium chloride, sodium uptake decreased to the values observed in the presence of potassium nitrate. Replacement of potassium chloride by rubidium chloride, however, did not change sodium uptake. Initial rubidium uptake into the membrane vesicles was about 2.5-fold higher in the presence of a 170 mM NaCl gradient than in the presence of a 170 mM NaNO3 gradient. The effect of chloride was completely abolished by 0.4 mM bumetanide. Replacement of the sodium chloride gradient by a lithium chloride gradient decreased rubidium uptake by about 40%; replacement by a choline chloride gradient reduced the uptake even further. Rubidium uptake was also strongly inhibited by potassium. Sodium chloride dependence and bumetanide inhibition of rubidium flux were also found in tracer exchange experiments in the absence of salt gradients. The isolated plasma membranes bound 3[H]-N-methylfurosemide in a dose-dependent manner. In Scatchard plots, one saturable component could be detected with an apparent KD of 3.5 x 10(-6) M and a number of sites n of 104 pmol/mg protein. At 0.8 microM, N-methylfurosemide binding decreased 51% when sodium-free or low-potassium media were used. The same decrease was observed when the chloride concentration was increased from 200 to 600 mM or when 600 1 mM bumetanide or furosemide was added to the incubation medium. These studies indicate that the sodium-chloride cotransport system described previously in the rectal gland is in fact a sodium-potassium chloride cotransport system. It is postulated that this transport system plays an essential role in the secondary active chloride secretion of the rectal gland.

Animals↗
PubMed1983

Anxiety disorders.

The Diagnostic and Statistical Manual of Mental Disorders (DSM-III) has expanded descriptions of anxiety and includes new categories with definitive diagnostic criteria. It has also eliminated its previous psychodynamic and psychoanalytic approach to psychopathology. The new anxiety classifications reflect the growth of knowledge in neurochemistry, especially cell-membrane binding sites and specific pharmacologic actions of certain drugs. Many research conclusions have become questionable as a result in large part of their reliance upon the obsolete versions of DSM (I and II). Among major findings in research on anxiety are its relatively common incidence, especially in family practice, and its relationship to secondary depression and increased association with physical disorders, particularly if the anxiety disorder is of long duration. Family and genetic studies have revealed a high incidence of anxiety within families, though there is little evidence of heritability. The pathophysiology of anxiety is only beginning to be studied productively. Research in drug therapy and psychotherapy have supported the need for both therapeutic modalities in most circumstances.

Anti-Anxiety Agents↗
PubMed1983

Experimental Staphylococcus epidermidis endocarditis in rabbit model.

To study the natural course of catheter-induced endocarditis secondarily infected with Staphylococcus epidermidis, 29 rabbits had catheters introduced surgically through the carotid artery to the aortic valve. Forty-eight hours later the catheters were removed from five rabbits. The rabbits were inoculated intravenously with 10(8) colony-forming units of S epidermidis. Autopsies done at various intervals showed all rabbits with indwelling catheters had noticeable aortic valve vegetations with positive cultures for S epidermidis. In the group with catheters removed after 48 hours, less severe valvular lesions were noted. Metastatic seeding to kidneys, spleen, and liver were noted in both groups. Because of low cure rate in the treatment of S epidermidis endocarditis, this rabbit model could be used to study antibiotic regimens for valvular endocarditis.

Animals↗
PubMed1982

Cognitive brain potentials in children at risk for schizophrenia: preliminary findings.

Event-related brain potentials were recorded to auditory stimuli from children at risk for schizophrenia and normal control children who were part of two independent samples being followed longitudinally. Subjects were required to detect (with a reaction time response) one of two infrequent events (either a pitch change or a missing stimulus), each of which occurred 17 percent of the time, and was embedded in a sequence of frequent events occurring 66 percent of the time. The event-related potential (ERP) elicited by both infrequent stimuli consisted of a positive-going wave peaking at 350 msec for the pitch change ERP (P350) and 400 msec for the missing stimulus ERP (P400) and a slow wave, which overlapped with and extended beyond the P350 and P400 potentials. When the eliciting event was relevant, these potentials were significantly larger than when it was irrelevant. When the waveforms by the highrisk (HR) subjects were compared to those produced by the normal control (NC) subjects, the HR subjects of both samples showed significantly less late positive amplitude (P350 and P400) than the NC subjects, but only when the eliciting event was relevant. This effect appeared to be independent of reaction time, as reaction time means and variances were quite similar between risk groups. Other possible explanations for this amplitude reduction were explored. Since late positive component amplitude reduction has been consistently reported to characterize the waveforms of adult schizophrenics, the reduction seen in children at genetic risk for schizophrenia may be a premorbid indicator for the development of the psychosis.

Adolescent↗
PubMed1982

A flexible restraint chair for the cynomolgus monkey (Macaca fascicularis).

We have found that commercial restraint chairs suitable for the rhesus monkey (Macaca mulatta) cause severe physical distress to many cynomolgus monkeys (Macaca fascicularis). A new restraint chair has therefore been designed specifically for the cynomolgus. The key features of the chair are an angled neck piece, a large opening to provide free movement for the tail, a soft waist restraint, and a level surface for both the heels and ischial pads. This new chair is not only suitable for the cynomolgus monkey but may also be more comfortable for the rhesus monkey than standard commercial chairs.

Animals↗
PubMed1981

[Evaluation of blood flow using a reservoir flowmeter of several types of arteriovenous fistulas in chronic hemodialysis treatment].

Blood flow of nine end to end and eight side to side arteriovenous fistulas (AVF) at distal forearm for maintenance hemodialysis, was measured by blood flowmeter inserted in the arterial line between the pump and the dialyzer. The mean flow of the end to end and the side to side fistulas was 386.6 +/- 69.6 ml/min and 345 +/- 45 ml/min (p 0.01) respectively. Since, in addition, the end to end flow seems to be better than the side to side flow as regards local and general effects, we advocate the use of end to end fistulas.

Adult↗
PubMed1981

Endodontic treatment of teeth with periapical radiolucent areas in a general dental practice.

Clinical details of 192 teeth with preoperative periapical radiolucent areas, treated endodontically, are described. The presenting signs and symptoms as well as some postoperative observations are listed. Periapical radiolucent areas were most frequently found related to maxillary teeth: 55 percent were adjacent to teeth with a single root canal and 30 percent related to teeth with three root canals. Radiographic follow-up 1 or more years after therapy was possible in 125 of the root-filled teeth: of those teeth, 59 percent shows disappearance of the radiolucent area and 29 percent exhibited a decrease in size of the area. The degree of success did not appear to be related to the number of root canals filled per tooth but, rather, to whether or not the root filling was short of the radiographic apex. In addition, the prognosis made at the time of root filling was accurate in most cases when compared to the estimated success rates.

Adolescent↗
PubMed1981

lambda altSF: a phage variant that acquired the ability to substitute specific sets of genes at high frequency.

We report the isolation of lambda altSF, a variant of Escherichia coli phage lambda that substitutes sets of genes at high frequency. Two forms of the variant phage have been studied: lambda altSF lambda, which exhibits the immunity (repressor recognition) of phage lambda, and lambda altSF22, which exhibits the immunity of Salmonella phage P22. Lysates made from single plaques of lambda altSF lambda contain 10-30% phage of the P22 form. Similarly, lysates from single plaques of lambda altSF22 contain as much as 1% phage of the lambda form. Heteroduplex analyses reveal the following features of the lambda altSF chromosomes: (i) each form has the immunity genes appropriate to its immune phenotype, (ii) the substituted segments include genes involved in regulation and replication, and (iii) the alt phages have unusual additions and substitutions of DNA not normally found associated with either immunity region. In the case of lambda altSF lambda, there is a small insertion in the region of the cI gene. Because revertants that lose this inserted DNA concomitantly lose the ability to substitute, we conclude that the insertion plays a role in the substitution process. In the case of change from lambda altSF lambda to lambda altSF22, the substituting P22 genes are derived from the E. coli host. We have identified a set of Salmonella phage P22 genes in a standard nonlysogenic strain of E. coli K-12 that is apparently carried in a silent form. The reason for this lack of expression is not obvious, because this P22 material includes structural genes and associated promoters and is potentially active. When this set of genes substitutes for the analogous set of genetic material on the genome of lambda altSF lambda, the P22 genes are expressed in a normal manner.

Bacteriophage lambda↗